id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/9311266 | null | Le Viet Dung and Nguyen Ai Viet | Heavy diquark in baryons containing a single heavy quark and the weak
form factors | 22 pages and 8 figures, Syracuse University Preprint SU-4240-562 | null | null | null | hep-ph | null | It is shown that the number of independent weak form factors collapses if the
heavy diquark exists inside the baryons containing a single heavy quark. The
relations between the weak form factors are quite different in the case of
light diquark. So a careful analysis on the future data of the weak form
factors would clarify that in those baryons the correlation between the heavy
quark and a light quark is stronger or weaker than the one between two light
quarks.
| [
{
"created": "Wed, 10 Nov 1993 18:56:00 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Nov 1993 22:54:00 GMT",
"version": "v2"
}
] | 2009-09-25 | [
[
"Dung",
"Le Viet",
""
],
[
"Viet",
"Nguyen Ai",
""
]
] | It is shown that the number of independent weak form factors collapses if the heavy diquark exists inside the baryons containing a single heavy quark. The relations between the weak form factors are quite different in the case of light diquark. So a careful analysis on the future data of the weak form factors would clarify that in those baryons the correlation between the heavy quark and a light quark is stronger or weaker than the one between two light quarks. |
1102.4466 | Dario Schalla | E. A. Paschos and Dario Schalla | Neutrino production of hadrons at low energy and in the small $Q^2$
region | 15 pages, 8 figures, comments added | Phys.Rev.D84:013004,2011 | 10.1103/PhysRevD.84.013004 | DO-TH-11/03 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use PCAC in the small $Q^2$ region in order to calculate the Adler sum
rule and the production of hadrons in the low energy region where resonances
dominate. We find very good agreement with the sum rule and with the computed
cross sections. We find a value $C_5^A(0)$ close to the Goldberger-Treiman
prediction. The formalism is general and can be applied to other reactions
shedding light into the dynamical transition from resonances to deep inelastic
scattering.
| [
{
"created": "Tue, 22 Feb 2011 11:25:40 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Apr 2011 17:35:08 GMT",
"version": "v2"
}
] | 2011-08-08 | [
[
"Paschos",
"E. A.",
""
],
[
"Schalla",
"Dario",
""
]
] | We use PCAC in the small $Q^2$ region in order to calculate the Adler sum rule and the production of hadrons in the low energy region where resonances dominate. We find very good agreement with the sum rule and with the computed cross sections. We find a value $C_5^A(0)$ close to the Goldberger-Treiman prediction. The formalism is general and can be applied to other reactions shedding light into the dynamical transition from resonances to deep inelastic scattering. |
1002.4043 | Magno Machado | M.B. Gay Ducati, M.M. Machado, M.V.T. Machado | Estimate of the single diffractive heavy quark production in heavy ion
collisions at the CERN-LHC | 8 pages, 3 tables. Version to be published in Physical Review D | Phys.Rev.D81:054034,2010 | 10.1103/PhysRevD.81.054034 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The single diffractive cross section for heavy quarks production is
calculated in next-no-leading order (NLO) in nucleus-nucleus collisions. Such
processes are expected to occur at the LHC. We start using the hard diffractive
factorization formalism, taking into account the recent experimental
parameterization for the Pomeron Structure Function (DPDF). Absorptive
corrections are accounted by the multiple Pomeron contributions considering a
gap survival probability, where its theoretical uncertainty for nuclear
collisions is discussed. We estimate the diffractive ratios for single
diffraction process in nuclear coherent/incoherent collisions at the LHC.
| [
{
"created": "Mon, 22 Feb 2010 03:03:34 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Mar 2010 23:57:14 GMT",
"version": "v2"
}
] | 2010-05-28 | [
[
"Ducati",
"M. B. Gay",
""
],
[
"Machado",
"M. M.",
""
],
[
"Machado",
"M. V. T.",
""
]
] | The single diffractive cross section for heavy quarks production is calculated in next-no-leading order (NLO) in nucleus-nucleus collisions. Such processes are expected to occur at the LHC. We start using the hard diffractive factorization formalism, taking into account the recent experimental parameterization for the Pomeron Structure Function (DPDF). Absorptive corrections are accounted by the multiple Pomeron contributions considering a gap survival probability, where its theoretical uncertainty for nuclear collisions is discussed. We estimate the diffractive ratios for single diffraction process in nuclear coherent/incoherent collisions at the LHC. |
2206.14965 | Yuji Koike | Riku Ikarashi, Yuji Koike, Kenta Yabe, and Shinsuke Yoshida | A New Derivation of the Twist-3 Gluon Fragmentation Contribution to
Polarized Hyperon Production | 15 pages, 1 figure | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | A novel method of formulating the twist-3 gluon fragmentation function
contribution to hyperon polarization in the proton-proton collision is
presented. The method employs a covariant gauge and takes full advantage of the
Ward-Takahashi identities before performing the collinear expansion. It
provides a robust way of constructing the general cross section formula, and
also a clear understanding for the absence of the ghost-like terms in the
twist-3 cross section in the leading order with respect to the QCD coupling
constant.
| [
{
"created": "Thu, 30 Jun 2022 01:26:40 GMT",
"version": "v1"
}
] | 2022-07-01 | [
[
"Ikarashi",
"Riku",
""
],
[
"Koike",
"Yuji",
""
],
[
"Yabe",
"Kenta",
""
],
[
"Yoshida",
"Shinsuke",
""
]
] | A novel method of formulating the twist-3 gluon fragmentation function contribution to hyperon polarization in the proton-proton collision is presented. The method employs a covariant gauge and takes full advantage of the Ward-Takahashi identities before performing the collinear expansion. It provides a robust way of constructing the general cross section formula, and also a clear understanding for the absence of the ghost-like terms in the twist-3 cross section in the leading order with respect to the QCD coupling constant. |
1203.4798 | Melahat Bayar | E. Oset, D. Jido, T. Sekihara, A. Martinez Torres, K. P. Khemchandani,
M. Bayar and J. Yamagata-Sekihara | A new perspective on the Faddeev equations and the $\bar{K}NN$ system
from chiral dynamics and unitarity in coupled channels | 18 pages, 7 figures, one misprint corrected, Nuclear Physics A in
press | Nucl. Phys. A 881, 127 (2012) | 10.1016/j.nuclphysa.2012.02.005 | YITP-12-24 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review recent work concerning the $\bar{K}N$ interaction and Faddeev
equations with chiral dynamics which allow us to look at the $\bar{K}NN$ from a
different perspective and pay attention to problems that have been posed in
previous studies on the subject. We show results which provide extra
experimental evidence on the existence of two $\Lambda(1405)$ states. We then
show the findings of a recent approach to Faddeev equations using chiral
unitary dynamics, where an explicit cancellation of the two body off shell
amplitude with three body forces stemming from the same chiral Lagrangians
takes place. This removal of the unphysical off shell part of the amplitudes is
most welcome and renders the approach unambiguous, showing that only on shell
two body amplitudes need to be used. With this information in mind we use an
approximation to the Faddeev equations within the fixed center approximation to
study the $\bar{K}NN$ system, providing answers within this approximation to
questions that have been brought before and evaluating binding energies and
widths of this three body system. As a novelty with respect to recent work on
the topic we find a bound state of the system with spin S=1, like a bound state
of $\bar{K}$-deuteron, less bound that the one of S=0, where all recent efforts
have been devoted. The width is relatively large in this case, suggesting
problems in a possible experimental observation.
| [
{
"created": "Wed, 21 Mar 2012 18:33:40 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Mar 2012 16:04:41 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Oset",
"E.",
""
],
[
"Jido",
"D.",
""
],
[
"Sekihara",
"T.",
""
],
[
"Torres",
"A. Martinez",
""
],
[
"Khemchandani",
"K. P.",
""
],
[
"Bayar",
"M.",
""
],
[
"Yamagata-Sekihara",
"J.",
""
]
] | We review recent work concerning the $\bar{K}N$ interaction and Faddeev equations with chiral dynamics which allow us to look at the $\bar{K}NN$ from a different perspective and pay attention to problems that have been posed in previous studies on the subject. We show results which provide extra experimental evidence on the existence of two $\Lambda(1405)$ states. We then show the findings of a recent approach to Faddeev equations using chiral unitary dynamics, where an explicit cancellation of the two body off shell amplitude with three body forces stemming from the same chiral Lagrangians takes place. This removal of the unphysical off shell part of the amplitudes is most welcome and renders the approach unambiguous, showing that only on shell two body amplitudes need to be used. With this information in mind we use an approximation to the Faddeev equations within the fixed center approximation to study the $\bar{K}NN$ system, providing answers within this approximation to questions that have been brought before and evaluating binding energies and widths of this three body system. As a novelty with respect to recent work on the topic we find a bound state of the system with spin S=1, like a bound state of $\bar{K}$-deuteron, less bound that the one of S=0, where all recent efforts have been devoted. The width is relatively large in this case, suggesting problems in a possible experimental observation. |
hep-ph/0609267 | Seung-Il Nam | Seung-il Nam and Hyun-Chul Kim | Leading-twist pion and kaon distribution amplitudes in the
gauge-invariant nonlocal chiral quark model from the instanton vacuum | 14 pages, 10 figures | Phys.Rev.D74:076005,2006 | 10.1103/PhysRevD.74.076005 | PNU-NTG-05/2006 and PNU-NURI-06/2006 | hep-ph | null | We investigate the leading-twist light-cone distribution amplitudes for the
pion and kaon based on the gauge-invariant nonlocal chiral quark model from the
instanton vacuum in the presence of external axial-vector currents. We find
that the nonlocal contribution from the gauge invariance has much effects on
the pion distribution amplitudes, while it changes mildly the kaon ones. We
also study the Gegenbauer moments of the distribution amplitudes and compare
them with the empirical analysis of the CLEO data.
| [
{
"created": "Tue, 26 Sep 2006 11:34:09 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Nam",
"Seung-il",
""
],
[
"Kim",
"Hyun-Chul",
""
]
] | We investigate the leading-twist light-cone distribution amplitudes for the pion and kaon based on the gauge-invariant nonlocal chiral quark model from the instanton vacuum in the presence of external axial-vector currents. We find that the nonlocal contribution from the gauge invariance has much effects on the pion distribution amplitudes, while it changes mildly the kaon ones. We also study the Gegenbauer moments of the distribution amplitudes and compare them with the empirical analysis of the CLEO data. |
hep-ph/9911330 | Polityko S. I. | S.Polityko, N.Takahashi, M.Kato, Y.Yamada and A.Misaki | Muon's Behaviors under Bremsstrahlung with both the LPM effect and the
Ter-Mikaelian effect and Direct Pair Production with the LPM effect | 17 pages,Latex, 32 postscript figures | Nucl.Instrum.Meth.B173:30-36,2001 | 10.1016/S0168-583X(00)00114-2 | null | hep-ph | null | Differential and integral cross sections of the muon are calculated in the
materials: water, standard rock, iron and lead with and without the LPM effect.
The corresponding cross sections are also calculated with dielectric supression
effect (Ter-Mikaelian effect), in addition to the LPM effect. To demonstrate
the importance of the LPM effect in the bremsstrahlung process, depth intensity
relation of muon, energy spectrum, range distribution and survival probability
are calculated taking into account bremsstrahlung spectrum.
| [
{
"created": "Fri, 12 Nov 1999 11:56:41 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Polityko",
"S.",
""
],
[
"Takahashi",
"N.",
""
],
[
"Kato",
"M.",
""
],
[
"Yamada",
"Y.",
""
],
[
"Misaki",
"A.",
""
]
] | Differential and integral cross sections of the muon are calculated in the materials: water, standard rock, iron and lead with and without the LPM effect. The corresponding cross sections are also calculated with dielectric supression effect (Ter-Mikaelian effect), in addition to the LPM effect. To demonstrate the importance of the LPM effect in the bremsstrahlung process, depth intensity relation of muon, energy spectrum, range distribution and survival probability are calculated taking into account bremsstrahlung spectrum. |
0908.3741 | Sushant Raut | Sushant K. Raut, Ravi Shanker Singh, S. Uma Sankar | Magical properties of 2540 Km baseline Superbeam Experiment | 14 pages, 1 figure, version published in PLB | Phys.Lett.B696:227-231,2011 | 10.1016/j.physletb.2010.12.029 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Lack of any information on the CP violating phase $\dcp$ weakens our ability
to determine neutrino mass hierarchy. Magic baseline of 7500 km was proposed to
overcome this problem. However, to obtain large enough fluxes, at this very
long baseline, one needs new techniques of generating high intensity neutrino
beams. In this letter, we highlight the {\it magical} properties of a 2540 km
baseline. At such a baseline, using a narrow band neutrino superbeam whose flux
peaks around the energy 3.5 GeV, we can determine neutrino mass hierarchy {\bf
independent} of the CP phase. For $\sin^2 2 \theta_{13} \geq 0.05$, a very
modest exposure of 10 Kiloton-years is sufficient to determine the hierarchy.
For $0.02 \leq \sin^2 2 \theta_{13} \leq 0.05$, an exposure of about 100
Kiloton-years is needed.
| [
{
"created": "Wed, 26 Aug 2009 07:21:01 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Sep 2009 12:01:04 GMT",
"version": "v2"
},
{
"created": "Wed, 2 Jun 2010 18:00:40 GMT",
"version": "v3"
},
{
"created": "Wed, 19 Jan 2011 11:10:58 GMT",
"version": "v4"
}
] | 2011-01-20 | [
[
"Raut",
"Sushant K.",
""
],
[
"Singh",
"Ravi Shanker",
""
],
[
"Sankar",
"S. Uma",
""
]
] | Lack of any information on the CP violating phase $\dcp$ weakens our ability to determine neutrino mass hierarchy. Magic baseline of 7500 km was proposed to overcome this problem. However, to obtain large enough fluxes, at this very long baseline, one needs new techniques of generating high intensity neutrino beams. In this letter, we highlight the {\it magical} properties of a 2540 km baseline. At such a baseline, using a narrow band neutrino superbeam whose flux peaks around the energy 3.5 GeV, we can determine neutrino mass hierarchy {\bf independent} of the CP phase. For $\sin^2 2 \theta_{13} \geq 0.05$, a very modest exposure of 10 Kiloton-years is sufficient to determine the hierarchy. For $0.02 \leq \sin^2 2 \theta_{13} \leq 0.05$, an exposure of about 100 Kiloton-years is needed. |
hep-ph/0402244 | Bo-Qiang Ma | Bin Wu and Bo-Qiang Ma | Exotic baryons with charm number $\pm1$ from Skyrme model | 13 pages, 2 figures. Errs in figures corrected. To appear in PRD | Phys.Rev. D70 (2004) 034025 | 10.1103/PhysRevD.70.034025 | null | hep-ph hep-ex nucl-ex nucl-th | null | We illustrate the exotic SU(3) baryon sub-multiplets in the SU(4) baryon
multiplets predicted from the flavor SU(4) collective-coordinate quantization,
and investigate the exotic states with charm number $C=\pm1$ up to leading
order of $1/N_c$ under chiral $SU(3)_L\times SU(3)_R$ symmetry and the heavy
quark limit from bound state approach. We find that there exist the
$\bar{15}$-plets and 24-plets with C=1 and the $\bar{6}$-plets, 15-plets and
$15^{\prime}$-plets with $C=-1$ bounded in this approach, qualitatively
consistent with predictions from the flavor SU(4) collective-coordinate
quantization. By fitting one unique parameter of leading SU(3) flavor symmetry
breaking term with the mass difference between $\Xi_c$ and $\Sigma_c$ and up to
$O(m_Q^0N_c^{-1})$, we give all the average masses of baryons in $\bar{6}$-plet
and 15-plet. Several general relations of these masses without any parameter
are also introduced.
| [
{
"created": "Tue, 24 Feb 2004 00:20:46 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Jun 2004 23:24:06 GMT",
"version": "v2"
},
{
"created": "Mon, 23 Aug 2004 16:03:37 GMT",
"version": "v3"
},
{
"created": "Wed, 25 Aug 2004 13:10:19 GMT",
"version": "v4"
}
] | 2009-11-10 | [
[
"Wu",
"Bin",
""
],
[
"Ma",
"Bo-Qiang",
""
]
] | We illustrate the exotic SU(3) baryon sub-multiplets in the SU(4) baryon multiplets predicted from the flavor SU(4) collective-coordinate quantization, and investigate the exotic states with charm number $C=\pm1$ up to leading order of $1/N_c$ under chiral $SU(3)_L\times SU(3)_R$ symmetry and the heavy quark limit from bound state approach. We find that there exist the $\bar{15}$-plets and 24-plets with C=1 and the $\bar{6}$-plets, 15-plets and $15^{\prime}$-plets with $C=-1$ bounded in this approach, qualitatively consistent with predictions from the flavor SU(4) collective-coordinate quantization. By fitting one unique parameter of leading SU(3) flavor symmetry breaking term with the mass difference between $\Xi_c$ and $\Sigma_c$ and up to $O(m_Q^0N_c^{-1})$, we give all the average masses of baryons in $\bar{6}$-plet and 15-plet. Several general relations of these masses without any parameter are also introduced. |
1205.1914 | Kenji Kadota | Paolo Gondolo, Junji Hisano and Kenji Kadota | The effect of quark interactions on dark matter kinetic decoupling and
the mass of the smallest dark halos | 20 pages, 4 figures, the discussion added on the scattering between
the dark matter and pions | null | 10.1103/PhysRevD.86.083523 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The kinetic decoupling of dark matter (DM) from the primordial plasma sets
the size of the first and smallest dark matter halos. Studies of the DM kinetic
decoupling have hitherto mostly neglected interactions between the DM and the
quarks in the plasma. Here we illustrate their importance using two frameworks:
a version of the Minimal Supersymmetric Standard Model (MSSM) and an effective
field theory with effective DM-quark interaction operators. We connect particle
physics and astrophysics obtaining bounds on the smallest dark matter halo size
from collider data and from direct dark matter search experiments. In the MSSM
framework, adding DM-quark interactions to DM-lepton interactions more than
doubles the smallest dark matter halo mass in a wide range of the
supersymmetric parameter space.
| [
{
"created": "Wed, 9 May 2012 08:53:38 GMT",
"version": "v1"
},
{
"created": "Thu, 29 Nov 2012 14:37:37 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Gondolo",
"Paolo",
""
],
[
"Hisano",
"Junji",
""
],
[
"Kadota",
"Kenji",
""
]
] | The kinetic decoupling of dark matter (DM) from the primordial plasma sets the size of the first and smallest dark matter halos. Studies of the DM kinetic decoupling have hitherto mostly neglected interactions between the DM and the quarks in the plasma. Here we illustrate their importance using two frameworks: a version of the Minimal Supersymmetric Standard Model (MSSM) and an effective field theory with effective DM-quark interaction operators. We connect particle physics and astrophysics obtaining bounds on the smallest dark matter halo size from collider data and from direct dark matter search experiments. In the MSSM framework, adding DM-quark interactions to DM-lepton interactions more than doubles the smallest dark matter halo mass in a wide range of the supersymmetric parameter space. |
1501.00139 | Chitta Ranjan Das | C.D. Froggatt, C.R. Das, L.V. Laperashvili and H.B. Nielsen | Diphoton decay of the Higgs boson and new bound states of top and
anti-top quarks | 27 pages and 4 figures | International Journal of Modern Physics A Vol. 30 (2015) 1550132
(28 pages) | 10.1142/S0217751X15501328 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the constraints, provided by the LHC results on Higgs boson decay
into 2 photons and its production via gluon fusion, on the previously proposed
Standard Model (SM) strongly bound state $S$ of 6 top quarks and 6 anti-top
quarks. A correlation is predicted between the ratios $\kappa_{\gamma}$ and
$\kappa_g$ of the Higgs diphoton decay and gluon production amplitudes
respectively to their SM values. We estimate the contribution to these
amplitudes from one loop diagrams involving the 12 quark bound state $S$ and
related excited states using an atomic physics based model. We find two regions
of parameter space consistent with the ATLAS and CMS data on
($\kappa_{\gamma}$, $\kappa_g$) at the 3 sigma level: a region close to the SM
values ($\kappa_{\gamma}=1$, $\kappa_g =1$) with the mass of the bound state
$m_S > 400$ GeV and a region with ($\kappa_{\gamma} \sim 3/2$, $\kappa_g \sim
-3/4$) corresponding to a bound state mass of $m_S \sim 220$ GeV.
| [
{
"created": "Wed, 31 Dec 2014 14:08:38 GMT",
"version": "v1"
}
] | 2015-07-17 | [
[
"Froggatt",
"C. D.",
""
],
[
"Das",
"C. R.",
""
],
[
"Laperashvili",
"L. V.",
""
],
[
"Nielsen",
"H. B.",
""
]
] | We consider the constraints, provided by the LHC results on Higgs boson decay into 2 photons and its production via gluon fusion, on the previously proposed Standard Model (SM) strongly bound state $S$ of 6 top quarks and 6 anti-top quarks. A correlation is predicted between the ratios $\kappa_{\gamma}$ and $\kappa_g$ of the Higgs diphoton decay and gluon production amplitudes respectively to their SM values. We estimate the contribution to these amplitudes from one loop diagrams involving the 12 quark bound state $S$ and related excited states using an atomic physics based model. We find two regions of parameter space consistent with the ATLAS and CMS data on ($\kappa_{\gamma}$, $\kappa_g$) at the 3 sigma level: a region close to the SM values ($\kappa_{\gamma}=1$, $\kappa_g =1$) with the mass of the bound state $m_S > 400$ GeV and a region with ($\kappa_{\gamma} \sim 3/2$, $\kappa_g \sim -3/4$) corresponding to a bound state mass of $m_S \sim 220$ GeV. |
2305.09831 | Craig Roberts | Pei-Lin Yin, Chen Chen, Christian S. Fischer and Craig D. Roberts | $\Delta$-baryon axialvector and pseudoscalar form factors, and
associated PCAC relations | 19 pages, 9 figures, 2 tables | null | 10.1140/epja/s10050-023-01066-9 | USTC-ICTS/PCFT-23-14, NJU-INP 074/23 | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A quark+diquark Faddeev equation treatment of the baryon bound state problem
in Poincar\'e-invariant quantum field theory is used to deliver parameter-free
predictions for all six $\Delta$-baryon elastic weak form factors. Amongst the
results, it is worth highlighting that there are two distinct classes of such
$\Delta$-baryon form factors, $(g_1, g_3, G_{\pi\Delta\Delta})$, $(h_1, h_3,
H_{\pi\Delta\Delta})$, the functions within each of which are separately linked
via partial conservation of axial current (PCAC) and Goldberger-Treiman (GT)
relations. Respectively within each class, the listed form factors possess
qualitatively the same structural features as the nucleon axial, induced
pseudoscalar, and pion-nucleon coupling form factors. For instance, the
$\Delta$-baryon $g_1$ axial form factor can reliably be approximated by a
dipole function, characterised by an axial charge $g_A^{\Delta^+}=0.71(9)$ and
mass-scale $m_A^\Delta=0.95(2)m_\Delta$. Moreover, the two distinct
$\Delta$-baryon PCAC form factor relations are satisfied to a high degree of
accuracy on a large range of $Q^2$; the associated GT relations present good
approximations only on $Q^2/m_\Delta^2 \simeq 0$; and pion pole dominance
approximations are reliable within both classes. There are two
$\pi\Delta\Delta$ couplings: $g_{\pi\Delta\Delta} = 10.46(1.88)$;
$h_{\pi\Delta\Delta}= 35.73(3.75)$; and the associated form factors are soft.
Such couplings commonly arise in phenomenology, which may therefore benefit
from our analyses. A flavour decomposition of the axial charges reveals that
quarks carry $71$\% of the $\Delta$-baryon spin. The analogous result for the
proton is $\approx 65$\%.
| [
{
"created": "Tue, 16 May 2023 22:15:29 GMT",
"version": "v1"
}
] | 2023-08-02 | [
[
"Yin",
"Pei-Lin",
""
],
[
"Chen",
"Chen",
""
],
[
"Fischer",
"Christian S.",
""
],
[
"Roberts",
"Craig D.",
""
]
] | A quark+diquark Faddeev equation treatment of the baryon bound state problem in Poincar\'e-invariant quantum field theory is used to deliver parameter-free predictions for all six $\Delta$-baryon elastic weak form factors. Amongst the results, it is worth highlighting that there are two distinct classes of such $\Delta$-baryon form factors, $(g_1, g_3, G_{\pi\Delta\Delta})$, $(h_1, h_3, H_{\pi\Delta\Delta})$, the functions within each of which are separately linked via partial conservation of axial current (PCAC) and Goldberger-Treiman (GT) relations. Respectively within each class, the listed form factors possess qualitatively the same structural features as the nucleon axial, induced pseudoscalar, and pion-nucleon coupling form factors. For instance, the $\Delta$-baryon $g_1$ axial form factor can reliably be approximated by a dipole function, characterised by an axial charge $g_A^{\Delta^+}=0.71(9)$ and mass-scale $m_A^\Delta=0.95(2)m_\Delta$. Moreover, the two distinct $\Delta$-baryon PCAC form factor relations are satisfied to a high degree of accuracy on a large range of $Q^2$; the associated GT relations present good approximations only on $Q^2/m_\Delta^2 \simeq 0$; and pion pole dominance approximations are reliable within both classes. There are two $\pi\Delta\Delta$ couplings: $g_{\pi\Delta\Delta} = 10.46(1.88)$; $h_{\pi\Delta\Delta}= 35.73(3.75)$; and the associated form factors are soft. Such couplings commonly arise in phenomenology, which may therefore benefit from our analyses. A flavour decomposition of the axial charges reveals that quarks carry $71$\% of the $\Delta$-baryon spin. The analogous result for the proton is $\approx 65$\%. |
hep-ph/9910446 | Bernd-Jochen Schaefer | B.-J. Schaefer, O. Bohr and J. Wambach | Flow Equations and the Chiral Phase Transition | LaTeX file, 6 pages, 4 ps figures included with psfig.sty and
sprocl.sty. Proceeding of the "XVII Autumn School: QCD - perturbative or
nonperturbative?", Lisbon, Portugal, Sept.-Oct. 1999 | null | null | null | hep-ph | null | Flow equations for an O(N)-symmetric effective potential are discussed and
solved for the finite temperature case. The model is investigated at the
critical point and critical exponents for various N are calculated.
| [
{
"created": "Fri, 22 Oct 1999 14:54:19 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Schaefer",
"B. -J.",
""
],
[
"Bohr",
"O.",
""
],
[
"Wambach",
"J.",
""
]
] | Flow equations for an O(N)-symmetric effective potential are discussed and solved for the finite temperature case. The model is investigated at the critical point and critical exponents for various N are calculated. |
1804.10289 | Michal Iglicki | Michal Iglicki | Vector-fermion dark matter | 56 pages, 23 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this thesis a simple extension of the Standard Model has been
investigated. The Standard Model gauge group has been extended by an additional
$U(1)_X$ group. The model introduces a new Higgs particle as well as three
particles (a gauge boson and two Majorana fermions) that can be candidates for
dark matter. The thesis also contains a discussion of derivation of the
Boltzmann equation, involving detailed analysis of the assumptions. The
equation has been used to investigate behaviour of the dark matter density in
time, with respect to values of the parameters of the model.
| [
{
"created": "Thu, 26 Apr 2018 21:46:02 GMT",
"version": "v1"
}
] | 2018-04-30 | [
[
"Iglicki",
"Michal",
""
]
] | In this thesis a simple extension of the Standard Model has been investigated. The Standard Model gauge group has been extended by an additional $U(1)_X$ group. The model introduces a new Higgs particle as well as three particles (a gauge boson and two Majorana fermions) that can be candidates for dark matter. The thesis also contains a discussion of derivation of the Boltzmann equation, involving detailed analysis of the assumptions. The equation has been used to investigate behaviour of the dark matter density in time, with respect to values of the parameters of the model. |
1512.06135 | Admir Greljo | Admir Greljo, Gino Isidori, Jonas M. Lindert, David Marzocca | Pseudo-observables in electroweak Higgs production | 34 pages, 12 figures, 1 table | null | 10.1140/epjc/s10052-016-4000-5 | ZU-TH-47/15 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss how the leading electroweak Higgs production processes at the LHC,
namely vector-boson fusion and Higgs+W/Z associated production, can be
characterized in generic extensions of the Standard Model by a proper set of
pseudo-observables (PO). We analyze the symmetry properties of these PO and
their relation with the PO set appearing in Higgs decays. We discuss in detail
the kinematical studies necessary to extract the production PO from data, and
present a first estimate of the LHC sensitivity on these observables in the
high-luminosity phase. The impact of QCD corrections and the kinematical
studies necessary to test the validity of the momentum expansion at the basis
of the PO decomposition are also discussed.
| [
{
"created": "Fri, 18 Dec 2015 21:03:21 GMT",
"version": "v1"
}
] | 2016-04-20 | [
[
"Greljo",
"Admir",
""
],
[
"Isidori",
"Gino",
""
],
[
"Lindert",
"Jonas M.",
""
],
[
"Marzocca",
"David",
""
]
] | We discuss how the leading electroweak Higgs production processes at the LHC, namely vector-boson fusion and Higgs+W/Z associated production, can be characterized in generic extensions of the Standard Model by a proper set of pseudo-observables (PO). We analyze the symmetry properties of these PO and their relation with the PO set appearing in Higgs decays. We discuss in detail the kinematical studies necessary to extract the production PO from data, and present a first estimate of the LHC sensitivity on these observables in the high-luminosity phase. The impact of QCD corrections and the kinematical studies necessary to test the validity of the momentum expansion at the basis of the PO decomposition are also discussed. |
hep-ph/0109004 | James Wells | Hitoshi Murayama and James D. Wells | Graviton emission from a soft brane | 4 pages, Revtex | Phys.Rev.D65:056011,2002 | 10.1103/PhysRevD.65.056011 | LBNL-48867 | hep-ph | null | Theories with compact extra spatial dimensions felt only by gravity are
subject to direct experimental tests if the compactification volume is large.
Estimates of high-energy collider observables induced by graviton radiation
into extra dimensions are usually given assuming rigid branes. This may
overestimate the accessibility of these theories. Brane fluctuations soften the
coupling of graviton radiation, and reduce our ability to see effects in
high-energy collisions. We calculate the size of this suppression on single jet
plus gravitons at the LHC and single photon plus gravitons at an e+e- linear
collider. We advocate the use of a brane softening variable as an additional
parameter when comparing theory predictions to data.
| [
{
"created": "Sun, 2 Sep 2001 04:33:12 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Murayama",
"Hitoshi",
""
],
[
"Wells",
"James D.",
""
]
] | Theories with compact extra spatial dimensions felt only by gravity are subject to direct experimental tests if the compactification volume is large. Estimates of high-energy collider observables induced by graviton radiation into extra dimensions are usually given assuming rigid branes. This may overestimate the accessibility of these theories. Brane fluctuations soften the coupling of graviton radiation, and reduce our ability to see effects in high-energy collisions. We calculate the size of this suppression on single jet plus gravitons at the LHC and single photon plus gravitons at an e+e- linear collider. We advocate the use of a brane softening variable as an additional parameter when comparing theory predictions to data. |
hep-ph/9810250 | Afanasyev Leonid | L.Afanasyev, A.Tarasov and O.Voskresenskaya | Sum Rules for Total Interaction Cross Sections of Relativistic
Elementary Atoms with Atoms of Matter Up to Terms of Order $\alpha^2$ | 3 pages | null | null | null | hep-ph | null | It is shown that $\alpha^2$-term of sum rules for the total cross sections of
interaction of elementary atoms with matter ones, obtained in ref.[Denisenko K.
and Mrowczynski S., Phys. Rev. D36 (1987) 1529] is wrong. New sum rules valid
up to terms of order $\alpha^2$ are derived.
| [
{
"created": "Mon, 5 Oct 1998 14:27:50 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Afanasyev",
"L.",
""
],
[
"Tarasov",
"A.",
""
],
[
"Voskresenskaya",
"O.",
""
]
] | It is shown that $\alpha^2$-term of sum rules for the total cross sections of interaction of elementary atoms with matter ones, obtained in ref.[Denisenko K. and Mrowczynski S., Phys. Rev. D36 (1987) 1529] is wrong. New sum rules valid up to terms of order $\alpha^2$ are derived. |
2405.09629 | Ayodele Ore | Luigi Favaro, Ayodele Ore, Sofia Palacios Schweitzer and Tilman Plehn | CaloDREAM -- Detector Response Emulation via Attentive flow Matching | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Detector simulations are an exciting application of modern generative
networks. Their sparse high-dimensional data combined with the required
precision poses a serious challenge. We show how combining Conditional Flow
Matching with transformer elements allows us to simulate the detector phase
space reliably. Namely, we use an autoregressive transformer to simulate the
energy of each layer, and a vision transformer for the high-dimensional voxel
distributions. We show how dimension reduction via latent diffusion allows us
to train more efficiently and how diffusion networks can be evaluated faster
with bespoke solvers. We showcase our framework, CaloDREAM, on datasets 2 and 3
of the CaloChallenge.
| [
{
"created": "Wed, 15 May 2024 18:00:36 GMT",
"version": "v1"
},
{
"created": "Fri, 17 May 2024 07:31:33 GMT",
"version": "v2"
}
] | 2024-05-20 | [
[
"Favaro",
"Luigi",
""
],
[
"Ore",
"Ayodele",
""
],
[
"Schweitzer",
"Sofia Palacios",
""
],
[
"Plehn",
"Tilman",
""
]
] | Detector simulations are an exciting application of modern generative networks. Their sparse high-dimensional data combined with the required precision poses a serious challenge. We show how combining Conditional Flow Matching with transformer elements allows us to simulate the detector phase space reliably. Namely, we use an autoregressive transformer to simulate the energy of each layer, and a vision transformer for the high-dimensional voxel distributions. We show how dimension reduction via latent diffusion allows us to train more efficiently and how diffusion networks can be evaluated faster with bespoke solvers. We showcase our framework, CaloDREAM, on datasets 2 and 3 of the CaloChallenge. |
1301.2345 | Tim Stefaniak | Philip Bechtle, Oliver Brein, Sven Heinemeyer, Oscar St{\aa}l, Tim
Stefaniak, Georg Weiglein, Karina Williams | Recent Developments in HiggsBounds and a Preview of HiggsSignals | 6 pages, 3 figures; Proceedings of "Prospects for Charged Higgs
Discovery at Colliders", October 2012, Uppsala, Sweden | null | null | BONN-TH-2013-01, DESY 13-004 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on recent developments in the public computer code HiggsBounds,
which confronts arbitrary Higgs sector predictions with 95% C.L. exclusion
limits from Higgs searches at the LEP, Tevatron and LHC experiments. We discuss
in detail the performance of the Standard Model (SM) likeness test as
implemented in the latest version HiggsBounds-3.8.0, whose outcome decides
whether a search for a SM Higgs boson can be applied to a model beyond the SM.
Furthermore, we give a preview of features in the upcoming version
HiggsBounds-4.0.0 and the new program HiggsSignals, which performs a
chi-squared test of Higgs sector predictions against the signal rate and mass
measurements from Higgs boson analyses at the Tevatron and LHC. This is
illustrated with an example where the heavier CP-even Higgs boson of the
Minimal Supersymmetric Standard Model (MSSM) is considered as an explanation of
the LHC Higgs signal at ~126 GeV.
| [
{
"created": "Thu, 10 Jan 2013 22:01:11 GMT",
"version": "v1"
}
] | 2013-01-14 | [
[
"Bechtle",
"Philip",
""
],
[
"Brein",
"Oliver",
""
],
[
"Heinemeyer",
"Sven",
""
],
[
"Stål",
"Oscar",
""
],
[
"Stefaniak",
"Tim",
""
],
[
"Weiglein",
"Georg",
""
],
[
"Williams",
"Karina",
""
]
] | We report on recent developments in the public computer code HiggsBounds, which confronts arbitrary Higgs sector predictions with 95% C.L. exclusion limits from Higgs searches at the LEP, Tevatron and LHC experiments. We discuss in detail the performance of the Standard Model (SM) likeness test as implemented in the latest version HiggsBounds-3.8.0, whose outcome decides whether a search for a SM Higgs boson can be applied to a model beyond the SM. Furthermore, we give a preview of features in the upcoming version HiggsBounds-4.0.0 and the new program HiggsSignals, which performs a chi-squared test of Higgs sector predictions against the signal rate and mass measurements from Higgs boson analyses at the Tevatron and LHC. This is illustrated with an example where the heavier CP-even Higgs boson of the Minimal Supersymmetric Standard Model (MSSM) is considered as an explanation of the LHC Higgs signal at ~126 GeV. |
hep-ph/0407167 | Andrei Afanasev | Andrei Afanasev, N.P. Merenkov | Collinear Photon Exchange in the Beam Normal Polarization Asymmetry of
Elastic Electron-Proton Scattering | 6 pages, 5 figures, Corrected an algebraic error in Eq.(17), other
formulas and plots changed accordingly | Phys.Lett.B599:48,2004 | 10.1016/j.physletb.2004.08.023 | null | hep-ph | null | The parity-conserving single-spin beam asymmetry of elastic electron-proton
scattering is induced by an absorptive part of the two-photon exchange
amplitude. We demonstrate that this asymmetry has logarithmic and
double-logarithmic enhancement due to contributions of hard collinear
quasi-real photons. An optical theorem is used to evaluate the asymmetry in
terms of the total photoproduction cross section on the proton, predicting its
magnitude at a few parts per million for high electon beam energies and small
scattering angles. At fixed 4-momentum transfers, the asymmetry is rising
logarithmically with increasing electron beam energy, following the high-energy
diffractive behavior of total photoproduction cross section on the proton.
| [
{
"created": "Thu, 15 Jul 2004 02:15:48 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Oct 2005 06:33:52 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Afanasev",
"Andrei",
""
],
[
"Merenkov",
"N. P.",
""
]
] | The parity-conserving single-spin beam asymmetry of elastic electron-proton scattering is induced by an absorptive part of the two-photon exchange amplitude. We demonstrate that this asymmetry has logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. An optical theorem is used to evaluate the asymmetry in terms of the total photoproduction cross section on the proton, predicting its magnitude at a few parts per million for high electon beam energies and small scattering angles. At fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton. |
2006.14739 | Elena Bratkovskaya | V. Kireyeu, I. Grishmanovskii, V. Kolesnikov, V. Voronyuk, and E.
Bratkovskaya | Hadron production in elementary nucleon-nucleon reactions from low to
ultra-relativistic energies | 18 pages, 17 figures; extended version to be published in the
European Physical Journal A | null | null | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the hadron production in $p+p$, $p+n$ and $n+n$ reactions within the
microscopic Parton-Hadron-Dynamics (PHSD) transport approach in comparison to
PYTHIA 8.2. We discuss the details of the "PHSD tune" of the Lund string model
(realized by event generators FRITIOF and PYTHIA) in the vacuum (as in $N+N$
collisions) as well as its in-medium modifications relevant for heavy-ion
collisions where a hot and dense matter is produced. We compare the results of
PHSD and PYTHIA 8.2 (default version) for the excitation function of hadron
multiplicities as well as differential rapidity $y$, transverse momentum $p_T$
and $x_F$ distributions in $p+p$, $p+n$ and $n+n$ reactions with the existing
experimental data in the energy range $\sqrt{s_{NN}} = 2.7 - 7000$ GeV. We
discuss the production mechanisms of hadrons and the role of final state
interactions (FSI) due to the hadronic rescattering. We also show the influence
of the possible quark-gluon plasma (QGP) formation on hadronic observables in
$p+p$ collisions at LHC energies. We stress the importance of developing a
reliable event generator for elementary reactions from low to
ultra-relativistic energies in view of actual and upcoming heavy-ion
experiments.
| [
{
"created": "Fri, 26 Jun 2020 00:44:52 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Aug 2020 00:23:47 GMT",
"version": "v2"
}
] | 2020-08-26 | [
[
"Kireyeu",
"V.",
""
],
[
"Grishmanovskii",
"I.",
""
],
[
"Kolesnikov",
"V.",
""
],
[
"Voronyuk",
"V.",
""
],
[
"Bratkovskaya",
"E.",
""
]
] | We study the hadron production in $p+p$, $p+n$ and $n+n$ reactions within the microscopic Parton-Hadron-Dynamics (PHSD) transport approach in comparison to PYTHIA 8.2. We discuss the details of the "PHSD tune" of the Lund string model (realized by event generators FRITIOF and PYTHIA) in the vacuum (as in $N+N$ collisions) as well as its in-medium modifications relevant for heavy-ion collisions where a hot and dense matter is produced. We compare the results of PHSD and PYTHIA 8.2 (default version) for the excitation function of hadron multiplicities as well as differential rapidity $y$, transverse momentum $p_T$ and $x_F$ distributions in $p+p$, $p+n$ and $n+n$ reactions with the existing experimental data in the energy range $\sqrt{s_{NN}} = 2.7 - 7000$ GeV. We discuss the production mechanisms of hadrons and the role of final state interactions (FSI) due to the hadronic rescattering. We also show the influence of the possible quark-gluon plasma (QGP) formation on hadronic observables in $p+p$ collisions at LHC energies. We stress the importance of developing a reliable event generator for elementary reactions from low to ultra-relativistic energies in view of actual and upcoming heavy-ion experiments. |
2203.03278 | Anton Sokolov Vladimirovich | Anton V. Sokolov | Duality Symmetric Electrodynamics in Curved Spacetime | 7 pages; general-covariant duality symmetric theory is constructed | null | null | DESY 22-039 | hep-ph gr-qc hep-ex hep-th | http://creativecommons.org/licenses/by/4.0/ | We derive Maxwell equations for electric and magnetic fields in curved
spacetime from first principles, relaxing an unnecessary assumption on the
structure of the four-potential inherent to the standard approach and thus
restoring the full consistency with the equivalence principle in the following
two important cases: first, if the electromagnetic field is considered as a
physical entity separate from the charged particles used to measure it, and
second, if hypothetical magnetically charged particles are allowed to exist. We
find that in a generic curved spacetime, the electromagnetic field has to be
described by two pairs of electric and magnetic fields, instead of the only one
pair which is enough in the flat spacetime case.
| [
{
"created": "Mon, 7 Mar 2022 10:50:17 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Mar 2022 17:37:56 GMT",
"version": "v2"
},
{
"created": "Thu, 5 May 2022 12:18:49 GMT",
"version": "v3"
},
{
"created": "Thu, 12 Oct 2023 17:45:01 GMT",
"version": "v4"
}
] | 2023-10-13 | [
[
"Sokolov",
"Anton V.",
""
]
] | We derive Maxwell equations for electric and magnetic fields in curved spacetime from first principles, relaxing an unnecessary assumption on the structure of the four-potential inherent to the standard approach and thus restoring the full consistency with the equivalence principle in the following two important cases: first, if the electromagnetic field is considered as a physical entity separate from the charged particles used to measure it, and second, if hypothetical magnetically charged particles are allowed to exist. We find that in a generic curved spacetime, the electromagnetic field has to be described by two pairs of electric and magnetic fields, instead of the only one pair which is enough in the flat spacetime case. |
0809.3264 | Mariangela Lisanti | Johan Alwall, My-Phuong Le, Mariangela Lisanti and Jay G. Wacker | Model-Independent Jets plus Missing Energy Searches | 22 pages, 6 figures, 3 tables, typos corrected | Phys.Rev.D79:015005,2009 | 10.1103/PhysRevD.79.015005 | SLAC-PUB-13405 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a proposal for performing model-independent jets plus missing
energy searches. Currently, these searches are optimized for mSUGRA and are
consequently not sensitive to all kinematically-accessible regions of parameter
space. We show that the reach of these searches can be broadened by setting
limits on the differential cross section as a function of the total visible
energy and the missing energy. These measurements only require knowledge of the
relevant Standard Model backgrounds and can be subsequently used to limit any
theoretical model of new physics. We apply this approach to an example where
gluinos are pair-produced and decay to the LSP through a single-step cascade,
and show how sensitivity to different gluino masses is altered by the presence
of the decay chain. The analysis is closely based upon the current searches
done at the Tevatron and our proposal requires only small modifications to the
existing techniques. We find that within the MSSM, the gluino can be as light
as 125 GeV. The same techniques are applicable to jets and missing energy
searches at the Large Hadron Collider.
| [
{
"created": "Thu, 18 Sep 2008 22:14:11 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Dec 2008 19:55:22 GMT",
"version": "v2"
}
] | 2009-02-23 | [
[
"Alwall",
"Johan",
""
],
[
"Le",
"My-Phuong",
""
],
[
"Lisanti",
"Mariangela",
""
],
[
"Wacker",
"Jay G.",
""
]
] | We present a proposal for performing model-independent jets plus missing energy searches. Currently, these searches are optimized for mSUGRA and are consequently not sensitive to all kinematically-accessible regions of parameter space. We show that the reach of these searches can be broadened by setting limits on the differential cross section as a function of the total visible energy and the missing energy. These measurements only require knowledge of the relevant Standard Model backgrounds and can be subsequently used to limit any theoretical model of new physics. We apply this approach to an example where gluinos are pair-produced and decay to the LSP through a single-step cascade, and show how sensitivity to different gluino masses is altered by the presence of the decay chain. The analysis is closely based upon the current searches done at the Tevatron and our proposal requires only small modifications to the existing techniques. We find that within the MSSM, the gluino can be as light as 125 GeV. The same techniques are applicable to jets and missing energy searches at the Large Hadron Collider. |
1312.4407 | Saeede Nafooshe | Saeede Nafooshe, Martin O'Loughlin, Maria Vittoria Garzelli | Micro Black Hole Production and Evaporation | 8 pages, 3 figures, oral contribution at the 4th International
Conference on Time And Matter - TAM 2013, Venice, Italy, 4 - 8 March, 2013 | Proceedings of the 4th Conference on Time and Matter - TAM 2013,
pp 175 - 181, UNG press (ISBN 978-961-6311-79-3) | null | null | hep-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It has been conjectured that Micro Black Holes (MBH) may be formed in the
presence of large extra dimensions. These MBHs have very small mass and they
decay almost instantaneously. Taking into consideration quantum effects, they
should Hawking radiate mainly to Standard Model particles, this radiation then
gets modified by the non trivial geometry around the MBHs; the so called
greybody factors which filter the Hawking radiation. To test the validity of
MBH models, one needs to investigate it experimentally. A primary tool in this
investigation is simulation of the MBH formation and evaporation, including all
theoretical work that has been performed up to now. BlackMax and CHARYBDIS2 are
the most modern and realistic simulators currently available. However they
still suffer from a lack of important parameters. In this article we will
discuss the primary work that we have done to study the possible changes that
can be implemented in the simulations.
| [
{
"created": "Mon, 16 Dec 2013 15:44:38 GMT",
"version": "v1"
}
] | 2013-12-17 | [
[
"Nafooshe",
"Saeede",
""
],
[
"O'Loughlin",
"Martin",
""
],
[
"Garzelli",
"Maria Vittoria",
""
]
] | It has been conjectured that Micro Black Holes (MBH) may be formed in the presence of large extra dimensions. These MBHs have very small mass and they decay almost instantaneously. Taking into consideration quantum effects, they should Hawking radiate mainly to Standard Model particles, this radiation then gets modified by the non trivial geometry around the MBHs; the so called greybody factors which filter the Hawking radiation. To test the validity of MBH models, one needs to investigate it experimentally. A primary tool in this investigation is simulation of the MBH formation and evaporation, including all theoretical work that has been performed up to now. BlackMax and CHARYBDIS2 are the most modern and realistic simulators currently available. However they still suffer from a lack of important parameters. In this article we will discuss the primary work that we have done to study the possible changes that can be implemented in the simulations. |
1011.1111 | Tom\'a\v{s} Brauner | Tomas Brauner | Phase diagram of dense quark matter in QCD-like theories | 3 pages, 1 pdf figure; talk at the conference "Quark Confinement and
the Hadron Spectrum IX", Madrid, August 30-September 3, 2010 | AIP Conf.Proc.1343:589-591,2011 | 10.1063/1.3575103 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I report the results of a series of works on the phase diagram of theories
with a different number of colors and/or quarks in a different representation
than in QCD. Similarities as well as differences as compared to the real world
are pointed out, focusing in particular on the interplay of confinement and
chiral symmetry breaking. It will be argued that recent lattice data may
provide us with a clue to understand deconfinement in cold dense quark matter.
| [
{
"created": "Thu, 4 Nov 2010 10:59:10 GMT",
"version": "v1"
}
] | 2011-06-15 | [
[
"Brauner",
"Tomas",
""
]
] | I report the results of a series of works on the phase diagram of theories with a different number of colors and/or quarks in a different representation than in QCD. Similarities as well as differences as compared to the real world are pointed out, focusing in particular on the interplay of confinement and chiral symmetry breaking. It will be argued that recent lattice data may provide us with a clue to understand deconfinement in cold dense quark matter. |
2103.11091 | Li Liang | Liang Li | Standard GRB Spectral Models "Misused"? | 38 pages, 12 figures (including 263 panels),2 tables, ApJ in press | null | 10.3847/1538-4357/ac3d89 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The standard model characterizing the gamma-ray burst (GRB) spectrum invokes
a four-parameter empirical function, the so-called the BAND model. An
alternative model named cutoff power law (COMP) implements a power law with an
exponential cutoff. These functions achieve almost equally good fits on
observed spectra, and are adopted in nearly all of the GRB literature. Here, we
reanalyze the sample defined in Li.et al.,2021,ApJS,254,35 (39 bursts including
944 spectra). We classify the spectra by two methods: (1) checking their
corner-corner plots of the posteriors to determine well-constrained $\beta$
(BAND-better) and unconstrained $\beta$ (COMP-better) categories; and (2)
defining the four groups by difference of the deviance information criterion
(DIC). We find inconsistent peaks of the parameter distributions between the
BAND-better spectra ($\alpha=-0.64\pm0.28$ and $\rm log_{10}(E_{\rm p})=\rm
log_{10}(191)\pm0.41$) and the COMP-better spectra ($\alpha=-0.96\pm0.33$ and
$\rm log_{10}(E_{\rm p})=\rm log_{10}(249)\pm0.40$). With the statistically
preferred model and vice versa the misused model defined based on DIC
statistics, we also find that the fitted parameters obtained by the misused
model (COMP) significantly deviate from those obtained by the statistically
preferred model (BAND). This means that if a spectrum is statistically
preferred, described as the BAND, applying COMP to derive the spectral
parameters will prominently deviate from their intrinsic shape, therefore
affecting the physical interpretation. Our analysis indicates that the better
or statistically preferred model should be duly examined during GRB spectral
analysis. In addition, the $\beta$ distribution exhibits a bimodal structure
containing the BAND-better and COMP-better spectra, respectively, implying that
BAND and COMP both may have physical origin.
| [
{
"created": "Sat, 20 Mar 2021 04:23:15 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Mar 2022 17:00:42 GMT",
"version": "v2"
}
] | 2022-12-21 | [
[
"Li",
"Liang",
""
]
] | The standard model characterizing the gamma-ray burst (GRB) spectrum invokes a four-parameter empirical function, the so-called the BAND model. An alternative model named cutoff power law (COMP) implements a power law with an exponential cutoff. These functions achieve almost equally good fits on observed spectra, and are adopted in nearly all of the GRB literature. Here, we reanalyze the sample defined in Li.et al.,2021,ApJS,254,35 (39 bursts including 944 spectra). We classify the spectra by two methods: (1) checking their corner-corner plots of the posteriors to determine well-constrained $\beta$ (BAND-better) and unconstrained $\beta$ (COMP-better) categories; and (2) defining the four groups by difference of the deviance information criterion (DIC). We find inconsistent peaks of the parameter distributions between the BAND-better spectra ($\alpha=-0.64\pm0.28$ and $\rm log_{10}(E_{\rm p})=\rm log_{10}(191)\pm0.41$) and the COMP-better spectra ($\alpha=-0.96\pm0.33$ and $\rm log_{10}(E_{\rm p})=\rm log_{10}(249)\pm0.40$). With the statistically preferred model and vice versa the misused model defined based on DIC statistics, we also find that the fitted parameters obtained by the misused model (COMP) significantly deviate from those obtained by the statistically preferred model (BAND). This means that if a spectrum is statistically preferred, described as the BAND, applying COMP to derive the spectral parameters will prominently deviate from their intrinsic shape, therefore affecting the physical interpretation. Our analysis indicates that the better or statistically preferred model should be duly examined during GRB spectral analysis. In addition, the $\beta$ distribution exhibits a bimodal structure containing the BAND-better and COMP-better spectra, respectively, implying that BAND and COMP both may have physical origin. |
1512.01316 | Kiminad Mamo | Kiminad A. Mamo, Ho-Ung Yee | Spin Polarized Photons from Axially Charged Plasma at Weak Coupling:
Complete Leading Order | 41 pages, 11 figures; v2: one minor typo fixed, references added,
accepted for publication in PRD | Phys. Rev. D 93, 065053 (2016) | 10.1103/PhysRevD.93.065053 | RBRC-1158 | hep-ph hep-th nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the presence of (approximately conserved) axial charge in the QCD plasma
at finite temperature, the emitted photons are spin-aligned, which is a unique
P- and CP-odd signature of axial charge in the photon emission observables. We
compute this "P-odd photon emission rate" in weak coupling regime at high
temperature limit to complete leading order in the QCD coupling constant: the
leading log as well as the constant under the log. As in the P-even total
emission rate in the literature, the computation of P-odd emission rate at
leading order consists of three parts: 1) Compton and Pair Annihilation
processes with hard momentum exchange, 2) soft t- and u-channel contributions
with Hard Thermal Loop re-summation, 3) Landau-Pomeranchuk-Migdal (LPM)
re-summation of collinear Bremstrahlung and Pair Annihilation. We present
analytical and numerical evaluations of these contributions to our P-odd photon
emission rate observable.
| [
{
"created": "Fri, 4 Dec 2015 04:48:08 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Dec 2015 06:18:41 GMT",
"version": "v2"
},
{
"created": "Mon, 11 Apr 2016 02:53:58 GMT",
"version": "v3"
}
] | 2016-04-12 | [
[
"Mamo",
"Kiminad A.",
""
],
[
"Yee",
"Ho-Ung",
""
]
] | In the presence of (approximately conserved) axial charge in the QCD plasma at finite temperature, the emitted photons are spin-aligned, which is a unique P- and CP-odd signature of axial charge in the photon emission observables. We compute this "P-odd photon emission rate" in weak coupling regime at high temperature limit to complete leading order in the QCD coupling constant: the leading log as well as the constant under the log. As in the P-even total emission rate in the literature, the computation of P-odd emission rate at leading order consists of three parts: 1) Compton and Pair Annihilation processes with hard momentum exchange, 2) soft t- and u-channel contributions with Hard Thermal Loop re-summation, 3) Landau-Pomeranchuk-Migdal (LPM) re-summation of collinear Bremstrahlung and Pair Annihilation. We present analytical and numerical evaluations of these contributions to our P-odd photon emission rate observable. |
1908.04622 | Kai-Lei Wang | Kai-Lei Wang, Qi-Fang L\"u, and Xian-Hui Zhong | Interpretation of the newly observed $\Lambda_b(6146)^{0}$ and
$\Lambda_b(6152)^0$ states in a chiral quark model | 6 pages. arXiv admin note: text overlap with arXiv:1810.02205 | Phys. Rev. D 100, 114035 (2019) | 10.1103/PhysRevD.100.114035 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The strong decays of the low-lying $\lambda$-mode $\Lambda_b(1D,2S)$ and
$\Sigma_b(2S)$ states are studied in a chiral quark model. We find that: (i)
the newly observed $\Lambda_b(6146/6152)$ resonances in the
$\Lambda_b\pi^+\pi^-$ spectrum by the LHCb Collaboration might be explained
with the $\lambda$-mode $\Lambda_b(1D)$ states in the quark model. It should be
emphasized that whether the structure in the $\Lambda_b\pi^+\pi^-$ spectrum
correspond to two states or one state should be further clarified with more
observations in future experiments. (ii) The $\Lambda_b(2S)$ $|J^P =
\frac{1}{2}^+,0\rangle$ state mainly decays into $\Sigma_b^*\pi$ channel, which
may be an ideal channel for searching for this $\Lambda_b(2S)$ state in future
experiments. (iii) The $\Sigma_b(2S)$ $|J^P = \frac{1}{2}^+,1 \rangle$ and
$|J^P = \frac{3}{2}^+,1 \rangle$ dominantly decay into $\Lambda_b\pi$ with
$\Gamma \simeq 3.82$ MeV and $\Gamma \simeq 4.72$ MeV, respectively.
| [
{
"created": "Tue, 13 Aug 2019 13:06:46 GMT",
"version": "v1"
},
{
"created": "Thu, 29 Aug 2019 07:41:05 GMT",
"version": "v2"
}
] | 2020-01-01 | [
[
"Wang",
"Kai-Lei",
""
],
[
"Lü",
"Qi-Fang",
""
],
[
"Zhong",
"Xian-Hui",
""
]
] | The strong decays of the low-lying $\lambda$-mode $\Lambda_b(1D,2S)$ and $\Sigma_b(2S)$ states are studied in a chiral quark model. We find that: (i) the newly observed $\Lambda_b(6146/6152)$ resonances in the $\Lambda_b\pi^+\pi^-$ spectrum by the LHCb Collaboration might be explained with the $\lambda$-mode $\Lambda_b(1D)$ states in the quark model. It should be emphasized that whether the structure in the $\Lambda_b\pi^+\pi^-$ spectrum correspond to two states or one state should be further clarified with more observations in future experiments. (ii) The $\Lambda_b(2S)$ $|J^P = \frac{1}{2}^+,0\rangle$ state mainly decays into $\Sigma_b^*\pi$ channel, which may be an ideal channel for searching for this $\Lambda_b(2S)$ state in future experiments. (iii) The $\Sigma_b(2S)$ $|J^P = \frac{1}{2}^+,1 \rangle$ and $|J^P = \frac{3}{2}^+,1 \rangle$ dominantly decay into $\Lambda_b\pi$ with $\Gamma \simeq 3.82$ MeV and $\Gamma \simeq 4.72$ MeV, respectively. |
hep-ph/0008032 | Volkov Guennadi | Vladimir Ammosov, Guennadi Volkov | Can Neutrinos Probe Extra Dimensions? | 9 pages | null | null | DFPD-00/TH/39 | hep-ph | null | We conjecture that the topological structure of the gauge symmetries required
by the Calabi-Yau vacuum and the dualities in string/D-branes considered in the
world with some additional dimensions can lead to an extension of the main
principles of the Special Theory of Relativity. The link between the
topological structure of the vacuum and the, hierarchy of the gauge symmetries
could be checked by the existence of the ``almost massless'', ''sterile''
particles. These particles could have flying properties different from the
standard predictions of the STR. It is natural to consider this property for
neutrinos, known up to now ``$U(1)_{em}$ sterile'' particles. Here we discuss
two such effects depending on the possible existence of large and/or small
extra dimensions and what is the maximal speed for both cases.
The effect of large extra dimensions can be directly connected with the
existence of a hidden boost, $c_{hid} >> c_{em}$, excited by new global
dimensions and can lead to the monotonous rise of the neutrino velocity at high
energies, $v_{\nu} > c$.
The effect of small extra dimensions, universal with respect to all
particles, can be connected with the gravitation recoils of the propagation of
neutrino in the space-time vacuum-foam and it leads to the effect of
diminishing the neutrino velocity at high energies.
We propose to check these conjectures for neutrinos of different energies and
species. Limits for existing neutrino data and expected sensitivities of
possible experiments for accelerator - produced neutrinos are considered. It is
pointed out that CERN has the unique opportunity of measuring the indicated
effects.
| [
{
"created": "Thu, 3 Aug 2000 15:44:43 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ammosov",
"Vladimir",
""
],
[
"Volkov",
"Guennadi",
""
]
] | We conjecture that the topological structure of the gauge symmetries required by the Calabi-Yau vacuum and the dualities in string/D-branes considered in the world with some additional dimensions can lead to an extension of the main principles of the Special Theory of Relativity. The link between the topological structure of the vacuum and the, hierarchy of the gauge symmetries could be checked by the existence of the ``almost massless'', ''sterile'' particles. These particles could have flying properties different from the standard predictions of the STR. It is natural to consider this property for neutrinos, known up to now ``$U(1)_{em}$ sterile'' particles. Here we discuss two such effects depending on the possible existence of large and/or small extra dimensions and what is the maximal speed for both cases. The effect of large extra dimensions can be directly connected with the existence of a hidden boost, $c_{hid} >> c_{em}$, excited by new global dimensions and can lead to the monotonous rise of the neutrino velocity at high energies, $v_{\nu} > c$. The effect of small extra dimensions, universal with respect to all particles, can be connected with the gravitation recoils of the propagation of neutrino in the space-time vacuum-foam and it leads to the effect of diminishing the neutrino velocity at high energies. We propose to check these conjectures for neutrinos of different energies and species. Limits for existing neutrino data and expected sensitivities of possible experiments for accelerator - produced neutrinos are considered. It is pointed out that CERN has the unique opportunity of measuring the indicated effects. |
1507.03845 | Samandeep Sharma | Samandeep Sharma and Gulsheen Ahuja | Minimal Set of Texture Specific Quark Mass Matrices | To appear in the proceedings of XXI DAE-BRNS High Energy Physics
Symposium, IIT Guwahati, India, December 2014, based closely on
arXiv:1503.03963, arXiv:1404.5726 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Starting with the most general mass matrices, within the context of Standard
Model and some of its extensions, incorporating the ideas of weak basis
transformations and naturalness, we find that there exists a particular set of
texture specific quark mass matrices which can be considered to be the minimal
viable option.
| [
{
"created": "Tue, 14 Jul 2015 13:34:06 GMT",
"version": "v1"
}
] | 2015-07-15 | [
[
"Sharma",
"Samandeep",
""
],
[
"Ahuja",
"Gulsheen",
""
]
] | Starting with the most general mass matrices, within the context of Standard Model and some of its extensions, incorporating the ideas of weak basis transformations and naturalness, we find that there exists a particular set of texture specific quark mass matrices which can be considered to be the minimal viable option. |
hep-ph/0102107 | Ulrich Heinz | Ulrich Heinz (OSU) | Multi-Boson Effects in Bose-Einstein Interferometry | 7 pages, incl. 1 figure; necessary style file included. Talk given at
the 30th International Symposium on Multiparticle Dynamics, Tihany, Hungary,
Oct. 9-15, 2000. To appear in the proceedings (World Scientific) | null | null | null | hep-ph | null | Multi-boson symmetrization effects on two-particle Bose-Einstein
interferometry are studied for ensembles with arbitrary multiplicity
distributions. In the general case one finds interesting residual correlations
which require a modified framework for extracting information on the source
geometry from two-particle correlation measurements. In sources with high
phase-space densities, multi-boson effects modify the Hanbury Brown-Twiss (HBT)
radius parameters and simultaneously generate strong residual correlations. We
clarify their effect on the correlation strength (intercept parameter) and thus
explain a variety of previously reported puzzling multi-boson symmetrization
phenomena. For event ensembles of (approximately) fixed multiplicity, the
residual correlations lead to a minimum in the correlation function at non-zero
relative momentum, which can be practically exploited to search, in a
model-independent way, for multi-boson symmetrization effects in high-energy
heavy-ion experiments.
| [
{
"created": "Thu, 8 Feb 2001 21:49:33 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Heinz",
"Ulrich",
"",
"OSU"
]
] | Multi-boson symmetrization effects on two-particle Bose-Einstein interferometry are studied for ensembles with arbitrary multiplicity distributions. In the general case one finds interesting residual correlations which require a modified framework for extracting information on the source geometry from two-particle correlation measurements. In sources with high phase-space densities, multi-boson effects modify the Hanbury Brown-Twiss (HBT) radius parameters and simultaneously generate strong residual correlations. We clarify their effect on the correlation strength (intercept parameter) and thus explain a variety of previously reported puzzling multi-boson symmetrization phenomena. For event ensembles of (approximately) fixed multiplicity, the residual correlations lead to a minimum in the correlation function at non-zero relative momentum, which can be practically exploited to search, in a model-independent way, for multi-boson symmetrization effects in high-energy heavy-ion experiments. |
1905.05575 | Peter Cox | Peter Cox, Tom Melia, Surjeet Rajendran | The Dark Matter Phonon Coupling | 17 pages, 1 figure; v2: version published in PRD | Phys. Rev. D 100, 055011 (2019) | 10.1103/PhysRevD.100.055011 | IPMU19-0065 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Generically, the effective coupling between the dark matter and an atom
scales with the number of constituents in the atom, resulting in the effective
coupling being proportional to the mass of the atom. In this limit, when the
momentum transfer is also small, we show that the leading term in the
scattering of a particle off the optical phonons of an array of atoms, whether
in a crystal or in a molecule, vanishes. Next-generation dark matter direct
detection experiments with sub-eV energy thresholds will operate in a regime
where this effect is important, and the suppression can be up to order $10^6$
over naive expectations. For dark matter that couples differently to protons
and neutrons, the suppression is typically of order $10-100$ but can be avoided
through a judicious choice of material, utilising variations in nuclear ratios
$Z/A$ to break the proportionality of the coupling to mass. We provide explicit
illustrations of this effect by calculating structure factors for di-molecules
and for the crystals NaI and sapphire.
| [
{
"created": "Tue, 14 May 2019 13:04:27 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Sep 2019 07:07:31 GMT",
"version": "v2"
}
] | 2019-09-18 | [
[
"Cox",
"Peter",
""
],
[
"Melia",
"Tom",
""
],
[
"Rajendran",
"Surjeet",
""
]
] | Generically, the effective coupling between the dark matter and an atom scales with the number of constituents in the atom, resulting in the effective coupling being proportional to the mass of the atom. In this limit, when the momentum transfer is also small, we show that the leading term in the scattering of a particle off the optical phonons of an array of atoms, whether in a crystal or in a molecule, vanishes. Next-generation dark matter direct detection experiments with sub-eV energy thresholds will operate in a regime where this effect is important, and the suppression can be up to order $10^6$ over naive expectations. For dark matter that couples differently to protons and neutrons, the suppression is typically of order $10-100$ but can be avoided through a judicious choice of material, utilising variations in nuclear ratios $Z/A$ to break the proportionality of the coupling to mass. We provide explicit illustrations of this effect by calculating structure factors for di-molecules and for the crystals NaI and sapphire. |
hep-ph/0110357 | Muneyuki Ishida | Toshihiko Komada (Nihon U.), Muneyuki Ishida (TITech) and Shin Ishida
(Nihon U.) | The sigma-Meson Production in Excited Upsilon Decay Processes | proc. of "Hadron '01," Protvino, Russia, Aug, 2001. 5 pages, uses
ptptex.sty | AIP Conf.Proc. 619 (2002) 499-502 | 10.1063/1.1482478 | null | hep-ph | null | We analyze the pipi production amplitudes in the excited Upsilon decay
processes, Upsilon (2S) to Upsilon (1S)pi^+pi^-, Upsilon (3S) to Upsilon
(1S)pi^+pi^- and Upsilon (3S) to Upsilon (2S)pi^+pi^-, and the pipi and KKbar
production amplitudes in the charmonium decay processes, psi (2S) to Jpsi
pi^+pi^- and Jpsi to phi pi^+pi^-, phi K^+K^-, including the possible effect of
light sigma production. The amplitudes are parametrized by the sum of
Breit-Wigner amplitudes for the sigma and the other relevant particles and of
the direct 2pi-production amplitude, following the VMW method. All the pipi
(and KKbar mass spectra are reproduced well with the obtained values of
sigma-parameters, m_sigma =526(+48,-37)MeV and Gamma_sigma =301(+145,-100)MeV,
which is almost consistent with the values in our previous phase shift
analyses.
| [
{
"created": "Sat, 27 Oct 2001 09:28:23 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Komada",
"Toshihiko",
"",
"Nihon U."
],
[
"Ishida",
"Muneyuki",
"",
"TITech"
],
[
"Ishida",
"Shin",
"",
"Nihon U."
]
] | We analyze the pipi production amplitudes in the excited Upsilon decay processes, Upsilon (2S) to Upsilon (1S)pi^+pi^-, Upsilon (3S) to Upsilon (1S)pi^+pi^- and Upsilon (3S) to Upsilon (2S)pi^+pi^-, and the pipi and KKbar production amplitudes in the charmonium decay processes, psi (2S) to Jpsi pi^+pi^- and Jpsi to phi pi^+pi^-, phi K^+K^-, including the possible effect of light sigma production. The amplitudes are parametrized by the sum of Breit-Wigner amplitudes for the sigma and the other relevant particles and of the direct 2pi-production amplitude, following the VMW method. All the pipi (and KKbar mass spectra are reproduced well with the obtained values of sigma-parameters, m_sigma =526(+48,-37)MeV and Gamma_sigma =301(+145,-100)MeV, which is almost consistent with the values in our previous phase shift analyses. |
1209.5974 | Soon-Tae Hong | Soon-Tae Hong | Kaluza-Klein mass spectra on extended dimensional branes | 8 pages | Mod. Phys. Lett. A29 (2014) 1450190 | 10.1142/S0217732314501909 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the hierarchy problem on the four- and five-branes which are
constructed by attaching a circle and a sphere to the standard three-brane,
respectively. The effective masses in their excited spectra on these extended
dimensional branes imply intriguing characteristics associated with the
quantization of the compact circular and spherical manifolds. In particular,
their lightest effective masses are shown to suppress exponentially with
respective to the Planck mass, similar to the three-brane case. We also
investigate the effective couplings in these extended dimensional branes.
| [
{
"created": "Wed, 26 Sep 2012 15:36:12 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Sep 2012 00:01:41 GMT",
"version": "v2"
},
{
"created": "Fri, 7 Nov 2014 06:26:56 GMT",
"version": "v3"
}
] | 2014-11-10 | [
[
"Hong",
"Soon-Tae",
""
]
] | We study the hierarchy problem on the four- and five-branes which are constructed by attaching a circle and a sphere to the standard three-brane, respectively. The effective masses in their excited spectra on these extended dimensional branes imply intriguing characteristics associated with the quantization of the compact circular and spherical manifolds. In particular, their lightest effective masses are shown to suppress exponentially with respective to the Planck mass, similar to the three-brane case. We also investigate the effective couplings in these extended dimensional branes. |
1305.3308 | Fernando Navarra | C.S. Machado, F.S. Navarra, E.G. de Oliveira, J. Noronha, M.
Strickland | Heavy quarkonium production in a strong magnetic field | 18 pages, 7 figures | null | 10.1103/PhysRevD.88.034009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is well known that in noncentral heavy-ion collisions a transient strong
magnetic field is generated in the direction perpendicular to the reaction
plane. The maximal strength of this field is estimated to be $eB \sim m^2_{\pi}
\sim 0.02 \text{GeV}^2$ at the RHIC and $eB \sim 15 m^2_{\pi} \sim 0.3
\text{GeV}^2$ at the LHC. We investigate the effects of a strong magnetic field
on $B$ and $D$ mesons, focusing on the changes of the energy levels and the
masses of the bound states. Using the Color Evaporation Model we discuss the
possible changes in the production of $J/\psi$ and $\Upsilon$.
| [
{
"created": "Tue, 14 May 2013 21:56:48 GMT",
"version": "v1"
}
] | 2013-08-14 | [
[
"Machado",
"C. S.",
""
],
[
"Navarra",
"F. S.",
""
],
[
"de Oliveira",
"E. G.",
""
],
[
"Noronha",
"J.",
""
],
[
"Strickland",
"M.",
""
]
] | It is well known that in noncentral heavy-ion collisions a transient strong magnetic field is generated in the direction perpendicular to the reaction plane. The maximal strength of this field is estimated to be $eB \sim m^2_{\pi} \sim 0.02 \text{GeV}^2$ at the RHIC and $eB \sim 15 m^2_{\pi} \sim 0.3 \text{GeV}^2$ at the LHC. We investigate the effects of a strong magnetic field on $B$ and $D$ mesons, focusing on the changes of the energy levels and the masses of the bound states. Using the Color Evaporation Model we discuss the possible changes in the production of $J/\psi$ and $\Upsilon$. |
2002.07697 | Juan Antonio Aguilar-Saavedra | J.A. Aguilar-Saavedra, F.R. Joaquim | Multiphoton signals of a (96 GeV?) stealth boson | LaTeX 32 pages. Comments added and discussions extended. Final
version in EPJC | null | 10.1140/epjc/s10052-020-7952-4 | IFT-UAM/CSIC-19-153, CFTP/20-002 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Cascade decays of new scalars into final states with multiple photons and
possibly quarks may lead to distinctive experimental signatures at high-energy
colliders. Such signals are even more striking if the scalars are highly
boosted, as when produced from the decay of a much heavier resonance. We study
this type of events within the framework of the minimal stealth boson model, an
anomaly-free $\text{U}(1)_{Y'}$ extension of the Standard Model with two
complex scalar singlets. It is shown that, while those signals may have cross
sections that might render them observable with LHC Run 2 data, they have
little experimental coverage. We also establish a connection with a CMS excess
observed in searches for new scalars decaying into diphoton final states near
96 GeV. In particular, we conclude that the predicted multiphoton signatures
are compatible with such excess.
| [
{
"created": "Tue, 18 Feb 2020 16:22:11 GMT",
"version": "v1"
},
{
"created": "Wed, 13 May 2020 17:20:18 GMT",
"version": "v2"
}
] | 2020-06-24 | [
[
"Aguilar-Saavedra",
"J. A.",
""
],
[
"Joaquim",
"F. R.",
""
]
] | Cascade decays of new scalars into final states with multiple photons and possibly quarks may lead to distinctive experimental signatures at high-energy colliders. Such signals are even more striking if the scalars are highly boosted, as when produced from the decay of a much heavier resonance. We study this type of events within the framework of the minimal stealth boson model, an anomaly-free $\text{U}(1)_{Y'}$ extension of the Standard Model with two complex scalar singlets. It is shown that, while those signals may have cross sections that might render them observable with LHC Run 2 data, they have little experimental coverage. We also establish a connection with a CMS excess observed in searches for new scalars decaying into diphoton final states near 96 GeV. In particular, we conclude that the predicted multiphoton signatures are compatible with such excess. |
hep-ph/0510151 | John Gracey | J.A. Gracey | Two loop correction to the Gribov mass gap equation in Landau gauge QCD | 8 latex pages | Phys.Lett.B632:282-286,2006; Erratum-ibid.686:319,2010 | 10.1016/j.physletb.2005.10.046 10.1016/j.physletb.2010.02.039 | LTH 677 | hep-ph hep-lat hep-th | null | We determine the two loop correction to Gribov's mass gap equation for
quantum chromodynamics in the Landau gauge in the MSbar scheme by computing the
two loop correction to the horizon condition derived from Zwanziger's local
renormalizable Lagrangian which incorporates the Gribov parameter. We verify
that with the explicit result, the two loop ghost propagator is enchanced in
the infrared.
| [
{
"created": "Wed, 12 Oct 2005 09:18:00 GMT",
"version": "v1"
}
] | 2014-11-18 | [
[
"Gracey",
"J. A.",
""
]
] | We determine the two loop correction to Gribov's mass gap equation for quantum chromodynamics in the Landau gauge in the MSbar scheme by computing the two loop correction to the horizon condition derived from Zwanziger's local renormalizable Lagrangian which incorporates the Gribov parameter. We verify that with the explicit result, the two loop ghost propagator is enchanced in the infrared. |
2212.02442 | Cyrin Neeraj | Jai Bardhan, Tanumoy Mandal, Subhadip Mitra, Cyrin Neeraj | Machine learning-enhanced search for a vectorlike singlet $B$ quark
decaying to a singlet scalar or pseudoscalar | 15 pages, 12 figures and 2 tables. Article matches the published
version | Phys. Rev. D 107 (2023), 115001 | 10.1103/PhysRevD.107.115001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The presence of a new decay mode relaxes the current mass exclusion limits on
vectorlike quarks considerably. We consider the case of a weak-singlet
vectorlike $B$ quark that can decay to a singlet scalar or pseudoscalar $\Phi$.
In an earlier paper [A. Bhardwaj et al., Roadmap to explore vectorlike quarks
decaying to a new scalar or pseudoscalar, Phys. Rev. D, 106 (2022) 095014;
arXiv:2203.13753], we mapped the possibilities to explore such setups at the
LHC. We showed that it is possible for a $B$ quark to decay into $\Phi$ and the
$\Phi$ to dominantly decay to a pair of gluons or $b$ quark(s) without
fine-tuning the parameters. In this paper, we present a collider search
strategy to look for the pair production of singlet $B$ quarks. If both $B$
quarks decay into $b\Phi$ pairs, the final state is fully hadronic:
$B{B}\to(b\Phi)({b}\Phi)\to (bgg)({b}gg)/(bb{b})({b}b{b})$, which is very
challenging to probe. Therefore, we consider a simpler mixed decay specific to
the singlet $B$ case, $BB\to(b\Phi)(tW)$ with a lepton in the final state, to
achieve the best sensitivity at the high-luminosity LHC. We use a deep neural
network with a weighted cross-entropy loss to separate the signal from the huge
SM background. Our analysis shows that large areas of the $M_{B}-M_{\Phi}$
parameter space are discoverable through this signature. We show how the
discovery and exclusion regions scale with the branching ratio in the new decay
mode. We also estimate the reach in the inclusive monolepton channel with the
same network model.
| [
{
"created": "Mon, 5 Dec 2022 17:40:24 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Feb 2023 10:20:03 GMT",
"version": "v2"
},
{
"created": "Sun, 4 Jun 2023 13:40:01 GMT",
"version": "v3"
}
] | 2023-06-06 | [
[
"Bardhan",
"Jai",
""
],
[
"Mandal",
"Tanumoy",
""
],
[
"Mitra",
"Subhadip",
""
],
[
"Neeraj",
"Cyrin",
""
]
] | The presence of a new decay mode relaxes the current mass exclusion limits on vectorlike quarks considerably. We consider the case of a weak-singlet vectorlike $B$ quark that can decay to a singlet scalar or pseudoscalar $\Phi$. In an earlier paper [A. Bhardwaj et al., Roadmap to explore vectorlike quarks decaying to a new scalar or pseudoscalar, Phys. Rev. D, 106 (2022) 095014; arXiv:2203.13753], we mapped the possibilities to explore such setups at the LHC. We showed that it is possible for a $B$ quark to decay into $\Phi$ and the $\Phi$ to dominantly decay to a pair of gluons or $b$ quark(s) without fine-tuning the parameters. In this paper, we present a collider search strategy to look for the pair production of singlet $B$ quarks. If both $B$ quarks decay into $b\Phi$ pairs, the final state is fully hadronic: $B{B}\to(b\Phi)({b}\Phi)\to (bgg)({b}gg)/(bb{b})({b}b{b})$, which is very challenging to probe. Therefore, we consider a simpler mixed decay specific to the singlet $B$ case, $BB\to(b\Phi)(tW)$ with a lepton in the final state, to achieve the best sensitivity at the high-luminosity LHC. We use a deep neural network with a weighted cross-entropy loss to separate the signal from the huge SM background. Our analysis shows that large areas of the $M_{B}-M_{\Phi}$ parameter space are discoverable through this signature. We show how the discovery and exclusion regions scale with the branching ratio in the new decay mode. We also estimate the reach in the inclusive monolepton channel with the same network model. |
hep-ph/0110276 | Nobuhiro Maekawa | Nobuhiro Maekawa | A Road to the Standard Grand Unified Theory | 17 pages, LaTeX, Contribution to "Summer Institute 2001",
Fuji-Yoshida, Japan, August 2001 | null | null | KUNS-1740 | hep-ph | null | In this talk, we propose a GUT scenario in which doublet-triplet splitting is
naturally realized in SO(10) unification using the Dimopoulos-Wilczek mechanism
and the realistic mass matrices of quarks and leptons are obtained in a simple
way. For the neutrino sector, bi-maximal neutrino mixing angles are realized.
Moreover, the generic interaction is allowed, namely, all the terms which are
allowed by the symmetry are included in the scenario. Therefore, once we fix
the integer number charges of the anomalous U(1)_A symmetry, which plays an
essential role in the scenario, all the scales, GUT breaking scale, mass scales
of superheavy particles, are determined. The scenario can be extended into E_6
unification, in which a condition for suppression of flavor changing neutral
current (FCNC) is automatically satisfied.
| [
{
"created": "Mon, 22 Oct 2001 06:30:03 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Maekawa",
"Nobuhiro",
""
]
] | In this talk, we propose a GUT scenario in which doublet-triplet splitting is naturally realized in SO(10) unification using the Dimopoulos-Wilczek mechanism and the realistic mass matrices of quarks and leptons are obtained in a simple way. For the neutrino sector, bi-maximal neutrino mixing angles are realized. Moreover, the generic interaction is allowed, namely, all the terms which are allowed by the symmetry are included in the scenario. Therefore, once we fix the integer number charges of the anomalous U(1)_A symmetry, which plays an essential role in the scenario, all the scales, GUT breaking scale, mass scales of superheavy particles, are determined. The scenario can be extended into E_6 unification, in which a condition for suppression of flavor changing neutral current (FCNC) is automatically satisfied. |
hep-ph/0612261 | Cyrille Marquet | O. Kepka, C. Marquet, R. Peschanski and C. Royon | Next-to-leading BFKL phenomenology of forward-jet cross sections at HERA | 15 pages, 9 figures, new title, NLL-BFKL saddle-point approximation
replaced by exact integration | Eur.Phys.J.C55:259-272,2008 | 10.1140/epjc/s10052-008-0587-5 | null | hep-ph | null | We show that the forward-jet measurements performed at HERA allow for a
detailed study of corrections due to next-to-leading logarithms (NLL) in the
Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach. While the description of the
d\sigma/dx data shows small sensitivity to NLL-BFKL corrections, these can be
tested by the triple differential cross section d\sigma/dxdk_T^2dQ^2 recently
measured. These data can be successfully described using a
renormalization-group improved NLL kernel while the standard
next-to-leading-order QCD or leading-logarithm BFKL approaches fail to describe
the same data in the whole kinematic range. We present a detailed analysis of
the NLL scheme and renormalization-scale dependences and also discuss the
photon impact factors.
| [
{
"created": "Wed, 20 Dec 2006 17:06:51 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Nov 2007 19:23:20 GMT",
"version": "v2"
},
{
"created": "Mon, 21 Apr 2008 22:32:46 GMT",
"version": "v3"
}
] | 2010-03-25 | [
[
"Kepka",
"O.",
""
],
[
"Marquet",
"C.",
""
],
[
"Peschanski",
"R.",
""
],
[
"Royon",
"C.",
""
]
] | We show that the forward-jet measurements performed at HERA allow for a detailed study of corrections due to next-to-leading logarithms (NLL) in the Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach. While the description of the d\sigma/dx data shows small sensitivity to NLL-BFKL corrections, these can be tested by the triple differential cross section d\sigma/dxdk_T^2dQ^2 recently measured. These data can be successfully described using a renormalization-group improved NLL kernel while the standard next-to-leading-order QCD or leading-logarithm BFKL approaches fail to describe the same data in the whole kinematic range. We present a detailed analysis of the NLL scheme and renormalization-scale dependences and also discuss the photon impact factors. |
hep-ph/9910544 | Philip G. Ratcliffe | Philip G. Ratcliffe | Theory Summary Talk | Presented at Hyperon99 Symposium, Fermilab, Batavia, Sept. 27-29,
1999; 10 pages; uses hyperon99_paper.sty and setup.sty (included); and the
following standard LaTeX packages: acromake, axodraw, cite, epsf, topcapt
(not included); 1 eps figure file (using epsf) | null | null | null | hep-ph | null | A summary is presented of the more theoretical aspects of the presentations
made at Hyperon~99. In addition, some material is covered which was not
presented at the symposium but which I feel is pertinent to the main theme of
hyperons and/or, more in particular, to discussions conducted during the
symposium.
| [
{
"created": "Fri, 29 Oct 1999 14:04:56 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ratcliffe",
"Philip G.",
""
]
] | A summary is presented of the more theoretical aspects of the presentations made at Hyperon~99. In addition, some material is covered which was not presented at the symposium but which I feel is pertinent to the main theme of hyperons and/or, more in particular, to discussions conducted during the symposium. |
1402.5278 | Esteban Calzetta | Esteban Calzetta | A hydrodynamic approach to boost invariant free streaming | 20 pages, 8 figures. Accepted for publication in Phys. Rev. D | Phys. Rev. D 92, 045035 (2015) | 10.1103/PhysRevD.92.045035 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a family of exact boost invariant solutions of the transport
equation for free streaming massless particles, where the one particle
distribution function is defined in terms of a function of a single variable.
The evolution of second and third moments of the one particle distribution
function (the second moment being the energy momentum tensor (EMT) and the
third moment the non equilibrium current (NEC)) depends only on two moments of
that function. Given those two moments we show how to build a non linear
hydrodynamic theory which reproduces the early time evolution of the EMT and
the NEC. The structure of these theories may give insight on nonlinear
hydrodynamic phenomena on short time scales.
| [
{
"created": "Fri, 21 Feb 2014 12:32:19 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Mar 2015 21:15:10 GMT",
"version": "v2"
},
{
"created": "Mon, 10 Aug 2015 22:02:07 GMT",
"version": "v3"
}
] | 2016-11-25 | [
[
"Calzetta",
"Esteban",
""
]
] | We consider a family of exact boost invariant solutions of the transport equation for free streaming massless particles, where the one particle distribution function is defined in terms of a function of a single variable. The evolution of second and third moments of the one particle distribution function (the second moment being the energy momentum tensor (EMT) and the third moment the non equilibrium current (NEC)) depends only on two moments of that function. Given those two moments we show how to build a non linear hydrodynamic theory which reproduces the early time evolution of the EMT and the NEC. The structure of these theories may give insight on nonlinear hydrodynamic phenomena on short time scales. |
1907.09684 | Zhao-Huan Yu | Xue-Min Jiang, Chengfeng Cai, Zhao-Huan Yu, Yu-Pan Zeng, Hong-Hao
Zhang | Pseudo-Nambu-Goldstone dark matter and two-Higgs-doublet models | 33 pages, 11 figures; revisions to match the published version | Phys. Rev. D 100, 075011 (2019) | 10.1103/PhysRevD.100.075011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a dark matter model with one singlet complex scalar and two Higgs
doublets. The scalar potential respects a softly broken global symmetry, which
makes the imaginary part of the singlet become a pseudo-Nambu-Goldstone boson
acting as a dark matter candidate. The pseudo-Nambu-Goldstone nature of the
boson leads to the vanishing of its tree-level scattering amplitude off
nucleons at zero momentum transfer. Therefore, although the interaction
strength could be sufficiently large to yield a viable relic abundance via
thermal mechanism, direct detection is incapable of probing this candidate. We
further investigate the constraints from Higgs measurements, relic abundance
observation, and indirect detection.
| [
{
"created": "Tue, 23 Jul 2019 03:59:25 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Jul 2019 07:32:05 GMT",
"version": "v2"
},
{
"created": "Fri, 11 Oct 2019 03:46:07 GMT",
"version": "v3"
}
] | 2019-10-14 | [
[
"Jiang",
"Xue-Min",
""
],
[
"Cai",
"Chengfeng",
""
],
[
"Yu",
"Zhao-Huan",
""
],
[
"Zeng",
"Yu-Pan",
""
],
[
"Zhang",
"Hong-Hao",
""
]
] | We study a dark matter model with one singlet complex scalar and two Higgs doublets. The scalar potential respects a softly broken global symmetry, which makes the imaginary part of the singlet become a pseudo-Nambu-Goldstone boson acting as a dark matter candidate. The pseudo-Nambu-Goldstone nature of the boson leads to the vanishing of its tree-level scattering amplitude off nucleons at zero momentum transfer. Therefore, although the interaction strength could be sufficiently large to yield a viable relic abundance via thermal mechanism, direct detection is incapable of probing this candidate. We further investigate the constraints from Higgs measurements, relic abundance observation, and indirect detection. |
hep-ph/0112163 | Gi-Chol Cho | Gi-Chol Cho (Ochanomizu Univ.), Naoyuki Haba (Mie Univ.) and Junji
Hisano (KEK) | The stau exchange contribution to muon g-2 in the decoupling solution | 11 pages, latex2e with axodraw.sty, comments and reference added | Phys.Lett. B529 (2002) 117-123 | 10.1016/S0370-2693(02)01252-2 | OCHA-PP-183, KEK-TH-792 | hep-ph | null | We study the possibility that the lepton-flavor changing process can induce
the suitable magnitude of the muon anomalous magnetic moment (g_\mu -2) in the
decoupling solution to the flavor problem in the minimal supersymmetric
standard model. Our analyses introduce the flavor mixings of left- and
right-handed stau and smuon phenomenologically. It is found that if both the
left- and right-handed sleptons have sizable flavor mixings, the correction to
g_\mu -2 from the lighter slepton can reach to 10^{-9} while the correction to
the branching ratio of \tau \to \mu \gamma satisfies the current experimental
bound. On the other hand, when only the left-handed or right-handed sleptons
have the large flavor mixing, the suitable magnitude of the correction to
g_\mu-2 is not realized owing to the experimental bound of \tau \to \mu \gamma.
| [
{
"created": "Wed, 12 Dec 2001 04:44:47 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Jan 2002 07:06:02 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Cho",
"Gi-Chol",
"",
"Ochanomizu Univ."
],
[
"Haba",
"Naoyuki",
"",
"Mie Univ."
],
[
"Hisano",
"Junji",
"",
"KEK"
]
] | We study the possibility that the lepton-flavor changing process can induce the suitable magnitude of the muon anomalous magnetic moment (g_\mu -2) in the decoupling solution to the flavor problem in the minimal supersymmetric standard model. Our analyses introduce the flavor mixings of left- and right-handed stau and smuon phenomenologically. It is found that if both the left- and right-handed sleptons have sizable flavor mixings, the correction to g_\mu -2 from the lighter slepton can reach to 10^{-9} while the correction to the branching ratio of \tau \to \mu \gamma satisfies the current experimental bound. On the other hand, when only the left-handed or right-handed sleptons have the large flavor mixing, the suitable magnitude of the correction to g_\mu-2 is not realized owing to the experimental bound of \tau \to \mu \gamma. |
1403.3099 | James Maxin | Tristan Leggett, Tianjun Li, James A. Maxin, Dimitri V. Nanopoulos,
and Joel W. Walker | No Naturalness or Fine-tuning Problems from No-Scale Supergravity | 6 pages, 1 figure | null | null | ACT-2-14 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the electroweak fine-tuning in No-Scale Supergravity for a
representative supersymmetric Grand Unification Theory (GUT) model, flipped
$SU(5)$ with extra vector-like $flippons$, dubbed $\cal{F}$-$SU(5)$. We find
that there is no problematic electroweak fine-tuning in No-Scale
$\cal{F}$-$SU(5)$, due to an elegant proportional rescaling of the full mass
spectrum with respect to just the unified gaugino mass $M_{1/2}$, as well as a
dynamic equivalence enforced between $M_{1/2}$ and the supersymmetric Higgs
mixing parameter $\mu$ at the heavy unification scale. We demonstrate both
analytically and numerically that the No-Scale $\cal{F}$-$SU(5)$ fine-tuning
parameter is consequently of unit order, $\Delta_{\rm EENZ} \simeq {\cal
O}(1)$, at the electroweak scale.
| [
{
"created": "Wed, 12 Mar 2014 20:01:13 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Aug 2014 18:55:00 GMT",
"version": "v2"
}
] | 2014-08-27 | [
[
"Leggett",
"Tristan",
""
],
[
"Li",
"Tianjun",
""
],
[
"Maxin",
"James A.",
""
],
[
"Nanopoulos",
"Dimitri V.",
""
],
[
"Walker",
"Joel W.",
""
]
] | We compute the electroweak fine-tuning in No-Scale Supergravity for a representative supersymmetric Grand Unification Theory (GUT) model, flipped $SU(5)$ with extra vector-like $flippons$, dubbed $\cal{F}$-$SU(5)$. We find that there is no problematic electroweak fine-tuning in No-Scale $\cal{F}$-$SU(5)$, due to an elegant proportional rescaling of the full mass spectrum with respect to just the unified gaugino mass $M_{1/2}$, as well as a dynamic equivalence enforced between $M_{1/2}$ and the supersymmetric Higgs mixing parameter $\mu$ at the heavy unification scale. We demonstrate both analytically and numerically that the No-Scale $\cal{F}$-$SU(5)$ fine-tuning parameter is consequently of unit order, $\Delta_{\rm EENZ} \simeq {\cal O}(1)$, at the electroweak scale. |
hep-ph/9812256 | Apostolos Pilaftsis | Apostolos Pilaftsis | Heavy Majorana Neutrinos and Baryogenesis | 48 pages, minor rewordings | Int.J.Mod.Phys.A14:1811-1858,1999 | 10.1142/S0217751X99000932 | CERN-TH/98-386 | hep-ph astro-ph hep-ex | null | The scenario of baryogenesis through leptogenesis is reviewed in models
involving heavy Majorana neutrinos. The various mechanisms of CP violation
occurring in the out-of-equilibrium lepton-number-violating decays of heavy
Majorana neutrinos are studied within a resummation approach to
unstable-particle mixing. It is explicitly demonstrated how the resummation
approach preserves crucial field-theoretic properties such as unitarity and CPT
invariance. Predictions of representative scenarios are presented after solving
numerically the Boltzmann equations describing the thermodynamic evolution of
the Universe. The phenomenological consequences of loop effects of heavy
Majorana neutrinos on low-energy observables, such as lepton-flavour and/or
lepton-number non-conservation in $\tau$ and $Z$-boson decays and electron
electric dipole moment, are discussed.
| [
{
"created": "Fri, 4 Dec 1998 17:47:07 GMT",
"version": "v1"
},
{
"created": "Sat, 26 Dec 1998 14:13:44 GMT",
"version": "v2"
},
{
"created": "Wed, 17 Feb 1999 16:08:59 GMT",
"version": "v3"
}
] | 2011-08-17 | [
[
"Pilaftsis",
"Apostolos",
""
]
] | The scenario of baryogenesis through leptogenesis is reviewed in models involving heavy Majorana neutrinos. The various mechanisms of CP violation occurring in the out-of-equilibrium lepton-number-violating decays of heavy Majorana neutrinos are studied within a resummation approach to unstable-particle mixing. It is explicitly demonstrated how the resummation approach preserves crucial field-theoretic properties such as unitarity and CPT invariance. Predictions of representative scenarios are presented after solving numerically the Boltzmann equations describing the thermodynamic evolution of the Universe. The phenomenological consequences of loop effects of heavy Majorana neutrinos on low-energy observables, such as lepton-flavour and/or lepton-number non-conservation in $\tau$ and $Z$-boson decays and electron electric dipole moment, are discussed. |
hep-ph/0304203 | Tatsu Takeuchi | Tatsu Takeuchi, Will Loinaz, Naotoshi Okamura, and L. C. R.
Wijewardhana | The W mass and the U parameter | 7 pages, 6 postscript figures. Talk presented by Takeuchi at SCGT'02,
December 13, 2002, Nagoya, Japan. Uses ws-procs9x6.cls (included) | null | 10.1142/9789812795120_0040 | VPI-IPPAP-03-04 | hep-ph | null | The Z-pole data from e+e- colliders and results from the NuTeV experiment at
Fermilab can be brought into agreement if (1) the neutrino-Z couplings were
suppressed relative to the Standard Model (SM), and (2) the Higgs boson were
much heavier than suggested by SM global fits. However, increasing the Higgs
boson mass will move the theoretical value of the W mass away from its
experimental value. A large and positive U parameter becomes necessary to
account for the difference. We discuss what type of new physics may lead to
such values of U.
| [
{
"created": "Tue, 22 Apr 2003 06:49:02 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Takeuchi",
"Tatsu",
""
],
[
"Loinaz",
"Will",
""
],
[
"Okamura",
"Naotoshi",
""
],
[
"Wijewardhana",
"L. C. R.",
""
]
] | The Z-pole data from e+e- colliders and results from the NuTeV experiment at Fermilab can be brought into agreement if (1) the neutrino-Z couplings were suppressed relative to the Standard Model (SM), and (2) the Higgs boson were much heavier than suggested by SM global fits. However, increasing the Higgs boson mass will move the theoretical value of the W mass away from its experimental value. A large and positive U parameter becomes necessary to account for the difference. We discuss what type of new physics may lead to such values of U. |
2403.07759 | Stefano Palmisano | Stefano Palmisano, Francesco Rescigno, and Federica Troni | Models of Accidental Dark Matter with a Fundamental Scalar | 27 pages + appendices | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We consider models of accidental dark matter, namely models in which the dark
matter is a composite state that is stable thanks to an accidental symmetry of
the theory. The fundamental constituents are vectorlike fermions, taken to be
fragments of representations of the grand unifying gauge group $SU(5)$, as well
as a scalar singlet. All the new fields are charged under a new confining gauge
group, which we take to be $SU(N)$, leading to models with complex dark matter.
We analyse the models in the context of $SU(5)$ grand unification with a
non-standard approach recently proposed in the literature. The advantage of
including the scalar mainly resides in the fact that it allows several
undesired accidental symmetries to be broken, leading to a larger set of viable
models with respect to previous literature, in which only fermions (or only
scalars) were considered. Moreover these models present distinct novelties,
namely dark states with non-zero baryon and lepton number and the existence of
composite hybrid states of fermions and scalars. We identify phenomena that are
specific to the inclusion of the scalar and discuss possibilities to test this
setup.
| [
{
"created": "Tue, 12 Mar 2024 15:45:58 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Mar 2024 15:16:29 GMT",
"version": "v2"
},
{
"created": "Fri, 9 Aug 2024 11:05:40 GMT",
"version": "v3"
}
] | 2024-08-12 | [
[
"Palmisano",
"Stefano",
""
],
[
"Rescigno",
"Francesco",
""
],
[
"Troni",
"Federica",
""
]
] | We consider models of accidental dark matter, namely models in which the dark matter is a composite state that is stable thanks to an accidental symmetry of the theory. The fundamental constituents are vectorlike fermions, taken to be fragments of representations of the grand unifying gauge group $SU(5)$, as well as a scalar singlet. All the new fields are charged under a new confining gauge group, which we take to be $SU(N)$, leading to models with complex dark matter. We analyse the models in the context of $SU(5)$ grand unification with a non-standard approach recently proposed in the literature. The advantage of including the scalar mainly resides in the fact that it allows several undesired accidental symmetries to be broken, leading to a larger set of viable models with respect to previous literature, in which only fermions (or only scalars) were considered. Moreover these models present distinct novelties, namely dark states with non-zero baryon and lepton number and the existence of composite hybrid states of fermions and scalars. We identify phenomena that are specific to the inclusion of the scalar and discuss possibilities to test this setup. |
hep-ph/9307287 | null | Alan R. White | The Mass of the Heavy Axion $\eta_6$ | 8 pages, ANL-HEP-CP-93-56 | null | null | null | hep-ph | null | If electroweak dynamical symmetry breaking is due to a chiral condensate of
color sextet quarks, dynamics analagous to ``walking technicolor'' will enhance
the condensate by orders of magnitude compared to the electroweak chiral scale.
This enhancement compensates for the exponential suppression of electroweak
scale color instanton interactions. As a result the $\eta_6$ axion can
naturally aquire an electroweak scale mass.
| [
{
"created": "Fri, 16 Jul 1993 14:04:04 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"White",
"Alan R.",
""
]
] | If electroweak dynamical symmetry breaking is due to a chiral condensate of color sextet quarks, dynamics analagous to ``walking technicolor'' will enhance the condensate by orders of magnitude compared to the electroweak chiral scale. This enhancement compensates for the exponential suppression of electroweak scale color instanton interactions. As a result the $\eta_6$ axion can naturally aquire an electroweak scale mass. |
hep-ph/0001231 | Fabio Finelli | F. Finelli (Purdue U., Bologna U. & INFN & TeSRE, Bologna), A.
Gruppuso (Bologna U. & INFN, Bologna) | Resonant Amplification of Gauge Fields in Expanding Universe | 6 pages, title changed, one section added, version accepted on PLB | Phys.Lett.B502:216-222,2001 | 10.1016/S0370-2693(01)00199-X | PURD-TH-00-01 | hep-ph astro-ph gr-qc hep-th | null | We investigate the possibility that gauge fluctuations are amplified in an
expanding universe by parametric resonance, during the oscillatory regime of a
scalar field to which they are coupled. We investigate the couplings of gauge
fields to a charged scalar field and to an axion. For both couplings, gauge
field fluctuations undergo exponential instabilities. We discuss how the
presence of other charges or currents may counteract the resonance, but we
argue that in some cases the resonance will persist and that hence this
mechanism could have some relevance for the problem of large scale primordial
magnetic fields.
| [
{
"created": "Sun, 23 Jan 2000 18:15:38 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Feb 2001 04:26:56 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Finelli",
"F.",
"",
"Purdue U., Bologna U. & INFN & TeSRE, Bologna"
],
[
"Gruppuso",
"A.",
"",
"Bologna U. & INFN, Bologna"
]
] | We investigate the possibility that gauge fluctuations are amplified in an expanding universe by parametric resonance, during the oscillatory regime of a scalar field to which they are coupled. We investigate the couplings of gauge fields to a charged scalar field and to an axion. For both couplings, gauge field fluctuations undergo exponential instabilities. We discuss how the presence of other charges or currents may counteract the resonance, but we argue that in some cases the resonance will persist and that hence this mechanism could have some relevance for the problem of large scale primordial magnetic fields. |
hep-ph/0407157 | Shi-Lin Zhu | Y.-R. Liu, Y.-B. Dai, C. Liu, Shi-Lin Zhu | $D_{sJ}^+(2632)$: An Excellent Candidate of Tetraquarks | null | Phys.Rev.D70:094009,2004 | 10.1103/PhysRevD.70.094009 | null | hep-ph hep-ex nucl-ex nucl-th | null | We analyze various possible interpretations of the narrow state
$D_{sJ}(2632)$ which lies 100 MeV above threshold. This interesting state
decays mainly into $D_s \eta$ instead of $D^0 K^+$. If this relative branching
ratio is further confirmed by other experimental groups, we point out that the
identification of $D_{sJ}(2632)$ either as a $c\bar s$ state or more generally
as a ${\bf {\bar 3}}$ state in the $SU(3)_F$ representation is probably
problematic. Instead, such an anomalous decay pattern strongly indicates
$D_{sJ}(2632)$ is a four quark state in the $SU(3)_F$ ${\bf 15}$ representation
with the quark content ${1\over 2\sqrt{2}}
(ds\bar{d}+sd\bar{d}+su\bar{u}+us\bar{u}-2ss\bar{s})\bar{c}$. We discuss its
partners in the same multiplet, and the similar four-quark states composed of a
bottom quark $B_{sJ}^0(5832)$. Experimental searches of other members
especially those exotic ones are strongly called for.
| [
{
"created": "Wed, 14 Jul 2004 07:04:09 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Liu",
"Y. -R.",
""
],
[
"Dai",
"Y. -B.",
""
],
[
"Liu",
"C.",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] | We analyze various possible interpretations of the narrow state $D_{sJ}(2632)$ which lies 100 MeV above threshold. This interesting state decays mainly into $D_s \eta$ instead of $D^0 K^+$. If this relative branching ratio is further confirmed by other experimental groups, we point out that the identification of $D_{sJ}(2632)$ either as a $c\bar s$ state or more generally as a ${\bf {\bar 3}}$ state in the $SU(3)_F$ representation is probably problematic. Instead, such an anomalous decay pattern strongly indicates $D_{sJ}(2632)$ is a four quark state in the $SU(3)_F$ ${\bf 15}$ representation with the quark content ${1\over 2\sqrt{2}} (ds\bar{d}+sd\bar{d}+su\bar{u}+us\bar{u}-2ss\bar{s})\bar{c}$. We discuss its partners in the same multiplet, and the similar four-quark states composed of a bottom quark $B_{sJ}^0(5832)$. Experimental searches of other members especially those exotic ones are strongly called for. |
0905.1399 | Stanislaw Jadach | S. Jadach and M. Skrzypek | QCD evolution in the fully unintegrated form | 17 figures | Acta Phys.Polon.B40:2071-2096,2009 | null | IFJPAN-IV-2009-3 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The next-to-leading order (NLO) evolution of the parton distribution
functions (PDF's) in QCD is the "industry standard" in the lepton-hadron and
hadron-hadron collider data analysis. The standard NLO DGLAP evolution is
formulated for inclusive (integrated) PDFs and is done using inclusive NLO
kernels. We report here on the ongoing project, called KRKMC, in which NLO
DGLAP evolution is performed for the exclusive multiparton (fully unintegrated)
distributions (ePDF's) with the help of the exclusive kernels. These kernels
are calculated within the two-parton phase space for bremsstrahlung subset of
the Feynman diagrams of the non-singlet evolution, using
Curci-Furmanski-Petronzio factorization scheme. The multiparton distribution
with multiple use of the exclusive NLO kernels is implemented in the Monte
Carlo program simulating multi-gluon emission from single quark emitter. With
high statistics tests ($\sim 10^{9}$ events) it is shown that the new scheme
works perfectly well in practice and is equivalent at the inclusive level with
the traditional inclusive NLO DGLAP evolution. Once completed, this Monte Carlo
module is aimed as a building block for the NLO parton shower Monte Carlo, for
W/Z production at LHC and for ep scattering, as well as a starting point for
other perturbative QCD based Monte Carlo projects.
| [
{
"created": "Sat, 9 May 2009 20:39:01 GMT",
"version": "v1"
}
] | 2009-10-02 | [
[
"Jadach",
"S.",
""
],
[
"Skrzypek",
"M.",
""
]
] | The next-to-leading order (NLO) evolution of the parton distribution functions (PDF's) in QCD is the "industry standard" in the lepton-hadron and hadron-hadron collider data analysis. The standard NLO DGLAP evolution is formulated for inclusive (integrated) PDFs and is done using inclusive NLO kernels. We report here on the ongoing project, called KRKMC, in which NLO DGLAP evolution is performed for the exclusive multiparton (fully unintegrated) distributions (ePDF's) with the help of the exclusive kernels. These kernels are calculated within the two-parton phase space for bremsstrahlung subset of the Feynman diagrams of the non-singlet evolution, using Curci-Furmanski-Petronzio factorization scheme. The multiparton distribution with multiple use of the exclusive NLO kernels is implemented in the Monte Carlo program simulating multi-gluon emission from single quark emitter. With high statistics tests ($\sim 10^{9}$ events) it is shown that the new scheme works perfectly well in practice and is equivalent at the inclusive level with the traditional inclusive NLO DGLAP evolution. Once completed, this Monte Carlo module is aimed as a building block for the NLO parton shower Monte Carlo, for W/Z production at LHC and for ep scattering, as well as a starting point for other perturbative QCD based Monte Carlo projects. |
0707.1789 | Joaquim Prades | Joaquim Prades (Granada and CERN) | ChPT Progress on Non-Leptonic and Radiative Kaon Decays | 14 pages, 1 figure. Invited talk at KAON 07 International Conference,
May 21-25 2007, Frascati, Italy. v2: Discussion in Section 3 somewhat
enlarged and added references. Matches published verion | PoSKAON:022,2008 | null | CERN-PH-TH/2007-108 | hep-ph hep-ex hep-lat | null | I discuss recent developments on non-leptonic and radiative kaon decays
mainly related to direct CP-violation within the combined ChPT and 1/N_c
expansion approaches. In particular, I review the status of K -> pi pi,
epsilon_K', direct CP-violating K+ -> 3 pi Dalitz plot slope g and decay rate
asymmetries, and the Standard Model prediction for Br(K_L -> pi0 e+ e-).
| [
{
"created": "Thu, 12 Jul 2007 14:03:20 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Sep 2007 15:43:16 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Prades",
"Joaquim",
"",
"Granada and CERN"
]
] | I discuss recent developments on non-leptonic and radiative kaon decays mainly related to direct CP-violation within the combined ChPT and 1/N_c expansion approaches. In particular, I review the status of K -> pi pi, epsilon_K', direct CP-violating K+ -> 3 pi Dalitz plot slope g and decay rate asymmetries, and the Standard Model prediction for Br(K_L -> pi0 e+ e-). |
hep-ph/0505125 | Vitor Cardoso | Vitor Cardoso, Emanuele Berti, Marco Cavaglia | What we (don't) know about black hole formation in high-energy
collisions | 6 pages, ReVTeX 4. Minor corrections and some relevant references
added | Class.Quant.Grav.22:L61-R84,2005 | 10.1088/0264-9381/22/12/L01 | null | hep-ph astro-ph gr-qc hep-th | null | Higher-dimensional scenarios allow for the formation of mini-black holes from
TeV-scale particle collisions. The purpose of this paper is to review and
compare different methods for the estimate of the total gravitational energy
emitted in this process. To date, black hole formation has mainly been studied
using an apparent horizon search technique. This approach yields only an upper
bound on the gravitational energy emitted during black hole formation.
Alternative calculations based on instantaneous collisions of point particles
and black hole perturbation theory suggest that the emitted gravitational
energy may be smaller. New and more refined methods may be necessary to
accurately describe black hole formation in high-energy particle collisions.
| [
{
"created": "Fri, 13 May 2005 21:01:54 GMT",
"version": "v1"
},
{
"created": "Sun, 29 May 2005 14:52:09 GMT",
"version": "v2"
}
] | 2011-01-31 | [
[
"Cardoso",
"Vitor",
""
],
[
"Berti",
"Emanuele",
""
],
[
"Cavaglia",
"Marco",
""
]
] | Higher-dimensional scenarios allow for the formation of mini-black holes from TeV-scale particle collisions. The purpose of this paper is to review and compare different methods for the estimate of the total gravitational energy emitted in this process. To date, black hole formation has mainly been studied using an apparent horizon search technique. This approach yields only an upper bound on the gravitational energy emitted during black hole formation. Alternative calculations based on instantaneous collisions of point particles and black hole perturbation theory suggest that the emitted gravitational energy may be smaller. New and more refined methods may be necessary to accurately describe black hole formation in high-energy particle collisions. |
hep-ph/0509023 | Fredrick Olness | Stefan Berge, Pavel M. Nadolsky, and Fredrick I. Olness | Heavy-flavor effects in soft gluon resummation for electroweak boson
production at hadron colliders | 26 pages, 6 figures | Phys.Rev.D73:013002,2006 | 10.1103/PhysRevD.73.013002 | ANL-HEP-PR-05-73 | hep-ph | null | We evaluate the impact of heavy-quark masses on transverse momentum
distributions of W, Z, and supersymmetric neutral Higgs bosons at the Tevatron
and LHC. The masses of charm and bottom quarks act as non-negligible momentum
scales at small transverse momentum, and affect resummation of soft and
collinear radiation. We point out inconsistencies in the treatment of
heavy-flavor channels at small transverse momentum in massless factorization
schemes, and formulate small transverse momentum resummation in a general-mass
variable flavor number factorization scheme. The improved treatment of the
quark mass dependence leads to non-negligible effects in precision measurements
of the W boson mass at the LHC, and may cause observable modifications in
production of Higgs bosons and other particles in heavy-quark scattering.
| [
{
"created": "Sun, 4 Sep 2005 22:32:45 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Berge",
"Stefan",
""
],
[
"Nadolsky",
"Pavel M.",
""
],
[
"Olness",
"Fredrick I.",
""
]
] | We evaluate the impact of heavy-quark masses on transverse momentum distributions of W, Z, and supersymmetric neutral Higgs bosons at the Tevatron and LHC. The masses of charm and bottom quarks act as non-negligible momentum scales at small transverse momentum, and affect resummation of soft and collinear radiation. We point out inconsistencies in the treatment of heavy-flavor channels at small transverse momentum in massless factorization schemes, and formulate small transverse momentum resummation in a general-mass variable flavor number factorization scheme. The improved treatment of the quark mass dependence leads to non-negligible effects in precision measurements of the W boson mass at the LHC, and may cause observable modifications in production of Higgs bosons and other particles in heavy-quark scattering. |
0801.4108 | Kazunori Kohri | Eung Jin Chun (KIAS), Hang Bae Kim (Hanyang Univ.), Kazunori Kohri
(Lancaster), David H. Lyth (Lancaster) | Flaxino dark matter and stau decay | 9 pages, 4 figures, to appear in JHEP | JHEP0803:061,2008 | 10.1088/1126-6708/2008/03/061 | null | hep-ph astro-ph | null | If the spontaneous breaking of Peccei-Quinn symmetry comes from soft
supersymmetry breaking, the fermionic partners of the symmetry-breaking fields
have mass of order the gravitino mass, and are called flatinos. The lightest
flatino, called here the flaxino, is a CDM candidate if it is the lightest
supersymmetric particle. We here explore flaxino dark matter assuming that the
lightest ordinary supersymmetric particle is the stau, with gravity-mediated
supersymmetry breaking. The decay of the stau to the flaxino is fast enough not
to spoil the standard predictions of Big Bang Nucleosynthesis, and its track
and decay can be seen in future colliders.
| [
{
"created": "Mon, 28 Jan 2008 17:32:14 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Mar 2008 15:07:16 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Chun",
"Eung Jin",
"",
"KIAS"
],
[
"Kim",
"Hang Bae",
"",
"Hanyang Univ."
],
[
"Kohri",
"Kazunori",
"",
"Lancaster"
],
[
"Lyth",
"David H.",
"",
"Lancaster"
]
] | If the spontaneous breaking of Peccei-Quinn symmetry comes from soft supersymmetry breaking, the fermionic partners of the symmetry-breaking fields have mass of order the gravitino mass, and are called flatinos. The lightest flatino, called here the flaxino, is a CDM candidate if it is the lightest supersymmetric particle. We here explore flaxino dark matter assuming that the lightest ordinary supersymmetric particle is the stau, with gravity-mediated supersymmetry breaking. The decay of the stau to the flaxino is fast enough not to spoil the standard predictions of Big Bang Nucleosynthesis, and its track and decay can be seen in future colliders. |
1712.05316 | Peter Schweitzer | Jonathan Hudson, Peter Schweitzer | D-term and structure of point-like and composed spin-0 particles | 26 pages, 3 figures | Phys.Rev.D 96, 114013 (2017) | 10.1103/PhysRevD.96.114013 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This work deals with form factors of the energy-momentum tensor (EMT) of
spin-0 particles and the unknown particle property D-term related to the EMT,
and is divided into three parts.
The first part explores free, weakly and strongly interacting theories to
study EMT form factors with the following findings. (i) The free Klein-Gordon
theory predicts for the D-term D = -1. (ii) Even infinitesimally small
interactions can drastically impact D. (iii) In strongly interacting theories
one can encounter large negative D though notable exceptions exist, which
includes Goldstone bosons of chiral symmetry breaking. (iv) Contrary to common
belief one cannot arbitrarily add "total derivatives" to the EMT. Rather the
EMT must be defined in an unambiguous way.
The second part deals with the interpretation of EMT form factors in terms of
3D-densities with following results. (i) The 3D-density formalism is internally
consistent. (ii) The description is subject to relativistic corrections which
are acceptably small in phenomenologically relevant situations including
nucleon and nuclei. (iii) The free field result D=-1 persists when a spin-0
boson is not point-like but "heuristically given some internal structure."
The third part investigates the question, whether such "giving of an extended
structure" can be implemented dynamically, and has the following insights. (i)
We construct a consistent microscopic theory which, in a certain parametric
limit, interpolates between extended and point-like solutions. (ii) This theory
is exactly solvable which is rare in 3+1 dimensions, admits non-topological
solitons of Q-ball-type, and has a Gaussian field amplitude. (iii) The
interaction of this theory belongs to a class of logarithmic potentials which
were discussed in literature, albeit in different contexts including beyond
standard model phenomenology, cosmology, and Higgs physics.
| [
{
"created": "Thu, 14 Dec 2017 16:23:14 GMT",
"version": "v1"
}
] | 2017-12-15 | [
[
"Hudson",
"Jonathan",
""
],
[
"Schweitzer",
"Peter",
""
]
] | This work deals with form factors of the energy-momentum tensor (EMT) of spin-0 particles and the unknown particle property D-term related to the EMT, and is divided into three parts. The first part explores free, weakly and strongly interacting theories to study EMT form factors with the following findings. (i) The free Klein-Gordon theory predicts for the D-term D = -1. (ii) Even infinitesimally small interactions can drastically impact D. (iii) In strongly interacting theories one can encounter large negative D though notable exceptions exist, which includes Goldstone bosons of chiral symmetry breaking. (iv) Contrary to common belief one cannot arbitrarily add "total derivatives" to the EMT. Rather the EMT must be defined in an unambiguous way. The second part deals with the interpretation of EMT form factors in terms of 3D-densities with following results. (i) The 3D-density formalism is internally consistent. (ii) The description is subject to relativistic corrections which are acceptably small in phenomenologically relevant situations including nucleon and nuclei. (iii) The free field result D=-1 persists when a spin-0 boson is not point-like but "heuristically given some internal structure." The third part investigates the question, whether such "giving of an extended structure" can be implemented dynamically, and has the following insights. (i) We construct a consistent microscopic theory which, in a certain parametric limit, interpolates between extended and point-like solutions. (ii) This theory is exactly solvable which is rare in 3+1 dimensions, admits non-topological solitons of Q-ball-type, and has a Gaussian field amplitude. (iii) The interaction of this theory belongs to a class of logarithmic potentials which were discussed in literature, albeit in different contexts including beyond standard model phenomenology, cosmology, and Higgs physics. |
1112.2298 | Nathaniel Craig | Emmanuel Contreras-Campana, Nathaniel Craig, Richard Gray, Can Kilic,
Michael Park, Sunil Somalwar, Scott Thomas | Multi-Lepton Signals of the Higgs Boson | 21 pages, 4 figures, 4 tables | null | 10.1007/JHEP04(2012)112 | RU-NHETC-2011-21, UTTG-25-11, TCC-028-11 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The possibility of searching for the Higgs boson in channels with multiple
non-resonant leptons is evaluated in light of recent advances in multi-lepton
search techniques at the LHC. The total multi-lepton Higgs signal exceeds the
four lepton gold-plated resonant mode, but is spread over many channels with
same-sign di-lepton, tri-lepton, and four lepton final states. While any
individual channel alone is not significant, the exclusive combination across
multiple channels is shown to provide a sensitivity competitive with other
discovery level searches for the Higgs boson. We estimate that with 5 inverse
femtobarn of data, existing non-optimized multi-lepton searches at the LHC
could exclude the Higgs boson to 95% CL at a few times the predicted Standard
Model cross section in the mass range 120-150 GeV. Refinements focused
specifically on the Higgs boson signal are suggested that would further
increase sensitivity. We illustrate the possibility of discerning patterns in
production and decay modes using correlations across multiple channels by
comparing sensitivities to Standard Model, Fermi-phobic, and b-phobic Higgs
bosons.
| [
{
"created": "Sat, 10 Dec 2011 18:58:29 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Contreras-Campana",
"Emmanuel",
""
],
[
"Craig",
"Nathaniel",
""
],
[
"Gray",
"Richard",
""
],
[
"Kilic",
"Can",
""
],
[
"Park",
"Michael",
""
],
[
"Somalwar",
"Sunil",
""
],
[
"Thomas",
"Scott",
""
]
] | The possibility of searching for the Higgs boson in channels with multiple non-resonant leptons is evaluated in light of recent advances in multi-lepton search techniques at the LHC. The total multi-lepton Higgs signal exceeds the four lepton gold-plated resonant mode, but is spread over many channels with same-sign di-lepton, tri-lepton, and four lepton final states. While any individual channel alone is not significant, the exclusive combination across multiple channels is shown to provide a sensitivity competitive with other discovery level searches for the Higgs boson. We estimate that with 5 inverse femtobarn of data, existing non-optimized multi-lepton searches at the LHC could exclude the Higgs boson to 95% CL at a few times the predicted Standard Model cross section in the mass range 120-150 GeV. Refinements focused specifically on the Higgs boson signal are suggested that would further increase sensitivity. We illustrate the possibility of discerning patterns in production and decay modes using correlations across multiple channels by comparing sensitivities to Standard Model, Fermi-phobic, and b-phobic Higgs bosons. |
2106.04077 | Vivek Kumar Nautiyal | Vivek Kumar Nautiyal, Bipin Singh Koranga, Jaydip Singh | Neutrino Mass Eigenvalues for Different Scheme within Four Flavor
Neutrino framework | 18 pages, 3 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we discuss neutrino mass eigenvalues for four flavor neutrino
mixing. An extra mass states, in four flavor mixing and possible various
combination of CP violating Majorana phases effects the neutrino mass
eigenvalues. We have considered the effective Majorana mass m_{e}, related for
\,\left(\beta\beta\right)_{0\nu\,} decay. In calculation, we consider two
different neutrino mass orders, normal and inverted. We find the limits for
neutrino mass eigenvalue m_{i} in the different neutrino mass spectrum and the
sum of all four neutrino masses is
\text{{\Sigma}}\text{\ensuremath{\equiv}}m_{1}+m_{2}+m_{3}+m_{4}>1.3\,eV\,
which is relevant for cosmological observations and explain the different
neutrino oscillations data.
| [
{
"created": "Tue, 8 Jun 2021 03:20:47 GMT",
"version": "v1"
},
{
"created": "Sat, 12 Jun 2021 11:41:44 GMT",
"version": "v2"
}
] | 2021-06-15 | [
[
"Nautiyal",
"Vivek Kumar",
""
],
[
"Koranga",
"Bipin Singh",
""
],
[
"Singh",
"Jaydip",
""
]
] | In this paper, we discuss neutrino mass eigenvalues for four flavor neutrino mixing. An extra mass states, in four flavor mixing and possible various combination of CP violating Majorana phases effects the neutrino mass eigenvalues. We have considered the effective Majorana mass m_{e}, related for \,\left(\beta\beta\right)_{0\nu\,} decay. In calculation, we consider two different neutrino mass orders, normal and inverted. We find the limits for neutrino mass eigenvalue m_{i} in the different neutrino mass spectrum and the sum of all four neutrino masses is \text{{\Sigma}}\text{\ensuremath{\equiv}}m_{1}+m_{2}+m_{3}+m_{4}>1.3\,eV\, which is relevant for cosmological observations and explain the different neutrino oscillations data. |
hep-ph/0203114 | Jonathan R. Ellis | John Ellis (CERN) | Supersymmetry for Alp Hikers | 45 pages, 19 figures, Lectures at the European School of High-Energy
Physics, Beatenberg, Switzerland, 26 Aug - 8 Sept 2001 | null | null | CERN-TH/2002-052 | hep-ph | null | These lectures provide a phenomenological introduction to supersymmetry,
concentrating on the minimal supersymmetric extension of the Standard Model
(MSSM). In the first lecture, motivations are provided for thinking that
supersymmetry might appear at the TeV scale, including the naturalness of the
mass hierarchy, gauge unification and the probable mass of the Higgs boson. In
the second lecture, simple globally supersymmetric field theories are
introduced, with the emphasis on features important for model-building.
Supersymmetry breaking and local supersymmetry (supergravity) are introduced in
the third lecture, and the structure of sparticle mass matrices and mixing are
reviewed. Finally, the available experimental and cosmological constraints on
MSSM parameters are discussed and combined in the fourth lecture, and the
prospects for discovering supersymmetry in future experiments are previewed.
| [
{
"created": "Wed, 13 Mar 2002 10:56:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ellis",
"John",
"",
"CERN"
]
] | These lectures provide a phenomenological introduction to supersymmetry, concentrating on the minimal supersymmetric extension of the Standard Model (MSSM). In the first lecture, motivations are provided for thinking that supersymmetry might appear at the TeV scale, including the naturalness of the mass hierarchy, gauge unification and the probable mass of the Higgs boson. In the second lecture, simple globally supersymmetric field theories are introduced, with the emphasis on features important for model-building. Supersymmetry breaking and local supersymmetry (supergravity) are introduced in the third lecture, and the structure of sparticle mass matrices and mixing are reviewed. Finally, the available experimental and cosmological constraints on MSSM parameters are discussed and combined in the fourth lecture, and the prospects for discovering supersymmetry in future experiments are previewed. |
2301.08961 | Anatoly Kotikov Vassilievich | N.A. Abdulov, A.V. Kotikov, A.V. Lipatov | On x-independence of RQ = FLQ/F2Q ratio at low x | 10 pages, 3 figures, | null | 10.1134/S002136402360012X | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give predictions for the ratio RQ(x,Q2)=FLQ(x,Q2)/F2Q(x,Q2) at small
values of Bjorken variable x in the first three orders of perturbation theory.
We show an approximate x-independence of RQ(x,Q2) at low x and non-large Q2
values (Q2 < 8--10 m2Q), irrespectively on the gluon density in a proton used
in the calculations. This observation could be useful in subsequent
phenomenological studies of the heavy flavor production at future lepton-hadron
and hadron-hadron colliders.
| [
{
"created": "Sat, 21 Jan 2023 15:09:39 GMT",
"version": "v1"
}
] | 2023-03-29 | [
[
"Abdulov",
"N. A.",
""
],
[
"Kotikov",
"A. V.",
""
],
[
"Lipatov",
"A. V.",
""
]
] | We give predictions for the ratio RQ(x,Q2)=FLQ(x,Q2)/F2Q(x,Q2) at small values of Bjorken variable x in the first three orders of perturbation theory. We show an approximate x-independence of RQ(x,Q2) at low x and non-large Q2 values (Q2 < 8--10 m2Q), irrespectively on the gluon density in a proton used in the calculations. This observation could be useful in subsequent phenomenological studies of the heavy flavor production at future lepton-hadron and hadron-hadron colliders. |
1012.6007 | Yu Jia | Yu Jia, Jian-Xiong Wang, Deshan Yang | Bridging light-cone and NRQCD approaches: asymptotic behavior of $B_c$
electromagnetic form factor | v3, 39 pages, 5 figures. A minor error in equation (37) corrected,
Fig. 4 redrawn. A new paragraph added to discuss the numerical significance
of double logarithm term in O(alpha_s) short-distane coefficient for
gamma*->J/psi+eta_c process, and one reference added | null | 10.1007/JHEP10(2011)105 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This work aims at illustrating that, for a class of leading-twist hard
exclusive reactions involving two heavy quarkonia, the light-cone approach,
when equipped with the strategy of refactorization of the light-cone
distribution amplitude of quarkonium, can be employed to elegantly reproduce
the corresponding predictions made in the nonrelativistic QCD (NRQCD)
factorization approach, order by order in perturbative expansion. Taking the
electromagnetic form factor of the $B_c$ meson at large momentum transfer,
$Q^2$, as a concrete example, we compare the results obtained from both
NRQCD-based and light-cone-based calculations through the next-to-leading order
(NLO) in $\alpha_s$, while at the leading order (LO) in both velocity and
$1/Q^2$ expansion, and explicitly confirm their mutual agreement. As a
byproduct, we apply our NLO result to explore certain features about the
asymptotic behavior of the heavy-light meson form factor. We also address the
major theoretical obstacles that prevent us from establishing an analogous
equivalence between these two approaches for the double charmonium production
process of phenomenological interest, $e^+e^-\to J/\psi+\eta_c$.
| [
{
"created": "Wed, 29 Dec 2010 19:18:14 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Mar 2011 14:55:01 GMT",
"version": "v2"
},
{
"created": "Wed, 31 Aug 2011 14:47:22 GMT",
"version": "v3"
}
] | 2015-05-20 | [
[
"Jia",
"Yu",
""
],
[
"Wang",
"Jian-Xiong",
""
],
[
"Yang",
"Deshan",
""
]
] | This work aims at illustrating that, for a class of leading-twist hard exclusive reactions involving two heavy quarkonia, the light-cone approach, when equipped with the strategy of refactorization of the light-cone distribution amplitude of quarkonium, can be employed to elegantly reproduce the corresponding predictions made in the nonrelativistic QCD (NRQCD) factorization approach, order by order in perturbative expansion. Taking the electromagnetic form factor of the $B_c$ meson at large momentum transfer, $Q^2$, as a concrete example, we compare the results obtained from both NRQCD-based and light-cone-based calculations through the next-to-leading order (NLO) in $\alpha_s$, while at the leading order (LO) in both velocity and $1/Q^2$ expansion, and explicitly confirm their mutual agreement. As a byproduct, we apply our NLO result to explore certain features about the asymptotic behavior of the heavy-light meson form factor. We also address the major theoretical obstacles that prevent us from establishing an analogous equivalence between these two approaches for the double charmonium production process of phenomenological interest, $e^+e^-\to J/\psi+\eta_c$. |
1811.11720 | Gudrun Heinrich | S.Borowka, G.Heinrich, S.Jahn, S.P.Jones, M.Kerner, J.Schlenk | A GPU compatible quasi-Monte Carlo integrator interfaced to pySecDec | 44 pages, 14 figures; v2: Eq.(22) corrected, matches published
version | Comput.Phys.Commun. 240 (2019) 120 | 10.1016/j.cpc.2019.02.015 | CERN-TH-2018-246, MPP-2018-279, ZU-TH 43/18, IPPP/18/100 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The purely numerical evaluation of multi-loop integrals and amplitudes can be
a viable alternative to analytic approaches, in particular in the presence of
several mass scales, provided sufficient accuracy can be achieved in an
acceptable amount of time. For many multi-loop integrals, the fraction of time
required to perform the numerical integration is significant and it is
therefore beneficial to have efficient and well-implemented numerical
integration methods. With this goal in mind, we present a new stand-alone
integrator based on the use of (quasi-Monte Carlo) rank-1 shifted lattice
rules. For integrals with high variance we also implement a variance reduction
algorithm based on fitting a smooth function to the inverse cumulative
distribution function of the integrand dimension-by-dimension. Additionally,
the new integrator is interfaced to pySecDec to allow the straightforward
evaluation of multi-loop integrals and dimensionally regulated parameter
integrals. In order to make use of recent advances in parallel computing
hardware, our integrator can be used both on CPUs and CUDA compatible GPUs
where available.
| [
{
"created": "Wed, 28 Nov 2018 18:17:44 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Jun 2019 17:40:08 GMT",
"version": "v2"
}
] | 2019-06-26 | [
[
"Borowka",
"S.",
""
],
[
"Heinrich",
"G.",
""
],
[
"Jahn",
"S.",
""
],
[
"Jones",
"S. P.",
""
],
[
"Kerner",
"M.",
""
],
[
"Schlenk",
"J.",
""
]
] | The purely numerical evaluation of multi-loop integrals and amplitudes can be a viable alternative to analytic approaches, in particular in the presence of several mass scales, provided sufficient accuracy can be achieved in an acceptable amount of time. For many multi-loop integrals, the fraction of time required to perform the numerical integration is significant and it is therefore beneficial to have efficient and well-implemented numerical integration methods. With this goal in mind, we present a new stand-alone integrator based on the use of (quasi-Monte Carlo) rank-1 shifted lattice rules. For integrals with high variance we also implement a variance reduction algorithm based on fitting a smooth function to the inverse cumulative distribution function of the integrand dimension-by-dimension. Additionally, the new integrator is interfaced to pySecDec to allow the straightforward evaluation of multi-loop integrals and dimensionally regulated parameter integrals. In order to make use of recent advances in parallel computing hardware, our integrator can be used both on CPUs and CUDA compatible GPUs where available. |
2305.14446 | Sarunas Verner | Marcos A. G. Garcia, Mathias Pierre, Sarunas Verner | A New Window into Gravitationally Produced Scalar Dark Matter | 9 pages, 3 figures (Supplementary Material: 14 pages, 6 figures);
Published version | null | null | DESY-23-065 | hep-ph astro-ph.CO gr-qc | http://creativecommons.org/licenses/by/4.0/ | Conventional scenarios of purely gravitationally produced dark matter with
masses below the Hubble parameter at the end of inflation are in tension with
Cosmic Microwave Background (CMB) constraints on the isocurvature power
spectrum. We explore a more general scenario with a non-minimal coupling
between the scalar dark matter field and gravity, which allows for
significantly lighter scalar dark matter masses compared to minimal coupling
predictions. By imposing relic abundance, isocurvature, Lyman-$\alpha$, and Big
Bang Nucleosynthesis (BBN) constraints, we show the viable parameter space for
these models. Our findings demonstrate that the presence of a non-minimal
coupling expands the parameter space, yielding a dark matter mass lower bound
of $2 \times 10^{-4} \, \rm{eV}$.
| [
{
"created": "Tue, 23 May 2023 18:10:23 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Jun 2023 14:57:17 GMT",
"version": "v2"
},
{
"created": "Wed, 14 Feb 2024 14:44:24 GMT",
"version": "v3"
}
] | 2024-02-15 | [
[
"Garcia",
"Marcos A. G.",
""
],
[
"Pierre",
"Mathias",
""
],
[
"Verner",
"Sarunas",
""
]
] | Conventional scenarios of purely gravitationally produced dark matter with masses below the Hubble parameter at the end of inflation are in tension with Cosmic Microwave Background (CMB) constraints on the isocurvature power spectrum. We explore a more general scenario with a non-minimal coupling between the scalar dark matter field and gravity, which allows for significantly lighter scalar dark matter masses compared to minimal coupling predictions. By imposing relic abundance, isocurvature, Lyman-$\alpha$, and Big Bang Nucleosynthesis (BBN) constraints, we show the viable parameter space for these models. Our findings demonstrate that the presence of a non-minimal coupling expands the parameter space, yielding a dark matter mass lower bound of $2 \times 10^{-4} \, \rm{eV}$. |
2204.05965 | Motoi Endo | Motoi Endo, Satoshi Mishima | New physics interpretation of $W$-boson mass anomaly | 20 pages, 4 figures, version accepted by PRD | null | 10.1103/PhysRevD.106.115005 | KEK-TH-2412 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The CDF collaboration has recently reported an updated result on the
$W$-boson mass measurement, showing a $7\sigma$ deviation from the standard
model prediction. The discrepancy may indicate new contributions to the Fermi
coupling constant. We study simple extensions of the standard model by
introducing an extra scalar, fermion or vector field. It is found that the
tension implies the new physics existing in multi-TeV scales if the new
coupling to the electron and/or muon is of order unity.
| [
{
"created": "Tue, 12 Apr 2022 17:27:47 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Apr 2022 04:06:35 GMT",
"version": "v2"
},
{
"created": "Thu, 9 Jun 2022 10:42:20 GMT",
"version": "v3"
},
{
"created": "Tue, 29 Nov 2022 04:12:43 GMT",
"version": "v4"
}
] | 2022-12-21 | [
[
"Endo",
"Motoi",
""
],
[
"Mishima",
"Satoshi",
""
]
] | The CDF collaboration has recently reported an updated result on the $W$-boson mass measurement, showing a $7\sigma$ deviation from the standard model prediction. The discrepancy may indicate new contributions to the Fermi coupling constant. We study simple extensions of the standard model by introducing an extra scalar, fermion or vector field. It is found that the tension implies the new physics existing in multi-TeV scales if the new coupling to the electron and/or muon is of order unity. |
1906.11119 | Wim Cosyn | W. Cosyn, C. Weiss | Neutron spin structure from polarized deuteron DIS with proton tagging | 7 pages, 3 figures. Revised published version; minor additions in the
text | Physics Letters B799 (2019), 135035 | 10.1016/j.physletb.2019.135035 | JLAB-THY-19-2967 | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Polarized electron-deuteron deep-inelastic scattering (DIS) with detection of
the spectator proton ("tagged DIS") enables measurements of neutron spin
structure with maximal control of nuclear effects. We calculate the
longitudinal spin asymmetries in polarized tagged DIS using methods of
light-front nuclear structure and study their dependence on the measured proton
momentum. Asymmetries can be formed with all three deuteron spin states ($\pm
1, 0$) or the two maximum-spin states only ($\pm 1$, involving tensor
polarization). The proton momentum dependence can be used to select pure S-wave
configurations in the deuteron and eliminate D-wave depolarization (transverse
momenta $p_{pT} \lesssim$ 100 MeV). Free neutron spin structure can be
extracted model-independently through pole extrapolation of the tagged
asymmetries. Such measurements could be performed at a future electron-ion
collider (EIC) with polarized deuteron beams and forward proton detectors.
| [
{
"created": "Wed, 26 Jun 2019 14:24:38 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Nov 2019 00:09:44 GMT",
"version": "v2"
}
] | 2019-11-15 | [
[
"Cosyn",
"W.",
""
],
[
"Weiss",
"C.",
""
]
] | Polarized electron-deuteron deep-inelastic scattering (DIS) with detection of the spectator proton ("tagged DIS") enables measurements of neutron spin structure with maximal control of nuclear effects. We calculate the longitudinal spin asymmetries in polarized tagged DIS using methods of light-front nuclear structure and study their dependence on the measured proton momentum. Asymmetries can be formed with all three deuteron spin states ($\pm 1, 0$) or the two maximum-spin states only ($\pm 1$, involving tensor polarization). The proton momentum dependence can be used to select pure S-wave configurations in the deuteron and eliminate D-wave depolarization (transverse momenta $p_{pT} \lesssim$ 100 MeV). Free neutron spin structure can be extracted model-independently through pole extrapolation of the tagged asymmetries. Such measurements could be performed at a future electron-ion collider (EIC) with polarized deuteron beams and forward proton detectors. |
1110.0239 | Gilles Henri | Gilles Henri | A simple explanation of OPERA results without strange physics | 5 pages, 1 figure | null | null | null | hep-ph astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that OPERA recent results showing an apparent superluminal velocity
of muonic neutrinos can find a very simple explanation without any measurement
error or any strange physics. Namely, it is enough that the beam composition
varies during the leading and the trailing edges to explain an apparent time
shift in the detected neutrinos. The order of magnitude of the shift will be
the relative variation of the average cross-section times the rising/decaying
time, and even a modest change in the composition of the beam could produce the
observed effect.
| [
{
"created": "Sun, 2 Oct 2011 22:18:10 GMT",
"version": "v1"
}
] | 2011-10-04 | [
[
"Henri",
"Gilles",
""
]
] | We show that OPERA recent results showing an apparent superluminal velocity of muonic neutrinos can find a very simple explanation without any measurement error or any strange physics. Namely, it is enough that the beam composition varies during the leading and the trailing edges to explain an apparent time shift in the detected neutrinos. The order of magnitude of the shift will be the relative variation of the average cross-section times the rising/decaying time, and even a modest change in the composition of the beam could produce the observed effect. |
1009.4869 | Hisakazu Minakata | Hisakazu Minakata and Carlos Pena-Garay | Solar Neutrino Observables Sensitive to Matter Effects | 15 pages, 1 figure. to be published in Special Issue on Neutrino
Physics, Advances in High Energy Physics Hindawi Publishing Corporation 2012 | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss constraints on the coefficient A_{MSW} which is introduced to
simulate the effect of weaker or stronger matter potential for electron
neutrinos with the current and future solar neutrino data. The currently
available solar neutrino data leads to a bound A_{MSW} = 1.47^{-0.42}_{+0.54}
(^{-0.82}_{+1.88}) at 1\sigma (3\sigma) CL, which is consistent with the
Standard Model prediction A_{MSW} = 1. For weaker matter potential (A_{MSW} <
1), the constraint which comes from the flat ^8B neutrino spectrum is already
very tight, indicating the evidence for matter effects. Whereas for stronger
matter potential (A_{MSW} > 1), the bound is milder and is dominated by the
day-night asymmetry of ^8B neutrino flux recently observed by Super-Kamiokande.
Among the list of observable of ongoing and future solar neutrino experiments,
we find that (1) an improved precision of the day-night asymmetry of ^8B
neutrinos, (2) precision measurements of the low energy quasi-monoenergetic
neutrinos, and (3) the detection of the upturn of the ^8B neutrino spectrum at
low energies, are the best choices to improve the bound on A_{MSW}.
| [
{
"created": "Fri, 24 Sep 2010 15:34:33 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Aug 2012 15:13:02 GMT",
"version": "v2"
},
{
"created": "Tue, 2 Oct 2012 04:03:40 GMT",
"version": "v3"
}
] | 2012-10-03 | [
[
"Minakata",
"Hisakazu",
""
],
[
"Pena-Garay",
"Carlos",
""
]
] | We discuss constraints on the coefficient A_{MSW} which is introduced to simulate the effect of weaker or stronger matter potential for electron neutrinos with the current and future solar neutrino data. The currently available solar neutrino data leads to a bound A_{MSW} = 1.47^{-0.42}_{+0.54} (^{-0.82}_{+1.88}) at 1\sigma (3\sigma) CL, which is consistent with the Standard Model prediction A_{MSW} = 1. For weaker matter potential (A_{MSW} < 1), the constraint which comes from the flat ^8B neutrino spectrum is already very tight, indicating the evidence for matter effects. Whereas for stronger matter potential (A_{MSW} > 1), the bound is milder and is dominated by the day-night asymmetry of ^8B neutrino flux recently observed by Super-Kamiokande. Among the list of observable of ongoing and future solar neutrino experiments, we find that (1) an improved precision of the day-night asymmetry of ^8B neutrinos, (2) precision measurements of the low energy quasi-monoenergetic neutrinos, and (3) the detection of the upturn of the ^8B neutrino spectrum at low energies, are the best choices to improve the bound on A_{MSW}. |
hep-ph/0507121 | De-Min Li | De-Min Li, Ke-Wei Wei, Hong Yu | A possible assignment for the ground scalar meson nonet | 10 pages, to appear in Eur. Phys. J. A | Eur.Phys.J.A25:263-266,2005 | 10.1140/epja/i2005-10091-5 | null | hep-ph | null | Based on the main assumption that the $a_0(980)$ and $D^\ast_{sJ}(2317)$
belong to the $1 ^3P_0$ $q\bar{q}$ multiplet, in the framework of Regge
phenomenology and meson-meson mixing, it is suggested that the $a_0(980)$,
$K^\ast_0(1052)$, $f_0(1099)$ and $f_0(530)$ constitute the ground scalar meson
nonet, and that the $f_0(1099)$ is composed mostly of $s\bar{s}$ while the
$f_0(530)$ is mainly $u\bar{u}+d\bar{d}$. It is supposed that these states
would likely correspond to the observed scalar states $a_0(980)$,
$\kappa(900)$,
$f_0(980)$ and $f_0(600)/\sigma$, respectively. The agreement between the
present findings and those given by other different approaches is satisfactory.
| [
{
"created": "Mon, 11 Jul 2005 04:02:36 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Li",
"De-Min",
""
],
[
"Wei",
"Ke-Wei",
""
],
[
"Yu",
"Hong",
""
]
] | Based on the main assumption that the $a_0(980)$ and $D^\ast_{sJ}(2317)$ belong to the $1 ^3P_0$ $q\bar{q}$ multiplet, in the framework of Regge phenomenology and meson-meson mixing, it is suggested that the $a_0(980)$, $K^\ast_0(1052)$, $f_0(1099)$ and $f_0(530)$ constitute the ground scalar meson nonet, and that the $f_0(1099)$ is composed mostly of $s\bar{s}$ while the $f_0(530)$ is mainly $u\bar{u}+d\bar{d}$. It is supposed that these states would likely correspond to the observed scalar states $a_0(980)$, $\kappa(900)$, $f_0(980)$ and $f_0(600)/\sigma$, respectively. The agreement between the present findings and those given by other different approaches is satisfactory. |
0807.1238 | Andreas Vogt | A. Vogt (Liverpool Univ), S. Moch, M. Rogal (DESY, Zeuthen), J.A.M.
Vermaseren (NIKHEF, Amsterdam) | Towards the NNLO evolution of polarised parton distributions | 7 pages, LaTeX, 4 ps/eps-figures. Contribution to the proceedings of
the workshops `Loops and Legs in Quantum Field Theory', April 2008,
Sondershausen (Germany) and (shortened) DIS 2008, London, April 2008 | Nucl.Phys.Proc.Suppl.183:155-161,2008 | 10.1016/j.nuclphysbps.2008.09.097 | LTH 795, DESY 08-092 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on the first calculation of the structure function g_1 in polarised
deep-inelastic scattering to the third order in massless perturbative QCD. The
calculation follows the dispersive approach already used for the corresponding
unpolarised cases of F_2,L, but additionally involves higher tensor integrals
and the Dirac matrix gamma_5 in D unequal 4 dimensions. Our results confirm all
known two-loop expressions including the coefficient functions of Zijlstra and
van Neerven not independently verified before. At three loops we extract the
helicity-difference next-to-next-to-leading order (NNLO) quark-quark and
gluon-quark splitting functions Delta P_qq and Delta P_qg. The results exhibit
interesting features concerning sum rules and the momentum-fraction limits x to
1 and x to 0.
| [
{
"created": "Tue, 8 Jul 2008 13:31:54 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Vogt",
"A.",
"",
"Liverpool Univ"
],
[
"Moch",
"S.",
"",
"DESY, Zeuthen"
],
[
"Rogal",
"M.",
"",
"DESY, Zeuthen"
],
[
"Vermaseren",
"J. A. M.",
"",
"NIKHEF, Amsterdam"
]
] | We report on the first calculation of the structure function g_1 in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding unpolarised cases of F_2,L, but additionally involves higher tensor integrals and the Dirac matrix gamma_5 in D unequal 4 dimensions. Our results confirm all known two-loop expressions including the coefficient functions of Zijlstra and van Neerven not independently verified before. At three loops we extract the helicity-difference next-to-next-to-leading order (NNLO) quark-quark and gluon-quark splitting functions Delta P_qq and Delta P_qg. The results exhibit interesting features concerning sum rules and the momentum-fraction limits x to 1 and x to 0. |
hep-ph/9704324 | Brian W. Harris | B.W. Harris and J.F. Owens | Photoproduction of jets at HERA in next-to-leading order QCD | 16 pages, Latex, uses Revtex and psfig macros. References added.
Discussion of dijet production extended. Submitted to Phys. Rev. D | Phys.Rev.D56:4007-4016,1997 | 10.1103/PhysRevD.56.4007 | FSU-HEP-970411 | hep-ph | null | A new next-to-leading order Monte Carlo program for the calculation of jet
cross sections in photoproduction is described. The contributions from both
resolved and direct components are included to O(\alpha \alpha_s^2). Properties
of the predictions for various inclusive jet and dijet observables are
discussed and comparisons with HERA data are presented.
| [
{
"created": "Mon, 14 Apr 1997 22:06:56 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Jun 1997 20:45:13 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Harris",
"B. W.",
""
],
[
"Owens",
"J. F.",
""
]
] | A new next-to-leading order Monte Carlo program for the calculation of jet cross sections in photoproduction is described. The contributions from both resolved and direct components are included to O(\alpha \alpha_s^2). Properties of the predictions for various inclusive jet and dijet observables are discussed and comparisons with HERA data are presented. |
hep-ph/0310282 | Enrico Lunghi | T. Hurth (CERN, SLAC), E. Lunghi (Zurich), W. Porod (Zurich) | Updated NLL Results for B -> (Xs,Xd) gamma in and beyond the SM | 3 pages, Contribution to the International Europhysics Conference on
High Energy Physics EPS03, 17-23 July 2003, Aachen, Germany, minor changes | Eur.Phys.J.C33:s382-s384,2004 | 10.1140/epjcd/s2003-03-318-7 | CERN-TH/2003-251, SLAC-PUB-10210, ZU-TH 17/03 | hep-ph | null | We present general model-independent formulae for the branching ratios and
the direct tagged CP asymmetries for the inclusive B -> Xd gamma and B -> Xs
gamma modes. We also update the corresponding SM predictions.
| [
{
"created": "Thu, 23 Oct 2003 23:59:16 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Nov 2003 20:03:01 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Hurth",
"T.",
"",
"CERN, SLAC"
],
[
"Lunghi",
"E.",
"",
"Zurich"
],
[
"Porod",
"W.",
"",
"Zurich"
]
] | We present general model-independent formulae for the branching ratios and the direct tagged CP asymmetries for the inclusive B -> Xd gamma and B -> Xs gamma modes. We also update the corresponding SM predictions. |
1306.4314 | John Kearney | John Kearney, Aaron Pierce and Jesse Thaler | Exotic Top Partners and Little Higgs | 27 pages, 2 figures, 4 tables; v3: JHEP revision -- updated to
include discussion of naturalness and section 2.1 expanded | null | 10.1007/JHEP10(2013)230 | MCTP-13-17, MIT-CTP 4470 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Little Higgs models often give rise to top partners beyond the minimal ones
necessary for the cancellation of quadratic divergences. We review how this
occurs and discuss the phenomenology of these exotic states. We emphasize the
possible importance of new pseudo-Nambu-Goldstone bosons in top partner decays.
Indeed, cascade decays of exotic top partners may be the best way to discover
these new bosons. We illustrate these points with a new Little Higgs
construction based on an SO(10)/SO(5)^2 coset structure, which fills a gap in
the model building literature. These observations motivate new search
strategies for top partners at the LHC, including for final states with b-jets
and a large multiplicity of electroweak bosons.
| [
{
"created": "Tue, 18 Jun 2013 20:00:00 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Jul 2013 18:27:05 GMT",
"version": "v2"
},
{
"created": "Fri, 4 Oct 2013 14:03:08 GMT",
"version": "v3"
}
] | 2015-06-16 | [
[
"Kearney",
"John",
""
],
[
"Pierce",
"Aaron",
""
],
[
"Thaler",
"Jesse",
""
]
] | Little Higgs models often give rise to top partners beyond the minimal ones necessary for the cancellation of quadratic divergences. We review how this occurs and discuss the phenomenology of these exotic states. We emphasize the possible importance of new pseudo-Nambu-Goldstone bosons in top partner decays. Indeed, cascade decays of exotic top partners may be the best way to discover these new bosons. We illustrate these points with a new Little Higgs construction based on an SO(10)/SO(5)^2 coset structure, which fills a gap in the model building literature. These observations motivate new search strategies for top partners at the LHC, including for final states with b-jets and a large multiplicity of electroweak bosons. |
1910.12654 | Aleksandra Lelek | Aleksandra Lelek | Angular ordering effects in TMD parton distribution functions and
Drell-Yan $q_{\bot}$ spectra | 4 pages, 3 figures | 54th Rencontres de Moriond on QCD and High Energy Interactions
(Moriond QCD 2019) | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present new results of our studies of soft-gluon angular ordering effects
on the evolution of both collinear and transverse momentum dependent (TMD)
parton distribution functions, and discuss their implications for precision
predictions of Drell-Yan transverse momentum spectra at the LHC. Our method is
based on the parton branching (PB) approach. We compare this with the
implementation of angular ordering in the Kimber-Martin-Ryskin-Watt (KMRW)
approach and with the Collins-Soper-Sterman (CSS) approach. We illustrate
numerically the effects of different ordering scenarios ($p_{\bot}$, angular
ordering), including definitions of the soft-gluon resolution scale and scale
in the running coupling, on the theoretical accuracy of predictions in the low
transverse momentum region of Drell-Yan spectra measured at the LHC.
| [
{
"created": "Mon, 28 Oct 2019 13:22:57 GMT",
"version": "v1"
}
] | 2019-10-29 | [
[
"Lelek",
"Aleksandra",
""
]
] | We present new results of our studies of soft-gluon angular ordering effects on the evolution of both collinear and transverse momentum dependent (TMD) parton distribution functions, and discuss their implications for precision predictions of Drell-Yan transverse momentum spectra at the LHC. Our method is based on the parton branching (PB) approach. We compare this with the implementation of angular ordering in the Kimber-Martin-Ryskin-Watt (KMRW) approach and with the Collins-Soper-Sterman (CSS) approach. We illustrate numerically the effects of different ordering scenarios ($p_{\bot}$, angular ordering), including definitions of the soft-gluon resolution scale and scale in the running coupling, on the theoretical accuracy of predictions in the low transverse momentum region of Drell-Yan spectra measured at the LHC. |
1405.7103 | Zhenjun Xiao | Ya-Lan Zhang, Xue-Yan Liu, Ying-Ying Fan, Shan Cheng, and Zhen-Jun
Xiao | $B\to \pi\pi$ decays and effects of the next-to-leading order
contributions | 11 pages, 1 figure | Phys. Rev. D 90, 014029 (2014) | 10.1103/PhysRevD.90.014029 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we perform a systematic study for the three $B \to
(\pi^+\pi^-,\pi^+\pi^0,\pi^0\pi^0)$ decays in the perturbative QCD (pQCD)
factorization approach with the inclusion of all currently known
next-to-leading order (NLO) contributions from various sources. We found that
(a) for the CP-averaged decay rates $Br(B^0\to \pi^+\pi^-)$ and $Br(B^+\to
\pi^+\pi^0)$, the NLO pQCD predictions agree with the data within one standard
dviation; (b) for $Br(B^0\to \pi^0\pi^0)$, however, although the NLO
contributions can provide a $\sim 100\%$ enhancement to the leading order (LO)
result, it is still not large enough to interpret the data; (c) for the
CP-violating asymmetries of $B^0\to \pi^+\pi^-$ decay, the central values of
the NLO PQCD predictions agree with the data; and (d) we also examined the
relative strength of the LO and NLO contributions from different sources.
| [
{
"created": "Wed, 28 May 2014 02:29:33 GMT",
"version": "v1"
}
] | 2014-07-23 | [
[
"Zhang",
"Ya-Lan",
""
],
[
"Liu",
"Xue-Yan",
""
],
[
"Fan",
"Ying-Ying",
""
],
[
"Cheng",
"Shan",
""
],
[
"Xiao",
"Zhen-Jun",
""
]
] | In this paper we perform a systematic study for the three $B \to (\pi^+\pi^-,\pi^+\pi^0,\pi^0\pi^0)$ decays in the perturbative QCD (pQCD) factorization approach with the inclusion of all currently known next-to-leading order (NLO) contributions from various sources. We found that (a) for the CP-averaged decay rates $Br(B^0\to \pi^+\pi^-)$ and $Br(B^+\to \pi^+\pi^0)$, the NLO pQCD predictions agree with the data within one standard dviation; (b) for $Br(B^0\to \pi^0\pi^0)$, however, although the NLO contributions can provide a $\sim 100\%$ enhancement to the leading order (LO) result, it is still not large enough to interpret the data; (c) for the CP-violating asymmetries of $B^0\to \pi^+\pi^-$ decay, the central values of the NLO PQCD predictions agree with the data; and (d) we also examined the relative strength of the LO and NLO contributions from different sources. |
hep-ph/0309229 | Ilya Narodetskii | I.M.Narodetskii | Selected Theoretical Issues in B-meson Physics: CKM matrix and
Semileptonic Decays | 44 pages, 13 figures, LATeX2e, Axodraw package used; Submitted to
"Survey in High Energy Physics" | Surveys High Energ.Phys.19:1-34,2004 | 10.1080/0142241042000210782 | null | hep-ph | null | These notes are a written version of a lecture given at the International
Seminar {\it Modern Trends and Classical Approach} devoted to the 80$^{th}$
anniversary of Prof. Karen Ter-Martirosyan, ITEP September 30 -- October 1,
2002. The notes represent a non-technical review of our present knowledge on
the phenomenology of weak decays of quarks, and their r\^ole in the
determination of the parameters of the Standard Model. They are meant as an
introduction to some of the latest results and applications in the field.
Specifically, we focus on CP violation in B-decays and the determination of the
CKM matrix element $V_{cb}$ from semileptonic decays of $B$ mesons. We also
briefly discuss phenomenological applications concerning the electron-energy
spectra in semileptonic $B$ and $B_c$ decays.
| [
{
"created": "Fri, 19 Sep 2003 11:36:14 GMT",
"version": "v1"
}
] | 2010-12-09 | [
[
"Narodetskii",
"I. M.",
""
]
] | These notes are a written version of a lecture given at the International Seminar {\it Modern Trends and Classical Approach} devoted to the 80$^{th}$ anniversary of Prof. Karen Ter-Martirosyan, ITEP September 30 -- October 1, 2002. The notes represent a non-technical review of our present knowledge on the phenomenology of weak decays of quarks, and their r\^ole in the determination of the parameters of the Standard Model. They are meant as an introduction to some of the latest results and applications in the field. Specifically, we focus on CP violation in B-decays and the determination of the CKM matrix element $V_{cb}$ from semileptonic decays of $B$ mesons. We also briefly discuss phenomenological applications concerning the electron-energy spectra in semileptonic $B$ and $B_c$ decays. |
1706.04809 | Pietro Colangelo | L. Bellantuono, P. Colangelo, F. De Fazio, F. Giannuzzi, S. Nicotri | Quarkonium dissociation in a far-from-equilibrium holographic setup | 14 pages, 8 figures. References added. Matches the published version | Phys. Rev. D 96, 034031 (2017) | 10.1103/PhysRevD.96.034031 | BARI-TH/2017-711 | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The real-time dissociation of the heavy quarkonium in a strongly coupled
boost-invariant non-Abelian plasma relaxing towards equilibrium is analyzed in
a holographic framework. The effects driving the plasma out of equilibrium are
described by boundary quenching, impulsive variations of the boundary metric.
Quarkonium is represented by a classical string with endpoints kept close to
the boundary. The evolution of the string profile is computed in the
time-dependent geometry, and the dissociation time is evaluated for different
configurations with respect to the direction of the plasma expansion.
Dissociation occurs fastly for the quarkonium placed in the transverse plane.
| [
{
"created": "Thu, 15 Jun 2017 10:44:29 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Sep 2017 10:54:42 GMT",
"version": "v2"
}
] | 2017-09-08 | [
[
"Bellantuono",
"L.",
""
],
[
"Colangelo",
"P.",
""
],
[
"De Fazio",
"F.",
""
],
[
"Giannuzzi",
"F.",
""
],
[
"Nicotri",
"S.",
""
]
] | The real-time dissociation of the heavy quarkonium in a strongly coupled boost-invariant non-Abelian plasma relaxing towards equilibrium is analyzed in a holographic framework. The effects driving the plasma out of equilibrium are described by boundary quenching, impulsive variations of the boundary metric. Quarkonium is represented by a classical string with endpoints kept close to the boundary. The evolution of the string profile is computed in the time-dependent geometry, and the dissociation time is evaluated for different configurations with respect to the direction of the plasma expansion. Dissociation occurs fastly for the quarkonium placed in the transverse plane. |
1212.6134 | Sarbani Majumder | Abhijit Bhattacharyya (1), Sanjay K. Ghosh (2), Anirban Lahiri (2),
Sarbani Majumder (2), Sibaji Raha (2), Rajarshi Ray (2) ((1) University of
Calcutta, Kolkata, India, (2) Bose Institute, Kolkata, India) | Isospin symmetry breaking and baryon-isospin correlations from
Polyakov$-$Nambu$-$Jona-Lasinio model | null | Phys. Rev. C.89, 064905 (2014) | 10.1103/PhysRevC.89.064905 | null | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a study of the 1+1 flavor system of strongly interacting matter in
terms of the Polyakov$-$Nambu$-$Jona-Lasinio model. We find that though the
small isospin symmetry breaking brought in through unequal light quark masses
is too small to affect the thermodynamics of the system in general, it may have
significant effect in baryon-isospin correlations and have a measurable impact
in heavy-ion collision experiments.
| [
{
"created": "Wed, 26 Dec 2012 08:25:10 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Jun 2014 05:55:25 GMT",
"version": "v2"
}
] | 2014-06-12 | [
[
"Bhattacharyya",
"Abhijit",
""
],
[
"Ghosh",
"Sanjay K.",
""
],
[
"Lahiri",
"Anirban",
""
],
[
"Majumder",
"Sarbani",
""
],
[
"Raha",
"Sibaji",
""
],
[
"Ray",
"Rajarshi",
""
]
] | We present a study of the 1+1 flavor system of strongly interacting matter in terms of the Polyakov$-$Nambu$-$Jona-Lasinio model. We find that though the small isospin symmetry breaking brought in through unequal light quark masses is too small to affect the thermodynamics of the system in general, it may have significant effect in baryon-isospin correlations and have a measurable impact in heavy-ion collision experiments. |
2212.01268 | Amin Aboubrahim | Amin Aboubrahim, Mohammad Mahdi Altakach, Michael Klasen, Pran Nath
and Zhu-Yao Wang | Combined constraints on dark photons and discovery prospects at the LHC
and the Forward Physics Facility | 35 pages, 15 figures. Accepted for publication in JHEP | null | 10.1007/JHEP03(2023)182 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Hidden sectors are ubiquitous in supergravity theories, in strings and in
branes. Well motivated models such as the Stueckelberg hidden sector model
could provide a candidate for dark matter. In such models, the hidden sector
communicates with the visible sector via the exchange of a dark photon (dark
$Z'$) while dark matter is constituted of Dirac fermions in the hidden sector.
Using data from collider searches and precision measurements of SM processes as
well as the most recent limits from dark matter direct and indirect detection
experiments, we perform a comprehensive scan over a wide range of the $Z'$ mass
and set exclusion bounds on the parameter space from sub-GeV to several TeV. We
then discuss the discovery potential of an $\mathcal{O}$(TeV) scale $Z'$ at
HL-LHC and the ability of future forward detectors to probe very weakly
interacting sub-GeV $Z'$ bosons. Our analysis shows that the parameter space in
which a $Z'$ can decay to hidden sector dark matter is severely constrained
whereas limits become much weaker for a $Z'$ with no dark decays. The analysis
also favors a self-thermalized dark sector which is necessary to satisfy the
dark matter relic density.
| [
{
"created": "Fri, 2 Dec 2022 16:03:55 GMT",
"version": "v1"
},
{
"created": "Sun, 5 Mar 2023 18:57:31 GMT",
"version": "v2"
}
] | 2023-04-12 | [
[
"Aboubrahim",
"Amin",
""
],
[
"Altakach",
"Mohammad Mahdi",
""
],
[
"Klasen",
"Michael",
""
],
[
"Nath",
"Pran",
""
],
[
"Wang",
"Zhu-Yao",
""
]
] | Hidden sectors are ubiquitous in supergravity theories, in strings and in branes. Well motivated models such as the Stueckelberg hidden sector model could provide a candidate for dark matter. In such models, the hidden sector communicates with the visible sector via the exchange of a dark photon (dark $Z'$) while dark matter is constituted of Dirac fermions in the hidden sector. Using data from collider searches and precision measurements of SM processes as well as the most recent limits from dark matter direct and indirect detection experiments, we perform a comprehensive scan over a wide range of the $Z'$ mass and set exclusion bounds on the parameter space from sub-GeV to several TeV. We then discuss the discovery potential of an $\mathcal{O}$(TeV) scale $Z'$ at HL-LHC and the ability of future forward detectors to probe very weakly interacting sub-GeV $Z'$ bosons. Our analysis shows that the parameter space in which a $Z'$ can decay to hidden sector dark matter is severely constrained whereas limits become much weaker for a $Z'$ with no dark decays. The analysis also favors a self-thermalized dark sector which is necessary to satisfy the dark matter relic density. |
0811.4689 | Pietro Faccioli | R. Millo and P. Faccioli | CP-Violation in Low-Energy Photon-Photon Interactions | 8 pages, 2 figures. New results added. Definitive version, published
in Phys. Rev. D | Phys.Rev.D79:065020,2009 | 10.1103/PhysRevD.79.065020 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | CP-violation in the loop-mediated photon-photon interactions would modify the
birefringence of the quantum vacuum. We discuss the implications of this effect
on the PVLAS-Phase II experiment, in which a time-dependent magnetic field is
modulated. We show that the violation of CP would imply the existence of
characteristic Fourier components, in the intensity spectrum of the outgoing
wave. In order to estimate the magnitude of this effect within the Standard
Model, we use chiral perturbation theory to compute the theta-term contribution
to the coefficient of the leading CP-odd vertex, in the low-energy effective
field theory for photon dynamics.
| [
{
"created": "Fri, 28 Nov 2008 11:52:42 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Dec 2008 14:30:45 GMT",
"version": "v2"
},
{
"created": "Tue, 30 Jun 2009 08:24:50 GMT",
"version": "v3"
}
] | 2010-04-30 | [
[
"Millo",
"R.",
""
],
[
"Faccioli",
"P.",
""
]
] | CP-violation in the loop-mediated photon-photon interactions would modify the birefringence of the quantum vacuum. We discuss the implications of this effect on the PVLAS-Phase II experiment, in which a time-dependent magnetic field is modulated. We show that the violation of CP would imply the existence of characteristic Fourier components, in the intensity spectrum of the outgoing wave. In order to estimate the magnitude of this effect within the Standard Model, we use chiral perturbation theory to compute the theta-term contribution to the coefficient of the leading CP-odd vertex, in the low-energy effective field theory for photon dynamics. |
hep-ph/9908484 | Jan Fischer | Jan Fischer (Institute of Physics, Academy of Sciences of the Czech
Republic, Prague) and Ivo Vrkoc (Mathematical Institute, Academy of Sciences
of the Czech Republic, Prague) | Operator product expansion and analyticity | Preprint PRA-HEP 99/04, 20 pages | Int.J.Mod.Phys. A14 (1999) 4819-4840 | 10.1142/S0217751X9900227X | null | hep-ph | null | We discuss the current use of the operator product expansion in QCD
calculations. Treating the OPE as an expansion in inverse powers of an
energy-squared variable (with possible exponential terms added), approximating
the vacuum expectation value of the operator product by several terms and
assuming a bound on the remainder along the euclidean region, we observe how
the bound varies with increasing deflection from the euclidean ray down to the
cut (Minkowski region). We argue that the assumption that the remainder is
constant for all angles in the cut complex plane is not justified. Making
specific assumptions on the properties of the expanded function, we obtain
bounds on the remainder in explicit form and show that they are very sensitive
both to the deflection angle and to the class of functions chosen. The results
obtained are discussed in connetcion with calculations of the coupling constant
\alpha_{s} from the \tau decay.
| [
{
"created": "Fri, 27 Aug 1999 08:54:45 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Fischer",
"Jan",
"",
"Institute of Physics, Academy of Sciences of the Czech\n Republic, Prague"
],
[
"Vrkoc",
"Ivo",
"",
"Mathematical Institute, Academy of Sciences\n of the Czech Republic, Prague"
]
] | We discuss the current use of the operator product expansion in QCD calculations. Treating the OPE as an expansion in inverse powers of an energy-squared variable (with possible exponential terms added), approximating the vacuum expectation value of the operator product by several terms and assuming a bound on the remainder along the euclidean region, we observe how the bound varies with increasing deflection from the euclidean ray down to the cut (Minkowski region). We argue that the assumption that the remainder is constant for all angles in the cut complex plane is not justified. Making specific assumptions on the properties of the expanded function, we obtain bounds on the remainder in explicit form and show that they are very sensitive both to the deflection angle and to the class of functions chosen. The results obtained are discussed in connetcion with calculations of the coupling constant \alpha_{s} from the \tau decay. |
hep-ph/0108218 | Mariana Kirchbach | M. Kirchbach, M. Moshinsky, Yu. F. Smirnov | Baryons in O(4) and Vibron Model | Phys. Rev. D (in press, 2001) | Phys.Rev. D64 (2001) 114005 | 10.1103/PhysRevD.64.114005 | GP-UAZ-01-12 | hep-ph | null | The structure of the reported excitation spectra of the light unflavored
baryons is described in terms of multi-spin valued Lorentz group
representations of the so called Rarita-Schwinger (RS) type (K/2, K/2)* [(1/
2,0)+ (0,1/2)] with K=1,3, and 5. We first motivate legitimacy of such pattern
as fundamental fields as they emerge in the decomposition of triple fermion
constructs into Lorentz representations. We then study the baryon realization
of RS fields as composite systems by means of the quark version of the U(4)
symmetric diatomic rovibron model. In using the U(4)/ O(4)/ O(3)/ O(2)
reduction chain, we are able to reproduce quantum numbers and mass splittings
of the above resonance assemblies. We present the essentials of the four
dimensional angular momentum algebra and construct electromagnetic tensor
operators. The predictive power of the model is illustrated by ratios of
reduced probabilities concerning electric de-excitations of various resonances
to the nucleon.
| [
{
"created": "Mon, 27 Aug 2001 16:39:03 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Kirchbach",
"M.",
""
],
[
"Moshinsky",
"M.",
""
],
[
"Smirnov",
"Yu. F.",
""
]
] | The structure of the reported excitation spectra of the light unflavored baryons is described in terms of multi-spin valued Lorentz group representations of the so called Rarita-Schwinger (RS) type (K/2, K/2)* [(1/ 2,0)+ (0,1/2)] with K=1,3, and 5. We first motivate legitimacy of such pattern as fundamental fields as they emerge in the decomposition of triple fermion constructs into Lorentz representations. We then study the baryon realization of RS fields as composite systems by means of the quark version of the U(4) symmetric diatomic rovibron model. In using the U(4)/ O(4)/ O(3)/ O(2) reduction chain, we are able to reproduce quantum numbers and mass splittings of the above resonance assemblies. We present the essentials of the four dimensional angular momentum algebra and construct electromagnetic tensor operators. The predictive power of the model is illustrated by ratios of reduced probabilities concerning electric de-excitations of various resonances to the nucleon. |
1706.04561 | Cem Salih Un | Yasar Hicyilmaz, Levent Solmaz, Sukru Hanif Tanyildizi and Cem Salih
Un | Least Fine-Tuned U(1) Extended SSM | null | Nuclear Physics B 933, 275 (2018) | 10.1016/j.nuclphysb.2018.05.025 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the Higgs boson mass in a class of the UMSSM models in which the
MSSM gauge group is extended by an additional U(1)' group. Implementing the
universal boundary conditions at the GUT scale we target phenomenologically
interesting regions of UMSSM where the necessary radiative contributions to the
lightest CP-even Higgs boson mass are significantly small and LSP is always the
lightest neutralino. We find that the smallest amount of radiative
contributions is about 50 GeV in UMSSM, this result is much lower than that
obtained in MSSM, which is around 90 GeV. Additionally, we examine the Higgs
boson properties in these models to check if it can behave similar to the SM
Higgs boson under the current experimental constraints. We find that
enforcement of smaller radiative contribution mostly restricts the U(1)'
breaking scale as v_S <~ 10 TeV. Besides, such low contributions demand h_S ~
0.2 - 0.45. Because of the model dependency in realizing these radiative
contributions theta_E_6 < 0 are more favored, if one seeks for the solutions
consistent with the current dark matter constraints. As to the mass spectrum,
we find that stop and stau can be degenerate with the LSP neutralino in the
range from 300 GeV to 700 GeV; however, the dark matter constraints restrict
this scale as m_stop, m_stau >~ 500$ GeV. Such degenerate solutions also
predict stop-neutralino and stau-neutralino coannihilation channels, which are
effective to reduce the relic abundance of neutralino down to the ranges
consistent with the current dark matter observations. Finally, we discuss the
effects of heavy M_Z' in the fine-tuning. Even though the radiative
contributions are significantly low, the required fine-tuning can still be
large. We comment about reinterpretation of the fine-tuning measure in the
UMSSM framework, which can yield efficiently low results for the fine-tuning at
the electroweak scale.
| [
{
"created": "Wed, 14 Jun 2017 16:08:00 GMT",
"version": "v1"
}
] | 2018-06-26 | [
[
"Hicyilmaz",
"Yasar",
""
],
[
"Solmaz",
"Levent",
""
],
[
"Tanyildizi",
"Sukru Hanif",
""
],
[
"Un",
"Cem Salih",
""
]
] | We consider the Higgs boson mass in a class of the UMSSM models in which the MSSM gauge group is extended by an additional U(1)' group. Implementing the universal boundary conditions at the GUT scale we target phenomenologically interesting regions of UMSSM where the necessary radiative contributions to the lightest CP-even Higgs boson mass are significantly small and LSP is always the lightest neutralino. We find that the smallest amount of radiative contributions is about 50 GeV in UMSSM, this result is much lower than that obtained in MSSM, which is around 90 GeV. Additionally, we examine the Higgs boson properties in these models to check if it can behave similar to the SM Higgs boson under the current experimental constraints. We find that enforcement of smaller radiative contribution mostly restricts the U(1)' breaking scale as v_S <~ 10 TeV. Besides, such low contributions demand h_S ~ 0.2 - 0.45. Because of the model dependency in realizing these radiative contributions theta_E_6 < 0 are more favored, if one seeks for the solutions consistent with the current dark matter constraints. As to the mass spectrum, we find that stop and stau can be degenerate with the LSP neutralino in the range from 300 GeV to 700 GeV; however, the dark matter constraints restrict this scale as m_stop, m_stau >~ 500$ GeV. Such degenerate solutions also predict stop-neutralino and stau-neutralino coannihilation channels, which are effective to reduce the relic abundance of neutralino down to the ranges consistent with the current dark matter observations. Finally, we discuss the effects of heavy M_Z' in the fine-tuning. Even though the radiative contributions are significantly low, the required fine-tuning can still be large. We comment about reinterpretation of the fine-tuning measure in the UMSSM framework, which can yield efficiently low results for the fine-tuning at the electroweak scale. |
hep-ph/0308259 | Maozhi Yang | Dong-Sheng Du, Jing-Wu Li, Mao-Zhi Yang | Form Factors and semileptonic decay of $D_s^+\to \phi \bar{\ell}\nu$
from QCD sum rule | version to appear in Eur.Phys.J.C | Eur.Phys.J. C37 (2004) 173-184 | 10.1140/epjc/s2004-01979-9 | BIHEP-TH-2003-30 | hep-ph | null | We calculate $D_s^+\to \phi$ transition form factors $V$, $A_0$, $A_1$ and
$A_2$, and study semileptonic decay of $D_s^+\to \phi \bar{\ell}\nu$ based on
QCD sum rule method. We compare our results of the ratios of $V(0)/A_1(0)$,
$A_2(0)/A_1(0)$, $\Gamma_L/\Gamma_T$, and the total decay branching ratio of
$D_s^+\to \phi \bar{\ell}\nu$ with experimental data, and find that they are
consistent.
| [
{
"created": "Tue, 26 Aug 2003 11:50:12 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Mar 2004 09:30:49 GMT",
"version": "v2"
},
{
"created": "Wed, 1 Sep 2004 03:43:10 GMT",
"version": "v3"
}
] | 2016-04-26 | [
[
"Du",
"Dong-Sheng",
""
],
[
"Li",
"Jing-Wu",
""
],
[
"Yang",
"Mao-Zhi",
""
]
] | We calculate $D_s^+\to \phi$ transition form factors $V$, $A_0$, $A_1$ and $A_2$, and study semileptonic decay of $D_s^+\to \phi \bar{\ell}\nu$ based on QCD sum rule method. We compare our results of the ratios of $V(0)/A_1(0)$, $A_2(0)/A_1(0)$, $\Gamma_L/\Gamma_T$, and the total decay branching ratio of $D_s^+\to \phi \bar{\ell}\nu$ with experimental data, and find that they are consistent. |
1106.5035 | Alfonso Rosado | J. Hern\'andez-S\'anchez, L. L\'opez-Lozano, R. Noriega-Papaqui, and
A. Rosado | Couplings of quarks in the Partially Aligned 2HDM with a four-zero
texture Yukawa matrix | 11 pages, 1 figure | Physical Review D 85, 071301(R) (2012) | 10.1103/PhysRevD.85.071301 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Two Higgs Doublets Model (2HDM) has provided a very useful way to
describe a minimal extension of the scalar sector of the Standard Model. In
this work, it is shown a scheme that we call Partial Aligned Two Higgs Doublet
Model (PA-2HDM) which allows a description of the distinct versions of the 2HDM
in a simple way, including those with flavor symmetries. In addition, it is
shown a method to diagonalize Yukawa matrices of four-zero texture coming from
the 2HDM-III. We provide some phenomenological applications in order to show
the model's predictive power.
| [
{
"created": "Fri, 24 Jun 2011 18:50:30 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Mar 2012 05:03:26 GMT",
"version": "v2"
}
] | 2012-04-25 | [
[
"Hernández-Sánchez",
"J.",
""
],
[
"López-Lozano",
"L.",
""
],
[
"Noriega-Papaqui",
"R.",
""
],
[
"Rosado",
"A.",
""
]
] | The Two Higgs Doublets Model (2HDM) has provided a very useful way to describe a minimal extension of the scalar sector of the Standard Model. In this work, it is shown a scheme that we call Partial Aligned Two Higgs Doublet Model (PA-2HDM) which allows a description of the distinct versions of the 2HDM in a simple way, including those with flavor symmetries. In addition, it is shown a method to diagonalize Yukawa matrices of four-zero texture coming from the 2HDM-III. We provide some phenomenological applications in order to show the model's predictive power. |
hep-ph/0703233 | Zhe Xu | Zhe Xu and Carsten Greiner | Transport rates and momentum isotropization of gluon matter in
ultrarelativistic heavy-ion collisions | 44 pages, 16 figures, text updated, references added, 1 new figure
added; final version published in PRC | Phys.Rev.C76:024911,2007 | 10.1103/PhysRevC.76.024911 | null | hep-ph nucl-th | null | To describe momentum isotropization of gluon matter produced in
ultrarelativistic heavy-ion collisions, the transport rate of gluon drift and
the transport collision rates of elastic ($gg \leftrightarrow gg$) as well as
inelastic ($gg \leftrightarrow ggg$) perturbative quantum chromodynamics-
(pQCD) scattering processes are introduced and calculated within the kinetic
parton cascade Boltzmann approach of multiparton scatterings (BAMPS), which
simulates the space-time evolution of partons. We define isotropization as the
development of an anisotropic system as it reaches isotropy. The inverse of the
introduced total transport rate gives the correct time scale of the momentum
isotropization. The contributions of the various scattering processes to the
momentum isotropization can be separated into the transport collision rates. In
contrast to the transport cross section, the transport collision rate has an
indirect but correctly implemented relationship with the collision-angle
distribution. Based on the calculated transport collision rates from BAMPS for
central Au+Au collisions at Relativistic Heavy Ion Collider energies, we show
that pQCD $gg \leftrightarrow ggg$ bremsstrahlung processes isotropize the
momentum five times more efficiently than elastic scatterings. The large
efficiency of the bremsstrahlung stems mainly from its large momentum
deflection. Due to kinematics, $2\to N$ $(N>2)$ production processes allow more
particles to become isotropic in momentum space and thus kinetically
equilibrate more quickly than their back reactions or elastic scatterings. We
also show that the relaxation time in the relaxation time approximation, which
is often used, is strongly momentum dependent and thus cannot serve as a global
quantity that describes kinetic equilibration.
| [
{
"created": "Wed, 21 Mar 2007 20:28:40 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Aug 2007 11:48:34 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Xu",
"Zhe",
""
],
[
"Greiner",
"Carsten",
""
]
] | To describe momentum isotropization of gluon matter produced in ultrarelativistic heavy-ion collisions, the transport rate of gluon drift and the transport collision rates of elastic ($gg \leftrightarrow gg$) as well as inelastic ($gg \leftrightarrow ggg$) perturbative quantum chromodynamics- (pQCD) scattering processes are introduced and calculated within the kinetic parton cascade Boltzmann approach of multiparton scatterings (BAMPS), which simulates the space-time evolution of partons. We define isotropization as the development of an anisotropic system as it reaches isotropy. The inverse of the introduced total transport rate gives the correct time scale of the momentum isotropization. The contributions of the various scattering processes to the momentum isotropization can be separated into the transport collision rates. In contrast to the transport cross section, the transport collision rate has an indirect but correctly implemented relationship with the collision-angle distribution. Based on the calculated transport collision rates from BAMPS for central Au+Au collisions at Relativistic Heavy Ion Collider energies, we show that pQCD $gg \leftrightarrow ggg$ bremsstrahlung processes isotropize the momentum five times more efficiently than elastic scatterings. The large efficiency of the bremsstrahlung stems mainly from its large momentum deflection. Due to kinematics, $2\to N$ $(N>2)$ production processes allow more particles to become isotropic in momentum space and thus kinetically equilibrate more quickly than their back reactions or elastic scatterings. We also show that the relaxation time in the relaxation time approximation, which is often used, is strongly momentum dependent and thus cannot serve as a global quantity that describes kinetic equilibration. |
2407.16409 | N. Manan Shah | Rameshri V. Patel and Manan N. Shah | Cascade ($\Xi^0$) Baryon Spectroscopy in the Relativistic Framework of
Independent Quark Model | 10 Pages, 4 Figures, 8 Tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The spectroscopy of $\Xi^0$ is performed within the relativistic framework of
independent quark model. The equal mixture of scalar and vector components in
the potential having Martin-like form is considered for the confinement. With
the suitable potential parameters for $\Xi^0$, mass spectra for high radial and
orbital excitation is calculated. The experimentally observed values of ground
state magnetic moment, branching ratios and asymmetry parameters for radiative
weak decays, $\Xi^{0}\rightarrow\Lambda^{0} + \gamma^{0}$ \&
$\Xi^{0}\rightarrow\Sigma^{0} + \gamma^{0}$ are obtained to validate the model.
The spin parity of experimentally known resonances like $\Xi(1530)$,
$\Xi(1820)$, \& $\Xi(2030)$ are confirmed through the Regge trajectories in
$(J,M^2)$ plane. The spin pa+rity of $\Xi(1950)$, $\Xi(2130)$, \& $\Xi(2250)$
are predicted using those Regge trajectories. The radiative decay width and
magnetic moment of first resonance is also predicted.
| [
{
"created": "Tue, 23 Jul 2024 11:56:11 GMT",
"version": "v1"
}
] | 2024-07-24 | [
[
"Patel",
"Rameshri V.",
""
],
[
"Shah",
"Manan N.",
""
]
] | The spectroscopy of $\Xi^0$ is performed within the relativistic framework of independent quark model. The equal mixture of scalar and vector components in the potential having Martin-like form is considered for the confinement. With the suitable potential parameters for $\Xi^0$, mass spectra for high radial and orbital excitation is calculated. The experimentally observed values of ground state magnetic moment, branching ratios and asymmetry parameters for radiative weak decays, $\Xi^{0}\rightarrow\Lambda^{0} + \gamma^{0}$ \& $\Xi^{0}\rightarrow\Sigma^{0} + \gamma^{0}$ are obtained to validate the model. The spin parity of experimentally known resonances like $\Xi(1530)$, $\Xi(1820)$, \& $\Xi(2030)$ are confirmed through the Regge trajectories in $(J,M^2)$ plane. The spin pa+rity of $\Xi(1950)$, $\Xi(2130)$, \& $\Xi(2250)$ are predicted using those Regge trajectories. The radiative decay width and magnetic moment of first resonance is also predicted. |
hep-ph/0305145 | masayuki Uehara | Masayuki Uehara | Final State Interactions in Kaon Decays Revisited | 6 pages and 2 eps figures, LaTeX2 | Prog.Theor.Phys.110:769-775,2003 | 10.1143/PTP.110.769 | null | hep-ph | null | We examine effects of final state interactions (FSI) in kaon decays using a
new scheme without the Omnes function, and show that while Delta I=1/2 rule is
impossible to be explained in terms of FSI alone, $\epsilon'/\epsilon\sim
16.5\times 10^{-4}$ is obtained through FSI, if the calculation is concerned
only with the CP-violating parts. The pi-pi contribution to the m_L-m_S mass
difference is shown to be about 0.14, if the sizes of the CP conserving
amplitudes A_0 and A_2 are correctly given.
| [
{
"created": "Wed, 14 May 2003 02:14:50 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Uehara",
"Masayuki",
""
]
] | We examine effects of final state interactions (FSI) in kaon decays using a new scheme without the Omnes function, and show that while Delta I=1/2 rule is impossible to be explained in terms of FSI alone, $\epsilon'/\epsilon\sim 16.5\times 10^{-4}$ is obtained through FSI, if the calculation is concerned only with the CP-violating parts. The pi-pi contribution to the m_L-m_S mass difference is shown to be about 0.14, if the sizes of the CP conserving amplitudes A_0 and A_2 are correctly given. |
hep-ph/0605086 | Luis Anchordoqui | Luis A. Anchordoqui, Amanda M. Cooper-Sarkar, Dan Hooper, and Subir
Sarkar | Probing low-x QCD with cosmic neutrinos at the Pierre Auger Observatory | Accepted for publication in Phys Rev D; Details of the NLO
neutrino-nucleon cross-section calculation available at:
http://www-pnp.physics.ox.ac.uk/~cooper/neutrino.html | Phys.Rev.D74:043008,2006 | 10.1103/PhysRevD.74.043008 | FERMILAB-PUB-06-095-A | hep-ph astro-ph hep-th | null | The sources of the observed ultra-high energy cosmic rays must also generate
ultra-high energy neutrinos. Deep inelastic scattering of these neutrinos with
nucleons on Earth probe center-of-mass energies $\sqrt{s} \sim 100$ TeV, well
beyond those attainable at terrestrial colliders. By comparing the rates for
two classes of observable events, any departure from the benchmark (unscreened
perturbative QCD) neutrino-nucleon cross-section can be constrained. Using the
projected sensitivity of the Pierre Auger Observatory to quasi-horizontal
showers and Earth-skimming tau neutrinos, we show that a `Super-Auger' detector
can thus provide an unique probe of strong interaction dynamics.
| [
{
"created": "Tue, 9 May 2006 13:26:14 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Aug 2006 12:27:38 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Anchordoqui",
"Luis A.",
""
],
[
"Cooper-Sarkar",
"Amanda M.",
""
],
[
"Hooper",
"Dan",
""
],
[
"Sarkar",
"Subir",
""
]
] | The sources of the observed ultra-high energy cosmic rays must also generate ultra-high energy neutrinos. Deep inelastic scattering of these neutrinos with nucleons on Earth probe center-of-mass energies $\sqrt{s} \sim 100$ TeV, well beyond those attainable at terrestrial colliders. By comparing the rates for two classes of observable events, any departure from the benchmark (unscreened perturbative QCD) neutrino-nucleon cross-section can be constrained. Using the projected sensitivity of the Pierre Auger Observatory to quasi-horizontal showers and Earth-skimming tau neutrinos, we show that a `Super-Auger' detector can thus provide an unique probe of strong interaction dynamics. |
2111.05852 | Steven Harris | P. S. Bhupal Dev, Jean-Fran\c{c}ois Fortin, Steven P. Harris, Kuver
Sinha, Yongchao Zhang | Light scalars in neutron star mergers | 44 pages, 10 figures v2: Matches version to be published in JCAP.
Added a discussion of the Boltzmann suppression of the emissivity (fig 5)
that occurs for scalar particles with m_S >> T. Added some material on the
role of pions | null | 10.1088/1475-7516/2022/01/006 | INT-PUB-21-024 | hep-ph astro-ph.HE nucl-th | http://creativecommons.org/licenses/by/4.0/ | Due to their unique set of multimessenger signals, neutron star mergers have
emerged as a novel environment for studies of new physics beyond the Standard
Model (SM). As a case study, we consider the simplest extension of the SM
scalar sector involving a light CP-even scalar singlet $S$ mixing with the SM
Higgs boson. These $S$ particles can be produced abundantly in neutron star
mergers via the nucleon bremsstrahlung process. We show that the $S$ particles
may either be trapped in or stream freely out of the merger remnant, depending
on the $S$ mass, its mixing with the SM Higgs boson, and the temperature and
baryon density in the merger. In the free-streaming region, the scalar $S$ will
provide an extra channel to cool down the merger remnant, with cooling
timescales as small as ${\cal O}$(ms). On the other hand, in the trapped
region, the Bose gas of $S$ particles could contribute a larger thermal
conductivity than the trapped neutrinos in some parts of the parameter space,
thus leading to faster thermal equilibration than expected. Therefore, future
observations of the early postmerger phase of a neutron star merger could
effectively probe a unique range of the $S$ parameter space, largely
complementary to the existing and future laboratory and supernova limits. In
view of these results, we hope the merger simulation community will be
motivated to implement the effects of light CP-even scalars into their
simulations in both the free-streaming and trapped regimes.
| [
{
"created": "Wed, 10 Nov 2021 18:59:59 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Dec 2021 17:58:14 GMT",
"version": "v2"
}
] | 2022-01-12 | [
[
"Dev",
"P. S. Bhupal",
""
],
[
"Fortin",
"Jean-François",
""
],
[
"Harris",
"Steven P.",
""
],
[
"Sinha",
"Kuver",
""
],
[
"Zhang",
"Yongchao",
""
]
] | Due to their unique set of multimessenger signals, neutron star mergers have emerged as a novel environment for studies of new physics beyond the Standard Model (SM). As a case study, we consider the simplest extension of the SM scalar sector involving a light CP-even scalar singlet $S$ mixing with the SM Higgs boson. These $S$ particles can be produced abundantly in neutron star mergers via the nucleon bremsstrahlung process. We show that the $S$ particles may either be trapped in or stream freely out of the merger remnant, depending on the $S$ mass, its mixing with the SM Higgs boson, and the temperature and baryon density in the merger. In the free-streaming region, the scalar $S$ will provide an extra channel to cool down the merger remnant, with cooling timescales as small as ${\cal O}$(ms). On the other hand, in the trapped region, the Bose gas of $S$ particles could contribute a larger thermal conductivity than the trapped neutrinos in some parts of the parameter space, thus leading to faster thermal equilibration than expected. Therefore, future observations of the early postmerger phase of a neutron star merger could effectively probe a unique range of the $S$ parameter space, largely complementary to the existing and future laboratory and supernova limits. In view of these results, we hope the merger simulation community will be motivated to implement the effects of light CP-even scalars into their simulations in both the free-streaming and trapped regimes. |
1810.01889 | Abhishek Banerjee | Abhishek Banerjee, Hyungjin Kim, and Gilad Perez | Coherent relaxion dark matter | 8 pages, 1 figure; v2 matches version accepted by PRD, previously
ignored effect included, available parameter space shifted, discussion
extended | Phys. Rev. D 100, 115026 (2019) | 10.1103/PhysRevD.100.115026 | null | hep-ph physics.atom-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that relaxion, that addresses the hierarchy problem, can account for
the observed dark matter (DM) relic density. The setup is similar to the case
of axion DM models topped with a dynamical misalignment mechanism. After the
reheating, when the temperature is well above the electroweak scale, the
backreaction potential disappears and the relaxion is displaced from its
vacuum. When the "wiggles" reappear the relaxion coherently oscillates around
its minimum as in the case of vanilla axion DM models. We identify the
parameter space such that the relaxion is retrapped leading to the standard
cosmology. When the relaxion is lighter than $10^{-7}\,$eV, Hubble friction
during radiation-domination is sufficiently strong for retrapping, and even
minimal models are found to be viable. It also leads to a new constraint on
relaxion models, as a certain region of their parameter space could lead to
overabundant relaxion DM. Alternatively, even a larger parameter space exists
when additional friction is obtained by particle production from additional
coupling to an additional dark photon field. The phenomenology of this class of
models is quite unique, as it implies that we are surrounded by a
time-dependent axion-like field that due to relaxion-Higgs mixing implies
time-dependent Higgs vacuum-expectation-value that lead to time-variation of
all coupling constants of nature.
| [
{
"created": "Wed, 3 Oct 2018 18:00:06 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Nov 2019 09:00:43 GMT",
"version": "v2"
}
] | 2020-01-14 | [
[
"Banerjee",
"Abhishek",
""
],
[
"Kim",
"Hyungjin",
""
],
[
"Perez",
"Gilad",
""
]
] | We show that relaxion, that addresses the hierarchy problem, can account for the observed dark matter (DM) relic density. The setup is similar to the case of axion DM models topped with a dynamical misalignment mechanism. After the reheating, when the temperature is well above the electroweak scale, the backreaction potential disappears and the relaxion is displaced from its vacuum. When the "wiggles" reappear the relaxion coherently oscillates around its minimum as in the case of vanilla axion DM models. We identify the parameter space such that the relaxion is retrapped leading to the standard cosmology. When the relaxion is lighter than $10^{-7}\,$eV, Hubble friction during radiation-domination is sufficiently strong for retrapping, and even minimal models are found to be viable. It also leads to a new constraint on relaxion models, as a certain region of their parameter space could lead to overabundant relaxion DM. Alternatively, even a larger parameter space exists when additional friction is obtained by particle production from additional coupling to an additional dark photon field. The phenomenology of this class of models is quite unique, as it implies that we are surrounded by a time-dependent axion-like field that due to relaxion-Higgs mixing implies time-dependent Higgs vacuum-expectation-value that lead to time-variation of all coupling constants of nature. |
1812.04644 | Jonas Wittbrodt | Wolfgang G. Hollik, Georg Weiglein, Jonas Wittbrodt | Impact of Vacuum Stability Constraints on the Phenomenology of
Supersymmetric Models | 36 pages, 13 figures, updated Delta_tau corrections and FeynHiggs
version, added references, conclusions unchanged | null | 10.1007/JHEP03(2019)109 | DESY 18-148, TTP 18-036 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a fast and efficient method for studying vacuum stability
constraints in multi-scalar theories beyond the Standard Model. This method is
designed for a reliable use in large scale parameter scans. The minimization of
the scalar potential is done with the well-known polynomial homotopy
continuation, and the decay rate of a false vacuum in a multi-scalar theory is
estimated by an exact solution of the bounce action in the one-field case. We
compare to more precise calculations of the tunnelling path at the tree- and
one-loop level and find good agreement for the resulting constraints on the
parameter space. Numerical stability, runtime and reliability are significantly
improved compared to approaches existing in the literature. This procedure is
applied to several phenomenologically interesting benchmark scenarios defined
in the Minimal Supersymmetric Standard Model. We utilize our efficient approach
to study the impact of simultaneously varying multiple fields and illustrate
the importance of correctly identifying the most dangerous minimum among the
minima that are deeper than the electroweak vacuum.
| [
{
"created": "Tue, 11 Dec 2018 19:01:30 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Jan 2019 11:21:45 GMT",
"version": "v2"
}
] | 2019-05-01 | [
[
"Hollik",
"Wolfgang G.",
""
],
[
"Weiglein",
"Georg",
""
],
[
"Wittbrodt",
"Jonas",
""
]
] | We present a fast and efficient method for studying vacuum stability constraints in multi-scalar theories beyond the Standard Model. This method is designed for a reliable use in large scale parameter scans. The minimization of the scalar potential is done with the well-known polynomial homotopy continuation, and the decay rate of a false vacuum in a multi-scalar theory is estimated by an exact solution of the bounce action in the one-field case. We compare to more precise calculations of the tunnelling path at the tree- and one-loop level and find good agreement for the resulting constraints on the parameter space. Numerical stability, runtime and reliability are significantly improved compared to approaches existing in the literature. This procedure is applied to several phenomenologically interesting benchmark scenarios defined in the Minimal Supersymmetric Standard Model. We utilize our efficient approach to study the impact of simultaneously varying multiple fields and illustrate the importance of correctly identifying the most dangerous minimum among the minima that are deeper than the electroweak vacuum. |
hep-ph/9608488 | Andrei Semenov | A. V. Semenov (INP MSU, Moscow, Russia) | LanHEP - a package for automatic generation of Feynman rules in gauge
models | 28 pages, LaTeX, no pictures. Text layout corrected | null | null | INP MSU 96-24/431 | hep-ph | null | We consider the general problem of derivation of the Feynman rules for the
matrix elements in momentum representation from the given Lagrangian in
coordinate space invariant under the transformation of some gauge group. LanHEP
package presented in this paper allows to define in a convenient way the gauge
model Lagrangian in canonical form and then to generate automatically the
Feynman rules that can be used in the following calculation of the physical
processes by means of CompHEP package. The detailed description of LanHEP
commands is given and several examples of LanHEP applications (QED, QCD,
Standard Model in the t'Hooft-Feynman gauge) are presented.
| [
{
"created": "Thu, 29 Aug 1996 17:16:52 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Aug 1996 13:44:29 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Semenov",
"A. V.",
"",
"INP MSU, Moscow, Russia"
]
] | We consider the general problem of derivation of the Feynman rules for the matrix elements in momentum representation from the given Lagrangian in coordinate space invariant under the transformation of some gauge group. LanHEP package presented in this paper allows to define in a convenient way the gauge model Lagrangian in canonical form and then to generate automatically the Feynman rules that can be used in the following calculation of the physical processes by means of CompHEP package. The detailed description of LanHEP commands is given and several examples of LanHEP applications (QED, QCD, Standard Model in the t'Hooft-Feynman gauge) are presented. |
hep-ph/9408225 | Tony Gherghetta | Tony Gherghetta | Regularization in the Gauged Nambu--Jona-Lasinio Model | 12 pages, LaTeX with 3 uuencoded tar-compressed figures submitted
separately, requires epsf.tex, EFI-93-67. Complete postscript file also
available by anonymous ftp at rainbow.uchicago.edu:
/pt-preprints/efi-93-67.ps.Z | Phys.Rev. D50 (1994) 5985-5992 | 10.1103/PhysRevD.50.5985 | null | hep-ph | null | Various prescriptions employed for regulating gauged Nambu--Jona-Lasinio type
models such as the top-quark condensate model are discussed. The use of
dimensional regularization maintains gauge invariance but destroys the
quadratic divergence in the gap equation. If instead a simple ultraviolet
momentum cutoff is used to regulate loop integrals, then gauge invariance is
destroyed by a quadratically divergent term as well as by ambiguities
associated with arbitrary routing of loop momenta. Finally it is shown that one
can use dispersion relations to regulate the top-quark condensate model. This
prescription maintains gauge invariance and does not depend on arbitrary shifts
in loop momenta.
| [
{
"created": "Wed, 3 Aug 1994 18:17:55 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Gherghetta",
"Tony",
""
]
] | Various prescriptions employed for regulating gauged Nambu--Jona-Lasinio type models such as the top-quark condensate model are discussed. The use of dimensional regularization maintains gauge invariance but destroys the quadratic divergence in the gap equation. If instead a simple ultraviolet momentum cutoff is used to regulate loop integrals, then gauge invariance is destroyed by a quadratically divergent term as well as by ambiguities associated with arbitrary routing of loop momenta. Finally it is shown that one can use dispersion relations to regulate the top-quark condensate model. This prescription maintains gauge invariance and does not depend on arbitrary shifts in loop momenta. |
hep-ph/0502086 | Jeff Forshaw | J.R. Forshaw, A. Kyrieleis, M.H. Seymour | Gaps between Jets in the High Energy Limit | 29 pages, 9 figures, minor corrections to text and improved figures | JHEP 0506:034,2005 | 10.1088/1126-6708/2005/06/034 | null | hep-ph | null | We use perturbative QCD to calculate the parton level cross section for the
production of two jets that are far apart in rapidity, subject to a limitation
on the total transverse momentum Q0 in the interjet region. We specifically
address the question of how to combine the approach which sums all leading
logarithms in Q/Q0 (where Q is the jet transverse momentum) with the BFKL
approach, in which leading logarithms of the scattering energy are summed. This
paper constitutes progress towards the simultaneous summation of all important
logarithms. Using an "all orders" matching, we are able to obtain results for
the cross section which correctly reproduce the two approaches in the
appropriate limits.
| [
{
"created": "Wed, 9 Feb 2005 14:37:22 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Jun 2005 17:31:16 GMT",
"version": "v2"
}
] | 2010-03-12 | [
[
"Forshaw",
"J. R.",
""
],
[
"Kyrieleis",
"A.",
""
],
[
"Seymour",
"M. H.",
""
]
] | We use perturbative QCD to calculate the parton level cross section for the production of two jets that are far apart in rapidity, subject to a limitation on the total transverse momentum Q0 in the interjet region. We specifically address the question of how to combine the approach which sums all leading logarithms in Q/Q0 (where Q is the jet transverse momentum) with the BFKL approach, in which leading logarithms of the scattering energy are summed. This paper constitutes progress towards the simultaneous summation of all important logarithms. Using an "all orders" matching, we are able to obtain results for the cross section which correctly reproduce the two approaches in the appropriate limits. |
1906.03903 | Emilio Mendoza | E. Mendoza, D. Cano-Ott, P. Romojaro, V. Alcayne, P. Garc\'ia Abia, V.
Pesudo, L. Romero and R. Santorelli | Neutron production induced by $\alpha$-decay with Geant4 | null | null | 10.1016/j.nima.2020.163659 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Neutron production induced by ($\alpha$,n) reactions is important in various
scenarios. One of the most relevant ones is related to underground dark matter
experiments, where the neutrons produced by the $\alpha$-decay from radioactive
contaminants in the detector materials can generate an irreducible background,
limiting the sensitivity of the experiment. A precise estimate of the
background due to these neutrons is crucial for the experiments currently
taking data and for the design of the next generation detectors. In this work,
we prove that Geant4 can be used to calculate neutron yields and energy spectra
induced by $\alpha$-decay. These neutrons are produced according to the
information compiled in data libraries originally written in the ENDF-6 format.
In this article we also review the different databases available, showing the
differences and similarities among them. Finally, we compare several Geant4
neutron production yields and spectra with experimental data and other codes.
| [
{
"created": "Mon, 10 Jun 2019 11:15:49 GMT",
"version": "v1"
}
] | 2020-02-21 | [
[
"Mendoza",
"E.",
""
],
[
"Cano-Ott",
"D.",
""
],
[
"Romojaro",
"P.",
""
],
[
"Alcayne",
"V.",
""
],
[
"Abia",
"P. García",
""
],
[
"Pesudo",
"V.",
""
],
[
"Romero",
"L.",
""
],
[
"Santorelli",
"... | Neutron production induced by ($\alpha$,n) reactions is important in various scenarios. One of the most relevant ones is related to underground dark matter experiments, where the neutrons produced by the $\alpha$-decay from radioactive contaminants in the detector materials can generate an irreducible background, limiting the sensitivity of the experiment. A precise estimate of the background due to these neutrons is crucial for the experiments currently taking data and for the design of the next generation detectors. In this work, we prove that Geant4 can be used to calculate neutron yields and energy spectra induced by $\alpha$-decay. These neutrons are produced according to the information compiled in data libraries originally written in the ENDF-6 format. In this article we also review the different databases available, showing the differences and similarities among them. Finally, we compare several Geant4 neutron production yields and spectra with experimental data and other codes. |
2211.12546 | Mohamed Ouchemhou | R.Benbrik, M. Boukidi, M. Ouchemhou, L. Rahili, and O. Tibssirte | Higgs-like particle decays into $\gamma Z$ and $\gamma\gamma$ :
Fingerprints of some non-supersymmetric models | 34 pages, 19 figures | null | 10.1016/j.nuclphysb.2023.116154 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently, ATLAS and CMS experiments at the LHC put on light the relevant
results in the measurement precision of the Higgs and BSM. In such a report,
where the resonance direct search was made in the $\gamma Z$ channel, a mass
adjustment distribution for the reconstructed $Z$ boson and photon was
established. Thus, simultaneously with the signal-from-background separation,
the number of events has been perfectly described, and an excess signal
approximately twice that expected by the Standard Model (SM) has been noticed,
which is equivalent to a significance of 2.2 standard deviations. In this
study, we examine how any possible new physics models can explain this excess,
such as the CP-conserving Two-Higgs doublet model (2HDMs), the Inert doublet
model (IDM), and the Higgs triplet model (HTM). While considering the available
theoretical and most recent experimental constraints, the phenomenological
implications of existing extensions beyond the SM are discussed, and prospects
for precision studies of these processes are described. We have found that the
excess could be explained in the BSM framework studied, depending on the
charged and double-charged Higgs boson masses.
| [
{
"created": "Tue, 22 Nov 2022 19:41:46 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Jun 2023 23:21:40 GMT",
"version": "v2"
}
] | 2023-06-29 | [
[
"Benbrik",
"R.",
""
],
[
"Boukidi",
"M.",
""
],
[
"Ouchemhou",
"M.",
""
],
[
"Rahili",
"L.",
""
],
[
"Tibssirte",
"O.",
""
]
] | Recently, ATLAS and CMS experiments at the LHC put on light the relevant results in the measurement precision of the Higgs and BSM. In such a report, where the resonance direct search was made in the $\gamma Z$ channel, a mass adjustment distribution for the reconstructed $Z$ boson and photon was established. Thus, simultaneously with the signal-from-background separation, the number of events has been perfectly described, and an excess signal approximately twice that expected by the Standard Model (SM) has been noticed, which is equivalent to a significance of 2.2 standard deviations. In this study, we examine how any possible new physics models can explain this excess, such as the CP-conserving Two-Higgs doublet model (2HDMs), the Inert doublet model (IDM), and the Higgs triplet model (HTM). While considering the available theoretical and most recent experimental constraints, the phenomenological implications of existing extensions beyond the SM are discussed, and prospects for precision studies of these processes are described. We have found that the excess could be explained in the BSM framework studied, depending on the charged and double-charged Higgs boson masses. |
hep-ph/9807448 | Michael Rueter | Michael Rueter (Tel-Aviv University) | Energy and Q^2 dependence of elastic vectormeson production and the
proton structure function F_2 | 28 pages, LaTex2e, uses graphicx package for eps-figures | Eur.Phys.J.C7:233-249,1999 | 10.1007/s100529801002 | TAUP-2507-98 | hep-ph hep-ex | null | In the framework of the Model of the Stochastic Vacuum elastic hadron-hadron
scattering, photo- and electroproduction of vectormesons and also F_2(Q^2) can
be well described at center of mass energy approximately 20 GeV. The scattering
amplitude is derived by smearing the color dipole-dipole scattering, which is
calculated nonperturbatively in the Model of the Stochastic Vacuum, with
appropriate wavefunctions. For the considered processes the dipoles have
extensions in the range of hadron sizes. We now extend this idea to small
dipoles and high energies. The energy dependence is modeled in a
phenomenological way: we assume that there a two pomerons, the soft- and the
hard-pomeron, each being a simple pole in the complex angular plane. We couple
dipoles of hadronic size to the soft-pomeron and small dipoles to the
hard-pomeron. For small dipoles we take the perturbative gluon exchange into
account. By that way we obtain an energy dependent dipole-dipole scattering
amplitude which can be used for all the processes with the same parameters. We
show that this approach can describe in addition to all the low energy results
(20 GeV) also the HERA data for the considered processes in a large energy and
Q^2 range. Especially the right transition from the soft to the hard behavior
is observed.
| [
{
"created": "Tue, 21 Jul 1998 16:14:54 GMT",
"version": "v1"
}
] | 2011-09-13 | [
[
"Rueter",
"Michael",
"",
"Tel-Aviv University"
]
] | In the framework of the Model of the Stochastic Vacuum elastic hadron-hadron scattering, photo- and electroproduction of vectormesons and also F_2(Q^2) can be well described at center of mass energy approximately 20 GeV. The scattering amplitude is derived by smearing the color dipole-dipole scattering, which is calculated nonperturbatively in the Model of the Stochastic Vacuum, with appropriate wavefunctions. For the considered processes the dipoles have extensions in the range of hadron sizes. We now extend this idea to small dipoles and high energies. The energy dependence is modeled in a phenomenological way: we assume that there a two pomerons, the soft- and the hard-pomeron, each being a simple pole in the complex angular plane. We couple dipoles of hadronic size to the soft-pomeron and small dipoles to the hard-pomeron. For small dipoles we take the perturbative gluon exchange into account. By that way we obtain an energy dependent dipole-dipole scattering amplitude which can be used for all the processes with the same parameters. We show that this approach can describe in addition to all the low energy results (20 GeV) also the HERA data for the considered processes in a large energy and Q^2 range. Especially the right transition from the soft to the hard behavior is observed. |
2105.04434 | Yiyu Zhou | Y. Zhou, C. Cocuzza, F. Delcarro, W. Melnitchouk, A. Metz, N. Sato | Revisiting quark and gluon polarization in the proton at the EIC | 23 pages, 7 figures | Phys. Rev. D 104, 034028 (2021) | 10.1103/PhysRevD.104.034028 | JLAB-THY-21-3368 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a comprehensive impact study of future Electron-Ion Collider (EIC)
data for parity-conserving and parity-violating polarization asymmetries on
quark and gluon helicity distributions in the proton. The study, which is based
on the JAM Monte Carlo global QCD analysis framework, explores the role of the
extrapolation uncertainty and SU(3) flavor symmetry constraints in the
simulated double-spin asymmetry, $A_{LL}$, at small parton momentum fractions
$x$ and its effect on the extracted parton polarizations. We find that
different assumptions about $A_{LL}$ extrapolations and SU(3) symmetry can have
significant consequences for the integrated quark and gluon polarizations, for
polarized proton, deuteron and $^3$He beams. For the parity-violating
asymmetry, $A_{UL}$, we study the potential impact on the polarized strange
quark distribution with different extrapolations of $A_{UL}$, finding the
constraining power to be ultimately limited by the EIC machine luminosity.
| [
{
"created": "Mon, 10 May 2021 14:46:47 GMT",
"version": "v1"
}
] | 2021-09-01 | [
[
"Zhou",
"Y.",
""
],
[
"Cocuzza",
"C.",
""
],
[
"Delcarro",
"F.",
""
],
[
"Melnitchouk",
"W.",
""
],
[
"Metz",
"A.",
""
],
[
"Sato",
"N.",
""
]
] | We present a comprehensive impact study of future Electron-Ion Collider (EIC) data for parity-conserving and parity-violating polarization asymmetries on quark and gluon helicity distributions in the proton. The study, which is based on the JAM Monte Carlo global QCD analysis framework, explores the role of the extrapolation uncertainty and SU(3) flavor symmetry constraints in the simulated double-spin asymmetry, $A_{LL}$, at small parton momentum fractions $x$ and its effect on the extracted parton polarizations. We find that different assumptions about $A_{LL}$ extrapolations and SU(3) symmetry can have significant consequences for the integrated quark and gluon polarizations, for polarized proton, deuteron and $^3$He beams. For the parity-violating asymmetry, $A_{UL}$, we study the potential impact on the polarized strange quark distribution with different extrapolations of $A_{UL}$, finding the constraining power to be ultimately limited by the EIC machine luminosity. |
2011.04711 | Anna Stasto | Michal Deak, Anna M. Stasto, Mark Strikman | High $|t|$ diffractive vector meson production at the EIC | 27 pages, 14 figures | Phys. Rev. D 103, 014022 (2021) | 10.1103/PhysRevD.103.014022 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate the prospects of the diffractive production of $J/\psi$ mesons
at large momentum transfer $|t|$ at the future Electron Ion Collider in
electron-proton collisions. In particular, we focus on the measurements of the
rapidity gap size. The model used for the calculations is based on the
diffractive exchange of the Balitsky-Fadin-Kuraev-Lipatov perturbative Pomeron.
Calculations for the cross section and the estimates for the rates assuming
integrated luminosity of $10 \, \rm fb^{-1}$ are provided. Two experimental
strategies were considered. First, measuring the rapidity gap size directly, by
observing the activity in the forward part of the central detector, and second
by putting a lower limit on the rapidity gap size in the case when the detector
cannot measure forward activity. We find that, it is possible to measure at the
EIC the dependence of the cross section on rapidity gap interval up to four
units in rapidity. This should allow to measure the change of the cross section
by a factor 1.6 expected due to the BFKL exchange. This is possible with the
present setup of the detector which projects the coverage up to 3.5 units of
rapidity. We conclude however, that the extension of the detector up to higher
rapidity, for example to 4.5 would be desirable and provide even better lever
arm for testing rapidity gap physics at the EIC.
| [
{
"created": "Mon, 9 Nov 2020 19:40:33 GMT",
"version": "v1"
}
] | 2021-01-27 | [
[
"Deak",
"Michal",
""
],
[
"Stasto",
"Anna M.",
""
],
[
"Strikman",
"Mark",
""
]
] | We investigate the prospects of the diffractive production of $J/\psi$ mesons at large momentum transfer $|t|$ at the future Electron Ion Collider in electron-proton collisions. In particular, we focus on the measurements of the rapidity gap size. The model used for the calculations is based on the diffractive exchange of the Balitsky-Fadin-Kuraev-Lipatov perturbative Pomeron. Calculations for the cross section and the estimates for the rates assuming integrated luminosity of $10 \, \rm fb^{-1}$ are provided. Two experimental strategies were considered. First, measuring the rapidity gap size directly, by observing the activity in the forward part of the central detector, and second by putting a lower limit on the rapidity gap size in the case when the detector cannot measure forward activity. We find that, it is possible to measure at the EIC the dependence of the cross section on rapidity gap interval up to four units in rapidity. This should allow to measure the change of the cross section by a factor 1.6 expected due to the BFKL exchange. This is possible with the present setup of the detector which projects the coverage up to 3.5 units of rapidity. We conclude however, that the extension of the detector up to higher rapidity, for example to 4.5 would be desirable and provide even better lever arm for testing rapidity gap physics at the EIC. |
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