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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1601.06232 | Sibo Zheng | Huayong Han, Jin Min Yang, Yang Zhang and Sibo Zheng | Collider Signatures of Higgs-portal Scalar Dark Matter | 11 pages, 4 figures; v2: minor changes, references added, journal
version | Phys.Lett.B756 (2016) 109 | 10.1016/j.physletb.2016.03.010 | null | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the simplest Higgs-portal scalar dark matter model, the dark matter mass
has been restricted to be either near the resonant mass ($m_h/2$) or in a
large-mass region by the direct detection at LHC Run 1 and LUX. While the
large-mass region below roughly 3 TeV can be probed by the future Xenon1T
experiment, most of the resonant mass region is beyond the scope of Xenon1T. In
this paper, we study the direct detection of such scalar dark matter in the
narrow resonant mass region at the 14 TeV LHC and the future 100 TeV hadron
collider. We show the luminosities required for the $2\sigma$ exclusion and
$5\sigma$ discovery.
| [
{
"created": "Sat, 23 Jan 2016 04:59:20 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Mar 2016 05:21:42 GMT",
"version": "v2"
}
] | 2016-03-16 | [
[
"Han",
"Huayong",
""
],
[
"Yang",
"Jin Min",
""
],
[
"Zhang",
"Yang",
""
],
[
"Zheng",
"Sibo",
""
]
] | In the simplest Higgs-portal scalar dark matter model, the dark matter mass has been restricted to be either near the resonant mass ($m_h/2$) or in a large-mass region by the direct detection at LHC Run 1 and LUX. While the large-mass region below roughly 3 TeV can be probed by the future Xenon1T experiment, most of the resonant mass region is beyond the scope of Xenon1T. In this paper, we study the direct detection of such scalar dark matter in the narrow resonant mass region at the 14 TeV LHC and the future 100 TeV hadron collider. We show the luminosities required for the $2\sigma$ exclusion and $5\sigma$ discovery. |
hep-ph/0110372 | Pene | A. Le Yaouanc, L. Oliver, O. Pene, J.-C. Raynal and V. Morenas | Remarks on sum rules in the heavy quark limit of QCD | Contribution to the International Europhysics Conference on HEP,
Budapest, July 2001 (presented by L. Oliver); 5 pages | null | null | LPT-Orsay 01-106 | hep-ph | null | We underline a problem existing in the heavy quark limit of QCD concerning
the rates of semileptonic B decays into P-wave $D_J(j)$ mesons, where $j = {1
\over 2}$ (wide states) or $j = {3 \over 2}$ (narrow states). The leading order
sum rules of Bjorken and Uraltsev suggest $\Gamma [ \bar{B} \to D_{0,1} ({1
\over 2}) \ell \nu ] \ll \Gamma [ \bar{B} \to D_{1,2} ({3 \over 2}) \ell \nu
]$, in contradiction with experiment. The same trend follows also from a sum
rule for the subleading $1/m_Q$ curent matrix element correction $\xi_3(1)$.
The problem is made explicit in relativistic quarks models \`a la Bakamjian and
Thomas, that give a transparent physical interpretation of the latter as due,
not to a $L \cdot S$ force, but to the Wigner rotation of the light quark spin.
We point out moreover that the selection rule for decay constants of $j = {3
\over 2}$ states, $f_{3/2} = 0$, predicts, assuming the model of factorization,
the opposite hierarchy $\Gamma [ \bar{B} \to \bar{D}_{s_{1,2}} ({3 \over 2})
D^{(*)} ] \ll \Gamma [ \bar{B} \to \bar{D}_{s_{0,1}} ({1 \over 2}) D^{(*)} ]$.
| [
{
"created": "Mon, 29 Oct 2001 16:17:31 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Yaouanc",
"A. Le",
""
],
[
"Oliver",
"L.",
""
],
[
"Pene",
"O.",
""
],
[
"Raynal",
"J. -C.",
""
],
[
"Morenas",
"V.",
""
]
] | We underline a problem existing in the heavy quark limit of QCD concerning the rates of semileptonic B decays into P-wave $D_J(j)$ mesons, where $j = {1 \over 2}$ (wide states) or $j = {3 \over 2}$ (narrow states). The leading order sum rules of Bjorken and Uraltsev suggest $\Gamma [ \bar{B} \to D_{0,1} ({1 \over 2}) \ell \nu ] \ll \Gamma [ \bar{B} \to D_{1,2} ({3 \over 2}) \ell \nu ]$, in contradiction with experiment. The same trend follows also from a sum rule for the subleading $1/m_Q$ curent matrix element correction $\xi_3(1)$. The problem is made explicit in relativistic quarks models \`a la Bakamjian and Thomas, that give a transparent physical interpretation of the latter as due, not to a $L \cdot S$ force, but to the Wigner rotation of the light quark spin. We point out moreover that the selection rule for decay constants of $j = {3 \over 2}$ states, $f_{3/2} = 0$, predicts, assuming the model of factorization, the opposite hierarchy $\Gamma [ \bar{B} \to \bar{D}_{s_{1,2}} ({3 \over 2}) D^{(*)} ] \ll \Gamma [ \bar{B} \to \bar{D}_{s_{0,1}} ({1 \over 2}) D^{(*)} ]$. |
hep-ph/9504264 | Manfried Faber | M. Faber, O. Borisenko, G. Zinovjev | Triality in QCD at Zero and Finite Temperature: A New Direction | 15 pages, latex, no figures, to appear in Nucl.Phys.B | Nucl.Phys.B444:563-576,1995 | 10.1016/0550-3213(95)00164-N | IK-TUW-Preprint 9501402 | hep-ph hep-lat hep-th | null | Discrete symmetries in grand canonical ensembles and in ensembles canonical
with respect to triality are investigated. We speculate about the general phase
structure of finite temperature gauge theories with discrete $Z(N)$ symmetry.
Low and high temperature phases turn out to be different in both ensembles even
for infinite systems. It is argued that gauge theories with matter fields in
the fundamental representation should be treated in ensembles canonical with
respect to triality if one wants to avoid unphysical predictions. Further, we
discuss as a physical consequence of such a treatment the impossibility of the
existence of metastable phases in the quark-gluon plasma.
| [
{
"created": "Mon, 10 Apr 1995 13:22:15 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Faber",
"M.",
""
],
[
"Borisenko",
"O.",
""
],
[
"Zinovjev",
"G.",
""
]
] | Discrete symmetries in grand canonical ensembles and in ensembles canonical with respect to triality are investigated. We speculate about the general phase structure of finite temperature gauge theories with discrete $Z(N)$ symmetry. Low and high temperature phases turn out to be different in both ensembles even for infinite systems. It is argued that gauge theories with matter fields in the fundamental representation should be treated in ensembles canonical with respect to triality if one wants to avoid unphysical predictions. Further, we discuss as a physical consequence of such a treatment the impossibility of the existence of metastable phases in the quark-gluon plasma. |
1211.1976 | Felix Yu | Wolfgang Altmannshofer, Marcela Carena, Nausheen R. Shah, Felix Yu | Indirect Probes of the MSSM after the Higgs Discovery | 28 pages, 15 figures; v2, updated with new LHCb and direct A->tau tau
results from HCP 2012, references added | null | 10.1007/JHEP01(2013)160 | EFI-12-30; FERMILAB-PUB-12-590-T; MCTP-12-28 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the minimal supersymmetric standard model (MSSM) with minimal flavor
violation (MFV), imposing constraints from flavor physics observables and MSSM
Higgs searches, in light of the recent discovery of a 125 GeV Higgs boson by
ATLAS and CMS. We analyze the electroweak vacuum stability conditions to
further restrict the MSSM parameter space. In addition, a connection to
ultraviolet physics is shown via an implementation of renormalization group
running, which determines the TeV-scale spectrum from a small set of minimal
supergravity parameters. Finally, we investigate the impact from dark matter
direct detection searches. Our work highlights the complementarity of collider,
flavor and dark matter probes in exploring the MSSM, and shows that even in a
MFV framework, flavor observables constrain the MSSM parameter space well
beyond the current reach of direct SUSY particle searches.
| [
{
"created": "Thu, 8 Nov 2012 21:00:05 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Dec 2012 18:08:31 GMT",
"version": "v2"
}
] | 2013-02-22 | [
[
"Altmannshofer",
"Wolfgang",
""
],
[
"Carena",
"Marcela",
""
],
[
"Shah",
"Nausheen R.",
""
],
[
"Yu",
"Felix",
""
]
] | We study the minimal supersymmetric standard model (MSSM) with minimal flavor violation (MFV), imposing constraints from flavor physics observables and MSSM Higgs searches, in light of the recent discovery of a 125 GeV Higgs boson by ATLAS and CMS. We analyze the electroweak vacuum stability conditions to further restrict the MSSM parameter space. In addition, a connection to ultraviolet physics is shown via an implementation of renormalization group running, which determines the TeV-scale spectrum from a small set of minimal supergravity parameters. Finally, we investigate the impact from dark matter direct detection searches. Our work highlights the complementarity of collider, flavor and dark matter probes in exploring the MSSM, and shows that even in a MFV framework, flavor observables constrain the MSSM parameter space well beyond the current reach of direct SUSY particle searches. |
2302.03002 | Alexander Bednyakov | A. V. Bednyakov, and A. I. Mukhaeva | Impact of a non-universal $Z^\prime$ on the $B\to K^{(*)}l^+l^-$ and $B
\to K^{(*)}\nu\bar{\nu}$ processes | 14 pages, 4 figures, references updated. arXiv admin note: text
overlap with arXiv:2207.10613 by other authors | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a study of the new physics effects in semileptonic FCNC processes
within a low-energy approximation of the anomaly-free supersymmetic extension
of the SM with additional $Z'$ vector field. The key feature of the model is
the non-diagonal structure of $Z'$ couplings to fermions, which is
parameterized by few new-physics parameters in addition to well-known mixing
matrices for quarks and leptons in the SM. We not only consider CP-conserving
scenarios with real parameters, but also account for possible CP violation due
to new physical weak phases. We analyse the dependence of the $b\to s$
observables on the parameters together with correlations between the
observables predicted in the model. Special attention is paid to possible
enhancement of $B \to K^{(*)} \nu\bar{\nu}$ rates and to CP-odd angular
observables in $B \to K^* ll$ decays.
| [
{
"created": "Fri, 13 Jan 2023 08:40:26 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Mar 2023 13:38:23 GMT",
"version": "v2"
}
] | 2023-03-06 | [
[
"Bednyakov",
"A. V.",
""
],
[
"Mukhaeva",
"A. I.",
""
]
] | We perform a study of the new physics effects in semileptonic FCNC processes within a low-energy approximation of the anomaly-free supersymmetic extension of the SM with additional $Z'$ vector field. The key feature of the model is the non-diagonal structure of $Z'$ couplings to fermions, which is parameterized by few new-physics parameters in addition to well-known mixing matrices for quarks and leptons in the SM. We not only consider CP-conserving scenarios with real parameters, but also account for possible CP violation due to new physical weak phases. We analyse the dependence of the $b\to s$ observables on the parameters together with correlations between the observables predicted in the model. Special attention is paid to possible enhancement of $B \to K^{(*)} \nu\bar{\nu}$ rates and to CP-odd angular observables in $B \to K^* ll$ decays. |
hep-ph/0302090 | Yu. A. Simonov | Yu.A. Simonov (ITEP, Moscow) | Resolution of the pion puzzle: the QCD string in Nambu-Goldstone mesons | 20 pages, no figures; v2: minor corrections | Phys.Atom.Nucl. 67 (2004) 846-855; Yad.Fiz. 67 (2004) 868-877 | 10.1134/1.1707145 | null | hep-ph | null | Pions and kaons have double nature: the chiral dynamics of Nambu-Goldstone
bosons together with the usual string dynamics common to all mesons. To uncover
the interplay of both dynamics the effective chiral Lagrangian is derived from
the QCD Lagrangian using the Field Correlator Method and the pion self-energy
(mass) operator is written explicitly. The latter contains an infinite number
of poles, but normalized to zero at zero momentum because of spontaneous chiral
symmetry breaking. As a result one obtains the Gell-Mann-Oakes-Renner relation
for the ground state pion and (slightly shifted by chiral dynamics) the usual
spectrum of radially excited pions starting with $\pi(1300)$.
| [
{
"created": "Wed, 12 Feb 2003 13:55:06 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Jul 2003 17:49:49 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Simonov",
"Yu. A.",
"",
"ITEP, Moscow"
]
] | Pions and kaons have double nature: the chiral dynamics of Nambu-Goldstone bosons together with the usual string dynamics common to all mesons. To uncover the interplay of both dynamics the effective chiral Lagrangian is derived from the QCD Lagrangian using the Field Correlator Method and the pion self-energy (mass) operator is written explicitly. The latter contains an infinite number of poles, but normalized to zero at zero momentum because of spontaneous chiral symmetry breaking. As a result one obtains the Gell-Mann-Oakes-Renner relation for the ground state pion and (slightly shifted by chiral dynamics) the usual spectrum of radially excited pions starting with $\pi(1300)$. |
hep-ph/0111246 | David London | Karine Leroux and David London | Flavour-Changing Neutral Currents and Leptophobic Z' Gauge Bosons | 11 pages, LaTeX, no figures | Phys.Lett.B526:97-103,2002 | 10.1016/S0370-2693(01)01489-7 | UdeM-GPP-TH-01-91 | hep-ph | null | Leptophobic Z' gauge bosons can appear in models with an E_6 gauge symmetry.
We show that flavour-changing neutral currents can be generated in some of
these models due to the mixing of the ordinary d_R, s_R and b_R quark fields
with the exotic h_R. Because the Z' does not couple to charged leptons, the
constraints on the flavour-changing couplings U^{Z'}_{db} and U^{Z'}_{sb} are
relatively weak. Indeed, B_q--Bbar_q mixing (q=d,s) can be dominated by Z'
exchange, which will affect CP-violating rate asymmetries in B decays. Rare
hadronic B decays can also be affected, while decays involving charged leptons
will be unchanged.
| [
{
"created": "Tue, 20 Nov 2001 16:02:45 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"Leroux",
"Karine",
""
],
[
"London",
"David",
""
]
] | Leptophobic Z' gauge bosons can appear in models with an E_6 gauge symmetry. We show that flavour-changing neutral currents can be generated in some of these models due to the mixing of the ordinary d_R, s_R and b_R quark fields with the exotic h_R. Because the Z' does not couple to charged leptons, the constraints on the flavour-changing couplings U^{Z'}_{db} and U^{Z'}_{sb} are relatively weak. Indeed, B_q--Bbar_q mixing (q=d,s) can be dominated by Z' exchange, which will affect CP-violating rate asymmetries in B decays. Rare hadronic B decays can also be affected, while decays involving charged leptons will be unchanged. |
hep-ph/9910448 | Markus Wobisch | C. Duprel, Th. Hadig, N. Kauer, M. Wobisch | Comparison of Next-to-Leading Order Calculations for Jet Cross Sections
in Deep-Inelastic Scattering | 9 pages, to appear in: Proceedings of the Workshop on Monte Carlo
Generators for HERA Physics | null | null | MADPH-99-1129, PITHA 99/30 | hep-ph | null | We compare different next-to-leading order calculations of jet cross sections
in deep-inelastic scattering as implemented in the programs DISASTER++, DISENT,
JETVIP and MEPJET. In all phase space regions under study DISENT and DISASTER++
agree better than 2%. MEPJET shows systematic deviations of being typically
5-8% lower than the other programs. The JETVIP results show a significant
dependence on the phase space slicing parameter $y_{\rm cut}$. In the cases
where the $y_{\rm cut}$ dependence within $10^{-4} \le y_{\rm cut} \le 10^{-3}$
is smaller than 3% the JETVIP results are often comparable with the DISENT and
DISASTER++ results.
| [
{
"created": "Fri, 22 Oct 1999 15:03:22 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Duprel",
"C.",
""
],
[
"Hadig",
"Th.",
""
],
[
"Kauer",
"N.",
""
],
[
"Wobisch",
"M.",
""
]
] | We compare different next-to-leading order calculations of jet cross sections in deep-inelastic scattering as implemented in the programs DISASTER++, DISENT, JETVIP and MEPJET. In all phase space regions under study DISENT and DISASTER++ agree better than 2%. MEPJET shows systematic deviations of being typically 5-8% lower than the other programs. The JETVIP results show a significant dependence on the phase space slicing parameter $y_{\rm cut}$. In the cases where the $y_{\rm cut}$ dependence within $10^{-4} \le y_{\rm cut} \le 10^{-3}$ is smaller than 3% the JETVIP results are often comparable with the DISENT and DISASTER++ results. |
1504.00315 | Mirko Serino | A. van Hameren and M. Serino | BCFW recursion for TMD parton scattering | Some typos in text and formulas corrected | JHEP 1507 (2015) 010 | 10.1007/JHEP07(2015)010 | IFJPAN-IV-2015-5 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the application of the BCFW recursion relation to scattering
amplitudes with one off-shell particle in a Yang-Mills theory with fermions. We
provide a set of conditions of applicability of the BCFW recursion, stressing
some important differences with respect to the pure on-shell case. We show how
the formulas for Maximally-Helicity-Violating (MHV) configurations with any
number of partons, which are well known in the fully on-shell case, are
generalized to this kinematic regime. We also derive analytic expressions for
all the helicity configurations of the 5-point color-stripped tree-level
amplitudes for any of the partons being off the mass shell.
| [
{
"created": "Wed, 1 Apr 2015 17:51:20 GMT",
"version": "v1"
},
{
"created": "Sat, 13 Jun 2015 22:16:11 GMT",
"version": "v2"
},
{
"created": "Wed, 1 Jul 2015 14:32:38 GMT",
"version": "v3"
},
{
"created": "Mon, 27 Jul 2015 07:49:05 GMT",
"version": "v4"
},
{
"cre... | 2016-11-15 | [
[
"van Hameren",
"A.",
""
],
[
"Serino",
"M.",
""
]
] | We investigate the application of the BCFW recursion relation to scattering amplitudes with one off-shell particle in a Yang-Mills theory with fermions. We provide a set of conditions of applicability of the BCFW recursion, stressing some important differences with respect to the pure on-shell case. We show how the formulas for Maximally-Helicity-Violating (MHV) configurations with any number of partons, which are well known in the fully on-shell case, are generalized to this kinematic regime. We also derive analytic expressions for all the helicity configurations of the 5-point color-stripped tree-level amplitudes for any of the partons being off the mass shell. |
hep-ph/0303009 | Markus H. Thoma | Purnendu Chakraborty, Munshi G. Mustafa, Markus H. Thoma | Quark Number Susceptibility, Thermodynamic Sum Rule, and Hard Thermal
Loop Approximation | 4 pages, 2 figures, final version to be published in Phys. Rev. D | Phys.Rev. D68 (2003) 085012 | 10.1103/PhysRevD.68.085012 | null | hep-ph nucl-th | null | The quark number susceptibility, associated with the conserved quark number
density, is closely related to the baryon and charge fluctuations in the
quark-gluon plasma, which might serve as signature for the quark-gluon plasma
formation in ultrarelativistic heavy-ion collisions. Beside QCD lattice
simulations, the quark number susceptibility has been calculated recently using
a resummed perturbation theory (Hard Thermal Loop resummation). In the present
work we show, based on general arguments, that the computation of this quantity
neglecting Hard Thermal Loop vertices contradicts the Ward identity and
violates the thermodynamic sum rule following from the quark number
conservation. We further show that the Hard Thermal Loop perturbation theory is
consistent with the thermodynamic sum rule.
| [
{
"created": "Mon, 3 Mar 2003 12:02:31 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Sep 2003 14:29:59 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Chakraborty",
"Purnendu",
""
],
[
"Mustafa",
"Munshi G.",
""
],
[
"Thoma",
"Markus H.",
""
]
] | The quark number susceptibility, associated with the conserved quark number density, is closely related to the baryon and charge fluctuations in the quark-gluon plasma, which might serve as signature for the quark-gluon plasma formation in ultrarelativistic heavy-ion collisions. Beside QCD lattice simulations, the quark number susceptibility has been calculated recently using a resummed perturbation theory (Hard Thermal Loop resummation). In the present work we show, based on general arguments, that the computation of this quantity neglecting Hard Thermal Loop vertices contradicts the Ward identity and violates the thermodynamic sum rule following from the quark number conservation. We further show that the Hard Thermal Loop perturbation theory is consistent with the thermodynamic sum rule. |
0907.1560 | Shaaban Khalil | Shaaban Khalil | Lepton flavor violation in supersymmetric B-L extension of the standard
model | 17 pages | null | 10.1103/PhysRevD.81.035002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Supersymmetric B-L extension of the Standard Model (SM) is one of the best
candidate for physics beyond the SM that accounts for TeV scale seesaw
mechanism and provides an attractive solution for the Higgs naturalness
problem. We analyze the charged lepton flavor violation (LFV) in this class of
models. We show that due to the smallness of Dirac neutrino Yukawa coupling,
the decay rates of l_i -> l_j gamma and l_i -> 3 l_j, generated by the
renormalization group evolution of soft SUSY breaking terms from GUT to seesaw
scale, are quite suppressed. Therefore, this model is free from the stringent
LFV constraints usually imposed on the supersymmetric seesaw model. We also
demonstrate that the right-sneutrino is a long-lived particle and can be pair
produced at the LHC through the B-L gauge boson. Then, they decay into
same-sign dilepton, with a total cross section of order O(1) pb. This signal is
one of the striking signatures of supersymmetric B-L extension of the SM.
| [
{
"created": "Thu, 9 Jul 2009 14:32:00 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Jan 2010 08:56:33 GMT",
"version": "v2"
}
] | 2013-05-29 | [
[
"Khalil",
"Shaaban",
""
]
] | Supersymmetric B-L extension of the Standard Model (SM) is one of the best candidate for physics beyond the SM that accounts for TeV scale seesaw mechanism and provides an attractive solution for the Higgs naturalness problem. We analyze the charged lepton flavor violation (LFV) in this class of models. We show that due to the smallness of Dirac neutrino Yukawa coupling, the decay rates of l_i -> l_j gamma and l_i -> 3 l_j, generated by the renormalization group evolution of soft SUSY breaking terms from GUT to seesaw scale, are quite suppressed. Therefore, this model is free from the stringent LFV constraints usually imposed on the supersymmetric seesaw model. We also demonstrate that the right-sneutrino is a long-lived particle and can be pair produced at the LHC through the B-L gauge boson. Then, they decay into same-sign dilepton, with a total cross section of order O(1) pb. This signal is one of the striking signatures of supersymmetric B-L extension of the SM. |
hep-ph/9510390 | Ulf Meissner | Ulf-G. Mei{\ss}ner | The Reaction $\pi N \to \pi \pi N$ at Threshold | 4 pp, LaTeX, Invited talk, BARYONS' 95, Santa Fe, October 1995, to
appear in the Proceedings | null | null | TK 95 29 | hep-ph nucl-th | null | I summarize the results of the complete one--loop chiral perturbation theory
calculation performed recently. It is shown that it allows to accurately pin
down the isospin two, S--wave $\pi \pi$ scattering length $a_0^2$. On the other
hand, interesting resonance physics makes a precise determination of $a_0^0$
very difficult.
| [
{
"created": "Tue, 24 Oct 1995 15:33:53 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Meißner",
"Ulf-G.",
""
]
] | I summarize the results of the complete one--loop chiral perturbation theory calculation performed recently. It is shown that it allows to accurately pin down the isospin two, S--wave $\pi \pi$ scattering length $a_0^2$. On the other hand, interesting resonance physics makes a precise determination of $a_0^0$ very difficult. |
hep-ph/0111392 | Zoltan Ligeti | Benjamin Grinstein and Zoltan Ligeti | Heavy quark symmetry in B -> D(*) ell nu spectra | 14 pages | Phys.Lett.B526:345-354,2002; Erratum-ibid.B601:236-237,2004 | 10.1016/S0370-2693(01)01517-9 | LBNL-49173, UCSD/PTH 01-20 | hep-ph hep-ex | null | We calculate heavy quark symmetry breaking in the slopes and curvatures of
the $B\to D^{(*)}\ell\bar\nu$ spectra at zero recoil, including the order
$\alpha_s^2\beta_0$ corrections. We point out that the theoretical
uncertainties in the differences between $B\to D$ and $B\to D^*$ slopes and
curvatures are smaller than in the deviations of the slopes and curvatures
themselves from their infinite mass limits. We find that the central values of
the current experimental results for the difference of the slopes differ from
our calculations when QCD sum rules are used to estimate subleading Isgur-Wise
functions. A better understanding of the shapes of the $B\to
D^{(*)}\ell\bar\nu$ spectra may also help to reduce the error of $|V_{cb}|$
extracted from the zero recoil limit of $B\to D^*\ell\bar\nu$. We argue that
heavy quark symmetry requires that the same fitting procedure be used in the
experimental determinations of the shape parameters and $|V_{cb}|$ from the
$B\to D\ell\bar\nu$ and $B\to D^{*}\ell\bar\nu$ spectra.
| [
{
"created": "Thu, 29 Nov 2001 03:10:00 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Feb 2004 23:37:33 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Grinstein",
"Benjamin",
""
],
[
"Ligeti",
"Zoltan",
""
]
] | We calculate heavy quark symmetry breaking in the slopes and curvatures of the $B\to D^{(*)}\ell\bar\nu$ spectra at zero recoil, including the order $\alpha_s^2\beta_0$ corrections. We point out that the theoretical uncertainties in the differences between $B\to D$ and $B\to D^*$ slopes and curvatures are smaller than in the deviations of the slopes and curvatures themselves from their infinite mass limits. We find that the central values of the current experimental results for the difference of the slopes differ from our calculations when QCD sum rules are used to estimate subleading Isgur-Wise functions. A better understanding of the shapes of the $B\to D^{(*)}\ell\bar\nu$ spectra may also help to reduce the error of $|V_{cb}|$ extracted from the zero recoil limit of $B\to D^*\ell\bar\nu$. We argue that heavy quark symmetry requires that the same fitting procedure be used in the experimental determinations of the shape parameters and $|V_{cb}|$ from the $B\to D\ell\bar\nu$ and $B\to D^{*}\ell\bar\nu$ spectra. |
hep-ph/9809247 | Bryan Webber | Mrinal Dasgupta and Bryan R. Webber | Two-loop enhancement factor for 1/Q corrections to event shapes in deep
inelastic scattering | 15 pages, 1 figure, uses JHEP.cls. This revised version corrects an
error in the calculation of the enhancement factor. The main conclusions
remain unchanged | JHEP 9810:001,1998 | 10.1088/1126-6708/1998/10/001 | Cavendish-HEP-98/02 | hep-ph | null | We compute the two-loop enhancement factors for our earlier one-loop
calculations of leading (1/Q) power corrections to the mean values of some
event shape variables in deep inelastic lepton scattering. The enhancement is
found to be equal to the universal ``Milan factor'' for those shape variables
considered, provided the one-loop calculation is performed in a particular way.
As a result, the phenomenology of power corrections to DIS event shapes remains
largely unaffected.
| [
{
"created": "Thu, 3 Sep 1998 15:30:41 GMT",
"version": "v1"
},
{
"created": "Sun, 22 Oct 2000 23:43:45 GMT",
"version": "v2"
}
] | 2010-02-03 | [
[
"Dasgupta",
"Mrinal",
""
],
[
"Webber",
"Bryan R.",
""
]
] | We compute the two-loop enhancement factors for our earlier one-loop calculations of leading (1/Q) power corrections to the mean values of some event shape variables in deep inelastic lepton scattering. The enhancement is found to be equal to the universal ``Milan factor'' for those shape variables considered, provided the one-loop calculation is performed in a particular way. As a result, the phenomenology of power corrections to DIS event shapes remains largely unaffected. |
hep-ph/0407027 | Yu. A. Simonov | Yu.A.Simonov | The matrix Hamiltonian for hadrons and the role of negative-energy
components | 29 pages, no figures | Phys.Atom.Nucl.68:709-722,2005; Yad.Fiz.68:739-752,2005 | 10.1134/1.1903098 | null | hep-ph | null | The world-line (Fock-Feynman-Schwinger) representation is used for quarks in
arbitrary (vacuum and valence gluon) field to construct the relativistic
Hamiltonian. After averaging the Green's function of the white $q\bar q$ system
over gluon fields one obtains the relativistic Hamiltonian, which is matrix in
spin indices and contains both positive and negative quark energies. The role
of the latter is studied in the example of the heavy-light meson and the
standard einbein technic is extended to the case of the matrix Hamiltonian.
Comparison with the Dirac equation shows a good agreement of the results. For
arbitrary $q\bar q $ system the nondiagonal matrix Hamiltonian components are
calculated through hyperfine interaction terms. A general discussion of the
role of negative energy components is given in conclusion.
| [
{
"created": "Fri, 2 Jul 2004 12:37:06 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Simonov",
"Yu. A.",
""
]
] | The world-line (Fock-Feynman-Schwinger) representation is used for quarks in arbitrary (vacuum and valence gluon) field to construct the relativistic Hamiltonian. After averaging the Green's function of the white $q\bar q$ system over gluon fields one obtains the relativistic Hamiltonian, which is matrix in spin indices and contains both positive and negative quark energies. The role of the latter is studied in the example of the heavy-light meson and the standard einbein technic is extended to the case of the matrix Hamiltonian. Comparison with the Dirac equation shows a good agreement of the results. For arbitrary $q\bar q $ system the nondiagonal matrix Hamiltonian components are calculated through hyperfine interaction terms. A general discussion of the role of negative energy components is given in conclusion. |
0805.1871 | Vladimir A Smirnov | Alexander V. Smirnov, Vladimir A. Smirnov, and Matthias Steinhauser | Applying Mellin-Barnes technique and Groebner bases to the three-loop
static potential | LaTeX, 5 pages with 1 figure | PoS RADCOR2007:024,2007 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Mellin-Barnes technique to evaluate master integrals and the algorithm
called FIRE to solve IBP relations with the help of Groebner bases are briefly
reviewed. In FIRE, an extension of the classical Buchberger algorithm to
construct Groebner bases is combined with the well-known Laporta algorithm. It
is explained how both techniques are used when evaluating the three-loop
correction to the static QCD quark potential. First results are presented: the
coefficients of n_l^3 and n_l^2, where n_l is the number of light quarks.
| [
{
"created": "Tue, 13 May 2008 15:23:35 GMT",
"version": "v1"
}
] | 2010-11-26 | [
[
"Smirnov",
"Alexander V.",
""
],
[
"Smirnov",
"Vladimir A.",
""
],
[
"Steinhauser",
"Matthias",
""
]
] | The Mellin-Barnes technique to evaluate master integrals and the algorithm called FIRE to solve IBP relations with the help of Groebner bases are briefly reviewed. In FIRE, an extension of the classical Buchberger algorithm to construct Groebner bases is combined with the well-known Laporta algorithm. It is explained how both techniques are used when evaluating the three-loop correction to the static QCD quark potential. First results are presented: the coefficients of n_l^3 and n_l^2, where n_l is the number of light quarks. |
1608.03388 | Arvind Kumar | Harpreet Singh, Arvind Kumar, Harleen Dahiya | Magnetic Moments of Octet Baryons in Hot and Dense Nuclear Matter | Accepted for Publication in Chinese Physics C | null | 10.1088/1674-1137/41/9/094104 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have calculated the in-medium magnetic moments of octet baryons in the
presence of hot and dense symmetric nuclear matter. Effective magnetic moments
of baryons have been derived from medium modified quark masses within chiral
SU(3) quark mean field model.
Further, for better insight of medium modification of baryonic magnetic
moments, we have considered the explicit contributions from the valence quarks,
sea quarks as well as sea orbital angular momentum of sea quarks. These effects
have been successful in giving the description of baryonic magnetic moments in
vacuum.
The magnetic moments of baryons are found to vary significantly as a function
of density of nuclear medium.
| [
{
"created": "Thu, 11 Aug 2016 07:16:04 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jun 2017 09:45:47 GMT",
"version": "v2"
}
] | 2017-07-03 | [
[
"Singh",
"Harpreet",
""
],
[
"Kumar",
"Arvind",
""
],
[
"Dahiya",
"Harleen",
""
]
] | We have calculated the in-medium magnetic moments of octet baryons in the presence of hot and dense symmetric nuclear matter. Effective magnetic moments of baryons have been derived from medium modified quark masses within chiral SU(3) quark mean field model. Further, for better insight of medium modification of baryonic magnetic moments, we have considered the explicit contributions from the valence quarks, sea quarks as well as sea orbital angular momentum of sea quarks. These effects have been successful in giving the description of baryonic magnetic moments in vacuum. The magnetic moments of baryons are found to vary significantly as a function of density of nuclear medium. |
1007.0808 | Sanjeev Kumar | Sanjeev Kumar | Unitarity constraints on trimaximal mixing | 15 pages, 10 figures, Physical Review D (to appear) | Phys.Rev.D82:013010,2010 | 10.1103/PhysRevD.82.013010 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | When the neutrino mass eigenstate $\nu_2$ is trimaximally mixed, the mixing
matrix is called trimaximal. The middle column of trimaximal mixing matrix is
identical to tri-bimaximal mixing and the other two columns are subject to
unitarity constraints. This corresponds to a mixing matrix with four
independent parameters in the most general case. Apart from the two Majorana
phases, the mixing matrix has only one free parameter in the CP conserving
limit. Trimaximality results into interesting interplay between mixing angles
and CP violation. A notion of maximal CP violation naturally emerges here: CP
violation is maximal for maximal 2-3 mixing. Similarly, there is a natural
constraint on the deviation from maximal 2-3 mixing which takes its maximal
value in the CP conserving limit.
| [
{
"created": "Tue, 6 Jul 2010 04:41:24 GMT",
"version": "v1"
}
] | 2013-08-02 | [
[
"Kumar",
"Sanjeev",
""
]
] | When the neutrino mass eigenstate $\nu_2$ is trimaximally mixed, the mixing matrix is called trimaximal. The middle column of trimaximal mixing matrix is identical to tri-bimaximal mixing and the other two columns are subject to unitarity constraints. This corresponds to a mixing matrix with four independent parameters in the most general case. Apart from the two Majorana phases, the mixing matrix has only one free parameter in the CP conserving limit. Trimaximality results into interesting interplay between mixing angles and CP violation. A notion of maximal CP violation naturally emerges here: CP violation is maximal for maximal 2-3 mixing. Similarly, there is a natural constraint on the deviation from maximal 2-3 mixing which takes its maximal value in the CP conserving limit. |
2208.14693 | Jiaqi Chen | Jiaqi Chen | Iteratively Reduce Auxiliary Scalar Product in Multi-loop Integrals | 12 pages, 1 table | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we construct a uniform formula that can iteratively reduce all
auxiliary scalar product numerators of arbitrary multi-loop Feynman integrals.
Integrals with such numerators commonly appear in Integration-By-Parts (IBP)
relations. This formula is constructed with the generalized Sylvester's
determinant identity. Compared to that using only traditional IBP reduction
method, the combination of the formula and the traditional IBP method shows a
significant speed-up.
| [
{
"created": "Wed, 31 Aug 2022 08:42:26 GMT",
"version": "v1"
}
] | 2022-09-01 | [
[
"Chen",
"Jiaqi",
""
]
] | In this paper, we construct a uniform formula that can iteratively reduce all auxiliary scalar product numerators of arbitrary multi-loop Feynman integrals. Integrals with such numerators commonly appear in Integration-By-Parts (IBP) relations. This formula is constructed with the generalized Sylvester's determinant identity. Compared to that using only traditional IBP reduction method, the combination of the formula and the traditional IBP method shows a significant speed-up. |
1904.09993 | Antonio Enrique C\'arcamo Hern\'andez | A. E. C\'arcamo Hern\'andez, Juan Marchant Gonz\'alez, U. J.
Salda\~na-Salazar | Viable low-scale model with Universal and Inverse Seesaw Mechanisms | Version accepted for publication in PRD | Phys. Rev. D 100, 035024 (2019) | 10.1103/PhysRevD.100.035024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We formulate a viable low-scale seesaw model, where the masses for the
standard model (SM) charged fermions lighter than the top quark emerge from a
universal seesaw mechanism mediated by charged vectorlike fermions. The small
light active neutrino masses are produced from an inverse seesaw mechanism
mediated by right-handed Majorana neutrinos. Our model is based on the $A_{4} $
family symmetry, supplemented by cyclic symmetries, whose spontaneous breaking
produces the observed pattern of SM fermion masses and mixings. The model can
accommodate the muon and electron anomalous magnetic dipole moments and
predicts strongly suppressed $\mu\rightarrow e\gamma $ and $\tau\rightarrow \mu
\gamma $ decay rates, but allows a $\tau \rightarrow e\gamma $ decay within the
reach of the forthcoming experiments.
| [
{
"created": "Mon, 22 Apr 2019 18:00:02 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Aug 2019 16:04:09 GMT",
"version": "v2"
}
] | 2019-09-04 | [
[
"Hernández",
"A. E. Cárcamo",
""
],
[
"González",
"Juan Marchant",
""
],
[
"Saldaña-Salazar",
"U. J.",
""
]
] | We formulate a viable low-scale seesaw model, where the masses for the standard model (SM) charged fermions lighter than the top quark emerge from a universal seesaw mechanism mediated by charged vectorlike fermions. The small light active neutrino masses are produced from an inverse seesaw mechanism mediated by right-handed Majorana neutrinos. Our model is based on the $A_{4} $ family symmetry, supplemented by cyclic symmetries, whose spontaneous breaking produces the observed pattern of SM fermion masses and mixings. The model can accommodate the muon and electron anomalous magnetic dipole moments and predicts strongly suppressed $\mu\rightarrow e\gamma $ and $\tau\rightarrow \mu \gamma $ decay rates, but allows a $\tau \rightarrow e\gamma $ decay within the reach of the forthcoming experiments. |
1901.01542 | Chen Rui | Fu-Lai Wang, Rui Chen, Zhan-Wei Liu, and Xiang Liu | Possible triple-charm molecular pentaquarks from
$\Xi_{cc}D_1/\Xi_{cc}D_2^*$ interactions | 10 pages, 5 figures, Accepted by PRD | Phys. Rev. D 99, 054021 (2019) | 10.1103/PhysRevD.99.054021 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we explore a systematic investigation on $S$-wave interactions
between a doubly charmed baryon $\Xi_{cc}(3621)$ and a charmed meson in a $T$
doublet $(D_1,\,D_2^*)$. We first analyze the possibility for forming
$\Xi_{cc}D_1/\Xi_{cc}D_2^*$ bound states with the heavy quark spin symmetry.
Then, we further perform a dynamical study on the $\Xi_{cc}D_1/\Xi_{cc}D_2^*$
interactions within a one-boson-exchange model by considering both the $S$-$D$
wave mixing and coupled channel effect. Finally, our numerical results conform
the proposals from the heavy quark spin symmetry analysis: the $\Xi_{cc}D_1$
systems with $I(J^P)=$ $0(1/2^+,\,3/2^+)$ and the $\Xi_{cc}D_2^*$ systems with
$I(J^P)=$ $0(3/2^+,\,5/2^+)$ can possibly be loose triple-charm molecular
pentaquarks. Meanwhile, we also extend our model to the $\Xi_{cc}\bar{D}_1$ and
$\Xi_{cc}\bar D_2^*$ systems, and our results indicate the isoscalars of
$\Xi_{cc}\bar{D}_1$ and $\Xi_{cc}\bar{D}_2^*$ can be possible molecular
candidates.
| [
{
"created": "Sun, 6 Jan 2019 13:48:57 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Mar 2019 08:09:46 GMT",
"version": "v2"
}
] | 2019-04-03 | [
[
"Wang",
"Fu-Lai",
""
],
[
"Chen",
"Rui",
""
],
[
"Liu",
"Zhan-Wei",
""
],
[
"Liu",
"Xiang",
""
]
] | In this work, we explore a systematic investigation on $S$-wave interactions between a doubly charmed baryon $\Xi_{cc}(3621)$ and a charmed meson in a $T$ doublet $(D_1,\,D_2^*)$. We first analyze the possibility for forming $\Xi_{cc}D_1/\Xi_{cc}D_2^*$ bound states with the heavy quark spin symmetry. Then, we further perform a dynamical study on the $\Xi_{cc}D_1/\Xi_{cc}D_2^*$ interactions within a one-boson-exchange model by considering both the $S$-$D$ wave mixing and coupled channel effect. Finally, our numerical results conform the proposals from the heavy quark spin symmetry analysis: the $\Xi_{cc}D_1$ systems with $I(J^P)=$ $0(1/2^+,\,3/2^+)$ and the $\Xi_{cc}D_2^*$ systems with $I(J^P)=$ $0(3/2^+,\,5/2^+)$ can possibly be loose triple-charm molecular pentaquarks. Meanwhile, we also extend our model to the $\Xi_{cc}\bar{D}_1$ and $\Xi_{cc}\bar D_2^*$ systems, and our results indicate the isoscalars of $\Xi_{cc}\bar{D}_1$ and $\Xi_{cc}\bar{D}_2^*$ can be possible molecular candidates. |
hep-ph/0101092 | Yael Shadmi | Michael Dine, Erik Kramer, Yosef Nir, and Yael Shadmi | CP Violation and the Scale of Supersymmetry Breaking | 22 pages, harvmac | Phys.Rev.D63:116005,2001 | 10.1103/PhysRevD.63.116005 | SCIPP-01/03, WIS/01/01-Jan-DPP | hep-ph | null | Supersymmetric models with a high supersymmetry breaking scale give, in
general, large contributions to epsilon_K and/or to various electric dipole
moments, even when contributions to CP conserving, flavor changing processes
are sufficiently suppressed. Some examples are models of dilaton dominance,
alignment, non-Abelian flavor symmetries, heavy first two generation sfermions,
anomaly mediation and gaugino mediation. There is then strong motivation for
`approximate CP', that is a situation where all CP violating phases are small.
In contrast, in supersymmetric models with a low breaking scale it is quite
plausible that the CKM matrix is the only source of flavor and CP violation.
Gauge mediation provides a concrete example. Approximate CP is then
unacceptable. Upcoming measurements of the CP asymmetry in B to \psi K_S might
exclude or support the idea of approximate CP and consequently probe the scale
of supersymmetry breaking.
| [
{
"created": "Wed, 10 Jan 2001 09:29:27 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Dine",
"Michael",
""
],
[
"Kramer",
"Erik",
""
],
[
"Nir",
"Yosef",
""
],
[
"Shadmi",
"Yael",
""
]
] | Supersymmetric models with a high supersymmetry breaking scale give, in general, large contributions to epsilon_K and/or to various electric dipole moments, even when contributions to CP conserving, flavor changing processes are sufficiently suppressed. Some examples are models of dilaton dominance, alignment, non-Abelian flavor symmetries, heavy first two generation sfermions, anomaly mediation and gaugino mediation. There is then strong motivation for `approximate CP', that is a situation where all CP violating phases are small. In contrast, in supersymmetric models with a low breaking scale it is quite plausible that the CKM matrix is the only source of flavor and CP violation. Gauge mediation provides a concrete example. Approximate CP is then unacceptable. Upcoming measurements of the CP asymmetry in B to \psi K_S might exclude or support the idea of approximate CP and consequently probe the scale of supersymmetry breaking. |
1705.01872 | Peihong Gu | Pei-Hong Gu, Rabindra N. Mohapatra | Quark Seesaw, Dark $U(1)$ symmetry and Baryon-Dark Matter Coincidence | 7 pages. Minor corrections and improvements. Accepted by PRD | Phys. Rev. D 96, 055011 (2017) | 10.1103/PhysRevD.96.055011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We attempt to understand the baryon-dark-matter coincidence problem within
the quark seesaw extension of the standard model where parity invariance is
used to solve the strong CP problem. The $SU(2)_L\times SU(2)_R\times
U(1)_{B-L}$ gauge symmetry of this model is extended by a dark $U(1)_X$ group
plus inclusion of a heavy neutral vector-like fermion $\chi_{L,R}$ charged
under the dark group which plays the role of dark matter. All fermions are
Dirac type in this model. Decay of heavy scalars charged under $U(1)_X$ leads
to simultaneous asymmetry generation of the dark matter and baryons after
sphaleron effects are included. The $U(1)_X$ group not only helps to stabilize
the dark matter but also helps in the elimination of the symmetric part of the
dark matter via $\chi-\bar{\chi}$ annihilation. For dark matter mass near the
proton mass, it explains why the baryon and dark matter abundances are of
similar magnitude (the baryon-dark-matter coincidence problem). This model is
testable in low threshold (sub-keV) direct dark matter search experiments.
| [
{
"created": "Thu, 4 May 2017 15:00:34 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Aug 2017 14:37:32 GMT",
"version": "v2"
}
] | 2017-09-20 | [
[
"Gu",
"Pei-Hong",
""
],
[
"Mohapatra",
"Rabindra N.",
""
]
] | We attempt to understand the baryon-dark-matter coincidence problem within the quark seesaw extension of the standard model where parity invariance is used to solve the strong CP problem. The $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ gauge symmetry of this model is extended by a dark $U(1)_X$ group plus inclusion of a heavy neutral vector-like fermion $\chi_{L,R}$ charged under the dark group which plays the role of dark matter. All fermions are Dirac type in this model. Decay of heavy scalars charged under $U(1)_X$ leads to simultaneous asymmetry generation of the dark matter and baryons after sphaleron effects are included. The $U(1)_X$ group not only helps to stabilize the dark matter but also helps in the elimination of the symmetric part of the dark matter via $\chi-\bar{\chi}$ annihilation. For dark matter mass near the proton mass, it explains why the baryon and dark matter abundances are of similar magnitude (the baryon-dark-matter coincidence problem). This model is testable in low threshold (sub-keV) direct dark matter search experiments. |
hep-ph/9602418 | Thorsten Kleinwort | T. Kleinwort and G. Kramer | Inclusive One- and Two-Jet Cross sections in $\gamma\gamma$ Reactions at
$e^+e^-$ Colliders | 25 pages, latex, 15 figures appended as uuencoded file | Nucl.Phys. B477 (1996) 3-26 | 10.1016/0550-3213(96)00363-X | DESY 96-035 | hep-ph | null | We have calculated inclusive one-- and two--jet production in photon--photon
collisions superimposing direct, single resolved and double resolved cross
sections for center of mass energies of the LEP1, LEP2 and NLC range. The
direct and single resolved cross sections are calculated up to
next--to--leading order. The double resolved two--jet cross section is
calculated only in LO with a $k$ factor estimated from the NLO one--jet cross
section. Various differential cross sections as functions of transverse momenta
and rapidities of the jets are evaluated.
| [
{
"created": "Wed, 28 Feb 1996 15:40:53 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Kleinwort",
"T.",
""
],
[
"Kramer",
"G.",
""
]
] | We have calculated inclusive one-- and two--jet production in photon--photon collisions superimposing direct, single resolved and double resolved cross sections for center of mass energies of the LEP1, LEP2 and NLC range. The direct and single resolved cross sections are calculated up to next--to--leading order. The double resolved two--jet cross section is calculated only in LO with a $k$ factor estimated from the NLO one--jet cross section. Various differential cross sections as functions of transverse momenta and rapidities of the jets are evaluated. |
hep-ph/9508245 | Aneesh Manohar | Aneesh V. Manohar | Effective Field Theories | Lectures on Effective Field Theories at the Lake Louise Winter
Institute, February 1995. 42 pages, 16 figures; extended version in
hep-ph/9606222 | null | null | UCSD/PTH 95-07 | hep-ph | null | These lectures introduce some of the basic notions of effective field
theories, as used in particle physics. The topics discussed are the $\Delta
S=1$ and $\Delta S =2$ weak interactions, and chiral perturbation theory as
applied to mesons, baryons, and hadrons containing heavy quarks.
| [
{
"created": "Sat, 5 Aug 1995 22:54:06 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Manohar",
"Aneesh V.",
""
]
] | These lectures introduce some of the basic notions of effective field theories, as used in particle physics. The topics discussed are the $\Delta S=1$ and $\Delta S =2$ weak interactions, and chiral perturbation theory as applied to mesons, baryons, and hadrons containing heavy quarks. |
1007.4015 | Enrico Lunghi | Enrico Lunghi and Amarjit Soni | An improved observable for the forward-backward asymmetry in B -> K* l+
l- and Bs -> phi l+ l- | 19 pages, 7 figures | JHEP 1011:121,2010 | 10.1007/JHEP11(2010)121 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the decay B -> K* l+ l- in the QCD factorization approach and
propose a new integrated observable whose dependence on the form factors is
almost negligible, consequently the non--perturbative error is significantly
reduced and indeed its overall theoretical error is dominated by perturbative
scale uncertainties. The new observable we propose is the ratio between the
integrated forward--backward asymmetry in the [4,6] GeV^2 and [1,4] GeV^2
dilepton invariant mass bins. This new observable is particularly interesting
because, when compared to the location of the zero of the FBA spectrum, it is
experimentally easier to measure and its theoretical uncertainties are almost
as small; moreover it displays a very strong dependence on the phase of the
Wilson coefficient C_10 that is otherwise only accessible through complicated
CP violating asymmetries. We illustrate the new physics sensitivity of this
observable within the context of few extensions of the Standard Model, namely
the SM with four generations, an MSSM with non--vanishing source of flavor
changing neutral currents in the down squark sector and a Z' model with tree
level flavor changing couplings.
| [
{
"created": "Thu, 22 Jul 2010 21:48:15 GMT",
"version": "v1"
}
] | 2010-11-30 | [
[
"Lunghi",
"Enrico",
""
],
[
"Soni",
"Amarjit",
""
]
] | We study the decay B -> K* l+ l- in the QCD factorization approach and propose a new integrated observable whose dependence on the form factors is almost negligible, consequently the non--perturbative error is significantly reduced and indeed its overall theoretical error is dominated by perturbative scale uncertainties. The new observable we propose is the ratio between the integrated forward--backward asymmetry in the [4,6] GeV^2 and [1,4] GeV^2 dilepton invariant mass bins. This new observable is particularly interesting because, when compared to the location of the zero of the FBA spectrum, it is experimentally easier to measure and its theoretical uncertainties are almost as small; moreover it displays a very strong dependence on the phase of the Wilson coefficient C_10 that is otherwise only accessible through complicated CP violating asymmetries. We illustrate the new physics sensitivity of this observable within the context of few extensions of the Standard Model, namely the SM with four generations, an MSSM with non--vanishing source of flavor changing neutral currents in the down squark sector and a Z' model with tree level flavor changing couplings. |
1009.3838 | Maria Valentina Carlucci | Maria Valentina Carlucci | Two-Higgs-doublet models with Minimal Flavour Violation | 6 pages, 1 figure, Proceedings of "QCD@Work 2010" - June 20-23, 2010
- Martina Franca (Italy) | AIP Conf.Proc.1317:292-297,2011 | 10.1063/1.3536573 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The tree-level flavour-changing neutral currents in the two-Higgs-doublet
models can be suppressed by protecting the breaking of either flavour or
flavour-blind symmetries, but only the first choice, implemented by the
application of the Minimal Flavour Violation hypothesis, is stable under
quantum corrections. Moreover, a two-Higgs-doublet model with Minimal Flavour
Violation enriched with flavour-blind phases can explain the anomalies recently
found in the Delta F = 2 transitions, namely the large CP-violating phase in
B_s mixing and the tension between epsilon_K and S_\psi_K.
| [
{
"created": "Mon, 20 Sep 2010 14:44:57 GMT",
"version": "v1"
}
] | 2011-02-01 | [
[
"Carlucci",
"Maria Valentina",
""
]
] | The tree-level flavour-changing neutral currents in the two-Higgs-doublet models can be suppressed by protecting the breaking of either flavour or flavour-blind symmetries, but only the first choice, implemented by the application of the Minimal Flavour Violation hypothesis, is stable under quantum corrections. Moreover, a two-Higgs-doublet model with Minimal Flavour Violation enriched with flavour-blind phases can explain the anomalies recently found in the Delta F = 2 transitions, namely the large CP-violating phase in B_s mixing and the tension between epsilon_K and S_\psi_K. |
2312.16587 | Suppanat Supanyo | Suppanat Supanyo, Chanon Hasuwannakit, Sikarin Yoo-Kong, Lunchakorn
Tannukij, Monsit Tanasittikosol | The natural smallness of Dirac neutrino mass from the multiplicative
Lagrangian | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an alternative scheme to provide an anomalous smallness of the
Dirac neutrino mass. The multiplicative Lagrangian model of the Higgs field
plays an essential role in explaining a huge difference between the mass of the
charged leptons and Dirac neutrinos while the ratio of Yukawa coupling between
these two groups of particles is naturally of order unity. On the other hand,
if the neutrino mass is mixed between the Dirac and Majorana types, the mass of
the right-handed neutrinos can be in the range between sub-eV and the grand
unification scale without fine-tuning and naturalness problems. Moreover, the
little hierarchy between the Yukawa coupling of top-quark and electron is also
discussed.
| [
{
"created": "Wed, 27 Dec 2023 14:25:09 GMT",
"version": "v1"
}
] | 2023-12-29 | [
[
"Supanyo",
"Suppanat",
""
],
[
"Hasuwannakit",
"Chanon",
""
],
[
"Yoo-Kong",
"Sikarin",
""
],
[
"Tannukij",
"Lunchakorn",
""
],
[
"Tanasittikosol",
"Monsit",
""
]
] | We present an alternative scheme to provide an anomalous smallness of the Dirac neutrino mass. The multiplicative Lagrangian model of the Higgs field plays an essential role in explaining a huge difference between the mass of the charged leptons and Dirac neutrinos while the ratio of Yukawa coupling between these two groups of particles is naturally of order unity. On the other hand, if the neutrino mass is mixed between the Dirac and Majorana types, the mass of the right-handed neutrinos can be in the range between sub-eV and the grand unification scale without fine-tuning and naturalness problems. Moreover, the little hierarchy between the Yukawa coupling of top-quark and electron is also discussed. |
hep-ph/9611437 | Jorge L. Lopez | J. Lopez, D. Nanopoulos, and A. Zichichi | Single-photon signals at LEP in supersymmetric models with a light
gravitino | 31 pages, LaTeX, 14 figures (included) | Phys.Rev.D55:5813-5825,1997 | 10.1103/PhysRevD.55.5813 | DOE/ER/40717-36, CTP-TAMU-58/96 | hep-ph | null | We study the single-photon signals expected at LEP in models with a very
light gravitino. The dominant process is neutralino-gravitino production (e+e-
-> chi+ G) with subsequent neutralino decay via chi->gamma+G, giving a
gamma+E_miss signal. We first calculate the cross section at arbitrary
center-of-mass energies and provide new analytic expressions for the
differential cross section valid for general neutralino compositions. We then
consider the constraints on the gravitino mass from LEP 1 and LEP161
single-photon searches, and possible such searches at the Tevatron. We show
that it is possible to evade the stringent LEP 1 limits and still obtain an
observable rate at LEP 2, in particular in the region of parameter space that
may explain the CDF e+e+gamma+gamma+E_T,miss event. As diphoton events from
neutralino pair-production would not be kinematically accessible in this
scenario, the observation of whichever photonic signal will discriminate among
the various light-gravitino scenarios in the literature. We also perform a
Monte Carlo simulation of the expected energy and angular distributions of the
emitted photon, and of the missing invariant mass expected in the events.
Finally we specialize the results to the case of a recently proposed
one-parameter no-scale supergravity model.
| [
{
"created": "Tue, 26 Nov 1996 19:30:23 GMT",
"version": "v1"
}
] | 2009-08-25 | [
[
"Lopez",
"J.",
""
],
[
"Nanopoulos",
"D.",
""
],
[
"Zichichi",
"A.",
""
]
] | We study the single-photon signals expected at LEP in models with a very light gravitino. The dominant process is neutralino-gravitino production (e+e- -> chi+ G) with subsequent neutralino decay via chi->gamma+G, giving a gamma+E_miss signal. We first calculate the cross section at arbitrary center-of-mass energies and provide new analytic expressions for the differential cross section valid for general neutralino compositions. We then consider the constraints on the gravitino mass from LEP 1 and LEP161 single-photon searches, and possible such searches at the Tevatron. We show that it is possible to evade the stringent LEP 1 limits and still obtain an observable rate at LEP 2, in particular in the region of parameter space that may explain the CDF e+e+gamma+gamma+E_T,miss event. As diphoton events from neutralino pair-production would not be kinematically accessible in this scenario, the observation of whichever photonic signal will discriminate among the various light-gravitino scenarios in the literature. We also perform a Monte Carlo simulation of the expected energy and angular distributions of the emitted photon, and of the missing invariant mass expected in the events. Finally we specialize the results to the case of a recently proposed one-parameter no-scale supergravity model. |
2212.12197 | Simone Rodini | Adam Freese, Andreas Metz, Barbara Pasquini, Simone Rodini | The gravitational form factors of the electron in quantum
electrodynamics | 8 pages, 1 figure | null | 10.1016/j.physletb.2023.137768 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the gravitational form factors of the electron at one loop in
quantum electrodynamics, decomposing these into contributions from the electron
and photon parts of the energy-momentum tensor. Ultraviolet divergences are
removed through renormalization in the $\overline{\text{MS}}$ scheme. Infrared
divergences are isolated and results are given in both dimensional
regularization and photon-mass regularization. The form factors contain
information about the electron's energy and angular momentum structure in QED,
as well as its mass radius. Whenever possible, we compare our results with the
existing literature.
| [
{
"created": "Fri, 23 Dec 2022 08:27:49 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Feb 2023 07:41:11 GMT",
"version": "v2"
}
] | 2023-02-20 | [
[
"Freese",
"Adam",
""
],
[
"Metz",
"Andreas",
""
],
[
"Pasquini",
"Barbara",
""
],
[
"Rodini",
"Simone",
""
]
] | We calculate the gravitational form factors of the electron at one loop in quantum electrodynamics, decomposing these into contributions from the electron and photon parts of the energy-momentum tensor. Ultraviolet divergences are removed through renormalization in the $\overline{\text{MS}}$ scheme. Infrared divergences are isolated and results are given in both dimensional regularization and photon-mass regularization. The form factors contain information about the electron's energy and angular momentum structure in QED, as well as its mass radius. Whenever possible, we compare our results with the existing literature. |
hep-ph/0207356 | Gudrun Hiller | Gudrun Hiller (SLAC) | First hint of non-standard CP violation from B --> Phi K_S decay | references added and minor text changes; conclusions unchanged; PRD
version; 5 pages, 2 figures, uses espcrc2.sty | Phys.Rev. D66 (2002) 071502 | 10.1103/PhysRevD.66.071502 | SLAC-PUB-9326 | hep-ph | null | We comment on the implications of the recently measured CP asymmetry in B -->
Phi K_S decay. The data disfavor the Standard Model at 2.7 sigma and -if the
trend persists in the future with higher statistics - require the existence of
CP violation beyond that in the CKM matrix. In particular, the b --> s bar{s} s
decay amplitude would require new contributions of comparable size to the
Standard Model ones with an order one phase. While not every model can deliver
such a large amount of CP and flavor violation, those with substantial FCNC
couplings to the Z can reproduce the experimental findings.
| [
{
"created": "Tue, 30 Jul 2002 19:50:55 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Aug 2002 19:09:06 GMT",
"version": "v2"
},
{
"created": "Thu, 10 Oct 2002 12:56:44 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Hiller",
"Gudrun",
"",
"SLAC"
]
] | We comment on the implications of the recently measured CP asymmetry in B --> Phi K_S decay. The data disfavor the Standard Model at 2.7 sigma and -if the trend persists in the future with higher statistics - require the existence of CP violation beyond that in the CKM matrix. In particular, the b --> s bar{s} s decay amplitude would require new contributions of comparable size to the Standard Model ones with an order one phase. While not every model can deliver such a large amount of CP and flavor violation, those with substantial FCNC couplings to the Z can reproduce the experimental findings. |
1309.2063 | Xuyang Liu | X. Y. Liu, K. Khosonthongkee, A. Limphirat and Y. Yan | Study of baryon octet electromagnetic form factors in perturbative
chiral quark model | 12 pages, 7 figures | J. Phys. G: Nucl. Part. Phys. 41, 055008 (2014) | 10.1088/0954-3899/41/5/055008 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The electromagnetic properties of baryon octet are studied in the
perturbative chiral quark model (PCQM). The relativistic quark wave function is
extracted by fitting the theoretical results of the proton charge form factor
to experimental data and the predetermined quark wave function is applied to
study the electromagnetic form factors of other octet baryons as well as
magnetic moments, charge and magnetic radii. The PCQM results are found, based
on the predetermined quark wave function, in good agreement with experimental
data.
| [
{
"created": "Mon, 9 Sep 2013 08:01:02 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Sep 2013 08:26:06 GMT",
"version": "v2"
},
{
"created": "Thu, 20 Mar 2014 07:17:39 GMT",
"version": "v3"
}
] | 2014-03-26 | [
[
"Liu",
"X. Y.",
""
],
[
"Khosonthongkee",
"K.",
""
],
[
"Limphirat",
"A.",
""
],
[
"Yan",
"Y.",
""
]
] | The electromagnetic properties of baryon octet are studied in the perturbative chiral quark model (PCQM). The relativistic quark wave function is extracted by fitting the theoretical results of the proton charge form factor to experimental data and the predetermined quark wave function is applied to study the electromagnetic form factors of other octet baryons as well as magnetic moments, charge and magnetic radii. The PCQM results are found, based on the predetermined quark wave function, in good agreement with experimental data. |
2209.03566 | Roman Nikolaevich Lee | P.A. Krachkov, R.N. Lee, A.I. Milstein | Photoproduction of $e^+e^-$ pair in a Coulomb field near the threshold | null | null | 10.1016/j.physletb.2022.137498 | null | hep-ph physics.atom-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the electron-positron pair production by a photon in Coulomb
field near threshold. We obtain the analytical results for the particle energy
spectrum and angular distribution exactly in the parameter $Ze^2/\hbar v$. We
show that Furry-Sommerfeld-Maue approximation for the wave functions used by
Nishina, Tomonaga and Sakata is not sufficient and leads to wrong results.
| [
{
"created": "Thu, 8 Sep 2022 05:13:25 GMT",
"version": "v1"
}
] | 2022-10-19 | [
[
"Krachkov",
"P. A.",
""
],
[
"Lee",
"R. N.",
""
],
[
"Milstein",
"A. I.",
""
]
] | We consider the electron-positron pair production by a photon in Coulomb field near threshold. We obtain the analytical results for the particle energy spectrum and angular distribution exactly in the parameter $Ze^2/\hbar v$. We show that Furry-Sommerfeld-Maue approximation for the wave functions used by Nishina, Tomonaga and Sakata is not sufficient and leads to wrong results. |
hep-ph/0011098 | Thomas E. Coan | T. E. Coan | Radiative B Decays at CLEO | Presented at the XXXth International Conference on High Energy
Physics, (ICHEP2000), July-August 2000, Osaka, Japan; 3 pages, 4 figures | null | null | SMU-HEP-00-13 | hep-ph | null | We report on the status of a variety of radiative B decays studied by the
CLEO detector with $9.7\times 10^6$ $B\bar{B}$ pairs.
| [
{
"created": "Tue, 7 Nov 2000 20:35:19 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Coan",
"T. E.",
""
]
] | We report on the status of a variety of radiative B decays studied by the CLEO detector with $9.7\times 10^6$ $B\bar{B}$ pairs. |
1612.08168 | Juri Fiaschi | Elena Accomando, Juri Fiaschi, Francesco Hautmann, Stefano Moretti,
Claire H. Shepherd-Themistocleous | The effect of real and virtual photons in the di-lepton channel at the
LHC | 9 pages, 5 figures | null | 10.1016/j.physletb.2017.04.025 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a study of di-lepton production at the CERN Large Hadron Collider
with a particular focus on the contribution resulting from both real and
virtual photons in the initial state. We discuss the region of phase space in
which the invariant mass of the lepton pair is of the order of several TeV,
where searches for new physics phenomena yielding a di-lepton signature are
presently carried out. We study both the yield and associated uncertainties for
all possible topologies in photon-induced di-lepton production and compare
these with what is expected in the standard Drell-Yan channel, where
quark-antiquark pairs are responsible for the production of lepton pairs. We
analyse the impact of these QED contributions on the expected Standard Model
background and on searches for new physics. In this latter case, we use the
production of an extra heavy $Z^\prime$-boson predicted by the Sequential
Standard Model (SSM) as a benchmark process.
| [
{
"created": "Sat, 24 Dec 2016 11:33:12 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Apr 2017 14:09:59 GMT",
"version": "v2"
}
] | 2017-04-19 | [
[
"Accomando",
"Elena",
""
],
[
"Fiaschi",
"Juri",
""
],
[
"Hautmann",
"Francesco",
""
],
[
"Moretti",
"Stefano",
""
],
[
"Shepherd-Themistocleous",
"Claire H.",
""
]
] | We present a study of di-lepton production at the CERN Large Hadron Collider with a particular focus on the contribution resulting from both real and virtual photons in the initial state. We discuss the region of phase space in which the invariant mass of the lepton pair is of the order of several TeV, where searches for new physics phenomena yielding a di-lepton signature are presently carried out. We study both the yield and associated uncertainties for all possible topologies in photon-induced di-lepton production and compare these with what is expected in the standard Drell-Yan channel, where quark-antiquark pairs are responsible for the production of lepton pairs. We analyse the impact of these QED contributions on the expected Standard Model background and on searches for new physics. In this latter case, we use the production of an extra heavy $Z^\prime$-boson predicted by the Sequential Standard Model (SSM) as a benchmark process. |
2107.04716 | Carlos Alvarado | Carlos Alvarado, Alfredo Aranda, and Cesar Bonilla | Sub-GeV $U(1)_{R}$ gauge boson to address the proton radius discrepancy | 14 pages, 6 figures, 2 tables. v2: typos corrected, references added.
Matches published version in PRD | Phys.Rev.D 104 (2021) 11, 115019 | 10.1103/PhysRevD.104.115019 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a Standard Model extension by a $U(1)_{R}$ gauge symmetry where
only right-handed chiral fermions can carry a non-trivial charge. Here we show
that the simplest anomaly-free solution to accommodate the proton charge radius
discrepancy takes right-handed muons $\mu_R$ and first generation quarks, $u_R$
and $d_R$. Consistency with the latest muon's $(g-2)$ measurements is achieved
through an extra light scalar, which itself must lie in the tens of MeV mass
range to be viable.
| [
{
"created": "Fri, 9 Jul 2021 23:18:05 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Dec 2021 02:42:07 GMT",
"version": "v2"
}
] | 2021-12-30 | [
[
"Alvarado",
"Carlos",
""
],
[
"Aranda",
"Alfredo",
""
],
[
"Bonilla",
"Cesar",
""
]
] | We propose a Standard Model extension by a $U(1)_{R}$ gauge symmetry where only right-handed chiral fermions can carry a non-trivial charge. Here we show that the simplest anomaly-free solution to accommodate the proton charge radius discrepancy takes right-handed muons $\mu_R$ and first generation quarks, $u_R$ and $d_R$. Consistency with the latest muon's $(g-2)$ measurements is achieved through an extra light scalar, which itself must lie in the tens of MeV mass range to be viable. |
1609.08127 | Alexander Helmboldt | Alexander J. Helmboldt and Manfred Lindner | Prospects for three-body Higgs boson decays into extra light scalars | 14 pages, 6 figures, 6 tables. Minor modifications, slightly enlarged
discussion of results, few references added, version published in PRD | Phys. Rev. D 95, 055008 (2017) | 10.1103/PhysRevD.95.055008 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Within models containing a very light scalar particle coupled to the 125 GeV
Higgs boson, we present the first detailed study of Higgs decays into three of
these light scalars. We determine model-independent conditions which the scalar
sector after electroweak symmetry breaking has to satisfy in order for the
three-body channel to become relevant. Using a specific model -- the real
scalar singlet-extension of the Standard Model (SM) -- we then identify
scenarios, where the rates of scalar three-body Higgs decays are comparable to
or even exceed those of the well-studied two-body channel. All those scenarios
are shown to be compatible with current experimental and theoretical
constraints. We finally argue that scalar three-body Higgs decays lead to
exciting new collider signatures with six SM fermions in the final state.
Calculating the corresponding event rates, we find that e.g. six-muon or
six-tau final states may be in reach of dedicated searches at the LHC or ILC
experiments.
| [
{
"created": "Mon, 26 Sep 2016 19:19:48 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Mar 2017 10:47:42 GMT",
"version": "v2"
}
] | 2017-03-20 | [
[
"Helmboldt",
"Alexander J.",
""
],
[
"Lindner",
"Manfred",
""
]
] | Within models containing a very light scalar particle coupled to the 125 GeV Higgs boson, we present the first detailed study of Higgs decays into three of these light scalars. We determine model-independent conditions which the scalar sector after electroweak symmetry breaking has to satisfy in order for the three-body channel to become relevant. Using a specific model -- the real scalar singlet-extension of the Standard Model (SM) -- we then identify scenarios, where the rates of scalar three-body Higgs decays are comparable to or even exceed those of the well-studied two-body channel. All those scenarios are shown to be compatible with current experimental and theoretical constraints. We finally argue that scalar three-body Higgs decays lead to exciting new collider signatures with six SM fermions in the final state. Calculating the corresponding event rates, we find that e.g. six-muon or six-tau final states may be in reach of dedicated searches at the LHC or ILC experiments. |
hep-ph/9709326 | Hegyi Sandor | S. Hegyi (KFKI Rmki) | Asymptotic multiplicity scaling: a renormalization group perspective | 13 pages REVTeX | null | null | null | hep-ph | null | A generalization of the Polyakov-Koba-Nielsen-Olesen scaling law of the
multiplicity distributions P(n,s) is developed. It states that a suitable
change in the normalization point of P(n,s) compensated by a rescaling can
restore data collapsing onto a universal curve if the original scaling rule is
violated. We show that the iteratively executed transformation of P(n,s) can be
viewed as varying the collision energy. The e+e- and p-pbar multiplicity data
at top energies are found to exhibit a fixed point property of the iteration.
| [
{
"created": "Fri, 12 Sep 1997 12:00:27 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Hegyi",
"S.",
"",
"KFKI Rmki"
]
] | A generalization of the Polyakov-Koba-Nielsen-Olesen scaling law of the multiplicity distributions P(n,s) is developed. It states that a suitable change in the normalization point of P(n,s) compensated by a rescaling can restore data collapsing onto a universal curve if the original scaling rule is violated. We show that the iteratively executed transformation of P(n,s) can be viewed as varying the collision energy. The e+e- and p-pbar multiplicity data at top energies are found to exhibit a fixed point property of the iteration. |
1212.3694 | Subrata Khan | Subrata Khan, Srubabati Goswami, Sourov Roy | Vacuum Stability Constraints on the Minimal Singlet TeV Seesaw Model | One loop effective potential due to heavy neutrino included, 20
pages, 9 figures | Phys. Rev. D 89, 073021 (2014) | 10.1103/PhysRevD.89.073021 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the minimal seesaw model in which two gauge singlet right handed
neutrinos with opposite lepton numbers are added to the Standard Model. In this
model, the smallness of the neutrino mass is explained by the tiny lepton
number violating coupling between one of the singlets with the standard
left-handed neutrinos. This allows one to have the right handed neutrino mass
at the TeV scale as well as appreciable mixing between the light and heavy
states. This model is fully reconstructible in terms of the neutrino
oscillation parameters apart from the overall coupling strengths. We show that
the overall coupling strength $y_\nu$ for the Dirac type coupling between the
left handed neutrino and one of the singlets can be restricted by consideration
of the (meta)stability bounds on the electroweak vacuum. In this scenario the
lepton flavor violating decays of charged leptons can be appreciable which can
put further constraint on $y_\nu$, for right-handed neutrinos at TeV scale. We
discuss the combined constraints on $y_\nu$ for this scenario from the process
$\mu \rightarrow e \gamma$ and from the consideration of vacuum (meta)stability
constraints on the Higgs self coupling. We also briefly discuss the
implications for neutrinoless double beta decay and possible signatures of the
model that can be expected at colliders.
| [
{
"created": "Sat, 15 Dec 2012 15:40:13 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Nov 2013 05:59:35 GMT",
"version": "v2"
},
{
"created": "Tue, 8 Apr 2014 16:08:33 GMT",
"version": "v3"
}
] | 2014-05-07 | [
[
"Khan",
"Subrata",
""
],
[
"Goswami",
"Srubabati",
""
],
[
"Roy",
"Sourov",
""
]
] | We consider the minimal seesaw model in which two gauge singlet right handed neutrinos with opposite lepton numbers are added to the Standard Model. In this model, the smallness of the neutrino mass is explained by the tiny lepton number violating coupling between one of the singlets with the standard left-handed neutrinos. This allows one to have the right handed neutrino mass at the TeV scale as well as appreciable mixing between the light and heavy states. This model is fully reconstructible in terms of the neutrino oscillation parameters apart from the overall coupling strengths. We show that the overall coupling strength $y_\nu$ for the Dirac type coupling between the left handed neutrino and one of the singlets can be restricted by consideration of the (meta)stability bounds on the electroweak vacuum. In this scenario the lepton flavor violating decays of charged leptons can be appreciable which can put further constraint on $y_\nu$, for right-handed neutrinos at TeV scale. We discuss the combined constraints on $y_\nu$ for this scenario from the process $\mu \rightarrow e \gamma$ and from the consideration of vacuum (meta)stability constraints on the Higgs self coupling. We also briefly discuss the implications for neutrinoless double beta decay and possible signatures of the model that can be expected at colliders. |
2211.01387 | Timothy Hobbs | Marco Guzzi, T. J. Hobbs, Keping Xie, Joey Huston, Pavel Nadolsky,
C.-P. Yuan | The persistent nonperturbative charm enigma | 10 pages, 2 figures in main Letter; includes 6 pages of Supplementary
Discussion with 6 additional figures; updated following publication in PLB
843 (2023) 137975 | Phys. Lett. B 843 (2023) 137975 | 10.1016/j.physletb.2023.137975 | ANL-179603, FERMILAB-PUB-22-786-T, MSUHEP-22-035, SMU-HEP-22-10 | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | The question of the existence and possible magnitude of nonperturbative
(often called "intrinsic") charm in the proton has long confounded attempts to
cleanly isolate such a contribution in global analyses of high-energy
experiments. In this letter, we show that the available (non)perturbative QCD
theory and hadronic data have still not developed to a sufficient level to
clearly resolve this problem. We highlight a number of challenging aspects that
must be confronted in extracting nonperturbative charm in PDF fits, and in so
doing, present an updated next-to-next-to-leading order CT analysis of fitted
charm, CT18 FC, which we also compare to recent studies. We outline the theory
developments and future data needed to make progress on this subject.
| [
{
"created": "Wed, 2 Nov 2022 18:00:02 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Nov 2022 01:53:05 GMT",
"version": "v2"
},
{
"created": "Wed, 21 Jun 2023 03:54:43 GMT",
"version": "v3"
}
] | 2023-06-22 | [
[
"Guzzi",
"Marco",
""
],
[
"Hobbs",
"T. J.",
""
],
[
"Xie",
"Keping",
""
],
[
"Huston",
"Joey",
""
],
[
"Nadolsky",
"Pavel",
""
],
[
"Yuan",
"C. -P.",
""
]
] | The question of the existence and possible magnitude of nonperturbative (often called "intrinsic") charm in the proton has long confounded attempts to cleanly isolate such a contribution in global analyses of high-energy experiments. In this letter, we show that the available (non)perturbative QCD theory and hadronic data have still not developed to a sufficient level to clearly resolve this problem. We highlight a number of challenging aspects that must be confronted in extracting nonperturbative charm in PDF fits, and in so doing, present an updated next-to-next-to-leading order CT analysis of fitted charm, CT18 FC, which we also compare to recent studies. We outline the theory developments and future data needed to make progress on this subject. |
1401.4017 | Marco Cirelli | Marco Cirelli, Nicolao Fornengo, Marco Taoso, Andrea Vittino | Anti-helium from Dark Matter annihilations | 13 pages, 5 figures. In v2 an appendix is added with the computation
of the astrophysical anti-helium background (several other small
clarifications are added). v2 matches version published on JHEP. In v3 we
correct a bug in the computation of the astrophysical anti-helium background
and take the occasion to add some discussion and comments. The main results
are not affected | JHEP 1408 (2014) 009 | 10.1007/JHEP08(2014)009 | SACLAY-T14/003 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Galactic Dark Matter (DM) annihilations can produce cosmic-ray anti-nuclei
via the nuclear coalescence of the anti-protons and anti-neutrons originated
directly from the annihilation process. Since anti-deuterons have been shown to
offer a distinctive DM signal, with potentially good prospects of detection in
large portions of the DM-particle parameter space, we explore here the
production of heavier anti-nuclei, specifically anti-helium. Even more than for
anti-deuterons, the DM-produced anti-He flux can be mostly prominent over the
astrophysical anti-He background at low kinetic energies, typically below 3-5
GeV/n. However, the larger number of anti-nucleons involved in the formation
process makes the anti-He flux extremely small. We therefore explore, for a few
DM benchmark cases, whether the yield is sufficient to allow for anti-He
detection in current-generation experiments, such as AMS-02. We account for the
uncertainties due to the propagation in the Galaxy and to the uncertain details
of the coalescence process, and we consider the constraints already imposed by
anti-proton searches. We find that only for very optimistic configurations it
might be possible to achieve detection with current generation detectors. We
estimate that, in more realistic configurations, an increase in experimental
sensitivity at low-kinetic energies of about a factor of 500-1000 would allow
to start probing DM through the rare cosmic anti-He production.
| [
{
"created": "Thu, 16 Jan 2014 13:20:33 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Oct 2014 14:26:11 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Aug 2016 12:33:02 GMT",
"version": "v3"
}
] | 2016-08-25 | [
[
"Cirelli",
"Marco",
""
],
[
"Fornengo",
"Nicolao",
""
],
[
"Taoso",
"Marco",
""
],
[
"Vittino",
"Andrea",
""
]
] | Galactic Dark Matter (DM) annihilations can produce cosmic-ray anti-nuclei via the nuclear coalescence of the anti-protons and anti-neutrons originated directly from the annihilation process. Since anti-deuterons have been shown to offer a distinctive DM signal, with potentially good prospects of detection in large portions of the DM-particle parameter space, we explore here the production of heavier anti-nuclei, specifically anti-helium. Even more than for anti-deuterons, the DM-produced anti-He flux can be mostly prominent over the astrophysical anti-He background at low kinetic energies, typically below 3-5 GeV/n. However, the larger number of anti-nucleons involved in the formation process makes the anti-He flux extremely small. We therefore explore, for a few DM benchmark cases, whether the yield is sufficient to allow for anti-He detection in current-generation experiments, such as AMS-02. We account for the uncertainties due to the propagation in the Galaxy and to the uncertain details of the coalescence process, and we consider the constraints already imposed by anti-proton searches. We find that only for very optimistic configurations it might be possible to achieve detection with current generation detectors. We estimate that, in more realistic configurations, an increase in experimental sensitivity at low-kinetic energies of about a factor of 500-1000 would allow to start probing DM through the rare cosmic anti-He production. |
0707.3661 | Alfredo Aranda | Alfredo Aranda (Colima U.) | Neutrino mixing from the double tetrahedral group T^{\prime} | 4 pages, no figures. References added and minor typos corrected.
Version to appear in PRD | Phys.Rev.D76:111301,2007 | 10.1103/PhysRevD.76.111301 | DCP -07-01 | hep-ph | null | It is shown that it is possible to create successful models of flavor for
both quarks and leptons using the discrete non-abelian group $T^{\prime}$ by
itself. Two simple realizations are presented that can be used as the starting
point for more general scenarios. In addition to the Minimal Supersymmetric
Standard Model particle content, the models include three generations of right
handed neutrinos and four scalar flavon fields. Three of the flavons are needed
in the quark and charged lepton sector of the models and the fourth flavon
participates only in the neutrino sector.
| [
{
"created": "Wed, 25 Jul 2007 03:13:34 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Nov 2007 22:42:01 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Aranda",
"Alfredo",
"",
"Colima U."
]
] | It is shown that it is possible to create successful models of flavor for both quarks and leptons using the discrete non-abelian group $T^{\prime}$ by itself. Two simple realizations are presented that can be used as the starting point for more general scenarios. In addition to the Minimal Supersymmetric Standard Model particle content, the models include three generations of right handed neutrinos and four scalar flavon fields. Three of the flavons are needed in the quark and charged lepton sector of the models and the fourth flavon participates only in the neutrino sector. |
0802.0934 | David Bugg | D.V. Bugg (Queen Mary, University of London, UK) | How Resonances can synchronise with Thresholds | 19 pages, 6 figures. Replaces 0709.1254 | J.Phys.G35:075005,2008 | 10.1088/0954-3899/35/7/075005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The mechanism by which a threshold may capture a resonance is examined. It
involves a threshold cusp interfering constructively with either or both (i) a
resonance produced via confinement, (ii) attractive t- and u-channel exchanges.
The fo(980), X(3872) and Z(4430) are studied in detail. The fo(980) provides a
valuable model of the locking mechanism. The X(3872) is too narrow to be fitted
by a cusp, and requires either a resonance or virtual state. The Z(4430) can be
fitted as a resonance but also can be fitted successfully by a cusp with no
nearby resonant pole.
| [
{
"created": "Thu, 7 Feb 2008 09:52:37 GMT",
"version": "v1"
},
{
"created": "Sun, 17 Feb 2008 15:12:08 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Bugg",
"D. V.",
"",
"Queen Mary, University of London, UK"
]
] | The mechanism by which a threshold may capture a resonance is examined. It involves a threshold cusp interfering constructively with either or both (i) a resonance produced via confinement, (ii) attractive t- and u-channel exchanges. The fo(980), X(3872) and Z(4430) are studied in detail. The fo(980) provides a valuable model of the locking mechanism. The X(3872) is too narrow to be fitted by a cusp, and requires either a resonance or virtual state. The Z(4430) can be fitted as a resonance but also can be fitted successfully by a cusp with no nearby resonant pole. |
1004.2350 | Vitaly Vorobiev | Alex Bondar, Anton Poluektov, Vitaly Vorobiev | Charm mixing in the model-independent analysis of correlated D0-D0bar
decays | 10 pages, 2 figures | Phys.Rev.D82:034033,2010 | 10.1103/PhysRevD.82.034033 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the impact of charm mixing on the model-independent gamma
measurement using Dalitz plot analysis of the three-body D decay from B+->DK+
process, and show that ignoring the mixing at all stages of the analysis is
safe up to a sub-degree level of precision. We also find that in the coherent
production of D0-D0* system in e+e- collisions, the effect of charm mixing is
enhanced, and propose a model-independent method to measure charm mixing
parameters in the time-integrated Dalitz analysis at charm factories.
| [
{
"created": "Wed, 14 Apr 2010 08:29:27 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Jun 2010 06:53:25 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Bondar",
"Alex",
""
],
[
"Poluektov",
"Anton",
""
],
[
"Vorobiev",
"Vitaly",
""
]
] | We investigate the impact of charm mixing on the model-independent gamma measurement using Dalitz plot analysis of the three-body D decay from B+->DK+ process, and show that ignoring the mixing at all stages of the analysis is safe up to a sub-degree level of precision. We also find that in the coherent production of D0-D0* system in e+e- collisions, the effect of charm mixing is enhanced, and propose a model-independent method to measure charm mixing parameters in the time-integrated Dalitz analysis at charm factories. |
1607.08349 | Sandra Klevansky | S.P. Klevansky, R.H. Lemmer, and Alireza Beygi | Amplitude determination for $M M \to M M$, $M = \pi, K$ and
cross-sections for $\gamma \gamma \to \pi^+ \pi^-, \pi^0 \pi^0, \pi^0 \eta$
in a chiral model | 23 pages, 10 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Dai and Pennington have performed a comprehensive analysis of essentially all
pion and kaon pair production data from two-photon collisions below 1.5 GeV,
including all high statistics results from Belle, as well as the older data
from Mark II at SLAC, CELLO at DESY, and Crystal Ball at SLAC. Imposing the
basic constraints required by analyticity, unitarity, and crossing symmetry and
making use of Low's low-energy theorem for QED, they were able to extract the
final-state, strong-interaction scattering amplitudes for the intermediate $\pi
\pi \to \pi \pi$ and $\pi \pi \to K \overline{K}$ reactions in a
model-independent fashion. In addition, they provided good fits to the
respective $\gamma \gamma \to \pi \pi$ cross-sections that are known in the
low-energy sector in the restricted angular range, $| \cos \theta | < 0.6 -
0.8$. Using the parameters obtained in this fashion, these authors constructed
the $\gamma \gamma \to \pi \pi$ cross-sections integrated over the full angular
range. In the present work, we use a version of chiral perturbation theory
developed by Oller and Oset to evaluate the final-state, strong-interaction
amplitudes theoretically, and we compare our low-energy QCD-based results with
the amplitudes extracted by Dai and Pennington. We also calculate the $\gamma
\gamma \to \pi \pi$ cross-sections (integrated over the full angular range) and
compare them with those obtained by Dai and Pennington. These calculations give
a more detailed insight into the fit of chiral perturbation theory, not just to
the measured $\gamma \gamma \to \pi \pi$ cross-sections, as is usually
presented, but rather to a higher level of detail through the available
analysis of the experimental data for the underlying final-state,
strong-interaction, meson-meson scattering amplitudes $\pi \pi \to \pi \pi$ and
$\pi \pi \to K \overline{K}$ themselves. The fits appear to be sensible.
| [
{
"created": "Thu, 28 Jul 2016 08:27:38 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Mar 2024 10:33:23 GMT",
"version": "v2"
}
] | 2024-03-26 | [
[
"Klevansky",
"S. P.",
""
],
[
"Lemmer",
"R. H.",
""
],
[
"Beygi",
"Alireza",
""
]
] | Dai and Pennington have performed a comprehensive analysis of essentially all pion and kaon pair production data from two-photon collisions below 1.5 GeV, including all high statistics results from Belle, as well as the older data from Mark II at SLAC, CELLO at DESY, and Crystal Ball at SLAC. Imposing the basic constraints required by analyticity, unitarity, and crossing symmetry and making use of Low's low-energy theorem for QED, they were able to extract the final-state, strong-interaction scattering amplitudes for the intermediate $\pi \pi \to \pi \pi$ and $\pi \pi \to K \overline{K}$ reactions in a model-independent fashion. In addition, they provided good fits to the respective $\gamma \gamma \to \pi \pi$ cross-sections that are known in the low-energy sector in the restricted angular range, $| \cos \theta | < 0.6 - 0.8$. Using the parameters obtained in this fashion, these authors constructed the $\gamma \gamma \to \pi \pi$ cross-sections integrated over the full angular range. In the present work, we use a version of chiral perturbation theory developed by Oller and Oset to evaluate the final-state, strong-interaction amplitudes theoretically, and we compare our low-energy QCD-based results with the amplitudes extracted by Dai and Pennington. We also calculate the $\gamma \gamma \to \pi \pi$ cross-sections (integrated over the full angular range) and compare them with those obtained by Dai and Pennington. These calculations give a more detailed insight into the fit of chiral perturbation theory, not just to the measured $\gamma \gamma \to \pi \pi$ cross-sections, as is usually presented, but rather to a higher level of detail through the available analysis of the experimental data for the underlying final-state, strong-interaction, meson-meson scattering amplitudes $\pi \pi \to \pi \pi$ and $\pi \pi \to K \overline{K}$ themselves. The fits appear to be sensible. |
hep-ph/0203125 | Andrei Davydychev | A.I. Davydychev, K. Schilcher, H. Spiesberger | Hadronic corrections to the muon decay | LaTeX, 9 pages, 2 figures (in eps format), contribution to the
Proceedings of QFTHEP-2001 (Moscow, Russia, September 2001), a brief (but
updated) review of the results of hep-ph/0011221 | null | null | MZ-TH/01-40 | hep-ph | null | We consider the O(alpha^2) hadronic corrections to the energy spectrum of the
decay electron in muon decay. We find that the correction can be described,
within good approximation, by a linear function in the electron energy.
Explicit expressions for the form factors needed in an approach based on
dispersion integrals are given.
| [
{
"created": "Wed, 13 Mar 2002 19:41:26 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Davydychev",
"A. I.",
""
],
[
"Schilcher",
"K.",
""
],
[
"Spiesberger",
"H.",
""
]
] | We consider the O(alpha^2) hadronic corrections to the energy spectrum of the decay electron in muon decay. We find that the correction can be described, within good approximation, by a linear function in the electron energy. Explicit expressions for the form factors needed in an approach based on dispersion integrals are given. |
2209.03208 | Mattias Sj\"o | Benjamin Alvarez, Johan Bijnens and Mattias Sj\"o | NNLO Positivity Bounds on ChPT for a General Number of Flavours | In proceedings of the 10th International Workshop on Chiral Dynamics
- CD2021, 15-19 November 2021, Beijing (online). 10 pages, 5 figures | null | null | LU-TP 22-55 | hep-ph | http://creativecommons.org/licenses/by-nc-nd/4.0/ | We present positivity bounds, derived from the principles of analyticity,
unitarity and crossing symmetry, that constrain the low-energy constants of
chiral perturbation theory. Bounds are produced for 2, 3 or more flavours with
equal meson masses, up to and including next-to-next-to-leading order (NNLO),
using the second and higher derivatives of the amplitude. We enhance the bounds
by using the most general isospin combinations posible (or higher-flavour
counterparts thereof) and by analytically integrating the low-energy range of
the amplitude. In addition, we present a powerful and general mathematical
framework for efficiently managing large numbers of positivity bounds.
| [
{
"created": "Wed, 7 Sep 2022 15:10:45 GMT",
"version": "v1"
}
] | 2022-09-08 | [
[
"Alvarez",
"Benjamin",
""
],
[
"Bijnens",
"Johan",
""
],
[
"Sjö",
"Mattias",
""
]
] | We present positivity bounds, derived from the principles of analyticity, unitarity and crossing symmetry, that constrain the low-energy constants of chiral perturbation theory. Bounds are produced for 2, 3 or more flavours with equal meson masses, up to and including next-to-next-to-leading order (NNLO), using the second and higher derivatives of the amplitude. We enhance the bounds by using the most general isospin combinations posible (or higher-flavour counterparts thereof) and by analytically integrating the low-energy range of the amplitude. In addition, we present a powerful and general mathematical framework for efficiently managing large numbers of positivity bounds. |
2101.12135 | Jo\~ao Barata | Jo\~ao Barata, Fabio Dom\'inguez, Carlos Salgado, V\'ictor Vila | A modified in-medium evolution equation with color coherence | 23 pages, 3 figures; Updated text, same results | null | 10.1007/JHEP05(2021)148 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | QCD jets produced in heavy-ion collisions at LHC or RHIC energies partially
evolve inside the produced hot and dense quark gluon plasma, offering unique
opportunities to study QCD splitting processes in different backgrounds.
Induced (modified) splittings are expected to be the most relevant mechanism
driving the modifications of in-medium jets compared to vacuum jets for a wide
sets of observables. Although color coherence among different emitters has been
identified as an essential mechanism in studies of the {\it QCD antenna
radiation}, it is usually neglected in the multi-gluon medium-induced cascade.
This independent gluon emission approximation can be analytically proved to be
valid in the limit of very large media, but corrections or modifications to it
have not been computed before in the context of the evolution (or rate)
equation describing the gluon cascade. We propose a modified evolution equation
that includes corrections due to the interference of subsequent emitters. In
order to do so, we first compute a modified splitting kernel following the
usual procedure of factorizing it from the subsequent Brownian motion. The
calculation is performed in the two-gluon configuration with no overlapping
formation times, that is expected to provide the first correction to the
completely independent picture.
| [
{
"created": "Thu, 28 Jan 2021 17:27:55 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Apr 2021 12:49:02 GMT",
"version": "v2"
}
] | 2021-06-17 | [
[
"Barata",
"João",
""
],
[
"Domínguez",
"Fabio",
""
],
[
"Salgado",
"Carlos",
""
],
[
"Vila",
"Víctor",
""
]
] | QCD jets produced in heavy-ion collisions at LHC or RHIC energies partially evolve inside the produced hot and dense quark gluon plasma, offering unique opportunities to study QCD splitting processes in different backgrounds. Induced (modified) splittings are expected to be the most relevant mechanism driving the modifications of in-medium jets compared to vacuum jets for a wide sets of observables. Although color coherence among different emitters has been identified as an essential mechanism in studies of the {\it QCD antenna radiation}, it is usually neglected in the multi-gluon medium-induced cascade. This independent gluon emission approximation can be analytically proved to be valid in the limit of very large media, but corrections or modifications to it have not been computed before in the context of the evolution (or rate) equation describing the gluon cascade. We propose a modified evolution equation that includes corrections due to the interference of subsequent emitters. In order to do so, we first compute a modified splitting kernel following the usual procedure of factorizing it from the subsequent Brownian motion. The calculation is performed in the two-gluon configuration with no overlapping formation times, that is expected to provide the first correction to the completely independent picture. |
hep-ph/0402181 | Luis Lavoura | L. Lavoura | Extension of the Buchalla-Safir bound | 9 pages, 1 figure | Eur.Phys.J. C40 (2005) 187-191 | 10.1140/epjc/s2005-02142-0 | null | hep-ph | null | I provide a simple derivation of the Buchalla-Safir bound on gamma. I
generalize it to the case where an upper bound on the phase of the penguin
pollution is assumed. I apply the Buchalla-Safir bound, and its generalization,
to the recent Belle data on CP violation in B --> pi+ pi-.
| [
{
"created": "Wed, 18 Feb 2004 11:16:33 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Lavoura",
"L.",
""
]
] | I provide a simple derivation of the Buchalla-Safir bound on gamma. I generalize it to the case where an upper bound on the phase of the penguin pollution is assumed. I apply the Buchalla-Safir bound, and its generalization, to the recent Belle data on CP violation in B --> pi+ pi-. |
hep-ph/0206078 | Stefan Antusch | Stefan Antusch, Joern Kersten, Manfred Lindner, Michael Ratz | The LMA Solution from Bimaximal Lepton Mixing at the GUT Scale by
Renormalization Group Running | 14 pages, 10 figures; references and a subsection containing an
example with odd CP parities added; results and conclusions unchanged | Phys.Lett. B544 (2002) 1-10 | 10.1016/S0370-2693(02)02470-X | TUM-HEP-466/02 | hep-ph | null | We show that in see-saw models with bimaximal lepton mixing at the GUT scale
and with zero CP phases, the solar mixing angle theta_{12} generically evolves
towards sizably smaller values due to Renormalization Group effects, whereas
the evolution of theta_{13} and theta_{23} is comparatively small. The
currently favored LMA solution of the solar neutrino problem can thus be
obtained in a natural way from bimaximal mixing at the GUT scale. We present
numerical examples for the evolution of the leptonic mixing angles in the
Standard Model and the MSSM, in which the current best-fit values of the LMA
mixing angles are produced. These include a case where the mass eigenstates
corresponding to the solar mass squared difference have opposite CP parity.
| [
{
"created": "Fri, 7 Jun 2002 14:09:08 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Aug 2002 09:58:16 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Antusch",
"Stefan",
""
],
[
"Kersten",
"Joern",
""
],
[
"Lindner",
"Manfred",
""
],
[
"Ratz",
"Michael",
""
]
] | We show that in see-saw models with bimaximal lepton mixing at the GUT scale and with zero CP phases, the solar mixing angle theta_{12} generically evolves towards sizably smaller values due to Renormalization Group effects, whereas the evolution of theta_{13} and theta_{23} is comparatively small. The currently favored LMA solution of the solar neutrino problem can thus be obtained in a natural way from bimaximal mixing at the GUT scale. We present numerical examples for the evolution of the leptonic mixing angles in the Standard Model and the MSSM, in which the current best-fit values of the LMA mixing angles are produced. These include a case where the mass eigenstates corresponding to the solar mass squared difference have opposite CP parity. |
1101.2158 | George Wei-Shu Hou | George W.S. Hou | A brief (p)review on a possible fourth generation world to come | Talk given at 35th International Conference on High Energy Physics
(ICHEP2010), Paris, France, July 22-28, 2010 | PoS ICHEP2010:244,2010 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We pick up the thread of $B\to K\pi$ direct CPV (DCPV) difference, linking to
the 4th generation prediction (and current quest) of $t$-dependent CPV (TCPV)
in $B_s \to J/\psi\,\phi$. We then soar up to the heavens with possible source
of CPV for the Universe (CPV-4-U); for the "cauldron" that stirs strong phase
transitions, we raise the possible link between electroweak symmetry breaking
and large Yukawa couplings (4-EWSB). With the prognosis for 2011, 2012 and
beyond, we stress these as preview for the possible 4th generation to come:
CPV-4-U and the \emph{raison d'\^etre} for our Universe (and ourselves); 4-EWSB
and the \emph{raison d'\^etre} for the LHC itself.
| [
{
"created": "Tue, 11 Jan 2011 16:39:02 GMT",
"version": "v1"
}
] | 2011-04-22 | [
[
"Hou",
"George W. S.",
""
]
] | We pick up the thread of $B\to K\pi$ direct CPV (DCPV) difference, linking to the 4th generation prediction (and current quest) of $t$-dependent CPV (TCPV) in $B_s \to J/\psi\,\phi$. We then soar up to the heavens with possible source of CPV for the Universe (CPV-4-U); for the "cauldron" that stirs strong phase transitions, we raise the possible link between electroweak symmetry breaking and large Yukawa couplings (4-EWSB). With the prognosis for 2011, 2012 and beyond, we stress these as preview for the possible 4th generation to come: CPV-4-U and the \emph{raison d'\^etre} for our Universe (and ourselves); 4-EWSB and the \emph{raison d'\^etre} for the LHC itself. |
hep-ph/0208005 | Hitoshi Murayama | Hitoshi Murayama | GUT, Neutrinos, and Baryogenesis | Talk presented at 5th KEK Topical Conference: Frontiers In Flavor
Physics, 20-22 Nov 2001, Tsukuba, Ibaraki, Japan. Includes comments on SUSY
GUT contribution to B->phi Ks | Nucl.Phys.Proc.Suppl.111:136-145,2002 | 10.1016/S0920-5632(02)01696-1 | UCB-PTH-02/34, LBNL-51221 | hep-ph | null | It is an exciting time for flavor physics. In this talk, I discuss recent
topics in baryogenesis and leptogenesis in light of new data, and implications
in B and neutrino physics. I also discuss current situation of grand unified
theories concerning coupling unification, proton decay, and indirect
consequences in lepton flavor violation and B physics. I explain attempts to
understand the origin of flavor based on flavor symmetry, in particular
"anarchy" in neutrinos.
| [
{
"created": "Thu, 1 Aug 2002 17:30:15 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Murayama",
"Hitoshi",
""
]
] | It is an exciting time for flavor physics. In this talk, I discuss recent topics in baryogenesis and leptogenesis in light of new data, and implications in B and neutrino physics. I also discuss current situation of grand unified theories concerning coupling unification, proton decay, and indirect consequences in lepton flavor violation and B physics. I explain attempts to understand the origin of flavor based on flavor symmetry, in particular "anarchy" in neutrinos. |
hep-ph/0310107 | Alfonso Rosado | R. M. Garcia-Hidalgo and A. Rosado | Heavy boson production through the collision of an ultrahigh-energy
neutrino on a target nucleon | 20 pages, 6 figures | Mod.Phys.Lett.A20:1465-1482,2005 | 10.1142/S0217732305016464 | null | hep-ph | null | We discuss W and Z production through the deep inelastic neutrino-nucleon
scattering in the context of the standard model SU(3)x SU(2)x U(1) of the
strong and electroweak interactions. We find the cross section rates for the
process neutrino + nucleon --> lepton(-) + W(+) + X for the case of
ultrahigh-energy neutrinos colliding on a target nucleon.
| [
{
"created": "Thu, 9 Oct 2003 02:27:10 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Oct 2003 01:54:16 GMT",
"version": "v2"
},
{
"created": "Wed, 7 Apr 2004 23:29:26 GMT",
"version": "v3"
}
] | 2010-11-05 | [
[
"Garcia-Hidalgo",
"R. M.",
""
],
[
"Rosado",
"A.",
""
]
] | We discuss W and Z production through the deep inelastic neutrino-nucleon scattering in the context of the standard model SU(3)x SU(2)x U(1) of the strong and electroweak interactions. We find the cross section rates for the process neutrino + nucleon --> lepton(-) + W(+) + X for the case of ultrahigh-energy neutrinos colliding on a target nucleon. |
hep-ph/0112144 | Kirk Buckley | Kirk B.W. Buckley (University of British Columbia) | Classical stability of U(1)_A domain walls in dense matter QCD | 13 pages, 2 Postscript figures, typos corrected | Phys.Rev. D65 (2002) 125011 | 10.1103/PhysRevD.65.125011 | null | hep-ph | null | It was recently shown that there exists metastable U(1)_A domain wall
configurations in high-density QCD (\mu >> 1 GeV). In the following we will
assess the stability of such non-trivial field configurations at intermediate
densities (\mu < 1 GeV). The existence of such configurations at intermediate
densities could have interesting consequences for the physics of neutron stars
with high core density.
| [
{
"created": "Tue, 11 Dec 2001 02:44:46 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Jun 2002 18:58:01 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Buckley",
"Kirk B. W.",
"",
"University of British Columbia"
]
] | It was recently shown that there exists metastable U(1)_A domain wall configurations in high-density QCD (\mu >> 1 GeV). In the following we will assess the stability of such non-trivial field configurations at intermediate densities (\mu < 1 GeV). The existence of such configurations at intermediate densities could have interesting consequences for the physics of neutron stars with high core density. |
1107.0747 | Riazuddin Riazuddin | Riazuddin | Dynamical Symmetries of Dirac Hamiltonian | 15 pages, V3 typos removed and some new material included | null | 10.1142/S0217751X12300049 | null | hep-ph math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Several dynamical symmetries of the Dirac Hamiltonian are reviewed in a
systematic manner and the conditions under which such symmetries hold. These
include relativistic spin and orbital angular momentum symmetries, SO(4)\times
SU_{\sigma}(2) symmetry for the Dirac Hydrogen atom, SU(3)\times SU_{\sigma}(2)
symmetry for the relativistic simple harmonic oscillator. The energy spectrum
in each case is calculated from group-theoretic considerations.
| [
{
"created": "Mon, 4 Jul 2011 21:51:29 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Aug 2011 11:02:47 GMT",
"version": "v2"
},
{
"created": "Thu, 3 Nov 2011 05:29:06 GMT",
"version": "v3"
}
] | 2015-05-28 | [
[
"Riazuddin",
"",
""
]
] | Several dynamical symmetries of the Dirac Hamiltonian are reviewed in a systematic manner and the conditions under which such symmetries hold. These include relativistic spin and orbital angular momentum symmetries, SO(4)\times SU_{\sigma}(2) symmetry for the Dirac Hydrogen atom, SU(3)\times SU_{\sigma}(2) symmetry for the relativistic simple harmonic oscillator. The energy spectrum in each case is calculated from group-theoretic considerations. |
hep-ph/0303144 | XiaoHu Mo | P.Wang, C.Z.Yuan and X.H.Mo | Possible large phase in psi(2S) -> 1-0- Decays | 4 pages | Phys.Rev. D69 (2004) 057502 | 10.1103/PhysRevD.69.057502 | null | hep-ph | null | The strong and the electromagnetic amplitudes are analyzed on the basis of
the measurements of J/psi, psi(2S) -> 1-0- in e+e- experiments. The currently
available experimental information is revised with inclusion of the
contribution from e+e- -> gamma * -> 1-0- . The study shows that a large phase
around minus 90 degree between the strong and the electromagnetic amplitudes
could not be ruled out by the experimental data for psi(2S).
| [
{
"created": "Tue, 18 Mar 2003 07:18:48 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Mar 2004 03:46:52 GMT",
"version": "v2"
}
] | 2016-09-06 | [
[
"Wang",
"P.",
""
],
[
"Yuan",
"C. Z.",
""
],
[
"Mo",
"X. H.",
""
]
] | The strong and the electromagnetic amplitudes are analyzed on the basis of the measurements of J/psi, psi(2S) -> 1-0- in e+e- experiments. The currently available experimental information is revised with inclusion of the contribution from e+e- -> gamma * -> 1-0- . The study shows that a large phase around minus 90 degree between the strong and the electromagnetic amplitudes could not be ruled out by the experimental data for psi(2S). |
2003.05018 | Holger Frits Bech Nielsen | Colin D. Froggatt and Holger B. Nielsen | The 3.5 keV line from non-perturbative Standard Model dark matter balls | A factor 2 miscomputation was corrected, and a new value for the
potential difference $\Delta V{\pounds}$ used | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Our earlier put forward model of dark matter, consisting of cm-size pearls
with ordinary matter inside under high pressure and with a mass of order $1.4
*10^8$ kg, is used to explain the mysterious 3.5 keV X-ray line from the
galactic center and various galaxies and galaxy clusters. The pearls are
bubbles of a new type of vacuum and thus surrounded by a surface tension
providing the high pressure.
We have two rather successful order of magnitude numerical results:
1) the X-ray energy of 3.5 keV comes out as the homolumo-gap or rather as the
energy due to screening of electrons in the high pressure ordinary matter
inside the pearls, and is well fitted. %predicted correctly to within a factor
%{\bf tbc 2} %3; %$40 \%$;
2) Using the fitting of Cline and Frey for dark matter radiation arising from
collisions or annihilations of dark matter particles we fit the overall
intensity of the radiation in our pearl model.
We find that a pearl of the minimal size required just by stability, as used
in our previous work \cite{Tunguska}, is inconsistent with the observed
frequency and intensity of the 3.5 keV line. However the predictions of our
model are very sensitive to the radius of the pearls and an excellent fit to
both experimental quantities is obtained for a pearl of radius of 2.8 cm.
| [
{
"created": "Tue, 10 Mar 2020 22:02:24 GMT",
"version": "v1"
},
{
"created": "Sun, 5 Apr 2020 10:00:41 GMT",
"version": "v2"
},
{
"created": "Mon, 23 Nov 2020 00:04:12 GMT",
"version": "v3"
}
] | 2020-11-24 | [
[
"Froggatt",
"Colin D.",
""
],
[
"Nielsen",
"Holger B.",
""
]
] | Our earlier put forward model of dark matter, consisting of cm-size pearls with ordinary matter inside under high pressure and with a mass of order $1.4 *10^8$ kg, is used to explain the mysterious 3.5 keV X-ray line from the galactic center and various galaxies and galaxy clusters. The pearls are bubbles of a new type of vacuum and thus surrounded by a surface tension providing the high pressure. We have two rather successful order of magnitude numerical results: 1) the X-ray energy of 3.5 keV comes out as the homolumo-gap or rather as the energy due to screening of electrons in the high pressure ordinary matter inside the pearls, and is well fitted. %predicted correctly to within a factor %{\bf tbc 2} %3; %$40 \%$; 2) Using the fitting of Cline and Frey for dark matter radiation arising from collisions or annihilations of dark matter particles we fit the overall intensity of the radiation in our pearl model. We find that a pearl of the minimal size required just by stability, as used in our previous work \cite{Tunguska}, is inconsistent with the observed frequency and intensity of the 3.5 keV line. However the predictions of our model are very sensitive to the radius of the pearls and an excellent fit to both experimental quantities is obtained for a pearl of radius of 2.8 cm. |
hep-ph/0103286 | Vassili Plyaskine | Vassily Plyaskin (Institute of Theoretical and Experimental Physics,
Moscow) | Calculation of atmospheric neutrino flux | 47 pages, 38 pictures. Latex.To correct for a technical error the
neutrino fluxes and event rates at different sites are multiplied by a factor
pi/2 | Phys.Lett.B516:213-235,2001 | 10.1016/S0370-2693(01)00907-8 | null | hep-ph | null | A calculation of the fluxes of primary particles arriving to the Earth's
vicinity as well as those produced in the interactions of the primaries with
the atmosphere is presented. The result of calculations is compared with the
experimental data obtained with the Alpha Magnetic Spectrometer (AMS). A good
agreement of calculated and measured fluxes of charged particles supports the
viability of the atmospheric neutrino flux calculation.
| [
{
"created": "Tue, 27 Mar 2001 15:24:07 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Mar 2001 12:35:59 GMT",
"version": "v2"
},
{
"created": "Sat, 18 May 2002 11:00:43 GMT",
"version": "v3"
}
] | 2010-05-28 | [
[
"Plyaskin",
"Vassily",
"",
"Institute of Theoretical and Experimental Physics,\n Moscow"
]
] | A calculation of the fluxes of primary particles arriving to the Earth's vicinity as well as those produced in the interactions of the primaries with the atmosphere is presented. The result of calculations is compared with the experimental data obtained with the Alpha Magnetic Spectrometer (AMS). A good agreement of calculated and measured fluxes of charged particles supports the viability of the atmospheric neutrino flux calculation. |
hep-ph/0407331 | Kazuo Fujikawa | Kazuo Fujikawa | Remark on Natural Models of Neutrinos | 13 pages. Modified the title, abstract and the body of the paper. To
be published in Prog. Theor. Phys | Prog.Theor.Phys. 113 (2005) 1065 | 10.1143/PTP.113.1065 | NUP-A-2004-4 | hep-ph | null | We comment on what the naturalness argument of 't Hooft implies for a minimal
extension of the standard model which incorporates right-handed neutrinos with
generic mass terms. If this Lagrangian is taken as a low energy effective
theory, the idea of pseudo-Dirac neutrinos with very small masses is consistent
with the naturalness argument of 't Hooft. This argument is based on an
observation that the right-handed components of neutrinos in the massless limit
exhibit an extra enhanced symmetry which is absent in other charged fermions.
This enhanced symmetry is reminiscent of the Nambu-Goldstone fermions
associated with spontaneously broken supersymmetry. The conventional seesaw
scenario gives another natural solution if the ultra-heavy right-handed
neutrinos are integrated out in defining a low energy effective theory.
| [
{
"created": "Thu, 29 Jul 2004 05:51:15 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Mar 2005 09:20:04 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Fujikawa",
"Kazuo",
""
]
] | We comment on what the naturalness argument of 't Hooft implies for a minimal extension of the standard model which incorporates right-handed neutrinos with generic mass terms. If this Lagrangian is taken as a low energy effective theory, the idea of pseudo-Dirac neutrinos with very small masses is consistent with the naturalness argument of 't Hooft. This argument is based on an observation that the right-handed components of neutrinos in the massless limit exhibit an extra enhanced symmetry which is absent in other charged fermions. This enhanced symmetry is reminiscent of the Nambu-Goldstone fermions associated with spontaneously broken supersymmetry. The conventional seesaw scenario gives another natural solution if the ultra-heavy right-handed neutrinos are integrated out in defining a low energy effective theory. |
1305.4676 | Jonathan Cornell | Jonathan M. Cornell, Stefano Profumo and William Shepherd | Kinetic Decoupling and Small-Scale Structure in Effective Theories of
Dark Matter | 29 pages, 6 figures, captions and one figure corrected, accepted for
publication in PRD | Phys. Rev. D 88, 015027 (2013) | 10.1103/PhysRevD.88.015027 | null | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The size of the smallest dark matter collapsed structures, or protohalos, is
set by the temperature at which dark matter particles fall out of kinetic
equilibrium. The process of kinetic decoupling involves elastic scattering of
dark matter off of Standard Model particles in the early universe, and the
relevant cross section is thus closely related to the cross section for dark
matter scattering off of nuclei (direct detection) but also, via crossing
symmetries, for dark matter pair production at colliders and for pair
annihilation. In this study, we employ an effective field theoretic approach to
calculate constraints on the kinetic decoupling temperature, and thus on the
size of the smallest protohalos, from a variety of direct, indirect and
collider probes of particle dark matter.
| [
{
"created": "Mon, 20 May 2013 23:17:08 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Jul 2013 13:23:20 GMT",
"version": "v2"
}
] | 2013-07-30 | [
[
"Cornell",
"Jonathan M.",
""
],
[
"Profumo",
"Stefano",
""
],
[
"Shepherd",
"William",
""
]
] | The size of the smallest dark matter collapsed structures, or protohalos, is set by the temperature at which dark matter particles fall out of kinetic equilibrium. The process of kinetic decoupling involves elastic scattering of dark matter off of Standard Model particles in the early universe, and the relevant cross section is thus closely related to the cross section for dark matter scattering off of nuclei (direct detection) but also, via crossing symmetries, for dark matter pair production at colliders and for pair annihilation. In this study, we employ an effective field theoretic approach to calculate constraints on the kinetic decoupling temperature, and thus on the size of the smallest protohalos, from a variety of direct, indirect and collider probes of particle dark matter. |
1608.07414 | Renata Jora | Amir H. Fariborz, Renata Jora, Salah Nasri | Mass Ansatze for the standard model fermions from a composite
perspective | 8 pages, 2 figures, typo in the affiliation fixed | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a composite model in which the standard model fermions are bound
states of elementary spin $\frac{1}{2}$ particles, the preons, situated in the
conjugate product representation of the color group. In this framework we
propose and analyze two mass Ansatze one for the leptons, the other one for the
quarks, based on mass formulae of the Gell-Mann Okubo type. We find that these
mass Ansatze can give an adequate description of the known standard model
fermion masses.
| [
{
"created": "Fri, 26 Aug 2016 10:13:24 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Aug 2016 02:55:59 GMT",
"version": "v2"
}
] | 2016-08-30 | [
[
"Fariborz",
"Amir H.",
""
],
[
"Jora",
"Renata",
""
],
[
"Nasri",
"Salah",
""
]
] | We consider a composite model in which the standard model fermions are bound states of elementary spin $\frac{1}{2}$ particles, the preons, situated in the conjugate product representation of the color group. In this framework we propose and analyze two mass Ansatze one for the leptons, the other one for the quarks, based on mass formulae of the Gell-Mann Okubo type. We find that these mass Ansatze can give an adequate description of the known standard model fermion masses. |
hep-ph/9711219 | Taekoon Lee | Taekoon Lee | Higher Order Renormalons | 6 pages. Presented at VIIth Blois Workshop at Seoul, Korea, June
10-14, 1997 | null | null | PURD-TH-97-08 | hep-ph | null | A systematic method of summing the corrections to the renormalon residue
arising from higher order renormalons is discussed.
| [
{
"created": "Tue, 4 Nov 1997 03:32:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lee",
"Taekoon",
""
]
] | A systematic method of summing the corrections to the renormalon residue arising from higher order renormalons is discussed. |
2310.14033 | Ilidio Lopes | Il\'idio Lopes | Linking solar bosonic dark matter halos and active neutrinos | 13 pages, 1 table, 5 figures. Article published in Physical Review D, | Physical Review D 108, 083028 (2023) | 10.1103/PhysRevD.108.083028 | null | hep-ph astro-ph.CO astro-ph.SR hep-ex hep-th | http://creativecommons.org/licenses/by-nc-sa/4.0/ | Our study investigates the complex interaction between active neutrinos and
the ultralight bosonic dark matter halo surrounding the Sun. This halo extends
over several solar radii due to the Sun's gravitational field, and we represent
it as a coherent oscillating classical field configuration of bosonic dark
matter particles that vary in time. Our investigation has revealed that, based
on the available solar neutrino flux data, these novel models do not surpass
the performance of the conventional neutrino flavour oscillation model.
Furthermore, we discuss how next-generation solar neutrino detectors have the
potential to provide evidence for the existence or absence of the ultralight
dark matter halo.
| [
{
"created": "Sat, 21 Oct 2023 15:07:45 GMT",
"version": "v1"
}
] | 2023-10-24 | [
[
"Lopes",
"Ilídio",
""
]
] | Our study investigates the complex interaction between active neutrinos and the ultralight bosonic dark matter halo surrounding the Sun. This halo extends over several solar radii due to the Sun's gravitational field, and we represent it as a coherent oscillating classical field configuration of bosonic dark matter particles that vary in time. Our investigation has revealed that, based on the available solar neutrino flux data, these novel models do not surpass the performance of the conventional neutrino flavour oscillation model. Furthermore, we discuss how next-generation solar neutrino detectors have the potential to provide evidence for the existence or absence of the ultralight dark matter halo. |
2203.01336 | Giuseppe Lucente | Giuseppe Lucente, Oscar Straniero, Pierluca Carenza, Maurizio
Giannotti, Alessandro Mirizzi | Constraining heavy axion-like particles by energy deposition in Globular
Cluster stars | 13 pages, 7 figures. Typos corrected. More details on the ballistic
model and the constraining method added | Physical Review Letters 129, 011101 (2022) | 10.1103/PhysRevLett.129.011101 | null | hep-ph astro-ph.SR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Heavy axion-like particles (ALPs), with masses up to a few 100 keV and
coupled with photons can be efficiently produced in stellar plasmas,
contributing to a significant energy-loss. This argument has been applied to
helium burning stars in Globular Clusters (GCs) to obtain stringent bounds on
the ALP-photon coupling $g_{a\gamma}$. However, for sufficiently large values
of the ALP mass and coupling to photons, one should expect a significant
fraction of ALPs to decay inside the star. These ALPs do not contribute to the
energy loss but rather lead to an efficient energy transfer inside the star. We
present a new ballistic recipe that covers both the energy-loss and
energy-transfer regimes and we perform the first dedicated simulation of GC
stars including the ALP energy transfer. This argument allows us to constrain
ALPs with $m_a \lesssim 0.4$ MeV and $g_{a\gamma} \simeq 10^{-5}$ GeV$^{-1}$,
probing a section of the ALP parameter space informally known as "cosmological
triangle". This region is particularly interesting since it has been excluded
only using standard cosmological arguments that can be evaded in nonstandard
scenarios.
| [
{
"created": "Wed, 2 Mar 2022 19:00:02 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Jun 2022 16:12:32 GMT",
"version": "v2"
}
] | 2022-06-30 | [
[
"Lucente",
"Giuseppe",
""
],
[
"Straniero",
"Oscar",
""
],
[
"Carenza",
"Pierluca",
""
],
[
"Giannotti",
"Maurizio",
""
],
[
"Mirizzi",
"Alessandro",
""
]
] | Heavy axion-like particles (ALPs), with masses up to a few 100 keV and coupled with photons can be efficiently produced in stellar plasmas, contributing to a significant energy-loss. This argument has been applied to helium burning stars in Globular Clusters (GCs) to obtain stringent bounds on the ALP-photon coupling $g_{a\gamma}$. However, for sufficiently large values of the ALP mass and coupling to photons, one should expect a significant fraction of ALPs to decay inside the star. These ALPs do not contribute to the energy loss but rather lead to an efficient energy transfer inside the star. We present a new ballistic recipe that covers both the energy-loss and energy-transfer regimes and we perform the first dedicated simulation of GC stars including the ALP energy transfer. This argument allows us to constrain ALPs with $m_a \lesssim 0.4$ MeV and $g_{a\gamma} \simeq 10^{-5}$ GeV$^{-1}$, probing a section of the ALP parameter space informally known as "cosmological triangle". This region is particularly interesting since it has been excluded only using standard cosmological arguments that can be evaded in nonstandard scenarios. |
0809.0785 | J.D. Vergados | J. D. Vergados (Physics Department, University of Ioannina, Ioannina,
Greece and Theory Division, CERN), H. Ejiri (RCNP, Osaka University, Osaka,
Japan and National Institute of Radiological Sciences, Chiba, Japan), I.
Giomataris (IRFU, Centre d'etudes de Saclay, Gif sur Yvette CEDEX, France) | Solar Neutrinos as Background in Direct Dark Matter Searches | 6 pages, 5 figures, Submitted for the DSU proceedings to be published
by the American institute of Physics (AIP). References added | AIP Conf.Proc.1115:7-12,2009 | 10.1063/1.3131532 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The coherent contribution of all neutrons in neutrino nucleus scattering due
to the neutral current is examined considering the boron solar neutrinos. These
neutrinos could potentially become a source of background in the future dark
matter searches aiming at nucleon cross sections in the region well below the
few events per ton per year.
| [
{
"created": "Thu, 4 Sep 2008 11:03:02 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Sep 2008 08:12:57 GMT",
"version": "v2"
},
{
"created": "Tue, 16 Sep 2008 10:52:35 GMT",
"version": "v3"
}
] | 2009-05-01 | [
[
"Vergados",
"J. D.",
"",
"Physics Department, University of Ioannina, Ioannina,\n Greece and Theory Division, CERN"
],
[
"Ejiri",
"H.",
"",
"RCNP, Osaka University, Osaka,\n Japan and National Institute of Radiological Sciences, Chiba, Japan"
],
[
"Giomataris",
"I... | The coherent contribution of all neutrons in neutrino nucleus scattering due to the neutral current is examined considering the boron solar neutrinos. These neutrinos could potentially become a source of background in the future dark matter searches aiming at nucleon cross sections in the region well below the few events per ton per year. |
0709.4535 | Viacheslav Bunichev | E. Boos (1), V. Bunichev (1), H. J. Schreiber (2) ((1) Skobeltsyn
Institute of Nuclear Physics, MSU, Moscow, Russia, (2) DESY, Deutsches
Elektronen-Synchrotron, Zeuthen, Germany) | Prospects of a Search for a New Massless Neutral Gauge Boson at the ILC | 17 pages, 7 figures | Phys.Rev.D78:015007,2008 | 10.1103/PhysRevD.78.015007 | null | hep-ph | null | Prospects to search for a new massless neutral gauge boson, the paraphoton,
in e+ e- collisions at center-of-mass energies of 0.5 and 1 TeV are studied.
The paraphoton naturally appears in models with abelian kinetic mixing. A
possible realistic model independent lowest order effective Lagrangian contains
magnetic interactions of the paraphoton with the Standard Model fermion fields.
These interactions are proportional to the fermion mass and grow with energy,
with however very weak paraphoton couplings to ordinary matter. At the ILC, a
potentially interesting process to search for the paraphoton is its radiation
off top quarks, so that the event topology to be searched for is a pair of
acoplanar top quark jets with missing energy. By combining many discriminating
features of signal and background events efficient paraphoton event selection
was achieved allowing to set limits for the top-paraphoton coupling. Arguments
in favor of the missing energy as the paraphoton with spin 1 are discussed.
| [
{
"created": "Fri, 28 Sep 2007 14:53:36 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Boos",
"E.",
""
],
[
"Bunichev",
"V.",
""
],
[
"Schreiber",
"H. J.",
""
]
] | Prospects to search for a new massless neutral gauge boson, the paraphoton, in e+ e- collisions at center-of-mass energies of 0.5 and 1 TeV are studied. The paraphoton naturally appears in models with abelian kinetic mixing. A possible realistic model independent lowest order effective Lagrangian contains magnetic interactions of the paraphoton with the Standard Model fermion fields. These interactions are proportional to the fermion mass and grow with energy, with however very weak paraphoton couplings to ordinary matter. At the ILC, a potentially interesting process to search for the paraphoton is its radiation off top quarks, so that the event topology to be searched for is a pair of acoplanar top quark jets with missing energy. By combining many discriminating features of signal and background events efficient paraphoton event selection was achieved allowing to set limits for the top-paraphoton coupling. Arguments in favor of the missing energy as the paraphoton with spin 1 are discussed. |
hep-ph/9411421 | null | Yuri Novozhilov, Andrei Pronko and Dmitri Vassilevich | Extended Chiral Transformations Including Diquark Fields as Parameters | Latex file, to apear in Phis. Lett. B | Phys.Lett. B343 (1995) 358-362; Erratum-ibid. B351 (1995) 601 | 10.1016/0370-2693(94)01451-H | SPbU-IP-94-17 | hep-ph | null | We introduce extended chiral transformation, which depends both on
pseudoscalar and diquark fields as parameters and determine its group
structure. Assuming soft symmetry breaking in diquark sector, bosonisation of a
quasi-Goldstone $ud$-diquark is performed. In the chiral limit the $ud$-diquark
mass is defined by the gluon condensate, $m_{ud}\approx 300 MeV$. The diquark
charge radius is $\langle r^2_{ud}\rangle^{1/2}\approx 0.5 fm$.
| [
{
"created": "Tue, 29 Nov 1994 14:23:53 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Novozhilov",
"Yuri",
""
],
[
"Pronko",
"Andrei",
""
],
[
"Vassilevich",
"Dmitri",
""
]
] | We introduce extended chiral transformation, which depends both on pseudoscalar and diquark fields as parameters and determine its group structure. Assuming soft symmetry breaking in diquark sector, bosonisation of a quasi-Goldstone $ud$-diquark is performed. In the chiral limit the $ud$-diquark mass is defined by the gluon condensate, $m_{ud}\approx 300 MeV$. The diquark charge radius is $\langle r^2_{ud}\rangle^{1/2}\approx 0.5 fm$. |
1109.3130 | Hua-Xing Chen | Hua-Xing Chen, V. Dmitrasinovic and Atsushi Hosaka | Baryons with U_L(3)*U_R(3) Chiral Symmetry IV: Interactions with Chiral
(8,1)+(1,8) Vector and Axial-vector Mesons and Anomalous Magnetic Moments | 16 pages, 2 tables, accepted by PRC | Phys.Rev.C85:055205,2012 | 10.1103/PhysRevC.85.055205 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct all SU_L(3)*SU_R(3) chirally invariant anomalous magnetic, i.e.
involving a Pauli tensor and one-derivative, interactions of one
chiral-[(8,1)+(1,8)] meson field with chiral-[(6,3)+(3,6)],
[(3,\bar3)+(\bar3,3)], and [(8,1)+(1,8)] baryon fields and their "mirror"
images. We find strong chiral selection rules: e.g. there is only one
off-diagonal chirally symmetric anomalous magnetic interaction between J=1/2
fields belonging to the [(6,3)+(3,6)] and the [(3,\bar3)+(\bar3,3)] chiral
multiplets. We also study the chiral selection rules for the anomalous magnetic
interactions of the [(3,\bar3)+(\bar3,3)] and the [(8,1)+(1,8)] baryon fields.
Again, no diagonal and only one off-diagonal chiral SU_L(3)*SU_R(3) interaction
of this type is allowed, that turns out also to conserve the U_A(1) symmetry.
We calculate the F/D ratios for the baryons' anomalous magnetic moments
predicted by these interactions in the SU(3) symmetry limit and find that only
the [(6,3)+(3,6)]-[(3,\bar3)+(\bar3,3)] one, reproduces F/D=1/3, in close
proximity to the value extracted from experiment.
| [
{
"created": "Wed, 14 Sep 2011 16:43:00 GMT",
"version": "v1"
},
{
"created": "Fri, 11 May 2012 09:59:16 GMT",
"version": "v2"
}
] | 2012-06-07 | [
[
"Chen",
"Hua-Xing",
""
],
[
"Dmitrasinovic",
"V.",
""
],
[
"Hosaka",
"Atsushi",
""
]
] | We construct all SU_L(3)*SU_R(3) chirally invariant anomalous magnetic, i.e. involving a Pauli tensor and one-derivative, interactions of one chiral-[(8,1)+(1,8)] meson field with chiral-[(6,3)+(3,6)], [(3,\bar3)+(\bar3,3)], and [(8,1)+(1,8)] baryon fields and their "mirror" images. We find strong chiral selection rules: e.g. there is only one off-diagonal chirally symmetric anomalous magnetic interaction between J=1/2 fields belonging to the [(6,3)+(3,6)] and the [(3,\bar3)+(\bar3,3)] chiral multiplets. We also study the chiral selection rules for the anomalous magnetic interactions of the [(3,\bar3)+(\bar3,3)] and the [(8,1)+(1,8)] baryon fields. Again, no diagonal and only one off-diagonal chiral SU_L(3)*SU_R(3) interaction of this type is allowed, that turns out also to conserve the U_A(1) symmetry. We calculate the F/D ratios for the baryons' anomalous magnetic moments predicted by these interactions in the SU(3) symmetry limit and find that only the [(6,3)+(3,6)]-[(3,\bar3)+(\bar3,3)] one, reproduces F/D=1/3, in close proximity to the value extracted from experiment. |
2403.08117 | Nicholas Hunt-Smith | N. T. Hunt-Smith, C. Cocuzza, W. Melnitchouk, N. Sato, A. W Thomas, M.
J. White | On the resolution of the sign of gluon polarization in the proton | null | null | null | null | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently the possible existence of negative gluon helicity, $\Delta g$, has
been observed to be compatible with existing empirical constraints, including
from jet production in polarized proton-proton collisions at RHIC, and lattice
QCD data on polarized gluon Ioffe time distributions. We perform a new global
analysis of polarized parton distributions in the proton with new constraints
from the high-$x$ region of deep-inelastic scattering (DIS). A dramatic
reduction in the quality of the fit for the negative $\Delta g$ replicas
compared to those with positive $\Delta g$ suggest that the negative $\Delta g$
solution cannot simultaneously account for high-$x$ polarized DIS data along
with lattice and polarized jet data.
| [
{
"created": "Tue, 12 Mar 2024 22:57:38 GMT",
"version": "v1"
}
] | 2024-03-15 | [
[
"Hunt-Smith",
"N. T.",
""
],
[
"Cocuzza",
"C.",
""
],
[
"Melnitchouk",
"W.",
""
],
[
"Sato",
"N.",
""
],
[
"Thomas",
"A. W",
""
],
[
"White",
"M. J.",
""
]
] | Recently the possible existence of negative gluon helicity, $\Delta g$, has been observed to be compatible with existing empirical constraints, including from jet production in polarized proton-proton collisions at RHIC, and lattice QCD data on polarized gluon Ioffe time distributions. We perform a new global analysis of polarized parton distributions in the proton with new constraints from the high-$x$ region of deep-inelastic scattering (DIS). A dramatic reduction in the quality of the fit for the negative $\Delta g$ replicas compared to those with positive $\Delta g$ suggest that the negative $\Delta g$ solution cannot simultaneously account for high-$x$ polarized DIS data along with lattice and polarized jet data. |
2403.17738 | Xing Wang | Martin Beneke, Yao Ji, and Xing Wang | Renormalization of the next-to-leading-power $\gamma\gamma \to h $ and
$gg\to h$ soft quark functions | journal version | JHEP05(2024)246 | 10.1007/JHEP05(2024)246 | TUM-HEP-1501/24 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We calculate directly in position space the one-loop renormalization kernels
of the soft operators $O_\gamma$ and $O_g$ that appear in the soft-quark
contributions to, respectively, the subleading-power $\gamma\gamma\to h$ and
$gg\to h$ form factors mediated by the $b$-quark. We present an IR/rapidity
divergence-free definition for $O_g$ and demonstrate that with a correspondent
definition of the collinear function, a consistent factorization theorem is
recovered. Using conformal symmetry techniques, we establish a relation between
the evolution kernels of the leading-twist heavy-light light-ray operator,
whose matrix element defines the $B$-meson light-cone distribution amplitude
(LCDA), and $O_\gamma$ to all orders in perturbation theory. Application of
this relation allows us to bootstrap the kernel of $O_\gamma$ to the two-loop
level. We construct an ansatz for the kernel of $O_g$ at higher orders. We test
this ansatz against the consistency requirement at two-loop and find they
differ only by a particular constant.
| [
{
"created": "Tue, 26 Mar 2024 14:27:06 GMT",
"version": "v1"
},
{
"created": "Wed, 22 May 2024 19:33:24 GMT",
"version": "v2"
}
] | 2024-05-24 | [
[
"Beneke",
"Martin",
""
],
[
"Ji",
"Yao",
""
],
[
"Wang",
"Xing",
""
]
] | We calculate directly in position space the one-loop renormalization kernels of the soft operators $O_\gamma$ and $O_g$ that appear in the soft-quark contributions to, respectively, the subleading-power $\gamma\gamma\to h$ and $gg\to h$ form factors mediated by the $b$-quark. We present an IR/rapidity divergence-free definition for $O_g$ and demonstrate that with a correspondent definition of the collinear function, a consistent factorization theorem is recovered. Using conformal symmetry techniques, we establish a relation between the evolution kernels of the leading-twist heavy-light light-ray operator, whose matrix element defines the $B$-meson light-cone distribution amplitude (LCDA), and $O_\gamma$ to all orders in perturbation theory. Application of this relation allows us to bootstrap the kernel of $O_\gamma$ to the two-loop level. We construct an ansatz for the kernel of $O_g$ at higher orders. We test this ansatz against the consistency requirement at two-loop and find they differ only by a particular constant. |
2307.00646 | Satyabrata Datta | Satyabrata Datta and Rome Samanta | Fingerprint of GeV scale right-handed neutrinos on inflationary
gravitational waves and PTA data | 7+3 pages, 2 captioned figures, significantly revised, title changed,
an additional author, accepted for publication in Phys. Rev. D Letter | null | 10.1103/PhysRevD.108.L091706 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that the seesaw mechanisms that exhibit right-handed neutrino
mass-dependent non-standard post-inflationary cosmology make blue-tilted
inflationary gravitational waves (GW) compatible with the recent findings of
nHz stochastic GW background by the pulsar-timing arrays (PTAs) for high
reheating temperatures. The right-handed neutrino (RHN) mass scale has to be
$\mathcal{O}(\rm GeV)$. Remarkably, such a scenario produces a correlated
signature testable by the future LIGO run. In addition to contributing to the
active neutrino masses, $\mathcal{O}(\rm GeV)$ RHNs generate baryon asymmetry
of the universe via low-scale-leptogenesis. They can be searched for in
collider experiments. Therefore, the recent detection by PTAs is not only
exciting for GWs in the nHz range; it paves the way to test and constrain
well-studied mechanisms, such as seesaws, with a low-frequency and a correlated
measurement of high-frequency GW spectral features, complementary to particle
physics searches.
| [
{
"created": "Sun, 2 Jul 2023 19:50:22 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Nov 2023 12:52:18 GMT",
"version": "v2"
}
] | 2023-12-05 | [
[
"Datta",
"Satyabrata",
""
],
[
"Samanta",
"Rome",
""
]
] | We show that the seesaw mechanisms that exhibit right-handed neutrino mass-dependent non-standard post-inflationary cosmology make blue-tilted inflationary gravitational waves (GW) compatible with the recent findings of nHz stochastic GW background by the pulsar-timing arrays (PTAs) for high reheating temperatures. The right-handed neutrino (RHN) mass scale has to be $\mathcal{O}(\rm GeV)$. Remarkably, such a scenario produces a correlated signature testable by the future LIGO run. In addition to contributing to the active neutrino masses, $\mathcal{O}(\rm GeV)$ RHNs generate baryon asymmetry of the universe via low-scale-leptogenesis. They can be searched for in collider experiments. Therefore, the recent detection by PTAs is not only exciting for GWs in the nHz range; it paves the way to test and constrain well-studied mechanisms, such as seesaws, with a low-frequency and a correlated measurement of high-frequency GW spectral features, complementary to particle physics searches. |
1511.06745 | Alan Chodos | Alan Chodos | A Model of Neutrinos | 11 pages, no figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a model for neutrinos based on symmetry under light-cone
reflection (LCR), which was introduced in a previous paper. LCR is realized
using a minimal substitution, which allows the equations of motion to be solved
after a suitable coordinate transformation. Some consequences of this proposal
are discussed.
| [
{
"created": "Fri, 20 Nov 2015 20:18:16 GMT",
"version": "v1"
}
] | 2015-11-23 | [
[
"Chodos",
"Alan",
""
]
] | We propose a model for neutrinos based on symmetry under light-cone reflection (LCR), which was introduced in a previous paper. LCR is realized using a minimal substitution, which allows the equations of motion to be solved after a suitable coordinate transformation. Some consequences of this proposal are discussed. |
hep-ph/9511429 | Oshimo | Noriyuki Oshimo | Signatures of Supersymmetry at B-Factories | 12 pages; To be published in the proceedings of the Yukawa
International Seminar '95 | Prog.Theor.Phys.Suppl. 123 (1996) 231-240 | 10.1143/PTPS.123.231 | OCHA-PP-68 | hep-ph | null | We discuss CP asymmetries in $B^0$-meson decays and \BsBs mixing within the
framework of the supersymmetric standard model (SSM). It is shown that \BdBd
and \KK mixings could receive sizable new contributions through box diagrams
mediated by the charginos and charged Higgs bosons. This implies that the
CP-violating phase of the Cabibbo-Kobayashi-Maskawa matrix may have a value
which is different from the one predicted by the standard model (SM). The value
of the CP-violating phase affects the amounts of the CP asymmetries and \BsBs
mixing. We examine predictions for these quantities in both the SSM and the SM,
exploring the difference between the two models.
| [
{
"created": "Tue, 28 Nov 1995 07:19:23 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Oshimo",
"Noriyuki",
""
]
] | We discuss CP asymmetries in $B^0$-meson decays and \BsBs mixing within the framework of the supersymmetric standard model (SSM). It is shown that \BdBd and \KK mixings could receive sizable new contributions through box diagrams mediated by the charginos and charged Higgs bosons. This implies that the CP-violating phase of the Cabibbo-Kobayashi-Maskawa matrix may have a value which is different from the one predicted by the standard model (SM). The value of the CP-violating phase affects the amounts of the CP asymmetries and \BsBs mixing. We examine predictions for these quantities in both the SSM and the SM, exploring the difference between the two models. |
1305.1100 | Mei Huang | Jingyi Chao, Pengcheng Chu, Mei Huang | Inverse magnetic catalysis induced by sphalerons | 5 pages, 3 figures | null | 10.1103/PhysRevD.88.054009 | null | hep-ph hep-lat hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recently discovered inverse magnetic catalysis around the critical
temperature indicates that some important information is missing in our current
understanding of conventional chiral dynamics of QCD, which is enhanced by the
magnetic field. In this work, we provide a mechanism to explain that the
inverse magnetic catalysis around the critical temperature is induced by
sphalerons. At high temperatures, sphaleron transitions between distinct
classical vacua cause an asymmetry between the number of right- and left-handed
quarks due to the axial anomaly of QCD. In the presence of a strong magnetic
field, the chiral imbalance is enhanced and destroys the right- and left-handed
pairings, which naturally induces a decreasing critical temperature of the
chiral phase transition for increasing magnetic field. The inverse magnetic
catalysis at finite baryon density, and the critical end point in the presence
of a strong magnetic field is also explored in this work.
| [
{
"created": "Mon, 6 May 2013 07:38:52 GMT",
"version": "v1"
}
] | 2013-09-11 | [
[
"Chao",
"Jingyi",
""
],
[
"Chu",
"Pengcheng",
""
],
[
"Huang",
"Mei",
""
]
] | The recently discovered inverse magnetic catalysis around the critical temperature indicates that some important information is missing in our current understanding of conventional chiral dynamics of QCD, which is enhanced by the magnetic field. In this work, we provide a mechanism to explain that the inverse magnetic catalysis around the critical temperature is induced by sphalerons. At high temperatures, sphaleron transitions between distinct classical vacua cause an asymmetry between the number of right- and left-handed quarks due to the axial anomaly of QCD. In the presence of a strong magnetic field, the chiral imbalance is enhanced and destroys the right- and left-handed pairings, which naturally induces a decreasing critical temperature of the chiral phase transition for increasing magnetic field. The inverse magnetic catalysis at finite baryon density, and the critical end point in the presence of a strong magnetic field is also explored in this work. |
hep-ph/9712305 | null | Howard Baer, Michal Brhlik, Diego Castano and Xerxes Tata | $b\to s\gamma$ Constraints on the Minimal Supergravity Model with Large
$\tan\beta$ | 14 page REVTEX file plus 6 PS figures | Phys.Rev. D58 (1998) 015007 | 10.1103/PhysRevD.58.015007 | FSU-HEP-971104, UH-511-887-97, UM-TH-97-19 | hep-ph | null | In the minimal supergravity model (mSUGRA), as the parameter $\tan\beta$
increases, the charged Higgs boson and light bottom squark masses decrease,
which can potentially increase contributions from $tH^\pm$, $\tg\tb_j$ and
$\tz_i\tb_j$ loops in the decay $b\to s\gamma$. We update a previous QCD
improved $b\to s\gamma$ decay calculation to include in addition the effects of
gluino and neutralino loops. We find that in the mSUGRA model, loops involving
charginos also increase, and dominate over $tW$, $tH^\pm$, $\tg\tq$ and
$\tz_i\tq$ contributions for $\tan\beta\agt 5-10$. We find for large values of
$\tan\beta \sim 35$ that most of the parameter space of the mSUGRA model for
$\mu <0$ is ruled out due to too large a value of branching ratio $B(b\to
s\gamma)$. For $\mu >0$ and large $\tan\beta$, most of parameter space is
allowed, although the regions with the least fine-tuning (low $m_0$ and
$m_{1/2}$) are ruled out due to too low a value of $B(b\to s\gamma)$. We
compare the constraints from $b\to s\gamma$ to constraints from the neutralino
relic density, and to expectations for sparticle discovery at LEP2 and the
Fermilab Tevatron $p\bar p$ colliders. Finally, we show that non-universal GUT
scale soft breaking squark mass terms can enhance gluino loop contributions to
$b\to s\gamma$ decay rate even if these are diagonal.
| [
{
"created": "Mon, 8 Dec 1997 21:28:04 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Baer",
"Howard",
""
],
[
"Brhlik",
"Michal",
""
],
[
"Castano",
"Diego",
""
],
[
"Tata",
"Xerxes",
""
]
] | In the minimal supergravity model (mSUGRA), as the parameter $\tan\beta$ increases, the charged Higgs boson and light bottom squark masses decrease, which can potentially increase contributions from $tH^\pm$, $\tg\tb_j$ and $\tz_i\tb_j$ loops in the decay $b\to s\gamma$. We update a previous QCD improved $b\to s\gamma$ decay calculation to include in addition the effects of gluino and neutralino loops. We find that in the mSUGRA model, loops involving charginos also increase, and dominate over $tW$, $tH^\pm$, $\tg\tq$ and $\tz_i\tq$ contributions for $\tan\beta\agt 5-10$. We find for large values of $\tan\beta \sim 35$ that most of the parameter space of the mSUGRA model for $\mu <0$ is ruled out due to too large a value of branching ratio $B(b\to s\gamma)$. For $\mu >0$ and large $\tan\beta$, most of parameter space is allowed, although the regions with the least fine-tuning (low $m_0$ and $m_{1/2}$) are ruled out due to too low a value of $B(b\to s\gamma)$. We compare the constraints from $b\to s\gamma$ to constraints from the neutralino relic density, and to expectations for sparticle discovery at LEP2 and the Fermilab Tevatron $p\bar p$ colliders. Finally, we show that non-universal GUT scale soft breaking squark mass terms can enhance gluino loop contributions to $b\to s\gamma$ decay rate even if these are diagonal. |
2204.05085 | Wei Su | Huayang Song, Wei Su, Mengchao Zhang | Electroweak Phase Transition in 2HDM under Higgs, Z-pole, and W
precision measurements | 17 pages, 3 figure | null | 10.1007/JHEP10(2022)048 | KIAS--P22020 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this work we revisit the existence of a strong first order electroweak
phase transition (SFOEWPT) and recent $m_W$ precision measurement in the Type-I
and Type-II 2HDMs. The O(100) GeV new scalars in 2HDMs are favored by SFOEWPT,
which is necessary for electroweak baryogenesis, and observed $m_W$ shift as
well. % We find that under current constraints, both Type-I and Type-II 2HDM
can explain the SFOEWPT, Z-pole, Higgs precision measurements and $m_W$
precision measurement of CDF-II at same time, and all these precision
measurements are sensitive to heavy Higgs mass splitting in 2HDM. The allowed
regions are $\Delta m_{A/C} \in (-400, 400) GeV, \tanb\in(1,50)$, and $\Delta
m_{A/C} \in (-200, 300) GeV, \tanb\in(1,12)$ for Type-I and Type-II 2HDM
respectively. Furthermore future lepton collider measurements on Higgs and $Z$
boson properties can explore this scenario in more detail or even rule out it.
| [
{
"created": "Mon, 11 Apr 2022 13:36:25 GMT",
"version": "v1"
}
] | 2022-10-26 | [
[
"Song",
"Huayang",
""
],
[
"Su",
"Wei",
""
],
[
"Zhang",
"Mengchao",
""
]
] | In this work we revisit the existence of a strong first order electroweak phase transition (SFOEWPT) and recent $m_W$ precision measurement in the Type-I and Type-II 2HDMs. The O(100) GeV new scalars in 2HDMs are favored by SFOEWPT, which is necessary for electroweak baryogenesis, and observed $m_W$ shift as well. % We find that under current constraints, both Type-I and Type-II 2HDM can explain the SFOEWPT, Z-pole, Higgs precision measurements and $m_W$ precision measurement of CDF-II at same time, and all these precision measurements are sensitive to heavy Higgs mass splitting in 2HDM. The allowed regions are $\Delta m_{A/C} \in (-400, 400) GeV, \tanb\in(1,50)$, and $\Delta m_{A/C} \in (-200, 300) GeV, \tanb\in(1,12)$ for Type-I and Type-II 2HDM respectively. Furthermore future lepton collider measurements on Higgs and $Z$ boson properties can explore this scenario in more detail or even rule out it. |
2110.05900 | Miguel Sanchis | Redamy P\'erez-Ramos, Miguel-Angel Sanchis-Lozano, Edward K.
Sarkisyan-Grinbaum | Searching for hidden matter with long-range angular correlations at
$e^+e^-$ colliders | 8 pages, 7 figures | null | 10.1103/PhysRevD.105.053001 | IFIC/21-42, FTUV-21-10-12 | hep-ph hep-ex hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The analysis of azimuthal correlations in multiparticle production can be
useful to uncover the existence of new physics beyond the Standard Model, e.g.,
Hidden Valley, in $e^+e^-$ annihilation at high energies. In this paper, based
on previous theoretical studies and using PYTHIA8 event generator, it is found
that both azimuthal and rapidity long-range correlations are enhanced due to
the presence of a new stage of matter on top of the QCD partonic cascade. Ridge
structures, similar to those observed at the LHC, show up providing a possible
signature of new physics at future $e^+e^-$ colliders.
| [
{
"created": "Tue, 12 Oct 2021 11:20:46 GMT",
"version": "v1"
}
] | 2022-03-23 | [
[
"Pérez-Ramos",
"Redamy",
""
],
[
"Sanchis-Lozano",
"Miguel-Angel",
""
],
[
"Sarkisyan-Grinbaum",
"Edward K.",
""
]
] | The analysis of azimuthal correlations in multiparticle production can be useful to uncover the existence of new physics beyond the Standard Model, e.g., Hidden Valley, in $e^+e^-$ annihilation at high energies. In this paper, based on previous theoretical studies and using PYTHIA8 event generator, it is found that both azimuthal and rapidity long-range correlations are enhanced due to the presence of a new stage of matter on top of the QCD partonic cascade. Ridge structures, similar to those observed at the LHC, show up providing a possible signature of new physics at future $e^+e^-$ colliders. |
hep-ph/9810293 | Cetin Savkli | Cetin Savkli, Franz Gross | Confinement through a relativistic generalization of the linear
interaction | Contributed paper to the Third International Conference On Quark
Confinement, Jefferson Lab, Newport News, Virginia, June 7-12 1998 | null | null | WM-98-104, JLAB-THY-98-35 | hep-ph nucl-th | null | Generalizing a covariant framework previously developed, it is shown that
confinement insures that meson $\to q+\bar{q}$ decay amplitudes vanish when
both quarks are on-shell. Regularization of singularities in a covariant linear
potential associated with nonzero energy transfers (i.e. $q^2=0, q^{\mu}\neq0$)
is improved.
| [
{
"created": "Thu, 8 Oct 1998 15:24:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Savkli",
"Cetin",
""
],
[
"Gross",
"Franz",
""
]
] | Generalizing a covariant framework previously developed, it is shown that confinement insures that meson $\to q+\bar{q}$ decay amplitudes vanish when both quarks are on-shell. Regularization of singularities in a covariant linear potential associated with nonzero energy transfers (i.e. $q^2=0, q^{\mu}\neq0$) is improved. |
hep-ph/0504080 | Gregory Soyez | C. Marquet, G. Soyez | The Balitsky-Kovchegov equation in full momentum space | 11 pages, 7 figures, minor corrections, version appeared in Nucl.
Phys. A | Nucl.Phys. A760 (2005) 208-222 | 10.1016/j.nuclphysa.2005.05.198 | null | hep-ph | null | We analyse the Balitsky-Kovchegov (BK) saturation equation in momentum space
and solve it numerically. We confirm that, in the limit where the transverse
momentum of the incident particle k is much bigger than the momentum transfer
q, the equation admits travelling-wave solutions. We extract the q dependence
of the saturation scale Q_s(Y) and verify that Q_s(Y=cste) scales as
max(q,Q_T), where Q_T is the scale caracterizing the target.
| [
{
"created": "Mon, 11 Apr 2005 15:42:09 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Jun 2006 10:52:30 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Marquet",
"C.",
""
],
[
"Soyez",
"G.",
""
]
] | We analyse the Balitsky-Kovchegov (BK) saturation equation in momentum space and solve it numerically. We confirm that, in the limit where the transverse momentum of the incident particle k is much bigger than the momentum transfer q, the equation admits travelling-wave solutions. We extract the q dependence of the saturation scale Q_s(Y) and verify that Q_s(Y=cste) scales as max(q,Q_T), where Q_T is the scale caracterizing the target. |
1405.4241 | St\'ephane Peign\'e | St\'ephane Peign\'e and Rodion Kolevatov | On the process-dependence of coherent medium-induced gluon radiation | 13 pages, 5 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Considering forward dijet production in the $q\to qg$ partonic process, we
derive the spectrum of accompanying soft gluon radiation induced by
rescatterings in a nuclear target. The spectrum is obtained to logarithmic
accuracy for an arbitrary energy sharing between the final quark and gluon, and
for final transverse momenta as well as momentum imbalance being large as
compared to transverse momentum nuclear broadening. In the case of equal energy
sharing and for approximately back-to-back quark and gluon transverse momenta,
we reproduce a previous result of Liou and Mueller. Interpreting our result, we
conjecture a simple formula for the medium-induced radiation spectrum
associated to hard forward $1 \to n$ processes, which we explicitly check in
the case of the $g \to gg$ process.
| [
{
"created": "Fri, 16 May 2014 16:46:51 GMT",
"version": "v1"
}
] | 2014-05-19 | [
[
"Peigné",
"Stéphane",
""
],
[
"Kolevatov",
"Rodion",
""
]
] | Considering forward dijet production in the $q\to qg$ partonic process, we derive the spectrum of accompanying soft gluon radiation induced by rescatterings in a nuclear target. The spectrum is obtained to logarithmic accuracy for an arbitrary energy sharing between the final quark and gluon, and for final transverse momenta as well as momentum imbalance being large as compared to transverse momentum nuclear broadening. In the case of equal energy sharing and for approximately back-to-back quark and gluon transverse momenta, we reproduce a previous result of Liou and Mueller. Interpreting our result, we conjecture a simple formula for the medium-induced radiation spectrum associated to hard forward $1 \to n$ processes, which we explicitly check in the case of the $g \to gg$ process. |
hep-ph/0012273 | Dr. Dubravko Klabucar | Dubravko Klabucar (Zagreb University), Bojan Bistrovic (M.I.T.) | The anomalous gamma -> pi^+ pi^0 pi^- form factor and the light-quark
mass functions at low momenta | 4 pages, 2 figures, sprocl, invited talk presented by D. Klabucar at
the Mini-Workshop "Few-Quark Problems", Bled, Slovenia, July 8-15, 2000 | Bled Workshops in Physics, Vol. 1, No. 1, p. 41, proceedings of
the Mini-Workshop "Few-Quark Problems", edited by M. Golli, M. Rosina and S.
Sirca; published by DMFA - zaloznistvo, Ljubljana 2000, ISSN 1580-4992. Also
available as electronic edition at http://www-f1.ijs.si/Bled2000/ | null | Zagreb University report ZTF-00/07 | hep-ph nucl-th | null | The gamma -> 3 pi form factor was calculated in a simple-minded constituent
model with a constant quark mass parameter, as well as in the Schwinger-Dyson
approach. The comparison of these and various other theoretical results on this
anomalous process, as well as the scarce already available data (hopefully to
be supplemented by more accurate CEBAF data), seem to favor Schwinger-Dyson
modeling which would yield relatively small low-momentum values of the
constituent (dynamically dressed) quark mass function.
| [
{
"created": "Wed, 20 Dec 2000 16:07:53 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Klabucar",
"Dubravko",
"",
"Zagreb University"
],
[
"Bistrovic",
"Bojan",
"",
"M.I.T."
]
] | The gamma -> 3 pi form factor was calculated in a simple-minded constituent model with a constant quark mass parameter, as well as in the Schwinger-Dyson approach. The comparison of these and various other theoretical results on this anomalous process, as well as the scarce already available data (hopefully to be supplemented by more accurate CEBAF data), seem to favor Schwinger-Dyson modeling which would yield relatively small low-momentum values of the constituent (dynamically dressed) quark mass function. |
hep-ph/0501080 | Steven B. Giddings | Steven B. Giddings | Gravity and strings | Lecture given at 32nd SLAC Summer Institute on Particle Physics (SSI
2004): Natures Greatest Puzzles; Latex, 16 pages, 14 figures | null | null | null | hep-ph gr-qc hep-th | null | This is a broad-brush review of how string theory addresses several important
questions of gravitational physics. The problem of non-renormalizability is
first reviewed, followed by introduction of string theory as an
ultraviolet-finite theory of gravity. String theory's successes also include
predicting both gauge theory and fermions. The difficulty of extra dimensions
becomes a possible virtue, when one notes that these lead to mechanisms to
explain fermion generations, as well as a means to break the large gauge
symmetries of string theory. Finally, a long standing problem of string theory,
that of fixing the size and shape of the extra dimensions, has recently been
addressed and may shed light on the origin of the cosmological constant, the
ultimate fate of our universe, as well as the question of why gravity_is_ so
weak.
| [
{
"created": "Tue, 11 Jan 2005 01:25:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Giddings",
"Steven B.",
""
]
] | This is a broad-brush review of how string theory addresses several important questions of gravitational physics. The problem of non-renormalizability is first reviewed, followed by introduction of string theory as an ultraviolet-finite theory of gravity. String theory's successes also include predicting both gauge theory and fermions. The difficulty of extra dimensions becomes a possible virtue, when one notes that these lead to mechanisms to explain fermion generations, as well as a means to break the large gauge symmetries of string theory. Finally, a long standing problem of string theory, that of fixing the size and shape of the extra dimensions, has recently been addressed and may shed light on the origin of the cosmological constant, the ultimate fate of our universe, as well as the question of why gravity_is_ so weak. |
1807.07026 | Dirk Dubbers | Dirk Dubbers | Comment on "Neutron Lifetime and Axial Coupling Constant" by A.
Czarnecki et al | 1 page | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I give a comment on arXiv:1802.01804v3 [hep-ph]
| [
{
"created": "Tue, 17 Jul 2018 10:33:08 GMT",
"version": "v1"
}
] | 2018-07-19 | [
[
"Dubbers",
"Dirk",
""
]
] | I give a comment on arXiv:1802.01804v3 [hep-ph] |
2203.09863 | D. Indumathi | R. Thiru Senthil (HBNI, Mumbai, IMSc, Chennai), D. Indumathi (HBNI,
Mumbai, IMSc, Chennai), Prashant Shukla (HBNI, Mumbai, BARC, Mumbai) | A simulation study of tau neutrino events at the ICAL detector in INO | 27 pages, 13 figures, latex document, revised to include more details
on the effect of fluctuations, dependence on exposure time, and inclusion of
a discussion of hadron energy systematics. Version accepted in PRD | Phys. Rev. D 106, 093004, 2022 | 10.1103/PhysRevD.106.093004 | IMSc/2022/01/01 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We present the first detailed simulation study of tau neutrino-induced
charged current (CC) events from atmospheric neutrino interactions in the Iron
Calorimeter (ICAL) detector at the proposed India-based Neutrino Observatory
(INO) laboratory. Since the intrinsic atmospheric neutrino flux at few to 10s
of GeV energy comprises only electron and muon neutrinos (and anti-neutrinos)
with negligible tau neutrino component, any signature of atmospheric tau
neutrinos is a signal for neutrino oscillations. We study the tau leptons
produced through these CC interactions via their hadronic decay. These events
appear as an excess over the neutral current (NC) background where hadrons are
the only observable component. We find that the presence of tau neutrinos in
the atmospheric neutrino flux can be demonstrated to nearly $4\sigma$
confidence with 10 years data; in addition, these events are sensitive to the
neutrino oscillation parameters, $\sin^2\theta_{23}$ and $\vert \Delta m_{31}^2
\vert$ (or $\vert \Delta m_{32}^2 \vert$), in the 2--3 sector. Finally, we show
that combining these events with the standard muon analysis which is the core
goal of ICAL further improves the precision with which these parameters,
especially the octant of $\theta_{23}$, can be measured.
| [
{
"created": "Fri, 18 Mar 2022 11:05:43 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Nov 2022 06:07:11 GMT",
"version": "v2"
}
] | 2022-11-21 | [
[
"Senthil",
"R. Thiru",
"",
"HBNI, Mumbai, IMSc, Chennai"
],
[
"Indumathi",
"D.",
"",
"HBNI,\n Mumbai, IMSc, Chennai"
],
[
"Shukla",
"Prashant",
"",
"HBNI, Mumbai, BARC, Mumbai"
]
] | We present the first detailed simulation study of tau neutrino-induced charged current (CC) events from atmospheric neutrino interactions in the Iron Calorimeter (ICAL) detector at the proposed India-based Neutrino Observatory (INO) laboratory. Since the intrinsic atmospheric neutrino flux at few to 10s of GeV energy comprises only electron and muon neutrinos (and anti-neutrinos) with negligible tau neutrino component, any signature of atmospheric tau neutrinos is a signal for neutrino oscillations. We study the tau leptons produced through these CC interactions via their hadronic decay. These events appear as an excess over the neutral current (NC) background where hadrons are the only observable component. We find that the presence of tau neutrinos in the atmospheric neutrino flux can be demonstrated to nearly $4\sigma$ confidence with 10 years data; in addition, these events are sensitive to the neutrino oscillation parameters, $\sin^2\theta_{23}$ and $\vert \Delta m_{31}^2 \vert$ (or $\vert \Delta m_{32}^2 \vert$), in the 2--3 sector. Finally, we show that combining these events with the standard muon analysis which is the core goal of ICAL further improves the precision with which these parameters, especially the octant of $\theta_{23}$, can be measured. |
1902.05285 | Manu Kurian | Samapan Bhadury, Manu Kurian, Vinod Chandra and Amaresh Jaiswal | First order dissipative hydrodynamics and viscous corrections to the
entropy four-current from an effective covariant kinetic theory | 15 pages, 11 figures, version accepted for publication in Journal of
Physics G | J. Phys. G 47 (2020) 8, 085108 | 10.1088/1361-6471/ab907b | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The first order hydrodynamic evolution equations for the shear stress tensor,
the bulk viscous pressure and the charge current have been studied for a system
of quarks and gluons, with a non-vanishing quark chemical potential and finite
quark mass. The first order transport coefficients have been obtained by
solving an effective Boltzmann equation for the grand-canonical ensemble of
quasiquarks and quasigluons. We adopted temperature dependent effective
fugacity for the quasiparticles to encode the hot QCD medium effects. The
non-trivial energy dispersion of the quasiparticles induces mean field
contributions to the transport coefficients whose origin could be directly
related to the realization of conservation laws from the effective kinetic
theory. Both the QCD equation of state and chemical potential are seen to have
a significant impact on the quark-gluon plasma evolution. The shear and bulk
viscous corrections to the entropy-four current have been investigated in the
framework of the effective kinetic theory. The effect of viscous corrections to
the entropy density have been quantified in the case of one dimensional
boost-invariant expansion of the system. Further, the first order viscous
corrections to the time evolution of temperature along with the description of
pressure anisotropy and Reynolds number of the system have been explored for
the longitudinal boost-invariant expansion.volution of temperature along with
the description of pressure anisotropy of the system have also been explored.
| [
{
"created": "Thu, 14 Feb 2019 09:59:00 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Jul 2019 12:15:58 GMT",
"version": "v2"
},
{
"created": "Fri, 1 May 2020 18:12:17 GMT",
"version": "v3"
}
] | 2020-07-16 | [
[
"Bhadury",
"Samapan",
""
],
[
"Kurian",
"Manu",
""
],
[
"Chandra",
"Vinod",
""
],
[
"Jaiswal",
"Amaresh",
""
]
] | The first order hydrodynamic evolution equations for the shear stress tensor, the bulk viscous pressure and the charge current have been studied for a system of quarks and gluons, with a non-vanishing quark chemical potential and finite quark mass. The first order transport coefficients have been obtained by solving an effective Boltzmann equation for the grand-canonical ensemble of quasiquarks and quasigluons. We adopted temperature dependent effective fugacity for the quasiparticles to encode the hot QCD medium effects. The non-trivial energy dispersion of the quasiparticles induces mean field contributions to the transport coefficients whose origin could be directly related to the realization of conservation laws from the effective kinetic theory. Both the QCD equation of state and chemical potential are seen to have a significant impact on the quark-gluon plasma evolution. The shear and bulk viscous corrections to the entropy-four current have been investigated in the framework of the effective kinetic theory. The effect of viscous corrections to the entropy density have been quantified in the case of one dimensional boost-invariant expansion of the system. Further, the first order viscous corrections to the time evolution of temperature along with the description of pressure anisotropy and Reynolds number of the system have been explored for the longitudinal boost-invariant expansion.volution of temperature along with the description of pressure anisotropy of the system have also been explored. |
0709.1816 | Timothy Burns | T.J. Burns, F.E. Close and C.E. Thomas | Dynamics of hadron strong production and decay | 13 pages; journal version | Phys.Rev.D77:034008,2008 | 10.1103/PhysRevD.77.034008 | null | hep-ph | null | We generalize results of lattice QCD to determine the spin-dependent
symmetries and factorization properties of meson production in OZI allowed
processes. This explains some conjectures previously made in the literature
about axial meson decays and gives predictions for exclusive decays of vector
charmonia, including ways of establishing the structure of Y(4260) and Y(4325)
from their S-wave decays. Factorization gives a selection rule which forbids
$e^+e^- \to D^* D_2$ near threshold with the tensor meson in helicity 2. The
relations among amplitudes for double charmonia production $\e^+e^-\to
\psi\chi_{0,1,2}$ are expected to differ from the analagous relations among
light flavour production such as $\e^+e^-\to \omega f_{0,1,2}$.
| [
{
"created": "Wed, 12 Sep 2007 11:54:53 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Apr 2008 05:36:49 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Burns",
"T. J.",
""
],
[
"Close",
"F. E.",
""
],
[
"Thomas",
"C. E.",
""
]
] | We generalize results of lattice QCD to determine the spin-dependent symmetries and factorization properties of meson production in OZI allowed processes. This explains some conjectures previously made in the literature about axial meson decays and gives predictions for exclusive decays of vector charmonia, including ways of establishing the structure of Y(4260) and Y(4325) from their S-wave decays. Factorization gives a selection rule which forbids $e^+e^- \to D^* D_2$ near threshold with the tensor meson in helicity 2. The relations among amplitudes for double charmonia production $\e^+e^-\to \psi\chi_{0,1,2}$ are expected to differ from the analagous relations among light flavour production such as $\e^+e^-\to \omega f_{0,1,2}$. |
1606.07082 | Aielet Efrati | Aielet Efrati, Jernej F. Kamenik and Yosef Nir | The phenomenology of the di-photon excess and $h\to\tau\mu$ within 2HDM | 10 pages, 6 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The diphoton excess around $m_S=750$ GeV observed at ATLAS and CMS can be
interpreted as coming from $S=H$ and $A$, the neutral components of a second
Higgs doublet. If so, then the consistency of the light Higgs decays with the
Standard Model predictions provides upper bounds on the rates of $S\to VV, hZ,
hh$ decays. On the other hand, if $h\to\tau\mu$ decay is established, then a
lower bound on the rate of $S\to\tau\mu$ decay arises. Requiring that
$\Gamma_S\lesssim45$ GeV gives both an upper and a lower bound on the rotation
angle from the Higgs basis $(\Phi_v,\Phi_A)$ to the mass basis
$(\Phi_h,\Phi_H)$. The charged scalar, with $m_{H^\pm}\simeq750$ GeV, is
produced in association with a top quark, and can decay to $\mu^\pm\nu$,
$\tau^\pm\nu$, $tb$ and $W^\pm h$
| [
{
"created": "Wed, 22 Jun 2016 20:08:32 GMT",
"version": "v1"
}
] | 2016-06-24 | [
[
"Efrati",
"Aielet",
""
],
[
"Kamenik",
"Jernej F.",
""
],
[
"Nir",
"Yosef",
""
]
] | The diphoton excess around $m_S=750$ GeV observed at ATLAS and CMS can be interpreted as coming from $S=H$ and $A$, the neutral components of a second Higgs doublet. If so, then the consistency of the light Higgs decays with the Standard Model predictions provides upper bounds on the rates of $S\to VV, hZ, hh$ decays. On the other hand, if $h\to\tau\mu$ decay is established, then a lower bound on the rate of $S\to\tau\mu$ decay arises. Requiring that $\Gamma_S\lesssim45$ GeV gives both an upper and a lower bound on the rotation angle from the Higgs basis $(\Phi_v,\Phi_A)$ to the mass basis $(\Phi_h,\Phi_H)$. The charged scalar, with $m_{H^\pm}\simeq750$ GeV, is produced in association with a top quark, and can decay to $\mu^\pm\nu$, $\tau^\pm\nu$, $tb$ and $W^\pm h$ |
1409.2939 | Sibo Zheng | Sibo Zheng | On Dark Matter Selected High-Scale Supersymmetry | 16 pages, minor changes, journal version | JHEP 1503 (2015) 062 | 10.1007/JHEP03(2015)062 | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | The prediction for the Higgs mass in the dark matter selected high-scale SUSY
is explored. We show the bounds on SUSY-breaking scale in models of SM
$+\tilde{w}$ and SM $+\tilde{h}/\tilde{s}$ due to the observed Higgs mass at
the LHC. We propose that effective theory below scale $\tilde{m}$ described by
SM $+\tilde{w}$ is possibly realized in gauge mediation with multiple spurion
fields that exhibit significant mass hierarchy, and that by SM
$+\tilde{h}/\tilde{s}$ can be realized with direct singlet-messenger-messenger
coupling for singlet Yukawa coupling
$\lambda\sim(v/\tilde{m})^{1/2}g_{\text{SM}}$. Finally, the constraint on
high-scale SUSY is investigated in the light of inflation physics if these two
subjects are directly related.
| [
{
"created": "Wed, 10 Sep 2014 02:38:00 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Jan 2015 01:40:08 GMT",
"version": "v2"
},
{
"created": "Tue, 17 Feb 2015 00:58:16 GMT",
"version": "v3"
}
] | 2015-03-13 | [
[
"Zheng",
"Sibo",
""
]
] | The prediction for the Higgs mass in the dark matter selected high-scale SUSY is explored. We show the bounds on SUSY-breaking scale in models of SM $+\tilde{w}$ and SM $+\tilde{h}/\tilde{s}$ due to the observed Higgs mass at the LHC. We propose that effective theory below scale $\tilde{m}$ described by SM $+\tilde{w}$ is possibly realized in gauge mediation with multiple spurion fields that exhibit significant mass hierarchy, and that by SM $+\tilde{h}/\tilde{s}$ can be realized with direct singlet-messenger-messenger coupling for singlet Yukawa coupling $\lambda\sim(v/\tilde{m})^{1/2}g_{\text{SM}}$. Finally, the constraint on high-scale SUSY is investigated in the light of inflation physics if these two subjects are directly related. |
1505.06272 | Emanuele Mereghetti | E. Mereghetti (Los Alamos) and U. van Kolck (Orsay, IPN & Arizona U.) | Effective Field Theory and Time-Reversal Violation in Light Nuclei | 35 pages. Accepted for publication in Ann. Rev. Nucl. Part. Sci. 65
(2015) | null | null | LAUR-15-23119 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Thanks to the unnaturally small value of the QCD vacuum angle $\bar\theta <
10^{-10}$, time-reversal ($T$) violation offers a window into physics beyond
the Standard Model (SM) of particle physics. We review the
effective-field-theory framework that establishes a clean connection between
$T$-violating mechanisms, which can be represented by higher-dimensional
operators involving SM fields and symmetries, and hadronic interactions, which
allow for controlled calculations of low-energy observables involving strong
interactions. The chiral properties of $T$-violating mechanisms leads to a
pattern that should be identifiable in measurements of the electric dipole
moments of the nucleon and light nuclei.
| [
{
"created": "Sat, 23 May 2015 04:04:56 GMT",
"version": "v1"
}
] | 2015-05-26 | [
[
"Mereghetti",
"E.",
"",
"Los Alamos"
],
[
"van Kolck",
"U.",
"",
"Orsay, IPN & Arizona U."
]
] | Thanks to the unnaturally small value of the QCD vacuum angle $\bar\theta < 10^{-10}$, time-reversal ($T$) violation offers a window into physics beyond the Standard Model (SM) of particle physics. We review the effective-field-theory framework that establishes a clean connection between $T$-violating mechanisms, which can be represented by higher-dimensional operators involving SM fields and symmetries, and hadronic interactions, which allow for controlled calculations of low-energy observables involving strong interactions. The chiral properties of $T$-violating mechanisms leads to a pattern that should be identifiable in measurements of the electric dipole moments of the nucleon and light nuclei. |
hep-ph/9411297 | Ken-ichi Hikasa | T. Asaka and Ken-ichi Hikasa | Four-fermion decay of Higgs bosons | 12 pages, 4 figures, uses an obsolete version of phyzzx with
modification (included in the file). Missing preprint no. added | Phys.Lett.B345:36-41,1995 | 10.1016/0370-2693(94)01599-8 | TU-471 | hep-ph | null | We calculate four-fermion decays of a Higgs boson via $WW$ and/or $ZZ$
intermediate states for Higgs masses below $m_W$. We examine models with a
doubly-charged Higgs boson $H^{++}$ and show that the four-fermion decay is the
dominant mode for a wide range of parameter space. Existing searches for
$H^{++}$ in $Z$ decays have not looked for this mode. We also derive
four-fermion decay rate for a neutral Higgs boson.
| [
{
"created": "Tue, 15 Nov 1994 06:36:13 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Nov 1994 09:17:57 GMT",
"version": "v2"
}
] | 2009-09-25 | [
[
"Asaka",
"T.",
""
],
[
"Hikasa",
"Ken-ichi",
""
]
] | We calculate four-fermion decays of a Higgs boson via $WW$ and/or $ZZ$ intermediate states for Higgs masses below $m_W$. We examine models with a doubly-charged Higgs boson $H^{++}$ and show that the four-fermion decay is the dominant mode for a wide range of parameter space. Existing searches for $H^{++}$ in $Z$ decays have not looked for this mode. We also derive four-fermion decay rate for a neutral Higgs boson. |
0909.4038 | Samuel Wallon | I.V.Anikin, D.Yu.Ivanov, B.Pire, L.Szymanowski, S.Wallon | QCD factorization beyond leading twist in exclusive processes:
rhoT-meson production | 5 pages, Proceedings of EPS conference, Krakow, 16-22 July 2009 | PoS EPS-HEP2009:070,2009 | null | LPT 09-73, CPHT-PC091.0909 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Exclusive processes in hard electroproduction is one of the best place for
understanding the factorization properties of QCD. The HERA experiment recently
provided precise data for rho electroproduction, including all spin density
matrix elements. From QCD, it is expected that such a process should factorize
between a hard (calculable) coefficient function, and hadronic (p and rho)
matrix elements. Such a factorization is up to now only proven for a
longitudinaly polarized rho. Within the kt-factorization approach (valid at
large s_{gamma* p}), we evaluate the impact factor of the transition gamma* ->
rhoT taking into account the twist 3 contributions. We show that a gauge
invariant expression is obtained with the help of QCD equations of motion. More
generally, relying on these equations and on the invariance under rotation on
the light-cone of the factorized amplitude, the non-perturbative Distribution
Amplitudes can be reduced to a minimal set. This opens the way to a consistent
treatment of factorization for exclusive processes with a transversally
polarized vector meson. We prove the equivalence of two proposed
parametrizations of the rhoT distribution amplitudes.
| [
{
"created": "Tue, 22 Sep 2009 16:48:34 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Sep 2009 21:45:24 GMT",
"version": "v2"
},
{
"created": "Wed, 3 Feb 2010 09:50:03 GMT",
"version": "v3"
}
] | 2014-11-20 | [
[
"Anikin",
"I. V.",
""
],
[
"Ivanov",
"D. Yu.",
""
],
[
"Pire",
"B.",
""
],
[
"Szymanowski",
"L.",
""
],
[
"Wallon",
"S.",
""
]
] | Exclusive processes in hard electroproduction is one of the best place for understanding the factorization properties of QCD. The HERA experiment recently provided precise data for rho electroproduction, including all spin density matrix elements. From QCD, it is expected that such a process should factorize between a hard (calculable) coefficient function, and hadronic (p and rho) matrix elements. Such a factorization is up to now only proven for a longitudinaly polarized rho. Within the kt-factorization approach (valid at large s_{gamma* p}), we evaluate the impact factor of the transition gamma* -> rhoT taking into account the twist 3 contributions. We show that a gauge invariant expression is obtained with the help of QCD equations of motion. More generally, relying on these equations and on the invariance under rotation on the light-cone of the factorized amplitude, the non-perturbative Distribution Amplitudes can be reduced to a minimal set. This opens the way to a consistent treatment of factorization for exclusive processes with a transversally polarized vector meson. We prove the equivalence of two proposed parametrizations of the rhoT distribution amplitudes. |
1510.02697 | Ryusuke Jinno | Ryusuke Jinno, Kazunori Nakayama and Masahiro Takimoto | Gravitational waves from the first order phase transition of the Higgs
field at high energy scales | 10 pages, 13 figures | Phys. Rev. D 93, 045024 (2016) | 10.1103/PhysRevD.93.045024 | UT-15-39 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a wide class of new physics models, there exist scalar fields that obtain
vacuum expectation values of high energy scales. We study the possibility that
the standard model Higgs field has experienced first order phase transition at
the high energy scale due to the couplings with these scalar fields. We
estimate the amount of gravitational waves produced by the phase transition,
and discuss observational consequences.
| [
{
"created": "Fri, 9 Oct 2015 15:10:00 GMT",
"version": "v1"
},
{
"created": "Fri, 20 May 2016 12:48:33 GMT",
"version": "v2"
}
] | 2016-05-23 | [
[
"Jinno",
"Ryusuke",
""
],
[
"Nakayama",
"Kazunori",
""
],
[
"Takimoto",
"Masahiro",
""
]
] | In a wide class of new physics models, there exist scalar fields that obtain vacuum expectation values of high energy scales. We study the possibility that the standard model Higgs field has experienced first order phase transition at the high energy scale due to the couplings with these scalar fields. We estimate the amount of gravitational waves produced by the phase transition, and discuss observational consequences. |
hep-ph/0403184 | Michal Praszalowicz | Maciej A. Nowak, Michal Praszalowicz, Mariusz Sadzikowski and Joanna
Wasiluk | Chiral doublers of heavy-light baryons | 10 pages, in v2 some typos corrected, references added | Phys.Rev. D70 (2004) 031503 | 10.1103/PhysRevD.70.031503 | TPJU-4/2004, BNL-NT-04/10 | hep-ph | null | We discuss the consequences of the chiral doubling scenario for baryons built
of heavy and light quarks. In particular, we use the soliton description for
baryons, demonstrating why each heavy-light baryon should be accompanied by the
opposite parity partner. Our argumentation holds both for ordinary baryons and
for exotic heavy pentaquarks which are required by the symmetries of QCD to
appear in parity doublets, seperated by the mass shift of the chiral origin.
Interpreting the recently observed by BaBaR, CLEO and Belle charmed mesons with
assignment $(0^+,1^+)$ as the chiral partners of known $D$ and $D^*$ mesons,
allows us to estimate the parameters of the mesonic effective lagrangian, and
in consequence, estimate the masses of ground states and excited states of both
parities. In particular, we interpret the state recently reported by the H1
experiment at HERA as a chiral partner $\tilde{\Theta}_c^0(3099)$ of yet
undiscovered ground state pentaquark $\Theta_c^0(2700)$.
| [
{
"created": "Tue, 16 Mar 2004 19:29:20 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Mar 2004 18:03:29 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Nowak",
"Maciej A.",
""
],
[
"Praszalowicz",
"Michal",
""
],
[
"Sadzikowski",
"Mariusz",
""
],
[
"Wasiluk",
"Joanna",
""
]
] | We discuss the consequences of the chiral doubling scenario for baryons built of heavy and light quarks. In particular, we use the soliton description for baryons, demonstrating why each heavy-light baryon should be accompanied by the opposite parity partner. Our argumentation holds both for ordinary baryons and for exotic heavy pentaquarks which are required by the symmetries of QCD to appear in parity doublets, seperated by the mass shift of the chiral origin. Interpreting the recently observed by BaBaR, CLEO and Belle charmed mesons with assignment $(0^+,1^+)$ as the chiral partners of known $D$ and $D^*$ mesons, allows us to estimate the parameters of the mesonic effective lagrangian, and in consequence, estimate the masses of ground states and excited states of both parities. In particular, we interpret the state recently reported by the H1 experiment at HERA as a chiral partner $\tilde{\Theta}_c^0(3099)$ of yet undiscovered ground state pentaquark $\Theta_c^0(2700)$. |
hep-ph/0512203 | Vladimir Miransky | E.V. Gorbar, Junji Jia, V.A. Miransky | Vortices in gauge models at finite density with vector condensates | Revtex, 13 pages, 4 figures, v2: to match PRD version | Phys.Rev. D73 (2006) 045001 | 10.1103/PhysRevD.73.045001 | UWO-TH-05/18 | hep-ph cond-mat.supr-con hep-th | null | There exists a class of gauge models incorporating a finite density of matter
in which the Higgs mechanism is provided by condensates of gauge (or gauge and
scalar) fields, i.e., there are vector condensates in this case. We describe
vortex solutions in the simplest model in this class, the gauged $SU(2)\times
U(1)_Y$ $\sigma$-model with the chemical potential for hypercharge $Y$, in
which the gauge symmetry is completely broken. It is shown that there are three
types of topologically stable vortices in the model, connected either with
photon field or hypercharge gauge field, or with both of them. Explicit vortex
solutions are numerically found and their energy per unit length are
calculated. The relevance of these solutions for the gluonic phase in the dense
two-flavor QCD is discussed.
| [
{
"created": "Thu, 15 Dec 2005 18:47:15 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Feb 2006 20:53:51 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Gorbar",
"E. V.",
""
],
[
"Jia",
"Junji",
""
],
[
"Miransky",
"V. A.",
""
]
] | There exists a class of gauge models incorporating a finite density of matter in which the Higgs mechanism is provided by condensates of gauge (or gauge and scalar) fields, i.e., there are vector condensates in this case. We describe vortex solutions in the simplest model in this class, the gauged $SU(2)\times U(1)_Y$ $\sigma$-model with the chemical potential for hypercharge $Y$, in which the gauge symmetry is completely broken. It is shown that there are three types of topologically stable vortices in the model, connected either with photon field or hypercharge gauge field, or with both of them. Explicit vortex solutions are numerically found and their energy per unit length are calculated. The relevance of these solutions for the gluonic phase in the dense two-flavor QCD is discussed. |
2207.10350 | J\'er\'emie Quarroz | Christian Br{\o}nnum-Hansen, J\'er\'emie Quarroz, Chiara
Signorile-Signorile, Chen-Yu Wang | Non-factorisable contributions to $t$-channel single-top production at
the LHC and FCC | 11 pages, 4 figures, Contribution to the proceedings of Loops and
Legs in Quantum Field Theory (LL2022), Ettal, Germany | null | null | TTP22-050, P3H-22-080 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Single top quark is mainly produced through the $t$-channel W boson exchange
$q + b \rightarrow q' + t$ at LHC. This process probes Wtb vertex directly and
can be used to measure the CKM matrix element $V_{tb}$ or to constrain the
bottom quark PDF. The non-factorisable contributions are the last missing piece
of the NNLO corrections. In these proceedings, we discuss in a first part the
ostensible importance of such corrections and the obtention of the different
relevant amplitudes. In the second part, recently published results at the
energy of the LHC are compared to new results for proton-proton collision at
$100 \: {\rm TeV}$, the energy of the FCC.
| [
{
"created": "Thu, 21 Jul 2022 08:08:43 GMT",
"version": "v1"
}
] | 2022-07-22 | [
[
"Brønnum-Hansen",
"Christian",
""
],
[
"Quarroz",
"Jérémie",
""
],
[
"Signorile-Signorile",
"Chiara",
""
],
[
"Wang",
"Chen-Yu",
""
]
] | Single top quark is mainly produced through the $t$-channel W boson exchange $q + b \rightarrow q' + t$ at LHC. This process probes Wtb vertex directly and can be used to measure the CKM matrix element $V_{tb}$ or to constrain the bottom quark PDF. The non-factorisable contributions are the last missing piece of the NNLO corrections. In these proceedings, we discuss in a first part the ostensible importance of such corrections and the obtention of the different relevant amplitudes. In the second part, recently published results at the energy of the LHC are compared to new results for proton-proton collision at $100 \: {\rm TeV}$, the energy of the FCC. |
1706.06966 | Peter Vastag | Ehsan Ebadati, Hugo Reinhardt and Peter Vastag | Chiral symmetry restoration at finite temperature within the Hamiltonian
approach to QCD in Coulomb gauge | Manuscript has been superseded by a new submission with new
techniques and a complete overhaul on a computational and formal level,
including a change in the author list | Phys. Rev. D 98, 034012 (2018) | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The chiral phase transition of the quark sector of QCD is investigated within
the Hamiltonian approach in Coulomb gauge. Finite temperatures $T$ are
introduced by compactifying one spatial dimension, which makes all
thermodynamical quantities accessible from the ground state on the spatial
manifold $\mathbb{R}^2 \times S^1(1/T)$. In the limit of a vanishing
quark-gluon coupling, the equations of motion of the quark sector are solved
numerically and the chiral quark condensate is evaluated and compared to the
results of the usual canonical approach to finite-temperature Hamiltonian QCD
based on the density operator of the grand canonical ensemble. For zero bare
quark masses, we find a second-order chiral phase transition with a critical
temperature of about $107 \, \mathrm{MeV}$.
| [
{
"created": "Wed, 21 Jun 2017 15:43:03 GMT",
"version": "v1"
},
{
"created": "Tue, 22 May 2018 15:48:13 GMT",
"version": "v2"
}
] | 2018-10-19 | [
[
"Ebadati",
"Ehsan",
""
],
[
"Reinhardt",
"Hugo",
""
],
[
"Vastag",
"Peter",
""
]
] | The chiral phase transition of the quark sector of QCD is investigated within the Hamiltonian approach in Coulomb gauge. Finite temperatures $T$ are introduced by compactifying one spatial dimension, which makes all thermodynamical quantities accessible from the ground state on the spatial manifold $\mathbb{R}^2 \times S^1(1/T)$. In the limit of a vanishing quark-gluon coupling, the equations of motion of the quark sector are solved numerically and the chiral quark condensate is evaluated and compared to the results of the usual canonical approach to finite-temperature Hamiltonian QCD based on the density operator of the grand canonical ensemble. For zero bare quark masses, we find a second-order chiral phase transition with a critical temperature of about $107 \, \mathrm{MeV}$. |
hep-ph/0212160 | Pawel Jankowski | F.Cornet (Granada U.), P.Jankowski (Warsaw U.), M.Krawczyk (Warsaw U.
& CERN), A.Lorca (Granada U. & DESY Zeuthen) | A New 5-Flavour LO Analysis and Parametrization of Parton Distributions
in the Real Photon | 43 pages, RevTeX4 using axodraw style, 3 tex and 12 postscript
figures, version submitted to Phys. Rev. D, small text changes, one reference
added, FORTRAN program available at http://www.fuw.edu.pl/~pjank/param.html
and at http://www-zeuthen.desy.de/~alorca/id4.html | Phys.Rev.D68:014010,2003 | 10.1103/PhysRevD.68.014010 | CERN-TH/2002-362, IFT-22/2002, UG-FT-138/02, CAFPE-8/02, DESY 02-118 | hep-ph | null | New, radiatively generated, LO quark (u,d,s,c,b) and gluon densities in a
real, unpolarized photon are presented. We perform a global 3-parameter fit,
based on LO DGLAP evolution equations, to all available data for the structure
function F2^gamma(x,Q^2). We adopt a new theoretical approach called ACOT(chi),
originally introduced for the proton, to deal with the heavy-quark thresholds.
This defines our basic model (CJKL model), which gives a very good description
of the experimental data on F2^gamma(x,Q^2), for both Q^2 and x dependences.
For comparison we perform a standard fit using the Fixed Flavour-Number Scheme
(FFNS_CJKL model), updated with respect to the previous fits of this type. We
show the superiority of the CJKL fit over the FFNS_CJKL one and other LO fits
to the F2^gamma(x,Q^2) data. The CJKL model gives also the best description of
the LEP data on the Q^2 dependence of the F2^gamma, averaged over various
x-regions, and the F_2,c^gamma, which were not used directly in the fit.
Finally, a simple analytic parametrization of the resulting parton densities
obtained with the CJKL model is given.
| [
{
"created": "Wed, 11 Dec 2002 16:54:13 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Feb 2003 19:58:09 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Cornet",
"F.",
"",
"Granada U."
],
[
"Jankowski",
"P.",
"",
"Warsaw U."
],
[
"Krawczyk",
"M.",
"",
"Warsaw U.\n & CERN"
],
[
"Lorca",
"A.",
"",
"Granada U. & DESY Zeuthen"
]
] | New, radiatively generated, LO quark (u,d,s,c,b) and gluon densities in a real, unpolarized photon are presented. We perform a global 3-parameter fit, based on LO DGLAP evolution equations, to all available data for the structure function F2^gamma(x,Q^2). We adopt a new theoretical approach called ACOT(chi), originally introduced for the proton, to deal with the heavy-quark thresholds. This defines our basic model (CJKL model), which gives a very good description of the experimental data on F2^gamma(x,Q^2), for both Q^2 and x dependences. For comparison we perform a standard fit using the Fixed Flavour-Number Scheme (FFNS_CJKL model), updated with respect to the previous fits of this type. We show the superiority of the CJKL fit over the FFNS_CJKL one and other LO fits to the F2^gamma(x,Q^2) data. The CJKL model gives also the best description of the LEP data on the Q^2 dependence of the F2^gamma, averaged over various x-regions, and the F_2,c^gamma, which were not used directly in the fit. Finally, a simple analytic parametrization of the resulting parton densities obtained with the CJKL model is given. |
1912.06661 | Mathias Pierre | Julia Gehrlein and Mathias Pierre | A testable hidden-sector model for Dark Matter and neutrino masses | 38 pages, 5 figures. v2: Matches the published version, typos fixed,
references added | JHEP02 (2020) 068 | 10.1007/JHEP02(2020)068 | IFT-UAM/CSIC-19-167 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a minimal extension of the Standard Model with a hidden sector
charged under a dark local $U(1)'$ gauge group, accounting simultaneously for
light neutrino masses and the observed Dark Matter relic abundance. The model
contains two copies of right-handed neutrinos which give rise to light
neutrino-masses via an extended seesaw mechanism. The presence of a stable
Dark-Matter candidate and a massless state naturally arise by requiring the
simplest anomaly-free particle content without introducing any extra
symmetries. We investigate the phenomenology of the hidden sector considering
the $U(1)'$ breaking scale of the order of the electroweak scale. Confronting
the thermal history of this hidden-sector model with existing and future
constraints from collider, direct and indirect detection experiments provides
various possibilities of probing the model in complementary ways as every
particle of the dark sector plays a specific cosmological role. Across the
identified viable parameter space, a large region predicts a sizable
contribution to the effective relativistic degrees-of-freedom in the early
Universe that allows to alleviate the recently reported tension between late
and early measurements of the Hubble constant.
| [
{
"created": "Fri, 13 Dec 2019 19:00:07 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Feb 2020 18:22:17 GMT",
"version": "v2"
}
] | 2020-02-14 | [
[
"Gehrlein",
"Julia",
""
],
[
"Pierre",
"Mathias",
""
]
] | We consider a minimal extension of the Standard Model with a hidden sector charged under a dark local $U(1)'$ gauge group, accounting simultaneously for light neutrino masses and the observed Dark Matter relic abundance. The model contains two copies of right-handed neutrinos which give rise to light neutrino-masses via an extended seesaw mechanism. The presence of a stable Dark-Matter candidate and a massless state naturally arise by requiring the simplest anomaly-free particle content without introducing any extra symmetries. We investigate the phenomenology of the hidden sector considering the $U(1)'$ breaking scale of the order of the electroweak scale. Confronting the thermal history of this hidden-sector model with existing and future constraints from collider, direct and indirect detection experiments provides various possibilities of probing the model in complementary ways as every particle of the dark sector plays a specific cosmological role. Across the identified viable parameter space, a large region predicts a sizable contribution to the effective relativistic degrees-of-freedom in the early Universe that allows to alleviate the recently reported tension between late and early measurements of the Hubble constant. |
hep-ph/9708407 | Ernest Ma | E. Keith and Ernest Ma (UC Riverside) | Revelations of the U(1)-Extended Supersymmetric Standard Model | 6 pages, no figure (Talk given by E. Ma at BSM V) | null | 10.1063/1.54486 | UCRHEP-T189 (June 1997) | hep-ph | null | If an extra supersymmetric U(1) gauge factor exists at the TeV energy scale,
which is then broken together with the supersymmetry, there will be several
interesting and important phenomenological consequences, not only at the TeV
scale, but also at the 100 GeV scale. For one, the generic two-doublet Higgs
structure will involve 3 additional parameters beyond that of the Minimal
Supersymmetric Standard Model (MSSM), thereby raising the upper bound on the
mass of the lighter of the two neutral Higgs scalars. For another, the
supersymmetric scalar quarks and leptons receive new contributions to their
masses from the spontaneous breaking of this extra U(1). Assuming a
grand-unified E_6 gauge symmetry and universal soft supersymmetry-breaking
terms at the grand-unification energy scale, we find solutions relating the
U(1) breaking scale and the ratio of the vacuum expectation values of the two
electroweak Higgs doublets.
| [
{
"created": "Tue, 19 Aug 1997 19:34:34 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Keith",
"E.",
"",
"UC Riverside"
],
[
"Ma",
"Ernest",
"",
"UC Riverside"
]
] | If an extra supersymmetric U(1) gauge factor exists at the TeV energy scale, which is then broken together with the supersymmetry, there will be several interesting and important phenomenological consequences, not only at the TeV scale, but also at the 100 GeV scale. For one, the generic two-doublet Higgs structure will involve 3 additional parameters beyond that of the Minimal Supersymmetric Standard Model (MSSM), thereby raising the upper bound on the mass of the lighter of the two neutral Higgs scalars. For another, the supersymmetric scalar quarks and leptons receive new contributions to their masses from the spontaneous breaking of this extra U(1). Assuming a grand-unified E_6 gauge symmetry and universal soft supersymmetry-breaking terms at the grand-unification energy scale, we find solutions relating the U(1) breaking scale and the ratio of the vacuum expectation values of the two electroweak Higgs doublets. |
hep-ph/9304310 | Carsten Grosse-Knetter | Carsten Grosse-Knetter (Universitaet Bielefeld) | Hamiltonian Quantization of Effective Lagrangians with Massive Vector
Fields | 16 pages LaTeX, BI-TP 93/17 | Phys.Rev. D48 (1993) 2854-2864 | 10.1103/PhysRevD.48.2854 | null | hep-ph hep-th | null | Effective Lagrangians containing arbitrary interactions of massive vector
fields are quantized within the Hamiltonian path integral formalism. It is
proven that correct Hamiltonian quantization of these models yields the same
result as naive Lagrangian quantization (Matthews's theorem). This theorem
holds for models without gauge freedom as well as for (linearly or nonlinearly
realized) spontaneously broken gauge theories. The Stueckelberg formalism, a
procedure to rewrite effective Lagrangians in a gauge invariant way, is
reformulated within the Hamiltonian formalism as a transition from a second
class constrained theory to an equivalent first class constrained theory. The
relations between linearly and nonlinearly realized spontaneously broken gauge
theories are discussed. The quartically divergent Higgs self interaction is
derived from the Hamiltonian path integral.
| [
{
"created": "Wed, 28 Apr 1993 00:37:20 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Grosse-Knetter",
"Carsten",
"",
"Universitaet Bielefeld"
]
] | Effective Lagrangians containing arbitrary interactions of massive vector fields are quantized within the Hamiltonian path integral formalism. It is proven that correct Hamiltonian quantization of these models yields the same result as naive Lagrangian quantization (Matthews's theorem). This theorem holds for models without gauge freedom as well as for (linearly or nonlinearly realized) spontaneously broken gauge theories. The Stueckelberg formalism, a procedure to rewrite effective Lagrangians in a gauge invariant way, is reformulated within the Hamiltonian formalism as a transition from a second class constrained theory to an equivalent first class constrained theory. The relations between linearly and nonlinearly realized spontaneously broken gauge theories are discussed. The quartically divergent Higgs self interaction is derived from the Hamiltonian path integral. |
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