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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0506200 | Michael Edmund Tobar | Michael E. Tobar, Paul L. Stanwix, Mohamad Susli, Peter Wolf, Clayton
R. Locke, Eugene N. Ivanov | Rotating Resonator-Oscillator Experiments to Test Lorentz Invariance in
Electrodynamics | Submitted to Lecture Notes in Physics, 36 pages, minor modifications,
updated list of references | Lect.Notes Phys.702:416-450,2006 | 10.1007/3-540-34523-X_15 | null | hep-ph astro-ph gr-qc | null | In this work we outline the two most commonly used test theories (RMS and
SME) for testing Local Lorentz Invariance (LLI) of the photon. Then we develop
the general framework of applying these test theories to resonator experiments
with an emphasis on rotating experiments in the laboratory. We compare the
inherent sensitivity factors of common experiments and propose some new
configurations. Finally we apply the test theories to the rotating cryogenic
experiment at the University of Western Australia, which recently set new
limits in both the RMS and SME frameworks [hep-ph/0506074].
| [
{
"created": "Tue, 21 Jun 2005 10:16:52 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Oct 2005 06:22:15 GMT",
"version": "v2"
}
] | 2010-11-19 | [
[
"Tobar",
"Michael E.",
""
],
[
"Stanwix",
"Paul L.",
""
],
[
"Susli",
"Mohamad",
""
],
[
"Wolf",
"Peter",
""
],
[
"Locke",
"Clayton R.",
""
],
[
"Ivanov",
"Eugene N.",
""
]
] | In this work we outline the two most commonly used test theories (RMS and SME) for testing Local Lorentz Invariance (LLI) of the photon. Then we develop the general framework of applying these test theories to resonator experiments with an emphasis on rotating experiments in the laboratory. We compare the inherent sensitivity factors of common experiments and propose some new configurations. Finally we apply the test theories to the rotating cryogenic experiment at the University of Western Australia, which recently set new limits in both the RMS and SME frameworks [hep-ph/0506074]. |
2005.12216 | Claudio Coriano | Claudio Corian\`o, Paul H. Frampton, Alessandro Tatullo | Conformal Unification in a Quiver Theory and Gravitational Waves | 19 pages, 7 Figs. Revised final version, to appear on Phys. Lett. B | null | 10.1016/j.physletb.2020.135909 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The detection of a stochastic background of gravitational waves can reveal
details about first-order phase transitions (FOPTs) at a time of $10^{-13}s$ of
the early universe. We specifically discuss quiver-type GUTs which avoid both
proton decay and a desert hypothesis. A quiver based on $SU(3)^{12}$ which
breaks at a $E=4000$ GeV to trinification $SU(3)^3$ has a much larger
($g_*=1,272$) number of effective massless degrees of freedom than the Standard
Model. Assuming a FOPT for this model we investigate the strain sensitivity of
this model for a wide range of FOPT parameters.
| [
{
"created": "Mon, 25 May 2020 16:33:24 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Oct 2020 21:02:40 GMT",
"version": "v2"
},
{
"created": "Fri, 30 Oct 2020 08:29:45 GMT",
"version": "v3"
}
] | 2020-11-11 | [
[
"Corianò",
"Claudio",
""
],
[
"Frampton",
"Paul H.",
""
],
[
"Tatullo",
"Alessandro",
""
]
] | The detection of a stochastic background of gravitational waves can reveal details about first-order phase transitions (FOPTs) at a time of $10^{-13}s$ of the early universe. We specifically discuss quiver-type GUTs which avoid both proton decay and a desert hypothesis. A quiver based on $SU(3)^{12}$ which breaks at a $E=4000$ GeV to trinification $SU(3)^3$ has a much larger ($g_*=1,272$) number of effective massless degrees of freedom than the Standard Model. Assuming a FOPT for this model we investigate the strain sensitivity of this model for a wide range of FOPT parameters. |
hep-ph/9310364 | null | H. Georgi, L. Kaplan, and D. Morin | Nonperturbative Matching for Field Theories with Heavy Fermions | 10 pages, no figures, uses harvmac, Harvard University Preprint
HUTP-93/A030 | Phys.Rev.D49:2457-2461,1994 | 10.1103/PhysRevD.49.2457 | null | hep-ph hep-th | null | We examine a paradox, suggested by Banks and Dabholkar, concerning
nonperturbative effects in an effective field theory which is obtained by
integrating out a generation of heavy fermions, where the heavy fermion masses
arise from Yukawa couplings. They argue that light fermions in the effective
theory appear to decay via instanton processes, whereas their decay is
forbidden in the full theory. We resolve this paradox by showing that such
processes in fact do not occur in the effective theory, due to matching
corrections which cause the relevant light field configurations to have
infinite action.
| [
{
"created": "Wed, 27 Oct 1993 18:49:22 GMT",
"version": "v1"
}
] | 2009-09-11 | [
[
"Georgi",
"H.",
""
],
[
"Kaplan",
"L.",
""
],
[
"Morin",
"D.",
""
]
] | We examine a paradox, suggested by Banks and Dabholkar, concerning nonperturbative effects in an effective field theory which is obtained by integrating out a generation of heavy fermions, where the heavy fermion masses arise from Yukawa couplings. They argue that light fermions in the effective theory appear to decay via instanton processes, whereas their decay is forbidden in the full theory. We resolve this paradox by showing that such processes in fact do not occur in the effective theory, due to matching corrections which cause the relevant light field configurations to have infinite action. |
0804.0559 | Oleg Lychkovskiy | B. Kerbikov and O. Lychkovskiy | Neutron-Mirror-Neutron Oscillations in a Trap | v4: typos corrected | Phys. Rev. C 77, 065504 (2008) | 10.1103/PhysRevC.77.065504 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the rate of neutron-mirror-neutron oscillations for ultracold
neutrons trapped in a storage vessel. Recent experimental bounds on the
oscillation time are discussed.
| [
{
"created": "Thu, 3 Apr 2008 13:58:26 GMT",
"version": "v1"
},
{
"created": "Sun, 13 Apr 2008 11:54:24 GMT",
"version": "v2"
},
{
"created": "Mon, 19 May 2008 15:22:15 GMT",
"version": "v3"
},
{
"created": "Sun, 1 Jun 2008 16:39:57 GMT",
"version": "v4"
}
] | 2009-11-13 | [
[
"Kerbikov",
"B.",
""
],
[
"Lychkovskiy",
"O.",
""
]
] | We calculate the rate of neutron-mirror-neutron oscillations for ultracold neutrons trapped in a storage vessel. Recent experimental bounds on the oscillation time are discussed. |
1203.4412 | Igor Strakovsky | W. Chen (Duke U.), H. Gao (Duke U.), W. J. Briscoe (GW), D. Dutta
(MSU), A. E. Kudryavtsev (ITEP/GW), M. Mirazita (INFN), M. Paris (LANL), P.
Rossi (INFN), S. Stepanyan (JLab), I. I. Strakovsky (GW), V. E. Tarasov
(ITEP), and R. L. Workman (GW) | Amplitude analysis of gamma n --> pi- p data above 1 GeV | 11 pages, 7 figures, 2 tables | null | 10.1103/PhysRevC.86.015206 | null | hep-ph hep-ex nucl-ex nucl-th | http://creativecommons.org/licenses/by/3.0/ | We report a new extraction of nucleon resonance couplings using pi-
photoproduction cross sections on the neutron. The world database for the
process gamma n --> pi- p above 1 GeV has quadrupled with the addition of new
differential cross sections from the CEBAF Large Acceptance Spectrometer (CLAS)
at Jefferson Lab in Hall B. Differential cross sections from CLAS have been
improved with a new final-state interaction determination using a diagramatic
technique taking into account the NN and piN final-state interaction
amplitudes. Resonance couplings have been extracted and compared to previous
determinations. With the addition of these new cross sections, significant
changes are seen in the high-energy behavior of the SAID cross sections and
amplitudes.
| [
{
"created": "Tue, 20 Mar 2012 12:44:05 GMT",
"version": "v1"
},
{
"created": "Sun, 1 Apr 2012 18:28:00 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Chen",
"W.",
"",
"Duke U."
],
[
"Gao",
"H.",
"",
"Duke U."
],
[
"Briscoe",
"W. J.",
"",
"GW"
],
[
"Dutta",
"D.",
"",
"MSU"
],
[
"Kudryavtsev",
"A. E.",
"",
"ITEP/GW"
],
[
"Mirazita",
"M.",
"",
"INF... | We report a new extraction of nucleon resonance couplings using pi- photoproduction cross sections on the neutron. The world database for the process gamma n --> pi- p above 1 GeV has quadrupled with the addition of new differential cross sections from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab in Hall B. Differential cross sections from CLAS have been improved with a new final-state interaction determination using a diagramatic technique taking into account the NN and piN final-state interaction amplitudes. Resonance couplings have been extracted and compared to previous determinations. With the addition of these new cross sections, significant changes are seen in the high-energy behavior of the SAID cross sections and amplitudes. |
1310.5129 | Tevong You | Feng Luo and Tevong You | Enhancement of Majorana Dark Matter Annihilation Through Higgs
Bremsstrahlung | 17 pages, 7 figures | null | 10.1088/1475-7516/2013/12/024 | KCL-PH-TH/2013-35, LCTS/2013-23 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For Majorana dark matter, gauge boson bremsstrahlung plays an important role
in enhancing an otherwise helicity-suppressed s-wave annihilation
cross-section. This is well known for processes involving a radiated photon or
gluon together with a Standard Model fermion-antifermion pair, and the case of
massive electroweak gauge bosons has also recently been studied. Here we show
that internal Higgs bremsstrahlung also lifts helicity suppression and could be
the dominant contribution to the annihilation rate in the late Universe for
dark matter masses below ~1 TeV. Using a toy model of leptophilic dark matter,
we calculate the annihilation cross-section into a lepton-antilepton pair with
a Higgs boson and investigate the energy spectra of the final stable particles
at the annihilation point.
| [
{
"created": "Fri, 18 Oct 2013 18:59:14 GMT",
"version": "v1"
}
] | 2015-06-17 | [
[
"Luo",
"Feng",
""
],
[
"You",
"Tevong",
""
]
] | For Majorana dark matter, gauge boson bremsstrahlung plays an important role in enhancing an otherwise helicity-suppressed s-wave annihilation cross-section. This is well known for processes involving a radiated photon or gluon together with a Standard Model fermion-antifermion pair, and the case of massive electroweak gauge bosons has also recently been studied. Here we show that internal Higgs bremsstrahlung also lifts helicity suppression and could be the dominant contribution to the annihilation rate in the late Universe for dark matter masses below ~1 TeV. Using a toy model of leptophilic dark matter, we calculate the annihilation cross-section into a lepton-antilepton pair with a Higgs boson and investigate the energy spectra of the final stable particles at the annihilation point. |
1807.02897 | Tamas Cs\"org\H{o} | T. Csorgo, R. Pasechnik, A. Ster | Odderon and proton substructure from a model-independent Levy imaging of
elastic $pp$ and $p\bar p$ collisions | 52 pages, 42 figures; author's recommended version as minor typos in
the EPJ C published version are also fixed here | Eur.Phys.J. C79 (2019) no.1, 62 | 10.1140/epjc/s10052-019-6588-8 | null | hep-ph hep-ex nucl-ex physics.data-an | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe a new and model-independent L\'evy imaging method of quality fits
to the published datasets and reconstruct the amplitude of high-energy $pp$ and
$p\bar p$ elastic scattering processes. This method allows us to determine the
excitation function of the shadow profile $P(b)$, the elastic slope $B(t)$ and
the nuclear phase $\phi(t)$ functions of $pp$ and $p\bar p$ collisions directly
from the data. Surprisingly, notable qualitative differences in $B(t)$ for $pp$
and for $p\bar p$ collisions point towards an Odderon effect. As a by-product,
we clearly identify the proton substructure with two different sizes at the ISR
and LHC energies, that has striking similarity to a dressed quark (at the ISR)
and a dressed diquark (at the LHC). We present model-independent results for
the corresponding sizes and cross-sections for such a substructure for the
existing data at different energies.
| [
{
"created": "Sun, 8 Jul 2018 23:32:32 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Sep 2018 19:56:35 GMT",
"version": "v2"
},
{
"created": "Tue, 15 Jan 2019 22:54:15 GMT",
"version": "v3"
},
{
"created": "Thu, 13 Feb 2020 11:20:42 GMT",
"version": "v4"
}
] | 2020-02-14 | [
[
"Csorgo",
"T.",
""
],
[
"Pasechnik",
"R.",
""
],
[
"Ster",
"A.",
""
]
] | We describe a new and model-independent L\'evy imaging method of quality fits to the published datasets and reconstruct the amplitude of high-energy $pp$ and $p\bar p$ elastic scattering processes. This method allows us to determine the excitation function of the shadow profile $P(b)$, the elastic slope $B(t)$ and the nuclear phase $\phi(t)$ functions of $pp$ and $p\bar p$ collisions directly from the data. Surprisingly, notable qualitative differences in $B(t)$ for $pp$ and for $p\bar p$ collisions point towards an Odderon effect. As a by-product, we clearly identify the proton substructure with two different sizes at the ISR and LHC energies, that has striking similarity to a dressed quark (at the ISR) and a dressed diquark (at the LHC). We present model-independent results for the corresponding sizes and cross-sections for such a substructure for the existing data at different energies. |
0910.2988 | Howard Baer | Howard Baer, Sabine Kraml, Andre Lessa, Sezen Sekmen and Heaya Summy | Beyond the Higgs boson at the Tevatron: detecting gluinos from
Yukawa-unified SUSY | 16 pages including 7 .eps figures | Phys.Lett.B685:72-78,2010 | 10.1016/j.physletb.2010.01.035 | LPSC09155 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Simple SUSY GUT models based on the gauge group SO(10) require t-b-\tau
Yukawa coupling unification, in addition to gauge coupling and matter
unification. The Yukawa coupling unification places strong constraints on the
expected superparticle mass spectrum, with scalar masses \sim 10 TeV while
gluino masses are much lighter: in the 300--500 GeV range. The very heavy
squarks suppress negative interference in the q\bar{q}\to\tg\tg cross section,
leading to a large enhancement in production rates. The gluinos decay almost
always via three-body modes into a pair of b-quarks, so we expect at least four
b-jets per signal event. We investigate the capability of Fermilab Tevatron
collider experiments to detect gluino pair production in Yukawa-unified SUSY.
By requiring events with large missing E_T and \ge 2 or 3 tagged b-jets, we
find a 5\sigma reach in excess of m_{\tg}\sim 400 GeV for 5 fb^{-1} of data.
This range in m_{\tg} is much further than the conventional Tevatron SUSY
reach, and should cut a significant swath through the most favored region of
parameter space for Yukawa-unified SUSY models.
| [
{
"created": "Thu, 15 Oct 2009 20:06:46 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Jan 2010 16:20:23 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Baer",
"Howard",
""
],
[
"Kraml",
"Sabine",
""
],
[
"Lessa",
"Andre",
""
],
[
"Sekmen",
"Sezen",
""
],
[
"Summy",
"Heaya",
""
]
] | Simple SUSY GUT models based on the gauge group SO(10) require t-b-\tau Yukawa coupling unification, in addition to gauge coupling and matter unification. The Yukawa coupling unification places strong constraints on the expected superparticle mass spectrum, with scalar masses \sim 10 TeV while gluino masses are much lighter: in the 300--500 GeV range. The very heavy squarks suppress negative interference in the q\bar{q}\to\tg\tg cross section, leading to a large enhancement in production rates. The gluinos decay almost always via three-body modes into a pair of b-quarks, so we expect at least four b-jets per signal event. We investigate the capability of Fermilab Tevatron collider experiments to detect gluino pair production in Yukawa-unified SUSY. By requiring events with large missing E_T and \ge 2 or 3 tagged b-jets, we find a 5\sigma reach in excess of m_{\tg}\sim 400 GeV for 5 fb^{-1} of data. This range in m_{\tg} is much further than the conventional Tevatron SUSY reach, and should cut a significant swath through the most favored region of parameter space for Yukawa-unified SUSY models. |
hep-ph/9803380 | John McDonald | Kari Enqvist and John McDonald | B-ball Baryogenesis and the Baryon to Dark Matter Ratio | 39 pages, LaTeX, Final version (To be published in Nuc.Phys.B) | Nucl.Phys. B538 (1999) 321-350 | 10.1016/S0550-3213(98)00695-6 | HIP-1998-18/ph | hep-ph astro-ph | null | We demonstrate that B-ball decay in the MSSM can naturally solve the puzzle
of why the densities of baryons and dark matter in the Universe are similar.
This requires that the B-balls survive thermalization and decay below the
freeze-out temperature of the neutralino LSP, typically 1-10GeV. It is shown
that this can happen if the baryon asymmetry originates from a squark
condensate along the d=6 u^{c}d^{c}d^{c} D-flat direction of the MSSM scalar
potential. For this to work the reheating temperature after inflation must be
no greater than 10^3-10^5 GeV.
| [
{
"created": "Wed, 18 Mar 1998 16:03:55 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Jun 1998 13:22:25 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Oct 1998 15:03:37 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Enqvist",
"Kari",
""
],
[
"McDonald",
"John",
""
]
] | We demonstrate that B-ball decay in the MSSM can naturally solve the puzzle of why the densities of baryons and dark matter in the Universe are similar. This requires that the B-balls survive thermalization and decay below the freeze-out temperature of the neutralino LSP, typically 1-10GeV. It is shown that this can happen if the baryon asymmetry originates from a squark condensate along the d=6 u^{c}d^{c}d^{c} D-flat direction of the MSSM scalar potential. For this to work the reheating temperature after inflation must be no greater than 10^3-10^5 GeV. |
1312.5624 | Gerhard Buchalla | Gerhard Buchalla, Oscar Cata, Claudius Krause | On the Power Counting in Effective Field Theories | 14 pages, no figures | null | 10.1016/j.physletb.2014.02.015 | LMU-ASC 81/13 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the systematics of power counting in general effective field
theories, focussing on those that are nonrenormalizable at leading order. As an
illuminating example we consider chiral perturbation theory gauged under the
electromagnetic $U(1)$ symmetry. This theory describes the low-energy
interactions of the octet of pseudo-Goldstone bosons in QCD with photons and
has been discussed extensively in the literature. Peculiarities of the standard
approach are pointed out and it is shown how these are resolved within our
scheme. The presentation follows closely our recent discussion of power
counting for the electroweak chiral Lagrangian. The systematics of the latter
is reviewed and shown to be consistent with the concept of chiral dimensions.
The results imply that naive dimensional analysis (NDA) is incomplete in
general effective field theories, while still reproducing the correct counting
in special cases.
| [
{
"created": "Thu, 19 Dec 2013 16:32:26 GMT",
"version": "v1"
}
] | 2014-04-09 | [
[
"Buchalla",
"Gerhard",
""
],
[
"Cata",
"Oscar",
""
],
[
"Krause",
"Claudius",
""
]
] | We discuss the systematics of power counting in general effective field theories, focussing on those that are nonrenormalizable at leading order. As an illuminating example we consider chiral perturbation theory gauged under the electromagnetic $U(1)$ symmetry. This theory describes the low-energy interactions of the octet of pseudo-Goldstone bosons in QCD with photons and has been discussed extensively in the literature. Peculiarities of the standard approach are pointed out and it is shown how these are resolved within our scheme. The presentation follows closely our recent discussion of power counting for the electroweak chiral Lagrangian. The systematics of the latter is reviewed and shown to be consistent with the concept of chiral dimensions. The results imply that naive dimensional analysis (NDA) is incomplete in general effective field theories, while still reproducing the correct counting in special cases. |
hep-ph/0512313 | Stephen King | I.de Medeiros Varzielas, S.F.King and G.G.Ross | Tri-bimaximal neutrino mixing from discrete subgroups of SU(3) and SO(3)
family symmetry | 10 pages, Latex | Phys.Lett.B644:153-157,2007 | 10.1016/j.physletb.2006.11.015 | null | hep-ph | null | It has recently been shown how tri-bimaximal neutrino mixing can be achieved,
using the see-saw mechanism with constrained sequential dominance, through the
vacuum alignment of a broken non-Abelian gauged family symmetry such as SO(3)
or SU(3). Generalising the approach of Altarelli and Feruglio developed for an
$A_4$ model we show how the reduction of the underlying symmetry to a discrete
subgroup of SO(3) or SU(3) renders this alignment a generic property of such
models. This means near tri-bimaximal mixing can be quite naturally
accommodated in a complete unified theory of quark and lepton masses.
| [
{
"created": "Fri, 23 Dec 2005 13:12:55 GMT",
"version": "v1"
}
] | 2010-04-06 | [
[
"Varzielas",
"I. de Medeiros",
""
],
[
"King",
"S. F.",
""
],
[
"Ross",
"G. G.",
""
]
] | It has recently been shown how tri-bimaximal neutrino mixing can be achieved, using the see-saw mechanism with constrained sequential dominance, through the vacuum alignment of a broken non-Abelian gauged family symmetry such as SO(3) or SU(3). Generalising the approach of Altarelli and Feruglio developed for an $A_4$ model we show how the reduction of the underlying symmetry to a discrete subgroup of SO(3) or SU(3) renders this alignment a generic property of such models. This means near tri-bimaximal mixing can be quite naturally accommodated in a complete unified theory of quark and lepton masses. |
hep-ph/0101059 | Carsten Vogt | C. Vogt | The skewed quark distribution of the pion at large momentum transfer | 10 pages, latex, 3 figures; v3: erratum added | Phys.Rev.D64:057501,2001; Erratum-ibid.D69:079901,2004 | 10.1103/PhysRevD.64.057501 10.1103/PhysRevD.69.079901 | WU B 00-21 | hep-ph | null | We derive an explicit and model-independent representation for the skewed
quark distribution of the pion in the limit of large momentum transfer. Our
result is expressed in terms of the conventional pion distribution amplitudes
and complies with known properties of skewed parton distributions such as
symmetry and polynomiality conditions. The continuity of the result at the
points \pm \xi is manifest, whereas its derivatives exhibit discontinuities.
| [
{
"created": "Mon, 8 Jan 2001 10:44:32 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Jun 2001 08:38:22 GMT",
"version": "v2"
},
{
"created": "Wed, 17 Mar 2004 20:12:32 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Vogt",
"C.",
""
]
] | We derive an explicit and model-independent representation for the skewed quark distribution of the pion in the limit of large momentum transfer. Our result is expressed in terms of the conventional pion distribution amplitudes and complies with known properties of skewed parton distributions such as symmetry and polynomiality conditions. The continuity of the result at the points \pm \xi is manifest, whereas its derivatives exhibit discontinuities. |
1310.5686 | Mohammad Moosavi Nejad | S. Mohammad Moosavi Nejad | Energy spectrum of bottom- and charmed-flavored mesons from polarized
top quark decay $t(\uparrow)\rightarrow W^+ + B/D+X$ at ${\cal O}(\alpha_s)$ | null | Phys.Rev. D88 (2013) no.9, 094011 | 10.1103/PhysRevD.88.094011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the decay of a polarized top quark into a stable $W^+$ boson and
charmed-flavored (D) or bottom-flavored (B) hadrons, via
$t(\uparrow)\rightarrow W^++D/B+X$. We study the angular distribution of the
scaled-energy of B/D-hadrons at next-to-leading order (NLO) considering the
contribution of bottom and gluon fragmentations into the heavy mesons B and D.
To obtain the energy spectrum of B/D-hadrons we present our analytical
expressions for the parton-level differential decay widths of
$t(\uparrow)\rightarrow b+W^+(+g)$ at NLO. Comparison of our predictions with
data at the LHC enable us to test the universality and scaling violations of
the B- and D-hadron fragmentation functions (FFs). These can also be used to
determine the polarization states of top quarks and since the energy
distributions depend on the ratio $m_W /m_t$ we advocate the use of such
angular decay measurements for the determination of the top quark's mass.
| [
{
"created": "Mon, 21 Oct 2013 19:46:01 GMT",
"version": "v1"
}
] | 2016-10-19 | [
[
"Nejad",
"S. Mohammad Moosavi",
""
]
] | We consider the decay of a polarized top quark into a stable $W^+$ boson and charmed-flavored (D) or bottom-flavored (B) hadrons, via $t(\uparrow)\rightarrow W^++D/B+X$. We study the angular distribution of the scaled-energy of B/D-hadrons at next-to-leading order (NLO) considering the contribution of bottom and gluon fragmentations into the heavy mesons B and D. To obtain the energy spectrum of B/D-hadrons we present our analytical expressions for the parton-level differential decay widths of $t(\uparrow)\rightarrow b+W^+(+g)$ at NLO. Comparison of our predictions with data at the LHC enable us to test the universality and scaling violations of the B- and D-hadron fragmentation functions (FFs). These can also be used to determine the polarization states of top quarks and since the energy distributions depend on the ratio $m_W /m_t$ we advocate the use of such angular decay measurements for the determination of the top quark's mass. |
1002.0602 | Kyoungchul Kong | Kyoungchul Kong, Seong Chan Park, Thomas G. Rizzo | Collider Phenomenology with Split-UED | 23 pages, 15 figures | JHEP 1004:081,2010 | 10.1007/JHEP04(2010)081 | IPMU10-0020, SLAC-PUB-13946 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the collider implications of Split Universal Extra Dimensions.
The non-vanishing fermion mass in the bulk, which is consistent with the
KK-parity, largely modifies the phenomenology of Minimal Universal Exta
Dimensions. We scrutinize the behavior of couplings and study the discovery
reach of the Tevatron and the LHC for level-2 Kaluza-Klein modes in the
dilepton channel, which would indicates the presence of the extra dimensions.
Observation of large event rates for dilepton resonances can result from a
nontrivial fermion mass profile along the extra dimensions, which, in turn, may
corroborate extra dimensional explanation for the observation of the positron
excess in cosmic rays.
| [
{
"created": "Tue, 2 Feb 2010 21:22:42 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Kong",
"Kyoungchul",
""
],
[
"Park",
"Seong Chan",
""
],
[
"Rizzo",
"Thomas G.",
""
]
] | We investigate the collider implications of Split Universal Extra Dimensions. The non-vanishing fermion mass in the bulk, which is consistent with the KK-parity, largely modifies the phenomenology of Minimal Universal Exta Dimensions. We scrutinize the behavior of couplings and study the discovery reach of the Tevatron and the LHC for level-2 Kaluza-Klein modes in the dilepton channel, which would indicates the presence of the extra dimensions. Observation of large event rates for dilepton resonances can result from a nontrivial fermion mass profile along the extra dimensions, which, in turn, may corroborate extra dimensional explanation for the observation of the positron excess in cosmic rays. |
hep-ph/0204173 | Sandhya Choubey | Abhijit Bandyopadhyay, Sandhya Choubey, Srubabati Goswami | Neutrino decay confronts the SNO data | 15 pages, LaTex. Updated with the full SNO day-night spectrum data | Phys.Lett.B555:33-42,2003 | 10.1016/S0370-2693(03)00044-3 | null | hep-ph | null | We investigate the status of the neutrino decay solution to the solar
neutrino problem in the context of the recent results from Sudbury Neutrino
Observatory (SNO). We present the results of global $\chi^2$-analysis for both
two and three generation cases with one of the mass states being allowed to
decay and include the effect of both decay and mixing. We find that the Large
Mixing Angle (LMA) region which is the currently favoured solution of the solar
neutrino problem is affected significantly by decay. We present the allowed
areas in the $\Delta m^2-\tan^2\theta$ plane for different allowed values of
$\alpha$ and examine how these areas change with the inclusion of decay. We
obtain bounds on the decay constant $\alpha$ in this region which implies a
rest frame life time $\tau_0/m_{2} > 8.7 \times 10^{-5}$ sec/eV for the
unstable neutrino state. We conclude that the arrival of the neutral current
results from SNO further disfavors the neutrino decay solution to the solar
neutrino problem leaving a very small window for the decay constant $\alpha$
which could still be allowed.
| [
{
"created": "Mon, 15 Apr 2002 16:05:06 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Sep 2002 14:11:15 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Bandyopadhyay",
"Abhijit",
""
],
[
"Choubey",
"Sandhya",
""
],
[
"Goswami",
"Srubabati",
""
]
] | We investigate the status of the neutrino decay solution to the solar neutrino problem in the context of the recent results from Sudbury Neutrino Observatory (SNO). We present the results of global $\chi^2$-analysis for both two and three generation cases with one of the mass states being allowed to decay and include the effect of both decay and mixing. We find that the Large Mixing Angle (LMA) region which is the currently favoured solution of the solar neutrino problem is affected significantly by decay. We present the allowed areas in the $\Delta m^2-\tan^2\theta$ plane for different allowed values of $\alpha$ and examine how these areas change with the inclusion of decay. We obtain bounds on the decay constant $\alpha$ in this region which implies a rest frame life time $\tau_0/m_{2} > 8.7 \times 10^{-5}$ sec/eV for the unstable neutrino state. We conclude that the arrival of the neutral current results from SNO further disfavors the neutrino decay solution to the solar neutrino problem leaving a very small window for the decay constant $\alpha$ which could still be allowed. |
1801.10165 | Jean-Fran\c{c}ois Fortin | Jean-Fran\c{c}ois Fortin, Nicolas Giasson, Luc Marleau | Probability Density Functions for CP-Violating Rephasing Invariants | 1+15 pages, 2 figures | null | 10.1016/j.nuclphysb.2018.03.009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The implications of the anarchy principle on CP violation in the lepton
sector are investigated. A systematic method is introduced to compute the
probability density functions for the CP-violating rephasing invariants of the
PMNS matrix from the Haar measure relevant to the anarchy principle. Contrary
to the CKM matrix which is hierarchical, it is shown that the Haar measure, and
hence the anarchy principle, are very likely to lead to the observed PMNS
matrix. Predictions on the CP-violating Dirac rephasing invariant $|j_D|$ and
Majorana rephasing invariant $|j_1|$ are also obtained. They correspond to
$\langle|j_D|\rangle_\text{Haar}=\pi/105\approx0.030$ and
$\langle|j_1|\rangle_\text{Haar}=1/(6\pi)\approx0.053$ respectively, in
agreement with the experimental hint from T2K of
$|j_D^\text{exp}|\approx0.032\pm0.005$ (or $\approx0.033\pm0.003$) for the
normal (or inverted) hierarchy.
| [
{
"created": "Tue, 30 Jan 2018 19:00:03 GMT",
"version": "v1"
}
] | 2018-04-18 | [
[
"Fortin",
"Jean-François",
""
],
[
"Giasson",
"Nicolas",
""
],
[
"Marleau",
"Luc",
""
]
] | The implications of the anarchy principle on CP violation in the lepton sector are investigated. A systematic method is introduced to compute the probability density functions for the CP-violating rephasing invariants of the PMNS matrix from the Haar measure relevant to the anarchy principle. Contrary to the CKM matrix which is hierarchical, it is shown that the Haar measure, and hence the anarchy principle, are very likely to lead to the observed PMNS matrix. Predictions on the CP-violating Dirac rephasing invariant $|j_D|$ and Majorana rephasing invariant $|j_1|$ are also obtained. They correspond to $\langle|j_D|\rangle_\text{Haar}=\pi/105\approx0.030$ and $\langle|j_1|\rangle_\text{Haar}=1/(6\pi)\approx0.053$ respectively, in agreement with the experimental hint from T2K of $|j_D^\text{exp}|\approx0.032\pm0.005$ (or $\approx0.033\pm0.003$) for the normal (or inverted) hierarchy. |
1401.1222 | Thomas Luebbert | Thomas Gehrmann, Thomas Luebbert, Li Lin Yang | Transverse Parton Distribution Functions at
Next-To-Next-To-Leading-Order | 10 pages, 1 figure, presented at the 11th International Symposium on
Radiative Corrections, RADCOR 2013, 22.-27. September 2013, Lumley Castle,
Durham, UK | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a perturbative calculation of the transverse parton distribution
functions in all partonic channels up to next-to-next-to-leading order based on
a gauge invariant operator definition. We demonstrate for the first time that
such a definition works beyond the first non-trivial order. We extract the
coefficient functions relevant for a next-to-next-to-next-to-leading
logarithmic $q_T$ resummation in a large class of processes at hadron
colliders.
| [
{
"created": "Mon, 6 Jan 2014 21:02:19 GMT",
"version": "v1"
}
] | 2014-01-08 | [
[
"Gehrmann",
"Thomas",
""
],
[
"Luebbert",
"Thomas",
""
],
[
"Yang",
"Li Lin",
""
]
] | We present a perturbative calculation of the transverse parton distribution functions in all partonic channels up to next-to-next-to-leading order based on a gauge invariant operator definition. We demonstrate for the first time that such a definition works beyond the first non-trivial order. We extract the coefficient functions relevant for a next-to-next-to-next-to-leading logarithmic $q_T$ resummation in a large class of processes at hadron colliders. |
1710.10371 | Chungku Kim | Chungku Kim | Renormalization Group Invariance of the Pole Mass in the Multi-Higgs
system | null | null | 10.3938/jkps.72.1287 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have investigated the renormalization group running of the pole mass in
the multi-Higgs theory in two different types of the gauge fixing conditions.
It turns out that the pole mass when expressed in terms of the Lagrangian
parameters, is invariant under the renormalization group with the beta and
gamma functions of the symmetric phase.
| [
{
"created": "Sat, 28 Oct 2017 02:15:27 GMT",
"version": "v1"
}
] | 2018-07-04 | [
[
"Kim",
"Chungku",
""
]
] | We have investigated the renormalization group running of the pole mass in the multi-Higgs theory in two different types of the gauge fixing conditions. It turns out that the pole mass when expressed in terms of the Lagrangian parameters, is invariant under the renormalization group with the beta and gamma functions of the symmetric phase. |
1301.1437 | Pankaj Sharma | Eung Jin Chun and Pankaj Sharma | A light triplet boson and Higgs-to-diphoton in supersymmetric type II
seesaw | Addition of the Higgs decay to the doubly charged bosons and more
references | null | 10.1016/j.physletb.2013.03.038 | KIAS-P13005 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The supersymmetric type II seesaw may leave a limit where a triplet boson
along with the standard Higgs boson remains light. Working in this limit with
small triplet vacuum expectation vlaues, we explore how much such a light
triplet boson can contribute to the Higgs boson decay to diphoton, and analyze
the feasibility to observe it through same-sign di-lepton and tetra-lepton
signals in the forthcoming LHC run after setting a LHC7 limit in a simplified
parameter space of the triplet vaccum expectation value and the doubly charged
boson mass.
| [
{
"created": "Tue, 8 Jan 2013 08:00:30 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Jan 2013 03:52:36 GMT",
"version": "v2"
}
] | 2015-06-12 | [
[
"Chun",
"Eung Jin",
""
],
[
"Sharma",
"Pankaj",
""
]
] | The supersymmetric type II seesaw may leave a limit where a triplet boson along with the standard Higgs boson remains light. Working in this limit with small triplet vacuum expectation vlaues, we explore how much such a light triplet boson can contribute to the Higgs boson decay to diphoton, and analyze the feasibility to observe it through same-sign di-lepton and tetra-lepton signals in the forthcoming LHC run after setting a LHC7 limit in a simplified parameter space of the triplet vaccum expectation value and the doubly charged boson mass. |
hep-ph/0011391 | Philippe Ruelle | J.-M. Gerard and J. Weyers | Trace anomalies and the $\Delta I = 1/2$ rule | 10 pages, no figure | Phys.Lett. B503 (2001) 99-103 | 10.1016/S0370-2693(01)00213-1 | UCL-IPT-00-17 | hep-ph | null | Trace Anomaly Dominance in weak $K$-decays successfully reproduces the
$\Delta I = {1\over 2}$ selection rule results, as observed in $K_S \to \pi\pi,
K_L \to \pi\pi\pi, K_S \to \gamma\gamma$ and $K_L \to \pi^0 \gamma\gamma$.
| [
{
"created": "Thu, 30 Nov 2000 14:23:22 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Gerard",
"J. -M.",
""
],
[
"Weyers",
"J.",
""
]
] | Trace Anomaly Dominance in weak $K$-decays successfully reproduces the $\Delta I = {1\over 2}$ selection rule results, as observed in $K_S \to \pi\pi, K_L \to \pi\pi\pi, K_S \to \gamma\gamma$ and $K_L \to \pi^0 \gamma\gamma$. |
1409.1321 | Mikhail Zubkov Dr | M.A. Zubkov | Schwinger - Dyson equation and NJL approximation in massive gauge theory
with fermions | Latex, 16 pages, published version | Annals of Physics 354 (2015), pp. 72-88 | 10.1016/j.aop.2014.12.007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider massive $SU(N)$ gauge theory with fermions. Gauge bosons become
massive due to the interaction with the scalar field, whose vacuum average
provides the spontaneous breakdown of gauge symmetry. We investigate Dyson -
Schwinger equation for the fermion propagator written in ladder approximation
and in Landau gauge. Our analysis demonstrates that the chiral symmetry
breaking in the considered theory is the strong coupling phenomenon. There are
the indications that there appears the second order phase transition between
chirally broken and symmetric phases of the theory at the value of coupling
constant $\alpha_c = (1+\gamma)\times \frac{\pi}{3}\times \frac{1}{2 C_2(F)}$,
where $0<\gamma<1$, and $\gamma$ depends on the scale, at which the
fluctuations of the scalar field destroy the gauge boson mass. In the broken
phase near the critical value of $\alpha$ the Dyson - Schwinger equation is
approximated well by the gap equation of the effective Nambu - Joina - Lasinio
model with the value of cutoff around gauge boson mass $M$ and the effective
four - fermion coupling constant $\frac{4 \pi \alpha}{M^2}\times
\frac{2C_2(F)}{N}$. The dynamical fermion mass $m$ may be essentially smaller
than $M$.
| [
{
"created": "Thu, 4 Sep 2014 05:28:42 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Sep 2014 19:58:06 GMT",
"version": "v2"
},
{
"created": "Fri, 19 Sep 2014 09:16:47 GMT",
"version": "v3"
},
{
"created": "Mon, 22 Sep 2014 00:37:57 GMT",
"version": "v4"
},
{
"cr... | 2015-01-06 | [
[
"Zubkov",
"M. A.",
""
]
] | We consider massive $SU(N)$ gauge theory with fermions. Gauge bosons become massive due to the interaction with the scalar field, whose vacuum average provides the spontaneous breakdown of gauge symmetry. We investigate Dyson - Schwinger equation for the fermion propagator written in ladder approximation and in Landau gauge. Our analysis demonstrates that the chiral symmetry breaking in the considered theory is the strong coupling phenomenon. There are the indications that there appears the second order phase transition between chirally broken and symmetric phases of the theory at the value of coupling constant $\alpha_c = (1+\gamma)\times \frac{\pi}{3}\times \frac{1}{2 C_2(F)}$, where $0<\gamma<1$, and $\gamma$ depends on the scale, at which the fluctuations of the scalar field destroy the gauge boson mass. In the broken phase near the critical value of $\alpha$ the Dyson - Schwinger equation is approximated well by the gap equation of the effective Nambu - Joina - Lasinio model with the value of cutoff around gauge boson mass $M$ and the effective four - fermion coupling constant $\frac{4 \pi \alpha}{M^2}\times \frac{2C_2(F)}{N}$. The dynamical fermion mass $m$ may be essentially smaller than $M$. |
0707.1255 | Peter Athron | Peter Athron, D. J. Miller | Fine Tuning in Supersymmetric Models | Included in proceedings of The 14th International Conference on
Supersymmetry and the Unification of Fundamental Interactions | null | 10.1063/1.2735202 | null | hep-ph | null | The solution of a fine tuning problem is one of the principal motivations of
Supersymmetry. However experimental constraints indicate that many
Supersymmetric models are also fine tuned (although to a much lesser extent).
We review the traditional measure of this fine tuning used in the literature
and propose an alternative. We apply this to the MSSM and show the
implications.
| [
{
"created": "Mon, 9 Jul 2007 14:25:28 GMT",
"version": "v1"
}
] | 2015-05-13 | [
[
"Athron",
"Peter",
""
],
[
"Miller",
"D. J.",
""
]
] | The solution of a fine tuning problem is one of the principal motivations of Supersymmetry. However experimental constraints indicate that many Supersymmetric models are also fine tuned (although to a much lesser extent). We review the traditional measure of this fine tuning used in the literature and propose an alternative. We apply this to the MSSM and show the implications. |
hep-ph/9803258 | Riccardo Rattazzi | L. Randall, R. Rattazzi and E. Shuryak | Implication of Exact SUSY Gauge Couplings for QCD | 8 pages, 1 eps figure, RevTeX; revised version: references added,
typos corrected | Phys.Rev.D59:035005,1999 | 10.1103/PhysRevD.59.035005 | CERN-TH/98-63 | hep-ph hep-th | null | The phase structure of SUSY gauge theories can be very different from their
nonsupersymmetric counterparts. Nonetheless, there is interesting information
which might be gleaned from detailed investigation of these theories. In
particular, we study the precise meaning of the strong interaction scale
$\Lambda$. We ask whether one can meaningfully apply naive dimensional analysis
and also ask whether the study of supersymmetric theories can shed light on the
apparent discrepancy between the perturbative scale $\Lambda_{QCD}$ and the
``chiral lagrangian'' scale $\Lambda_\chi$. We show that in N=1 supersymmetric
Yang Mills theory, ``naive dimensional analysis'' seems to work well, with
$\Lambda_\chi$ consistently equal to the scale at which the perturbatively
evolved physical coupling becomes of order $4 \pi$. We turn to N=2 theories to
understand better the effect of instantons in accounting for the QCD
discrepancy between scales. In N=2 supersymmetric SU(2) the instanton
corrections are known to all orders from the Seiberg-Witten solution and give
rise to a finite scale ratio between the scale at which the perturbatively
evolved and ``nonperturbatively evolved'' couplings blow up. Correspondingly,
instanton effects are important even when the associated perturbatively evolved
gauge coupling only gives $\alpha$ of order 1 (rather than $4 \pi$). We compare
the N=2 result to instanton-induced corrections in QCD, evaluated using lattice
data and the instanton liquid model, and find a remarkably similar behavior.
| [
{
"created": "Thu, 5 Mar 1998 20:48:51 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Mar 1998 21:04:49 GMT",
"version": "v2"
}
] | 2009-09-15 | [
[
"Randall",
"L.",
""
],
[
"Rattazzi",
"R.",
""
],
[
"Shuryak",
"E.",
""
]
] | The phase structure of SUSY gauge theories can be very different from their nonsupersymmetric counterparts. Nonetheless, there is interesting information which might be gleaned from detailed investigation of these theories. In particular, we study the precise meaning of the strong interaction scale $\Lambda$. We ask whether one can meaningfully apply naive dimensional analysis and also ask whether the study of supersymmetric theories can shed light on the apparent discrepancy between the perturbative scale $\Lambda_{QCD}$ and the ``chiral lagrangian'' scale $\Lambda_\chi$. We show that in N=1 supersymmetric Yang Mills theory, ``naive dimensional analysis'' seems to work well, with $\Lambda_\chi$ consistently equal to the scale at which the perturbatively evolved physical coupling becomes of order $4 \pi$. We turn to N=2 theories to understand better the effect of instantons in accounting for the QCD discrepancy between scales. In N=2 supersymmetric SU(2) the instanton corrections are known to all orders from the Seiberg-Witten solution and give rise to a finite scale ratio between the scale at which the perturbatively evolved and ``nonperturbatively evolved'' couplings blow up. Correspondingly, instanton effects are important even when the associated perturbatively evolved gauge coupling only gives $\alpha$ of order 1 (rather than $4 \pi$). We compare the N=2 result to instanton-induced corrections in QCD, evaluated using lattice data and the instanton liquid model, and find a remarkably similar behavior. |
hep-ph/9812345 | Lam Hui | Lam Hui and Ewan D. Stewart (Fermilab) | Superheavy Dark Matter from Thermal Inflation | references added | Phys. Rev. D 60, 023518 (1999) | 10.1103/PhysRevD.60.023518 | null | hep-ph astro-ph | null | It is quite plausible that the mass of the dark matter particle increases
significantly after its freeze-out, due to a scalar field rolling to large
values. We describe a realization of this scenario in the context of thermal
inflation which naturally gives a cold dark matter particle with the correct
cosmological abundance and a mass around $10^{10} {\rm GeV}$, evading the
conventional upper bound of $10^5 {\rm GeV}$. We also discuss another
realization which could produce a cosmologically interesting abundance of near
Planck mass, possibly electromagnetically charged, particles. The detection and
observational consequences of superheavy cold dark matter or WIMPZILLAs are
briefly examined.
| [
{
"created": "Mon, 14 Dec 1998 21:04:41 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Aug 1999 23:01:47 GMT",
"version": "v2"
}
] | 2016-08-25 | [
[
"Hui",
"Lam",
"",
"Fermilab"
],
[
"Stewart",
"Ewan D.",
"",
"Fermilab"
]
] | It is quite plausible that the mass of the dark matter particle increases significantly after its freeze-out, due to a scalar field rolling to large values. We describe a realization of this scenario in the context of thermal inflation which naturally gives a cold dark matter particle with the correct cosmological abundance and a mass around $10^{10} {\rm GeV}$, evading the conventional upper bound of $10^5 {\rm GeV}$. We also discuss another realization which could produce a cosmologically interesting abundance of near Planck mass, possibly electromagnetically charged, particles. The detection and observational consequences of superheavy cold dark matter or WIMPZILLAs are briefly examined. |
1505.05237 | Robert Szafron | Robert Szafron and Andrzej Czarnecki | High-energy electrons from the muon decay in orbit: radiative
corrections | 7 pages, v2: corrected and improved version | null | 10.1016/j.physletb.2015.12.008 | Alberta Thy 8-15, Fermilab-PUB-15-205-PPD | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We determine the $\mathcal{O}(\alpha)$ correction to the energy spectrum of
electrons produced in the decay of muons bound in atoms. We focus on the
high-energy end of the spectrum that constitutes a background for the
muon-electron conversion and will be precisely measured by the upcoming
experiments Mu2e and COMET. The correction suppresses the background by about
15\%.
| [
{
"created": "Wed, 20 May 2015 03:39:11 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Oct 2015 00:24:40 GMT",
"version": "v2"
}
] | 2016-01-20 | [
[
"Szafron",
"Robert",
""
],
[
"Czarnecki",
"Andrzej",
""
]
] | We determine the $\mathcal{O}(\alpha)$ correction to the energy spectrum of electrons produced in the decay of muons bound in atoms. We focus on the high-energy end of the spectrum that constitutes a background for the muon-electron conversion and will be precisely measured by the upcoming experiments Mu2e and COMET. The correction suppresses the background by about 15\%. |
2009.08264 | Carlo Flore | Carlo Flore, Jean-Philippe Lansberg, Hua-Sheng Shao, Yelyzaveta
Yedelkina | Large-P_T inclusive photoproduction of J/psi in electron-proton
collisions at HERA and the EIC | LaTeX, 11 pages; 15 figures | null | 10.1016/j.physletb.2020.135926 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the inclusive J/psi production at large transverse momenta at
lepton-hadron colliders in the limit when the exchange photon is quasi real,
also referred to as photoproduction. Our computation includes the leading-P_T
leading-v next-to-leading alpha_s corrections. In particular, we consider the
contribution from J/psi plus another charm quark, by employing for the first
time in quarkonium photoproduction the variable-flavour-number scheme. We also
include a QED-induced contribution via an off-shell photon which remained
ignored in the literature and which we show to be the leading contribution at
high P_T within the reach of the EIC. In turn, we use our computation of
J/psi+charm to demonstrate its observability at the future EIC and the EIC
sensitivity to probe the non-perturbative charm content of the proton at high
x.
| [
{
"created": "Thu, 17 Sep 2020 13:07:59 GMT",
"version": "v1"
}
] | 2020-11-11 | [
[
"Flore",
"Carlo",
""
],
[
"Lansberg",
"Jean-Philippe",
""
],
[
"Shao",
"Hua-Sheng",
""
],
[
"Yedelkina",
"Yelyzaveta",
""
]
] | We study the inclusive J/psi production at large transverse momenta at lepton-hadron colliders in the limit when the exchange photon is quasi real, also referred to as photoproduction. Our computation includes the leading-P_T leading-v next-to-leading alpha_s corrections. In particular, we consider the contribution from J/psi plus another charm quark, by employing for the first time in quarkonium photoproduction the variable-flavour-number scheme. We also include a QED-induced contribution via an off-shell photon which remained ignored in the literature and which we show to be the leading contribution at high P_T within the reach of the EIC. In turn, we use our computation of J/psi+charm to demonstrate its observability at the future EIC and the EIC sensitivity to probe the non-perturbative charm content of the proton at high x. |
hep-ph/0304115 | Carlos Munoz | D.G. Cerdeno, E. Gabrielli, M.E. Gomez and C. Munoz | Neutralino-Nucleon Cross Section and Charge and Colour Breaking
Constraints | Final version to appear in JHEP | JHEP 0306:030,2003 | 10.1088/1126-6708/2003/06/030 | DESY 03-024, HIP-2002-57/TH, FTUAM 03/05, IFT-UAM/CSIC-03-09 | hep-ph | null | We compute the neutralino-nucleon cross section in several supersymmetric
scenarios, taking into account all kind of constraints. In particular, the
constraints that the absence of dangerous charge and colour breaking minima
imposes on the parameter space are studied in detail. In addition, the most
recent experimental constraints, such as the lower bound on the Higgs mass, the
$b\to s\gamma$ branching ratio, and the muon $g-2$ are considered. The
astrophysical bounds on the dark matter density are also imposed on the
theoretical computation of the relic neutralino density, assuming thermal
production. This computation is relevant for the theoretical analysis of the
direct detection of dark matter in current experiments. We consider first the
supergravity scenario with universal soft terms and GUT scale. In this scenario
the charge and colour breaking constraints turn out to be quite important, and
$\tan\beta\lsim 20$ is forbidden. Larger values of $\tan\beta$ can also be
forbidden, depending on the value of the trilinear parameter $A$. Finally, we
study supergravity scenarios with an intermediate scale, and also with
non-universal scalar and gaugino masses where the cross section can be very
large.
| [
{
"created": "Fri, 11 Apr 2003 15:17:25 GMT",
"version": "v1"
},
{
"created": "Fri, 16 May 2003 21:50:53 GMT",
"version": "v2"
},
{
"created": "Mon, 30 Jun 2003 16:12:59 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Cerdeno",
"D. G.",
""
],
[
"Gabrielli",
"E.",
""
],
[
"Gomez",
"M. E.",
""
],
[
"Munoz",
"C.",
""
]
] | We compute the neutralino-nucleon cross section in several supersymmetric scenarios, taking into account all kind of constraints. In particular, the constraints that the absence of dangerous charge and colour breaking minima imposes on the parameter space are studied in detail. In addition, the most recent experimental constraints, such as the lower bound on the Higgs mass, the $b\to s\gamma$ branching ratio, and the muon $g-2$ are considered. The astrophysical bounds on the dark matter density are also imposed on the theoretical computation of the relic neutralino density, assuming thermal production. This computation is relevant for the theoretical analysis of the direct detection of dark matter in current experiments. We consider first the supergravity scenario with universal soft terms and GUT scale. In this scenario the charge and colour breaking constraints turn out to be quite important, and $\tan\beta\lsim 20$ is forbidden. Larger values of $\tan\beta$ can also be forbidden, depending on the value of the trilinear parameter $A$. Finally, we study supergravity scenarios with an intermediate scale, and also with non-universal scalar and gaugino masses where the cross section can be very large. |
1610.06571 | Kristjan Kannike | K. Kannike, M. Raidal, C. Spethmann and H. Veerm\"ae | Evolving Planck Mass in Classically Scale-Invariant Theories | 28 pages, 2 figures, version published in JHEP | null | 10.1007/JHEP04(2017)026 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider classically scale-invariant theories with non-minimally coupled
scalar fields, where the Planck mass and the hierarchy of physical scales are
dynamically generated. The classical theories possess a fixed point, where
scale invariance is spontaneously broken. In these theories, however, the
Planck mass becomes unstable in the presence of explicit sources of scale
invariance breaking, such as non-relativistic matter and cosmological constant
terms. We quantify the constraints on such classical models from Big Bang
Nucleosynthesis that lead to an upper bound on the non-minimal coupling and
require trans-Planckian field values. We show that quantum corrections to the
scalar potential can stabilise the fixed point close to the minimum of the
Coleman-Weinberg potential. The time-averaged motion of the evolving fixed
point is strongly suppressed, thus the limits on the evolving gravitational
constant from Big Bang Nucleosynthesis and other measurements do not presently
constrain this class of theories. Field oscillations around the fixed point, if
not damped, contribute to the dark matter density of the Universe.
| [
{
"created": "Thu, 20 Oct 2016 20:00:03 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Oct 2016 13:13:44 GMT",
"version": "v2"
},
{
"created": "Tue, 2 May 2017 08:33:23 GMT",
"version": "v3"
}
] | 2017-05-03 | [
[
"Kannike",
"K.",
""
],
[
"Raidal",
"M.",
""
],
[
"Spethmann",
"C.",
""
],
[
"Veermäe",
"H.",
""
]
] | We consider classically scale-invariant theories with non-minimally coupled scalar fields, where the Planck mass and the hierarchy of physical scales are dynamically generated. The classical theories possess a fixed point, where scale invariance is spontaneously broken. In these theories, however, the Planck mass becomes unstable in the presence of explicit sources of scale invariance breaking, such as non-relativistic matter and cosmological constant terms. We quantify the constraints on such classical models from Big Bang Nucleosynthesis that lead to an upper bound on the non-minimal coupling and require trans-Planckian field values. We show that quantum corrections to the scalar potential can stabilise the fixed point close to the minimum of the Coleman-Weinberg potential. The time-averaged motion of the evolving fixed point is strongly suppressed, thus the limits on the evolving gravitational constant from Big Bang Nucleosynthesis and other measurements do not presently constrain this class of theories. Field oscillations around the fixed point, if not damped, contribute to the dark matter density of the Universe. |
0907.2387 | Robert Thorne S | R.S. Thorne, A.D. Martin, W.J. Stirling and G. Watt | Status of MRST/MSTW PDF sets | To appear in the proceedings of the 17th International Workshop on
Deep Inelastic Scattering, Madrid, April 2009. 5 pages, 1 figure | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We outline the historical development of MRST/MSTW parton distribution
functions (PDFs), and clarify how they should be regarded when compared to the
most up-to-date 2008 MSTW sets, noting which sets are now obsolete and the
reasons why.
| [
{
"created": "Tue, 14 Jul 2009 15:35:38 GMT",
"version": "v1"
}
] | 2009-07-15 | [
[
"Thorne",
"R. S.",
""
],
[
"Martin",
"A. D.",
""
],
[
"Stirling",
"W. J.",
""
],
[
"Watt",
"G.",
""
]
] | We outline the historical development of MRST/MSTW parton distribution functions (PDFs), and clarify how they should be regarded when compared to the most up-to-date 2008 MSTW sets, noting which sets are now obsolete and the reasons why. |
2201.07997 | Dmitry Karlovets | D. V. Karlovets, S. S. Baturin, G. Geloni, G. K. Sizykh, and V. G.
Serbo | Generation of vortex particles via generalized measurements | 11 pages, 2 figures | European Physical Journal C 82(11): 1008 (2022) | 10.1140/epjc/s10052-022-10991-w | null | hep-ph physics.acc-ph quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The hard X-ray twisted photons and relativistic massive particles with
orbital angular momentum -- vortex electrons, muons, protons, etc. -- have many
potential applications in high-energy and nuclear physics. However, such states
can be obtained so far mainly via diffraction techniques, not applicable for
relativistic energies. Here we show that the vortex states of different
particles, including hadrons, ions, and nuclei, can be generated in a large
class of processes with two final particles simply by altering a postselection
protocol. Thanks to entanglement and to the uncertainty relations, an evolved
state of a final particle becomes twisted if the momentum azimuthal angle of
the other particle is measured with a large uncertainty. We give several
examples, including Cherenkov and undulator radiation, particle collisions with
intense laser beams, $e\mu \to e\mu, ep \to ep$. This technique can be adapted
for ultrarelativistic lepton and hadron beams of linear colliders, and it can
also facilitate the development of sources of X-ray and $\gamma$-range twisted
photons at storage rings and free-electron lasers.
| [
{
"created": "Thu, 20 Jan 2022 04:31:22 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Mar 2022 19:17:33 GMT",
"version": "v2"
},
{
"created": "Tue, 30 Aug 2022 11:57:36 GMT",
"version": "v3"
},
{
"created": "Thu, 10 Nov 2022 17:13:14 GMT",
"version": "v4"
}
] | 2022-11-11 | [
[
"Karlovets",
"D. V.",
""
],
[
"Baturin",
"S. S.",
""
],
[
"Geloni",
"G.",
""
],
[
"Sizykh",
"G. K.",
""
],
[
"Serbo",
"V. G.",
""
]
] | The hard X-ray twisted photons and relativistic massive particles with orbital angular momentum -- vortex electrons, muons, protons, etc. -- have many potential applications in high-energy and nuclear physics. However, such states can be obtained so far mainly via diffraction techniques, not applicable for relativistic energies. Here we show that the vortex states of different particles, including hadrons, ions, and nuclei, can be generated in a large class of processes with two final particles simply by altering a postselection protocol. Thanks to entanglement and to the uncertainty relations, an evolved state of a final particle becomes twisted if the momentum azimuthal angle of the other particle is measured with a large uncertainty. We give several examples, including Cherenkov and undulator radiation, particle collisions with intense laser beams, $e\mu \to e\mu, ep \to ep$. This technique can be adapted for ultrarelativistic lepton and hadron beams of linear colliders, and it can also facilitate the development of sources of X-ray and $\gamma$-range twisted photons at storage rings and free-electron lasers. |
hep-ph/0608007 | Jorge Gamboa | Paola Arias, Ashok Das, Jorge Gamboa, Justo Lopez-Sarrion and Fernando
Mendez | CPT/Lorentz Invariance Violation and Neutrino Oscillation | Several portions of the paper was completely re-written and new
references added. To appear in PLB | Phys.Lett.B650:401-406,2007 | 10.1016/j.physletb.2007.05.010 | null | hep-ph astro-ph hep-th | null | We analyze the consequences of violation of Lorentz and $CPT$ invariance in
the massless neutrino sector by deforming the canonical anti-commutation
relations for the fields. We show that, for particular choices of the
deformation, oscillation between massless neutrino species takes place when
only Lorentz invariance is violated. On the other hand, if both Lorentz and
$CPT$ invariances are violated, we show that there is no oscillation between
massless neutrino species. Comparing with the existing experimental data on
neutrino oscillations, we obtain bounds on the parameter for Lorentz invariance
violation.
| [
{
"created": "Tue, 1 Aug 2006 15:32:49 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Aug 2006 22:03:56 GMT",
"version": "v2"
},
{
"created": "Mon, 11 Sep 2006 18:06:07 GMT",
"version": "v3"
},
{
"created": "Thu, 10 May 2007 01:15:15 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Arias",
"Paola",
""
],
[
"Das",
"Ashok",
""
],
[
"Gamboa",
"Jorge",
""
],
[
"Lopez-Sarrion",
"Justo",
""
],
[
"Mendez",
"Fernando",
""
]
] | We analyze the consequences of violation of Lorentz and $CPT$ invariance in the massless neutrino sector by deforming the canonical anti-commutation relations for the fields. We show that, for particular choices of the deformation, oscillation between massless neutrino species takes place when only Lorentz invariance is violated. On the other hand, if both Lorentz and $CPT$ invariances are violated, we show that there is no oscillation between massless neutrino species. Comparing with the existing experimental data on neutrino oscillations, we obtain bounds on the parameter for Lorentz invariance violation. |
1505.03542 | Gustavo Marques-Tavares | Manuel A. Buen-Abad, Gustavo Marques-Tavares, Martin Schmaltz | Non-Abelian dark matter and dark radiation | 25 pages, 8 figures; v2: minor improvements, references added; v3:
added references and an acknowledgement note to J. Lesgourgues; accepted for
publication in PRD | Phys. Rev. D 92, 023531 (2015) | 10.1103/PhysRevD.92.023531 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new class of dark matter models with unusual phenomenology. What
is ordinary about our models is that dark matter particles are WIMPs, they are
weakly coupled to the Standard Model and have weak scale masses. What is
unusual is that they come in multiplets of a new "dark" non-Abelian gauge group
with milli-weak coupling. The massless dark gluons of this dark gauge group
contribute to the energy density of the universe as a form of weakly
self-interacting dark radiation. In this paper we explore the consequences of
having i.) dark matter in multiplets ii.) self-interacting dark radiation and
iii.) dark matter which is weakly coupled to dark radiation. We find that i.)
dark matter cross sections are modified by multiplicity factors which have
significant consequences for collider searches and indirect detection, ii.)
dark gluons have thermal abundances which affect the CMB as dark radiation.
Unlike additional massless neutrino species the dark gluons are interacting and
have vanishing viscosity and iii.) the coupling of dark radiation to dark
matter represents a new mechanism for damping the large scale structure power
spectrum. A combination of additional radiation and slightly damped structure
is interesting because it can remove tensions between global $\Lambda$CDM fits
from the CMB and direct measurements of the Hubble expansion rate ($H_0$) and
large scale structure ($\sigma_8$).
| [
{
"created": "Wed, 13 May 2015 20:08:26 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Jun 2015 21:40:29 GMT",
"version": "v2"
},
{
"created": "Thu, 16 Jul 2015 22:42:31 GMT",
"version": "v3"
}
] | 2015-08-05 | [
[
"Buen-Abad",
"Manuel A.",
""
],
[
"Marques-Tavares",
"Gustavo",
""
],
[
"Schmaltz",
"Martin",
""
]
] | We propose a new class of dark matter models with unusual phenomenology. What is ordinary about our models is that dark matter particles are WIMPs, they are weakly coupled to the Standard Model and have weak scale masses. What is unusual is that they come in multiplets of a new "dark" non-Abelian gauge group with milli-weak coupling. The massless dark gluons of this dark gauge group contribute to the energy density of the universe as a form of weakly self-interacting dark radiation. In this paper we explore the consequences of having i.) dark matter in multiplets ii.) self-interacting dark radiation and iii.) dark matter which is weakly coupled to dark radiation. We find that i.) dark matter cross sections are modified by multiplicity factors which have significant consequences for collider searches and indirect detection, ii.) dark gluons have thermal abundances which affect the CMB as dark radiation. Unlike additional massless neutrino species the dark gluons are interacting and have vanishing viscosity and iii.) the coupling of dark radiation to dark matter represents a new mechanism for damping the large scale structure power spectrum. A combination of additional radiation and slightly damped structure is interesting because it can remove tensions between global $\Lambda$CDM fits from the CMB and direct measurements of the Hubble expansion rate ($H_0$) and large scale structure ($\sigma_8$). |
hep-ph/0009264 | Annabella Rauscher | O. Nachtmann, A. Rauscher | Inclusive Quark Production in $e^{+}e^{-}$-Annihilation - A Path
Integral Approach | Latex, 5 pages, 2 figures, talk given at the QCD 00 Euroconference,
Montpellier, 6-13 July 2000 | Nucl.Phys.Proc.Suppl. 96 (2001) 69-73 | 10.1016/S0920-5632(01)01110-0 | null | hep-ph | null | The single-particle inclusive differential cross-section for a reaction
$a+b\to c+X$ is written as imaginary part of a correlation function in a
forward scattering amplitude for $a+b\to a+b$ in a modified effective theory.
In this modified theory the interaction Hamiltonian $\tilde H_I$ equals $H_I$
of the original theory up to a certain time. Then there is a sign change and
$\tilde H_I$ becomes nonlocal. This is worked out in detail for scalar field
models and for QED plus the abelian gluon model. A suitable path integral for
direct calculations of inclusive cross sections is presented.
| [
{
"created": "Fri, 22 Sep 2000 09:43:51 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Nachtmann",
"O.",
""
],
[
"Rauscher",
"A.",
""
]
] | The single-particle inclusive differential cross-section for a reaction $a+b\to c+X$ is written as imaginary part of a correlation function in a forward scattering amplitude for $a+b\to a+b$ in a modified effective theory. In this modified theory the interaction Hamiltonian $\tilde H_I$ equals $H_I$ of the original theory up to a certain time. Then there is a sign change and $\tilde H_I$ becomes nonlocal. This is worked out in detail for scalar field models and for QED plus the abelian gluon model. A suitable path integral for direct calculations of inclusive cross sections is presented. |
0707.2958 | Joerg Jaeckel | Steven Abel, Callum Durnford, Joerg Jaeckel, Valentin V. Khoze | Dynamical breaking of U(1)_{R} and supersymmetry in a metastable vacuum | 11 pages, 3 figures. v2 improved discussion of the gaugino masses | Phys.Lett.B661:201-209,2008 | 10.1016/j.physletb.2008.01.065 | IPPP/07/39; DCPT/07/78 | hep-ph hep-th | null | We consider the metastable N=1 QCD model of Intriligator, Seiberg and Shih
(ISS), deformed by adding a baryon term to the superpotential. This simple
deformation causes the spontaneous breaking of the approximate R-symmetry of
the metastable vacuum. We then gauge the flavour SU(5)_f and identify it with
the parent gauge symmetry of the Standard Model (SM). This implements direct
mediation of supersymmetry breaking without the need for an additional
messenger sector. A reasonable choice of parameters leads to gaugino masses of
the right order. Finally, we speculate that the entire ``ISS x SM'' model
should be interpreted as a magnetic dual of an (unknown) asymptotically free
theory.
| [
{
"created": "Thu, 19 Jul 2007 19:48:00 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Nov 2007 16:14:15 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Abel",
"Steven",
""
],
[
"Durnford",
"Callum",
""
],
[
"Jaeckel",
"Joerg",
""
],
[
"Khoze",
"Valentin V.",
""
]
] | We consider the metastable N=1 QCD model of Intriligator, Seiberg and Shih (ISS), deformed by adding a baryon term to the superpotential. This simple deformation causes the spontaneous breaking of the approximate R-symmetry of the metastable vacuum. We then gauge the flavour SU(5)_f and identify it with the parent gauge symmetry of the Standard Model (SM). This implements direct mediation of supersymmetry breaking without the need for an additional messenger sector. A reasonable choice of parameters leads to gaugino masses of the right order. Finally, we speculate that the entire ``ISS x SM'' model should be interpreted as a magnetic dual of an (unknown) asymptotically free theory. |
hep-ph/9801223 | Yates Andrew | Andrew Yates and Wojciech H. Zurek | Vortex formation in two dimensions: When symmetry breaks, how big are
the pieces? | 5 pages, 4 postscript figures, uses RevTex and epsf.sty | Phys.Rev.Lett. 80 (1998) 5477-5480 | 10.1103/PhysRevLett.80.5477 | null | hep-ph astro-ph cond-mat | null | We investigate the dynamics of second order phase transitions in two
dimensions, breaking a gauged U(1) symmetry. Using numerical simulations, we
show that the density of topological defects formed scales with the quench
timescale $\tau_Q$ as $n \sim \tau_Q^{-1/2}$ when the dynamics is overdamped at
the instant when the freezeout of thermal fluctuations takes place, and $n \sim
\tau_Q^{-2/3}$ in the underdamped case. This is predicted by the scenario
proposed by one of us [1].
| [
{
"created": "Tue, 6 Jan 1998 16:05:38 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Yates",
"Andrew",
""
],
[
"Zurek",
"Wojciech H.",
""
]
] | We investigate the dynamics of second order phase transitions in two dimensions, breaking a gauged U(1) symmetry. Using numerical simulations, we show that the density of topological defects formed scales with the quench timescale $\tau_Q$ as $n \sim \tau_Q^{-1/2}$ when the dynamics is overdamped at the instant when the freezeout of thermal fluctuations takes place, and $n \sim \tau_Q^{-2/3}$ in the underdamped case. This is predicted by the scenario proposed by one of us [1]. |
0711.2740 | Krzysztof Golec-Biernat | Krzysztof Golec-Biernat and Agnieszka Luszczak | Diffractive structure function F_L^D from fits with higher twist | 8 pages, 4 figures, presented at 12th International Conference on
Elastic and Diffractive Scattering: Forward Physics and QCD, Hamburg, DESY,
Germany, 21-25 May 2007 | null | null | null | hep-ph | null | We make predictions for the diffractive longitudinal structure function F_L^D
to be measured at HERA, based on DGLAP fits of diffractive parton distributions
with twist--4 contribution. This contribution describes diffractive qqbar
production from longitudinal photons and significantly changes predictions for
F_L^D obtained in pure DGLAP analyses.
| [
{
"created": "Sun, 18 Nov 2007 09:02:15 GMT",
"version": "v1"
}
] | 2007-11-20 | [
[
"Golec-Biernat",
"Krzysztof",
""
],
[
"Luszczak",
"Agnieszka",
""
]
] | We make predictions for the diffractive longitudinal structure function F_L^D to be measured at HERA, based on DGLAP fits of diffractive parton distributions with twist--4 contribution. This contribution describes diffractive qqbar production from longitudinal photons and significantly changes predictions for F_L^D obtained in pure DGLAP analyses. |
1805.09036 | Martin Rohrmoser | Martin Rohrmoser, Pol-Bernard Gossiaux, Thierry Gousset, J\"org
Aichelin | Discrimination of effective radiative and collisional in-medium
energy-loss models by their effects on angular jet structure | null | null | 10.5506/APhysPolB.49.1325 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Energy-loss studies of hard particle probes produced in heavy ion collisions
have often been used to get information on the interactions within the medium
of a quark-gluon plasma (QGP). However, with the study of in-medium energy-loss
of individual particles alone, it remains still ambiguous, whether the occured
decrease in particle energy is caused by predominantly radiative or collisional
energy-loss mechanisms. Focusing on the in-medium energy-loss of hard
jet-partons, we propose additional studies of the angular jet-structure as a
means to further constrain the energy-loss mechanisms.
| [
{
"created": "Wed, 23 May 2018 10:01:07 GMT",
"version": "v1"
}
] | 2018-08-01 | [
[
"Rohrmoser",
"Martin",
""
],
[
"Gossiaux",
"Pol-Bernard",
""
],
[
"Gousset",
"Thierry",
""
],
[
"Aichelin",
"Jörg",
""
]
] | Energy-loss studies of hard particle probes produced in heavy ion collisions have often been used to get information on the interactions within the medium of a quark-gluon plasma (QGP). However, with the study of in-medium energy-loss of individual particles alone, it remains still ambiguous, whether the occured decrease in particle energy is caused by predominantly radiative or collisional energy-loss mechanisms. Focusing on the in-medium energy-loss of hard jet-partons, we propose additional studies of the angular jet-structure as a means to further constrain the energy-loss mechanisms. |
1102.3122 | Anna-Zuzana Dubnickova | M.Belicka, S. Dubnicka, A.Z. Dubnickova and A. Liptaj | Rigorous pion electromagnetic form factor behavior in the space-like
region | 8 pages, 3 eps figures | Phys.Rev.C83:028201,2011 | 10.1103/PhysRevC.83.028201 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | New precise experimental information on $\sigma_{tot}(e^+e^- \to \pi^+
\pi^-)$ is transferred into the space-like region, by taking advantage of the
analyticity. As a result a rigorous pion electromagnetic form factor behavior
is obtained. The latter with some existing model predictions is compared.
| [
{
"created": "Tue, 15 Feb 2011 16:25:53 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Feb 2011 12:42:27 GMT",
"version": "v2"
}
] | 2011-02-25 | [
[
"Belicka",
"M.",
""
],
[
"Dubnicka",
"S.",
""
],
[
"Dubnickova",
"A. Z.",
""
],
[
"Liptaj",
"A.",
""
]
] | New precise experimental information on $\sigma_{tot}(e^+e^- \to \pi^+ \pi^-)$ is transferred into the space-like region, by taking advantage of the analyticity. As a result a rigorous pion electromagnetic form factor behavior is obtained. The latter with some existing model predictions is compared. |
0708.4167 | Xiang Liu | Xiang Liu | Understanding the newly observed Y(4008) by Belle | 4 pages, 5 figures. Typos corrected | Eur.Phys.J.C54:471-474,2008 | 10.1140/epjc/s10052-008-0551-4 | null | hep-ph hep-ex nucl-ex nucl-th | null | Very recently a new enhancement around 4.05 GeV was observed by Belle
experiment. In this short note, we discuss some possible assignments for this
enhancement, i.e. $\psi(3S)$ and $D^*\bar{D}^*$ molecular state. In these two
assignments, Y(4008) can decay into $J/\psi\pi^0\pi^0$ with comparable
branching ratio with that of $Y(4008)\to J/\psi\pi^+\pi^-$. Thus one suggests
high energy experimentalists to look for Y(4008) in $J/\psi\pi^0\pi^0$ channel.
Furthermore one proposes further experiments to search missing channel
$D\bar{D}$, $D\bar{D}^*+h.c.$ and especially $\chi_{cJ}\pi^+\pi^-\pi^0$ and
$\eta_c\pi^+\pi^-\pi^0$, which will be helpful to distinguish $\psi(3S)$ and
$D^*\bar{D}^*$ molecular state assignments for this new enhancement.
| [
{
"created": "Thu, 30 Aug 2007 15:03:18 GMT",
"version": "v1"
},
{
"created": "Fri, 31 Aug 2007 04:48:06 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Nov 2007 14:52:31 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Liu",
"Xiang",
""
]
] | Very recently a new enhancement around 4.05 GeV was observed by Belle experiment. In this short note, we discuss some possible assignments for this enhancement, i.e. $\psi(3S)$ and $D^*\bar{D}^*$ molecular state. In these two assignments, Y(4008) can decay into $J/\psi\pi^0\pi^0$ with comparable branching ratio with that of $Y(4008)\to J/\psi\pi^+\pi^-$. Thus one suggests high energy experimentalists to look for Y(4008) in $J/\psi\pi^0\pi^0$ channel. Furthermore one proposes further experiments to search missing channel $D\bar{D}$, $D\bar{D}^*+h.c.$ and especially $\chi_{cJ}\pi^+\pi^-\pi^0$ and $\eta_c\pi^+\pi^-\pi^0$, which will be helpful to distinguish $\psi(3S)$ and $D^*\bar{D}^*$ molecular state assignments for this new enhancement. |
hep-ph/0603064 | Klaus Werner | Klaus Werner | How Nuclear Diffuseness Affects RHIC Data | null | null | null | null | hep-ph astro-ph nucl-ex nucl-th | null | The fact that nuclei have diffuse surfaces (rather than being simple spheres)
has dramatic consequences on the interpretation of RHIC heavy-ion data.
The effect is quite small (but not negligible) for central collisions, but
gets increasingly important with decreasing centrality.
One may actually divide the collision zone into a central part ("core"), with
expected high energy densities, and a peripheral part ("corona"), with smaller
energy densities, more like in pp or pA collisions.
We will discuss that many complicated "features" observed at RHIC become
almost trivial after subtracting the corona background. We are focussing on
AuAu collisions at 200 GeV.
| [
{
"created": "Wed, 8 Mar 2006 20:56:37 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Mar 2006 21:35:55 GMT",
"version": "v2"
},
{
"created": "Fri, 10 Mar 2006 08:45:26 GMT",
"version": "v3"
}
] | 2016-04-26 | [
[
"Werner",
"Klaus",
""
]
] | The fact that nuclei have diffuse surfaces (rather than being simple spheres) has dramatic consequences on the interpretation of RHIC heavy-ion data. The effect is quite small (but not negligible) for central collisions, but gets increasingly important with decreasing centrality. One may actually divide the collision zone into a central part ("core"), with expected high energy densities, and a peripheral part ("corona"), with smaller energy densities, more like in pp or pA collisions. We will discuss that many complicated "features" observed at RHIC become almost trivial after subtracting the corona background. We are focussing on AuAu collisions at 200 GeV. |
hep-ph/9302293 | null | S. Wycech (Soltan Institute for Nuclear Studies, Warsaw, Poland) and
A.M. Green (Research Institute for Theoretical Physics, University of
Helsinki, Finland) | The Production of the Exotic Atoms $\pi^+\pi^-$, $K^+\pi^-$ and $K^+K^-$ | 20 pages Latex, Bib-sty included and 3 figures on request from AMG | Nucl.Phys. A562 (1993) 446-460 | 10.1016/0375-9474(93)90207-E | HU-TFT-93-9 | hep-ph | null | Estimates are made of the signals to be expected in the production of the
exotic atoms Pionium ($\pi^+\pi^-$), Kaonium ($K^+K^-$) and also $K^+\pi^-$ in
pp, pd and $e^+e^-$ reactions. Such experiments are now being undertaken or
contemplated at CELSIUS, COSY, Indiana and SATURNE.
| [
{
"created": "Tue, 23 Feb 1993 11:15:32 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Wycech",
"S.",
"",
"Soltan Institute for Nuclear Studies, Warsaw, Poland"
],
[
"Green",
"A. M.",
"",
"Research Institute for Theoretical Physics, University of\n Helsinki, Finland"
]
] | Estimates are made of the signals to be expected in the production of the exotic atoms Pionium ($\pi^+\pi^-$), Kaonium ($K^+K^-$) and also $K^+\pi^-$ in pp, pd and $e^+e^-$ reactions. Such experiments are now being undertaken or contemplated at CELSIUS, COSY, Indiana and SATURNE. |
hep-ph/9910401 | Jacek Rozynek | J. Rozynek, G.Wilk | A Model for the Parton Distribution in Nuclei | 8 pages, 1 figure, revised version to be published in Phys. Lett. B | Phys.Lett. B473 (2000) 167-171 | 10.1016/S0370-2693(99)01425-2 | null | hep-ph nucl-th | null | We have extended recently proposed model of parton distribution i nucleons to
the case of nucleons in nuclei.
| [
{
"created": "Tue, 19 Oct 1999 12:14:07 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Dec 1999 14:16:15 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Rozynek",
"J.",
""
],
[
"Wilk",
"G.",
""
]
] | We have extended recently proposed model of parton distribution i nucleons to the case of nucleons in nuclei. |
hep-ph/9808222 | Xavier Martin | X. Martin and P. Peter | Current-carrying string loop motion: Limits on the classical description
and shocks | 13 pages including 16 figures, submitted to Phys. Rev. D. Major
changes: the title changed, new figures were added, new physics was found,
the conclusions have changed. Overall, the article has doubled in size | null | null | DARC/99-12 | hep-ph astro-ph gr-qc | null | The dynamical evolution of superconducting cosmic strings is much more
complicated than that of simple Goto-Nambu strings. For this reason, there are
only a few known analytical solutions and no numerical ones. The goal of this
paper is to present numerical solutions for the dynamics of planar
superconducting cosmic string loops. In most cases, a purely dynamical approach
turns out to be insufficient to describe correctly the evolution of a loop due
mainly to the appearance of shocks when spacelike currents are present and
kinks for timelike currents, leading to yet unaccounted for quantum effects.
The consequences of the quantum effects are mostly unknown at this time because
the problem requires a dynamical field theory treatment. It is however likely
that ultimately the result will be massive radiation in the form of charge
carriers from the string.
| [
{
"created": "Tue, 4 Aug 1998 19:08:53 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Aug 1999 15:55:34 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Martin",
"X.",
""
],
[
"Peter",
"P.",
""
]
] | The dynamical evolution of superconducting cosmic strings is much more complicated than that of simple Goto-Nambu strings. For this reason, there are only a few known analytical solutions and no numerical ones. The goal of this paper is to present numerical solutions for the dynamics of planar superconducting cosmic string loops. In most cases, a purely dynamical approach turns out to be insufficient to describe correctly the evolution of a loop due mainly to the appearance of shocks when spacelike currents are present and kinks for timelike currents, leading to yet unaccounted for quantum effects. The consequences of the quantum effects are mostly unknown at this time because the problem requires a dynamical field theory treatment. It is however likely that ultimately the result will be massive radiation in the form of charge carriers from the string. |
hep-ph/0601037 | Susan Gardner | S. J. Brodsky, S. Gardner, D. S. Hwang | Discrete Symmetries on the Light Front and a General Relation Connecting
Nucleon Electric Dipole and Anomalous Magnetic Moments | 25 pages, 1 figure. Published version. Ref. added | Phys.Rev.D73:036007,2006 | 10.1103/PhysRevD.73.036007 | null | hep-ph nucl-ex nucl-th | null | We consider the electric dipole form factor, F_3(q^2), as well as the Dirac
and Pauli form factors, F_1(q^2) and F_2(q^2), of the nucleon in the
light-front formalism. We derive an exact formula for F_3(q^2) to complement
those known for F_1(q^2) and F_2(q^2). We derive the light-front representation
of the discrete symmetry transformations and show that time-reversal- and
parity-odd effects are captured by phases in the light-front wave functions. We
thus determine that the contributions to F_2(q^2) and F_3(q^2), Fock state by
Fock state, are related, independent of the fundamental mechanism through which
CP violation is generated. Our relation is not specific to the nucleon, but,
rather, is true of spin-1/2 systems in general, be they lepton or baryon. The
empirical values of the anomalous magnetic moments, in concert with empirical
bounds on the associated electric dipole moments, can better constrain theories
of CP violation. In particular, we find that the neutron and proton electric
dipole moments echo the isospin structure of the anomalous magnetic moments,
kappa^n ~ - kappa^p.
| [
{
"created": "Thu, 5 Jan 2006 15:10:13 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Feb 2006 19:13:57 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Brodsky",
"S. J.",
""
],
[
"Gardner",
"S.",
""
],
[
"Hwang",
"D. S.",
""
]
] | We consider the electric dipole form factor, F_3(q^2), as well as the Dirac and Pauli form factors, F_1(q^2) and F_2(q^2), of the nucleon in the light-front formalism. We derive an exact formula for F_3(q^2) to complement those known for F_1(q^2) and F_2(q^2). We derive the light-front representation of the discrete symmetry transformations and show that time-reversal- and parity-odd effects are captured by phases in the light-front wave functions. We thus determine that the contributions to F_2(q^2) and F_3(q^2), Fock state by Fock state, are related, independent of the fundamental mechanism through which CP violation is generated. Our relation is not specific to the nucleon, but, rather, is true of spin-1/2 systems in general, be they lepton or baryon. The empirical values of the anomalous magnetic moments, in concert with empirical bounds on the associated electric dipole moments, can better constrain theories of CP violation. In particular, we find that the neutron and proton electric dipole moments echo the isospin structure of the anomalous magnetic moments, kappa^n ~ - kappa^p. |
1212.5196 | Valery Lyubovitskij | Thomas Gutsche, Valery E. Lyubovitskij, Ivan Schmidt, Alfredo Vega | Chiral Symmetry Breaking and Meson Wave Functions in Soft-Wall AdS/QCD | 10 pages | Phys.Rev.D87:056001, 2013 | 10.1103/PhysRevD.87.056001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider mesons composed of light and heavy quarks and discuss the
construction of the corresponding meson wave functions in soft-wall AdS/QCD. We
specifically take care that constraints imposed by chiral symmetry breaking and
by the heavy quark limit are fulfilled. The main results are: i) the wave
functions of light mesons have a nontrivial dependence on the current quark
mass, which gives rise to a mass spectrum consistent with the one including
explicit breaking of chiral symmetry; ii) the wave functions of heavy-light
mesons generate their correct mass spectrum, the mass splittings of vector and
pseudoscalar states, and the correct scaling of leptonic decay constants f(Q
\bar q) \sim 1/sqrt(mQ); iii) the wave functions of heavy quarkonia produce
their correct mass spectrum and lead to a scaling behaviour of the leptonic
decay constants f(Q \bar Q) \sim sqrt(mQ) and f(c \bar b) \sim mc/sqrt(mb) at
mc << mb, consistent with potential models and QCD sum rules.
| [
{
"created": "Thu, 20 Dec 2012 19:17:08 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Mar 2013 16:40:52 GMT",
"version": "v2"
}
] | 2013-03-04 | [
[
"Gutsche",
"Thomas",
""
],
[
"Lyubovitskij",
"Valery E.",
""
],
[
"Schmidt",
"Ivan",
""
],
[
"Vega",
"Alfredo",
""
]
] | We consider mesons composed of light and heavy quarks and discuss the construction of the corresponding meson wave functions in soft-wall AdS/QCD. We specifically take care that constraints imposed by chiral symmetry breaking and by the heavy quark limit are fulfilled. The main results are: i) the wave functions of light mesons have a nontrivial dependence on the current quark mass, which gives rise to a mass spectrum consistent with the one including explicit breaking of chiral symmetry; ii) the wave functions of heavy-light mesons generate their correct mass spectrum, the mass splittings of vector and pseudoscalar states, and the correct scaling of leptonic decay constants f(Q \bar q) \sim 1/sqrt(mQ); iii) the wave functions of heavy quarkonia produce their correct mass spectrum and lead to a scaling behaviour of the leptonic decay constants f(Q \bar Q) \sim sqrt(mQ) and f(c \bar b) \sim mc/sqrt(mb) at mc << mb, consistent with potential models and QCD sum rules. |
hep-ph/9701251 | Orlando Panella | O. Panella (INFN-Perugia), C. Carimalo (College de France, Paris),
Y.N. Srivastava (Univ. of Perugia) and A. Widom (Northeasetern University,
Boston) | Neutrinoless Double Beta Decay with Composite Neutrinos | 26 pages, 3 figures. RevTex file and 3 postscript figures. Numerical
error corrected. This implies a slight change on the numerical results and in
the figures. The conclusions are not affected. Uses an updated experimental
input relative to the version to be published by the Physical Review D | Phys.Rev. D56 (1997) 5766-5775 | 10.1103/PhysRevD.56.5766 | LPC 97-02 (College de France, Paris) | hep-ph | null | We study in detail the contribution of heavy composite Majorana neutrinos to
neutrino-less double beta decay. Our analysis confirms the result of a previous
estimate by two of the authors. Excited neutrinos couple to the electroweak
gauge bosons through a magnetic type effective Lagrangian.
The relevant nuclear matrix element is related to matrix elements available
in the literature and current bounds on the half-life of neutrino-less double
beta decay are converted into bounds on the compositeness scale and/or the
heavy neutrino mass. Our bounds are of the same order of magnitude as those
available from accelerator experiments.
| [
{
"created": "Thu, 9 Jan 1997 10:50:44 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Sep 1997 13:33:17 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Panella",
"O.",
"",
"INFN-Perugia"
],
[
"Carimalo",
"C.",
"",
"College de France, Paris"
],
[
"Srivastava",
"Y. N.",
"",
"Univ. of Perugia"
],
[
"Widom",
"A.",
"",
"Northeasetern University,\n Boston"
]
] | We study in detail the contribution of heavy composite Majorana neutrinos to neutrino-less double beta decay. Our analysis confirms the result of a previous estimate by two of the authors. Excited neutrinos couple to the electroweak gauge bosons through a magnetic type effective Lagrangian. The relevant nuclear matrix element is related to matrix elements available in the literature and current bounds on the half-life of neutrino-less double beta decay are converted into bounds on the compositeness scale and/or the heavy neutrino mass. Our bounds are of the same order of magnitude as those available from accelerator experiments. |
1404.0745 | Chiu Man Ho | Chiu Man Ho and Stephen D. H. Hsu | Does the BICEP2 Observation of Cosmological Tensor Modes Imply an Era of
Nearly Planckian Energy Densities? | 4 pages, v3: version to appear in JHEP | JHEP 1407 (2014) 060 | 10.1007/JHEP07(2014)060 | null | hep-ph astro-ph.CO gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | BICEP2 observations, interpreted most simply, suggest an era of inflation
with energy densities of order ($10^{16}\, {\rm GeV})^4$, not far below the
Planck density. However, models of TeV gravity with large extra dimensions
might allow a very different interpretation involving much more modest energy
scales. We discuss the viability of inflation in such models, and conclude that
existing scenarios do not provide attractive alternatives to single field
inflation in four dimensions. Because the detection of tensor modes strengthens
our confidence that inflation occurred, it disfavors models of large extra
dimensions, at least for the moment.
| [
{
"created": "Thu, 3 Apr 2014 01:22:53 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Apr 2014 01:55:31 GMT",
"version": "v2"
},
{
"created": "Sat, 19 Jul 2014 23:43:33 GMT",
"version": "v3"
}
] | 2015-06-19 | [
[
"Ho",
"Chiu Man",
""
],
[
"Hsu",
"Stephen D. H.",
""
]
] | BICEP2 observations, interpreted most simply, suggest an era of inflation with energy densities of order ($10^{16}\, {\rm GeV})^4$, not far below the Planck density. However, models of TeV gravity with large extra dimensions might allow a very different interpretation involving much more modest energy scales. We discuss the viability of inflation in such models, and conclude that existing scenarios do not provide attractive alternatives to single field inflation in four dimensions. Because the detection of tensor modes strengthens our confidence that inflation occurred, it disfavors models of large extra dimensions, at least for the moment. |
1808.01979 | Sreemanti Chakraborti | Sreemanti Chakraborti and Poulose Poulose | Interplay of Scalar and Fermionic Components in a Multi-component Dark
Matter Scenario | 19 pages, 19 figures, appendix added, some minor corrections to main
text | Eur. Phys. J. C, 79 5 (2019) 420 | 10.1140/epjc/s10052-019-6933-y | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the multi-component dark matter (DM) scenario considered in a
simple extension of the standard model with an inert scalar doublet and a
singlet fermionic field providing the two DM candidates. The DM states are made
stable under the unbroken $Z_2\times Z_2'$ discrete symmetry. An additional
gauge singlet scalar field is introduced to facilitate the interaction of the
dark fermion with the visible sector. Presence of a charged fermionic field
having the same $Z_2$ charge as that of the inert scalar field allows exploring
the dark matter mass regions otherwise disallowed, like in the standard Inert
Doublet Model (IDM) scenarios. With these arrangements, it is shown that the
light DM scenario and the desert region in the intermediate mass range of DM in
the standard IDM case can be made compatible with the relic density bounds and
direct detection limits. Further, detailed parameter space study is carried out
keeping the coexistence of both the scalar and fermionic components in focus,
showing that sizable parameter space regions are available for the entire mass
range of $10\ \rm GeV \le M_{DM}\le 2000$ GeV.
| [
{
"created": "Mon, 6 Aug 2018 16:16:00 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Sep 2018 13:24:24 GMT",
"version": "v2"
},
{
"created": "Mon, 20 May 2019 12:10:07 GMT",
"version": "v3"
}
] | 2019-05-21 | [
[
"Chakraborti",
"Sreemanti",
""
],
[
"Poulose",
"Poulose",
""
]
] | We explore the multi-component dark matter (DM) scenario considered in a simple extension of the standard model with an inert scalar doublet and a singlet fermionic field providing the two DM candidates. The DM states are made stable under the unbroken $Z_2\times Z_2'$ discrete symmetry. An additional gauge singlet scalar field is introduced to facilitate the interaction of the dark fermion with the visible sector. Presence of a charged fermionic field having the same $Z_2$ charge as that of the inert scalar field allows exploring the dark matter mass regions otherwise disallowed, like in the standard Inert Doublet Model (IDM) scenarios. With these arrangements, it is shown that the light DM scenario and the desert region in the intermediate mass range of DM in the standard IDM case can be made compatible with the relic density bounds and direct detection limits. Further, detailed parameter space study is carried out keeping the coexistence of both the scalar and fermionic components in focus, showing that sizable parameter space regions are available for the entire mass range of $10\ \rm GeV \le M_{DM}\le 2000$ GeV. |
hep-ph/0406070 | Seung Woo Ham | S. W. Ham and S. K. OH | CP Violation in the Neutral Higgs Sector of a Non-minimal Supersymmetric
Standard Model with Multiple Higgs Singlets | 21 pages, 4figures, JKPS | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The possibility of CP violation is studied in the Higgs sector of a
supersymmetric standard model with multiple Higgs singlets. The tree-level
Lagrangian in this model is assumed to conserve the CP symmetry. We find that
CP violation is viable in this model at the one-loop level, in an explicit way,
if the radiative corrections from the third generation of quarks and squarks
are taken into account. In the presence of explicit CP violation, at the
one-loop level, the upper bound on the mass of the lightest neutral Higgs boson
and the productions of the neutral Higgs bosons via the Higgsstrahlung process
in high-energy $e^+e^-$ collisions are calculated. We find that the upper bound
on the mass of the lightest neutral Higgs boson increases as the number of
Higgs singlets increases in a regulated manner. The production cross sections
of the neutral Higgs bosons also show a reasonable increasing behavior with
respect to the number of Higgs singlets.
| [
{
"created": "Mon, 7 Jun 2004 05:44:25 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Aug 2009 16:42:46 GMT",
"version": "v2"
}
] | 2009-08-14 | [
[
"Ham",
"S. W.",
""
],
[
"OH",
"S. K.",
""
]
] | The possibility of CP violation is studied in the Higgs sector of a supersymmetric standard model with multiple Higgs singlets. The tree-level Lagrangian in this model is assumed to conserve the CP symmetry. We find that CP violation is viable in this model at the one-loop level, in an explicit way, if the radiative corrections from the third generation of quarks and squarks are taken into account. In the presence of explicit CP violation, at the one-loop level, the upper bound on the mass of the lightest neutral Higgs boson and the productions of the neutral Higgs bosons via the Higgsstrahlung process in high-energy $e^+e^-$ collisions are calculated. We find that the upper bound on the mass of the lightest neutral Higgs boson increases as the number of Higgs singlets increases in a regulated manner. The production cross sections of the neutral Higgs bosons also show a reasonable increasing behavior with respect to the number of Higgs singlets. |
hep-ph/9311223 | Geert Jan van Oldenborgh | Geert Jan van Oldenborgh | Unstable Particles and Gauge Invariance | 6 pages, 2 figures appended, needs axodraw,epsf. The whole ps file is
available with anonymous ftp from pss058.psi.ch in /pub/preprints/ as
unstablepart.ps[.Z]. Proceedings of the 3rd workshop for SI and AI in HEP,
Oberammergau, PSI-PR-93-19 | null | null | null | hep-ph | null | When computing the properties of reactions involving unstable charged
particles care has to be taken to use a gauge invariant amplitude. In this talk
we present methods to (automatically) obtain such an amplitude, both at the
tree level and in one-loop calculations, using only a minimal number of
diagrams. The numerical difference with gauge variant methods commonly used
will be discussed for the case of tree level W pair production.
| [
{
"created": "Thu, 4 Nov 1993 12:28:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"van Oldenborgh",
"Geert Jan",
""
]
] | When computing the properties of reactions involving unstable charged particles care has to be taken to use a gauge invariant amplitude. In this talk we present methods to (automatically) obtain such an amplitude, both at the tree level and in one-loop calculations, using only a minimal number of diagrams. The numerical difference with gauge variant methods commonly used will be discussed for the case of tree level W pair production. |
1806.08397 | Fabio Siringo | Fabio Siringo and Giorgio Comitini | The gluon propagator in linear covariant $R_\xi$ gauges | In this new version a typo has been corrected in Eq.(A11) | Phys. Rev. D 98, 034023 (2018) | 10.1103/PhysRevD.98.034023 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Explicit analytical expressions are derived for the gluon propagator in a
generic linear covariant $R_\xi$ gauge, by a screened massive expansion for the
exact Faddeev-Popov Lagrangian of pure Yang-Mills theory. At one-loop, if the
gauge invariance of the pole structure is enforced, the gluon dressing function
is entirely and uniquely determined, without any free parameter or external
input. The gluon propagator is found finite in the IR for any $\xi$, with a
slight decrease of its limit value when going from the Landau gauge ($\xi=0$)
towards the Feynman gauge ($\xi=1$). An excellent agreement is found with the
lattice in the range $0<\xi<0.5$ where the data are available.
| [
{
"created": "Thu, 21 Jun 2018 18:55:57 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Aug 2018 15:40:23 GMT",
"version": "v2"
},
{
"created": "Tue, 15 Oct 2019 17:03:40 GMT",
"version": "v3"
}
] | 2019-10-16 | [
[
"Siringo",
"Fabio",
""
],
[
"Comitini",
"Giorgio",
""
]
] | Explicit analytical expressions are derived for the gluon propagator in a generic linear covariant $R_\xi$ gauge, by a screened massive expansion for the exact Faddeev-Popov Lagrangian of pure Yang-Mills theory. At one-loop, if the gauge invariance of the pole structure is enforced, the gluon dressing function is entirely and uniquely determined, without any free parameter or external input. The gluon propagator is found finite in the IR for any $\xi$, with a slight decrease of its limit value when going from the Landau gauge ($\xi=0$) towards the Feynman gauge ($\xi=1$). An excellent agreement is found with the lattice in the range $0<\xi<0.5$ where the data are available. |
1802.09409 | Kimberley Keri Vos | Thomas Mannel and K. Keri Vos | Reparametrization Invariance and Partial Re-Summations of the Heavy
Quark Expansion | 22 pages | null | 10.1007/JHEP06(2018)115 | SI-HEP-2018-02, QFET-2018-01 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We extend existing work on reparametrization invariance (RPI) of the
heavy-quark expansion. We discuss the total rates of inclusive processes and
obtain results which have a manifest RPI and can be expressed through matrix
elements of operators and states defined in full QCD. This approach leads to a
partial re-summation of higher-order terms in the heavy-quark expansion and has
the advantage that the number of independent parameters is reduced.
| [
{
"created": "Mon, 26 Feb 2018 15:46:01 GMT",
"version": "v1"
}
] | 2018-08-01 | [
[
"Mannel",
"Thomas",
""
],
[
"Vos",
"K. Keri",
""
]
] | We extend existing work on reparametrization invariance (RPI) of the heavy-quark expansion. We discuss the total rates of inclusive processes and obtain results which have a manifest RPI and can be expressed through matrix elements of operators and states defined in full QCD. This approach leads to a partial re-summation of higher-order terms in the heavy-quark expansion and has the advantage that the number of independent parameters is reduced. |
hep-ph/9609251 | Laurel Sinclair | A. Lebedev, L. Sinclair, E. Strickland, J. Vazdik | Colour Coherence in Photon Induced Reactions | 6 pages, LaTeX, 6 eps figures included, to appear in the proceedings
of the workshop "Future Physics at HERA" | null | null | GLAS-PPE/96-05 | hep-ph | null | Colour coherence in hard photoproduction is considered using the Monte Carlo
event generators PYTHIA and HERWIG. Significant effects in the parton shower
are found using multijet observables for direct and resolved photon induced
reactions. The particle flow in the interjet region of direct processes shows a
strong influence of string fragmentation effects.
| [
{
"created": "Wed, 4 Sep 1996 20:53:42 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lebedev",
"A.",
""
],
[
"Sinclair",
"L.",
""
],
[
"Strickland",
"E.",
""
],
[
"Vazdik",
"J.",
""
]
] | Colour coherence in hard photoproduction is considered using the Monte Carlo event generators PYTHIA and HERWIG. Significant effects in the parton shower are found using multijet observables for direct and resolved photon induced reactions. The particle flow in the interjet region of direct processes shows a strong influence of string fragmentation effects. |
hep-ph/9801327 | Doris Jeanne Wagner | DJ Wagner and Thomas J. Weiler | Boxing with Neutrino Oscillations | 30 pages | Phys.Rev. D59 (1999) 113007 | 10.1103/PhysRevD.59.113007 | VAND-TH-98-01 | hep-ph | null | We develop a model-independent "box" parameterization of neutrino
oscillations. Oscillation probabilities are linear in these new parameters, so
measurements can straightforwardly determine the box parameters which can then
be manipulated to yield magnitudes of mixing matrix elements. We examine the
effects of unitarity On the box parameters and reduce the number of parameters
to the minimum set. Using the box algebra, we show that CP-violation may be
inferred from measurements of neutrino flavor mixing even when the oscillatory
factor has averaged. The framework presented here will facilitate general
analyses of neutrino oscillations among $n\ge 3$ flavors.
| [
{
"created": "Fri, 16 Jan 1998 13:57:22 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Wagner",
"DJ",
""
],
[
"Weiler",
"Thomas J.",
""
]
] | We develop a model-independent "box" parameterization of neutrino oscillations. Oscillation probabilities are linear in these new parameters, so measurements can straightforwardly determine the box parameters which can then be manipulated to yield magnitudes of mixing matrix elements. We examine the effects of unitarity On the box parameters and reduce the number of parameters to the minimum set. Using the box algebra, we show that CP-violation may be inferred from measurements of neutrino flavor mixing even when the oscillatory factor has averaged. The framework presented here will facilitate general analyses of neutrino oscillations among $n\ge 3$ flavors. |
hep-ph/9807435 | Genrel | Charanjit S. Aulakh, Michiyasu Nagasawa and Vikram Soni | A New Regime for Dense String Networks in the One Scale Model with
Friction | 5 pages, REVTEX. Version to appear in Physics Letters B | Phys.Lett.B471:13-19,1999 | 10.1016/S0370-2693(99)01243-5 | null | hep-ph | null | We examine the compatibility between the one scale model with friction for
the evolution of cosmic string networks with the Kibble mechanism for string
network formation during a second order phase transition. We find a regime
which connects (in a dramatically short time $\sim .1 t_c$) the dense string
network (small network scale $L\sim 1/T_c$) created by the Kibble
{\it{mechanism}} to the (dilute) Kibble {\it{regime}}(L\sim t^{3/4} in which
friction dominated strings remain till times $t_*\sim (M_P/T_c)^2t_c$. The
enormous loss of string length implied by this result is due to the continued
dissipative motion of the string network which follows from the one scale
model's identification of the typical curvature radius with the network scale
and the fact that the cosmological phase transition time $t_c\sim
M_{Planck}/T_c^2$ is much larger than the damping time scale $l_f\sim
T_c^2/T^3$. The significant implications for string mediated Baryogenisis are
also discussed briefly.
| [
{
"created": "Tue, 21 Jul 1998 05:12:14 GMT",
"version": "v1"
},
{
"created": "Sun, 29 Nov 1998 14:19:15 GMT",
"version": "v2"
},
{
"created": "Wed, 8 Dec 1999 15:49:28 GMT",
"version": "v3"
}
] | 2011-02-09 | [
[
"Aulakh",
"Charanjit S.",
""
],
[
"Nagasawa",
"Michiyasu",
""
],
[
"Soni",
"Vikram",
""
]
] | We examine the compatibility between the one scale model with friction for the evolution of cosmic string networks with the Kibble mechanism for string network formation during a second order phase transition. We find a regime which connects (in a dramatically short time $\sim .1 t_c$) the dense string network (small network scale $L\sim 1/T_c$) created by the Kibble {\it{mechanism}} to the (dilute) Kibble {\it{regime}}(L\sim t^{3/4} in which friction dominated strings remain till times $t_*\sim (M_P/T_c)^2t_c$. The enormous loss of string length implied by this result is due to the continued dissipative motion of the string network which follows from the one scale model's identification of the typical curvature radius with the network scale and the fact that the cosmological phase transition time $t_c\sim M_{Planck}/T_c^2$ is much larger than the damping time scale $l_f\sim T_c^2/T^3$. The significant implications for string mediated Baryogenisis are also discussed briefly. |
0903.4908 | Elena G. Ferreiro | E. G. Ferreiro, F. Fleuret, J. P. Lansberg and A. Rakotozafindrabe | Cold Nuclear Matter effects on J/\psi production at RHIC: comparing
shadowing models | 4 pages, 1 figure. Contribution to Rencontres de Moriond 2009: QCD
and High Energy Interactions | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a wide study on the comparison of different shadowing models and
their influence on \jpsi production. We have taken into account the possibility
of different partonic processes for the $c \bar c$-pair production. We notice
that the effect of shadowing corrections on \jpsi production clearly depends on
the partonic process considered. Our results are compared to the available data
on \dAu collisions at RHIC energies. We try different break up cross section
for each of the studied shadowing models.
| [
{
"created": "Fri, 27 Mar 2009 20:37:36 GMT",
"version": "v1"
}
] | 2009-03-31 | [
[
"Ferreiro",
"E. G.",
""
],
[
"Fleuret",
"F.",
""
],
[
"Lansberg",
"J. P.",
""
],
[
"Rakotozafindrabe",
"A.",
""
]
] | We present a wide study on the comparison of different shadowing models and their influence on \jpsi production. We have taken into account the possibility of different partonic processes for the $c \bar c$-pair production. We notice that the effect of shadowing corrections on \jpsi production clearly depends on the partonic process considered. Our results are compared to the available data on \dAu collisions at RHIC energies. We try different break up cross section for each of the studied shadowing models. |
1805.04230 | Alex Palameta | A. Palameta, D. Harnett, T. G. Steele | Meson-Hybrid Mixing in $J^{PC}=1^{++}$ Heavy Quarkonium from QCD
Sum-Rules | Updated citations and added figures in latest version | Phys. Rev. D 98, 074014 (2018) | 10.1103/PhysRevD.98.074014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore conventional meson-hybrid mixing in $J^{PC}=1^{++}$ heavy
quarkonium using QCD Laplace sum-rules. We calculate the cross-correlator
between a heavy conventional meson current and heavy hybrid current within the
operator product expansion, including terms proportional to the four- and
six-dimensional gluon condensates and the six-dimensional quark condensate.
Using experimentally determined hadron masses, we construct models of the
$1^{++}$ charmonium and bottomonium mass spectra. These models are used to
investigate which resonances couple to both currents and thus exhibit
conventional meson-hybrid mixing. In the charmonium sector, we find almost no
conventional meson-hybrid mixing in the $\chi_{c1}(1P)$, minimal mixing in the
$X(3872)$, and significant mixing in both the $X(4140)$ and $X(4274)$. In the
bottomonium sector, we find minimal conventional meson-hybrid mixing in the
$\chi_{b1}(1P)$ and significant mixing in both the $\chi_{b1}(2P)$ and
$\chi_{b1}(3P)$.
| [
{
"created": "Fri, 11 May 2018 02:50:08 GMT",
"version": "v1"
},
{
"created": "Fri, 18 May 2018 23:49:58 GMT",
"version": "v2"
},
{
"created": "Mon, 1 Oct 2018 21:06:07 GMT",
"version": "v3"
}
] | 2018-10-24 | [
[
"Palameta",
"A.",
""
],
[
"Harnett",
"D.",
""
],
[
"Steele",
"T. G.",
""
]
] | We explore conventional meson-hybrid mixing in $J^{PC}=1^{++}$ heavy quarkonium using QCD Laplace sum-rules. We calculate the cross-correlator between a heavy conventional meson current and heavy hybrid current within the operator product expansion, including terms proportional to the four- and six-dimensional gluon condensates and the six-dimensional quark condensate. Using experimentally determined hadron masses, we construct models of the $1^{++}$ charmonium and bottomonium mass spectra. These models are used to investigate which resonances couple to both currents and thus exhibit conventional meson-hybrid mixing. In the charmonium sector, we find almost no conventional meson-hybrid mixing in the $\chi_{c1}(1P)$, minimal mixing in the $X(3872)$, and significant mixing in both the $X(4140)$ and $X(4274)$. In the bottomonium sector, we find minimal conventional meson-hybrid mixing in the $\chi_{b1}(1P)$ and significant mixing in both the $\chi_{b1}(2P)$ and $\chi_{b1}(3P)$. |
1206.6497 | Avelino Vicente | Asmaa Abada, Debottam Das, Avelino Vicente and C\'edric Weiland | Enhancing lepton flavour violation in the supersymmetric inverse seesaw
beyond the dipole contribution | 29 pages, 9 figures, 4 tables; v2: minor corrections, version to
appear in JHEP | JHEP 1209 (2012) 015 | 10.1007/JHEP09(2012)015 | LPT-12-36 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In minimal supersymmetric models the $Z$-penguin usually provides
sub-dominant contributions to charged lepton flavour violating observables. In
this study, we consider the supersymmetric inverse seesaw in which the
non-minimal particle content allows for dominant contributions of the
$Z$-penguin to several lepton flavour violating observables. In particular, and
due to the low-scale (TeV) seesaw, the penguin contribution to, for instance,
$\Br(\mu \to 3e)$ and $\mu-e$ conversion in nuclei, allows to render some of
these observables within future sensitivity reach. Moreover, we show that in
this framework, the $Z$-penguin exhibits the same non-decoupling behaviour
which had previously been identified in flavour violating Higgs decays in the
Minimal Supersymmetric Standard Model.
| [
{
"created": "Wed, 27 Jun 2012 20:00:04 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Sep 2012 14:50:27 GMT",
"version": "v2"
}
] | 2015-06-05 | [
[
"Abada",
"Asmaa",
""
],
[
"Das",
"Debottam",
""
],
[
"Vicente",
"Avelino",
""
],
[
"Weiland",
"Cédric",
""
]
] | In minimal supersymmetric models the $Z$-penguin usually provides sub-dominant contributions to charged lepton flavour violating observables. In this study, we consider the supersymmetric inverse seesaw in which the non-minimal particle content allows for dominant contributions of the $Z$-penguin to several lepton flavour violating observables. In particular, and due to the low-scale (TeV) seesaw, the penguin contribution to, for instance, $\Br(\mu \to 3e)$ and $\mu-e$ conversion in nuclei, allows to render some of these observables within future sensitivity reach. Moreover, we show that in this framework, the $Z$-penguin exhibits the same non-decoupling behaviour which had previously been identified in flavour violating Higgs decays in the Minimal Supersymmetric Standard Model. |
hep-ph/0009126 | Martina Brisudova | M.M. Brisudova, L. Burakovsky, T. Goldman | Spectroscopy "windows" of quark-antiquark mesons and glueballs with
effective Regge trajectories | talk presented by MB at Quark Confinement and Hadron Spectrum IV,
Vienna, July 2000. To appear in the procceedings, requires sprocl.sty. 3
pages, 1 ps figure | null | null | null | hep-ph | null | Regge trajectories of quark-antiquark mesons can be well approximated for
phenomenology purposes by a specific nonlinear form, reflecting that the flux
tubes cannot be arbitrarily large, but break due to the effect of
pair-production. If confirmed, this would imply that there is only a finite
number of bound states on each trajectory, and consequently, an existence of
``spectroscopy windows'' for each flavor. Here we present our results for these
windows.
| [
{
"created": "Mon, 11 Sep 2000 15:43:03 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Brisudova",
"M. M.",
""
],
[
"Burakovsky",
"L.",
""
],
[
"Goldman",
"T.",
""
]
] | Regge trajectories of quark-antiquark mesons can be well approximated for phenomenology purposes by a specific nonlinear form, reflecting that the flux tubes cannot be arbitrarily large, but break due to the effect of pair-production. If confirmed, this would imply that there is only a finite number of bound states on each trajectory, and consequently, an existence of ``spectroscopy windows'' for each flavor. Here we present our results for these windows. |
2102.12490 | Benoit Laurent | James M. Cline, Avi Friedlander, Dong-Ming He, Kimmo Kainulainen,
Benoit Laurent, David Tucker-Smith | Baryogenesis and gravity waves from a UV-completed electroweak phase
transition | 29 pages, 10 figures; v2: GW spectrum corrected, conclusions changed,
references added | Phys. Rev. D 103, 123529 (2021) | 10.1103/PhysRevD.103.123529 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study gravity wave production and baryogenesis at the electroweak phase
transition, in a real singlet scalar extension of the Standard Model, including
vector-like top partners to generate the CP violation needed for electroweak
baryogenesis (EWBG). The singlet makes the phase transition strongly
first-order through its coupling to the Higgs boson, and it spontaneously
breaks CP invariance through a dimension-5 contribution to the top quark mass
term, generated by integrating out the heavy top quark partners. We improve on
previous studies by incorporating updated transport equations, compatible with
large bubble wall velocities. The wall speed and thickness are computed
directly from the microphysical parameters rather than treating them as free
parameters, allowing for a first-principles computation of the baryon
asymmetry. The size of the CP-violating dimension-5 operator needed for EWBG is
constrained by collider, electroweak precision, and renormalization group
running constraints. We identify regions of parameter space that can produce
the observed baryon asymmetry or observable gravitational (GW) wave signals.
Contrary to standard lore, we find that for strong deflagrations, the
efficiencies of large baryon asymmetry production and strong GW signals can be
positively correlated. However we find the overall likelihood of observably
large GW signals to be smaller than estimated in previous studies. In
particular, only detonation-type transitions are predicted to produce
observably large gravitational waves.
| [
{
"created": "Wed, 24 Feb 2021 19:00:01 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Mar 2021 16:56:23 GMT",
"version": "v2"
}
] | 2021-06-16 | [
[
"Cline",
"James M.",
""
],
[
"Friedlander",
"Avi",
""
],
[
"He",
"Dong-Ming",
""
],
[
"Kainulainen",
"Kimmo",
""
],
[
"Laurent",
"Benoit",
""
],
[
"Tucker-Smith",
"David",
""
]
] | We study gravity wave production and baryogenesis at the electroweak phase transition, in a real singlet scalar extension of the Standard Model, including vector-like top partners to generate the CP violation needed for electroweak baryogenesis (EWBG). The singlet makes the phase transition strongly first-order through its coupling to the Higgs boson, and it spontaneously breaks CP invariance through a dimension-5 contribution to the top quark mass term, generated by integrating out the heavy top quark partners. We improve on previous studies by incorporating updated transport equations, compatible with large bubble wall velocities. The wall speed and thickness are computed directly from the microphysical parameters rather than treating them as free parameters, allowing for a first-principles computation of the baryon asymmetry. The size of the CP-violating dimension-5 operator needed for EWBG is constrained by collider, electroweak precision, and renormalization group running constraints. We identify regions of parameter space that can produce the observed baryon asymmetry or observable gravitational (GW) wave signals. Contrary to standard lore, we find that for strong deflagrations, the efficiencies of large baryon asymmetry production and strong GW signals can be positively correlated. However we find the overall likelihood of observably large GW signals to be smaller than estimated in previous studies. In particular, only detonation-type transitions are predicted to produce observably large gravitational waves. |
1810.12868 | Amin Abou Ibrahim | Amin Aboubrahim and Pran Nath | Naturalness, the Hyperbolic Branch and Prospects for the Observation of
Charged Higgs at High Luminosity LHC and 27 TeV LHC | 33 pages, six figures (Accepted for publication in PRD) | Phys. Rev. D 98, 095024 (2018) | 10.1103/PhysRevD.98.095024 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | One of the early criterion proposed for naturalness was a relatively small
Higgs mixing parameter $\mu$ with $\mu/M_Z$ order few. A relatively small $\mu$
may lead to heavier Higgs masses ($H^0, A, H^{\pm}$ in MSSM) which are
significantly lighter than other scalars such as squarks. Such a situation is
realized on the hyperbolic branch of radiative breaking of the electroweak
symmetry. In this analysis we construct supergravity unified models with
relatively small $\mu$ in the sense described above and discuss the search for
the charged Higgs boson $H^{\pm}$ at HL-LHC and HE-LHC where we also carry out
a relative comparison of the discovery potential of the two using the decay
channel $H^{\pm} \to \tau \nu$. It is shown that an analysis based on the
traditional linear cuts on signals and backgrounds is not very successful in
extracting the signal while, in contrast, machine learning techniques such as
boosted decision trees prove to be far more effective. Thus it is shown that
models not discoverable with the conventional cut analyses become discoverable
with machine learning techniques. Using boosted decision trees we consider
several benchmarks and analyze the potential for their $5\sigma$ discovery at
the 14 TeV HL-LHC and at 27 TeV HE-LHC. It is shown that while the ten
benchmarks considered with the charged Higgs boson mass in the range 373 GeV-
812 GeV are all discoverable at HE-LHC, only four of the ten with Higgs boson
masses in the range 373 GeV-470 GeV are discoverable at HL-LHC. Further, while
the model points discoverable at both HE-LHC and HL-LHC would require up to 7
years of running time at HL-LHC, they could all be discovered in a period of
few months at HE-LHC.
| [
{
"created": "Tue, 30 Oct 2018 17:14:49 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Nov 2018 20:03:58 GMT",
"version": "v2"
}
] | 2018-12-05 | [
[
"Aboubrahim",
"Amin",
""
],
[
"Nath",
"Pran",
""
]
] | One of the early criterion proposed for naturalness was a relatively small Higgs mixing parameter $\mu$ with $\mu/M_Z$ order few. A relatively small $\mu$ may lead to heavier Higgs masses ($H^0, A, H^{\pm}$ in MSSM) which are significantly lighter than other scalars such as squarks. Such a situation is realized on the hyperbolic branch of radiative breaking of the electroweak symmetry. In this analysis we construct supergravity unified models with relatively small $\mu$ in the sense described above and discuss the search for the charged Higgs boson $H^{\pm}$ at HL-LHC and HE-LHC where we also carry out a relative comparison of the discovery potential of the two using the decay channel $H^{\pm} \to \tau \nu$. It is shown that an analysis based on the traditional linear cuts on signals and backgrounds is not very successful in extracting the signal while, in contrast, machine learning techniques such as boosted decision trees prove to be far more effective. Thus it is shown that models not discoverable with the conventional cut analyses become discoverable with machine learning techniques. Using boosted decision trees we consider several benchmarks and analyze the potential for their $5\sigma$ discovery at the 14 TeV HL-LHC and at 27 TeV HE-LHC. It is shown that while the ten benchmarks considered with the charged Higgs boson mass in the range 373 GeV- 812 GeV are all discoverable at HE-LHC, only four of the ten with Higgs boson masses in the range 373 GeV-470 GeV are discoverable at HL-LHC. Further, while the model points discoverable at both HE-LHC and HL-LHC would require up to 7 years of running time at HL-LHC, they could all be discovered in a period of few months at HE-LHC. |
hep-ph/0202159 | Leonard S. Kisslinger | Leonard S. Kisslinger | Instanton Model of QCD Phase Transition Bubble Walls | 8 pages, 1 figure, revtex, revised to give more details of the model
and relationship to other recent research | null | null | null | hep-ph | null | Using the liquid instanton model continued into Minkowski space and modified
for finite temperature, the energy momentum tensor and the surface tension for
buble walls during the QCD phase transition are derived. The resulting surface
tension is in agreement with lattice calculations. Application to bubble
collisions is discussed.
| [
{
"created": "Fri, 15 Feb 2002 22:27:50 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Jan 2003 02:39:16 GMT",
"version": "v2"
},
{
"created": "Fri, 21 Mar 2003 22:08:06 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Kisslinger",
"Leonard S.",
""
]
] | Using the liquid instanton model continued into Minkowski space and modified for finite temperature, the energy momentum tensor and the surface tension for buble walls during the QCD phase transition are derived. The resulting surface tension is in agreement with lattice calculations. Application to bubble collisions is discussed. |
0810.5126 | Matthew Buckley | Lotty Ackerman, Matthew R. Buckley, Sean M. Carroll, and Marc
Kamionkowski | Dark Matter and Dark Radiation | 14 pages, 6 figures Updated equations and figures | null | 10.1103/PhysRevD.79.023519 | null | hep-ph astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the feasibility and astrophysical consequences of a new long-range
U(1) gauge field ("dark electromagnetism") that couples only to dark matter,
not to the Standard Model. The dark matter consists of an equal number of
positive and negative charges under the new force, but annihilations are
suppressed if the dark matter mass is sufficiently high and the dark
fine-structure constant $\hat\alpha$ is sufficiently small. The correct relic
abundance can be obtained if the dark matter also couples to the conventional
weak interactions, and we verify that this is consistent with particle-physics
constraints. The primary limit on $\hat\alpha$ comes from the demand that the
dark matter be effectively collisionless in galactic dynamics, which implies
$\hat\alpha \lesssim 10^{-4}$ for TeV-scale dark matter. These values are
easily compatible with constraints from structure formation and primordial
nucleosynthesis. We raise the prospect of interesting new plasma effects in
dark matter dynamics, which remain to be explored.
| [
{
"created": "Tue, 28 Oct 2008 20:09:06 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Dec 2008 04:46:05 GMT",
"version": "v2"
}
] | 2009-11-13 | [
[
"Ackerman",
"Lotty",
""
],
[
"Buckley",
"Matthew R.",
""
],
[
"Carroll",
"Sean M.",
""
],
[
"Kamionkowski",
"Marc",
""
]
] | We explore the feasibility and astrophysical consequences of a new long-range U(1) gauge field ("dark electromagnetism") that couples only to dark matter, not to the Standard Model. The dark matter consists of an equal number of positive and negative charges under the new force, but annihilations are suppressed if the dark matter mass is sufficiently high and the dark fine-structure constant $\hat\alpha$ is sufficiently small. The correct relic abundance can be obtained if the dark matter also couples to the conventional weak interactions, and we verify that this is consistent with particle-physics constraints. The primary limit on $\hat\alpha$ comes from the demand that the dark matter be effectively collisionless in galactic dynamics, which implies $\hat\alpha \lesssim 10^{-4}$ for TeV-scale dark matter. These values are easily compatible with constraints from structure formation and primordial nucleosynthesis. We raise the prospect of interesting new plasma effects in dark matter dynamics, which remain to be explored. |
hep-ph/0203210 | Apostolos Pilaftsis | Apostolos Pilaftsis | Gauge and Scheme Dependence of Mixing Matrix Renormalization | 31 pages, LaTeX, uses axodraw.sty | Phys.Rev. D65 (2002) 115013 | 10.1103/PhysRevD.65.115013 | MC-TH-2002-02 | hep-ph | null | We revisit the issue of mixing matrix renormalization in theories that
include Dirac or Majorana fermions. We show how a gauge-variant on-shell
renormalized mixing matrix can be related to a manifestly gauge-independent one
within a generalized ${\bar {\rm MS}}$ scheme of renormalization. This
scheme-dependent relation is a consequence of the fact that in any scheme of
renormalization, the gauge-dependent part of the mixing-matrix counterterm is
ultra-violet safe and has a pure dispersive form. Employing the unitarity
properties of the theory, we can successfully utilize the afore-mentioned
scheme-dependent relation to preserve basic global or local symmetries of the
bare Lagrangian through the entire process of renormalization. As an immediate
application of our study, we derive the gauge-independent renormalization-group
equations of mixing matrices in a minimal extension of the Standard Model with
isosinglet neutrinos.
| [
{
"created": "Thu, 21 Mar 2002 21:21:13 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Pilaftsis",
"Apostolos",
""
]
] | We revisit the issue of mixing matrix renormalization in theories that include Dirac or Majorana fermions. We show how a gauge-variant on-shell renormalized mixing matrix can be related to a manifestly gauge-independent one within a generalized ${\bar {\rm MS}}$ scheme of renormalization. This scheme-dependent relation is a consequence of the fact that in any scheme of renormalization, the gauge-dependent part of the mixing-matrix counterterm is ultra-violet safe and has a pure dispersive form. Employing the unitarity properties of the theory, we can successfully utilize the afore-mentioned scheme-dependent relation to preserve basic global or local symmetries of the bare Lagrangian through the entire process of renormalization. As an immediate application of our study, we derive the gauge-independent renormalization-group equations of mixing matrices in a minimal extension of the Standard Model with isosinglet neutrinos. |
1308.3635 | Chihiro Sasaki | Chihiro Sasaki, Igor Mishustin and Krzysztof Redlich | Implementation of chromomagnetic gluons in Yang-Mills thermodynamics | 6 pages, 4 figures, v2: typo corrected in Eq.(4.4), minor
modifications in the text, results unchanged | null | 10.1103/PhysRevD.89.014031 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the recent high-precision lattice data on Yang-Mills equations
of state, we propose an effective theory of SU(3) gluonic matter. The theory is
constructed based on the center and scale symmetries and their dynamical
breaking, so that the interplay between color-electric and color-magnetic
gluons is included coherently. We suggest, that the magnetic gluon condensate
changes its thermal behavior qualitatively above the critical temperature, as a
consequence of the matching to dimensionally-reduced magnetic theories. We
consider thermodynamics in the mean field approximation and discuss the
properties and interpretation of the trace anomaly.
| [
{
"created": "Fri, 16 Aug 2013 14:12:19 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Nov 2013 14:34:57 GMT",
"version": "v2"
}
] | 2015-06-16 | [
[
"Sasaki",
"Chihiro",
""
],
[
"Mishustin",
"Igor",
""
],
[
"Redlich",
"Krzysztof",
""
]
] | Motivated by the recent high-precision lattice data on Yang-Mills equations of state, we propose an effective theory of SU(3) gluonic matter. The theory is constructed based on the center and scale symmetries and their dynamical breaking, so that the interplay between color-electric and color-magnetic gluons is included coherently. We suggest, that the magnetic gluon condensate changes its thermal behavior qualitatively above the critical temperature, as a consequence of the matching to dimensionally-reduced magnetic theories. We consider thermodynamics in the mean field approximation and discuss the properties and interpretation of the trace anomaly. |
hep-ph/9612369 | Kumar Gupta | Debrupa Chakraverty, Triptesh De, Binayak Dutta-Roy and K. S. Gupta
(Saha Institute of Nuclear Physics, Calcutta, India) | Non-relativistic Model for the Semileptonic \Lambda_b \to \Lambda_c
Decay | 13 pages, plain Latex file | Mod.Phys.Lett. A12 (1997) 195-204 | 10.1142/S0217732397000194 | SINP-TNP/96-19 | hep-ph nucl-th | null | We calculate the decay width for $\Lambda_b \to \Lambda_c e {\bar \nu}$ in
the frame work of a nonrelativistic quark (NRQ) model of heavy baryons where
the light quarks play the role of spectators. Our calculation does not make an
explicit use of the heavy quark symmetry. The branching ratio for the above
process as calculated here agrees reasonably well with the experimental value.
| [
{
"created": "Mon, 16 Dec 1996 08:48:20 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Chakraverty",
"Debrupa",
"",
"Saha Institute of Nuclear Physics, Calcutta, India"
],
[
"De",
"Triptesh",
"",
"Saha Institute of Nuclear Physics, Calcutta, India"
],
[
"Dutta-Roy",
"Binayak",
"",
"Saha Institute of Nuclear Physics, Calcutta, India"
],
[
... | We calculate the decay width for $\Lambda_b \to \Lambda_c e {\bar \nu}$ in the frame work of a nonrelativistic quark (NRQ) model of heavy baryons where the light quarks play the role of spectators. Our calculation does not make an explicit use of the heavy quark symmetry. The branching ratio for the above process as calculated here agrees reasonably well with the experimental value. |
hep-ph/0407065 | Fawzi Boudjema | F. Boudjema, J. Fujimoto, T. Ishikawa, T. Kaneko, K. Kato, Y.
Kurihara, Y. Shimizu and Y. Yasui | Electroweak corrections to Higgs production through ZZ fusion at the
linear collider | 16 pages and 6 figures | Phys.Lett. B600 (2004) 65-76 | 10.1016/j.physletb.2004.08.062 | preprint numbers: KEK-CP-153, LAPTH-1049 and TMCP-04-03 | hep-ph | null | We present the full order alpha electroweak radiative corrections to e+e- ->
e+e-H. The computation is performed with the help of GRACE-loop. The extraction
of the full QED corrections is performed, these are quite large at threshold.
The genuine weak corrections, for the linear collider energies, when expressed
in the G_mu scheme are of order -2 to -4 for Higgs masses preferred by the
latest precision data. We also extract the m_t^2 type corrections and make a
comparison with the weak corrections for the process e+e- ->nu nu H.
| [
{
"created": "Tue, 6 Jul 2004 09:20:35 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Boudjema",
"F.",
""
],
[
"Fujimoto",
"J.",
""
],
[
"Ishikawa",
"T.",
""
],
[
"Kaneko",
"T.",
""
],
[
"Kato",
"K.",
""
],
[
"Kurihara",
"Y.",
""
],
[
"Shimizu",
"Y.",
""
],
[
"Yasui",
"Y.",
... | We present the full order alpha electroweak radiative corrections to e+e- -> e+e-H. The computation is performed with the help of GRACE-loop. The extraction of the full QED corrections is performed, these are quite large at threshold. The genuine weak corrections, for the linear collider energies, when expressed in the G_mu scheme are of order -2 to -4 for Higgs masses preferred by the latest precision data. We also extract the m_t^2 type corrections and make a comparison with the weak corrections for the process e+e- ->nu nu H. |
hep-ph/9906388 | Antonio Lopez Maroto | Antonio L. Maroto | Gravitino production during preheating | 10 pages, LaTeX, 2 figures. Talk given in the International Workshop
on Particles in Astrophysics and Cosmology, Valencia (Spain), May 3-8, 1999 | Nucl.Phys.Proc.Suppl.81:351-355,2000 | 10.1016/S0920-5632(99)00896-8 | null | hep-ph astro-ph hep-th | null | We study the production of gravitinos during the preheating era after
inflation by means of the non-perturbative Bogolyubov technique. Considering
only the helicity $\pm 3/2$ states, the problem is reduced to the simpler Dirac
fermions case. We calculate the production in a particular supergravity model
in an expanding universe and obtain the spectrum and number density. Finally we
compare the results with the nucleosynthesis bounds and extract some
consequences.
| [
{
"created": "Wed, 16 Jun 1999 10:15:20 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Maroto",
"Antonio L.",
""
]
] | We study the production of gravitinos during the preheating era after inflation by means of the non-perturbative Bogolyubov technique. Considering only the helicity $\pm 3/2$ states, the problem is reduced to the simpler Dirac fermions case. We calculate the production in a particular supergravity model in an expanding universe and obtain the spectrum and number density. Finally we compare the results with the nucleosynthesis bounds and extract some consequences. |
hep-ph/9407228 | V. Morgunov | B.V.Geshkenbein, V.L.Morgunov | A model calculation of the value of the electromagnetic coupling
constant at $q^2 = m_{Z}^{2}$ | in LaTeX, 6 pages, 0 figures, ITEP Preprint 49-94 | null | 10.1016/0370-2693(94)01324-1 | null | hep-ph | null | A QCD model with an infinite number of vector mesons suggested by one of the
authors is used to derive the value of the correction $\delta\alpha_{hadr}$ for
$\alpha(m_{Z}^{2})$ due to the strong interactions. The result is
$\delta\alpha_{hadr} = 0.0275(2)$ ; thus $\alpha(m^{2}_{Z}) =
(128.96(3))^{-1}$.
| [
{
"created": "Tue, 5 Jul 1994 18:05:00 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Geshkenbein",
"B. V.",
""
],
[
"Morgunov",
"V. L.",
""
]
] | A QCD model with an infinite number of vector mesons suggested by one of the authors is used to derive the value of the correction $\delta\alpha_{hadr}$ for $\alpha(m_{Z}^{2})$ due to the strong interactions. The result is $\delta\alpha_{hadr} = 0.0275(2)$ ; thus $\alpha(m^{2}_{Z}) = (128.96(3))^{-1}$. |
1404.3947 | Bogdan A. Dobrescu | Bogdan A. Dobrescu and Claudia Frugiuele | Hidden GeV-scale interactions of quarks | 5 pages; v2: Corrections in Eqs. (5), (6), and in Fig. 1 | Phys. Rev. Lett. 113, 061801 (2014) | 10.1103/PhysRevLett.113.061801 | FERMILAB-PUB-14-098-T | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore quark interactions mediated by new gauge bosons of masses in the
0.3 - 50 GeV range. A tight upper limit on the gauge coupling of light Z'
bosons is imposed by the anomaly cancellation conditions in conjunction with
collider bounds on new charged fermions. Limits from quarkonium decays are
model dependent, while electroweak constraints are mild. We derive the limits
for a Z' boson coupled to baryon number, and then construct a Z' model with
relaxed constraints, allowing quark couplings as large as 0.2 for a mass of a
few GeV.
| [
{
"created": "Tue, 15 Apr 2014 15:09:21 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Apr 2014 19:57:27 GMT",
"version": "v2"
}
] | 2014-08-13 | [
[
"Dobrescu",
"Bogdan A.",
""
],
[
"Frugiuele",
"Claudia",
""
]
] | We explore quark interactions mediated by new gauge bosons of masses in the 0.3 - 50 GeV range. A tight upper limit on the gauge coupling of light Z' bosons is imposed by the anomaly cancellation conditions in conjunction with collider bounds on new charged fermions. Limits from quarkonium decays are model dependent, while electroweak constraints are mild. We derive the limits for a Z' boson coupled to baryon number, and then construct a Z' model with relaxed constraints, allowing quark couplings as large as 0.2 for a mass of a few GeV. |
2310.08272 | Wen-Yuan Ai | Wen-Yuan Ai, Ankit Beniwal, Angelo Maggi and David J. E. Marsh | From QFT to Boltzmann: Freeze-in in the presence of oscillating
condensates | 40 pages, 3 figures; v2: refs updated, minor changes, to match the
published version; v3: (after publication) minor typos corrected | JHEP 02 (2024) 122 | 10.1007/JHEP02(2024)122 | KCL-PH-TH/2023-53 | hep-ph astro-ph.CO hep-th | http://creativecommons.org/licenses/by/4.0/ | Scalar dark matter (DM), and axions in particular, have an irreducible
abundance of particles produced by freeze-in due to portal interactions with
the Standard Model plasma in the early Universe. In addition, vacuum
misalignment and other mechanisms can lead to the presence of a cold,
oscillating condensate. Therefore, generically, the evolution of the DM in both
forms, condensate and particles, needs to be studied simultaneously. In
non-equilibrium quantum field theory, the condensate and particles are
described by one- and two-point functions, respectively. The fundamental
coupled equations of motion (EoMs) of these objects are non-local. To simplify
the EoMs and bring them into a familiar form for relic abundance calculations,
we perform a Markovianization process for a quasi-harmonically oscillating
homogeneous condensate, leading to local EoMs for the particle distribution
function and the envelope function of condensate oscillation. This reduces the
dynamics to a pair of coupled Boltzmann equations, and we derive explicitly the
form of the collision operators for all particle and condensate interactions.
| [
{
"created": "Thu, 12 Oct 2023 12:21:19 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Feb 2024 13:48:15 GMT",
"version": "v2"
},
{
"created": "Mon, 3 Jun 2024 20:48:11 GMT",
"version": "v3"
}
] | 2024-06-05 | [
[
"Ai",
"Wen-Yuan",
""
],
[
"Beniwal",
"Ankit",
""
],
[
"Maggi",
"Angelo",
""
],
[
"Marsh",
"David J. E.",
""
]
] | Scalar dark matter (DM), and axions in particular, have an irreducible abundance of particles produced by freeze-in due to portal interactions with the Standard Model plasma in the early Universe. In addition, vacuum misalignment and other mechanisms can lead to the presence of a cold, oscillating condensate. Therefore, generically, the evolution of the DM in both forms, condensate and particles, needs to be studied simultaneously. In non-equilibrium quantum field theory, the condensate and particles are described by one- and two-point functions, respectively. The fundamental coupled equations of motion (EoMs) of these objects are non-local. To simplify the EoMs and bring them into a familiar form for relic abundance calculations, we perform a Markovianization process for a quasi-harmonically oscillating homogeneous condensate, leading to local EoMs for the particle distribution function and the envelope function of condensate oscillation. This reduces the dynamics to a pair of coupled Boltzmann equations, and we derive explicitly the form of the collision operators for all particle and condensate interactions. |
1904.07513 | Sam Junius | Sam Junius, Laura Lopez-Honorez and Alberto Mariotti | A feeble window on leptophilic dark matter | 32 pages, 10 figures | JHEP 1907 (2019) 136 | 10.1007/JHEP07(2019)136 | ULB-TH/19-01 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we study a leptophilic dark matter scenario involving feeble
dark matter coupling to the Standard Model (SM) and compressed dark
matter-mediator mass spectrum. We consider a simplified model where the SM is
extended with one Majorana fermion, the dark matter, and one charged scalar,
the mediator, coupling to the SM leptons through a Yukawa interaction. We first
discuss the dependence of the dark matter relic abundance on the Yukawa
coupling going continuously from freeze-in to freeze-out with an intermediate
stage of conversion driven freeze-out. Focusing on the latter, we then exploit
the macroscopic decay length of the charged scalar to study the resulting
long-lived-particle signatures at collider and to explore the experimental
reach on the viable portion of the parameter space.
| [
{
"created": "Tue, 16 Apr 2019 07:49:05 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Sep 2019 08:01:57 GMT",
"version": "v2"
}
] | 2019-09-04 | [
[
"Junius",
"Sam",
""
],
[
"Lopez-Honorez",
"Laura",
""
],
[
"Mariotti",
"Alberto",
""
]
] | In this paper we study a leptophilic dark matter scenario involving feeble dark matter coupling to the Standard Model (SM) and compressed dark matter-mediator mass spectrum. We consider a simplified model where the SM is extended with one Majorana fermion, the dark matter, and one charged scalar, the mediator, coupling to the SM leptons through a Yukawa interaction. We first discuss the dependence of the dark matter relic abundance on the Yukawa coupling going continuously from freeze-in to freeze-out with an intermediate stage of conversion driven freeze-out. Focusing on the latter, we then exploit the macroscopic decay length of the charged scalar to study the resulting long-lived-particle signatures at collider and to explore the experimental reach on the viable portion of the parameter space. |
hep-ph/0004198 | Giacomo Morpurgo | G.Dillon and G.Morpurgo (Universita` di Genova and Istituto Nazionale
di Fisica nucleare,Genova,Italy) | On the miracle of the Coleman-Glashow and other baryon mass formulas | 12 pages,Latex | Phys.Lett.B481:239-244,2000; ERRATUM-ibid.B485:429,2000 | 10.1016/S0370-2693(00)00480-9 | INFN-GEF-TH-1/2000 | hep-ph | null | Due to a new measurement of the Xi(0) mass,the Coleman-Glashow formula for
the baryon octet e.m. masses (derived using unbroken SU(3) is satisfied to an
extraordinary level of precision.The same unexpected precision exists for the
Gell-Mann Okubo formula and for its octet-decuplet extension
(G.Morpurgo,Phys.Rev.Lett. 68(1992)139).We show that the old question "why do
they work so well?" is now answered by the general parameterization method.
| [
{
"created": "Thu, 20 Apr 2000 19:18:19 GMT",
"version": "v1"
}
] | 2011-02-01 | [
[
"Dillon",
"G.",
"",
"Universita` di Genova and Istituto Nazionale\n di Fisica nucleare,Genova,Italy"
],
[
"Morpurgo",
"G.",
"",
"Universita` di Genova and Istituto Nazionale\n di Fisica nucleare,Genova,Italy"
]
] | Due to a new measurement of the Xi(0) mass,the Coleman-Glashow formula for the baryon octet e.m. masses (derived using unbroken SU(3) is satisfied to an extraordinary level of precision.The same unexpected precision exists for the Gell-Mann Okubo formula and for its octet-decuplet extension (G.Morpurgo,Phys.Rev.Lett. 68(1992)139).We show that the old question "why do they work so well?" is now answered by the general parameterization method. |
hep-ph/9908252 | Santi Peris | M. Golterman (Wash.U. and UAB) and S. Peris (UAB) | The 7/11 rule: an estimate of m_rho/f_pi | 7 pages, 1 figure. Numerical error in scalar sector corrected; main
results unchanged | Phys.Rev.D61:034018,2000 | 10.1103/PhysRevD.61.034018 | UAB-FT-470 | hep-ph nucl-th | null | We derive an estimate for the ratio of the rho mass and the pion decay
constant from an analysis of vector and axial-vector two-point functions using
large-Nc, lowest-meson dominance and the operator product expansion, in the
chiral limit. We discuss the extension of this analysis to the scalar and
pseudoscalar sector. Furthermore, this leads to a successful parameter-free
determination of the L_i couplings of the chiral Lagrangian if an improved
Nambu-Jona-Lasinio ansatz for Green functions is assumed at low energies.
| [
{
"created": "Wed, 4 Aug 1999 13:11:49 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Sep 1999 14:09:27 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Golterman",
"M.",
"",
"Wash.U. and UAB"
],
[
"Peris",
"S.",
"",
"UAB"
]
] | We derive an estimate for the ratio of the rho mass and the pion decay constant from an analysis of vector and axial-vector two-point functions using large-Nc, lowest-meson dominance and the operator product expansion, in the chiral limit. We discuss the extension of this analysis to the scalar and pseudoscalar sector. Furthermore, this leads to a successful parameter-free determination of the L_i couplings of the chiral Lagrangian if an improved Nambu-Jona-Lasinio ansatz for Green functions is assumed at low energies. |
hep-ph/0412299 | Haruhiko Terao | Tatsuo Kobayashi (Kyoto U.), Hiroaki Shirano (Kanazawa U.), Haruhiko
Terao (Kanazawa U.) | Democratic mass matrices induced by strong gauge dynamics and large
mixing angles for leptons | 25 pages, 5 figures | null | 10.1143/PTP.113.1077 | KUNS-1948, KANAZAWA-04-19 | hep-ph | null | We consider dynamical realization of the democratic type Yukawa coupling
matrices as the Pendelton-Ross infrared fixed points.?Such fixed points of the
Yukawa couplings become possible by introducing many Higgs fields, which are
made superheavy but one massless mode. Explicitly, we consider a strongly
coupled GUT based on $SU(5) \times SU(5)$, where rapid convergence to the
infrared fixed point generates sufficiently large mass hierarchy for quarks and
leptons. Especially, it is found that the remarkable difference between mixing
angles in the quark and lepton sectors may be explained as a simple dynamical
consequence. We also discuss a possible scenario leading to the realistic mass
spectra and mixing angles for quarks and leptons. In this scheme, the Yukawa
couplings not only for top but also for bottom appear close to their
quasi-fixed points at low energy and, therefore, $\tan \beta$ should be large.
| [
{
"created": "Tue, 21 Dec 2004 00:22:17 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Kobayashi",
"Tatsuo",
"",
"Kyoto U."
],
[
"Shirano",
"Hiroaki",
"",
"Kanazawa U."
],
[
"Terao",
"Haruhiko",
"",
"Kanazawa U."
]
] | We consider dynamical realization of the democratic type Yukawa coupling matrices as the Pendelton-Ross infrared fixed points.?Such fixed points of the Yukawa couplings become possible by introducing many Higgs fields, which are made superheavy but one massless mode. Explicitly, we consider a strongly coupled GUT based on $SU(5) \times SU(5)$, where rapid convergence to the infrared fixed point generates sufficiently large mass hierarchy for quarks and leptons. Especially, it is found that the remarkable difference between mixing angles in the quark and lepton sectors may be explained as a simple dynamical consequence. We also discuss a possible scenario leading to the realistic mass spectra and mixing angles for quarks and leptons. In this scheme, the Yukawa couplings not only for top but also for bottom appear close to their quasi-fixed points at low energy and, therefore, $\tan \beta$ should be large. |
1301.2963 | Werner Rodejohann | Nina Memenga, Werner Rodejohann, He Zhang | A(4) Flavor Symmetry Model for Dirac-Neutrinos and Sizable U(e3) | 8 pages, 2 figures | Phys. Rev. D 87 (2013) 053021 | 10.1103/PhysRevD.87.053021 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Models based on flavor symmetries are the most often studied approaches to
explain the unexpected structure of lepton mixing. In many flavor symmetry
groups a product of two triplet representations contains a symmetric and an
anti-symmetric term. If this product of two triplets corresponds to a Majorana
mass term, then the anti-symmetric part vanishes, and in economic models
tri-bimaximal mixing is achieved. If neutrinos are Dirac particles, the
anti-symmetric part is however present and leads to deviations from
tri-bimaximal mixing, in particular non-zero U(e3). Thus, the non-vanishing
value of U(e3) and the nature of the neutrino are connected. We illustrate this
with a model based on A(4) within the framework of a neutrinophilic 2 Higgs
doublet scenario.
| [
{
"created": "Mon, 14 Jan 2013 13:06:11 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Apr 2013 08:26:25 GMT",
"version": "v2"
}
] | 2013-04-04 | [
[
"Memenga",
"Nina",
""
],
[
"Rodejohann",
"Werner",
""
],
[
"Zhang",
"He",
""
]
] | Models based on flavor symmetries are the most often studied approaches to explain the unexpected structure of lepton mixing. In many flavor symmetry groups a product of two triplet representations contains a symmetric and an anti-symmetric term. If this product of two triplets corresponds to a Majorana mass term, then the anti-symmetric part vanishes, and in economic models tri-bimaximal mixing is achieved. If neutrinos are Dirac particles, the anti-symmetric part is however present and leads to deviations from tri-bimaximal mixing, in particular non-zero U(e3). Thus, the non-vanishing value of U(e3) and the nature of the neutrino are connected. We illustrate this with a model based on A(4) within the framework of a neutrinophilic 2 Higgs doublet scenario. |
0910.1839 | Itay Yavin | Philip Schuster, Natalia Toro, Neal Weiner, and Itay Yavin | High Energy Electron Signals from Dark Matter Annihilation in the Sun | 6 pages, 5 figures, 1 table, clarifications added, published version | Phys.Rev.D82:115012,2010 | 10.1103/PhysRevD.82.115012 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we discuss two mechanisms by which high energy electrons
resulting from dark matter annihilations in or near the Sun can arrive at the
Earth. Specifically, electrons can escape the sun if DM annihilates into
long-lived states, or if dark matter scatters inelastically, which would leave
a halo of dark matter outside of the sun. Such a localized source of electrons
may affect the spectra observed by experiments with narrower fields of view
oriented towards the sun, such as ATIC, differently from those with larger
fields of view such as Fermi. We suggest a simple test of these possibilities
with existing Fermi data that is more sensitive than limits from final state
radiation. If observed, such a signal will constitute an unequivocal signature
of dark matter.
| [
{
"created": "Mon, 12 Oct 2009 19:53:09 GMT",
"version": "v1"
},
{
"created": "Sat, 11 Dec 2010 11:46:14 GMT",
"version": "v2"
}
] | 2010-12-23 | [
[
"Schuster",
"Philip",
""
],
[
"Toro",
"Natalia",
""
],
[
"Weiner",
"Neal",
""
],
[
"Yavin",
"Itay",
""
]
] | In this paper we discuss two mechanisms by which high energy electrons resulting from dark matter annihilations in or near the Sun can arrive at the Earth. Specifically, electrons can escape the sun if DM annihilates into long-lived states, or if dark matter scatters inelastically, which would leave a halo of dark matter outside of the sun. Such a localized source of electrons may affect the spectra observed by experiments with narrower fields of view oriented towards the sun, such as ATIC, differently from those with larger fields of view such as Fermi. We suggest a simple test of these possibilities with existing Fermi data that is more sensitive than limits from final state radiation. If observed, such a signal will constitute an unequivocal signature of dark matter. |
0805.0535 | Jin U Kang | Jin U Kang and Grigoris Panotopoulos | Dark matter in supersymmetric models with axino LSP in Randall-Sundrum
II brane model | 12 pages,3 figures, accepted in JHEP | JHEP 0805:036,2008 | 10.1088/1126-6708/2008/05/036 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The axino dark matter hypothesis in RSII brane model is studied. Within the
framework of CMSSM we assume that the lightest neutralino or stau is the NLSP,
and that the axino production has a single contribution from the NLSP decay. It
is found that the axino can play the role of dark matter in the universe and we
determine what the axino mass should be for different values of the
five-dimensional Planck mass. An upper bound is obtained for the latter
| [
{
"created": "Mon, 5 May 2008 14:01:33 GMT",
"version": "v1"
}
] | 2012-08-16 | [
[
"Kang",
"Jin U",
""
],
[
"Panotopoulos",
"Grigoris",
""
]
] | The axino dark matter hypothesis in RSII brane model is studied. Within the framework of CMSSM we assume that the lightest neutralino or stau is the NLSP, and that the axino production has a single contribution from the NLSP decay. It is found that the axino can play the role of dark matter in the universe and we determine what the axino mass should be for different values of the five-dimensional Planck mass. An upper bound is obtained for the latter |
1104.4505 | Gernot Eichmann | Gernot Eichmann | Nucleon electromagnetic form factors from the covariant Faddeev equation | 23 pages, 10 figures, 2 tables | Phys.Rev.D84:014014,2011 | 10.1103/PhysRevD.84.014014 | null | hep-ph hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the electromagnetic form factors of the nucleon in the
Poincare-covariant Faddeev framework based on the Dyson-Schwinger equations of
QCD. The general expression for a baryon's electromagnetic current in terms of
three interacting dressed quarks is derived. Upon employing a rainbow-ladder
gluon-exchange kernel for the quark-quark interaction, the nucleon's Faddeev
amplitude and electromagnetic form factors are computed without any further
truncations or model assumptions. The form factor results show clear evidence
of missing pion-cloud effects below a photon momentum transfer of ~2 GeV^2 and
in the chiral region whereas they agree well with experimental data at higher
photon momenta. Thus, the approach reflects the properties of the nucleon's
quark core.
| [
{
"created": "Fri, 22 Apr 2011 20:28:41 GMT",
"version": "v1"
}
] | 2011-08-08 | [
[
"Eichmann",
"Gernot",
""
]
] | We compute the electromagnetic form factors of the nucleon in the Poincare-covariant Faddeev framework based on the Dyson-Schwinger equations of QCD. The general expression for a baryon's electromagnetic current in terms of three interacting dressed quarks is derived. Upon employing a rainbow-ladder gluon-exchange kernel for the quark-quark interaction, the nucleon's Faddeev amplitude and electromagnetic form factors are computed without any further truncations or model assumptions. The form factor results show clear evidence of missing pion-cloud effects below a photon momentum transfer of ~2 GeV^2 and in the chiral region whereas they agree well with experimental data at higher photon momenta. Thus, the approach reflects the properties of the nucleon's quark core. |
hep-ph/0308124 | Shufang Su | Tom Farris, Heather E. Logan and Shufang Su | e+e- --> H+ e- nubar in the two-Higgs-doublet model | 14 pages, 13 figures; V2: minor changes in text, refs updated,
version to appear in PRD | Phys.Rev.D69:035005,2004 | 10.1103/PhysRevD.69.035005 | CALT-68-2448, MADPH-03-1342, UCD-03-09 | hep-ph | null | We calculate the cross section for e+e- --> H+ e- nubar in the
two-Higgs-doublet model from one-loop diagrams involving top and bottom quarks.
This process offers the possibility of producing the charged Higgs boson at the
e+e- collider when its mass is more than half the center-of-mass energy, so
that charged Higgs pair production is kinematically forbidden. The cross
section receives contributions from both s-channel and t-channel processes; the
s-channel contribution dominates for center-of-mass energies of 1 TeV and
below. About 80% of the s-channel contribution comes from the resonant process
e+e- --> H+ W-, with W- --> e- nubar. The cross section is generally small,
below 0.01 fb for tan beta > 2, and falls with increasing tan beta.
| [
{
"created": "Tue, 12 Aug 2003 16:48:15 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Jan 2004 23:51:01 GMT",
"version": "v2"
}
] | 2011-01-25 | [
[
"Farris",
"Tom",
""
],
[
"Logan",
"Heather E.",
""
],
[
"Su",
"Shufang",
""
]
] | We calculate the cross section for e+e- --> H+ e- nubar in the two-Higgs-doublet model from one-loop diagrams involving top and bottom quarks. This process offers the possibility of producing the charged Higgs boson at the e+e- collider when its mass is more than half the center-of-mass energy, so that charged Higgs pair production is kinematically forbidden. The cross section receives contributions from both s-channel and t-channel processes; the s-channel contribution dominates for center-of-mass energies of 1 TeV and below. About 80% of the s-channel contribution comes from the resonant process e+e- --> H+ W-, with W- --> e- nubar. The cross section is generally small, below 0.01 fb for tan beta > 2, and falls with increasing tan beta. |
hep-ph/0510179 | Claudio Coriano | Alessandro Cafarella, Claudio Coriano', Marco Guzzi and J. Smith | On the Scale Variation of the Total Cross Section for Higgs Production
at the LHC and at the Tevatron | 35 pages, 55 figures | Eur.Phys.J.C47:703-721,2006 | 10.1140/epjc/s2006-02608-5 | null | hep-ph | null | We present a detailed study of the total $p p$ cross section for scalar Higgs
production to next-to-next-to leading order in $\alpha_s$ at LHC energies, and
of the $p\bar p$ cross section at the Tevatron, combining an implementation of
the solutions of the parton evolution equations at the 3-loop order with the
corresponding hard scatterings, evaluated at the same perturbative order. Our
solutions of the DGLAP equations are implemented directly in $x$-space and
allow the study of the dependence of the results on the factorization ($\mu_F$)
and renormalization scales $(\mu_R)$ typical of a given process, together with
the stability of the perturbative expansion. The input sets for the parton
evolutions are those given by Martin, Roberts, Stirling and Thorne and by
Alekhin. Results for K-factors are also presented. The NNLO corrections can be
quite sizeable at typical collider energies. The stability region of the
perturbative expansion is found when $\mu_R > m_H\sim\mu_F$.
| [
{
"created": "Thu, 13 Oct 2005 16:17:53 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Oct 2005 07:57:05 GMT",
"version": "v2"
}
] | 2010-03-25 | [
[
"Cafarella",
"Alessandro",
""
],
[
"Coriano'",
"Claudio",
""
],
[
"Guzzi",
"Marco",
""
],
[
"Smith",
"J.",
""
]
] | We present a detailed study of the total $p p$ cross section for scalar Higgs production to next-to-next-to leading order in $\alpha_s$ at LHC energies, and of the $p\bar p$ cross section at the Tevatron, combining an implementation of the solutions of the parton evolution equations at the 3-loop order with the corresponding hard scatterings, evaluated at the same perturbative order. Our solutions of the DGLAP equations are implemented directly in $x$-space and allow the study of the dependence of the results on the factorization ($\mu_F$) and renormalization scales $(\mu_R)$ typical of a given process, together with the stability of the perturbative expansion. The input sets for the parton evolutions are those given by Martin, Roberts, Stirling and Thorne and by Alekhin. Results for K-factors are also presented. The NNLO corrections can be quite sizeable at typical collider energies. The stability region of the perturbative expansion is found when $\mu_R > m_H\sim\mu_F$. |
hep-ph/9710208 | Cristina Manuel | Cristina Manuel | Hard Thermal Loops and Chiral Lagrangians | 15 pages, Revtex, references added, typos corrected, final version to
appear in Phys. Rev. D | Phys.Rev. D57 (1998) 2871-2878 | 10.1103/PhysRevD.57.2871 | ECM-UB-PF-97/27 | hep-ph | null | Chiral symmetry is used as the guiding principle to derive hard thermal loop
effects in chiral perturbation theory. This is done by using a chiral invariant
background field method for the non-linear sigma model and the
Wess-Zumino-Witten lagrangian, with and without external vector and axial
vector sources. It is then shown that the n-point hard thermal loop is the
leading thermal correction for the Green function of n point vector soft quark
currents.
| [
{
"created": "Wed, 1 Oct 1997 13:44:29 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Dec 1997 11:49:07 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Manuel",
"Cristina",
""
]
] | Chiral symmetry is used as the guiding principle to derive hard thermal loop effects in chiral perturbation theory. This is done by using a chiral invariant background field method for the non-linear sigma model and the Wess-Zumino-Witten lagrangian, with and without external vector and axial vector sources. It is then shown that the n-point hard thermal loop is the leading thermal correction for the Green function of n point vector soft quark currents. |
hep-ph/9209272 | null | M. A. Nowak, M. Rho, I. Zahed | Chiral effective action with heavy quark symmetry | 14 pages, SUNY-NTG-92/27 | Phys.Rev. D48 (1993) 4370-4374 | 10.1103/PhysRevD.48.4370 | null | hep-ph | null | We derive an effective action combining chiral and heavy quark symmetry,
using approximate bosonization techniques of QCD. We explicitly show that the
heavy-quark limit is compatible with the large $N_c$ (number of color) limit in
the meson sector, and derive specific couplings between the light and heavy
mesons ($D$, $D^*$, ...) and their chiral partners. The relevance of this
effective action to solitons with heavy quarks describing heavy baryons is
discussed.
| [
{
"created": "Thu, 24 Sep 1992 00:10:40 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Nowak",
"M. A.",
""
],
[
"Rho",
"M.",
""
],
[
"Zahed",
"I.",
""
]
] | We derive an effective action combining chiral and heavy quark symmetry, using approximate bosonization techniques of QCD. We explicitly show that the heavy-quark limit is compatible with the large $N_c$ (number of color) limit in the meson sector, and derive specific couplings between the light and heavy mesons ($D$, $D^*$, ...) and their chiral partners. The relevance of this effective action to solitons with heavy quarks describing heavy baryons is discussed. |
1807.01154 | C. Pallis | C. Pallis | Unitarity-Safe Models of Non-Minimal Inflation in Supergravity | Published version; arXiv admin note: text overlap with
arXiv:1803.00349 | Eur.Phys.J. C78 (2018) no.12, 1014 | 10.1140/epjc/s10052-018-6485-6 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that models of chaotic inflation based on the phi^p potential and a
linear non-minimal coupling to gravity, fR=1+cR phi, can be done consistent
with data in the context of Supergravity, retaining the perturbative unitarity
up to the Planck scale, if we employ logarithmic Kahler potentials with
prefactors -p(1+n) or -p(n+1)-1, where -0.035<= n<=0.007 for p=2 or -0.0145<=
n<=0.006 for p=4. Focusing, moreover, on a model employing a gauge non-singlet
inflaton, we show that a solution to the mu problem of MSSM and baryogenesis
via non-thermal leptogensesis can be also accommodated.
| [
{
"created": "Sat, 30 Jun 2018 19:19:08 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Nov 2018 22:32:37 GMT",
"version": "v2"
},
{
"created": "Tue, 25 Dec 2018 05:23:56 GMT",
"version": "v3"
}
] | 2018-12-27 | [
[
"Pallis",
"C.",
""
]
] | We show that models of chaotic inflation based on the phi^p potential and a linear non-minimal coupling to gravity, fR=1+cR phi, can be done consistent with data in the context of Supergravity, retaining the perturbative unitarity up to the Planck scale, if we employ logarithmic Kahler potentials with prefactors -p(1+n) or -p(n+1)-1, where -0.035<= n<=0.007 for p=2 or -0.0145<= n<=0.006 for p=4. Focusing, moreover, on a model employing a gauge non-singlet inflaton, we show that a solution to the mu problem of MSSM and baryogenesis via non-thermal leptogensesis can be also accommodated. |
hep-ph/0012374 | Beata Ziaja | R. Peschanski, B. Ziaja | Factorial correlators: angular scaling within QCD jets | preprint SACLAY-T00-182, TSL/ISV-00-0239; 18 pages, latex, 4 figures;
submitted to Eur. Phys. J. C | Eur.Phys.J.C21:649-657,2001 | 10.1007/s100520100747 | null | hep-ph | null | Factorial correlators measure the amount of dynamical correlation in
multiplicity between two separated phase-space windows. We present the
analytical derivation of factorial correlators for a QCD jet described at the
double logarithmic (DL) accuracy. We obtain a new angular scaling property for
properly normalized correlators between two solid-angle cells or two rings
around the jet axis. Normalized QCD factorial correlators scale with the
angular distance and are independent of the window size. Scaling violations are
expected beyond DL approximation, in particular from the subjet structure.
Experimental tests are feasible, and thus welcome.
| [
{
"created": "Fri, 29 Dec 2000 13:39:36 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Jan 2001 16:32:49 GMT",
"version": "v2"
}
] | 2009-01-07 | [
[
"Peschanski",
"R.",
""
],
[
"Ziaja",
"B.",
""
]
] | Factorial correlators measure the amount of dynamical correlation in multiplicity between two separated phase-space windows. We present the analytical derivation of factorial correlators for a QCD jet described at the double logarithmic (DL) accuracy. We obtain a new angular scaling property for properly normalized correlators between two solid-angle cells or two rings around the jet axis. Normalized QCD factorial correlators scale with the angular distance and are independent of the window size. Scaling violations are expected beyond DL approximation, in particular from the subjet structure. Experimental tests are feasible, and thus welcome. |
hep-ph/0302154 | Fuminobu Takahashi | S. Kasuya, M. Kawasaki, Fuminobu Takahashi | Affleck-Dine mechanism with negative thermal logarithmic potential | 18 pages, RevTeX4, 9 postscript figures included, final version to
appear in Phys.Rev.D | Phys.Rev. D68 (2003) 023501 | 10.1103/PhysRevD.68.023501 | null | hep-ph astro-ph hep-th | null | We investigate whether the Affleck-Dine (AD) mechanism works when the
contribution of the two-loop thermal correction to the potential is negative in
the gauge-mediated supersymmetry breaking models. The AD field is trapped far
away from the origin by the negative thermal correction for a long time until
the temperature of the universe becomes low enough. The most striking feature
is that the Hubble parameter becomes much smaller than the mass scale of the
radial component of the AD field, during the trap. Then, the amplitude of the
AD field decreases so slowly that the baryon number is not fixed even after the
onset of radial oscillation. The resultant baryon asymmetry crucially depends
on whether the Hubble parameter, $H$, is larger than the mass scale of the
phase component of the AD field, $M_\theta$, at the beginning of oscillation.
If $H < M_\theta$ holds, the formation of Q balls plays an essential role to
determine the baryon number, which is found to be washed out due to the
nonlinear dynamics of Q-ball formation. On the other hand, if $H > M_\theta$
holds, it is found that the dynamics of Q-ball formation does not affect the
baryon asymmetry, and that it is possible to generate the right amount of the
baryon asymmetry.
| [
{
"created": "Tue, 18 Feb 2003 02:43:36 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Apr 2003 11:48:18 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Kasuya",
"S.",
""
],
[
"Kawasaki",
"M.",
""
],
[
"Takahashi",
"Fuminobu",
""
]
] | We investigate whether the Affleck-Dine (AD) mechanism works when the contribution of the two-loop thermal correction to the potential is negative in the gauge-mediated supersymmetry breaking models. The AD field is trapped far away from the origin by the negative thermal correction for a long time until the temperature of the universe becomes low enough. The most striking feature is that the Hubble parameter becomes much smaller than the mass scale of the radial component of the AD field, during the trap. Then, the amplitude of the AD field decreases so slowly that the baryon number is not fixed even after the onset of radial oscillation. The resultant baryon asymmetry crucially depends on whether the Hubble parameter, $H$, is larger than the mass scale of the phase component of the AD field, $M_\theta$, at the beginning of oscillation. If $H < M_\theta$ holds, the formation of Q balls plays an essential role to determine the baryon number, which is found to be washed out due to the nonlinear dynamics of Q-ball formation. On the other hand, if $H > M_\theta$ holds, it is found that the dynamics of Q-ball formation does not affect the baryon asymmetry, and that it is possible to generate the right amount of the baryon asymmetry. |
1008.4906 | Zhi-zhong Xing | Zhi-zhong Xing, Ye-Ling Zhou | A Generic Diagonalization of the 3X3 Neutrino Mass Matrix and Its
Implications on the mu-tau Flavor Symmetry and Maximal CP Violation | 11 pages. More discussions and references added. To appear in PLB | Phys.Lett.B693:584-590,2010 | 10.1016/j.physletb.2010.09.020 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the flavor basis where the mass eigenstates of three charged leptons are
identified with their flavor eigenstates, one may diagonalize a 3 X 3 Majorana
neutrino mass matrix M_nu by means of the standard parametrization of the 3 X 3
neutrino mixing matrix V. In this treatment the unphysical phases of M_nu have
to be carefully factored out, unless a special phase convention for neutrino
fields is chosen so as to simplify M_nu to M'_nu without any unphysical phases.
We choose this special flavor basis and establish some exact analytical
relations between the matrix elements of M'_nu M'_nu^dag and seven physical
parameters --- three neutrino masses (m_1, m_2, m_3), three flavor mixing
angles (theta_12, theta_13, theta_23) and the Dirac CP-violating phase (delta).
Such results allow us to derive the conditions for the mu-tau flavor symmetry
with theta_23 = pi/4 and maximal CP violation with delta = +/- pi/2, which
should be useful for discussing specific neutrino mass models. In particular,
we show that theta_23 = pi/4 and delta = +/- pi/2 keep unchanged when constant
matter effects are taken into account for a long-baseline neutrino oscillation
experiment.
| [
{
"created": "Sun, 29 Aug 2010 07:39:54 GMT",
"version": "v1"
},
{
"created": "Thu, 9 Sep 2010 08:50:56 GMT",
"version": "v2"
}
] | 2010-11-01 | [
[
"Xing",
"Zhi-zhong",
""
],
[
"Zhou",
"Ye-Ling",
""
]
] | In the flavor basis where the mass eigenstates of three charged leptons are identified with their flavor eigenstates, one may diagonalize a 3 X 3 Majorana neutrino mass matrix M_nu by means of the standard parametrization of the 3 X 3 neutrino mixing matrix V. In this treatment the unphysical phases of M_nu have to be carefully factored out, unless a special phase convention for neutrino fields is chosen so as to simplify M_nu to M'_nu without any unphysical phases. We choose this special flavor basis and establish some exact analytical relations between the matrix elements of M'_nu M'_nu^dag and seven physical parameters --- three neutrino masses (m_1, m_2, m_3), three flavor mixing angles (theta_12, theta_13, theta_23) and the Dirac CP-violating phase (delta). Such results allow us to derive the conditions for the mu-tau flavor symmetry with theta_23 = pi/4 and maximal CP violation with delta = +/- pi/2, which should be useful for discussing specific neutrino mass models. In particular, we show that theta_23 = pi/4 and delta = +/- pi/2 keep unchanged when constant matter effects are taken into account for a long-baseline neutrino oscillation experiment. |
1202.6339 | Hannes Roberts | Grant Larsen, Yasunori Nomura, Hannes L.L. Roberts | Supersymmetry with Light Stops | 27 pages, 7 figures | null | 10.1007/JHEP06(2012)032 | UCB-PTH-12/03 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent LHC data, together with the electroweak naturalness argument, suggest
that the top squarks may be significantly lighter than the other sfermions. We
present supersymmetric models in which such a split spectrum is obtained
through "geometries": being "close to" electroweak symmetry breaking implies
being "away from" supersymmetry breaking, and vice versa. In particular, we
present models in 5D warped spacetime, in which supersymmetry breaking and
Higgs fields are located on the ultraviolet and infrared branes, respectively,
and the top multiplets are localized to the infrared brane. The hierarchy of
the Yukawa matrices can be obtained while keeping near flavor degeneracy
between the first two generation sfermions, avoiding stringent constraints from
flavor and CP violation. Through the AdS/CFT correspondence, the models can be
interpreted as purely 4D theories in which the top and Higgs multiplets are
composites of some strongly interacting sector exhibiting nontrivial dynamics
at a low energy. Because of the compositeness of the Higgs and top multiplets,
Landau pole constraints for the Higgs and top couplings apply only up to the
dynamical scale, allowing for a relatively heavy Higgs boson, including m_h =
125 GeV as suggested by the recent LHC data. We analyze electroweak symmetry
breaking for a well-motivated subset of these models, and find that fine-tuning
in electroweak symmetry breaking is indeed ameliorated. We also discuss a flat
space realization of the scenario in which supersymmetry is broken by boundary
conditions, with the top multiplets localized to a brane while other matter
multiplets delocalized in the bulk.
| [
{
"created": "Tue, 28 Feb 2012 20:05:18 GMT",
"version": "v1"
}
] | 2015-06-04 | [
[
"Larsen",
"Grant",
""
],
[
"Nomura",
"Yasunori",
""
],
[
"Roberts",
"Hannes L. L.",
""
]
] | Recent LHC data, together with the electroweak naturalness argument, suggest that the top squarks may be significantly lighter than the other sfermions. We present supersymmetric models in which such a split spectrum is obtained through "geometries": being "close to" electroweak symmetry breaking implies being "away from" supersymmetry breaking, and vice versa. In particular, we present models in 5D warped spacetime, in which supersymmetry breaking and Higgs fields are located on the ultraviolet and infrared branes, respectively, and the top multiplets are localized to the infrared brane. The hierarchy of the Yukawa matrices can be obtained while keeping near flavor degeneracy between the first two generation sfermions, avoiding stringent constraints from flavor and CP violation. Through the AdS/CFT correspondence, the models can be interpreted as purely 4D theories in which the top and Higgs multiplets are composites of some strongly interacting sector exhibiting nontrivial dynamics at a low energy. Because of the compositeness of the Higgs and top multiplets, Landau pole constraints for the Higgs and top couplings apply only up to the dynamical scale, allowing for a relatively heavy Higgs boson, including m_h = 125 GeV as suggested by the recent LHC data. We analyze electroweak symmetry breaking for a well-motivated subset of these models, and find that fine-tuning in electroweak symmetry breaking is indeed ameliorated. We also discuss a flat space realization of the scenario in which supersymmetry is broken by boundary conditions, with the top multiplets localized to a brane while other matter multiplets delocalized in the bulk. |
2305.16547 | Qian Song | Ayres Freitas, Qian Song and Keping Xie | Fermionic Electroweak NNLO Corrections to $e^+ e^- \to ZH$ with
Polarized Beams and Different Renormalization Schemes | 6 pages, 2 figures and 3 tables | null | null | null | hep-ph | http://creativecommons.org/publicdomain/zero/1.0/ | Recently, the next-to-next-to-leading order (NNLO) electroweak corrections
with fermion loops to the Higgsstrahling process were computed. Here we present
numerical results for polarized electron/positron beams, as well as for two
input parameter schemes known as the $\alpha(0)$ and $G_\mu$ schemes. The size
of the NNLO corrections strongly depends on the beam polarization, leading to
an increase of the $ZH$ cross-section by 0.76% for $e^+_{\rm L} e^-_{\rm R}$
beams, and a decrease of 0.04% for $e^+_{\rm R} e^-_{\rm L}$ beams.
Furthermore, inclusion of the NNLO corrections is found to significantly reduce
the discrepancy between the results in the $\alpha(0)$ and $G_\mu$ schemes.
Using the remaining difference, together with other methods, the theory
uncertainty from missing bosonic electroweak corrections is estimated to be
less than 0.3%.
| [
{
"created": "Fri, 26 May 2023 00:15:23 GMT",
"version": "v1"
},
{
"created": "Tue, 30 May 2023 01:14:31 GMT",
"version": "v2"
}
] | 2023-05-31 | [
[
"Freitas",
"Ayres",
""
],
[
"Song",
"Qian",
""
],
[
"Xie",
"Keping",
""
]
] | Recently, the next-to-next-to-leading order (NNLO) electroweak corrections with fermion loops to the Higgsstrahling process were computed. Here we present numerical results for polarized electron/positron beams, as well as for two input parameter schemes known as the $\alpha(0)$ and $G_\mu$ schemes. The size of the NNLO corrections strongly depends on the beam polarization, leading to an increase of the $ZH$ cross-section by 0.76% for $e^+_{\rm L} e^-_{\rm R}$ beams, and a decrease of 0.04% for $e^+_{\rm R} e^-_{\rm L}$ beams. Furthermore, inclusion of the NNLO corrections is found to significantly reduce the discrepancy between the results in the $\alpha(0)$ and $G_\mu$ schemes. Using the remaining difference, together with other methods, the theory uncertainty from missing bosonic electroweak corrections is estimated to be less than 0.3%. |
hep-ph/0606068 | Tim M. P. Tait | Puneet Batra and Tim M.P. Tait | Measuring the W-t-b Interaction at the ILC | null | Phys.Rev.D74:054021,2006 | 10.1103/PhysRevD.74.054021 | ANL-HEP-PR-06-47 | hep-ph | null | The large top quark mass suggests that the top plays a pivotal role in
Electroweak symmetry-breaking dynamics and, as a result, may have modified
couplings to Electroweak bosons. Hadron colliders can provide measurements of
these couplings at the ~10% level, and one of the early expected triumphs of
the International Linear Collider is to reduce these uncertainties to the per
cent level. In this article, we propose the first direct measurement of the
Standard Model W-t-b coupling at the ILC, from measurements of t tbar-like
signals below the t tbar production threshold. We estimate that the ILC with
100 fb^{-1} can measure a combination of the coupling and top width to high
precision, and when combined with a direct measurement of the top width from
the above-threshold scan, results in a model-independent measurement of the
W-t-b interaction of the order of ~ 3%.
| [
{
"created": "Tue, 6 Jun 2006 20:58:52 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Batra",
"Puneet",
""
],
[
"Tait",
"Tim M. P.",
""
]
] | The large top quark mass suggests that the top plays a pivotal role in Electroweak symmetry-breaking dynamics and, as a result, may have modified couplings to Electroweak bosons. Hadron colliders can provide measurements of these couplings at the ~10% level, and one of the early expected triumphs of the International Linear Collider is to reduce these uncertainties to the per cent level. In this article, we propose the first direct measurement of the Standard Model W-t-b coupling at the ILC, from measurements of t tbar-like signals below the t tbar production threshold. We estimate that the ILC with 100 fb^{-1} can measure a combination of the coupling and top width to high precision, and when combined with a direct measurement of the top width from the above-threshold scan, results in a model-independent measurement of the W-t-b interaction of the order of ~ 3%. |
hep-ph/0011361 | Francesco Murgia | M. Anselmino (1), D. Boer (2), U. D'Alesio (3) and F. Murgia (3) ((1)
University and INFN, Torino, Italy, (2) RIKEN-BNL Research Center, (3)
University and INFN, Cagliari, Italy) | Spin effects in the fragmentation of transversely polarized and
unpolarized quarks | 5 pages + 2 eps figures, uses aipproc.sty and epsfig.sty. Talk
delivered by M. Anselmino at the "14th International Spin Physics Symposium",
SPIN2000, October 16-21, 2000, Osaka, Japan | null | 10.1063/1.1384123 | null | hep-ph | null | We study the fragmentation of a transversely polarized quark into a non
collinear (k_T not= 0) spinless hadron and the fragmentation of an unpolarized
quark into a non collinear transversely polarized spin 1/2 baryon. These
nonperturbative properties are described by spin and k_T dependent
fragmentation functions and are revealed in the observation of single spin
asymmetries. Recent data on the production of pions in polarized semi-inclusive
DIS and long known data on Lambda polarization in unpolarized p-N processes are
considered: these new fragmentation functions can describe the experimental
results and the single spin effects in the quark fragmentation turn out to be
surprisingly large.
| [
{
"created": "Wed, 29 Nov 2000 12:08:44 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Anselmino",
"M.",
""
],
[
"Boer",
"D.",
""
],
[
"D'Alesio",
"U.",
""
],
[
"Murgia",
"F.",
""
]
] | We study the fragmentation of a transversely polarized quark into a non collinear (k_T not= 0) spinless hadron and the fragmentation of an unpolarized quark into a non collinear transversely polarized spin 1/2 baryon. These nonperturbative properties are described by spin and k_T dependent fragmentation functions and are revealed in the observation of single spin asymmetries. Recent data on the production of pions in polarized semi-inclusive DIS and long known data on Lambda polarization in unpolarized p-N processes are considered: these new fragmentation functions can describe the experimental results and the single spin effects in the quark fragmentation turn out to be surprisingly large. |
hep-ph/9909450 | A. Khodjamirian | A. Khodjamirian | Pion Form Factors from QCD Light-Cone Sum Rules | 9 pages, 3 figures, Latex, epsfig, sprocl.sty, talk presented at the
6th INT/Jlab Workshop on Exclusive and Semiexclusive Processes at High
Momentum Transfer, Jefferson Laboratory, May 1999 | null | null | WUE-ITP-99-021 | hep-ph | null | Light-cone sum rules have proved to be very useful in calculating hadronic
matrix elements for exclusive processes. I present recent applications of this
method to the pion electromagnetic form factor and to the form factors of
$\gamma^* \rho \to \pi$ and $\gamma^*\gamma \to \pi^0$ transitions.
| [
{
"created": "Tue, 21 Sep 1999 10:44:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Khodjamirian",
"A.",
""
]
] | Light-cone sum rules have proved to be very useful in calculating hadronic matrix elements for exclusive processes. I present recent applications of this method to the pion electromagnetic form factor and to the form factors of $\gamma^* \rho \to \pi$ and $\gamma^*\gamma \to \pi^0$ transitions. |
hep-ph/0104031 | Mikko Laine | C.P. Korthals Altes, M. Laine | A remark on higher dimension induced domain wall defects in our world | 12 pages. Presentation clarified, references added; to appear in
Phys.Lett.B | Phys.Lett. B511 (2001) 269-275 | 10.1016/S0370-2693(01)00653-0 | null | hep-ph hep-th | null | There has been recent interest in new types of topological defects arising in
models with compact extra dimensions. We discuss in this context the old
statement that if only SU(N) gauge fields and adjoint matter live in the bulk,
and the coupling is weak, then the theory possesses a spontaneously broken
global Z(N) symmetry, with associated domain wall defects in four dimensions.
We discuss the behaviour of this symmetry at high temperatures. We argue that
the symmetry gets restored, so that cosmological domain wall production could
be used to constrain such models.
| [
{
"created": "Tue, 3 Apr 2001 12:22:09 GMT",
"version": "v1"
},
{
"created": "Mon, 14 May 2001 16:29:06 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Altes",
"C. P. Korthals",
""
],
[
"Laine",
"M.",
""
]
] | There has been recent interest in new types of topological defects arising in models with compact extra dimensions. We discuss in this context the old statement that if only SU(N) gauge fields and adjoint matter live in the bulk, and the coupling is weak, then the theory possesses a spontaneously broken global Z(N) symmetry, with associated domain wall defects in four dimensions. We discuss the behaviour of this symmetry at high temperatures. We argue that the symmetry gets restored, so that cosmological domain wall production could be used to constrain such models. |
hep-ph/9505319 | Naoya Hata | N. Hata, R. J. Scherrer, G. Steigman, D. Thomas, T. P. Walker, S.
Bludman, and P. Langacker | Big Bang Nucleosynthesis in Crisis? | To be published in Phys. Rev. Lett. Revised version to reflect
referee comments and criticisms by Copi, Schramm, and Turner of robustness of
D/He-3 analysis. Small quantitative changes but qualitative conclusions
unchanged. Question mark added to title. Entire ps file available at
ftp://upenn5.hep.upenn.edu/pub/hata/papers/bbn.ps.Z See also astro-ph/9412087 | Phys.Rev.Lett.75:3977-3980,1995 | 10.1103/PhysRevLett.75.3977 | OSU-TA-6/95, UPR-0654T | hep-ph astro-ph | null | A new evaluation of the constraint on the number of light neutrino species
(N_nu) from big bang nucleosynthesis suggests a discrepancy between the
predicted light element abundances and those inferred from observations, unless
the inferred primordial 4He abundance has been underestimated by 0.014 +/-
0.004 (1 sigma) or less than 10% (95%C.L.) of 3He survives stellar processing.
With the quoted systematic errors in the observed abundances and a conservative
chemical evolution parameterization, the best fit to the combined data is N_nu
= 2.1 +/- 0.3 (1 sigma) and the upper limit is N_nu < 2.6 (95% C.L.). The data
are inconsistent with the Standard Model (N_nu = 3) at the 98.6% C.L.
| [
{
"created": "Tue, 16 May 1995 18:17:43 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Nov 1995 19:53:13 GMT",
"version": "v2"
}
] | 2009-04-13 | [
[
"Hata",
"N.",
""
],
[
"Scherrer",
"R. J.",
""
],
[
"Steigman",
"G.",
""
],
[
"Thomas",
"D.",
""
],
[
"Walker",
"T. P.",
""
],
[
"Bludman",
"S.",
""
],
[
"Langacker",
"P.",
""
]
] | A new evaluation of the constraint on the number of light neutrino species (N_nu) from big bang nucleosynthesis suggests a discrepancy between the predicted light element abundances and those inferred from observations, unless the inferred primordial 4He abundance has been underestimated by 0.014 +/- 0.004 (1 sigma) or less than 10% (95%C.L.) of 3He survives stellar processing. With the quoted systematic errors in the observed abundances and a conservative chemical evolution parameterization, the best fit to the combined data is N_nu = 2.1 +/- 0.3 (1 sigma) and the upper limit is N_nu < 2.6 (95% C.L.). The data are inconsistent with the Standard Model (N_nu = 3) at the 98.6% C.L. |
1802.07688 | Simonetta Liuti | Simonetta Liuti, Michael Engelhardt and Abha Rajan | Generalized Wandzura Wilczek Relations and Orbital Angular Momentum | 5 pages, talk presented at QCD Evolution 2017, 22-16 May 2017,
Jefferson Lab, Newport News, VA-USA | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | New Lorentz Invariance Relations (LIRs) were presented between twist-three
Generalized Parton Distributions (GPDs) and transverse momentum, $k_T$, moments
of twist-two Generalized Transverse Momentum-Dependent Distributions (GTMDs).
By implementing both these LIRs and the QCD Equations of Motion in the quark
quark correlation function, we generated a new series of Wandzura Wilczek (WW)
relations in the off-forward sector. Two of these WW relations take on a
particularly interesting physical meaning in that they provide a clear
interpretation of the QCD structure of Orbital Angular Momentum (OAM) in the
nucleon. In particular, they provide a solution to the outstanding puzzle of
how OAM could be simultaneously described by twist-two GTMDs and twist-three
GPDs. Additional relations were discussed, in particular, for the helicity
configurations that can be detected analyzing specific spin asymmetries: one
corresponding to a longitudinally polarized quark in an unpolarized proton,
associated with spin-orbit correlations, and one for transverse proton
polarization, as a generalization of the relation obeyed by the $g_2$ structure
function; finally, we defined a relation connecting the off-forward extension
of the Sivers function to an off-forward Qiu-Sterman term.
| [
{
"created": "Wed, 21 Feb 2018 17:44:34 GMT",
"version": "v1"
}
] | 2018-02-22 | [
[
"Liuti",
"Simonetta",
""
],
[
"Engelhardt",
"Michael",
""
],
[
"Rajan",
"Abha",
""
]
] | New Lorentz Invariance Relations (LIRs) were presented between twist-three Generalized Parton Distributions (GPDs) and transverse momentum, $k_T$, moments of twist-two Generalized Transverse Momentum-Dependent Distributions (GTMDs). By implementing both these LIRs and the QCD Equations of Motion in the quark quark correlation function, we generated a new series of Wandzura Wilczek (WW) relations in the off-forward sector. Two of these WW relations take on a particularly interesting physical meaning in that they provide a clear interpretation of the QCD structure of Orbital Angular Momentum (OAM) in the nucleon. In particular, they provide a solution to the outstanding puzzle of how OAM could be simultaneously described by twist-two GTMDs and twist-three GPDs. Additional relations were discussed, in particular, for the helicity configurations that can be detected analyzing specific spin asymmetries: one corresponding to a longitudinally polarized quark in an unpolarized proton, associated with spin-orbit correlations, and one for transverse proton polarization, as a generalization of the relation obeyed by the $g_2$ structure function; finally, we defined a relation connecting the off-forward extension of the Sivers function to an off-forward Qiu-Sterman term. |
hep-ph/0412395 | Yara do Amaral Coutinho | F. M. L Almeida Jr, Y. A. Coutinho, J. A. Martins Sim\~oes, A. J.
Ramalho, S. Wulck, M. A. B. do Vale | On a $Z^{\prime}$ signature at next high energy electron-positron
colliders | 10 pages and 7 figures | Eur.Phys.J.C44:127-130,2005 | 10.1140/epjc/s2005-02339-1 | null | hep-ph | null | The associated production of a $Z^{\prime}$ and a final hard photon in high
energy electron-positron colliders is studied. It is shown that the hard photon
spectrum contains useful information on the $Z^{\prime}$ properties. This
remark suggests that, if a new neutral gauge boson exists for $M_{Z^{\prime}} <
\sqrt{s}$, it will not be necessary to make a new energy run at the
$Z^{\prime}$ mass in order to get most of its properties.
| [
{
"created": "Tue, 28 Dec 2004 11:10:14 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Feb 2005 17:30:41 GMT",
"version": "v2"
},
{
"created": "Fri, 8 Apr 2005 12:24:33 GMT",
"version": "v3"
}
] | 2009-01-07 | [
[
"Almeida",
"F. M. L",
"Jr"
],
[
"Coutinho",
"Y. A.",
""
],
[
"Simões",
"J. A. Martins",
""
],
[
"Ramalho",
"A. J.",
""
],
[
"Wulck",
"S.",
""
],
[
"Vale",
"M. A. B. do",
""
]
] | The associated production of a $Z^{\prime}$ and a final hard photon in high energy electron-positron colliders is studied. It is shown that the hard photon spectrum contains useful information on the $Z^{\prime}$ properties. This remark suggests that, if a new neutral gauge boson exists for $M_{Z^{\prime}} < \sqrt{s}$, it will not be necessary to make a new energy run at the $Z^{\prime}$ mass in order to get most of its properties. |
2009.04844 | Jean Cleymans | Jean Cleymans, Pok Man Lo, Krzysztof Redlich, Natasha Sharma | Multiplicity dependence of (multi-)strange baryons in the canonical
ensemble with phase shift corrections | 15 pages, 10 figures | Phys. Rev. C 103, 014904 (2021) | 10.1103/PhysRevC.103.014904 | CERN-TH-2020-141 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The increase in strangeness production with charged particle multiplicity, as
seen by the ALICE collaboration at CERN in p-p, p-Pb and Pb-Pb collisions, is
investigated in the hadron resonance gas model taking into account interactions
among hadrons using S-matrix corrections based on known phase shift analyses.
Strangeness conservation is taken into account in the framework of the
canonical strangeness ensemble. A very good description is obtained for the
variation of the strangeness content in the final state as a function of the
number of charged hadrons in the mid-rapidity region using the same fixed
temperature value as obtained in the most central Pb-Pb collisions. It is shown
that the number of charged hadrons is linearly proportional to the volume of
the system. For small multiplicities the canonical ensemble with local
strangeness conservation restricted to mid-rapidity leads to a stronger
suppression of (multi-)strange baryons than seen in the data. This is
compensated by introducing a global conservation of strangeness in the whole
phase-space which is parameterized by the canonical correlation volume larger
than the fireball volume at the mid-rapidity. The results on comparing the
hadron resonance gas model with and without S-matrix corrections, are presented
in detail. It is shown that the interactions introduced by the phase shift
analysis via the S-matrix formalism are essential for a better description of
the yields data.
| [
{
"created": "Thu, 10 Sep 2020 13:25:37 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Sep 2020 13:53:43 GMT",
"version": "v2"
},
{
"created": "Thu, 17 Sep 2020 08:18:11 GMT",
"version": "v3"
},
{
"created": "Sat, 26 Dec 2020 09:54:09 GMT",
"version": "v4"
}
] | 2021-01-27 | [
[
"Cleymans",
"Jean",
""
],
[
"Lo",
"Pok Man",
""
],
[
"Redlich",
"Krzysztof",
""
],
[
"Sharma",
"Natasha",
""
]
] | The increase in strangeness production with charged particle multiplicity, as seen by the ALICE collaboration at CERN in p-p, p-Pb and Pb-Pb collisions, is investigated in the hadron resonance gas model taking into account interactions among hadrons using S-matrix corrections based on known phase shift analyses. Strangeness conservation is taken into account in the framework of the canonical strangeness ensemble. A very good description is obtained for the variation of the strangeness content in the final state as a function of the number of charged hadrons in the mid-rapidity region using the same fixed temperature value as obtained in the most central Pb-Pb collisions. It is shown that the number of charged hadrons is linearly proportional to the volume of the system. For small multiplicities the canonical ensemble with local strangeness conservation restricted to mid-rapidity leads to a stronger suppression of (multi-)strange baryons than seen in the data. This is compensated by introducing a global conservation of strangeness in the whole phase-space which is parameterized by the canonical correlation volume larger than the fireball volume at the mid-rapidity. The results on comparing the hadron resonance gas model with and without S-matrix corrections, are presented in detail. It is shown that the interactions introduced by the phase shift analysis via the S-matrix formalism are essential for a better description of the yields data. |
1604.02029 | Mikael Chala | M. Chala, C. Grojean, M. Riembau and T. Vantalon | Deciphering the CP nature of the 750 GeV resonance | 9 pages, 11 figures. V2: matches published version | null | 10.1016/j.physletb.2016.06.050 | DESY 16-054 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The recently observed excess in diphoton events at around 750\,GeV can be
satisfactorily described in terms of a new spin-0 real singlet with effective
interactions to the gauge bosons. In this letter we first review the current
constraints on this setup. We further explore the production in association
with a gauge boson. We show the potential of this channel to unravel current
flat directions in the allowed parameter space. We then study the potential of
two different asymmetries for disentangling the CP nature of such a singlet in
both gluon fusion and vector-boson fusion. For this matter, we perform an
estimation of the efficiency for selecting signal and background events in
eight different decay modes, namely $4\ell, 2j\, 2\ell,
2j\ell\,E_T^\text{miss}, 2\gamma\,2j, 4\ell\,2j, 2\ell\,\gamma\,2j, 4j\,2\ell$
and $4j\,\ell\,E_T^\text{miss}$. We emphasize that the very different couplings
of this new singlet to the Standard Model particles as well as the larger mass
provide a distinctive phenomenology with respect to Higgs searches. We finally
show that a large region of the parameter space region could be tested within
the current LHC run, the dominant channel being $2\gamma\, 2j$.
| [
{
"created": "Thu, 7 Apr 2016 15:07:42 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Jul 2016 09:01:14 GMT",
"version": "v2"
}
] | 2016-07-22 | [
[
"Chala",
"M.",
""
],
[
"Grojean",
"C.",
""
],
[
"Riembau",
"M.",
""
],
[
"Vantalon",
"T.",
""
]
] | The recently observed excess in diphoton events at around 750\,GeV can be satisfactorily described in terms of a new spin-0 real singlet with effective interactions to the gauge bosons. In this letter we first review the current constraints on this setup. We further explore the production in association with a gauge boson. We show the potential of this channel to unravel current flat directions in the allowed parameter space. We then study the potential of two different asymmetries for disentangling the CP nature of such a singlet in both gluon fusion and vector-boson fusion. For this matter, we perform an estimation of the efficiency for selecting signal and background events in eight different decay modes, namely $4\ell, 2j\, 2\ell, 2j\ell\,E_T^\text{miss}, 2\gamma\,2j, 4\ell\,2j, 2\ell\,\gamma\,2j, 4j\,2\ell$ and $4j\,\ell\,E_T^\text{miss}$. We emphasize that the very different couplings of this new singlet to the Standard Model particles as well as the larger mass provide a distinctive phenomenology with respect to Higgs searches. We finally show that a large region of the parameter space region could be tested within the current LHC run, the dominant channel being $2\gamma\, 2j$. |
hep-ph/0203013 | T. L. Trueman | T.L. Trueman | Energy dependence of CNI analyzing power for proton-carbon scattering | RHIC Spin Note #1 | null | null | null | hep-ph | null | We use a simple Regge model to determine the energy dependence of the
analyzing power for pC scattering in the CNI region. We take the model of
Cudell et al which determines the Regge couplings and intercepts for the I=0,
non-flip Regge exchanges (Pomeron, f1 and \omega) and extend it to the
spin-flip amplitudes by allowing each of these exchanges to have independent
spin-flip factors tau_P, tau_f and tau_\omega. Using this we show that by
making measurments at two separate energies, with polarization known at one
energy, one can fix the ratios of the analyzing power at any energy. By making
an additional assumption that is reasonable, but not necessarily true, namely
tau_\omega=tau_f, we show that one can predict the energy dependence of the
analyzing power {using the existing E950 data}. We present the corresponding
predictions for beam energies of 100 GeV and 250 GeV protons on a fixed carbon
target based on a fit to the Spin 2000 data. Finally, we discuss the relation
of these results to the pp CNI analyzing power.
| [
{
"created": "Fri, 1 Mar 2002 21:17:24 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Trueman",
"T. L.",
""
]
] | We use a simple Regge model to determine the energy dependence of the analyzing power for pC scattering in the CNI region. We take the model of Cudell et al which determines the Regge couplings and intercepts for the I=0, non-flip Regge exchanges (Pomeron, f1 and \omega) and extend it to the spin-flip amplitudes by allowing each of these exchanges to have independent spin-flip factors tau_P, tau_f and tau_\omega. Using this we show that by making measurments at two separate energies, with polarization known at one energy, one can fix the ratios of the analyzing power at any energy. By making an additional assumption that is reasonable, but not necessarily true, namely tau_\omega=tau_f, we show that one can predict the energy dependence of the analyzing power {using the existing E950 data}. We present the corresponding predictions for beam energies of 100 GeV and 250 GeV protons on a fixed carbon target based on a fit to the Spin 2000 data. Finally, we discuss the relation of these results to the pp CNI analyzing power. |
1404.7714 | Stefan Groote Dr. | L. Kaldam\"ae and S. Groote | Virtual and real processes, the K\"all\'en function, and the relation to
dilogarithms | 12 pages, 5 figures, published version | J. Phys. G: Nucl. Part. Phys. 42 (2015) 085003 | 10.1088/0954-3899/42/8/085003 | MITP/14-032 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We enlighten relations between the K\"all\'en function, allowing in a simple
way to distinguish between virtual and real processes involving massive
particles, and the dilogarithms occurring as results of loop calculations for
such kind of processes.
| [
{
"created": "Wed, 30 Apr 2014 13:10:32 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Jul 2015 04:55:22 GMT",
"version": "v2"
}
] | 2015-07-15 | [
[
"Kaldamäe",
"L.",
""
],
[
"Groote",
"S.",
""
]
] | We enlighten relations between the K\"all\'en function, allowing in a simple way to distinguish between virtual and real processes involving massive particles, and the dilogarithms occurring as results of loop calculations for such kind of processes. |
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