id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2401.11350 | Lucas Kotz | Lucas Kotz | A study of experimental sensitivities to proton parton distributions
with xFitter | 13 pages, 13 figures, 1 table | null | null | SMU-PHY-23-07 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In collider physics, parton distribution functions (PDFs) play a crucial role
in computing theoretical cross sections for scattering reactions. This study
explores how different experimental data sets influence extracted PDFs in
CTEQ-TEA and MSHT NNLO PDF analyses. To gauge the impact of experimental data,
including the HERA and ZEUS combined charm and beauty production, LHCb 7 TeV
charm and beauty production, CMS 7 TeV W+c production, and CMS 13 TeV inclusive
jets, I utilize the $L_2$ sensitivity statistical indicator in the Hessian
framework as a visual representation of their respective impacts. This
sensitivity quantifies the statistical pulls on individual data sets against
the best-fit PDFs, facilitating the identification of tensions among competing
data sets. Using the QCD fitting framework xFitter, I extract the necessary
values for plotting $L_2$ sensitivities for ten distinct data sets implemented
in the program, employing recent PDF sets from the CTEQ-TEA and MSHT groups.
The computed $L_2$ sensitivities estimate the potential impact of the examined
data sets.
| [
{
"created": "Sun, 21 Jan 2024 00:13:07 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Feb 2024 20:58:17 GMT",
"version": "v2"
},
{
"created": "Wed, 5 Jun 2024 20:07:19 GMT",
"version": "v3"
}
] | 2024-06-07 | [
[
"Kotz",
"Lucas",
""
]
] | In collider physics, parton distribution functions (PDFs) play a crucial role in computing theoretical cross sections for scattering reactions. This study explores how different experimental data sets influence extracted PDFs in CTEQ-TEA and MSHT NNLO PDF analyses. To gauge the impact of experimental data, including the HERA and ZEUS combined charm and beauty production, LHCb 7 TeV charm and beauty production, CMS 7 TeV W+c production, and CMS 13 TeV inclusive jets, I utilize the $L_2$ sensitivity statistical indicator in the Hessian framework as a visual representation of their respective impacts. This sensitivity quantifies the statistical pulls on individual data sets against the best-fit PDFs, facilitating the identification of tensions among competing data sets. Using the QCD fitting framework xFitter, I extract the necessary values for plotting $L_2$ sensitivities for ten distinct data sets implemented in the program, employing recent PDF sets from the CTEQ-TEA and MSHT groups. The computed $L_2$ sensitivities estimate the potential impact of the examined data sets. |
hep-ph/9904271 | Yossi Nir | Yosef Nir | CP Violation in B Decays | 50 pages, 2 figures, LaTeX, lectures given at the school on Flavour
and Gauge Hierarchies, NATO Advanced Study Institute, Cargese, Corsica, July
20 - August 1, 1998, and at the First Particle Physics Winter School, KIAS,
Seoul, Korea, February 22 - 26, 1999 | null | null | WIS-99/15/Mar-DPP | hep-ph | null | In the near future, we will have the first significant experimental
measurements of CP violation in B decays. These measurements will easily test
crucial questions such as whether the Standard Model Kobayashi-Maskawa phase
plays a dominant role in CP violation or whether CP is an approximate symmetry
in nature. We explain the different types of CP violation in B decays, and the
usefulness of measuring them. We use the same formalism to describe the epsilon
and epsilon(prime) parameters of the neutral K system and to explain the terms
direct and indirect CP violation. We present the Standard Model predictions for
the various asymmetries. We argue that certain CP asymmetries in B decays are
subject to a very clean theoretical interpretation in terms of fundamental
Lagrangian parameters. Within the Standard Model, these asymmetries will
provide very accurate measurements of the CKM parameters. In case that
deviations from the Standard Model predictions will be found, there is enough
information to understand the nature of New Physics that is required to explain
them. We demonstrate this statement by analyzing the impact of various
Supersymmetric flavor models on CP violation.
| [
{
"created": "Thu, 8 Apr 1999 08:04:11 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Nir",
"Yosef",
""
]
] | In the near future, we will have the first significant experimental measurements of CP violation in B decays. These measurements will easily test crucial questions such as whether the Standard Model Kobayashi-Maskawa phase plays a dominant role in CP violation or whether CP is an approximate symmetry in nature. We explain the different types of CP violation in B decays, and the usefulness of measuring them. We use the same formalism to describe the epsilon and epsilon(prime) parameters of the neutral K system and to explain the terms direct and indirect CP violation. We present the Standard Model predictions for the various asymmetries. We argue that certain CP asymmetries in B decays are subject to a very clean theoretical interpretation in terms of fundamental Lagrangian parameters. Within the Standard Model, these asymmetries will provide very accurate measurements of the CKM parameters. In case that deviations from the Standard Model predictions will be found, there is enough information to understand the nature of New Physics that is required to explain them. We demonstrate this statement by analyzing the impact of various Supersymmetric flavor models on CP violation. |
1912.11326 | Ievgen Dubovyk Dr. | Ievgen Dubovyk, Janusz Gluza and Tord Riemann | Optimizing the Mellin-Barnes Approach to Numerical Multiloop
Calculations | Presented by I. Dubovyk at the XLIII International Conference of
Theoretical Physics "Matter to the Deepest", Chorz\'ow 2019 | Acta Physica Polonica B, Vol. 50 (2019), No 11, 1993 | 10.5506/APhysPolB.50.1993 | KW 19-009 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The status of numerical evaluations of Mellin-Barnes integrals is discussed,
in particular, the application of the quasi-Monte Carlo integration package QMC
to the efficient calculation of multi-dimensional integrals.
| [
{
"created": "Tue, 24 Dec 2019 12:54:03 GMT",
"version": "v1"
}
] | 2019-12-25 | [
[
"Dubovyk",
"Ievgen",
""
],
[
"Gluza",
"Janusz",
""
],
[
"Riemann",
"Tord",
""
]
] | The status of numerical evaluations of Mellin-Barnes integrals is discussed, in particular, the application of the quasi-Monte Carlo integration package QMC to the efficient calculation of multi-dimensional integrals. |
1304.2508 | Gautam Bhattacharyya | Gautam Bhattacharyya, Biplob Bhattacherjee, Tsutomu T. Yanagida,
Norimi Yokozaki | A natural scenario for heavy colored and light uncolored superpartners | v2: Clarifying remarks added in page 5, results and conclusions
unchanged, version to appear in Physics Letters B | null | 10.1016/j.physletb.2013.07.040 | SINP/TNP/2013/06, IPMU-13-0079 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Influenced by the current trend of experimental data, especially from the
LHC, we construct a supersymmetric scenario where a natural dynamics makes the
squarks and gluino super-heavy (order 10 TeV) while keeping the sleptons and
the weak gauginos light (100-500 GeV). The dynamics relies on the interfusion
of two underlying ideas: ($i$) gauge mediation of supersymmetry breaking with
two messenger multiplets, one transforming as a triplet of weak SU(2) and the
other as an octet of color SU(3); ($ii$) perturbative gauge coupling
unification at the string scale even with these incomplete SU(5) multiplets.
Interestingly, the relative magnitude of the triplet and octet messenger scales
that ensures gauge unification at the two-loop level also helps to naturally
keep the uncolored superpartners light while making the colored ones heavy.
| [
{
"created": "Tue, 9 Apr 2013 10:07:53 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Aug 2013 08:44:47 GMT",
"version": "v2"
}
] | 2015-06-15 | [
[
"Bhattacharyya",
"Gautam",
""
],
[
"Bhattacherjee",
"Biplob",
""
],
[
"Yanagida",
"Tsutomu T.",
""
],
[
"Yokozaki",
"Norimi",
""
]
] | Influenced by the current trend of experimental data, especially from the LHC, we construct a supersymmetric scenario where a natural dynamics makes the squarks and gluino super-heavy (order 10 TeV) while keeping the sleptons and the weak gauginos light (100-500 GeV). The dynamics relies on the interfusion of two underlying ideas: ($i$) gauge mediation of supersymmetry breaking with two messenger multiplets, one transforming as a triplet of weak SU(2) and the other as an octet of color SU(3); ($ii$) perturbative gauge coupling unification at the string scale even with these incomplete SU(5) multiplets. Interestingly, the relative magnitude of the triplet and octet messenger scales that ensures gauge unification at the two-loop level also helps to naturally keep the uncolored superpartners light while making the colored ones heavy. |
hep-ph/0205224 | Joel Giedt | Joel Giedt | Optical Unification | 9 pages, references added | Mod.Phys.Lett.A18:1625-1633,2003 | 10.1142/S0217732303011514 | LBNL-50358, UCB-PTH-02/23 | hep-ph hep-th | null | We discuss string scale unification facilitated by exotic matter with masses
at intermediate scales, between the observable sector supersymmetry breaking
scale and the string scale. We point out a mechanism by which string scale
unification may occur while producing a (lower) virtual unification scale
independent of the location of the intermediate scale and the value of the
string coupling. The apparent unification obtained by extrapolating low energy
gauge couplings is not accidental when this mechanism is invoked; virtual
unification is robust.
| [
{
"created": "Mon, 20 May 2002 21:54:49 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Jun 2002 20:48:35 GMT",
"version": "v2"
},
{
"created": "Fri, 23 Aug 2002 23:22:41 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Giedt",
"Joel",
""
]
] | We discuss string scale unification facilitated by exotic matter with masses at intermediate scales, between the observable sector supersymmetry breaking scale and the string scale. We point out a mechanism by which string scale unification may occur while producing a (lower) virtual unification scale independent of the location of the intermediate scale and the value of the string coupling. The apparent unification obtained by extrapolating low energy gauge couplings is not accidental when this mechanism is invoked; virtual unification is robust. |
hep-ph/9303248 | null | M. A. Doncheski and C. S. Kim | Associated $J/\psi + \gamma$ production as a probe of the polarized
gluon distribution | 16 pages (10 figures available from M.A.D.), MAD/PH/745, SNUTP 93-6,
YUMS 93-1 | Phys.Rev. D49 (1994) 4463-4468 | 10.1103/PhysRevD.49.4463 | null | hep-ph | null | Associated production of $J/\psi$ and a $\gamma$ has recently been proposed
as clean probe of the gluon distribution. The same mechanism can be used to
probe the polarized gluon content of the proton in polarized proton-proton
collisions. We study $J/\psi + \gamma$ production at both polarized fixed
target and polarized collider energies.
| [
{
"created": "Thu, 11 Mar 1993 20:32:48 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Doncheski",
"M. A.",
""
],
[
"Kim",
"C. S.",
""
]
] | Associated production of $J/\psi$ and a $\gamma$ has recently been proposed as clean probe of the gluon distribution. The same mechanism can be used to probe the polarized gluon content of the proton in polarized proton-proton collisions. We study $J/\psi + \gamma$ production at both polarized fixed target and polarized collider energies. |
hep-ph/0011170 | null | I. Hinchliffe (LBNL), N. Kersting (LBNL/UCB) | Flavor Alignment in SUSY GUTs | 20 pages, 1 figure | Phys.Rev.D63:115008,2001 | 10.1103/PhysRevD.63.115008 | LBNL-47091 | hep-ph | null | A Supersymmetric Grand unified model is constructed based on SO(10)xSO(10)
symmetry in which new types of Yukawa matrices couple standard and exotic
fermions. Evolution of these couplings from the Grand Unified scale to the
electroweak scale causes some of them to be driven to their fixed points. This
solves the supersymmetric alignment problem and ensures that there are no
observable flavor changing neutral currents mediated by supersymmetric
particles. Fermion hierarchy and neutrino mixing constraints are automatically
satisfied in this formalism.
| [
{
"created": "Mon, 13 Nov 2000 21:29:47 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Hinchliffe",
"I.",
"",
"LBNL"
],
[
"Kersting",
"N.",
"",
"LBNL/UCB"
]
] | A Supersymmetric Grand unified model is constructed based on SO(10)xSO(10) symmetry in which new types of Yukawa matrices couple standard and exotic fermions. Evolution of these couplings from the Grand Unified scale to the electroweak scale causes some of them to be driven to their fixed points. This solves the supersymmetric alignment problem and ensures that there are no observable flavor changing neutral currents mediated by supersymmetric particles. Fermion hierarchy and neutrino mixing constraints are automatically satisfied in this formalism. |
0811.3424 | Pavel Fileviez Perez | Pavel Fileviez Perez, Sogee Spinner | Spontaneous R-Parity Breaking and Left-Right Symmetry | 4 pages, minor corrections, title changed, to appear in Physics
Letters B | Phys.Lett.B673:251-254,2009 | 10.1016/j.physletb.2009.02.047 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by-nc-sa/3.0/ | We propose a simple renormalizable left-right theory where R-parity is
spontaneously broken and neutrino masses are generated through the Type I
seesaw mechanism and R-parity violation. In this theory R-parity and the gauge
symmetry are broken by the sneutrino vacuum expectation values and there is no
Majoron problem. The SU(2)_R and R-parity violation scales are determined by
the SUSY breaking scale making the model very predictive. We discuss the
spectrum and possible tests of the theory through the neutralinos, charginos,
Z^' and W_R decays at the Large Hadron Collider.
| [
{
"created": "Fri, 21 Nov 2008 17:59:47 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Feb 2009 21:53:22 GMT",
"version": "v2"
}
] | 2009-03-24 | [
[
"Perez",
"Pavel Fileviez",
""
],
[
"Spinner",
"Sogee",
""
]
] | We propose a simple renormalizable left-right theory where R-parity is spontaneously broken and neutrino masses are generated through the Type I seesaw mechanism and R-parity violation. In this theory R-parity and the gauge symmetry are broken by the sneutrino vacuum expectation values and there is no Majoron problem. The SU(2)_R and R-parity violation scales are determined by the SUSY breaking scale making the model very predictive. We discuss the spectrum and possible tests of the theory through the neutralinos, charginos, Z^' and W_R decays at the Large Hadron Collider. |
hep-ph/9808242 | Oleg Veretin | J. Fleischer (Bielefeld U.), A.V. Kotikov (JINR, Dubna), O.L. Veretin
(Bielefeld U.) | Analytic two-loop results for selfenergy- and vertex-type diagrams with
one non-zero mass | LaTeX, 27 pages + 3 ps figures, uses axodraw.sty, some references
revisted | Nucl.Phys.B547:343-374,1999 | 10.1016/S0550-3213(99)00078-4 | null | hep-ph | null | For a large class of two-loop selfenergy- and vertex-type diagrams with only
one non-zero mass ($M$) and the vertices also with only one non-zero external
momentum squared ($q^2$) the first few expansion coefficients are calculated by
the large mass expansion. This allows to `guess' the general structure of these
coefficients and to verify them in terms of certain classes of `basis
elements', which are essentially harmonic sums. Since for this case with only
one non-zero mass the large mass expansion and the Taylor series in terms of
$q^2$ are identical, this approach yields analytic expressions of the Taylor
coefficients, from which the diagram can be easily evaluated numerically in a
large domain of the complex $q^2-$plane by well known methods. It is also
possible to sum the Taylor series and present the results in terms of
polylogarithms.
| [
{
"created": "Thu, 6 Aug 1998 11:29:08 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Aug 1998 13:25:35 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Fleischer",
"J.",
"",
"Bielefeld U."
],
[
"Kotikov",
"A. V.",
"",
"JINR, Dubna"
],
[
"Veretin",
"O. L.",
"",
"Bielefeld U."
]
] | For a large class of two-loop selfenergy- and vertex-type diagrams with only one non-zero mass ($M$) and the vertices also with only one non-zero external momentum squared ($q^2$) the first few expansion coefficients are calculated by the large mass expansion. This allows to `guess' the general structure of these coefficients and to verify them in terms of certain classes of `basis elements', which are essentially harmonic sums. Since for this case with only one non-zero mass the large mass expansion and the Taylor series in terms of $q^2$ are identical, this approach yields analytic expressions of the Taylor coefficients, from which the diagram can be easily evaluated numerically in a large domain of the complex $q^2-$plane by well known methods. It is also possible to sum the Taylor series and present the results in terms of polylogarithms. |
2101.02718 | Antonio Enrique C\'arcamo Hern\'andez | A. E. C\'arcamo Hern\'andez, Ivan Schmidt | A renormalizable left-right symmetric model with low scale seesaw
mechanisms | Major improvements in leptogenesis section, new section on LFV,
discussions enlarged, new Figures and references added. 42 pages, 38 Figures.
Matches version to be published in NPB | null | 10.1016/j.nuclphysb.2022.115696 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a low scale renormalizable left-right symmetric theory that
successfully explains the observed SM fermion mass hierarchy, the tiny values
for the light active neutrino masses and is consistent with the lepton and
baryon asymmetries of the Universe, the muon and electron anomalous magnetic
moments as well as the with the constraints arising from the meson
oscillations. In the proposed model the top and exotic quarks obtain masses at
tree level, whereas the masses of the bottom, charm and strange quarks, tau and
muon leptons are generated from a tree level Universal Seesaw mechanism, thanks
to their mixings with the charged exotic vector like fermions. The masses for
the first generation SM charged fermions arise from a radiative seesaw
mechanism at one loop level, mediated by charged vector like fermions and
electrically neutral scalars. The light active neutrino masses are produced
from a one-loop level inverse seesaw mechanism mediated by electrically neutral
scalar singlets and right handed Majorana neutrinos. Our model is also
consistent with the experimental constraints arising from the Higgs diphoton
decay rate as well as with the constraints arising from charged lepton flavor
violation. We also discuss the $Z^{\prime }$ and heavy scalar production at a
proton-proton collider.
| [
{
"created": "Thu, 7 Jan 2021 19:00:05 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Sep 2021 14:32:57 GMT",
"version": "v2"
},
{
"created": "Mon, 7 Feb 2022 16:01:03 GMT",
"version": "v3"
}
] | 2022-03-02 | [
[
"Hernández",
"A. E. Cárcamo",
""
],
[
"Schmidt",
"Ivan",
""
]
] | We propose a low scale renormalizable left-right symmetric theory that successfully explains the observed SM fermion mass hierarchy, the tiny values for the light active neutrino masses and is consistent with the lepton and baryon asymmetries of the Universe, the muon and electron anomalous magnetic moments as well as the with the constraints arising from the meson oscillations. In the proposed model the top and exotic quarks obtain masses at tree level, whereas the masses of the bottom, charm and strange quarks, tau and muon leptons are generated from a tree level Universal Seesaw mechanism, thanks to their mixings with the charged exotic vector like fermions. The masses for the first generation SM charged fermions arise from a radiative seesaw mechanism at one loop level, mediated by charged vector like fermions and electrically neutral scalars. The light active neutrino masses are produced from a one-loop level inverse seesaw mechanism mediated by electrically neutral scalar singlets and right handed Majorana neutrinos. Our model is also consistent with the experimental constraints arising from the Higgs diphoton decay rate as well as with the constraints arising from charged lepton flavor violation. We also discuss the $Z^{\prime }$ and heavy scalar production at a proton-proton collider. |
1412.3133 | Sergio Scopetta | Matteo Rinaldi, Sergio Scopetta, Marco Traini, Vicente Vento | Double parton correlations in Light-Front constituent quark model | 8 pages, 12 figures, invited talk at the "XLIV ISMD Conference",
Bologna, Italy, 8-12 September 2014. Submitted to EPJ Web of Conferences | null | 10.1051/epjconf/20159002002 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Double parton distribution functions (dPDF) represent a tool to explore the
3D proton structure. They can be measured in high energy proton-proton and
proton nucleus collisions and encode information on how partons inside a proton
are correlated among each other. dPFDs are studied here in the valence quark
region, by means of a constituent quark model, where two particle correlations
are present without any additional prescription. This framework allows to
understand the dynamical origin of the correlations and to clarify which, among
the features of the results, are model independent. Use will be made of a
relativistic light-front scheme, able to overcome some drawbacks of the
previous calculation. Transverse momentum correlations, due to the exact
treatment of the boosts, are predicted and analyzed. The role of spin
correlations is also shown. Due to the covariance of the approach, some
symmetries of the dPDFs are seen unambigously. For the valence sector, the
study of the QCD evolution of the model results, which can be performed safely
thanks to the property of good support, has been also completed.
| [
{
"created": "Tue, 9 Dec 2014 21:59:20 GMT",
"version": "v1"
}
] | 2015-06-23 | [
[
"Rinaldi",
"Matteo",
""
],
[
"Scopetta",
"Sergio",
""
],
[
"Traini",
"Marco",
""
],
[
"Vento",
"Vicente",
""
]
] | Double parton distribution functions (dPDF) represent a tool to explore the 3D proton structure. They can be measured in high energy proton-proton and proton nucleus collisions and encode information on how partons inside a proton are correlated among each other. dPFDs are studied here in the valence quark region, by means of a constituent quark model, where two particle correlations are present without any additional prescription. This framework allows to understand the dynamical origin of the correlations and to clarify which, among the features of the results, are model independent. Use will be made of a relativistic light-front scheme, able to overcome some drawbacks of the previous calculation. Transverse momentum correlations, due to the exact treatment of the boosts, are predicted and analyzed. The role of spin correlations is also shown. Due to the covariance of the approach, some symmetries of the dPDFs are seen unambigously. For the valence sector, the study of the QCD evolution of the model results, which can be performed safely thanks to the property of good support, has been also completed. |
hep-ph/0703316 | Pietro Colangelo | P. Colangelo, F. De Fazio, F. Jugeau, S. Nicotri | On the light glueball spectrum in a holographic description of QCD | LaTex, 13 pages, 2 figures | Phys.Lett.B652:73-78,2007 | 10.1016/j.physletb.2007.06.072 | BARI-TH/07-562 | hep-ph | null | We investigate the spectra of light scalar and vector glueballs in a
holografic description of QCD with a dilaton background bulk field. In
particular, we study how the glueball masses depend on the conditions on the
dilaton background and on the geometry of the bulk.
| [
{
"created": "Fri, 30 Mar 2007 12:43:19 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Colangelo",
"P.",
""
],
[
"De Fazio",
"F.",
""
],
[
"Jugeau",
"F.",
""
],
[
"Nicotri",
"S.",
""
]
] | We investigate the spectra of light scalar and vector glueballs in a holografic description of QCD with a dilaton background bulk field. In particular, we study how the glueball masses depend on the conditions on the dilaton background and on the geometry of the bulk. |
2304.12481 | Jianhui Zhang | Jian-Hui Zhang | Double Parton Distributions from Euclidean Lattice | 5 pages, 1 figure, typos corrected | null | null | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that double parton distributions, which are important in describing
double parton scattering processes in hadron collisions, can be directly
computed from correlations of equal-time nonlocal Euclidean operators on the
lattice in the large hadron momentum limit. We demonstrate this by taking the
unpolarized color singlet quark double parton distribution as an example, and
present a factorization formula connecting the corresponding lightcone and
Euclidean correlations. This opens a new possibility of studying multiparton
interactions on the Euclidean lattice.
| [
{
"created": "Mon, 24 Apr 2023 22:35:00 GMT",
"version": "v1"
},
{
"created": "Thu, 11 May 2023 05:26:47 GMT",
"version": "v2"
}
] | 2023-05-12 | [
[
"Zhang",
"Jian-Hui",
""
]
] | We show that double parton distributions, which are important in describing double parton scattering processes in hadron collisions, can be directly computed from correlations of equal-time nonlocal Euclidean operators on the lattice in the large hadron momentum limit. We demonstrate this by taking the unpolarized color singlet quark double parton distribution as an example, and present a factorization formula connecting the corresponding lightcone and Euclidean correlations. This opens a new possibility of studying multiparton interactions on the Euclidean lattice. |
hep-ph/9207265 | John Collins | John C. Collins | Hard Scattering in QCD with Polarized Beams | 37 pages + 4 figures (postscript available), plain TeX, PSU/TH/100 | Nucl.Phys. B394 (1993) 169-199 | 10.1016/0550-3213(93)90105-X | null | hep-ph | null | I show that factorization for hard processes in QCD is also valid when the
detected particles are polarized, and that the proof of the theorem determines
the operator form for the parton densities. Particular attention is given to
the case of transversely polarized incoming hadrons.
| [
{
"created": "Mon, 27 Jul 1992 18:12:22 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Collins",
"John C.",
""
]
] | I show that factorization for hard processes in QCD is also valid when the detected particles are polarized, and that the proof of the theorem determines the operator form for the parton densities. Particular attention is given to the case of transversely polarized incoming hadrons. |
hep-ph/0001011 | Li De-Ming | De-Min Li, Hong Yu and Qi-Xing Shen | Is $f_1(1420)$ the partner of $f_1(1285)$ in the $^3P_1$ $q\bar{q}$
nonet? | Latex, 6 pages, to be published in Chin. Phys. lett | Chin.Phys.Lett. 17 (2000) 558-559 | 10.1103/PhysRevE.67.036402 | null | hep-ph | null | Based on a $2\times 2$ mass matrix, the mixing angle of the axial vector
states $f_1(1420)$ and $f_1(1285)$ is determined to be $51.5^{\circ}$, and the
theoretical results about the decay and production of the two states are
presented. The theoretical results are in good agreement with the present
experimental results, which suggests that $f_1(1420)$ can be assigned as the
partner of $f_1(1285)$ in the $^3P_1$ $q\bar{q}$ nonet. We also suggest that
the existence of $f_1(1510)$ needs further experimental confirmation.
| [
{
"created": "Mon, 3 Jan 2000 14:20:43 GMT",
"version": "v1"
}
] | 2013-05-29 | [
[
"Li",
"De-Min",
""
],
[
"Yu",
"Hong",
""
],
[
"Shen",
"Qi-Xing",
""
]
] | Based on a $2\times 2$ mass matrix, the mixing angle of the axial vector states $f_1(1420)$ and $f_1(1285)$ is determined to be $51.5^{\circ}$, and the theoretical results about the decay and production of the two states are presented. The theoretical results are in good agreement with the present experimental results, which suggests that $f_1(1420)$ can be assigned as the partner of $f_1(1285)$ in the $^3P_1$ $q\bar{q}$ nonet. We also suggest that the existence of $f_1(1510)$ needs further experimental confirmation. |
2105.04255 | Bastian Diaz | Basti\'an D\'iaz S\'aez, Patricio Escalona, Sebasti\'an Norero and
Alfonso R. Zerwekh | Fermion Singlet Dark Matter in a Pseudoscalar Dark Matter Portal | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We explore a simple extension to the Standard Model containing two gauge
singlets: a Dirac fermion and a real pseudoscalar. In some regions of the
parameter space both singlets are stable without the necessity of additional
symmetries, then becoming a possible two-component dark matter model. We study
the relic abundance production via freeze-out, with the latter determined by
annihilations, conversions and semi-annihilations. Experimental constraints
from invisible Higgs decay, dark matter relic abundance and direct/indirect
detection are studied. We found three viable regions of the parameter space,
and the model is sensitive to indirect searches.
| [
{
"created": "Mon, 10 May 2021 10:44:45 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Oct 2021 12:23:25 GMT",
"version": "v2"
}
] | 2021-10-07 | [
[
"Sáez",
"Bastián Díaz",
""
],
[
"Escalona",
"Patricio",
""
],
[
"Norero",
"Sebastián",
""
],
[
"Zerwekh",
"Alfonso R.",
""
]
] | We explore a simple extension to the Standard Model containing two gauge singlets: a Dirac fermion and a real pseudoscalar. In some regions of the parameter space both singlets are stable without the necessity of additional symmetries, then becoming a possible two-component dark matter model. We study the relic abundance production via freeze-out, with the latter determined by annihilations, conversions and semi-annihilations. Experimental constraints from invisible Higgs decay, dark matter relic abundance and direct/indirect detection are studied. We found three viable regions of the parameter space, and the model is sensitive to indirect searches. |
0905.1029 | Rudolf Oldeman | R. G. C. Oldeman, M. Meloni, B. Saitta | Resonant antineutrino induced electron capture with low energy
bound-beta beams | 6 pages, 4 figures, 4 tables | Eur.Phys.J.C65:81-87,2010 | 10.1140/epjc/s10052-009-1209-6 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Antineutrino induced electron capture is a resonant process that can have a
larg e cross-section for beams of monochromatic antineutrinos. We calculate the
cross-section of this process and investigate an experimental setup where
monochromatic antineutrinos are produced from the bound-beta decay of fully
ionized radioactive atoms in a storage ring. If the energy between the source
and the target is well matched, the cross-sections can be significantly larger
than the cross-sections of commonly used non-resonant processes. The rate that
can be achieved at a small distance between the source and two targets of
$10^3$ kg is up to one interaction per $8 .3\cdot10^{18}$ decaying atoms. For a
source-target distance corresponding to the first atmospheric neutrino osc
illation maximum, the largest rate is one interaction per $3.2\cdot10^{21}$
decaying atoms, provided that extremely stringent monochromaticity conditions
($10^{-7}$ or better) are achieved in future ion beams.
| [
{
"created": "Thu, 7 May 2009 13:42:04 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Nov 2009 09:34:38 GMT",
"version": "v2"
}
] | 2010-01-06 | [
[
"Oldeman",
"R. G. C.",
""
],
[
"Meloni",
"M.",
""
],
[
"Saitta",
"B.",
""
]
] | Antineutrino induced electron capture is a resonant process that can have a larg e cross-section for beams of monochromatic antineutrinos. We calculate the cross-section of this process and investigate an experimental setup where monochromatic antineutrinos are produced from the bound-beta decay of fully ionized radioactive atoms in a storage ring. If the energy between the source and the target is well matched, the cross-sections can be significantly larger than the cross-sections of commonly used non-resonant processes. The rate that can be achieved at a small distance between the source and two targets of $10^3$ kg is up to one interaction per $8 .3\cdot10^{18}$ decaying atoms. For a source-target distance corresponding to the first atmospheric neutrino osc illation maximum, the largest rate is one interaction per $3.2\cdot10^{21}$ decaying atoms, provided that extremely stringent monochromaticity conditions ($10^{-7}$ or better) are achieved in future ion beams. |
1008.3636 | Koji Ishiwata | Koji Ishiwata, Shigeki Matsumoto, Takeo Moroi | Decaying Dark Matter in Supersymmetric Model and Cosmic-Ray Observations | 24 pages, 5 figures | JHEP 1012:006,2010 | 10.1007/JHEP12(2010)006 | ICRR-Report 572-2010-5, UT-HET 044, UT-10-14 | hep-ph astro-ph.GA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study cosmic-rays in decaying dark matter scenario, assuming that the dark
matter is the lightest superparticle and it decays through a R-parity violating
operator. We calculate the fluxes of cosmic-rays from the decay of the dark
matter and those from the standard astrophysical phenomena in the same
propagation model using the GALPROP package. We reevaluate the preferred
parameters characterizing standard astrophysical cosmic-ray sources with taking
account of the effects of dark matter decay. We show that, if energetic leptons
are produced by the decay of the dark matter, the fluxes of cosmic-ray positron
and electron can be in good agreements with both PAMELA and Fermi-LAT data in
wide parameter region. It is also discussed that, in the case where sizable
number of hadrons are also produced by the decay of the dark matter, the mass
of the dark matter is constrained to be less than 200-300 GeV in order to avoid
the overproduction of anti-proton. We also show that the cosmic gamma-ray flux
can be consistent with the results of Fermi-LAT observation if the mass of the
dark matter is smaller than nearly 4 TeV.
| [
{
"created": "Sat, 21 Aug 2010 14:44:14 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Dec 2010 21:01:15 GMT",
"version": "v2"
}
] | 2010-12-14 | [
[
"Ishiwata",
"Koji",
""
],
[
"Matsumoto",
"Shigeki",
""
],
[
"Moroi",
"Takeo",
""
]
] | We study cosmic-rays in decaying dark matter scenario, assuming that the dark matter is the lightest superparticle and it decays through a R-parity violating operator. We calculate the fluxes of cosmic-rays from the decay of the dark matter and those from the standard astrophysical phenomena in the same propagation model using the GALPROP package. We reevaluate the preferred parameters characterizing standard astrophysical cosmic-ray sources with taking account of the effects of dark matter decay. We show that, if energetic leptons are produced by the decay of the dark matter, the fluxes of cosmic-ray positron and electron can be in good agreements with both PAMELA and Fermi-LAT data in wide parameter region. It is also discussed that, in the case where sizable number of hadrons are also produced by the decay of the dark matter, the mass of the dark matter is constrained to be less than 200-300 GeV in order to avoid the overproduction of anti-proton. We also show that the cosmic gamma-ray flux can be consistent with the results of Fermi-LAT observation if the mass of the dark matter is smaller than nearly 4 TeV. |
hep-ph/0512089 | Babiker Hassanain mr | Thomas Hambye, Babiker Hassanain, John March-Russell, and Martin
Schvellinger | On the Delta I = 1/2 Rule in Holographic QCD | 4 pages, 1 figure, numerical factor corrected, references added | Phys.Rev. D74 (2006) 026003 | 10.1103/PhysRevD.74.026003 | OUTP 05 12P | hep-ph | null | We study the $\Delta I = 1/2$ rule for kaon decays and the $B_K$ parameter
for $K^0 - {\bar K}^0$ mixing in a dual 5-dimensional holographic QCD model. We
perform, in the chiral limit, computations of the relevant four-point
current-current correlators, which depend upon self-interactions among the 5D
bulk fields. Spontaneous chiral symmetry breaking ($\chi$SB) is realized
through boundary conditions on the bulk fields. Numerical results are analyzed
in comparison with QCD, chiral perturbation theory ($\chi$PT) and data, finding
reasonable agreement with the experimental values of the $g_8$ and $g_{27}$
parameters describing the $\Delta I =1/2,3/2$ decay channels.
| [
{
"created": "Wed, 7 Dec 2005 18:51:09 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Apr 2006 09:46:57 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Hambye",
"Thomas",
""
],
[
"Hassanain",
"Babiker",
""
],
[
"March-Russell",
"John",
""
],
[
"Schvellinger",
"Martin",
""
]
] | We study the $\Delta I = 1/2$ rule for kaon decays and the $B_K$ parameter for $K^0 - {\bar K}^0$ mixing in a dual 5-dimensional holographic QCD model. We perform, in the chiral limit, computations of the relevant four-point current-current correlators, which depend upon self-interactions among the 5D bulk fields. Spontaneous chiral symmetry breaking ($\chi$SB) is realized through boundary conditions on the bulk fields. Numerical results are analyzed in comparison with QCD, chiral perturbation theory ($\chi$PT) and data, finding reasonable agreement with the experimental values of the $g_8$ and $g_{27}$ parameters describing the $\Delta I =1/2,3/2$ decay channels. |
hep-ph/9702442 | Tarakeshwar Dasgupta | Tarakeshwar Dasgupta and Pran Nath | R_b in Supergravity Grand Unification with Non-universal Soft SUSY
Breaking | null | Phys.Rev.D56:4194-4197,1997 | 10.1103/PhysRevD.56.4194 | null | hep-ph | null | An analysis of supersymmetric contributions to R_b in supergravity grand
unification with non-universal boundary conditions on soft SUSY breaking in the
scalar sector is given. Effects on R_b of Planck scale corrections on gaugino
masses are also analysed. It is found that there exist regions of the parameter
space where positive corrections to R_b of size $\sim 1 \sigma$ can be gotten.
The region of the parameter space where enhancement of R_b occurs is
identified. Prediction of the full sparticle spectrum for the maximal R_b case
is given. The analysis has implications for the discovery of supersymmetric
particles at colliders.
| [
{
"created": "Thu, 27 Feb 1997 23:02:15 GMT",
"version": "v1"
}
] | 2011-06-02 | [
[
"Dasgupta",
"Tarakeshwar",
""
],
[
"Nath",
"Pran",
""
]
] | An analysis of supersymmetric contributions to R_b in supergravity grand unification with non-universal boundary conditions on soft SUSY breaking in the scalar sector is given. Effects on R_b of Planck scale corrections on gaugino masses are also analysed. It is found that there exist regions of the parameter space where positive corrections to R_b of size $\sim 1 \sigma$ can be gotten. The region of the parameter space where enhancement of R_b occurs is identified. Prediction of the full sparticle spectrum for the maximal R_b case is given. The analysis has implications for the discovery of supersymmetric particles at colliders. |
1602.01994 | Yutaka Sakamura | Yoshio Matsumoto and Yutaka Sakamura | Yukawa couplings in 6D gauge-Higgs unification on $T^2/Z_N$ with
magnetic fluxes | 36 pages, typos corrected | null | 10.1093/ptep/ptw058 | KEK-TH-1888 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the Yukawa couplings in 6D gauge-Higgs unification models on
$T^2/Z_N$ in the presence of magnetic fluxes. We provide general formulae for
them, and numerically evaluate their magnitude in a specific model on
$T^2/Z_3$. Thanks to the nontrivial profiles of the zero-mode wave functions,
the top quark Yukawa coupling can be reproduced without introducing a large
representation of the gauge group for matter fields. However, it is difficult
to realize small Yukawa couplings only by the magnetic fluxes and the
Wilson-line phases because of the complicated structure of the mode functions
on $T^2/Z_N$ ($N=3,4,6$).
| [
{
"created": "Fri, 5 Feb 2016 11:49:41 GMT",
"version": "v1"
},
{
"created": "Fri, 6 May 2016 08:08:22 GMT",
"version": "v2"
}
] | 2016-06-21 | [
[
"Matsumoto",
"Yoshio",
""
],
[
"Sakamura",
"Yutaka",
""
]
] | We discuss the Yukawa couplings in 6D gauge-Higgs unification models on $T^2/Z_N$ in the presence of magnetic fluxes. We provide general formulae for them, and numerically evaluate their magnitude in a specific model on $T^2/Z_3$. Thanks to the nontrivial profiles of the zero-mode wave functions, the top quark Yukawa coupling can be reproduced without introducing a large representation of the gauge group for matter fields. However, it is difficult to realize small Yukawa couplings only by the magnetic fluxes and the Wilson-line phases because of the complicated structure of the mode functions on $T^2/Z_N$ ($N=3,4,6$). |
2406.18469 | Polina Moskvitina | Sascha Caron, Jos\'e Enrique Garc\'ia Navarro, Mar\'ia Moreno
Ll\'acer, Polina Moskvitina, Mats Rovers, Adri\'an Rubio J\'imenez, Roberto
Ruiz de Austri, Zhongyi Zhang | Universal Anomaly Detection at the LHC: Transforming Optimal Classifiers
and the DDD Method | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this work, we present a novel approach to transform supervised classifiers
into effective unsupervised anomaly detectors. The method we have developed,
termed Discriminatory Detection of Distortions (DDD), enhances anomaly
detection by training a discriminator model on both original and artificially
modified datasets. We conducted a comprehensive evaluation of our models on the
Dark Machines Anomaly Score Challenge channels and a search for 4-top quark
events, demonstrating the effectiveness of our approach across various final
states and beyond the Standard Model scenarios.
We compare the performance of the DDD method with the Deep Robust One-Class
Classification method (DROCC), which incorporates signals in the training
process, and the Deep Support Vector Data Description (DeepSVDD) method, a well
established and well performing method for anomaly detection. Results show that
the effectiveness of each model varies by signal and channel, with DDD proving
to be a very effective anomaly detector. We recommend the combined use of
DeepSVDD and DDD for purely unsupervised applications, with the addition of
flow models for improved performance when resources allow.
Findings suggest that network architectures that excel in supervised
contexts, such as the particle transformer with standard model interactions,
also perform well as unsupervised anomaly detectors. We also show that with
these methods, it is likely possible to recognize 4-top quark production as an
anomaly without prior knowledge of the process. We argue that the Large Hadron
Collider community can transform supervised classifiers into anomaly detectors
to uncover potential new physical phenomena in each search.
| [
{
"created": "Wed, 26 Jun 2024 16:27:42 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Jul 2024 15:29:29 GMT",
"version": "v2"
}
] | 2024-07-23 | [
[
"Caron",
"Sascha",
""
],
[
"Navarro",
"José Enrique García",
""
],
[
"Llácer",
"María Moreno",
""
],
[
"Moskvitina",
"Polina",
""
],
[
"Rovers",
"Mats",
""
],
[
"Jímenez",
"Adrián Rubio",
""
],
[
"de Austri",
"... | In this work, we present a novel approach to transform supervised classifiers into effective unsupervised anomaly detectors. The method we have developed, termed Discriminatory Detection of Distortions (DDD), enhances anomaly detection by training a discriminator model on both original and artificially modified datasets. We conducted a comprehensive evaluation of our models on the Dark Machines Anomaly Score Challenge channels and a search for 4-top quark events, demonstrating the effectiveness of our approach across various final states and beyond the Standard Model scenarios. We compare the performance of the DDD method with the Deep Robust One-Class Classification method (DROCC), which incorporates signals in the training process, and the Deep Support Vector Data Description (DeepSVDD) method, a well established and well performing method for anomaly detection. Results show that the effectiveness of each model varies by signal and channel, with DDD proving to be a very effective anomaly detector. We recommend the combined use of DeepSVDD and DDD for purely unsupervised applications, with the addition of flow models for improved performance when resources allow. Findings suggest that network architectures that excel in supervised contexts, such as the particle transformer with standard model interactions, also perform well as unsupervised anomaly detectors. We also show that with these methods, it is likely possible to recognize 4-top quark production as an anomaly without prior knowledge of the process. We argue that the Large Hadron Collider community can transform supervised classifiers into anomaly detectors to uncover potential new physical phenomena in each search. |
hep-ph/0204337 | Pavel Pobylitsa | P.V. Pobylitsa | Positivity bounds on generalized parton distributions in impact
parameter representation | 8 pages | Phys.Rev. D66 (2002) 094002 | 10.1103/PhysRevD.66.094002 | null | hep-ph | null | New positivity bounds are derived for generalized (off-forward) parton
distributions using the impact parameter representation. These inequalities are
stable under the evolution to higher normalization points. The full set of
inequalities is infinite. Several particular cases are considered explicitly.
| [
{
"created": "Mon, 29 Apr 2002 17:32:14 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Aug 2002 20:23:54 GMT",
"version": "v2"
},
{
"created": "Tue, 10 Sep 2002 16:08:55 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Pobylitsa",
"P. V.",
""
]
] | New positivity bounds are derived for generalized (off-forward) parton distributions using the impact parameter representation. These inequalities are stable under the evolution to higher normalization points. The full set of inequalities is infinite. Several particular cases are considered explicitly. |
1502.05250 | George Rupp | George Rupp, Eef van Beveren, and Susana Coito | No serious meson spectroscopy without scattering | 6 pages, 5 figures (7 plots), appolb style, Talk given by G. Rupp at
the "EEF70" Workshop on Unquenched Hadron Spectroscopy: Non-Perturbative
Models and Methods of QCD, Coimbra, 1-5 Sept. 2014, Conference no.
C14-09-01.4 | Acta Phys. Pol. B Proc. Suppl. 8 (2015) 139 | 10.5506/APhysPolBSupp.8.139 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The principal purpose of meson spectroscopy is to understand the confining
force, which is generally assumed to be based on low-energy QCD. This is
usually done in the context of quark models that ignore the dynamical effects
of quark-pair creation and decay. Very recent lattice calculations confirm much
earlier model results showing that neglecting such effects, in the so-called
quenched approximation, may give rise to discrepancies of hundreds of MeV, and
so distort the meson spectra resulting from quark confinement only. Models
attempting to mimic unquenching through a redefinition of the constituent quark
mass or screening of the confining potential at larger interquark separations
are clearly incapable of accounting for the highly non-perturbative and
non-linear effects on mesonic bound-state and resonance poles, as demonstrated
with several published examples.
| [
{
"created": "Wed, 18 Feb 2015 14:34:17 GMT",
"version": "v1"
}
] | 2015-03-12 | [
[
"Rupp",
"George",
""
],
[
"van Beveren",
"Eef",
""
],
[
"Coito",
"Susana",
""
]
] | The principal purpose of meson spectroscopy is to understand the confining force, which is generally assumed to be based on low-energy QCD. This is usually done in the context of quark models that ignore the dynamical effects of quark-pair creation and decay. Very recent lattice calculations confirm much earlier model results showing that neglecting such effects, in the so-called quenched approximation, may give rise to discrepancies of hundreds of MeV, and so distort the meson spectra resulting from quark confinement only. Models attempting to mimic unquenching through a redefinition of the constituent quark mass or screening of the confining potential at larger interquark separations are clearly incapable of accounting for the highly non-perturbative and non-linear effects on mesonic bound-state and resonance poles, as demonstrated with several published examples. |
0709.1772 | Kyungil Kim | Kyung-il Kim, Youngman Kim, Su Houng Lee | Isospin Matter in AdS/QCD | 20 pages, 4 figures. This paper is extened version with changed title
to be published in JKPS | Journal of the Korean Physical Society 2009 55:1381-1388 | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study strange and isospin asymmetric matter in a bottom-up AdS/QCD model.
We first consider isospin matter, which has served as a good testing ground for
nonperturbative QCD. We calculate the isospin chemical potential dependence of
hadronic observables such as the masses and the decay constants of the
pseudo-scalar, vector, and axial-vector mesons. We discuss a possibility of the
charged pion condensation in the matter within the bottom-up AdS/QCD model.
Then, we study the properties of the hadronic observables in strange matter. We
calculate the deconfinement temperature in strange and isospin asymmetric
matter. One of the interesting results of our study is that the critical
temperature at a fixed baryon number density increases when the strangeness
chemical potential is introduced. This suggests that if matter undergoes a
first-order transition to strange matter, the critical temperature shows a
sudden jump at the transition point.
| [
{
"created": "Wed, 12 Sep 2007 08:58:11 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Oct 2009 06:05:00 GMT",
"version": "v2"
}
] | 2009-10-27 | [
[
"Kim",
"Kyung-il",
""
],
[
"Kim",
"Youngman",
""
],
[
"Lee",
"Su Houng",
""
]
] | We study strange and isospin asymmetric matter in a bottom-up AdS/QCD model. We first consider isospin matter, which has served as a good testing ground for nonperturbative QCD. We calculate the isospin chemical potential dependence of hadronic observables such as the masses and the decay constants of the pseudo-scalar, vector, and axial-vector mesons. We discuss a possibility of the charged pion condensation in the matter within the bottom-up AdS/QCD model. Then, we study the properties of the hadronic observables in strange matter. We calculate the deconfinement temperature in strange and isospin asymmetric matter. One of the interesting results of our study is that the critical temperature at a fixed baryon number density increases when the strangeness chemical potential is introduced. This suggests that if matter undergoes a first-order transition to strange matter, the critical temperature shows a sudden jump at the transition point. |
2101.04956 | Guo-Yuan Huang | Guo-yuan Huang, Farinaldo S. Queiroz and Werner Rodejohann | Gauged $L^{}_{\mu}{-}L^{}_{\tau}$ at a muon collider | 9 pages, 6 figures | Phys. Rev. D 103, 095005 (2021) | 10.1103/PhysRevD.103.095005 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We investigate the sensitivity of the projected TeV muon collider to the
gauged $L^{}_{\mu}$-$L^{}_{\tau}$ model. Two processes are considered:
$Z'$-mediated two-body scatterings $\mu^+ \mu^- \to \ell^+ \ell^-$ with $\ell =
\mu$ or $\tau$, and scattering with initial state photon emission, $\mu^+ \mu^-
\to \gamma Z',~Z' \to \ell \overline{\ell}$, where $\ell$ can be $\mu$, $\tau$
or $\nu_{\mu/\tau}$. We quantitatively study the sensitivities of these two
processes by taking into account possible signals and relevant backgrounds in a
muon collider experiment with a center-of-mass energy $\sqrt{s} = 3~{\rm TeV}$
and a luminosity $L=1~{\rm ab^{-1}}$. For two-body scattering one can exclude
$Z'$ masses $M^{}_{Z'} \lesssim 100~{\rm TeV}$ with $\mathcal{O}(1)$ gauge
couplings. When $M^{}_{Z'} \lesssim 1~{\rm TeV} <\sqrt{s}$, one can exclude $g'
\gtrsim 2\times 10^{-2}$. The process with photon emission is more powerful
than the two-body scattering if $M^{}_{Z'} < \sqrt{s}$. For instance, a
sensitivity of $g' \simeq 4 \times 10^{-3}$ can be achieved at $M^{}_{Z'} =
1~{\rm TeV}$. The parameter spaces favored by the $(g-2)^{}_{\mu}$ and $B$
anomalies with $M^{}_{Z'} > 100~{\rm GeV}$ are entirely covered by a muon
collider.
| [
{
"created": "Wed, 13 Jan 2021 09:40:30 GMT",
"version": "v1"
}
] | 2021-05-12 | [
[
"Huang",
"Guo-yuan",
""
],
[
"Queiroz",
"Farinaldo S.",
""
],
[
"Rodejohann",
"Werner",
""
]
] | We investigate the sensitivity of the projected TeV muon collider to the gauged $L^{}_{\mu}$-$L^{}_{\tau}$ model. Two processes are considered: $Z'$-mediated two-body scatterings $\mu^+ \mu^- \to \ell^+ \ell^-$ with $\ell = \mu$ or $\tau$, and scattering with initial state photon emission, $\mu^+ \mu^- \to \gamma Z',~Z' \to \ell \overline{\ell}$, where $\ell$ can be $\mu$, $\tau$ or $\nu_{\mu/\tau}$. We quantitatively study the sensitivities of these two processes by taking into account possible signals and relevant backgrounds in a muon collider experiment with a center-of-mass energy $\sqrt{s} = 3~{\rm TeV}$ and a luminosity $L=1~{\rm ab^{-1}}$. For two-body scattering one can exclude $Z'$ masses $M^{}_{Z'} \lesssim 100~{\rm TeV}$ with $\mathcal{O}(1)$ gauge couplings. When $M^{}_{Z'} \lesssim 1~{\rm TeV} <\sqrt{s}$, one can exclude $g' \gtrsim 2\times 10^{-2}$. The process with photon emission is more powerful than the two-body scattering if $M^{}_{Z'} < \sqrt{s}$. For instance, a sensitivity of $g' \simeq 4 \times 10^{-3}$ can be achieved at $M^{}_{Z'} = 1~{\rm TeV}$. The parameter spaces favored by the $(g-2)^{}_{\mu}$ and $B$ anomalies with $M^{}_{Z'} > 100~{\rm GeV}$ are entirely covered by a muon collider. |
hep-ph/0607122 | Joan Rojo | Joan Rojo | The neural network approach to parton distribution functions | Ph. D. Thesis, 163 pages, version with higher resolution figures
available from the following website:
http://www.ecm.ub.es/~joanrojo/thesis.pdf | null | null | null | hep-ph | null | We introduce the neural network approach to the parametrization of parton
distributions. After a general introduction, we present in detail our approach
to parametrize experimental data, based on a combination of Monte Carlo methods
and neural networks. We apply this strategy first in three different cases: the
proton structure function, hadronic tau decays and B meson decay spectra.
Finally we describe the neural network approach applied to the parametrization
of parton distribution functions, and present results on the nonsinglet parton
distribution.
| [
{
"created": "Tue, 11 Jul 2006 17:16:35 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Rojo",
"Joan",
""
]
] | We introduce the neural network approach to the parametrization of parton distributions. After a general introduction, we present in detail our approach to parametrize experimental data, based on a combination of Monte Carlo methods and neural networks. We apply this strategy first in three different cases: the proton structure function, hadronic tau decays and B meson decay spectra. Finally we describe the neural network approach applied to the parametrization of parton distribution functions, and present results on the nonsinglet parton distribution. |
1312.3348 | Dmitri Kharzeev | Dmitri E. Kharzeev | The Chiral Magnetic Effect and Anomaly-Induced Transport | 48 pages, 5 figures; minor improvements, final version to appear in
Progress in Particle and Nuclear Physics | null | 10.1016/j.ppnp.2014.01.002 | null | hep-ph cond-mat.mes-hall hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Chiral Magnetic Effect (CME) is the phenomenon of electric charge
separation along the external magnetic field that is induced by the chirality
imbalance. The CME is a macroscopic quantum effect - it is a manifestation of
the chiral anomaly creating a collective motion in Dirac sea. Because the
chirality imbalance is related to the global topology of gauge fields, the CME
current is topologically protected and hence non-dissipative even in the
presence of strong interactions. As a result, the CME and related quantum
phenomena affect the hydrodynamical and transport behavior of systems
possessing chiral fermions, from the quark-gluon plasma to chiral materials.
The goal of the present review is to provide an elementary introduction into
the main ideas underlying the physics of CME, a historical perspective, and a
guide to the rapidly growing literature on this topic.
| [
{
"created": "Wed, 11 Dec 2013 21:18:18 GMT",
"version": "v1"
},
{
"created": "Sun, 22 Dec 2013 20:57:49 GMT",
"version": "v2"
}
] | 2014-03-05 | [
[
"Kharzeev",
"Dmitri E.",
""
]
] | The Chiral Magnetic Effect (CME) is the phenomenon of electric charge separation along the external magnetic field that is induced by the chirality imbalance. The CME is a macroscopic quantum effect - it is a manifestation of the chiral anomaly creating a collective motion in Dirac sea. Because the chirality imbalance is related to the global topology of gauge fields, the CME current is topologically protected and hence non-dissipative even in the presence of strong interactions. As a result, the CME and related quantum phenomena affect the hydrodynamical and transport behavior of systems possessing chiral fermions, from the quark-gluon plasma to chiral materials. The goal of the present review is to provide an elementary introduction into the main ideas underlying the physics of CME, a historical perspective, and a guide to the rapidly growing literature on this topic. |
hep-ph/0207360 | Jihn E. Kim | Jihn E. Kim | A review of self-tuning solutions of cosmological constant | LaTeX file of 15 pages, including figures. "5th Int. UCLA Symposium
on Sources and Detection of Dark Matter and Dark Energy in the Universe",
Marina del Rey, CA, 20-22 Feb. 2002. SNUTP-02/023 | null | null | null | hep-ph | null | The self-tuning solutions of the cosmological constant is reviewed, with the
emphasis on the recent attempts in extra dimensional gravity with a brane
boundary.
| [
{
"created": "Wed, 31 Jul 2002 02:15:14 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kim",
"Jihn E.",
""
]
] | The self-tuning solutions of the cosmological constant is reviewed, with the emphasis on the recent attempts in extra dimensional gravity with a brane boundary. |
hep-ph/9309335 | Nathan Seiberg | N. Seiberg | Naturalness Versus Supersymmetric Non-renormalization Theorems | 14 pages, RU-93-45 | Phys.Lett.B318:469-475,1993 | 10.1016/0370-2693(93)91541-T | null | hep-ph hep-th | null | We give an intuitive proof of a new non-renormalization theorem in
supersymmetric field theories. It applies both perturbatively and
non-perturbatively. The superpotential is not renormalized in perturbation
theory but receives non-perturbative corrections. However, these
non-perturbative corrections are {\it not} generic functions of the fields
consistent with the symmetries. Certain invariant terms are not generated. This
violation of naturalness has applications to dynamical supersymmetry breaking.
| [
{
"created": "Thu, 30 Sep 1993 19:39:30 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Seiberg",
"N.",
""
]
] | We give an intuitive proof of a new non-renormalization theorem in supersymmetric field theories. It applies both perturbatively and non-perturbatively. The superpotential is not renormalized in perturbation theory but receives non-perturbative corrections. However, these non-perturbative corrections are {\it not} generic functions of the fields consistent with the symmetries. Certain invariant terms are not generated. This violation of naturalness has applications to dynamical supersymmetry breaking. |
1105.4899 | Wayne de Paula | O. Oliveira, W. de Paula and T. Frederico | Linking Dynamical Gluon Mass to Chiral Symmetry Breaking via a QCD Low
Energy Effective Field Theory | null | null | null | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A low energy effective field theory model for QCD with a scalar color octet
field is discussed. The model relates the gluon mass, the constituent quark
masses and the quark condensate. The gluon mass comes about $\sqrt{N_c}\,
\Lambda_{QCD}$ with the quark condensate being proportional to the gluon mass
squared. The model suggests that the restoration of chiral symmetry and the
deconfinement transition occur at the same temperature and that, near the
transition, the critical exponent for the condensate is twice the gluon mass
one. The model also favors the decoupling like solution for the gluon
propagator.
| [
{
"created": "Tue, 24 May 2011 21:17:17 GMT",
"version": "v1"
}
] | 2011-05-27 | [
[
"Oliveira",
"O.",
""
],
[
"de Paula",
"W.",
""
],
[
"Frederico",
"T.",
""
]
] | A low energy effective field theory model for QCD with a scalar color octet field is discussed. The model relates the gluon mass, the constituent quark masses and the quark condensate. The gluon mass comes about $\sqrt{N_c}\, \Lambda_{QCD}$ with the quark condensate being proportional to the gluon mass squared. The model suggests that the restoration of chiral symmetry and the deconfinement transition occur at the same temperature and that, near the transition, the critical exponent for the condensate is twice the gluon mass one. The model also favors the decoupling like solution for the gluon propagator. |
1606.07764 | Antonio Pich | Antonio Pich and Antonio Rodr\'iguez S\'anchez | Updated determination of $\alpha_s(m_\tau^2)$ from tau decays | Invited contribution to the MITP workshop on Determination of the
Fundamental Parameters in QCD (Mainz, 7-11 March 2016). 15 pages, 8 figures | null | 10.1142/S0217732316300329 | IFIC/16-36, FTUV/16-0624 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the most recent release of the ALEPH $\tau$ decay data, we present a
very detailed phenomenological update of the $\alpha_s(m_\tau^2)$
determination. We have exploited the sensitivity to the strong coupling in many
different ways, exploring several complementary methodologies. All
determinations turn out to be in excellent agreement, allowing us to extract a
very reliable value of the strong coupling. We find
$\alpha_{s}^{(n_f=3)}(m_\tau^2) = 0.328 \pm 0.012$ which implies
$\alpha_{s}^{(n_f=5)}(M_Z^{2}) = 0.1197\pm 0.0014$. We critically revise
previous work, and point out the problems flawing some recent analyses which
claim slightly smaller values.
| [
{
"created": "Fri, 24 Jun 2016 17:01:29 GMT",
"version": "v1"
}
] | 2016-10-12 | [
[
"Pich",
"Antonio",
""
],
[
"Sánchez",
"Antonio Rodríguez",
""
]
] | Using the most recent release of the ALEPH $\tau$ decay data, we present a very detailed phenomenological update of the $\alpha_s(m_\tau^2)$ determination. We have exploited the sensitivity to the strong coupling in many different ways, exploring several complementary methodologies. All determinations turn out to be in excellent agreement, allowing us to extract a very reliable value of the strong coupling. We find $\alpha_{s}^{(n_f=3)}(m_\tau^2) = 0.328 \pm 0.012$ which implies $\alpha_{s}^{(n_f=5)}(M_Z^{2}) = 0.1197\pm 0.0014$. We critically revise previous work, and point out the problems flawing some recent analyses which claim slightly smaller values. |
2112.01395 | Fei Gao | Fei Gao, Jan M. Pawlowski | Phase structure of 2+1-flavour QCD and the magnetic equation of state | 20 pages, 13 figures | null | 10.1103/PhysRevD.105.094020 | null | hep-ph hep-lat hep-th nucl-th | http://creativecommons.org/licenses/by/4.0/ | We determine the chiral phase structure of $2+1$-flavour QCD in dependence of
temperature and the light flavour quark mass with Dyson-Schwinger equations.
Specifically, we compute the renormalised chiral condensate and its
susceptibility. The latter is used to determine the (pseudo)critical
temperature for general light current quark masses. In the chiral limit we
obtain a critical temperature of about 141\,MeV. This result is in quantitative
agreement with recent functional renormalisation group results in QCD, and is
compatible with the respective lattice results. We also compute the order
parameter potential of the light chiral condensate and map out the regime in
the phase diagram which exhibits quasi-massless modes, and discuss the
respective chiral dynamics.
| [
{
"created": "Wed, 1 Dec 2021 07:02:32 GMT",
"version": "v1"
}
] | 2022-06-01 | [
[
"Gao",
"Fei",
""
],
[
"Pawlowski",
"Jan M.",
""
]
] | We determine the chiral phase structure of $2+1$-flavour QCD in dependence of temperature and the light flavour quark mass with Dyson-Schwinger equations. Specifically, we compute the renormalised chiral condensate and its susceptibility. The latter is used to determine the (pseudo)critical temperature for general light current quark masses. In the chiral limit we obtain a critical temperature of about 141\,MeV. This result is in quantitative agreement with recent functional renormalisation group results in QCD, and is compatible with the respective lattice results. We also compute the order parameter potential of the light chiral condensate and map out the regime in the phase diagram which exhibits quasi-massless modes, and discuss the respective chiral dynamics. |
2207.04085 | Iv\'an Pacheco | Iv\'an Pacheco and Pablo Roig | Lepton Flavour Violation in Hadron Decays of the Tau Lepton within the
Littlest Higgs Model with T-parity | 36 pages, 15 figures, 5 tables. Improved presentation and more
concise phenomenological analysis. Version accepted for publication in JHEP | JHEP09(2022)144 | 10.1007/JHEP09(2022)144 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We first study the hadronic lepton flavor violating tau decays within the
littlest Higgs model with T-parity (including one or two pseudoscalars, or a
vector resonance). We consider the case where only T-odd particles and partner
fermions contribute, and also its extension including Majorana neutrinos coming
from an inverse seesaw. In both cases our mean values lie only one order of
magnitude below current upper limits, strengthening the case of searching for
these decays in the quest for new physics.
| [
{
"created": "Fri, 8 Jul 2022 18:19:47 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Sep 2022 19:13:32 GMT",
"version": "v2"
}
] | 2022-09-22 | [
[
"Pacheco",
"Iván",
""
],
[
"Roig",
"Pablo",
""
]
] | We first study the hadronic lepton flavor violating tau decays within the littlest Higgs model with T-parity (including one or two pseudoscalars, or a vector resonance). We consider the case where only T-odd particles and partner fermions contribute, and also its extension including Majorana neutrinos coming from an inverse seesaw. In both cases our mean values lie only one order of magnitude below current upper limits, strengthening the case of searching for these decays in the quest for new physics. |
1706.08994 | Gretel Quintero Angulo | G. Quintero Angulo, A. P\'erez Mart\'inez and H. P\'erez Rojas | Thermodynamical properties of a neutral vector boson gas in a constant
magnetic field | 17 pages, 6 figures | Phys. Rev. C 96, 045810 (2017) | 10.1103/PhysRevC.96.045810 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The thermodynamical properties of a neutral vector boson gas in a constant
magnetic field are studied starting from the spectrum given by Proca formalism.
Bose Einstein Condensation (BEC) and magnetization are obtained, for the three
and one dimensional cases, in the limit of low temperatures. In three
dimensions the gas undergoes a phase transition to an usual BEC in which the
critical temperature depends on the magnetic field. In one dimension a diffuse
condensate appears as for the charged vector boson gas. In both cases, the
condensation is reached not only by decreasing the temperature but also by
increasing the magnetic field. In three and one dimensions self-magnetization
is possible. The anisotropy in the pressures due to axial symmetry imposed to
the system by the magnetic field is also discussed. The astrophysical
implications are commented.
| [
{
"created": "Tue, 27 Jun 2017 18:18:18 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jun 2017 19:49:32 GMT",
"version": "v2"
}
] | 2017-10-25 | [
[
"Angulo",
"G. Quintero",
""
],
[
"Martínez",
"A. Pérez",
""
],
[
"Rojas",
"H. Pérez",
""
]
] | The thermodynamical properties of a neutral vector boson gas in a constant magnetic field are studied starting from the spectrum given by Proca formalism. Bose Einstein Condensation (BEC) and magnetization are obtained, for the three and one dimensional cases, in the limit of low temperatures. In three dimensions the gas undergoes a phase transition to an usual BEC in which the critical temperature depends on the magnetic field. In one dimension a diffuse condensate appears as for the charged vector boson gas. In both cases, the condensation is reached not only by decreasing the temperature but also by increasing the magnetic field. In three and one dimensions self-magnetization is possible. The anisotropy in the pressures due to axial symmetry imposed to the system by the magnetic field is also discussed. The astrophysical implications are commented. |
hep-ph/9702311 | Nico Schoonderwoerd | N. C. J. Schoonderwoerd and B. L. G. Bakker (Department of Physics and
Astronomy, Vrije Universiteit, Amsterdam, The Netherlands) | Equivalence of renormalized covariant and light-front perturbation
theory: I. Longitudinal divergences in the Yukawa model | 11 pages, epsf, revtex, contains more elaborate explanation of Forced
Instantaneous Loops (FILs) | null | 10.1103/PhysRevD.57.4965 | VUTH 97-4 | hep-ph hep-th | null | Light-front perturbation theory has been proposed as an alternative to
covariant perturbation theory. Light-front perturbation theory is only
acceptable if it produces invariant S-matrix elements. Doubts have been raised
concerning the equivalence of light-front and covariant perturbation theory.
One of the obstacles to a rigorous proof of equivalence is the occurrence of
longitudinal divergences not present in covariant perturbation theory. We show
in the case of the Yukawa model of fermions interacting with scalar bosons at
the one-loop level how to deal with the longitudinal divergences. Invariant
S-matrix elements are obtained using our method.
| [
{
"created": "Wed, 12 Feb 1997 13:56:52 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Jun 1997 09:45:30 GMT",
"version": "v2"
},
{
"created": "Wed, 28 Jan 1998 18:22:17 GMT",
"version": "v3"
},
{
"created": "Thu, 29 Jan 1998 09:54:51 GMT",
"version": "v4"
}
] | 2009-10-30 | [
[
"Schoonderwoerd",
"N. C. J.",
"",
"Department of Physics and\n Astronomy, Vrije Universiteit, Amsterdam, The Netherlands"
],
[
"Bakker",
"B. L. G.",
"",
"Department of Physics and\n Astronomy, Vrije Universiteit, Amsterdam, The Netherlands"
]
] | Light-front perturbation theory has been proposed as an alternative to covariant perturbation theory. Light-front perturbation theory is only acceptable if it produces invariant S-matrix elements. Doubts have been raised concerning the equivalence of light-front and covariant perturbation theory. One of the obstacles to a rigorous proof of equivalence is the occurrence of longitudinal divergences not present in covariant perturbation theory. We show in the case of the Yukawa model of fermions interacting with scalar bosons at the one-loop level how to deal with the longitudinal divergences. Invariant S-matrix elements are obtained using our method. |
hep-ph/9809244 | Stefano Moretti | S. Moretti (RAL, UK) and K. Odagiri (Cambridge, UK) | The phenomenology of $W^\pm H^\mp$ production at the Large Hadron
Collider | 17 pages, latex, epsfig, 8 figures (paper also available at
http://www.hep.phy.cam.ac.uk/theory/papers/ ) | Phys.Rev.D59:055008,1999 | 10.1103/PhysRevD.59.055008 | RAL-TR-1998-063, Cavendish-HEP-98/13 | hep-ph | null | Barrientos Bendezu' and Kniehl [hep-ph/9807480] recently suggested that
$W^\pm H^\mp$ associated production may be a useful channel in the search for
the elusive heavy charged Higgs bosons of the 2 Higgs Doublet Model at the
Large Hadron Collider. We investigate the phenomenology of this mechanism in
the Minimal Supersymmetric Standard Model, with special attention paid to the
most likely heavy Higgs decay, $H^\mp\to tb\to b\bar b W^\mp$, and to the
irreducible background from top pair production. We find that the semi-leptonic
signature `$b\bar b W^+W^-\to b\bar b jj \ell$ + missing momentum' is dominated
by top-antitop events, which overwhelm the charged Higgs signal over the heavy
mass range that can be probed at the CERN collider
| [
{
"created": "Thu, 3 Sep 1998 10:16:20 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Moretti",
"S.",
"",
"RAL, UK"
],
[
"Odagiri",
"K.",
"",
"Cambridge, UK"
]
] | Barrientos Bendezu' and Kniehl [hep-ph/9807480] recently suggested that $W^\pm H^\mp$ associated production may be a useful channel in the search for the elusive heavy charged Higgs bosons of the 2 Higgs Doublet Model at the Large Hadron Collider. We investigate the phenomenology of this mechanism in the Minimal Supersymmetric Standard Model, with special attention paid to the most likely heavy Higgs decay, $H^\mp\to tb\to b\bar b W^\mp$, and to the irreducible background from top pair production. We find that the semi-leptonic signature `$b\bar b W^+W^-\to b\bar b jj \ell$ + missing momentum' is dominated by top-antitop events, which overwhelm the charged Higgs signal over the heavy mass range that can be probed at the CERN collider |
0906.1229 | Thomas A. Trainor | Thomas A. Trainor | Is hydrodynamics relevant to RHIC collisions? | 19 pages, 17 figures | J.Phys.G37:085004,2010 | 10.1088/0954-3899/37/8/085004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The hydrodynamic (hydro) model applied to heavy ion data from the
relativistic heavy ion collider (RHIC) in the form of single-particle spectra
and correlations seems to indicate that a dense QCD medium nearly opaque to
partons, a strongly-coupled quark-gluon plasma (sQGP), is formed in
more-central Au-Au collisions, and that the sQGP may have a very small
viscosity ("perfect liquid"). Measurements of radial and elliptic flows, with
possible coalescence of "constituent quarks" to form hadrons, seem to support
the conclusion. However, other measurements provide contradictory evidence.
Unbiased angular correlations indicate that a large number of back-to-back jets
from initial-state scattered partons with energies as low as 3 GeV survive as
"minijet" hadron correlations even in central Au-Au collisions, suggesting near
transparency. Two-component analysis of single-particle hadron spectra reveals
a corresponding spectrum hard component (parton fragment distribution described
by pQCD) which can masquerade as "radial flow" in some spectrum analysis.
Reinterpretation of "elliptic flow" as a QCD scattering process resulting in
fragmentation is also possible. In this paper I review analysis methods and
results in the context of two paradigms: the conventional
hydrodynamics/hard-probes paradigm and an alternative quadrupole/minijets
paradigm. Based on re-interpretation of fiducial data I argue that
hydrodynamics may not be relevant to RHIC collisions. Collision evolution may
be dominated by parton scattering and fragmentation, albeit the fragmentation
process is strongly modified in more-central A-A collisions.
| [
{
"created": "Sat, 6 Jun 2009 05:56:02 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Trainor",
"Thomas A.",
""
]
] | The hydrodynamic (hydro) model applied to heavy ion data from the relativistic heavy ion collider (RHIC) in the form of single-particle spectra and correlations seems to indicate that a dense QCD medium nearly opaque to partons, a strongly-coupled quark-gluon plasma (sQGP), is formed in more-central Au-Au collisions, and that the sQGP may have a very small viscosity ("perfect liquid"). Measurements of radial and elliptic flows, with possible coalescence of "constituent quarks" to form hadrons, seem to support the conclusion. However, other measurements provide contradictory evidence. Unbiased angular correlations indicate that a large number of back-to-back jets from initial-state scattered partons with energies as low as 3 GeV survive as "minijet" hadron correlations even in central Au-Au collisions, suggesting near transparency. Two-component analysis of single-particle hadron spectra reveals a corresponding spectrum hard component (parton fragment distribution described by pQCD) which can masquerade as "radial flow" in some spectrum analysis. Reinterpretation of "elliptic flow" as a QCD scattering process resulting in fragmentation is also possible. In this paper I review analysis methods and results in the context of two paradigms: the conventional hydrodynamics/hard-probes paradigm and an alternative quadrupole/minijets paradigm. Based on re-interpretation of fiducial data I argue that hydrodynamics may not be relevant to RHIC collisions. Collision evolution may be dominated by parton scattering and fragmentation, albeit the fragmentation process is strongly modified in more-central A-A collisions. |
2103.14022 | Jos\'e Eliel Camargo Molina | Jos\'e Eliel Camargo-Molina, Rikard Enberg, Johan L\"ofgren | A new perspective on the electroweak phase transition in the Standard
Model Effective Field Theory | 18 pages, 5 figures (version accepted for publication, minor changes) | J. High Energ. Phys. 2021, 127 (2021) | 10.1007/JHEP10(2021)127 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A first-order Electroweak Phase Transition (EWPT) could explain the observed
baryon-antibaryon asymmetry and its dynamics could yield a detectable
gravitational wave signature, while the underlying physics would be within the
reach of colliders. The Standard Model, however, predicts a crossover
transition. We therefore study the EWPT in the Standard Model Effective Field
Theory (SMEFT) including dimension-six operators. A first-order EWPT has
previously been shown to be possible in the SMEFT. Phenomenology studies have
focused on scenarios with a tree-level barrier between minima, which requires a
negative Higgs quartic coupling and a new physics scale low enough to raise
questions about the validity of the EFT approach. In this work we stress that a
first-order EWPT is also possible when the barrier between minima is generated
radiatively, the quartic coupling is positive, the scale of new physics is
higher, and there is good agreement with experimental bounds. Our calculation
is done in a consistent, gauge-invariant way, and we carefully analyze the
scaling of parameters necessary to generate a barrier in the potential. We
perform a global fit in the relevant parameter space and explicitly find the
points with a first-order transition that agree with experimental data. We also
briefly discuss the prospects for probing the allowed parameter space using
di-Higgs production in colliders.
| [
{
"created": "Thu, 25 Mar 2021 17:58:40 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Apr 2021 07:49:55 GMT",
"version": "v2"
},
{
"created": "Thu, 14 Oct 2021 11:54:12 GMT",
"version": "v3"
}
] | 2021-10-20 | [
[
"Camargo-Molina",
"José Eliel",
""
],
[
"Enberg",
"Rikard",
""
],
[
"Löfgren",
"Johan",
""
]
] | A first-order Electroweak Phase Transition (EWPT) could explain the observed baryon-antibaryon asymmetry and its dynamics could yield a detectable gravitational wave signature, while the underlying physics would be within the reach of colliders. The Standard Model, however, predicts a crossover transition. We therefore study the EWPT in the Standard Model Effective Field Theory (SMEFT) including dimension-six operators. A first-order EWPT has previously been shown to be possible in the SMEFT. Phenomenology studies have focused on scenarios with a tree-level barrier between minima, which requires a negative Higgs quartic coupling and a new physics scale low enough to raise questions about the validity of the EFT approach. In this work we stress that a first-order EWPT is also possible when the barrier between minima is generated radiatively, the quartic coupling is positive, the scale of new physics is higher, and there is good agreement with experimental bounds. Our calculation is done in a consistent, gauge-invariant way, and we carefully analyze the scaling of parameters necessary to generate a barrier in the potential. We perform a global fit in the relevant parameter space and explicitly find the points with a first-order transition that agree with experimental data. We also briefly discuss the prospects for probing the allowed parameter space using di-Higgs production in colliders. |
1804.09278 | Thomas Roxlo | Thomas Roxlo and Matthew Reece | Opening the black box of neural nets: case studies in stop/top
discrimination | null | null | null | null | hep-ph stat.ML | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce techniques for exploring the functionality of a neural network
and extracting simple, human-readable approximations to its performance. By
performing gradient ascent on the input space of the network, we are able to
produce large populations of artificial events which strongly excite a given
classifier. By studying the populations of these events, we then directly
produce what are essentially contour maps of the network's classification
function. Combined with a suite of tools for identifying the input dimensions
deemed most important by the network, we can utilize these maps to efficiently
interpret the dominant criteria by which the network makes its classification.
As a test case, we study networks trained to discriminate supersymmetric stop
production in the dilepton channel from Standard Model backgrounds. In the case
of a heavy stop decaying to a light neutralino, we find individual neurons with
large mutual information with $m_{T2}^{\ell\ell}$, a human-designed variable
for optimizing the analysis. The network selects events with significant
missing $p_T$ oriented azimuthally away from both leptons, efficiently
rejecting $t\overline{t}$ background. In the case of a light stop with
three-body decays to $Wb{\widetilde \chi}$ and little phase space, we find
neurons that smoothly interpolate between a similar top-rejection strategy and
an ISR-tagging strategy allowing for more missing momentum. We also find that a
neural network trained on a stealth stop parameter point learns novel angular
correlations.
| [
{
"created": "Tue, 24 Apr 2018 22:08:54 GMT",
"version": "v1"
}
] | 2018-04-26 | [
[
"Roxlo",
"Thomas",
""
],
[
"Reece",
"Matthew",
""
]
] | We introduce techniques for exploring the functionality of a neural network and extracting simple, human-readable approximations to its performance. By performing gradient ascent on the input space of the network, we are able to produce large populations of artificial events which strongly excite a given classifier. By studying the populations of these events, we then directly produce what are essentially contour maps of the network's classification function. Combined with a suite of tools for identifying the input dimensions deemed most important by the network, we can utilize these maps to efficiently interpret the dominant criteria by which the network makes its classification. As a test case, we study networks trained to discriminate supersymmetric stop production in the dilepton channel from Standard Model backgrounds. In the case of a heavy stop decaying to a light neutralino, we find individual neurons with large mutual information with $m_{T2}^{\ell\ell}$, a human-designed variable for optimizing the analysis. The network selects events with significant missing $p_T$ oriented azimuthally away from both leptons, efficiently rejecting $t\overline{t}$ background. In the case of a light stop with three-body decays to $Wb{\widetilde \chi}$ and little phase space, we find neurons that smoothly interpolate between a similar top-rejection strategy and an ISR-tagging strategy allowing for more missing momentum. We also find that a neural network trained on a stealth stop parameter point learns novel angular correlations. |
2108.13422 | Mariana Carrillo-Gonz\'alez | Mariana Carrillo Gonz\'alez, Natalia Toro | Cosmology and Signals of Light Pseudo-Dirac Dark Matter | 48 pages plus appendices, 26 figures | null | null | Imperial/TP/2021/MC/03 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we analyze the cosmological evolution, allowed parameter
space, and observational prospects for a dark sector consisting of thermally
produced pseudo-Dirac fermions with a small mass splitting, coupled to the
Standard Model through a dark photon. This scenario is particularly notable in
the context of sub-GeV dark matter, where the mass-off-diagonal leading
interaction limits applicability of both CMB energy injection constraints and
standard direct detection searches. We present the first general study of the
thermal history of pseudo-Dirac DM with splittings from 100 eV to MeV, focusing
on the depletion of the heavier "excited" state abundance via scatterings and
decays, and on the distinctive signals arising from its small surviving
abundance. We analyze CMB energy injection bounds on both DM annihilation and
decay, accelerator-based probes, and new line-like direct-detection signals
from the excited DM down-scattering on either nuclei or electrons, as well as
future search prospects in each channel. We also comment on the relevance of
this signal to the few-keV Xenon1T electron excess and on possible diurnal
modulation of this signal, and introduce a signal-strength parametrization to
facilitate the comparison of future experimental results to theoretical
expectations.
| [
{
"created": "Mon, 30 Aug 2021 18:00:00 GMT",
"version": "v1"
}
] | 2021-09-02 | [
[
"González",
"Mariana Carrillo",
""
],
[
"Toro",
"Natalia",
""
]
] | In this paper, we analyze the cosmological evolution, allowed parameter space, and observational prospects for a dark sector consisting of thermally produced pseudo-Dirac fermions with a small mass splitting, coupled to the Standard Model through a dark photon. This scenario is particularly notable in the context of sub-GeV dark matter, where the mass-off-diagonal leading interaction limits applicability of both CMB energy injection constraints and standard direct detection searches. We present the first general study of the thermal history of pseudo-Dirac DM with splittings from 100 eV to MeV, focusing on the depletion of the heavier "excited" state abundance via scatterings and decays, and on the distinctive signals arising from its small surviving abundance. We analyze CMB energy injection bounds on both DM annihilation and decay, accelerator-based probes, and new line-like direct-detection signals from the excited DM down-scattering on either nuclei or electrons, as well as future search prospects in each channel. We also comment on the relevance of this signal to the few-keV Xenon1T electron excess and on possible diurnal modulation of this signal, and introduce a signal-strength parametrization to facilitate the comparison of future experimental results to theoretical expectations. |
1409.6132 | Andr\'e David | Andr\'e David, Jaana Heikkil\"a and Giovanni Petrucciani | Searching for degenerate Higgs bosons - A profile likelihood ratio
method to test for mass-degenerate states in the presence of incomplete data
and uncertainties | null | European Physical Journal C 75 (2015) 49 | 10.1140/epjc/s10052-015-3279-y | null | hep-ph physics.data-an | http://creativecommons.org/licenses/by/3.0/ | Using the likelihood ratio test statistic, we present a method which can be
employed to test the hypothesis of a single Higgs boson using the matrix of
measured signal strengths. This method can be applied in the presence of
incomplete data and takes into account uncertainties on the measurements. The
p-value against the hypothesis of a single Higgs boson is defined from the
expected distribution of the test statistic, generated using
pseudo-experiments. The applicability of the likelihood-based test is
demonstrated using numerical examples with uncertainties and missing matrix
elements.
| [
{
"created": "Mon, 22 Sep 2014 10:06:39 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Feb 2015 11:40:14 GMT",
"version": "v2"
}
] | 2015-02-05 | [
[
"David",
"André",
""
],
[
"Heikkilä",
"Jaana",
""
],
[
"Petrucciani",
"Giovanni",
""
]
] | Using the likelihood ratio test statistic, we present a method which can be employed to test the hypothesis of a single Higgs boson using the matrix of measured signal strengths. This method can be applied in the presence of incomplete data and takes into account uncertainties on the measurements. The p-value against the hypothesis of a single Higgs boson is defined from the expected distribution of the test statistic, generated using pseudo-experiments. The applicability of the likelihood-based test is demonstrated using numerical examples with uncertainties and missing matrix elements. |
hep-ph/9411408 | Ernest Ma | Ernest Ma (UC Riverside) | Left-Right Gauge Symmetry at the TeV Energy Scale | 7 pages (latex), 2nd of 2 talks given at the 7th Adriatic Meeting on
Particle Physics, Brijuni, Croatia (September 1994) | null | null | UCRHEP-T138 (November 1994) | hep-ph | null | Two first examples beyond the standard model are given which exhibit
left-right symmetry (g_L = g_R) and supersymmetry at a few TeV, together with
gauge-coupling unification at around 10^{16} GeV.
| [
{
"created": "Mon, 28 Nov 1994 17:17:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ma",
"Ernest",
"",
"UC Riverside"
]
] | Two first examples beyond the standard model are given which exhibit left-right symmetry (g_L = g_R) and supersymmetry at a few TeV, together with gauge-coupling unification at around 10^{16} GeV. |
hep-ph/0201004 | Jan Kalinowski | Wojciech Krolikowski | Search for fermion universality of the Dirac component of neutrino mass
matrix | 23 pages, latex, no figures, misprints are corrected, and in order to
make the paper more selfcontained some addenda are introduced | Acta Phys.Polon. B33 (2002) 1747-1774 | null | IFT-02/01 | hep-ph | null | An effective texture is presented for six Majorana neutrinos, three active
and three (conventional) sterile, based on a 6x6 mass matrix, whose 3x3
active--sterile component (i.e., Dirac component) is conjectured to get a
fermion universal form similar to the constructed previously 3x3 mass matrix
for charged leptons and 3x3 mass matrices for up and down quarks. This is true,
however, when the bimaximal mixing, specific for neutrinos, is transformed out
unitarily from the neutrino mass matrix. The 3x3 active--active component
(i.e., lefthanded component) of neutrino 6x6 mass matrix is diagonal and gets
degenerate entries. It dominates over the whole neutrino mass matrix. In such a
texture, three neutrino masses are nearly degenerate, $ m_1 \simeq m_2 \simeq
m_3 $, but their mass-squared differences appear hierarchical, $\Delta m^2_{21}
\ll \Delta m^2_{32} \simeq \Delta m^2_{31}$, while the remaining three neutrino
masses can be constructed to vanish, $ m_4 = m_5 = m_6 = 0 $, in contrast to
the familiar seesaw mechanism.
| [
{
"created": "Wed, 2 Jan 2002 11:06:08 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Feb 2002 13:28:31 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Krolikowski",
"Wojciech",
""
]
] | An effective texture is presented for six Majorana neutrinos, three active and three (conventional) sterile, based on a 6x6 mass matrix, whose 3x3 active--sterile component (i.e., Dirac component) is conjectured to get a fermion universal form similar to the constructed previously 3x3 mass matrix for charged leptons and 3x3 mass matrices for up and down quarks. This is true, however, when the bimaximal mixing, specific for neutrinos, is transformed out unitarily from the neutrino mass matrix. The 3x3 active--active component (i.e., lefthanded component) of neutrino 6x6 mass matrix is diagonal and gets degenerate entries. It dominates over the whole neutrino mass matrix. In such a texture, three neutrino masses are nearly degenerate, $ m_1 \simeq m_2 \simeq m_3 $, but their mass-squared differences appear hierarchical, $\Delta m^2_{21} \ll \Delta m^2_{32} \simeq \Delta m^2_{31}$, while the remaining three neutrino masses can be constructed to vanish, $ m_4 = m_5 = m_6 = 0 $, in contrast to the familiar seesaw mechanism. |
2103.13370 | Peter Stangl | Wolfgang Altmannshofer, Peter Stangl | New Physics in Rare B Decays after Moriond 2021 | 34 pages, 11 figures, 6 tables. v3: fits with 4 and 6 parameters
added, appendix on theory uncertainties added, experimental data updated,
numerics updated, discussion extended | null | 10.1140/epjc/s10052-021-09725-1 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The anomalies in rare $B$ decays endure. We present results of an updated
global analysis that takes into account the latest experimental input -- in
particular the recent results on $R_K$ and BR$(B_s \to \mu^+\mu^-)$ -- and that
qualitatively improves the treatment of theory uncertainties. Fit results are
presented for the Wilson coefficients of four-fermion contact interactions. We
find that muon specific Wilson coefficients $C_9 \simeq -0.73$ or $C_9 =
-C_{10} \simeq -0.39$ continue to give an excellent description of the data. If
only theoretically clean observables are considered, muon specific $C_{10}
\simeq 0.60$ or $C_9=-C_{10} \simeq -0.35$ improve over the Standard Model by
$\sqrt{\Delta \chi^2} \simeq 4.7\sigma$ and $\sqrt{\Delta \chi^2} \simeq
4.6\sigma$, respectively. In various new physics scenarios we provide
predictions for lepton flavor universality observables and CP asymmetries that
can be tested with more data. We update our previous combination of ATLAS, CMS,
and LHCb data on BR$(B_s \to \mu^+\mu^-)$ and BR$(B^0\to \mu^+\mu^-)$ taking
into account the full two-dimensional non-Gaussian experimental likelihoods.
| [
{
"created": "Wed, 24 Mar 2021 17:46:07 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Apr 2021 17:40:08 GMT",
"version": "v2"
},
{
"created": "Tue, 21 Sep 2021 09:58:52 GMT",
"version": "v3"
}
] | 2021-11-17 | [
[
"Altmannshofer",
"Wolfgang",
""
],
[
"Stangl",
"Peter",
""
]
] | The anomalies in rare $B$ decays endure. We present results of an updated global analysis that takes into account the latest experimental input -- in particular the recent results on $R_K$ and BR$(B_s \to \mu^+\mu^-)$ -- and that qualitatively improves the treatment of theory uncertainties. Fit results are presented for the Wilson coefficients of four-fermion contact interactions. We find that muon specific Wilson coefficients $C_9 \simeq -0.73$ or $C_9 = -C_{10} \simeq -0.39$ continue to give an excellent description of the data. If only theoretically clean observables are considered, muon specific $C_{10} \simeq 0.60$ or $C_9=-C_{10} \simeq -0.35$ improve over the Standard Model by $\sqrt{\Delta \chi^2} \simeq 4.7\sigma$ and $\sqrt{\Delta \chi^2} \simeq 4.6\sigma$, respectively. In various new physics scenarios we provide predictions for lepton flavor universality observables and CP asymmetries that can be tested with more data. We update our previous combination of ATLAS, CMS, and LHCb data on BR$(B_s \to \mu^+\mu^-)$ and BR$(B^0\to \mu^+\mu^-)$ taking into account the full two-dimensional non-Gaussian experimental likelihoods. |
hep-ph/0001195 | Satoshi Oyama | N. I. Kochelev, T. Morii and S. Oyama | Diffractive Lambda_c^+ Productions in Polarized pp Reactions and
Polarized Gluon Distribution | 9 pages, 5 figures | null | null | KOBE-FHD-99-06 | hep-ph | null | To test the model of the polarized gluon distribution $\Delta G(x, Q^2)$ in
the proton, we propose a new process, diffractive $\Lambda_c^+$ productions in
polarized $pp$ reactions, which will be observed in the forthcoming RHIC and
also the proposed HERA-$\vec {\rm N}$ experiments. The spin correlation between
the target proton and the $\Lambda_c^+$ produced in the target fragmentation
region largely depends on $\Delta G(x, Q^2)$ and thus, the process is quite
promising for testing the models of $\Delta G(x, Q^2)$.
| [
{
"created": "Wed, 19 Jan 2000 15:33:20 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kochelev",
"N. I.",
""
],
[
"Morii",
"T.",
""
],
[
"Oyama",
"S.",
""
]
] | To test the model of the polarized gluon distribution $\Delta G(x, Q^2)$ in the proton, we propose a new process, diffractive $\Lambda_c^+$ productions in polarized $pp$ reactions, which will be observed in the forthcoming RHIC and also the proposed HERA-$\vec {\rm N}$ experiments. The spin correlation between the target proton and the $\Lambda_c^+$ produced in the target fragmentation region largely depends on $\Delta G(x, Q^2)$ and thus, the process is quite promising for testing the models of $\Delta G(x, Q^2)$. |
0812.3735 | Harleen Dahiya Dr. | Harleen Dahiya, Neetika Sharma, P.K. Chatley and Manmohan Gupta | Semi-leptonic Octet Baryon Weak Axial-Vector Form Factors in the Chiral
Constitutent Quark Model | 5 pages, 2 tables. Presented at the 18th International Spin Physics
Symposium, University of Virginia, USA, October 6-11, 2008 | AIP Conf.Proc.1149:361-364,2009 | 10.1063/1.3215665 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The weak vector and axial-vector form factors have been investigated for the
semi-leptonic octet baryon decays in the chiral constituent quark model with
configuration mixing (\chiCQM_{config}). The effects of SU(3) symmetry breaking
and configuration mixing have also been investigated and the results are not
only in good agreement with existing experimental data but also show
improvement over other phenomenological models.
| [
{
"created": "Fri, 19 Dec 2008 09:51:07 GMT",
"version": "v1"
}
] | 2009-08-24 | [
[
"Dahiya",
"Harleen",
""
],
[
"Sharma",
"Neetika",
""
],
[
"Chatley",
"P. K.",
""
],
[
"Gupta",
"Manmohan",
""
]
] | The weak vector and axial-vector form factors have been investigated for the semi-leptonic octet baryon decays in the chiral constituent quark model with configuration mixing (\chiCQM_{config}). The effects of SU(3) symmetry breaking and configuration mixing have also been investigated and the results are not only in good agreement with existing experimental data but also show improvement over other phenomenological models. |
1905.12562 | David Kaiser | Rachel Nguyen, Jorinde van de Vis, Evangelos I. Sfakianakis, John T.
Giblin, Jr., and David I. Kaiser | Nonlinear Dynamics of Preheating after Multifield Inflation with
Nonminimal Couplings | 6 pages, 7 figures. References added and minor edits made to match
version to be published in Physical Review Letters | Phys. Rev. Lett. 123, 171301 (2019) | 10.1103/PhysRevLett.123.171301 | Preprint MIT-CTP/5121, Nikhef 2019-016 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the post-inflation dynamics of multifield models involving
nonminimal couplings using lattice simulations to capture significant nonlinear
effects like backreaction and rescattering. We measure the effective equation
of state and typical time-scales for the onset of thermalization, which could
affect the usual mapping between predictions for primordial perturbation
spectra and measurements of anisotropies in the cosmic microwave background
radiation. For large values of the nonminimal coupling constants, we find
efficient particle production that gives rise to nearly instantaneous
preheating. Moreover, the strong single-field attractor behavior that was
previously identified persists until the end of preheating, thereby suppressing
typical signatures of multifield models. We therefore find that predictions for
primordial observables in this class of models retain a close match to the
latest observations.
| [
{
"created": "Wed, 29 May 2019 16:14:42 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Oct 2019 02:21:17 GMT",
"version": "v2"
}
] | 2019-10-30 | [
[
"Nguyen",
"Rachel",
""
],
[
"van de Vis",
"Jorinde",
""
],
[
"Sfakianakis",
"Evangelos I.",
""
],
[
"Giblin,",
"John T.",
"Jr."
],
[
"Kaiser",
"David I.",
""
]
] | We study the post-inflation dynamics of multifield models involving nonminimal couplings using lattice simulations to capture significant nonlinear effects like backreaction and rescattering. We measure the effective equation of state and typical time-scales for the onset of thermalization, which could affect the usual mapping between predictions for primordial perturbation spectra and measurements of anisotropies in the cosmic microwave background radiation. For large values of the nonminimal coupling constants, we find efficient particle production that gives rise to nearly instantaneous preheating. Moreover, the strong single-field attractor behavior that was previously identified persists until the end of preheating, thereby suppressing typical signatures of multifield models. We therefore find that predictions for primordial observables in this class of models retain a close match to the latest observations. |
1003.2648 | Michael Kr\"amer | Herbi K. Dreiner, Michael Kr\"amer, Jonas M. Lindert, Ben O'Leary | SUSY parameter determination at the LHC using cross sections and
kinematic edges | 22 pages, 8 figures | JHEP 1004:109,2010 | 10.1007/JHEP04(2010)109 | TTK-10-24 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the determination of supersymmetric parameters at the LHC from a
global fit including cross sections and edges of kinematic distributions. For
illustration, we focus on a minimal supergravity scenario and discuss how well
it can be constrained at the LHC operating at 7 and 14 TeV collision energy,
respectively. We find that the inclusion of cross sections greatly improves the
accuracy of the SUSY parameter determination, and allows to reliably extract
model parameters even in the initial phase of LHC data taking with 7 TeV
collision energy and 1/fb integrated luminosity. Moreover, cross section
information may be essential to study more general scenarios, such as those
with non-universal gaugino masses, and distinguish them from minimal,
universal, models.
| [
{
"created": "Fri, 12 Mar 2010 22:27:43 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Dreiner",
"Herbi K.",
""
],
[
"Krämer",
"Michael",
""
],
[
"Lindert",
"Jonas M.",
""
],
[
"O'Leary",
"Ben",
""
]
] | We study the determination of supersymmetric parameters at the LHC from a global fit including cross sections and edges of kinematic distributions. For illustration, we focus on a minimal supergravity scenario and discuss how well it can be constrained at the LHC operating at 7 and 14 TeV collision energy, respectively. We find that the inclusion of cross sections greatly improves the accuracy of the SUSY parameter determination, and allows to reliably extract model parameters even in the initial phase of LHC data taking with 7 TeV collision energy and 1/fb integrated luminosity. Moreover, cross section information may be essential to study more general scenarios, such as those with non-universal gaugino masses, and distinguish them from minimal, universal, models. |
1103.5642 | Antoni Szczurek | Piotr Lebiedowicz, Roman Pasechnik and Antoni Szczurek | Measurement of exclusive production of scalar $\chi_{c0}$ meson in
proton-(anti)proton collisions via $\chi_{c0} \to \pi^{+}\pi^{-}$ decay | 16 pages, 10 figures, 2 tables | Phys.Lett.B701:434-444,2011 | 10.1016/j.physletb.2011.06.017 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a measurement of exclusive production of scalar
$\chi_{c}(0^{++})$ meson in the proton-proton collisions at LHC and RHIC and in
the proton-antiproton collisions at the Tevatron via $\chi_{c0} \to
\pi^{+}\pi^{-}$ decay. The corresponding amplitude for exclusive
double-diffractive $\chi_{c0}$ meson production was obtained within the
$k_{t}$-factorization approach including virtualities of active gluons and the
corresponding cross section is calculated with unintegrated gluon distribution
functions (UGDFs) known from the literature. The four-body $p p \to p p \pi^+
\pi^-$ reaction constitutes an irreducible background to the exclusive
$\chi_{c0}$ meson production. We calculate several differential distributions
for $pp(\bar{p}) \to pp(\bar{p})\chi_{c0}$ process including absorptive
corrections. The influence of kinematical cuts on the signal-to-background
ratio is investigated. Corresponding experimental consequences are discussed.
| [
{
"created": "Tue, 29 Mar 2011 14:00:04 GMT",
"version": "v1"
}
] | 2011-07-06 | [
[
"Lebiedowicz",
"Piotr",
""
],
[
"Pasechnik",
"Roman",
""
],
[
"Szczurek",
"Antoni",
""
]
] | We consider a measurement of exclusive production of scalar $\chi_{c}(0^{++})$ meson in the proton-proton collisions at LHC and RHIC and in the proton-antiproton collisions at the Tevatron via $\chi_{c0} \to \pi^{+}\pi^{-}$ decay. The corresponding amplitude for exclusive double-diffractive $\chi_{c0}$ meson production was obtained within the $k_{t}$-factorization approach including virtualities of active gluons and the corresponding cross section is calculated with unintegrated gluon distribution functions (UGDFs) known from the literature. The four-body $p p \to p p \pi^+ \pi^-$ reaction constitutes an irreducible background to the exclusive $\chi_{c0}$ meson production. We calculate several differential distributions for $pp(\bar{p}) \to pp(\bar{p})\chi_{c0}$ process including absorptive corrections. The influence of kinematical cuts on the signal-to-background ratio is investigated. Corresponding experimental consequences are discussed. |
hep-ph/9205243 | Aneesh V. Manohar | Elizabeth Jenkins, Aneesh V. Manohar, and Mark B. Wise | Baryons Containing a Heavy Quark as Solitons | 15 pages, uses phyzzx.tex and tables.tex, REVISED VERSION: Some of
the results have changed because of a crucial minus sign, CALT-68-1783 and
UCSD/PTH 92-17 | Nucl.Phys.B396:27-37,1993 | 10.1016/0550-3213(93)90256-O | null | hep-ph | null | The possibility of interpreting baryons containing a single heavy quark as
bound states of solitons (that arise in the nonlinear sigma model) and heavy
mesons is explored. Particular attention is paid to the parity of the bound
states and to the role of heavy quark symmetry.
| [
{
"created": "Thu, 28 May 1992 17:43:25 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Jun 1992 18:43:47 GMT",
"version": "v2"
},
{
"created": "Thu, 20 Aug 1992 23:46:52 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Jenkins",
"Elizabeth",
""
],
[
"Manohar",
"Aneesh V.",
""
],
[
"Wise",
"Mark B.",
""
]
] | The possibility of interpreting baryons containing a single heavy quark as bound states of solitons (that arise in the nonlinear sigma model) and heavy mesons is explored. Particular attention is paid to the parity of the bound states and to the role of heavy quark symmetry. |
hep-ph/0001172 | Witold Skiba | Martin Schmaltz (SLAC), Witold Skiba (UC, San Diego) | Minimal Gaugino Mediation | LaTeX, 16 pages, 4 figures, running of the bottom and tau Yukawas
included, plots revised | Phys.Rev.D62:095005,2000 | 10.1103/PhysRevD.62.095005 | SLAC-PUB-8325, UCSD/PTH-00-01 | hep-ph | null | We propose Minimal Gaugino Mediation as the simplest known solution to the
supersymmetric flavor and CP problems. The framework predicts a very minimal
structure for the soft parameters at ultra-high energies: gaugino masses are
unified and non-vanishing whereas all other soft supersymmetry breaking
parameters vanish. We show that this boundary condition naturally arises from a
small extra dimension and present a complete model which includes a new
extra-dimensional solution to the mu problem. We briefly discuss the predicted
superpartner spectrum as a function of the two parameters of the model. The
commonly ignored renormalization group evolution above the GUT scale is crucial
to the viability of Minimal Gaugino Mediation but does not introduce new model
dependence.
| [
{
"created": "Tue, 18 Jan 2000 00:15:58 GMT",
"version": "v1"
},
{
"created": "Fri, 19 May 2000 00:42:18 GMT",
"version": "v2"
}
] | 2011-05-05 | [
[
"Schmaltz",
"Martin",
"",
"SLAC"
],
[
"Skiba",
"Witold",
"",
"UC, San Diego"
]
] | We propose Minimal Gaugino Mediation as the simplest known solution to the supersymmetric flavor and CP problems. The framework predicts a very minimal structure for the soft parameters at ultra-high energies: gaugino masses are unified and non-vanishing whereas all other soft supersymmetry breaking parameters vanish. We show that this boundary condition naturally arises from a small extra dimension and present a complete model which includes a new extra-dimensional solution to the mu problem. We briefly discuss the predicted superpartner spectrum as a function of the two parameters of the model. The commonly ignored renormalization group evolution above the GUT scale is crucial to the viability of Minimal Gaugino Mediation but does not introduce new model dependence. |
hep-ph/0304278 | Ahmed Ali | A. Ali (CERN) and A.Ya. Parkhomenko (Univ. Bern) | An Analysis of the Inclusive Decay $\Upsilon (1S) \to \eta^\prime X$ and
Constraints on the $\eta^\prime$-Meson Distribution Amplitudes | 23 pages, 8 figures; use epsfig.sty; Typos corrected, numerical
analysis further refined; added an equation; to appear in the European
Physical Journal C | Eur.Phys.J.C30:183-195,2003 | 10.1140/epjc/s2003-01260-y | CERN-TH/2003-096; BUTP-2003/09 | hep-ph hep-ex | null | We calculate the $\eta^\prime$-meson energy spectrum in the decay $\Upsilon
(1S) \to \eta^\prime g g g \to \eta^\prime X$ in the leading-order perturbative
QCD in the static quark limit for the Orthoquarkonium. Our principal result is
the extraction of parameters of the $\eta^\prime g^* g$ effective vertex
function (EVF) involving a virtual and a real gluon from the available data on
the hard part of the $\eta^\prime$-meson energy spectrum. The perturbative QCD
based framework provides a good description of the available CLEO data,
allowing to constrain the lowest Gegenbauer coefficients $B^{(q)}_2$ and
$B^{(g)}_2$ of the quark-antiquark and gluonic distribution amplitudes of the
$\eta^\prime$-meson. The resulting constraints are combined with the existing
ones on these coefficients from an analysis of the $\eta-\gamma$ and
$\eta^\prime-\gamma$ transition form factors and the requirement of positivity
of the EVF, yielding $B^{(q)}_2(\mu_0^2) = -0.008 \pm 0.054$ and
$B^{(g)}_2(\mu_0^2) = 4.6 \pm 2.5$ for $\mu_0^2 = 2$ GeV$^2$. This reduces
significantly the current uncertainty on these coefficients. The resulting EFV
$F_{\eta^\prime g^* g} (p^2, 0, m_{\eta^\prime}^2)$, including the
$\eta^\prime$-meson mass effects, is presented.
| [
{
"created": "Tue, 29 Apr 2003 20:01:11 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Jun 2003 12:15:24 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Ali",
"A.",
"",
"CERN"
],
[
"Parkhomenko",
"A. Ya.",
"",
"Univ. Bern"
]
] | We calculate the $\eta^\prime$-meson energy spectrum in the decay $\Upsilon (1S) \to \eta^\prime g g g \to \eta^\prime X$ in the leading-order perturbative QCD in the static quark limit for the Orthoquarkonium. Our principal result is the extraction of parameters of the $\eta^\prime g^* g$ effective vertex function (EVF) involving a virtual and a real gluon from the available data on the hard part of the $\eta^\prime$-meson energy spectrum. The perturbative QCD based framework provides a good description of the available CLEO data, allowing to constrain the lowest Gegenbauer coefficients $B^{(q)}_2$ and $B^{(g)}_2$ of the quark-antiquark and gluonic distribution amplitudes of the $\eta^\prime$-meson. The resulting constraints are combined with the existing ones on these coefficients from an analysis of the $\eta-\gamma$ and $\eta^\prime-\gamma$ transition form factors and the requirement of positivity of the EVF, yielding $B^{(q)}_2(\mu_0^2) = -0.008 \pm 0.054$ and $B^{(g)}_2(\mu_0^2) = 4.6 \pm 2.5$ for $\mu_0^2 = 2$ GeV$^2$. This reduces significantly the current uncertainty on these coefficients. The resulting EFV $F_{\eta^\prime g^* g} (p^2, 0, m_{\eta^\prime}^2)$, including the $\eta^\prime$-meson mass effects, is presented. |
hep-ph/0503239 | Francesco Becattini | Francesco Becattini (University of Florence and INFN) | Production of multiply heavy flavoured baryons from Quark Gluon Plasma
in relativistic heavy ion collisions | 4 pages. Published version with minor corrections | Phys.Rev.Lett. 95 (2005) 022301 | 10.1103/PhysRevLett.95.022301 | null | hep-ph nucl-th | null | It is argued that in heavy ion collisions at LHC there could be a sizeable
production of baryons containing two or three heavy quarks from statistical
coalescence. This production mechanism is peculiar of Quark Gluon Plasma and
the predicted rates, in heavy ion collisions at LHC energy, exceed those from a
purely hadronic scenario, particularly for Xi_bc and Omega_ccc. Thus, besides
the interest in the discovery of these new states, enhanced ratios of these
baryons over singly heavy flavoured hadrons, like B or D, in heavy ion
collisions with respect to pp at the same energy, would be a clear indication
of kinetic equilibration of heavy quarks in the Quark Gluon Plasma.
| [
{
"created": "Wed, 23 Mar 2005 16:25:47 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Mar 2005 13:49:53 GMT",
"version": "v2"
},
{
"created": "Tue, 11 Oct 2005 13:22:12 GMT",
"version": "v3"
}
] | 2009-11-11 | [
[
"Becattini",
"Francesco",
"",
"University of Florence and INFN"
]
] | It is argued that in heavy ion collisions at LHC there could be a sizeable production of baryons containing two or three heavy quarks from statistical coalescence. This production mechanism is peculiar of Quark Gluon Plasma and the predicted rates, in heavy ion collisions at LHC energy, exceed those from a purely hadronic scenario, particularly for Xi_bc and Omega_ccc. Thus, besides the interest in the discovery of these new states, enhanced ratios of these baryons over singly heavy flavoured hadrons, like B or D, in heavy ion collisions with respect to pp at the same energy, would be a clear indication of kinetic equilibration of heavy quarks in the Quark Gluon Plasma. |
hep-ph/9501273 | null | C. Adam | THE DYSON-SCHWINGER EQUATION FOR A MODEL WITH INSTANTONS - THE SCHWINGER
MODEL | LATEX file 11 pages, no figures | Czech.J.Phys.46:893-904,1996 | 10.1007/BF01795138 | UWThPh-1994-39 | hep-ph hep-th | null | Using the exact path integral solution of the Schwinger model -- a model
where instantons are present -- the Dyson-Schwinger equation is shown to hold
by explicit computation. It turns out that the Dyson-Schwinger equation
separately holds for every instanton sector. This is due to Theta-invariance of
the Schwinger model.
| [
{
"created": "Wed, 11 Jan 1995 14:19:00 GMT",
"version": "v1"
}
] | 2011-08-17 | [
[
"Adam",
"C.",
""
]
] | Using the exact path integral solution of the Schwinger model -- a model where instantons are present -- the Dyson-Schwinger equation is shown to hold by explicit computation. It turns out that the Dyson-Schwinger equation separately holds for every instanton sector. This is due to Theta-invariance of the Schwinger model. |
hep-ph/0702108 | Tomohito Maeda | Kunio Takamatsu | Comments on the "Reply" presented in hep-ph/0701058v1 | 5 pages, no figures | null | null | null | hep-ph | null | Comments are presented on the analyses of $\pi\pi$/$K\pi$ scattering and
production processes in relation with the combined fit and Adler zero
concerning the hep-ph/0701058v1.
| [
{
"created": "Sun, 11 Feb 2007 01:17:31 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Takamatsu",
"Kunio",
""
]
] | Comments are presented on the analyses of $\pi\pi$/$K\pi$ scattering and production processes in relation with the combined fit and Adler zero concerning the hep-ph/0701058v1. |
1702.07273 | Jean-Fran\c{c}ois Fortin | Jean-Fran\c{c}ois Fortin, Nicolas Giasson, Luc Marleau | Anarchy and Neutrino Physics | 1+22 pages, 8 figures, typos fixed, added reference | null | 10.1007/JHEP04(2017)131 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The neutrino sector of a seesaw-extended Standard Model is investigated under
the anarchy hypothesis. The previously derived probability density functions
for neutrino masses and mixings, which characterize the type I-III seesaw
ensemble of $N\times N$ complex random matrices, are used to extract
information on the relevant physical parameters. For $N=2$ and $N=3$, the
distributions of the light neutrino masses, as well as the mixing angles and
phases, are obtained using numerical integration methods. A systematic
comparison with the much simpler type II seesaw ensemble is also performed to
point out the fundamental differences between the two ensembles. It is found
that the type I-III seesaw ensemble is better suited to accommodate
experimental data. Moreover, the results indicate a strong preference for the
mass splitting associated to normal hierarchy. However, since all permutations
of the singular values are found to be equally probable for a particular mass
splitting, predictions regarding the hierarchy of the mass spectrum remains out
of reach in the framework of anarchy.
| [
{
"created": "Thu, 23 Feb 2017 16:03:00 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Apr 2017 14:01:06 GMT",
"version": "v2"
},
{
"created": "Wed, 31 Jan 2018 14:34:34 GMT",
"version": "v3"
}
] | 2018-02-01 | [
[
"Fortin",
"Jean-François",
""
],
[
"Giasson",
"Nicolas",
""
],
[
"Marleau",
"Luc",
""
]
] | The neutrino sector of a seesaw-extended Standard Model is investigated under the anarchy hypothesis. The previously derived probability density functions for neutrino masses and mixings, which characterize the type I-III seesaw ensemble of $N\times N$ complex random matrices, are used to extract information on the relevant physical parameters. For $N=2$ and $N=3$, the distributions of the light neutrino masses, as well as the mixing angles and phases, are obtained using numerical integration methods. A systematic comparison with the much simpler type II seesaw ensemble is also performed to point out the fundamental differences between the two ensembles. It is found that the type I-III seesaw ensemble is better suited to accommodate experimental data. Moreover, the results indicate a strong preference for the mass splitting associated to normal hierarchy. However, since all permutations of the singular values are found to be equally probable for a particular mass splitting, predictions regarding the hierarchy of the mass spectrum remains out of reach in the framework of anarchy. |
0912.0502 | Grigory Volovik | G.E. Volovik | Topological invariants for Standard Model: from semi-metal to
topological insulator | 8 pages, 4 figures, JETP Lett. style, version published in JETP
Letters | JETP Lett.91:55-61,2010 | 10.1134/S0021364010020013 | null | hep-ph cond-mat.str-el | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider topological invariants describing semimetal (gapless) and
insulating (gapped) states of the quantum vacuum of Standard Model and possible
quantum phase transitions between these states.
| [
{
"created": "Wed, 2 Dec 2009 19:40:17 GMT",
"version": "v1"
},
{
"created": "Sat, 5 Dec 2009 13:05:46 GMT",
"version": "v2"
},
{
"created": "Fri, 11 Dec 2009 19:14:50 GMT",
"version": "v3"
},
{
"created": "Mon, 14 Dec 2009 09:58:44 GMT",
"version": "v4"
},
{
"cre... | 2014-11-20 | [
[
"Volovik",
"G. E.",
""
]
] | We consider topological invariants describing semimetal (gapless) and insulating (gapped) states of the quantum vacuum of Standard Model and possible quantum phase transitions between these states. |
hep-ph/9910505 | Martin Beneke | M. Beneke (CERN) | QCD factorization for exclusive, non-leptonic B decays | 4 pages, LaTeX, Talk presented at the `International Europhysics
Conference on High Energy Physics' (EPS99), 15-21 July 1999, Tampere, Finland | null | null | CERN-TH/99-319 | hep-ph | null | Exclusive, non-leptonic, two-body decays of B mesons simplify greatly in the
heavy quark limit. In this talk I discuss the factorized structure that holds
in this limit and some of its consequences: (a) naive factorization is
recovered in a certain limit; (b) `non-factorizable' effects are hard and can
be calculated; (c) strong interaction phases vanish in the heavy quark limit
(and can be calculated as well). As an illustration, I compute the penguin
contribution to the decay $B_d\to\pi^+\pi^-$ and its effect on the
determination of $\sin 2\alpha$.
| [
{
"created": "Wed, 27 Oct 1999 08:23:56 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Beneke",
"M.",
"",
"CERN"
]
] | Exclusive, non-leptonic, two-body decays of B mesons simplify greatly in the heavy quark limit. In this talk I discuss the factorized structure that holds in this limit and some of its consequences: (a) naive factorization is recovered in a certain limit; (b) `non-factorizable' effects are hard and can be calculated; (c) strong interaction phases vanish in the heavy quark limit (and can be calculated as well). As an illustration, I compute the penguin contribution to the decay $B_d\to\pi^+\pi^-$ and its effect on the determination of $\sin 2\alpha$. |
hep-ph/0211022 | Hector DE Vega | D. Boyanovsky, H. J. de Vega, M. Simionato | Large scale magnetogenesis from a non-equilibrium phase transition in
the radiation dominated era | LaTex, 25 pages, no figures, to appear in Phys. Rev. D | Phys.Rev. D67 (2003) 123505 | 10.1103/PhysRevD.67.123505 | null | hep-ph astro-ph | null | We study the generation of large scale primordial magnetic fields by a
cosmological phase transition during the radiation dominated era. The setting
is a theory of N charged scalar fields coupled to an abelian gauge field, that
undergoes a phase transition at a critical temperature much larger than the
electroweak scale. The dynamics after the transition features two distinct
stages: a spinodal regime dominated by linear long-wavelength instabilities,
and a scaling stage in which the non-linearities and backreaction of the scalar
fields are dominant. This second stage describes the growth of horizon sized
domains. We implement a recently introduced formulation to obtain the spectrum
of magnetic fields that includes the dissipative effects of the plasma. We find
that large scale magnetogenesis is very efficient during the scaling regime.
The ratio between the energy density on scales larger than L and that in the
background radiation r(L,T) = rho_B(L,T)/rho_{cmb}(T) is r(L,T) \sim 10^{-34}
at the Electroweak scale and r(L,T) \sim 10^{-14} at the QCD scale for L \sim 1
Mpc. The resulting spectrum is insensitive to the magnetic diffusion length. We
conjecture that a similar mechanism could be operative after the QCD chiral
phase transition.
| [
{
"created": "Sat, 2 Nov 2002 16:41:56 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Apr 2003 14:49:14 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Boyanovsky",
"D.",
""
],
[
"de Vega",
"H. J.",
""
],
[
"Simionato",
"M.",
""
]
] | We study the generation of large scale primordial magnetic fields by a cosmological phase transition during the radiation dominated era. The setting is a theory of N charged scalar fields coupled to an abelian gauge field, that undergoes a phase transition at a critical temperature much larger than the electroweak scale. The dynamics after the transition features two distinct stages: a spinodal regime dominated by linear long-wavelength instabilities, and a scaling stage in which the non-linearities and backreaction of the scalar fields are dominant. This second stage describes the growth of horizon sized domains. We implement a recently introduced formulation to obtain the spectrum of magnetic fields that includes the dissipative effects of the plasma. We find that large scale magnetogenesis is very efficient during the scaling regime. The ratio between the energy density on scales larger than L and that in the background radiation r(L,T) = rho_B(L,T)/rho_{cmb}(T) is r(L,T) \sim 10^{-34} at the Electroweak scale and r(L,T) \sim 10^{-14} at the QCD scale for L \sim 1 Mpc. The resulting spectrum is insensitive to the magnetic diffusion length. We conjecture that a similar mechanism could be operative after the QCD chiral phase transition. |
hep-ph/0109047 | Sergey Troshin | S. M. Troshin, N. E. Tyurin | Unitarity constraints and role of geometrical effects in deep-inelastic
scattering and vector-meson electroproduction | 21 pages, 8 figures, journal version, to be published in Eur. Phys.
J. C | Eur.Phys.J.C22:667-675,2002 | 10.1007/s100520100843 | null | hep-ph | null | Deep-inelastic scattering at low Bjorken x and elastic vector meson
electroproduction are analyzed on the basis of the off-shell s-channel
unitarity. We discuss behavior of the total cross-section of virtual
photon-proton scattering and obtain, in particular, that the exponent in the
power-like dependence of $\sigma^{tot}_{\gamma^* p}$ is related to the
interaction radius of a constituent quark. The explicit mass dependence of the
exponent in the power energy behavior of the vector meson electroproduction has
been obtained. Angular distributions at large momentum transfers are
considered. The energy dependence of the total cross-section of
$\gamma^*\gamma^*$-interactions is also obtained.
| [
{
"created": "Thu, 6 Sep 2001 10:57:49 GMT",
"version": "v1"
},
{
"created": "Sat, 8 Sep 2001 11:10:52 GMT",
"version": "v2"
},
{
"created": "Wed, 7 Nov 2001 10:57:30 GMT",
"version": "v3"
}
] | 2011-09-13 | [
[
"Troshin",
"S. M.",
""
],
[
"Tyurin",
"N. E.",
""
]
] | Deep-inelastic scattering at low Bjorken x and elastic vector meson electroproduction are analyzed on the basis of the off-shell s-channel unitarity. We discuss behavior of the total cross-section of virtual photon-proton scattering and obtain, in particular, that the exponent in the power-like dependence of $\sigma^{tot}_{\gamma^* p}$ is related to the interaction radius of a constituent quark. The explicit mass dependence of the exponent in the power energy behavior of the vector meson electroproduction has been obtained. Angular distributions at large momentum transfers are considered. The energy dependence of the total cross-section of $\gamma^*\gamma^*$-interactions is also obtained. |
hep-ph/9504423 | Tord Riemann | D. Bardin, P. Christova, L. Kalinovskaya and T. Riemann | Complete O($\alpha$) QED corrections to the process $ep \to eX$ in mixed
variables | 10 pages, latex, 5 figures, 2 tables, a uuencoded file containing the
latex file and figures is available via anonymous ftp at
ftp://ftp.ifh.de/pub/preprint/desy95-085.uu Section 3, 2 figures and 2 tables
have been added. The revised version will appear in Phys. Lett. B | Phys.Lett. B357 (1995) 456-463 | 10.1016/0370-2693(95)00932-B | DESY 95-085 | hep-ph | null | The complete set of ${\cal O}(\alpha)$ QED corrections with soft photon
exponentiation to the process $ep \rightarrow eX$ in mixed variables
($y=y_h,Q^2=Q_l^2$) is calculated in the quark parton model, including the
lepton-quark interference and the quarkonic corrections which were unknown so
far. The interference corrections amount to few percent or less and become
negligible at small $x$. The leading logarithmic terms proportional to
$\ln(Q^2/m_q^2)$ from radiation off quarks are discussed and the
non-logarithmic quarkonic corrections found to be negligible for almost all
experimentally accessible $x$ and $y$.
| [
{
"created": "Fri, 28 Apr 1995 13:10:45 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Jul 1995 09:29:26 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Bardin",
"D.",
""
],
[
"Christova",
"P.",
""
],
[
"Kalinovskaya",
"L.",
""
],
[
"Riemann",
"T.",
""
]
] | The complete set of ${\cal O}(\alpha)$ QED corrections with soft photon exponentiation to the process $ep \rightarrow eX$ in mixed variables ($y=y_h,Q^2=Q_l^2$) is calculated in the quark parton model, including the lepton-quark interference and the quarkonic corrections which were unknown so far. The interference corrections amount to few percent or less and become negligible at small $x$. The leading logarithmic terms proportional to $\ln(Q^2/m_q^2)$ from radiation off quarks are discussed and the non-logarithmic quarkonic corrections found to be negligible for almost all experimentally accessible $x$ and $y$. |
hep-ph/0610292 | Grzegorz Wilk | Grzegorz Wilk | Fluctuations, correlations and non-extensivity | Minireview presented at XXXVI International Symposium on
Multiparticle Dynamica, September 2-8, 2006, Paraty (RJ), Brazil; to be
published in Braz. J. Phys. (2007). Some misprints corrected | Braz.J.Phys.37:714-716,2007 | 10.1590/S0103-97332007000500009 | null | hep-ph nucl-th | null | The present status of investigations on fluctuations and correlations seen in
high energy multiparticle production processes made using the notion of
nonextensivity is reviewed.
| [
{
"created": "Mon, 23 Oct 2006 12:50:33 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Dec 2006 10:09:36 GMT",
"version": "v2"
},
{
"created": "Thu, 15 Feb 2007 14:39:24 GMT",
"version": "v3"
}
] | 2011-08-04 | [
[
"Wilk",
"Grzegorz",
""
]
] | The present status of investigations on fluctuations and correlations seen in high energy multiparticle production processes made using the notion of nonextensivity is reviewed. |
2204.04702 | Shuo Yang | Chong-Xing Yue, Shuo Yang, Han Wang and Nan Zhang | Prospects for detecting axion-like particles via the decay $Z\rightarrow
af\bar{f}$ at future $Z$ factories | 16 pages, 5 figures, submitted to Physical Review D | null | 10.1103/PhysRevD.105.115027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the prospects for detecting axion-like particles (ALPs, dubbed
as "a") via the decay $Z\rightarrow a f\bar{f}$ at future $Z$ factories.
Considering the decay channels $a\rightarrow \mu^+ \mu^-$ and $a\rightarrow b
\bar{b}$ , four types of signals $\mu^+ \mu^- /E$, $b b /E$, $e^+ e^- \mu^+
\mu^-$ and $e^+ e^- b b$ are explored. We demonstrate that these channels are
promising for detecting ALPs at $Z$ factories and obtain the sensitivity bounds
on the couplings $g_{aZZ}$ and $g_{a\gamma Z}$.
| [
{
"created": "Sun, 10 Apr 2022 14:49:12 GMT",
"version": "v1"
}
] | 2022-07-13 | [
[
"Yue",
"Chong-Xing",
""
],
[
"Yang",
"Shuo",
""
],
[
"Wang",
"Han",
""
],
[
"Zhang",
"Nan",
""
]
] | We investigate the prospects for detecting axion-like particles (ALPs, dubbed as "a") via the decay $Z\rightarrow a f\bar{f}$ at future $Z$ factories. Considering the decay channels $a\rightarrow \mu^+ \mu^-$ and $a\rightarrow b \bar{b}$ , four types of signals $\mu^+ \mu^- /E$, $b b /E$, $e^+ e^- \mu^+ \mu^-$ and $e^+ e^- b b$ are explored. We demonstrate that these channels are promising for detecting ALPs at $Z$ factories and obtain the sensitivity bounds on the couplings $g_{aZZ}$ and $g_{a\gamma Z}$. |
1905.00201 | Arindam Das | Arindam Das, Srubabati Goswami, Vishnudath K. N., Takaaki Nomura | Constraining a general U(1)$^\prime$ inverse seesaw model from vacuum
stability, dark matter and collider | typos fixed, references added, results unchanged | Phys. Rev. D 101, 055026 (2020) | 10.1103/PhysRevD.101.055026 | KIAS-P19026, OU-HET-1004 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We consider a class of gauged $U(1)$ extensions of the Standard Model (SM),
where the light neutrino masses are generated by an inverse seesaw mechanism.
In addition to the three right handed neutrinos, we add three singlet fermions
and demand an extra $Z_2$ symmetry under which, the third generations of both
of the neutral fermions are odd, which in turn gives us a stable dark matter
candidate. We express the $U(1)$ charges of all the fermions in terms of the
U(1) charges of the standard model Higgs and the new complex scalar. We study
the bounds on the parameters of the model from vacuum stability, perturbative
unitarity, dark matter relic density and direct detection constraints. We also
obtain the collider constraints on the $Z'$ mass and the $U(1)'$ gauge
coupling. Finally we compare all the bounds on the $Z'$ mass versus the $U(1)'$
gauge coupling plane.
| [
{
"created": "Wed, 1 May 2019 06:52:58 GMT",
"version": "v1"
},
{
"created": "Sat, 18 May 2019 10:04:01 GMT",
"version": "v2"
}
] | 2020-03-25 | [
[
"Das",
"Arindam",
""
],
[
"Goswami",
"Srubabati",
""
],
[
"N.",
"Vishnudath K.",
""
],
[
"Nomura",
"Takaaki",
""
]
] | We consider a class of gauged $U(1)$ extensions of the Standard Model (SM), where the light neutrino masses are generated by an inverse seesaw mechanism. In addition to the three right handed neutrinos, we add three singlet fermions and demand an extra $Z_2$ symmetry under which, the third generations of both of the neutral fermions are odd, which in turn gives us a stable dark matter candidate. We express the $U(1)$ charges of all the fermions in terms of the U(1) charges of the standard model Higgs and the new complex scalar. We study the bounds on the parameters of the model from vacuum stability, perturbative unitarity, dark matter relic density and direct detection constraints. We also obtain the collider constraints on the $Z'$ mass and the $U(1)'$ gauge coupling. Finally we compare all the bounds on the $Z'$ mass versus the $U(1)'$ gauge coupling plane. |
0712.2394 | Tiago Barreiro | T. Barreiro, B. de Carlos, E. J. Copeland and N. J. Nunes | Moduli evolution in the presence of thermal corrections | 7 pages, 5 figures. Added content, version to appear in Phys. Rev. D | Phys.Rev.D78:063502,2008 | 10.1103/PhysRevD.78.063502 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effect of thermal corrections on the evolution of moduli in
effective Supergravity models. This is motivated by previous results in the
literature suggesting that these corrections could alter and, even, erase the
presence of a minimum in the zero temperature potential, something that would
have disastrous consequences in these particular models. We show that, in a
representative sample of flux compactification constructions, this need not be
the case, although we find that the inclusion of thermal corrections can
dramatically decrease the region of initial conditions for which the moduli are
stabilised. Moreover, the bounds on the reheating temperature coming from
demanding that the full, finite temperature potential, has a minimum can be
considerably relaxed given the slow pace at which the evolution proceeds.
| [
{
"created": "Fri, 14 Dec 2007 17:04:06 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Sep 2008 15:50:23 GMT",
"version": "v2"
}
] | 2009-02-20 | [
[
"Barreiro",
"T.",
""
],
[
"de Carlos",
"B.",
""
],
[
"Copeland",
"E. J.",
""
],
[
"Nunes",
"N. J.",
""
]
] | We study the effect of thermal corrections on the evolution of moduli in effective Supergravity models. This is motivated by previous results in the literature suggesting that these corrections could alter and, even, erase the presence of a minimum in the zero temperature potential, something that would have disastrous consequences in these particular models. We show that, in a representative sample of flux compactification constructions, this need not be the case, although we find that the inclusion of thermal corrections can dramatically decrease the region of initial conditions for which the moduli are stabilised. Moreover, the bounds on the reheating temperature coming from demanding that the full, finite temperature potential, has a minimum can be considerably relaxed given the slow pace at which the evolution proceeds. |
1305.3729 | Alan Cornell | Ammar Abdalgabar and A. S. Cornell | Evolution of Yukawa Couplings and Quark Flavour Mixings in the 5D MSSM | 6 pages, 6 figures, to appear in the proceedings for the Kruger2012
workshop | null | 10.1088/1742-6596/455/1/012050 | WITS-CTP-111 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The evolution equations of the Yukawa couplings and quark mixings are derived
for the one-loop renormalization group equations in the 5D Minimal
Supersymmetric Standard Model on an {$S^1 / Z_2$} orbifold. Different
possibilities for the matter fields are discussed such as the cases of bulk
propagating or brane localised fields. We discuss in both cases the evolution
of the mass ratios and the implications for the mixing angles.
| [
{
"created": "Thu, 16 May 2013 09:25:20 GMT",
"version": "v1"
}
] | 2015-06-15 | [
[
"Abdalgabar",
"Ammar",
""
],
[
"Cornell",
"A. S.",
""
]
] | The evolution equations of the Yukawa couplings and quark mixings are derived for the one-loop renormalization group equations in the 5D Minimal Supersymmetric Standard Model on an {$S^1 / Z_2$} orbifold. Different possibilities for the matter fields are discussed such as the cases of bulk propagating or brane localised fields. We discuss in both cases the evolution of the mass ratios and the implications for the mixing angles. |
hep-ph/9607485 | null | J.A. Coarasa, David Garcia, Jaume Guasch, Ricardo A. Jimenez, Joan
Sola | Quantum effects on $t\to H^{+} b$ in the MSSM: a window to ``virtual''
supersymmetry? | 60 pages, LaTeX, 25 figs included as a separate file, full postscript
version avaliable at ftp://ftp.ifae.es/preprint/ft/uabft397.ps . In this
improved version we give an extended discussion of our renormalization
framework and of the numerical analysis. Two additional figures are included.
Some missprints have been corrected | Eur.Phys.J.C2:373-392,1998 | 10.1007/s100520050148 | UAB-FT-397 | hep-ph | null | We analyze the one-loop effects (strong and electroweak) on the
unconventional top quark decay mode $t\rightarrow H^{+} b$ within the MSSM. The
results are presented in the on-shell renormalization scheme with a physically
well motivated definition of $\tan\beta$. The study of this process at the
quantum level is useful to unravel the potential supersymmetric nature of the
charged Higgs emerging from that decay. As compared with the standard mode
$t\rightarrow W^{+} b$, the corrections to $t\rightarrow H^{+} b$ are large,
slowly decoupling and persist at a sizeable level even for all sparticle masses
well above the LEP 200 discovery range. As a matter of fact, the potential size
of the SUSY effects, which amount to corrections of several ten percent, could
counterbalance the standard QCD corrections and even make them to appear with
the ``wrong'' sign. Therefore, if the charged Higgs decay of the top quark is
kinematically allowed -a possibility which is not excluded by the recent
measurements of the branching ratio $BR(t\rightarrow W^{+} b)$ at the Tevatron
- it could be an invaluable laboratory to search for ``virtual'' supersymmetry.
While a first significant test of these effects could possibly be performed at
the upgraded Tevatron, a more precise verification would most likely be carried
out in future experiments at the LHC.
| [
{
"created": "Wed, 31 Jul 1996 22:15:30 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Oct 1996 07:24:17 GMT",
"version": "v2"
}
] | 2016-09-06 | [
[
"Coarasa",
"J. A.",
""
],
[
"Garcia",
"David",
""
],
[
"Guasch",
"Jaume",
""
],
[
"Jimenez",
"Ricardo A.",
""
],
[
"Sola",
"Joan",
""
]
] | We analyze the one-loop effects (strong and electroweak) on the unconventional top quark decay mode $t\rightarrow H^{+} b$ within the MSSM. The results are presented in the on-shell renormalization scheme with a physically well motivated definition of $\tan\beta$. The study of this process at the quantum level is useful to unravel the potential supersymmetric nature of the charged Higgs emerging from that decay. As compared with the standard mode $t\rightarrow W^{+} b$, the corrections to $t\rightarrow H^{+} b$ are large, slowly decoupling and persist at a sizeable level even for all sparticle masses well above the LEP 200 discovery range. As a matter of fact, the potential size of the SUSY effects, which amount to corrections of several ten percent, could counterbalance the standard QCD corrections and even make them to appear with the ``wrong'' sign. Therefore, if the charged Higgs decay of the top quark is kinematically allowed -a possibility which is not excluded by the recent measurements of the branching ratio $BR(t\rightarrow W^{+} b)$ at the Tevatron - it could be an invaluable laboratory to search for ``virtual'' supersymmetry. While a first significant test of these effects could possibly be performed at the upgraded Tevatron, a more precise verification would most likely be carried out in future experiments at the LHC. |
1809.09115 | Vedran Brdar | Vedran Brdar, Alexei Yu. Smirnov | Low Scale Left-Right Symmetry and Naturally Small Neutrino Mass | 22 pages, 3 figures; comments and references added | JHEP 1902 (2019) 045 | 10.1007/JHEP02(2019)045 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the low scale ($10$ - $100$ TeV) left-right symmetric model with
"naturally" small neutrino masses generated through the inverse seesaw
mechanism. The Dirac neutrino mass terms are taken to be similar to the masses
of charged leptons and quarks in order to satisfy the quark-lepton similarity
condition. The inverse seesaw implies the existence of fermion singlets $S$
with Majorana mass terms as well as the "left" and "right" Higgs doublets.
These doublets provide the portal for $S$ and break the left-right symmetry.
The inverse seesaw allows to realize a scenario in which the large lepton
mixing originates from the Majorana mass matrix of $S$ fields which has certain
symmetry. The model contains heavy pseudo-Dirac fermions, formed by $S$ and the
right-handed neutrinos, which have masses in the $1$ GeV - $100$ TeV range and
can be searched for at current and future colliders such as LHC and FCC-ee as
well as in SHiP and DUNE experiments. Their contribution to neutrinoless double
beta decay is unobservable. The radiative corrections to the mass of the Higgs
boson and the possibility for generating the baryon asymmetry of the Universe
are discussed. Modification of the model with two singlets ($S_L$ and $S_R$)
per generation can provide a viable keV-scale dark matter candidate.
| [
{
"created": "Mon, 24 Sep 2018 18:00:02 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Oct 2018 12:38:44 GMT",
"version": "v2"
},
{
"created": "Wed, 13 Feb 2019 11:00:52 GMT",
"version": "v3"
}
] | 2019-02-14 | [
[
"Brdar",
"Vedran",
""
],
[
"Smirnov",
"Alexei Yu.",
""
]
] | We consider the low scale ($10$ - $100$ TeV) left-right symmetric model with "naturally" small neutrino masses generated through the inverse seesaw mechanism. The Dirac neutrino mass terms are taken to be similar to the masses of charged leptons and quarks in order to satisfy the quark-lepton similarity condition. The inverse seesaw implies the existence of fermion singlets $S$ with Majorana mass terms as well as the "left" and "right" Higgs doublets. These doublets provide the portal for $S$ and break the left-right symmetry. The inverse seesaw allows to realize a scenario in which the large lepton mixing originates from the Majorana mass matrix of $S$ fields which has certain symmetry. The model contains heavy pseudo-Dirac fermions, formed by $S$ and the right-handed neutrinos, which have masses in the $1$ GeV - $100$ TeV range and can be searched for at current and future colliders such as LHC and FCC-ee as well as in SHiP and DUNE experiments. Their contribution to neutrinoless double beta decay is unobservable. The radiative corrections to the mass of the Higgs boson and the possibility for generating the baryon asymmetry of the Universe are discussed. Modification of the model with two singlets ($S_L$ and $S_R$) per generation can provide a viable keV-scale dark matter candidate. |
hep-ph/0202141 | null | Prem P. Srivastava (Fermilab and UERJ), Stanley J. Brodsky (SLAC) | A Unitary and Renormalizable Theory of the Standard Model in Ghost-Free
Light-Cone Gauge | Latex, 36 pages | Phys.Rev.D66:045019,2002 | 10.1103/PhysRevD.66.045019 | SLAC-PUB-9137, FERMILAB-Pub-02/020-T | hep-ph hep-th nucl-th | null | Light-front (LF) quantization in light-cone (LC) gauge is used to construct a
unitary and simultaneously renormalizable theory of the Standard Model. The
framework derived earlier for QCD is extended to the Glashow, Weinberg, and
Salam (GWS) model of electroweak interaction theory. The Lorentz condition is
automatically satisfied in LF-quantized QCD in the LC gauge for the free
massless gauge field. In the GWS model, with the spontaneous symmetry breaking
present, we find that the 't Hooft condition accompanies the LC gauge condition
corresponding to the massive vector boson. The two transverse polarization
vectors for the massive vector boson may be chosen to be the same as found in
QCD. The non-transverse and linearly independent third polarization vector is
found to be parallel to the gauge direction. The corresponding sum over
polarizations in the Standard model, indicated by $K_{\mu\nu}(k),$ has several
simplifying properties similar to the polarization sum $D_{\mu\nu}(k)$ in QCD.
The framework is ghost-free, and the interaction Hamiltonian of electroweak
theory can be expressed in a form resembling that of covariant theory, except
for few additional instantaneous interactions which can be treated
systematically. The LF formulation also provides a transparent discussion of
the Goldstone Boson (or Electroweak) Equivalence Theorem, as the illustrations
show.
| [
{
"created": "Fri, 15 Feb 2002 00:40:18 GMT",
"version": "v1"
}
] | 2009-09-11 | [
[
"Srivastava",
"Prem P.",
"",
"Fermilab and UERJ"
],
[
"Brodsky",
"Stanley J.",
"",
"SLAC"
]
] | Light-front (LF) quantization in light-cone (LC) gauge is used to construct a unitary and simultaneously renormalizable theory of the Standard Model. The framework derived earlier for QCD is extended to the Glashow, Weinberg, and Salam (GWS) model of electroweak interaction theory. The Lorentz condition is automatically satisfied in LF-quantized QCD in the LC gauge for the free massless gauge field. In the GWS model, with the spontaneous symmetry breaking present, we find that the 't Hooft condition accompanies the LC gauge condition corresponding to the massive vector boson. The two transverse polarization vectors for the massive vector boson may be chosen to be the same as found in QCD. The non-transverse and linearly independent third polarization vector is found to be parallel to the gauge direction. The corresponding sum over polarizations in the Standard model, indicated by $K_{\mu\nu}(k),$ has several simplifying properties similar to the polarization sum $D_{\mu\nu}(k)$ in QCD. The framework is ghost-free, and the interaction Hamiltonian of electroweak theory can be expressed in a form resembling that of covariant theory, except for few additional instantaneous interactions which can be treated systematically. The LF formulation also provides a transparent discussion of the Goldstone Boson (or Electroweak) Equivalence Theorem, as the illustrations show. |
2308.14538 | Sa Wang | Sa Wang, Yao Li, Shuwan Shen, Ben-Wei Zhang, Enke Wang | Production of the heavy-flavour decay lepton in high-energy nuclear
collisions | 11 pages, 8 figures | null | null | null | hep-ph hep-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | This paper presents a theoretical study on the production of the
heavy-flavour decay lepton (HFL) in high-energy nuclear collisions at the LHC.
The pp-baseline is calculated by the FONLL program, which matches the
next-to-leading order pQCD calculation with the next-to-leading-log large-$p_T$
resummation. The in-medium propagation of heavy quarks is driven by the
modified Langevin equations, which consider both the elastic and inelastic
partonic interactions. We propose a method to separate the respective influence
of the five factors, such as pp-spectra, the cold nuclear matter (CNM) effects,
in-medium energy loss (E-loss), fragmentation functions (FFs), and decay
channels, which may contribute to the larger $R_{AA}$ of HFL $\leftarrow b$
compared to that of HFL $\leftarrow c$ in nucleus-nucleus collisions. Based on
quantitative analysis, we demonstrate that different decay channels of charm-
and bottom-hadrons play an important role at $p_T<$5 GeV, while the
mass-dependent E-loss dominates the higher $p_T$ region. It is also found that
the influences of the CNM effects and FFs are insignificant, while different
initial pp-spectra of charm and bottom quarks have a considerable impact at
$p_T>$ 3 GeV. Furthermore, we explore the path-length dependence of jet
quenching by comparing the HFL $R_{AA}$ in two different collision systems. Our
investigations show smaller HFL $R_{AA}$ in Pb+Pb than that in Xe+Xe within the
same centrality bin, which is consistent with the ALICE data. The longer
propagation time and more effective energy loss of heavy quarks in Pb+Pb
collisions play critical roles in the stronger yield suppression of the HFL
compared to that in Xe+Xe. In addition, we observe a scaling behaviour of the
HFL $R_{AA}$ in Xe+Xe and Pb+Pb collisions.
| [
{
"created": "Mon, 28 Aug 2023 12:49:24 GMT",
"version": "v1"
}
] | 2023-08-29 | [
[
"Wang",
"Sa",
""
],
[
"Li",
"Yao",
""
],
[
"Shen",
"Shuwan",
""
],
[
"Zhang",
"Ben-Wei",
""
],
[
"Wang",
"Enke",
""
]
] | This paper presents a theoretical study on the production of the heavy-flavour decay lepton (HFL) in high-energy nuclear collisions at the LHC. The pp-baseline is calculated by the FONLL program, which matches the next-to-leading order pQCD calculation with the next-to-leading-log large-$p_T$ resummation. The in-medium propagation of heavy quarks is driven by the modified Langevin equations, which consider both the elastic and inelastic partonic interactions. We propose a method to separate the respective influence of the five factors, such as pp-spectra, the cold nuclear matter (CNM) effects, in-medium energy loss (E-loss), fragmentation functions (FFs), and decay channels, which may contribute to the larger $R_{AA}$ of HFL $\leftarrow b$ compared to that of HFL $\leftarrow c$ in nucleus-nucleus collisions. Based on quantitative analysis, we demonstrate that different decay channels of charm- and bottom-hadrons play an important role at $p_T<$5 GeV, while the mass-dependent E-loss dominates the higher $p_T$ region. It is also found that the influences of the CNM effects and FFs are insignificant, while different initial pp-spectra of charm and bottom quarks have a considerable impact at $p_T>$ 3 GeV. Furthermore, we explore the path-length dependence of jet quenching by comparing the HFL $R_{AA}$ in two different collision systems. Our investigations show smaller HFL $R_{AA}$ in Pb+Pb than that in Xe+Xe within the same centrality bin, which is consistent with the ALICE data. The longer propagation time and more effective energy loss of heavy quarks in Pb+Pb collisions play critical roles in the stronger yield suppression of the HFL compared to that in Xe+Xe. In addition, we observe a scaling behaviour of the HFL $R_{AA}$ in Xe+Xe and Pb+Pb collisions. |
hep-ph/0703295 | Hee-Jung Lee | Hee-Jung Lee | Light scalar mesons as tetraquarks within QCD Sum Rules | 4 pages, 1 figure, Talk at the Yukawa International Seminar (YKIS)
2006, "New frontiers in QCD", Kyoto, Japan | Prog.Theor.Phys.Suppl.168:190-193,2007 | 10.1143/PTPS.168.190 | null | hep-ph | null | We examine the interpretation of the light scalar meson nonet as tetraquark
states using QCD sum rules. With the interpolating current for the tetraquark
states composed of scalar diquark and scalar antidiquark, first, we construct
the QCD sum rules by means of the operator product expansion up to the
operators of dimension 8 and show that there is no evidence of the coupling of
the tetraquark states to the light scalar meson nonet. In order to have a
stable sum rule, we propose a "good" interpolating current for the tetraquarks
based on chirality arguments which includes scalar and pseudoscalar
diquark--antidiquarks with equal weights. In particular, for the lowest
tetraquark $\sigma$--meson, we perform detail analysis of the QCD sum rule and
obtain mass for the $\sigma(600)$ around 780 MeV.
| [
{
"created": "Wed, 28 Mar 2007 04:25:50 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Lee",
"Hee-Jung",
""
]
] | We examine the interpretation of the light scalar meson nonet as tetraquark states using QCD sum rules. With the interpolating current for the tetraquark states composed of scalar diquark and scalar antidiquark, first, we construct the QCD sum rules by means of the operator product expansion up to the operators of dimension 8 and show that there is no evidence of the coupling of the tetraquark states to the light scalar meson nonet. In order to have a stable sum rule, we propose a "good" interpolating current for the tetraquarks based on chirality arguments which includes scalar and pseudoscalar diquark--antidiquarks with equal weights. In particular, for the lowest tetraquark $\sigma$--meson, we perform detail analysis of the QCD sum rule and obtain mass for the $\sigma(600)$ around 780 MeV. |
hep-ph/9703259 | Hitoshi Murayama | Nima Arkani-Hamed and Hitoshi Murayama (UC Berkeley, LBNL) | Can The Supersymmetric Flavor Problem Decouple? | LaTeX, 10 pages, three EPS figures | Phys.Rev.D56:6733-6737,1997 | 10.1103/PhysRevD.56.R6733 | LBNL-4-0077, UCB-PTH-97/01 | hep-ph | null | It has been argued that the squarks and sleptons of the first and second
generations can be relatively heavy without destabilizing the weak scale,
thereby improving the situation with too-large flavor-changing neutral current
(FCNC) and CP violating processes. In theories where the soft supersymmetry
breaking parameters are generated at a high scale (such as the Planck scale),
we show that such a mass spectrum tends to drive the scalar top mass squared
$m_{\tilde{Q}_3}^2$ negative from two-loop renormalization group evolution.
Even ignoring CP violation and allowing $O(\lambda) \sim .22$ alignment, the
first two generation scalars must be heavier than 22 TeV to suppress FCNC. This
in turn requires the boundary condition on $m_{\tilde{Q}_3} > 4 TeV$ to avoid
negative $m_{\tilde{Q}_3}^2$ at the weak scale. Some of the models in the
literature employing the anomalous U(1) in string theory are excluded by our
analysis.
| [
{
"created": "Fri, 7 Mar 1997 00:21:19 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Arkani-Hamed",
"Nima",
"",
"UC Berkeley, LBNL"
],
[
"Murayama",
"Hitoshi",
"",
"UC Berkeley, LBNL"
]
] | It has been argued that the squarks and sleptons of the first and second generations can be relatively heavy without destabilizing the weak scale, thereby improving the situation with too-large flavor-changing neutral current (FCNC) and CP violating processes. In theories where the soft supersymmetry breaking parameters are generated at a high scale (such as the Planck scale), we show that such a mass spectrum tends to drive the scalar top mass squared $m_{\tilde{Q}_3}^2$ negative from two-loop renormalization group evolution. Even ignoring CP violation and allowing $O(\lambda) \sim .22$ alignment, the first two generation scalars must be heavier than 22 TeV to suppress FCNC. This in turn requires the boundary condition on $m_{\tilde{Q}_3} > 4 TeV$ to avoid negative $m_{\tilde{Q}_3}^2$ at the weak scale. Some of the models in the literature employing the anomalous U(1) in string theory are excluded by our analysis. |
2405.01712 | Magno Machado | L.S. Moriggi, G.S. Ramos, M.V.T. Machado | Multiplicity dependence of the $p_T$-spectra for charged particles and
its relationship with partonic entropy | 11 pages, 7 figures. Version to be published in Physical Review D | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We investigate the multiplicity dependence of the transverse momentum $p_T$
spectra of hadrons produced in high-energy collisions. We propose that the
partonic distribution be parameterized by its non-extensive entropy and the
parton saturation scale $Q_s(x)$. These two variables can be identified from
the produced charged hadron distributions and provide important information on
the gluon dynamics at the moment of interaction. From this perspective we
interpret data from different ALICE multiplicity classes at $\sqrt{s}= 13$ TeV
and $\sqrt{s}= 5.02$ TeV. A multiplicity dependent scaling function is
presented and the dependence of the interaction area on multiplicity is also
investigated.
| [
{
"created": "Thu, 2 May 2024 20:17:48 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Jul 2024 22:37:12 GMT",
"version": "v2"
}
] | 2024-07-10 | [
[
"Moriggi",
"L. S.",
""
],
[
"Ramos",
"G. S.",
""
],
[
"Machado",
"M. V. T.",
""
]
] | We investigate the multiplicity dependence of the transverse momentum $p_T$ spectra of hadrons produced in high-energy collisions. We propose that the partonic distribution be parameterized by its non-extensive entropy and the parton saturation scale $Q_s(x)$. These two variables can be identified from the produced charged hadron distributions and provide important information on the gluon dynamics at the moment of interaction. From this perspective we interpret data from different ALICE multiplicity classes at $\sqrt{s}= 13$ TeV and $\sqrt{s}= 5.02$ TeV. A multiplicity dependent scaling function is presented and the dependence of the interaction area on multiplicity is also investigated. |
hep-ph/0210348 | Anders Tranberg | J. Smit and A. Tranberg | Chern-Simons number asymmetry from CP-violation during tachyonic
preheating | 5 pages, 10 figures, to appear in the proceedings of SEWM2002.
Modified presentation of final result. Results unchanged | null | 10.1142/9789812704498_0071 | ITFA-2002-45 | hep-ph hep-lat | null | We consider the creation of non-zero Chern-Simons number in a model of the
early Universe, where the Higgs field experiences a fast quench at the end of
inflation. We perform numerical lattice simulations in the Abelian Higgs model
in 1+1 dimensions and in the SU(2)-Higgs model in 3+1 dimensions with an added
effective CP-violating term. We also comment on the appropriate choice of
vacuum initial conditions for classical simulations.
| [
{
"created": "Fri, 25 Oct 2002 09:49:27 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Nov 2002 11:34:15 GMT",
"version": "v2"
}
] | 2017-08-23 | [
[
"Smit",
"J.",
""
],
[
"Tranberg",
"A.",
""
]
] | We consider the creation of non-zero Chern-Simons number in a model of the early Universe, where the Higgs field experiences a fast quench at the end of inflation. We perform numerical lattice simulations in the Abelian Higgs model in 1+1 dimensions and in the SU(2)-Higgs model in 3+1 dimensions with an added effective CP-violating term. We also comment on the appropriate choice of vacuum initial conditions for classical simulations. |
2002.00036 | Gongjun Choi | Gongjun Choi, Motoo Suzuki, Tsutomu T. Yanagida | Degenerate Sub-keV Fermion Dark Matter from a Solution to the Hubble
Tension | 7 pages, 2 figures, version published in PRD | Phys. Rev. D 101, 075031 (2020) | 10.1103/PhysRevD.101.075031 | null | hep-ph astro-ph.CO astro-ph.GA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a dark sector model addressing both the Hubble tension and the
core-cusp problem. The model is based on a hidden Abelian gauge symmetry group
with some chiral fermions required by the anomaly cancellation conditions,
producing a candidate for the decaying fermion dark matter as a solution to the
Hubble tension. Moreover, the sub-keV mass regime and the thermal history of
the dark sector help the dark matter candidate resolve the core-cusp problem
occurring in the standard $\Lambda$CDM cosmology.
| [
{
"created": "Fri, 31 Jan 2020 19:47:24 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Apr 2020 14:47:37 GMT",
"version": "v2"
}
] | 2020-04-22 | [
[
"Choi",
"Gongjun",
""
],
[
"Suzuki",
"Motoo",
""
],
[
"Yanagida",
"Tsutomu T.",
""
]
] | We present a dark sector model addressing both the Hubble tension and the core-cusp problem. The model is based on a hidden Abelian gauge symmetry group with some chiral fermions required by the anomaly cancellation conditions, producing a candidate for the decaying fermion dark matter as a solution to the Hubble tension. Moreover, the sub-keV mass regime and the thermal history of the dark sector help the dark matter candidate resolve the core-cusp problem occurring in the standard $\Lambda$CDM cosmology. |
2301.12546 | Howard Baer | Howard Baer, Vernon Barger and Robert Wiley Deal | Dark matter and dark radiation from the early universe with a modulus
coupled to the PQMSSM | 40 pages including 29 .png figures | null | 10.1007/JHEP06(2023)083 | OU-HEP-230204 | hep-ph astro-ph.HE | http://creativecommons.org/licenses/by/4.0/ | The supersymmetrized DFSZ axion model is especially compelling in that it
contains 1. the SUSY solution to the gauge hierarchy problem, 2. the
Peccei-Quinn (PQ) solution to the strong CP problem and 3. the Kim-Nilles
solution to the SUSY mu problem. In a string setting, where a discrete
R-symmetry ({\bf Z}_{24}^R for example) may emerge from the compactification
process, a high-quality accidental axion (accion) can emerge from the
accidental, approximate remnant global U(1)_{PQ} symmetry where the decay
constant f_a is linked to the SUSY breaking scale, and is within the
cosmological sweet zone. In this setup, one also expects the presence of
stringy remnant moduli fields \phi_i. Here, we consider the situation of a
single light modulus \phi coupled to the PQMSSM in the early universe, with
mixed axion plus higgsino-like WIMP dark matter. We evaluate dark matter and
dark radiation production via nine coupled Boltzmann equations and assess the
severity of the cosmological moduli problem (CMP) along with dark matter and
dark radiation production rates. We find that typically the light modulus mass
should be m_{\phi}>~ 10^4 TeV to avoid the moduli-induced dark matter
overproduction problem. If one is able to (anthropically) tune the modulus
field amplitude, we find a value of \phi_0 <~ 10^{-7}m_P would be required to
solve the overall CMP.
| [
{
"created": "Sun, 29 Jan 2023 21:29:09 GMT",
"version": "v1"
}
] | 2023-07-05 | [
[
"Baer",
"Howard",
""
],
[
"Barger",
"Vernon",
""
],
[
"Deal",
"Robert Wiley",
""
]
] | The supersymmetrized DFSZ axion model is especially compelling in that it contains 1. the SUSY solution to the gauge hierarchy problem, 2. the Peccei-Quinn (PQ) solution to the strong CP problem and 3. the Kim-Nilles solution to the SUSY mu problem. In a string setting, where a discrete R-symmetry ({\bf Z}_{24}^R for example) may emerge from the compactification process, a high-quality accidental axion (accion) can emerge from the accidental, approximate remnant global U(1)_{PQ} symmetry where the decay constant f_a is linked to the SUSY breaking scale, and is within the cosmological sweet zone. In this setup, one also expects the presence of stringy remnant moduli fields \phi_i. Here, we consider the situation of a single light modulus \phi coupled to the PQMSSM in the early universe, with mixed axion plus higgsino-like WIMP dark matter. We evaluate dark matter and dark radiation production via nine coupled Boltzmann equations and assess the severity of the cosmological moduli problem (CMP) along with dark matter and dark radiation production rates. We find that typically the light modulus mass should be m_{\phi}>~ 10^4 TeV to avoid the moduli-induced dark matter overproduction problem. If one is able to (anthropically) tune the modulus field amplitude, we find a value of \phi_0 <~ 10^{-7}m_P would be required to solve the overall CMP. |
1907.02910 | Riccardo Catena | Riccardo Catena, K{\aa}re Fridell and Martin B. Krauss | Non-relativistic Effective Interactions of Spin 1 Dark Matter | 24 pages, 2 figures and 2 tables | null | 10.1007/JHEP08(2019)030 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the non-relativistic reduction of simplified models for spin 1
dark matter (DM) with the aim of identifying features in the phenomenology of
DM-quark interactions which are specific to vector DM. In the case of DM-quark
interactions mediated by a spin 1 particle, we find two DM-nucleon interaction
operators arising from the non-relativistic reduction of simplified models for
spin 1 DM that are specific to spin 1 DM, and which were not considered in
previous studies. They are quadratic in the momentum transfer, linear in a
symmetric combination of polarisation vectors for the DM particle, and arise
from simplified models which do not generate momentum transfer independent
operators as leading interactions in the non-relativistic expansion of
DM-nucleon scattering amplitudes. Within these simplified models, the new
operators cannot be neglected when computing DM signals at direct detection
experiments. For example, we find that nuclear recoil energy spectra computed
by including or neglecting the new operators can differ by up to one order of
magnitude for nuclear recoil energies larger than about 20 keV and DM masses
below $50$ GeV. Furthermore, the shape of the expected nuclear recoil spectra
depends significantly on whether the new operators are taken into account or
not. Finally, neglecting the contribution to DM direct detection signals from
the new operators leads to inaccurate conclusions when assessing the
compatibility of a future direct detection signal with CMB constraints on the
DM relic density, especially when the number of signal events is small, e.g.
$\mathcal{O}(1)$.
| [
{
"created": "Fri, 5 Jul 2019 16:16:17 GMT",
"version": "v1"
}
] | 2019-09-04 | [
[
"Catena",
"Riccardo",
""
],
[
"Fridell",
"Kåre",
""
],
[
"Krauss",
"Martin B.",
""
]
] | We investigate the non-relativistic reduction of simplified models for spin 1 dark matter (DM) with the aim of identifying features in the phenomenology of DM-quark interactions which are specific to vector DM. In the case of DM-quark interactions mediated by a spin 1 particle, we find two DM-nucleon interaction operators arising from the non-relativistic reduction of simplified models for spin 1 DM that are specific to spin 1 DM, and which were not considered in previous studies. They are quadratic in the momentum transfer, linear in a symmetric combination of polarisation vectors for the DM particle, and arise from simplified models which do not generate momentum transfer independent operators as leading interactions in the non-relativistic expansion of DM-nucleon scattering amplitudes. Within these simplified models, the new operators cannot be neglected when computing DM signals at direct detection experiments. For example, we find that nuclear recoil energy spectra computed by including or neglecting the new operators can differ by up to one order of magnitude for nuclear recoil energies larger than about 20 keV and DM masses below $50$ GeV. Furthermore, the shape of the expected nuclear recoil spectra depends significantly on whether the new operators are taken into account or not. Finally, neglecting the contribution to DM direct detection signals from the new operators leads to inaccurate conclusions when assessing the compatibility of a future direct detection signal with CMB constraints on the DM relic density, especially when the number of signal events is small, e.g. $\mathcal{O}(1)$. |
1010.0171 | Daniele Dominici | Elena Accomando, Stefania De Curtis, Daniele Dominici and Luca Fedeli | Z' production at the LHC in the four-site Higgsless model | Latex file, 33 pages, 12 figures | Phys.Rev.D83:015012,2011 | 10.1103/PhysRevD.83.015012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the phenomenology of the neutral gauge sector of the four-site
Higgsless model, based on the SU(2)_L x SU(2)_1 x SU(2)_2 x U(1)_Y gauge
symmetry, at present colliders. The model predicts the existence of two neutral
and four charged extra gauge bosons, Z_{1,2} and W^\pm_{1,2}. We expand and
update a previous study, by concentrating on the neutral sector. We derive new
limits on Z_{1,2}-boson masses and couplings from recent direct searches at the
Tevatron. We moreover estimate the discovery potential at the Tevatron with a
project luminosity L=10 fb^{-1}, and at the 7 TeV LHC with L=1 fb^{-1}. In
contrast to other Higgsless theories characterized by almost fermiophobic extra
gauge bosons, the four-site model allows sizeable Z_{1,2}-boson couplings to SM
fermions. Owing to this feature, we find that in the next two years the extra
Z_{1,2}-bosons could be discovered in the favoured Drell-Yan channel at the 7
TeV LHC for Z_{1,2} masses in the TeV region, depending on model parameters.
| [
{
"created": "Fri, 1 Oct 2010 14:29:02 GMT",
"version": "v1"
}
] | 2011-02-25 | [
[
"Accomando",
"Elena",
""
],
[
"De Curtis",
"Stefania",
""
],
[
"Dominici",
"Daniele",
""
],
[
"Fedeli",
"Luca",
""
]
] | We study the phenomenology of the neutral gauge sector of the four-site Higgsless model, based on the SU(2)_L x SU(2)_1 x SU(2)_2 x U(1)_Y gauge symmetry, at present colliders. The model predicts the existence of two neutral and four charged extra gauge bosons, Z_{1,2} and W^\pm_{1,2}. We expand and update a previous study, by concentrating on the neutral sector. We derive new limits on Z_{1,2}-boson masses and couplings from recent direct searches at the Tevatron. We moreover estimate the discovery potential at the Tevatron with a project luminosity L=10 fb^{-1}, and at the 7 TeV LHC with L=1 fb^{-1}. In contrast to other Higgsless theories characterized by almost fermiophobic extra gauge bosons, the four-site model allows sizeable Z_{1,2}-boson couplings to SM fermions. Owing to this feature, we find that in the next two years the extra Z_{1,2}-bosons could be discovered in the favoured Drell-Yan channel at the 7 TeV LHC for Z_{1,2} masses in the TeV region, depending on model parameters. |
1403.5404 | Nan Jiang | Nan Jiang, Xiao-Lin Chen, Shi-Lin Zhu | Mass and axial charge of heavy baryons | null | Phys. Rev. D 90, 074011 (2014) | 10.1103/PhysRevD.90.074011 | null | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the antitriplet and sextet heavy baryon systems with $J^P=
\frac{1}{2}^+, \frac{3}{2}^+$ in the framework of the heavy baryon chiral
perturbation theory. We first calculate the chiral corrections to the heavy
baryon mass from the SU(3) flavor breaking effect up to $O(p^3)$. Then we
extend the same formalism to calculate the chiral corrections to the axial
charges of the heavy baryons in the isospin symmetry limit.
| [
{
"created": "Fri, 21 Mar 2014 09:39:52 GMT",
"version": "v1"
},
{
"created": "Sun, 12 Oct 2014 09:51:04 GMT",
"version": "v2"
}
] | 2014-10-15 | [
[
"Jiang",
"Nan",
""
],
[
"Chen",
"Xiao-Lin",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] | We investigate the antitriplet and sextet heavy baryon systems with $J^P= \frac{1}{2}^+, \frac{3}{2}^+$ in the framework of the heavy baryon chiral perturbation theory. We first calculate the chiral corrections to the heavy baryon mass from the SU(3) flavor breaking effect up to $O(p^3)$. Then we extend the same formalism to calculate the chiral corrections to the axial charges of the heavy baryons in the isospin symmetry limit. |
0906.2584 | Xin-Bing Huang | Xin-Bing Huang | Massive Gauge Bosons in Yang-Mills Theory without Higgs Mechanism | 14 pages | null | null | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | Two kinds of Yang-Mills fields are found upon the concepts of mass eigenstate
and nonmass eigenstate. The Yang-Mills fields of the first kind were proposed
by Yang and Mills, which couple to the mass eigenstates with the same rest
mass, whose gauge bosons are massless. I find that there are second kind of
Yang-Mills fields, which are constructed on a five-dimensional manifold. Only
the nonmass eigenstates couple to the Yang-Mills fields of the second kind,
which are the nonmass eigenstates as well and composed of mass eigenstates of
gauge bosons. The mass eigenstates of the Yang-Mills fields of the second kind
live in the four-dimensional spacetime, the corresponding gauge bosons of which
may be massive. The SU(2)\times U(1) gauge fields of the second kind are
studied carefully, whose gauge bosons, which are the mass eigenstates, are the
W^{\pm}, Z^{0} and photon fields. The rest masses of W^{\pm} and Z^{0} obtained
are the same as that given by the Glashow-Salam-Weinberg model of electroweak
interactions. It is discussed that this model should be renormalizable.
| [
{
"created": "Mon, 15 Jun 2009 00:51:25 GMT",
"version": "v1"
}
] | 2009-06-16 | [
[
"Huang",
"Xin-Bing",
""
]
] | Two kinds of Yang-Mills fields are found upon the concepts of mass eigenstate and nonmass eigenstate. The Yang-Mills fields of the first kind were proposed by Yang and Mills, which couple to the mass eigenstates with the same rest mass, whose gauge bosons are massless. I find that there are second kind of Yang-Mills fields, which are constructed on a five-dimensional manifold. Only the nonmass eigenstates couple to the Yang-Mills fields of the second kind, which are the nonmass eigenstates as well and composed of mass eigenstates of gauge bosons. The mass eigenstates of the Yang-Mills fields of the second kind live in the four-dimensional spacetime, the corresponding gauge bosons of which may be massive. The SU(2)\times U(1) gauge fields of the second kind are studied carefully, whose gauge bosons, which are the mass eigenstates, are the W^{\pm}, Z^{0} and photon fields. The rest masses of W^{\pm} and Z^{0} obtained are the same as that given by the Glashow-Salam-Weinberg model of electroweak interactions. It is discussed that this model should be renormalizable. |
1807.11507 | Geraldine Servant | Geraldine Servant | The Serendipity of Electroweak Baryogenesis | ArXiv version of the contribution to the "Higgs cosmology" issue
published in Philosophical Transactions A, associated with the Theo Murphy
meeting which took place at the Royal Society Kavli Centre at Chicheley Hall
on March 27-28 2017. 12 pages, 6 figures | Phil.Trans.Roy.Soc.Lond. A376 (2018) no.2114, 20170124 | 10.1098/rsta.2017.0124 | DESY 18-131 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The origin of the matter antimatter asymmetry of the universe remains
unexplained in the Standard Model of particle physics. The origin of the
flavour structure is another major puzzle of the theory. In this article, we
report on recent work attempting to link the two themes through the appealing
framework of electroweak baryogenesis. We show that Yukawa couplings of
Standard Model fermions can be the source of CP-violation for electroweak
baryogenesis if they vary at the same time as the Higgs is acquiring its vacuum
expectation value, offering new avenues for electroweak baryogenesis. The
advantage of this approach is that it circumvents the usual severe bounds from
Electric Dipole moments. These ideas apply if the mechanism explaining the
flavour structure of the Standard Model is connected to electroweak symmetry
breaking, as motivated for instance in Randall-Sundrum or Composite Higgs
models. We compute the resulting baryon asymmetry for different configurations
of the Yukawa coupling variation across the bubble wall, and show that it can
naturally be of the right order.
| [
{
"created": "Mon, 30 Jul 2018 18:03:27 GMT",
"version": "v1"
}
] | 2018-08-08 | [
[
"Servant",
"Geraldine",
""
]
] | The origin of the matter antimatter asymmetry of the universe remains unexplained in the Standard Model of particle physics. The origin of the flavour structure is another major puzzle of the theory. In this article, we report on recent work attempting to link the two themes through the appealing framework of electroweak baryogenesis. We show that Yukawa couplings of Standard Model fermions can be the source of CP-violation for electroweak baryogenesis if they vary at the same time as the Higgs is acquiring its vacuum expectation value, offering new avenues for electroweak baryogenesis. The advantage of this approach is that it circumvents the usual severe bounds from Electric Dipole moments. These ideas apply if the mechanism explaining the flavour structure of the Standard Model is connected to electroweak symmetry breaking, as motivated for instance in Randall-Sundrum or Composite Higgs models. We compute the resulting baryon asymmetry for different configurations of the Yukawa coupling variation across the bubble wall, and show that it can naturally be of the right order. |
2203.09522 | Gil Peled | Gil Peled, Tomer Volansky | Constraining Dark Matter Inside Stars Using Spectroscopic Binaries and a
Modified Mass-Luminosity Relation | 7 pages, 2 figures; appendix: 10 pages, 2 figures | null | null | null | hep-ph astro-ph.SR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The presence of a dissipative dark matter (DM) sector may allow for the
trapping of a significant DM mass inside stars, either during structure
formation or by accretion over their lifetime, influencing stellar behavior
well into the Main Sequence stage. Motivated by this scenario, we place an
upper bound on the fractional DM mass within current-day Main Sequence stars.
Using double-lined spectroscopic binaries (SB2 stars), gravitational masses are
extracted and contrasted with luminous masses, derived using a modified
mass-luminosity relation which accounts for the effect of DM. High-accuracy
mass and luminosity data from a sample of 486 binary stars in the $0.18 <
M/M_\odot < 31$ mass range are partitioned into appropriate mass domains and
analyzed. A 95% C.L. upper limit of sub-5% is found for the subset of 263 stars
in the $1 < M/M_\odot < 2.4$ regime.
| [
{
"created": "Thu, 17 Mar 2022 18:00:00 GMT",
"version": "v1"
}
] | 2022-03-21 | [
[
"Peled",
"Gil",
""
],
[
"Volansky",
"Tomer",
""
]
] | The presence of a dissipative dark matter (DM) sector may allow for the trapping of a significant DM mass inside stars, either during structure formation or by accretion over their lifetime, influencing stellar behavior well into the Main Sequence stage. Motivated by this scenario, we place an upper bound on the fractional DM mass within current-day Main Sequence stars. Using double-lined spectroscopic binaries (SB2 stars), gravitational masses are extracted and contrasted with luminous masses, derived using a modified mass-luminosity relation which accounts for the effect of DM. High-accuracy mass and luminosity data from a sample of 486 binary stars in the $0.18 < M/M_\odot < 31$ mass range are partitioned into appropriate mass domains and analyzed. A 95% C.L. upper limit of sub-5% is found for the subset of 263 stars in the $1 < M/M_\odot < 2.4$ regime. |
1504.00505 | Fei Wang | Fei Wang, Wenyu Wang, Jin Min Yang | Reconcile muon g-2 anomaly with LHC data in SUGRA with generalized
gravity mediation | 14 pages, 7 figures; minor changes; references added; version
accepted by JHEP | JHEP 1506 (2015) 079 | 10.1007/JHEP06(2015)079 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | From generalized gravity mediation we build a SUGRA scenario in which the
gluino is much heavier than the electroweak gauginos at the GUT scale. We find
that such a non-universal gaugino scenario with very heavy gluino at the GUT
scale can be naturally obtained with proper high dimensional operators in the
framework of SU(5) GUT. Then, due to the effects of heavy gluino, at the weak
scale all colored sparticles are heavy while the uncolored sparticles are
light, which can explain the Brookhaven muon g-2 measurement while satisfying
the collider constraints (both the 125 GeV Higgs mass and the direct search
limits of sparticles) and dark matter requirements. We also find that, in order
to explain the muon g-2 measurement, the neutralino dark matter is lighter than
200 GeV in our scenario, which can be mostly covered by the future Xenon1T
experiment.
| [
{
"created": "Thu, 2 Apr 2015 10:29:17 GMT",
"version": "v1"
},
{
"created": "Fri, 29 May 2015 14:55:53 GMT",
"version": "v2"
}
] | 2015-06-24 | [
[
"Wang",
"Fei",
""
],
[
"Wang",
"Wenyu",
""
],
[
"Yang",
"Jin Min",
""
]
] | From generalized gravity mediation we build a SUGRA scenario in which the gluino is much heavier than the electroweak gauginos at the GUT scale. We find that such a non-universal gaugino scenario with very heavy gluino at the GUT scale can be naturally obtained with proper high dimensional operators in the framework of SU(5) GUT. Then, due to the effects of heavy gluino, at the weak scale all colored sparticles are heavy while the uncolored sparticles are light, which can explain the Brookhaven muon g-2 measurement while satisfying the collider constraints (both the 125 GeV Higgs mass and the direct search limits of sparticles) and dark matter requirements. We also find that, in order to explain the muon g-2 measurement, the neutralino dark matter is lighter than 200 GeV in our scenario, which can be mostly covered by the future Xenon1T experiment. |
hep-ph/0412065 | Mikhail Tokarev V. | J.V.Ilic (1), G.P.Skoro (2), M.V.Tokarev (3) | Jet Energy Density in Hadron-Hadron Collisions at High Energies | 11 pages, LaTeX, 8 figures, Presented at the XVII International
Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics
& Quantum Chromodynamics", Dubna, Russia, September 27 - October 2, 2004 | null | 10.1134/S154747710602004X | null | hep-ph | null | The average particle multiplicity density dN/deta is the dynamical quantity
which reflects some regularities of particle production in low-pT range. The
quantity is an important ingredient of z-scaling. Experimental results on
charged particle density are available for pp, pA and AA collisions while
experimental properties of the jet density are still an open question. The goal
of this work is to find the variable which will reflect the main features of
the jet production in low transverse energy range and play the role of the
scale factor for the scaling function psi(z) and variable z in data
z-presentation. The appropriate candidate is the variable we called "scaled jet
energy density". Scaled jet energy density is the probability to have a jet
with defined ET in defined xT and pseudorapidity regions. The PYTHIA6.2 Monte
Carlo generator is used for calculation of scaled jet energy density in
proton-proton collisions over a high energy range (sqrt s = 200-14000 GeV) and
at eta = 0. The properties of the new variable are discussed and sensitivity to
"physical scenarios" applied in the standard Monte Carlo generator is noted.
The results of scaled jet energy density at LHC energies are presented and
compared with predictions based on z-scaling.
| [
{
"created": "Sun, 5 Dec 2004 10:49:02 GMT",
"version": "v1"
}
] | 2018-10-31 | [
[
"Ilic",
"J. V.",
""
],
[
"Skoro",
"G. P.",
""
],
[
"Tokarev",
"M. V.",
""
]
] | The average particle multiplicity density dN/deta is the dynamical quantity which reflects some regularities of particle production in low-pT range. The quantity is an important ingredient of z-scaling. Experimental results on charged particle density are available for pp, pA and AA collisions while experimental properties of the jet density are still an open question. The goal of this work is to find the variable which will reflect the main features of the jet production in low transverse energy range and play the role of the scale factor for the scaling function psi(z) and variable z in data z-presentation. The appropriate candidate is the variable we called "scaled jet energy density". Scaled jet energy density is the probability to have a jet with defined ET in defined xT and pseudorapidity regions. The PYTHIA6.2 Monte Carlo generator is used for calculation of scaled jet energy density in proton-proton collisions over a high energy range (sqrt s = 200-14000 GeV) and at eta = 0. The properties of the new variable are discussed and sensitivity to "physical scenarios" applied in the standard Monte Carlo generator is noted. The results of scaled jet energy density at LHC energies are presented and compared with predictions based on z-scaling. |
hep-ph/9609477 | Maria Krawczyk | Maria Krawczyk (Institute of Theoretical Physics, University of
Warsaw) | Higgs Search at HERA | 12 pages, including 5 figure; Contribution to "Future Physics at
HERA" Workshop, 1995-1996, Hamburg, DESY | null | null | IFT 21/96 | hep-ph | null | Present data do not rule out a light neutral Higgs particle with mass below
40--50 GeV in the framework of 2HDM with $ tan \beta \sim $ 20-30. The
promising possibility of searching for a light Higgs particle in such a
scenario in photoproduction at HERA collider is discussed. For the MSSM there
is only a very small chance to observe the Higgs sector, and only for limited
mass range $\sim$ 45-50 GeV and with large $ tan \beta$.
| [
{
"created": "Wed, 25 Sep 1996 19:19:39 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Krawczyk",
"Maria",
"",
"Institute of Theoretical Physics, University of\n Warsaw"
]
] | Present data do not rule out a light neutral Higgs particle with mass below 40--50 GeV in the framework of 2HDM with $ tan \beta \sim $ 20-30. The promising possibility of searching for a light Higgs particle in such a scenario in photoproduction at HERA collider is discussed. For the MSSM there is only a very small chance to observe the Higgs sector, and only for limited mass range $\sim$ 45-50 GeV and with large $ tan \beta$. |
hep-ph/9302314 | Jutta Kunz | Sylvie Braibant, Yves Brihaye and Jutta Kunz | Sphalerons at finite temperature | 14 pages, plain tex, 5 figures appended as postscript files at the
end of the paper. MONS-93/01, THU-93/01 | Int.J.Mod.Phys. A8 (1993) 5563-5574 | 10.1142/S0217751X93002198 | null | hep-ph | null | We construct the sphaleron for several temperature dependent effective
potentials. We determine the sphaleron energy as a function of temperature and
demonstrate that the sphaleron energy at a given temperature $T$ is well
approximated by the sphaleron energy at temperature zero scaled by the ratio of
the vacuum expectation values of the Higgs field at temperatures $T$ and zero.
We address the cosmological upper bound on the Higgs mass.
| [
{
"created": "Fri, 26 Feb 1993 15:27:33 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Braibant",
"Sylvie",
""
],
[
"Brihaye",
"Yves",
""
],
[
"Kunz",
"Jutta",
""
]
] | We construct the sphaleron for several temperature dependent effective potentials. We determine the sphaleron energy as a function of temperature and demonstrate that the sphaleron energy at a given temperature $T$ is well approximated by the sphaleron energy at temperature zero scaled by the ratio of the vacuum expectation values of the Higgs field at temperatures $T$ and zero. We address the cosmological upper bound on the Higgs mass. |
2402.02703 | Jun He Prof. | Shu-Yi Kong, Jun-Tao Zhu, Shu Chen, Jun He | Production of open-charm pentaquark molecules in decay $B^0 \rightarrow
\bar{D}^0 p \bar{p}$ | 8 pages, 3 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This study explores the production of open-charm pentaquark molecular states,
specifically $N\bar{D}^*$ and $\bar{N}\bar{D}^*$, within the $B^0 \rightarrow
\bar{D}^0 p \bar{p}$ decay process. We analyze the invariant mass spectrum of
$p\bar{D}^0$ and $\bar{p}\bar{D}^0$, incorporating the rescattering process
calculated using a quasipotential Bethe-Salpeter equation approach. Our
findings suggest the potential identification of the isoscalar
$\bar{N}\bar{D}^*$ molecule with $3/2^+$, serving as the antiparticle partner
of the $\Lambda_c(2940)$, in the $\bar{p}\bar{D}^0$ mass distribution.
Additionally, distinctive signals of the isovector $N\bar{D}^*$ molecule with
$1/2^-$ may emerge in the $p\bar{D}^0$ invariant mass distribution. We
highlight the significance of the three-body decay of the bottom meson as a
valuable avenue for studying open-charm molecules and advocate for increased
attention and more precise experimental measurements of the $B^0 \rightarrow
\bar{D}^0 p \bar{p}$ process.
| [
{
"created": "Mon, 5 Feb 2024 03:32:27 GMT",
"version": "v1"
}
] | 2024-02-06 | [
[
"Kong",
"Shu-Yi",
""
],
[
"Zhu",
"Jun-Tao",
""
],
[
"Chen",
"Shu",
""
],
[
"He",
"Jun",
""
]
] | This study explores the production of open-charm pentaquark molecular states, specifically $N\bar{D}^*$ and $\bar{N}\bar{D}^*$, within the $B^0 \rightarrow \bar{D}^0 p \bar{p}$ decay process. We analyze the invariant mass spectrum of $p\bar{D}^0$ and $\bar{p}\bar{D}^0$, incorporating the rescattering process calculated using a quasipotential Bethe-Salpeter equation approach. Our findings suggest the potential identification of the isoscalar $\bar{N}\bar{D}^*$ molecule with $3/2^+$, serving as the antiparticle partner of the $\Lambda_c(2940)$, in the $\bar{p}\bar{D}^0$ mass distribution. Additionally, distinctive signals of the isovector $N\bar{D}^*$ molecule with $1/2^-$ may emerge in the $p\bar{D}^0$ invariant mass distribution. We highlight the significance of the three-body decay of the bottom meson as a valuable avenue for studying open-charm molecules and advocate for increased attention and more precise experimental measurements of the $B^0 \rightarrow \bar{D}^0 p \bar{p}$ process. |
1410.2616 | Pierre-Hugues Beauchemin | P-H. Beauchemin, V.A. Bednyakov, G.I. Lykasov, Yu.Yu. Stepanenko | Search for intrinsic charm in vector boson production accompanied by
heavy flavor jets | 14 pages, 11 figures | Phys. Rev. D 92, 034014 (2015) | 10.1103/PhysRevD.92.034014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Up to now, the existence of intrinsic (or valence-like) heavy quark component
of the proton distribution functions has not yet been confirmed or rejected.
The LHC with pp-collisions at $\sqrt{s}$ = 7-13 TeV can supply us with extra
unique information concerning this hypothesis. On the basis of our theoretical
studies, it is demonstrated that investigations of the intrinsic heavy quark
contributions look very promising in processes like $pp \rightarrow Z/W + c(b)
+ X$. A ratio of $Z+$ heavy jets over $W+$ heavy jets differential cross
section as a function of the leading jet transverse momentum is proposed to
maximize the sensitivity to the intrinsic charm component of the proton.
| [
{
"created": "Thu, 9 Oct 2014 20:36:41 GMT",
"version": "v1"
}
] | 2015-08-19 | [
[
"Beauchemin",
"P-H.",
""
],
[
"Bednyakov",
"V. A.",
""
],
[
"Lykasov",
"G. I.",
""
],
[
"Stepanenko",
"Yu. Yu.",
""
]
] | Up to now, the existence of intrinsic (or valence-like) heavy quark component of the proton distribution functions has not yet been confirmed or rejected. The LHC with pp-collisions at $\sqrt{s}$ = 7-13 TeV can supply us with extra unique information concerning this hypothesis. On the basis of our theoretical studies, it is demonstrated that investigations of the intrinsic heavy quark contributions look very promising in processes like $pp \rightarrow Z/W + c(b) + X$. A ratio of $Z+$ heavy jets over $W+$ heavy jets differential cross section as a function of the leading jet transverse momentum is proposed to maximize the sensitivity to the intrinsic charm component of the proton. |
hep-ph/0410223 | Riccardo Barbieri | Riccardo Barbieri | Searching for new physics at future accelerators | 9 pages, plenary talk at ICHEP2004, Beijing, August 2004, typos
corrected, added references | Int.J.Mod.Phys. A20 (2005) 5184-5192 | 10.1142/S0217751X05028697 | null | hep-ph | null | I overview the status of the Electroweak Symmetry Breaking problem, paying
special attention to the possible signals of new physics at the Large Hadron
Collider (and at a Linear Collider)
| [
{
"created": "Fri, 15 Oct 2004 08:25:38 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Oct 2004 09:56:28 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Barbieri",
"Riccardo",
""
]
] | I overview the status of the Electroweak Symmetry Breaking problem, paying special attention to the possible signals of new physics at the Large Hadron Collider (and at a Linear Collider) |
hep-ph/9301247 | null | E.Kh. Akhmedov, S.T. Petcov and A.Yu. Smirnov | Pontecorvo's Original Oscillations Revisited | LaTeX, 14 pages, 1 figure (not included but available upon request by
fax or ordinary mail), SISSA 9/93/EP, IC/93/10 | Phys.Lett.B309:95-102,1993 | 10.1016/0370-2693(93)91510-T | null | hep-ph | null | We show that a left-handed neutrino $\nu_L$ can oscillate into its $CP$-
conjugated state $\bar{\nu}_R$ with maximal amplitude, in direct analogy with
$K^0-\bar{K}^0$ oscillations. Peculiarities of such oscillations under
different conditions are studied.
| [
{
"created": "Mon, 18 Jan 1993 11:08:01 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Akhmedov",
"E. Kh.",
""
],
[
"Petcov",
"S. T.",
""
],
[
"Smirnov",
"A. Yu.",
""
]
] | We show that a left-handed neutrino $\nu_L$ can oscillate into its $CP$- conjugated state $\bar{\nu}_R$ with maximal amplitude, in direct analogy with $K^0-\bar{K}^0$ oscillations. Peculiarities of such oscillations under different conditions are studied. |
1112.4937 | Eberhard Klempt | A. V. Anisovich, R. Beck, E. Klempt, V. A. Nikonov, A. V. Sarantsev,
and U. Thoma | Properties of baryon resonances from a multichannel partial wave
analysis | 12 pages, 8 Tables | null | 10.1140/epja/i2012-12015-8 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Properties of nucleon and $\Delta$ resonances are derived from a multichannel
partial wave analysis. The statistical significance of pion and photo-induced
inelastic reactions off protons are studied in a multichannel partial-wave
analysis.
| [
{
"created": "Wed, 21 Dec 2011 07:37:32 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Anisovich",
"A. V.",
""
],
[
"Beck",
"R.",
""
],
[
"Klempt",
"E.",
""
],
[
"Nikonov",
"V. A.",
""
],
[
"Sarantsev",
"A. V.",
""
],
[
"Thoma",
"U.",
""
]
] | Properties of nucleon and $\Delta$ resonances are derived from a multichannel partial wave analysis. The statistical significance of pion and photo-induced inelastic reactions off protons are studied in a multichannel partial-wave analysis. |
1006.1448 | Cai-Dian Lu | Cai-Dian Lu and Wei Wang | Study light scalar meson property from heavy meson decays | 5 pages, talk given at 45th Rencontres de Moriond QCD and High Energy
Interactions, March 2010, La Thuile and XIII International Conference on
Hadron Spectroscopy, Florida, 2009 | AIP Conf.Proc.1257:257-261,2010 | 10.1063/1.3483328 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the SU(3) symmetry limit, the ratio $R\equiv\frac{{\cal B}(D^+\to
f_0l^+\nu)+ {\cal B}(D^+\to \sigma l^+\nu)}{{\cal B}(D^+\to a_0^0l^+\nu)}$ is
equal to 1 if the scalar mesons are $\bar qq$ states, while it is 3 if these
mesons are tentraquark states. This ratio provides a model-independent way to
distinguish the descriptions for light scalar mesons . It also applies to the
$B^-\to Sl^-\bar\nu$ and $\bar B^0\to J/\psi(\eta_c) S$ decays. The SU(3)
symmetry breaking effect is found to be under control, which will not spoil our
method. The branching fractions of the $D^+\to S l^+\nu$, $B^-\to S l^-\bar\nu$
and $\bar B^0\to J/\psi(\eta_c) S$ decays roughly have the order $10^{-4}$,
$10^{-5}$ and $10^{-6}$, respectively. The B factory experiments and ongoing
BEPC-II experiments are able to measure these channels and accordingly to
provide the detailed information of the scalar meson inner structure.
| [
{
"created": "Tue, 8 Jun 2010 04:14:34 GMT",
"version": "v1"
}
] | 2014-11-21 | [
[
"Lu",
"Cai-Dian",
""
],
[
"Wang",
"Wei",
""
]
] | In the SU(3) symmetry limit, the ratio $R\equiv\frac{{\cal B}(D^+\to f_0l^+\nu)+ {\cal B}(D^+\to \sigma l^+\nu)}{{\cal B}(D^+\to a_0^0l^+\nu)}$ is equal to 1 if the scalar mesons are $\bar qq$ states, while it is 3 if these mesons are tentraquark states. This ratio provides a model-independent way to distinguish the descriptions for light scalar mesons . It also applies to the $B^-\to Sl^-\bar\nu$ and $\bar B^0\to J/\psi(\eta_c) S$ decays. The SU(3) symmetry breaking effect is found to be under control, which will not spoil our method. The branching fractions of the $D^+\to S l^+\nu$, $B^-\to S l^-\bar\nu$ and $\bar B^0\to J/\psi(\eta_c) S$ decays roughly have the order $10^{-4}$, $10^{-5}$ and $10^{-6}$, respectively. The B factory experiments and ongoing BEPC-II experiments are able to measure these channels and accordingly to provide the detailed information of the scalar meson inner structure. |
1605.07357 | Fabio Siringo | Fabio Siringo | Analytic structure of QCD propagators in Minkowski space | Some comments on BRST invariance and some new references are added in
the new version | Phys. Rev. D 94, 114036 (2016) | 10.1103/PhysRevD.94.114036 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Analytical functions for the propagators of QCD, including a set of chiral
quarks, are derived by a one-loop massive expansion in the Landau gauge, deep
in the infrared. By analytic continuation, the spectral functions are studied
in Minkowski space, yielding a direct proof of positivity violation and
confinement from first principles.The dynamical breaking of chiral symmetry is
described on the same footing of gluon mass generation, providing a unified
picture. While dealing with the exact Lagrangian, the expansion is based on
massive free-particle propagators, is safe in the infrared and is equivalent to
the standard perturbation theory in the UV. By dimensional regularization, all
diverging mass terms cancel exactly without including mass counterterms that
would spoil the gauge and chiral symmetry of the Lagrangian. Universal scaling
properties are predicted for the inverse dressing functions and shown to be
satisfied by the lattice data. Complex conjugated poles are found for the gluon
propagator, in agreement with the i-particle scenario.
| [
{
"created": "Tue, 24 May 2016 10:11:40 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Oct 2016 19:00:57 GMT",
"version": "v2"
},
{
"created": "Sun, 1 Jan 2017 18:54:20 GMT",
"version": "v3"
}
] | 2017-01-04 | [
[
"Siringo",
"Fabio",
""
]
] | Analytical functions for the propagators of QCD, including a set of chiral quarks, are derived by a one-loop massive expansion in the Landau gauge, deep in the infrared. By analytic continuation, the spectral functions are studied in Minkowski space, yielding a direct proof of positivity violation and confinement from first principles.The dynamical breaking of chiral symmetry is described on the same footing of gluon mass generation, providing a unified picture. While dealing with the exact Lagrangian, the expansion is based on massive free-particle propagators, is safe in the infrared and is equivalent to the standard perturbation theory in the UV. By dimensional regularization, all diverging mass terms cancel exactly without including mass counterterms that would spoil the gauge and chiral symmetry of the Lagrangian. Universal scaling properties are predicted for the inverse dressing functions and shown to be satisfied by the lattice data. Complex conjugated poles are found for the gluon propagator, in agreement with the i-particle scenario. |
1807.04120 | Tyler Gorda | Tyler Gorda, Aleksi Kurkela, Paul Romatschke, Saga S\"appi, and Aleksi
Vuorinen | NNNLO pressure of cold quark matter: leading logarithm | 8 pages with appendix, 2 figures; v3: Added footnote to point out
minus sign error in final result | Phys. Rev. Lett. 121, 202701 (2018) | 10.1103/PhysRevLett.121.202701 | CERN-TH-2018-230, HIP-2018-13/TH | hep-ph astro-ph.HE nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | At high baryon chemical potential $\mu_B$, the equation of state of QCD
allows a weak-coupling expansion in the QCD coupling $\alpha_s$. The result is
currently known up to and including the full next-to-next-to-leading order
(NNLO) $\alpha_s^2$. Starting at this order, the computations are complicated
by the modification of particle propagation in a dense medium, which
necessitates non-perturbative treatment of the scale $\alpha_s^{1/2} \mu_B$. In
this work, we apply a Hard-Thermal-Loop scheme for capturing the contributions
of this scale to the weak-coupling expansion, and use it to determine the
leading-logarithm contribution to NNNLO: $\alpha_s^3 \ln^2 \alpha_s$. This
result is the first improvement to the equation of state of massless cold quark
matter in 40 years. The new term is negligibly small, and thus significantly
increases our confidence in the applicability of the weak-coupling expansion.
| [
{
"created": "Wed, 11 Jul 2018 13:35:45 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Oct 2018 13:59:20 GMT",
"version": "v2"
},
{
"created": "Fri, 19 Apr 2024 15:58:38 GMT",
"version": "v3"
}
] | 2024-04-22 | [
[
"Gorda",
"Tyler",
""
],
[
"Kurkela",
"Aleksi",
""
],
[
"Romatschke",
"Paul",
""
],
[
"Säppi",
"Saga",
""
],
[
"Vuorinen",
"Aleksi",
""
]
] | At high baryon chemical potential $\mu_B$, the equation of state of QCD allows a weak-coupling expansion in the QCD coupling $\alpha_s$. The result is currently known up to and including the full next-to-next-to-leading order (NNLO) $\alpha_s^2$. Starting at this order, the computations are complicated by the modification of particle propagation in a dense medium, which necessitates non-perturbative treatment of the scale $\alpha_s^{1/2} \mu_B$. In this work, we apply a Hard-Thermal-Loop scheme for capturing the contributions of this scale to the weak-coupling expansion, and use it to determine the leading-logarithm contribution to NNNLO: $\alpha_s^3 \ln^2 \alpha_s$. This result is the first improvement to the equation of state of massless cold quark matter in 40 years. The new term is negligibly small, and thus significantly increases our confidence in the applicability of the weak-coupling expansion. |
hep-ph/0402050 | Hiroaki Abuki | Hiroaki Abuki | Role of Strange Quark Mass in Pairing Phenomena in QCD | 10 pages, talk at the KIAS-APCTP International Symposium on
Astro-Hadron Physics "Compact Stars: Quest for New States of Dense Matter" | null | 10.1142/9789812702524_0011 | YITP-04-09 | hep-ph | null | We study the dynamical effect of strange quark mass as well as kinematical
one on the color-flavor unlocking transition using a NJL model. Paying a
special attention to the multiplicity of gap parameters, we derive an exact
formula of the effective potential for 5-gap parameters. Based on this, we
discuss that the unlocking transition might be of second order rather than of
first order as is predicted by a simple kinematical criterion for the
unlocking.
| [
{
"created": "Thu, 5 Feb 2004 18:27:36 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Abuki",
"Hiroaki",
""
]
] | We study the dynamical effect of strange quark mass as well as kinematical one on the color-flavor unlocking transition using a NJL model. Paying a special attention to the multiplicity of gap parameters, we derive an exact formula of the effective potential for 5-gap parameters. Based on this, we discuss that the unlocking transition might be of second order rather than of first order as is predicted by a simple kinematical criterion for the unlocking. |
0912.5138 | Hua-Xing Chen | Hua-Xing Chen, Atsushi Hosaka, Hiroshi Toki, and Shi-Lin Zhu | Light Scalar Meson sigma(600) in QCD Sum Rule with Continuum | 9 pages, 7 figures, comments and suggestions welcome | Phys.Rev.D81:114034,2010 | 10.1103/PhysRevD.81.114034 | null | hep-ph | http://creativecommons.org/licenses/publicdomain/ | The light scalar meson sigma(600) is known to appear at low excitation energy
with very large width on top of continuum states. We investigate it in the QCD
sum rule as an example of resonance structures appearing above the
corresponding thresholds. We use all the possible local tetraquark currents by
taking linear combinations of five independent local ones. We ought to consider
the pi-pi continuum contribution in the phenomenological side of the QCD sum
rule in order to obtain a good sum rule signal. We study the stability of the
extracted mass against the Borel mass and the threshold value and find the
sigma(600) mass at 530 MeV +- 40 MeV. In addition we find the extracted mass
has an increasing tendency with the Borel mass, which is interpreted as caused
by the width of the resonance.
| [
{
"created": "Mon, 28 Dec 2009 07:35:40 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Jun 2010 04:33:46 GMT",
"version": "v2"
}
] | 2010-06-25 | [
[
"Chen",
"Hua-Xing",
""
],
[
"Hosaka",
"Atsushi",
""
],
[
"Toki",
"Hiroshi",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] | The light scalar meson sigma(600) is known to appear at low excitation energy with very large width on top of continuum states. We investigate it in the QCD sum rule as an example of resonance structures appearing above the corresponding thresholds. We use all the possible local tetraquark currents by taking linear combinations of five independent local ones. We ought to consider the pi-pi continuum contribution in the phenomenological side of the QCD sum rule in order to obtain a good sum rule signal. We study the stability of the extracted mass against the Borel mass and the threshold value and find the sigma(600) mass at 530 MeV +- 40 MeV. In addition we find the extracted mass has an increasing tendency with the Borel mass, which is interpreted as caused by the width of the resonance. |
2406.17853 | Alessandro Lella | Alessandro Lella, Francesca Calore, Pierluca Carenza, Alessandro
Mirizzi | Constraining gravitational-wave backgrounds from conversions into
photons in the Galactic magnetic field | 14 pages, 6 figures | null | null | LAPTH-036/24 | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | High-frequency gravitational waves ($f \gtrsim 1$ MHz) may provide a unique
signature for the existence of exotic physics. The lack of current and future
gravitational-wave experiments sensitive at those frequencies leads to the need
of employing different indirect techniques. Notably, one of the most promising
one is constituted by graviton-photon conversions in magnetic fields. In this
work, we focus on conversions of a gravitational-wave background into photons
inside the Milky-Way magnetic field, taking into account the state-of-the-art
models for both regular and turbulent components. We discuss how
graviton-to-photon conversions may lead to imprints in the cosmic photon
background spectrum in the range of frequencies $f\sim10^{9}-10^{26}\,$Hz,
where the observed photon flux is widely explained by astrophysics emission
models. Hence, the absence of any significant evidence for a diffuse photon
flux induced by graviton-photon conversions allows us to set stringent
constraints on the gravitational-wave strain $h_c$, strengthening current
astrophysical bounds by $\sim1-2$ orders of magnitude in the whole range of
frequencies considered.
| [
{
"created": "Tue, 25 Jun 2024 18:00:02 GMT",
"version": "v1"
}
] | 2024-06-27 | [
[
"Lella",
"Alessandro",
""
],
[
"Calore",
"Francesca",
""
],
[
"Carenza",
"Pierluca",
""
],
[
"Mirizzi",
"Alessandro",
""
]
] | High-frequency gravitational waves ($f \gtrsim 1$ MHz) may provide a unique signature for the existence of exotic physics. The lack of current and future gravitational-wave experiments sensitive at those frequencies leads to the need of employing different indirect techniques. Notably, one of the most promising one is constituted by graviton-photon conversions in magnetic fields. In this work, we focus on conversions of a gravitational-wave background into photons inside the Milky-Way magnetic field, taking into account the state-of-the-art models for both regular and turbulent components. We discuss how graviton-to-photon conversions may lead to imprints in the cosmic photon background spectrum in the range of frequencies $f\sim10^{9}-10^{26}\,$Hz, where the observed photon flux is widely explained by astrophysics emission models. Hence, the absence of any significant evidence for a diffuse photon flux induced by graviton-photon conversions allows us to set stringent constraints on the gravitational-wave strain $h_c$, strengthening current astrophysical bounds by $\sim1-2$ orders of magnitude in the whole range of frequencies considered. |
2008.12554 | Fu-Hu Liu | Yang-Ming Tai, Pei-Pin Yang, Fu-Hu Liu | An analysis of transverse momentum spectra of various jets produced in
high energy collisions | 18 pages, 11 figures. Advances in High Energy Physics, accepted | Advances in High Energy Physics 2021, 8832892 (2021) (16 pages) | 10.1155/2021/8832892 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | With the framework of the multi-source thermal model, we analyze the
experimental transverse momentum spectra of various jets produced in different
collisions at high energies. Two energy sources, a projectile participant quark
and a target participant quark, are considered. Each energy source (each
participant quark) is assumed to contribute to the transverse momentum
distribution to be the TP-like function, i.e. a revised Tsallis--Pareto-type
function. The contribution of the two participant quarks to the transverse
momentum distribution is then the convolution of two TP-like functions. The
model distribution can be used to fit the experimental spectra measured by
different collaborations. The related parameters such as the entropy
index-related, effective temperature, and revised index are then obtained. The
trends of these parameters are useful to understand the characteristic of high
energy collisions.
| [
{
"created": "Fri, 28 Aug 2020 09:41:30 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Nov 2020 12:59:34 GMT",
"version": "v2"
}
] | 2021-01-14 | [
[
"Tai",
"Yang-Ming",
""
],
[
"Yang",
"Pei-Pin",
""
],
[
"Liu",
"Fu-Hu",
""
]
] | With the framework of the multi-source thermal model, we analyze the experimental transverse momentum spectra of various jets produced in different collisions at high energies. Two energy sources, a projectile participant quark and a target participant quark, are considered. Each energy source (each participant quark) is assumed to contribute to the transverse momentum distribution to be the TP-like function, i.e. a revised Tsallis--Pareto-type function. The contribution of the two participant quarks to the transverse momentum distribution is then the convolution of two TP-like functions. The model distribution can be used to fit the experimental spectra measured by different collaborations. The related parameters such as the entropy index-related, effective temperature, and revised index are then obtained. The trends of these parameters are useful to understand the characteristic of high energy collisions. |
2206.01577 | Michael Trott | Michael Trott | The geometric SMEFT | 7 pages (Extended version of MoriondEW 2022 contribution) | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Effective field theories, like the Standard Model Effective Field Theory
(SMEFT), are defined by a chosen field content and a set of symmetries, up to a
cut off scale $\Lambda$. Usually, in order to perform calculations, gauge
independent field re-definitions consistent with the symmetries of the theory
are then used to redefine the fields. This procedure results in a fixed
(non-redundant) operator basis, that is not itself field re-definition
invariant. Recently, an alternative approach of identifying and calculating
with field space geometry has been developed. Field redefinition invariants,
characterising field space geometry, appear in observables in amplitude
perturbations, and have an expansion in terms of local operators. In the case
of the SMEFT, calculating via the geometric approach is known as the geoSMEFT.
This approach makes it much easier to calculate at high orders in $1/\Lambda$
in the SMEFT, and can directly result in a complete characterisation of an
amplitude perturbation in the $1/\Lambda$ expansion. Using the geoSMEFT,
several consistent and complete $\mathcal{O}(1/\Lambda^4)$ results are now
known. We define the geoSMEFT and demonstrate its use in some examples.
| [
{
"created": "Fri, 3 Jun 2022 13:59:08 GMT",
"version": "v1"
}
] | 2022-06-06 | [
[
"Trott",
"Michael",
""
]
] | Effective field theories, like the Standard Model Effective Field Theory (SMEFT), are defined by a chosen field content and a set of symmetries, up to a cut off scale $\Lambda$. Usually, in order to perform calculations, gauge independent field re-definitions consistent with the symmetries of the theory are then used to redefine the fields. This procedure results in a fixed (non-redundant) operator basis, that is not itself field re-definition invariant. Recently, an alternative approach of identifying and calculating with field space geometry has been developed. Field redefinition invariants, characterising field space geometry, appear in observables in amplitude perturbations, and have an expansion in terms of local operators. In the case of the SMEFT, calculating via the geometric approach is known as the geoSMEFT. This approach makes it much easier to calculate at high orders in $1/\Lambda$ in the SMEFT, and can directly result in a complete characterisation of an amplitude perturbation in the $1/\Lambda$ expansion. Using the geoSMEFT, several consistent and complete $\mathcal{O}(1/\Lambda^4)$ results are now known. We define the geoSMEFT and demonstrate its use in some examples. |
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