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hep-ph/0312306
Stefan Hesselbach
A. Bartl, H. Fraas, S. Hesselbach, K. Hidaka, T. Kernreiter, O. Kittel and W. Porod
Impact of CP phases on SUSY particle production and decays
10 pages, 8 eps figures, LaTeX, uses JHEP3.cls; talk given at the International Workshop on Astroparticle and High Energy Physics (AHEP), Valencia, Spain, 14-18 Oct. 2003
null
null
IFIC/03-59, TGU-33, UWThPh-2003-43, WUE-ITP-2003-026, ZU-TH 21/03
hep-ph
null
We report on the results of a phenomenological study of top squarks (stop_{1,2}) and bottom squarks (sbottom_{1,2}) in the Minimal Supersymmetric Standard Model (MSSM) with complex parameters A_t, A_b, mu and M_1. In particular we focus on the CP phase dependence of the branching ratios of stop_{1,2} and sbottom_{1,2} decays. We find that the effect of the phases on the stop_{1,2} and sbottom_{1,2} decays can be quite significant in a large region of the MSSM parameter space. We also study a CP asymmetry in sfermion decays.
[ { "created": "Sun, 21 Dec 2003 18:01:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bartl", "A.", "" ], [ "Fraas", "H.", "" ], [ "Hesselbach", "S.", "" ], [ "Hidaka", "K.", "" ], [ "Kernreiter", "T.", "" ], [ "Kittel", "O.", "" ], [ "Porod", "W.", "" ] ]
We report on the results of a phenomenological study of top squarks (stop_{1,2}) and bottom squarks (sbottom_{1,2}) in the Minimal Supersymmetric Standard Model (MSSM) with complex parameters A_t, A_b, mu and M_1. In particular we focus on the CP phase dependence of the branching ratios of stop_{1,2} and sbottom_{1,2} decays. We find that the effect of the phases on the stop_{1,2} and sbottom_{1,2} decays can be quite significant in a large region of the MSSM parameter space. We also study a CP asymmetry in sfermion decays.
hep-ph/0210101
Peschanski
J. Lamouroux (DEA, Grenoble University), R. Peschanski (Saclay, Th.), C. Royon and L. Schoeffel (Saclay, Exp.)
Hard diffraction and the nature of the Pomeron
14 pages, 9 figures
Nucl.Phys.B649:312-326,2003
10.1016/S0550-3213(02)01013-1
null
hep-ph
null
We ask the question whether the quark and gluon distributions in the Pomeron obtained from QCD fits to hard diffraction processes at HERA can be dynamically generated from a state made of ``valence-like'' gluons and sea quarks as input. By a method combining backward Q^2-evolution for data exploration and forward Q^2-evolution for a best fit determination, we find that the diffractive structure functions published by the H1 collaboration at HERA can be described by a simple ``valence-like'' input at an initial scale of order mu^2 ~ 2.3-2.7 GeV^2. The parton number sum rules at the initial scale mu^2 for the H1 fit gives 2.1\pm .1\pm .1 and .13\pm .01 \pm .02 for gluon and sea quarks respectively, corresponding to an initial Pomeron state made of (almost) only two gluons. It has flat gluon density leading to a plausible interpretation in terms of a gluonium state.
[ { "created": "Mon, 7 Oct 2002 13:22:44 GMT", "version": "v1" } ]
2008-11-26
[ [ "Lamouroux", "J.", "", "DEA, Grenoble University" ], [ "Peschanski", "R.", "", "Saclay, Th." ], [ "Royon", "C.", "", "Saclay, Exp." ], [ "Schoeffel", "L.", "", "Saclay, Exp." ] ]
We ask the question whether the quark and gluon distributions in the Pomeron obtained from QCD fits to hard diffraction processes at HERA can be dynamically generated from a state made of ``valence-like'' gluons and sea quarks as input. By a method combining backward Q^2-evolution for data exploration and forward Q^2-evolution for a best fit determination, we find that the diffractive structure functions published by the H1 collaboration at HERA can be described by a simple ``valence-like'' input at an initial scale of order mu^2 ~ 2.3-2.7 GeV^2. The parton number sum rules at the initial scale mu^2 for the H1 fit gives 2.1\pm .1\pm .1 and .13\pm .01 \pm .02 for gluon and sea quarks respectively, corresponding to an initial Pomeron state made of (almost) only two gluons. It has flat gluon density leading to a plausible interpretation in terms of a gluonium state.
2108.01607
Georg Wolschin
Georg Wolschin
Nonlinear diffusion of gluons
14 pages, 6 figures; as published in PHYSICA A
Physica A 597 (2022) 127299
10.1016/j.physa.2022.127299
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
It is proposed to consider the fast thermalization of gluons in relativistic heavy-ion collisions as a diffusion process in momentum space. Closed-form analytical solutions of a nonlinear boson diffusion equation (NBDE) with constant drift and diffusion coefficients v, D and boundary conditions at the singularity are derived. The time evolution towards local central temperatures T< 600 MeV through inelastic gluon scatterings in heavy-ion collisions is calculated for under- and overoccupied systems in the full momentum range. The results are consistent with QCD-based numerical calculations for gluon thermalization via inelastic gluon collisions.
[ { "created": "Tue, 3 Aug 2021 16:16:42 GMT", "version": "v1" }, { "created": "Thu, 31 Mar 2022 10:41:50 GMT", "version": "v2" } ]
2022-04-08
[ [ "Wolschin", "Georg", "" ] ]
It is proposed to consider the fast thermalization of gluons in relativistic heavy-ion collisions as a diffusion process in momentum space. Closed-form analytical solutions of a nonlinear boson diffusion equation (NBDE) with constant drift and diffusion coefficients v, D and boundary conditions at the singularity are derived. The time evolution towards local central temperatures T< 600 MeV through inelastic gluon scatterings in heavy-ion collisions is calculated for under- and overoccupied systems in the full momentum range. The results are consistent with QCD-based numerical calculations for gluon thermalization via inelastic gluon collisions.
hep-ph/0004124
Antonio Delgado
A. Delgado and M. Quiros
The lightest Higgs mass in supersymmetric models with extra dimensions
Latex2e, 11 pages, 1 figure
Phys.Lett.B484:355-361,2000
10.1016/S0370-2693(00)00650-X
LPTENS-00/18,IEM-FT-202/00,IFT-UAM/CSIC-00-17
hep-ph
null
In the four-dimensional supersymmetric standard model extended with gauge singlets the lightest Higgs boson mass, $M_H$, has an important contribution proportional to the squared of the superpotential coupling $\lambda$ of singlets to Higgs fields, $\lambda SH_1\cdot H_2$. The requirement of perturbativity up to the unification scale yields an upper bound on $M_H\sim 140$ GeV. In extensions to theories with (longitudinal) extra dimensions at the TeV where such coupling exists and massive Kaluza-Klein states fall into N=2 representations, if either of the Higgs or singlet fields live in the bulk of the extra dimensions, the $\beta$-function of $\lambda$ is suppressed due to the absence of anomalous dimension of hypermultiplets to leading order. This implies a slower running of $\lambda$ and an enhancement of its low energy value. The $M_H$ upper bound increases to values $M_H\lesssim 165$ GeV.
[ { "created": "Thu, 13 Apr 2000 18:28:52 GMT", "version": "v1" } ]
2008-11-26
[ [ "Delgado", "A.", "" ], [ "Quiros", "M.", "" ] ]
In the four-dimensional supersymmetric standard model extended with gauge singlets the lightest Higgs boson mass, $M_H$, has an important contribution proportional to the squared of the superpotential coupling $\lambda$ of singlets to Higgs fields, $\lambda SH_1\cdot H_2$. The requirement of perturbativity up to the unification scale yields an upper bound on $M_H\sim 140$ GeV. In extensions to theories with (longitudinal) extra dimensions at the TeV where such coupling exists and massive Kaluza-Klein states fall into N=2 representations, if either of the Higgs or singlet fields live in the bulk of the extra dimensions, the $\beta$-function of $\lambda$ is suppressed due to the absence of anomalous dimension of hypermultiplets to leading order. This implies a slower running of $\lambda$ and an enhancement of its low energy value. The $M_H$ upper bound increases to values $M_H\lesssim 165$ GeV.
1902.10256
Carlos E. Yaguna
Carlos E. Yaguna
New Constraints on Xenonphobic Dark Matter from DEAP-3600
10 pages. V2: matches published version
JCAP04(2019)041
10.1088/1475-7516/2019/04/041
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The first-year results from DEAP-3600, a single-phase liquid argon direct-detection dark matter experiment, were recently reported. At first sight, they seem to provide no new constraints, as the limit lies well within the region already excluded by three different xenon experiments: LUX, PandaX-II, and XENON1T. We point out, however, that this conclusion is not necessarily true, for it is based on the untested assumption that the dark matter particle couples equally to protons and neutrons. For the more general case of isosping-violating dark matter, we find that there are regions in the parameter space where DEAP-3600 actually provides the most stringent limits on the dark matter-proton spin-independent cross section. Such regions correspond to the so-called Xenonphobic dark matter scenario, for which the neutron-to-proton coupling ratio is close to $-0.7$. Our results seem to signal the beginning of a new era in which the complementarity among different direct detection targets will play a crucial role in the determination of the fundamental properties of the dark matter particle.
[ { "created": "Tue, 26 Feb 2019 22:49:22 GMT", "version": "v1" }, { "created": "Mon, 29 Apr 2019 16:36:43 GMT", "version": "v2" } ]
2019-04-30
[ [ "Yaguna", "Carlos E.", "" ] ]
The first-year results from DEAP-3600, a single-phase liquid argon direct-detection dark matter experiment, were recently reported. At first sight, they seem to provide no new constraints, as the limit lies well within the region already excluded by three different xenon experiments: LUX, PandaX-II, and XENON1T. We point out, however, that this conclusion is not necessarily true, for it is based on the untested assumption that the dark matter particle couples equally to protons and neutrons. For the more general case of isosping-violating dark matter, we find that there are regions in the parameter space where DEAP-3600 actually provides the most stringent limits on the dark matter-proton spin-independent cross section. Such regions correspond to the so-called Xenonphobic dark matter scenario, for which the neutron-to-proton coupling ratio is close to $-0.7$. Our results seem to signal the beginning of a new era in which the complementarity among different direct detection targets will play a crucial role in the determination of the fundamental properties of the dark matter particle.
1706.01920
Anthony Fradette
Anthony Fradette, Maxim Pospelov
BBN for the LHC: constraints on lifetimes of the Higgs portal scalars
16 pages, 11 figures
Phys. Rev. D 96, 075033 (2017)
10.1103/PhysRevD.96.075033
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
LHC experiments can provide a remarkable sensitivity to exotic metastable massive particles, decaying with significant displacement from the interaction point. The best sensitivity is achieved to models where the production and decay occur due to different coupling constants, and the lifetime of exotic particles determines the probability of decay within a detector. The lifetimes of such particles can be independently limited from standard cosmology, in particular the Big Bang Nucleosynthesis. In this paper, we analyze the constraints on the simplest scalar model coupled through the Higgs portal, where the production occurs via $h\to SS$, and the decay is induced by the small mixing angle of the Higgs field $h$ and scalar $S$. We find that throughout the most part of the parameter space, $2 m_\mu < m_S < m_h/2$, the lifetimes of exotic particle has to be less than 0.1 seconds, while below $2m_\mu$ it could grow to about a second. The strong constraints on lifetimes are induced by the nucleonic and mesonic decays of scalars that tend to raise the $n/p$ ratio. Strong constraints on lifetimes of the minimal singlet extensions of the Higgs potential is a welcome news for the MATHUSLA proposal that seeks to detect displaced decays of exotic particles produced in the LHC collisions. We also point out how more complicated exotic sectors could evade the BBN lifetime constraints.
[ { "created": "Tue, 6 Jun 2017 18:32:57 GMT", "version": "v1" } ]
2017-11-01
[ [ "Fradette", "Anthony", "" ], [ "Pospelov", "Maxim", "" ] ]
LHC experiments can provide a remarkable sensitivity to exotic metastable massive particles, decaying with significant displacement from the interaction point. The best sensitivity is achieved to models where the production and decay occur due to different coupling constants, and the lifetime of exotic particles determines the probability of decay within a detector. The lifetimes of such particles can be independently limited from standard cosmology, in particular the Big Bang Nucleosynthesis. In this paper, we analyze the constraints on the simplest scalar model coupled through the Higgs portal, where the production occurs via $h\to SS$, and the decay is induced by the small mixing angle of the Higgs field $h$ and scalar $S$. We find that throughout the most part of the parameter space, $2 m_\mu < m_S < m_h/2$, the lifetimes of exotic particle has to be less than 0.1 seconds, while below $2m_\mu$ it could grow to about a second. The strong constraints on lifetimes are induced by the nucleonic and mesonic decays of scalars that tend to raise the $n/p$ ratio. Strong constraints on lifetimes of the minimal singlet extensions of the Higgs potential is a welcome news for the MATHUSLA proposal that seeks to detect displaced decays of exotic particles produced in the LHC collisions. We also point out how more complicated exotic sectors could evade the BBN lifetime constraints.
1208.1055
Martin Poghosyan G.
M. G. Poghosyan
Predictions for pp single diffractive cross section at LHC
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A model based on Gribov's Regge calculus was developed [1] and was proposed to describe diffractive processes. In this note we present numerical vales obtained from [1] for the dependence of single diffraction cross-section on diffractive mass at $\sqrt{s}$ = 0.9, 2.76 and 7 TeV.
[ { "created": "Sun, 5 Aug 2012 22:00:24 GMT", "version": "v1" } ]
2012-08-07
[ [ "Poghosyan", "M. G.", "" ] ]
A model based on Gribov's Regge calculus was developed [1] and was proposed to describe diffractive processes. In this note we present numerical vales obtained from [1] for the dependence of single diffraction cross-section on diffractive mass at $\sqrt{s}$ = 0.9, 2.76 and 7 TeV.
hep-ph/0703221
Louis J. Clavelli
L. Clavelli
Phase Transition to Exact Susy
To appear in Proceedings of Susy06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, Ed. Jonathon L. Feng, American Institute of Physics, 2007
AIPConf.Proc.903:634-637,2007
10.1063/1.2735264
null
hep-ph
null
The anthropic principle is based on the observation that, within narrow bounds, the laws of physics are such as to have allowed the evolution of life. The string theoretic approach to understanding this observation is based on the expectation that the effective potential has an enormous number of local minima with different particle masses and perhaps totally different fundamental couplings and space time topology. The vast majority of these alternative universes are totally inhospitable to life, having, for example, vacuum energies near the natural (Planck) scale. The statistics, however, are assumed to be such that a few of these local minima (and not more) have a low enough vacuum energy and suitable other properties to support life. In the inflationary era, the "multiverse" made successive transitions between the available minima until arriving at our current state of low vacuum energy. String theory, however, also suggests that the absolute minimum of the effective potential is exactly supersymmetric. Questions then arise as to why the inflationary era did not end by a transition to one of these, when will the universe make the phase transition to the exactly supersymmetric ground state, and what will be the properties of this final state.
[ { "created": "Tue, 20 Mar 2007 19:42:24 GMT", "version": "v1" } ]
2008-11-26
[ [ "Clavelli", "L.", "" ] ]
The anthropic principle is based on the observation that, within narrow bounds, the laws of physics are such as to have allowed the evolution of life. The string theoretic approach to understanding this observation is based on the expectation that the effective potential has an enormous number of local minima with different particle masses and perhaps totally different fundamental couplings and space time topology. The vast majority of these alternative universes are totally inhospitable to life, having, for example, vacuum energies near the natural (Planck) scale. The statistics, however, are assumed to be such that a few of these local minima (and not more) have a low enough vacuum energy and suitable other properties to support life. In the inflationary era, the "multiverse" made successive transitions between the available minima until arriving at our current state of low vacuum energy. String theory, however, also suggests that the absolute minimum of the effective potential is exactly supersymmetric. Questions then arise as to why the inflationary era did not end by a transition to one of these, when will the universe make the phase transition to the exactly supersymmetric ground state, and what will be the properties of this final state.
2308.00395
Mojtaba Hosseini
Mojtaba Hosseini, Seyed Yaser Ayazi, Ahmad Mohamadnejad
Gravitational wave effects and phenomenology of a two-component dark matter model
29 pages, 11 figures
Eur.Phys.J.C 84 (2024) 485
10.1140/epjc/s10052-024-12769-8
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study an extension of the Standard Model (SM) which could have two candidates for dark matter (DM) including a Dirac fermion and a vector dark matter (VDM) under a new $U(1)$ gauge group in the hidden sector. The model is classically scale-invariant and the electroweak symmetry breaks because of loop effects. We investigate the parameter space allowed by current experimental constraints and phenomenological bounds. We probe the parameter space of the model in the mass range $1< M_V<5000$ GeV and $1<M_{\psi}<5000$ GeV. It has been shown that there are many points in this mass range that are in agreement with all phenomenological constraints. The electroweak phase transition has been discussed and it has been shown that there is region in the parameter space of the model consistent with DM relic density and direct detection constraints that, at the same time, can lead to first order electroweak phase transition. The gravitational waves produced during the phase transition could be probed by future space-based interferometers such as LISA and BBO.
[ { "created": "Tue, 1 Aug 2023 09:15:56 GMT", "version": "v1" }, { "created": "Wed, 29 Nov 2023 13:58:28 GMT", "version": "v2" }, { "created": "Sat, 11 May 2024 18:08:36 GMT", "version": "v3" } ]
2024-05-14
[ [ "Hosseini", "Mojtaba", "" ], [ "Ayazi", "Seyed Yaser", "" ], [ "Mohamadnejad", "Ahmad", "" ] ]
We study an extension of the Standard Model (SM) which could have two candidates for dark matter (DM) including a Dirac fermion and a vector dark matter (VDM) under a new $U(1)$ gauge group in the hidden sector. The model is classically scale-invariant and the electroweak symmetry breaks because of loop effects. We investigate the parameter space allowed by current experimental constraints and phenomenological bounds. We probe the parameter space of the model in the mass range $1< M_V<5000$ GeV and $1<M_{\psi}<5000$ GeV. It has been shown that there are many points in this mass range that are in agreement with all phenomenological constraints. The electroweak phase transition has been discussed and it has been shown that there is region in the parameter space of the model consistent with DM relic density and direct detection constraints that, at the same time, can lead to first order electroweak phase transition. The gravitational waves produced during the phase transition could be probed by future space-based interferometers such as LISA and BBO.
2312.01380
Bartosz Dziewit
Bartosz Dziewit, Joris Vergeest, Marek Zra{\l}ek
Flavor symmetries in the leptonic Yukawa sector of the 3HDM
7 pages, 0 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
As an extension of the Standard Model (SM), the 3HDM (Three-Higgs-Doublet Model) defines additional relationships among the fermions. In the visible leptonic Yukawa sector of a minimal 3HDM, we determine and classify the existing flavor symmetries under discrete non-abelian groups up to order 1032. The three Higgs doublets form a flavor triplet, and the admission of unfaithful representations enriches the set of candidate flavor transformations greatly. The many existing symmetries give rise (after EWSB) to a large number of inequivalent mass matrices that imply lepton properties, which in turn are evaluated against experimental data. In the 3HDM the mass hierarchy of the charged leptons leads to a too small $\Delta m^2_{21} / \Delta m^2_{32}$ ratio of the neutrinos. More generally, it is proven that the lepton mass matrices implied by discrete flavor symmetries are in disagreement with the observed data for all groups investigated, both when it is assumed that the neutrinos have the Dirac or Majorana nature.
[ { "created": "Sun, 3 Dec 2023 13:01:40 GMT", "version": "v1" } ]
2023-12-05
[ [ "Dziewit", "Bartosz", "" ], [ "Vergeest", "Joris", "" ], [ "Zrałek", "Marek", "" ] ]
As an extension of the Standard Model (SM), the 3HDM (Three-Higgs-Doublet Model) defines additional relationships among the fermions. In the visible leptonic Yukawa sector of a minimal 3HDM, we determine and classify the existing flavor symmetries under discrete non-abelian groups up to order 1032. The three Higgs doublets form a flavor triplet, and the admission of unfaithful representations enriches the set of candidate flavor transformations greatly. The many existing symmetries give rise (after EWSB) to a large number of inequivalent mass matrices that imply lepton properties, which in turn are evaluated against experimental data. In the 3HDM the mass hierarchy of the charged leptons leads to a too small $\Delta m^2_{21} / \Delta m^2_{32}$ ratio of the neutrinos. More generally, it is proven that the lepton mass matrices implied by discrete flavor symmetries are in disagreement with the observed data for all groups investigated, both when it is assumed that the neutrinos have the Dirac or Majorana nature.
hep-ph/0104210
Luis Bettencourt
Luis M. A. Bettencourt, Karen Pao and J. G. Sanderson
Dynamical behavior of spatially inhomogeneous relativistic $\lambda \phi^4$ quantum field theory in the Hartree approximation
22 pages, 8 figures, uses Revtex
Phys.Rev. D65 (2002) 025015
10.1103/PhysRevD.65.025015
MIT-CTP-3107
hep-ph
null
We study the dynamics of a spatially inhomogeneous quantum $\lambda \phi^4$ field theory in 1+1 dimensions in the Hartree approximation. In particular, we investigate the long-time behavior of this approximation in a variety of controlled situations, both at zero and finite temperature. The observed behavior is much richer than that in the spatially homogeneous case. Nevertheless, we show that the fields fail to thermalize in a canonical sense, as expected from analogous results in closely related (mean field) transport theory. We argue that this dynamical approximation is best suited as a means to study the short-time decay of spatially inhomogeneous fields and in the dynamics of coherent quasi-classical inhomogeneous configurations (e.g. solitons) in a background of dynamical self-consistent quantum fluctuations.
[ { "created": "Sat, 21 Apr 2001 01:01:43 GMT", "version": "v1" } ]
2009-11-07
[ [ "Bettencourt", "Luis M. A.", "" ], [ "Pao", "Karen", "" ], [ "Sanderson", "J. G.", "" ] ]
We study the dynamics of a spatially inhomogeneous quantum $\lambda \phi^4$ field theory in 1+1 dimensions in the Hartree approximation. In particular, we investigate the long-time behavior of this approximation in a variety of controlled situations, both at zero and finite temperature. The observed behavior is much richer than that in the spatially homogeneous case. Nevertheless, we show that the fields fail to thermalize in a canonical sense, as expected from analogous results in closely related (mean field) transport theory. We argue that this dynamical approximation is best suited as a means to study the short-time decay of spatially inhomogeneous fields and in the dynamics of coherent quasi-classical inhomogeneous configurations (e.g. solitons) in a background of dynamical self-consistent quantum fluctuations.
hep-ph/9903395
null
Chun Liu
Electroweak Symmetry Breaking due to Confinement
8 pages, revtex, no figure, the discussion on effective superpotential refined
Mod.Phys.Lett. A15 (2000) 525-530
10.1142/S0217732300000517
null
hep-ph
null
Within the framework of gauge mediated supersymmetry breaking, we consider an electroweak symmetry breaking pattern in which there is no conventional $\mu$ term. The pattern is made appealing through realizing it as low energy effective description of a supersymmetric Yang-Mills theory which is of confinement. Phenomenological implications are discussed.
[ { "created": "Thu, 18 Mar 1999 06:59:17 GMT", "version": "v1" }, { "created": "Wed, 28 Apr 1999 07:07:27 GMT", "version": "v2" } ]
2009-10-31
[ [ "Liu", "Chun", "" ] ]
Within the framework of gauge mediated supersymmetry breaking, we consider an electroweak symmetry breaking pattern in which there is no conventional $\mu$ term. The pattern is made appealing through realizing it as low energy effective description of a supersymmetric Yang-Mills theory which is of confinement. Phenomenological implications are discussed.
1301.0287
Mart\'in Gonz\'alez-Alonso
Mart\'in Gonz\'alez-Alonso
Probing non-standard charged-current interactions: from cold neutrons to the LHC
Proceedings of CKM 2012, the 7th International Workshop on the CKM Unitarity Triangle, University of Cincinnati, USA, 28 September - 2 October 2012
null
null
NPAC-13-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that semileptonic decays of light hadrons and nuclei can be used not only to determine the CKM element V_ud with high accuracy, but also as probes of physics beyond the Standard Model. In this talk I review recent works that studied this within an Effective Field Theory framework, comparing the sensitivity of different low-energy and LHC observables. A clear complementarity between low- and high-energy searches it is found.
[ { "created": "Wed, 2 Jan 2013 18:25:33 GMT", "version": "v1" } ]
2013-01-03
[ [ "González-Alonso", "Martín", "" ] ]
It is well known that semileptonic decays of light hadrons and nuclei can be used not only to determine the CKM element V_ud with high accuracy, but also as probes of physics beyond the Standard Model. In this talk I review recent works that studied this within an Effective Field Theory framework, comparing the sensitivity of different low-energy and LHC observables. A clear complementarity between low- and high-energy searches it is found.
hep-ph/0512347
Ying Li
Ying Li, Cai-Dian Lu, Cong-Feng Qiao
Rare decays of B-> J/\psi D^(*) and B->\eta_c D^(*)in pQCD Approach
10 pages, 1 figure
Phys.Rev.D73:094006,2006
10.1103/PhysRevD.73.094006
null
hep-ph
null
Motivated by the recent measurement of the upper limit of ${B}^0 \to J/\psi D$ branching ratio, which is important in accounting for the soft $J/\psi$ production in B decays, we investigate ${B}^0 \to J/\psi D^{(\star)}$ and $\eta_c D^{(\star)}$ decays in perturbative QCD approach based on $k_T$ factorization. Being pure annihilation (W-exchange) decays, these branching ratios are estimated to be at the order of $10^{-5} \sim 10^{-7}$, which are just at the corner of being observable at the $B$ factories. The measurements of these decay channels may help us to understand the QCD dynamics in the corresponding energy scale, especially the reliability of pQCD approach to these processes.
[ { "created": "Wed, 28 Dec 2005 06:52:20 GMT", "version": "v1" } ]
2008-11-26
[ [ "Li", "Ying", "" ], [ "Lu", "Cai-Dian", "" ], [ "Qiao", "Cong-Feng", "" ] ]
Motivated by the recent measurement of the upper limit of ${B}^0 \to J/\psi D$ branching ratio, which is important in accounting for the soft $J/\psi$ production in B decays, we investigate ${B}^0 \to J/\psi D^{(\star)}$ and $\eta_c D^{(\star)}$ decays in perturbative QCD approach based on $k_T$ factorization. Being pure annihilation (W-exchange) decays, these branching ratios are estimated to be at the order of $10^{-5} \sim 10^{-7}$, which are just at the corner of being observable at the $B$ factories. The measurements of these decay channels may help us to understand the QCD dynamics in the corresponding energy scale, especially the reliability of pQCD approach to these processes.
hep-ph/9908299
Javier Rico
Fernando Cornet (Univ. Granada, Spain), Monica Relano (IAC, La Laguna, Spain), Javier Rico (ETH-Zurich, Switzerland)
Four Fermion Contact Terms in Charged Current Processes and Large Extra Dimensions
11 pages, Latex. Some references added
Phys.Rev.D61:037701,2000
10.1103/PhysRevD.61.037701
UG-FT-101/99
hep-ph
null
We study the bounds that can be obtained on four-fermion contact terms from the experimental data for (e+ p -> \bar{nu} X) obtained at HERA and (p \bar{p} -> e \nu), measured at TEVATRON. We compare these bounds with the ones available in the literature. Finally, we apply these results to study the compactification radius in theories with large extra dimensions and we obtain the bound M_c >= 3.3 TeV.
[ { "created": "Mon, 9 Aug 1999 00:14:59 GMT", "version": "v1" }, { "created": "Thu, 16 Sep 1999 08:50:15 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cornet", "Fernando", "", "Univ. Granada, Spain" ], [ "Relano", "Monica", "", "IAC, La Laguna,\n Spain" ], [ "Rico", "Javier", "", "ETH-Zurich, Switzerland" ] ]
We study the bounds that can be obtained on four-fermion contact terms from the experimental data for (e+ p -> \bar{nu} X) obtained at HERA and (p \bar{p} -> e \nu), measured at TEVATRON. We compare these bounds with the ones available in the literature. Finally, we apply these results to study the compactification radius in theories with large extra dimensions and we obtain the bound M_c >= 3.3 TeV.
2209.14219
Georgi Dvali
Gia Dvali
Strong-$CP$ with and without gravity
18 pages
null
null
null
hep-ph gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
Conventionally, the strong-$CP$ problem is assumed to be a naturalness puzzle, with the axion solution sometimes viewed as an ad hoc fix. Gravity is either ignored or taken as a threat for the global Peccei-Quinn symmetry. We explain that the situation is fundamentally different. In gravity, axion is a matter of consistency imposed by the $S$-matrix: Each gauge sector must include axion with exact relaxation of the corresponding $\bar{\theta}$. We show that this favors an alternative and remarkably simple formulation of the axion, fully fixed by the gauge redundancy of QCD, without involvement of a global symmetry. The axion mechanism is a Higgs effect for the QCD $3$-form, ensuring that physics is independent of $\bar{\theta}$ to all orders in operator expansion. A near-future experimental detection of the neutron EDM will be an unambiguous signal of $CP$-violating physics beyond the Standard Model. The axion coupling is tied to the scale of gravity.
[ { "created": "Wed, 28 Sep 2022 16:46:23 GMT", "version": "v1" } ]
2022-09-29
[ [ "Dvali", "Gia", "" ] ]
Conventionally, the strong-$CP$ problem is assumed to be a naturalness puzzle, with the axion solution sometimes viewed as an ad hoc fix. Gravity is either ignored or taken as a threat for the global Peccei-Quinn symmetry. We explain that the situation is fundamentally different. In gravity, axion is a matter of consistency imposed by the $S$-matrix: Each gauge sector must include axion with exact relaxation of the corresponding $\bar{\theta}$. We show that this favors an alternative and remarkably simple formulation of the axion, fully fixed by the gauge redundancy of QCD, without involvement of a global symmetry. The axion mechanism is a Higgs effect for the QCD $3$-form, ensuring that physics is independent of $\bar{\theta}$ to all orders in operator expansion. A near-future experimental detection of the neutron EDM will be an unambiguous signal of $CP$-violating physics beyond the Standard Model. The axion coupling is tied to the scale of gravity.
hep-ph/9511383
Marcello Lissia
Suzhou Huang and Marcello Lissia
The Dimensionally Reduced Effective Theory for Quarks in High Temperature QCD
29 pages, RevTeX 3.0, plus 7 figures (postscript). This is the revised version that will appear in Nuclear Physics B; modifications to the original version leave results unchanged and mostly better clarify motivations and strategy
Nucl.Phys.B480:623-654,1996
10.1016/S0550-3213(96)00463-4
MIT-CTP#2361 and INFNCA-TH-94-25
hep-ph hep-lat nucl-th
null
We show that QCD undergoes dimensional reduction at high temperatures also in the quark sector. In the kinematic region relevant to screening physics, where the lowest Matsubara modes are close to their ``mass-shells'', all static Green's functions involving both quarks and gluons, are reproducible in the high-$T$ limit by a renormalizable three dimensional Lagrangian up to order $\tilde{g}^2(T)\sim 1/ln T$. This three dimensional theory only contains explicitly the lightest bosonic and fermionic Matsubara modes, while the heavier modes correct the tree-level couplings and generate extra local vertices. We also find that the quark degrees of freedom that have been retained in the reduced theory are nonrelativistic in the high-$T$ limit. We then improve our result to order $\tilde{g}^4(T)$ through an explicit nonrelativistic expansion, in the spirit of the heavy quark effective theory. This effective theory is relevant for studying QCD screening phenomena with observables made from quarks, e.g. mesonic and baryonic currents, already at temperatures not much higher than the chiral transition temperature $T_c$.
[ { "created": "Tue, 21 Nov 1995 15:24:20 GMT", "version": "v1" }, { "created": "Mon, 23 Sep 1996 14:49:39 GMT", "version": "v2" } ]
2011-01-04
[ [ "Huang", "Suzhou", "" ], [ "Lissia", "Marcello", "" ] ]
We show that QCD undergoes dimensional reduction at high temperatures also in the quark sector. In the kinematic region relevant to screening physics, where the lowest Matsubara modes are close to their ``mass-shells'', all static Green's functions involving both quarks and gluons, are reproducible in the high-$T$ limit by a renormalizable three dimensional Lagrangian up to order $\tilde{g}^2(T)\sim 1/ln T$. This three dimensional theory only contains explicitly the lightest bosonic and fermionic Matsubara modes, while the heavier modes correct the tree-level couplings and generate extra local vertices. We also find that the quark degrees of freedom that have been retained in the reduced theory are nonrelativistic in the high-$T$ limit. We then improve our result to order $\tilde{g}^4(T)$ through an explicit nonrelativistic expansion, in the spirit of the heavy quark effective theory. This effective theory is relevant for studying QCD screening phenomena with observables made from quarks, e.g. mesonic and baryonic currents, already at temperatures not much higher than the chiral transition temperature $T_c$.
1304.1184
Joachim Kopp
Joachim Kopp (MPIK Heidelberg)
Constraints on dark matter annihilation from AMS-02 results
6 pages, 2 figures, v2: improved treatment of astrophysical uncertainties, improved discussion, matches published version
Phys. Rev. D 88, 076013 (2013)
10.1103/PhysRevD.88.076013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use recently released data on the positron-to-electron ratio in cosmic rays from the AMS-02 experiment to constrain dark matter annihilation in the Milky Way. Due to the yet unexplained positron excess, limits are generally weaker than those obtained using other probes, especially gamma rays. This also means that explaining the positron excess in terms of dark matter annihilation is difficult. Only if very conservative assumptions on the dark matter distribution in the Galactic Center region are adopted, it may be possible to accommodate dark matter annihilating to leptons with a cross section above 10^-24 cm^3/sec. We comment on several theoretical mechanisms to explain such large annihilation cross sections.
[ { "created": "Wed, 3 Apr 2013 20:55:25 GMT", "version": "v1" }, { "created": "Wed, 30 Oct 2013 14:52:56 GMT", "version": "v2" } ]
2013-10-31
[ [ "Kopp", "Joachim", "", "MPIK Heidelberg" ] ]
We use recently released data on the positron-to-electron ratio in cosmic rays from the AMS-02 experiment to constrain dark matter annihilation in the Milky Way. Due to the yet unexplained positron excess, limits are generally weaker than those obtained using other probes, especially gamma rays. This also means that explaining the positron excess in terms of dark matter annihilation is difficult. Only if very conservative assumptions on the dark matter distribution in the Galactic Center region are adopted, it may be possible to accommodate dark matter annihilating to leptons with a cross section above 10^-24 cm^3/sec. We comment on several theoretical mechanisms to explain such large annihilation cross sections.
hep-ph/0307171
Enrico Lunghi
Andri Hardmeier, Enrico Lunghi, Dan Pirjol, Daniel Wyler
Subleading collinear operators and their matrix elements
28 pages, 1 figure, axodraw.sty required, few typos corrected
Nucl.Phys. B682 (2004) 150-182
10.1016/j.nuclphysb.2004.01.022
ZU-TH 07/03
hep-ph
null
We discuss the most general form of the leading power suppressed collinear operators in the soft-collinear effective theory. Such operators appear in the description of power corrections to exclusive heavy flavor decays into energetic light hadrons. Reparametrization invariance in the SCET provides powerful constraints on the Wilson coefficients of the subleading collinear operators. We present explicit results for the matrix elements of these operators on pseudoscalar and vector mesons, which are expressed in terms of twist-2 and twist-3 light-cone wave functions. We consistently include the effects of three-particle light-cone distribution amplitudes and find that their impact could be of phenomenological relevance.
[ { "created": "Sun, 13 Jul 2003 20:44:34 GMT", "version": "v1" }, { "created": "Tue, 19 Aug 2003 10:04:05 GMT", "version": "v2" }, { "created": "Mon, 12 Jun 2006 21:17:45 GMT", "version": "v3" } ]
2009-11-10
[ [ "Hardmeier", "Andri", "" ], [ "Lunghi", "Enrico", "" ], [ "Pirjol", "Dan", "" ], [ "Wyler", "Daniel", "" ] ]
We discuss the most general form of the leading power suppressed collinear operators in the soft-collinear effective theory. Such operators appear in the description of power corrections to exclusive heavy flavor decays into energetic light hadrons. Reparametrization invariance in the SCET provides powerful constraints on the Wilson coefficients of the subleading collinear operators. We present explicit results for the matrix elements of these operators on pseudoscalar and vector mesons, which are expressed in terms of twist-2 and twist-3 light-cone wave functions. We consistently include the effects of three-particle light-cone distribution amplitudes and find that their impact could be of phenomenological relevance.
1904.05359
Haolin Li
Hao-Lin Li, Ling-Xiao Xu, Jiang-Hao Yu, Shou-Hua Zhu
EFTs meet Higgs Nonlinearity, Compositeness and (Neutral) Naturalness
46 pages, 12 figures, 10 tables
null
10.1007/JHEP09(2019)010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Composite Higgs and neutral-naturalness models are popular scenarios in which the Higgs boson is a pseudo Nambu-Goldstone boson, and naturalness problem is addressed by composite top partners. Since the standard model effective field theory (SMEFT) with dimension-six operators cannot fully retain the information of Higgs nonlinearity due to its PNGB nature, we systematically construct low energy Lagrangian in which the information of compositeness and Higgs nonlinearity are encoded in the form factors, the two-point functions in the top sector. We classify naturalness conditions in various scenarios, and first present these form factors in composite neutral naturalness models. After extracting out Higgs effective couplings from these form factors and performing the global fit, we find the value of Higgs top coupling could still be larger than the standard model one if the top quark is embedded in the higher dimensional representations. Also we find the impact of Higgs nonlinearity is enhanced by the large mass splitting between composite states. In this case, pattern of the correlation between the $t\bar{t}h$ and $t\bar{t}hh$ couplings is quite different for the linear and nonlinear Higgs descriptions.
[ { "created": "Wed, 10 Apr 2019 18:00:01 GMT", "version": "v1" }, { "created": "Wed, 22 May 2019 03:57:46 GMT", "version": "v2" } ]
2019-10-02
[ [ "Li", "Hao-Lin", "" ], [ "Xu", "Ling-Xiao", "" ], [ "Yu", "Jiang-Hao", "" ], [ "Zhu", "Shou-Hua", "" ] ]
Composite Higgs and neutral-naturalness models are popular scenarios in which the Higgs boson is a pseudo Nambu-Goldstone boson, and naturalness problem is addressed by composite top partners. Since the standard model effective field theory (SMEFT) with dimension-six operators cannot fully retain the information of Higgs nonlinearity due to its PNGB nature, we systematically construct low energy Lagrangian in which the information of compositeness and Higgs nonlinearity are encoded in the form factors, the two-point functions in the top sector. We classify naturalness conditions in various scenarios, and first present these form factors in composite neutral naturalness models. After extracting out Higgs effective couplings from these form factors and performing the global fit, we find the value of Higgs top coupling could still be larger than the standard model one if the top quark is embedded in the higher dimensional representations. Also we find the impact of Higgs nonlinearity is enhanced by the large mass splitting between composite states. In this case, pattern of the correlation between the $t\bar{t}h$ and $t\bar{t}hh$ couplings is quite different for the linear and nonlinear Higgs descriptions.
0710.4528
Joern Kersten
Joern Kersten, Kai Schmidt-Hoberg
The Gravitino-Stau Scenario after Catalyzed BBN
1+14 pages, 6 figures; v2: minor clarifications, 1 reference added, matches version to appear in JCAP
JCAP 0801:011,2008
10.1088/1475-7516/2008/01/011
TUM-HEP 679/07
hep-ph
null
We consider the impact of Catalyzed Big Bang Nucleosynthesis on theories with a gravitino LSP and a charged slepton NLSP. In models where the gravitino to gaugino mass ratio is bounded from below, such as gaugino-mediated SUSY breaking, we derive a lower bound on the gaugino mass parameter m_1/2. As a concrete example, we determine the parameter space of gaugino mediation that is compatible with all cosmological constraints.
[ { "created": "Wed, 24 Oct 2007 18:30:28 GMT", "version": "v1" }, { "created": "Wed, 12 Dec 2007 14:21:15 GMT", "version": "v2" } ]
2009-01-06
[ [ "Kersten", "Joern", "" ], [ "Schmidt-Hoberg", "Kai", "" ] ]
We consider the impact of Catalyzed Big Bang Nucleosynthesis on theories with a gravitino LSP and a charged slepton NLSP. In models where the gravitino to gaugino mass ratio is bounded from below, such as gaugino-mediated SUSY breaking, we derive a lower bound on the gaugino mass parameter m_1/2. As a concrete example, we determine the parameter space of gaugino mediation that is compatible with all cosmological constraints.
0804.4571
Mina Ketan Parida
M. K. Parida (NISER, Bhubaneswar)
Intermediate left-right gauge symmetry, unification of couplings and fermion masses in SUSY $SO(10)\times S_4$
Minor clarification and few references added to match the published version
Phys.Rev.D78:053004,2008
10.1103/PhysRevD.78.053004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If left-right gauge theory occurs as an intermediate symmetry in a GUT then, apart from other advantages, it is possible to obtain the see-saw scale necessary to understand small neutrino masses with Majorana coupling of order unity. Barring threshold or non-renormalizable gravitational effects, or assumed presence of additional light scalar particles of unprescribed origin, all other attempts to achieve manifest one-loop gauge coupling unification in SUSY SO(10) with left-right intermediate symmetry have not been successful so far. Attributing this failure to lack of flavor symmetry in the GUT, we show how the spontaneous symmetry breaking of $SO(10)\times S_4$ leads to such intermediate scale extending over a wide range, $M_R \simeq 5\times 10^{9}$ GeV to $10^{15}$ GeV. All the charged fermion masses are fitted at the see-saw scale, $M_N\simeq M_R \simeq 4 \times 10^{13}$ GeV which is obtained with Majorana coupling $f_0 \simeq 1$. Using a constrained parametrization in which CP-violation originates only from quark sector, besides other predictions made in the neutrino sector, the reactor mixing angle is found to be $\theta_{13} \simeq 3^{\circ} - 5^{\circ}$ which is in the range accessible to ongoing and planned experiments. The leptonic Dirac phase turns out to be $\delta \sim 2.9- 3.1$ radians with Jarlskog invariant $J \sim 2.95 \times 10^{-5} - 10^{-3}$.
[ { "created": "Tue, 29 Apr 2008 12:42:26 GMT", "version": "v1" }, { "created": "Tue, 16 Sep 2008 12:32:33 GMT", "version": "v2" } ]
2009-01-09
[ [ "Parida", "M. K.", "", "NISER, Bhubaneswar" ] ]
If left-right gauge theory occurs as an intermediate symmetry in a GUT then, apart from other advantages, it is possible to obtain the see-saw scale necessary to understand small neutrino masses with Majorana coupling of order unity. Barring threshold or non-renormalizable gravitational effects, or assumed presence of additional light scalar particles of unprescribed origin, all other attempts to achieve manifest one-loop gauge coupling unification in SUSY SO(10) with left-right intermediate symmetry have not been successful so far. Attributing this failure to lack of flavor symmetry in the GUT, we show how the spontaneous symmetry breaking of $SO(10)\times S_4$ leads to such intermediate scale extending over a wide range, $M_R \simeq 5\times 10^{9}$ GeV to $10^{15}$ GeV. All the charged fermion masses are fitted at the see-saw scale, $M_N\simeq M_R \simeq 4 \times 10^{13}$ GeV which is obtained with Majorana coupling $f_0 \simeq 1$. Using a constrained parametrization in which CP-violation originates only from quark sector, besides other predictions made in the neutrino sector, the reactor mixing angle is found to be $\theta_{13} \simeq 3^{\circ} - 5^{\circ}$ which is in the range accessible to ongoing and planned experiments. The leptonic Dirac phase turns out to be $\delta \sim 2.9- 3.1$ radians with Jarlskog invariant $J \sim 2.95 \times 10^{-5} - 10^{-3}$.
hep-ph/0205100
Anirban Kundu
Anirban Kundu (Jadavpur U.)
B decays and Supersymmetry
LaTex file of working group talk presented at WHEPP-7, HRI, Allahabad, Jan. 2002
Pramana 60:345-352,2003
10.1007/BF02706413
null
hep-ph
null
I discuss how supersymmetry affects various observables in B decays, and point out the interesting channels in the context of B factories.
[ { "created": "Fri, 10 May 2002 12:15:10 GMT", "version": "v1" } ]
2010-11-23
[ [ "Kundu", "Anirban", "", "Jadavpur U." ] ]
I discuss how supersymmetry affects various observables in B decays, and point out the interesting channels in the context of B factories.
hep-ph/9910258
Burkert
Volker D. Burkert (Jefferson Laboratory)
Probing the structure of Nucleons in Electromagbetic Interactions
9 pages, 6 figures, plenary talk at PANIC99
Nucl.Phys. A663 (2000) 29-37
10.1016/S0375-9474(99)00569-2
null
hep-ph
null
Open problems in the study of the nucleon structure using electromagnetic probes are discussed. The focus is on experimental aspects in the regime of strong interaction QCD. Significant progress in our understanding of the nucleon structure in this domain of QCD may be expected in the first decade of the next millenium. This is due to major experimental and theoretical efforts currently underway in this field.
[ { "created": "Wed, 6 Oct 1999 22:50:14 GMT", "version": "v1" } ]
2009-10-31
[ [ "Burkert", "Volker D.", "", "Jefferson Laboratory" ] ]
Open problems in the study of the nucleon structure using electromagnetic probes are discussed. The focus is on experimental aspects in the regime of strong interaction QCD. Significant progress in our understanding of the nucleon structure in this domain of QCD may be expected in the first decade of the next millenium. This is due to major experimental and theoretical efforts currently underway in this field.
hep-ph/0510096
Yogiro Hama
Yogiro Hama, Rone P.G. Andrade, Frederique Grassi, Otavio Socolowski Jr, Takeshi Kodama, and Bernardo Tavares, S. S. Padula
3D Relativistic Hydrodynamic Computations Using Lattice-QCD-Inspired Equations of State
10 pages, 16 figures, prepared for Quark Matter 2005 Conference
Nucl.Phys. A774 (2006) 169-178
10.1016/j.nuclphysa.2006.06.024
null
hep-ph
null
In this communication, we report results of three-dimensional hydrodynamic computations, by using equations of state with a critical end point as suggested by the lattice QCD. Some of the results are an increase of the multiplicity in the mid-rapidity region and a larger elliptic-flow parameter v2. We discuss also the effcts of the initial-condition fluctuations and the continuous emission.
[ { "created": "Fri, 7 Oct 2005 15:30:04 GMT", "version": "v1" }, { "created": "Fri, 28 Oct 2005 17:47:17 GMT", "version": "v2" }, { "created": "Mon, 14 Nov 2005 14:16:08 GMT", "version": "v3" } ]
2009-11-11
[ [ "Hama", "Yogiro", "" ], [ "Andrade", "Rone P. G.", "" ], [ "Grassi", "Frederique", "" ], [ "Socolowski", "Otavio", "Jr" ], [ "Kodama", "Takeshi", "" ], [ "Tavares", "Bernardo", "" ], [ "Padula", "S. S.", ""...
In this communication, we report results of three-dimensional hydrodynamic computations, by using equations of state with a critical end point as suggested by the lattice QCD. Some of the results are an increase of the multiplicity in the mid-rapidity region and a larger elliptic-flow parameter v2. We discuss also the effcts of the initial-condition fluctuations and the continuous emission.
hep-ph/9706488
Dey Mira
Jishnu Dey, Mira Dey, T. Frederico, Lauro Tomio
Scaling Law for Baryon Coupling to its Current and its possible applications
10 pages, 2 figures, 1 tex picture and 1 ps picture
Mod.Phys.Lett. A12 (1997) 2193-2202
10.1142/S0217732397002247
null
hep-ph
null
The baryon- coupling to its current ($\lambda_{B}$), in conventional QCD sum rule calculations (QCDSR), is shown to scale as the cubic power of the baryon mass, $M_B$. Some theoretical justification for it comes from a simple light-cone model and also general scaling arguments for QCD. But more importantly, taken as a phenomenological ansatz for the present, this may find very good use in current explorations of possible applications of QCDSR to baryon physics both at temperature $T = 0$, $T \ne 0$ and/or density $\rho = 0$, $\rho \ne 0$.
[ { "created": "Tue, 24 Jun 1997 15:52:40 GMT", "version": "v1" } ]
2009-10-30
[ [ "Dey", "Jishnu", "" ], [ "Dey", "Mira", "" ], [ "Frederico", "T.", "" ], [ "Tomio", "Lauro", "" ] ]
The baryon- coupling to its current ($\lambda_{B}$), in conventional QCD sum rule calculations (QCDSR), is shown to scale as the cubic power of the baryon mass, $M_B$. Some theoretical justification for it comes from a simple light-cone model and also general scaling arguments for QCD. But more importantly, taken as a phenomenological ansatz for the present, this may find very good use in current explorations of possible applications of QCDSR to baryon physics both at temperature $T = 0$, $T \ne 0$ and/or density $\rho = 0$, $\rho \ne 0$.
1803.08517
Jacobo Ruiz de Elvira
A. G\'omez Nicola and J. Ruiz de Elvira
Chiral and $U(1)_A$ restoration for the scalar/pseudoscalar meson nonets
28 pages and 16 figures
Phys. Rev. D 98, 014020 (2018)
10.1103/PhysRevD.98.014020
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the restoration pattern of the members of the scalar and pseudoscalar meson nonets under chiral $O(4)$ and $U(1)_A$ symmetries. For that purpose, we exploit QCD Ward Identities (WI), which allow one to relate susceptibilities with quark condensates, as well as susceptibility differences with meson vertices. In addition, we consider the low-energy realization of QCD provided by $U(3)$ Chiral Perturbation Theory (ChPT) at finite temperature to perform a full analysis of the different correlators involved. Our analysis suggests $U(1)_A$ partner restoration if chiral symmetry partners are also degenerated. This is also confirmed by the ChPT analysis when the light chiral limit is reached. Partner degeneration for the $I=1/2$ sector, the behavior of $I=0$ mixing and the temperature scaling of meson masses predicted by WI are also studied. Special attention is paid to the connection of our results with recent lattice analyses.
[ { "created": "Thu, 22 Mar 2018 18:00:18 GMT", "version": "v1" } ]
2018-07-25
[ [ "Nicola", "A. Gómez", "" ], [ "de Elvira", "J. Ruiz", "" ] ]
We analyze the restoration pattern of the members of the scalar and pseudoscalar meson nonets under chiral $O(4)$ and $U(1)_A$ symmetries. For that purpose, we exploit QCD Ward Identities (WI), which allow one to relate susceptibilities with quark condensates, as well as susceptibility differences with meson vertices. In addition, we consider the low-energy realization of QCD provided by $U(3)$ Chiral Perturbation Theory (ChPT) at finite temperature to perform a full analysis of the different correlators involved. Our analysis suggests $U(1)_A$ partner restoration if chiral symmetry partners are also degenerated. This is also confirmed by the ChPT analysis when the light chiral limit is reached. Partner degeneration for the $I=1/2$ sector, the behavior of $I=0$ mixing and the temperature scaling of meson masses predicted by WI are also studied. Special attention is paid to the connection of our results with recent lattice analyses.
2404.18358
Ying Zhang
Ying Zhang
CP violation in the CKM mixing for degenerate quark masses
9 pages
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
CP violation in the CKM mixing is discussed for the case of quark mass degeneracy that is approximate in the quark mass hierarchy limit. Differing from the traditional understanding of CP vanishing for degenerate masses, we find degenerate symmetry plays a non-trivial role in CP violation. The minimal flavor structure model is reviewed to demonstrate the role of degenerate symmetry in quark flavor mixing, particularly in CP violation. This relation between mass hierarchy and CP violation helps us understand the origin of CP violation and assists the construction of the flavor model.
[ { "created": "Mon, 29 Apr 2024 01:37:15 GMT", "version": "v1" } ]
2024-04-30
[ [ "Zhang", "Ying", "" ] ]
CP violation in the CKM mixing is discussed for the case of quark mass degeneracy that is approximate in the quark mass hierarchy limit. Differing from the traditional understanding of CP vanishing for degenerate masses, we find degenerate symmetry plays a non-trivial role in CP violation. The minimal flavor structure model is reviewed to demonstrate the role of degenerate symmetry in quark flavor mixing, particularly in CP violation. This relation between mass hierarchy and CP violation helps us understand the origin of CP violation and assists the construction of the flavor model.
hep-ph/0411050
Bennie F. L. Ward
B.F.L. Ward (Department Department of Physics, Baylor University, Waco, Texas, USA)
Quantum Corrections to Newton's Law in Resummed Quantum Gravity
4 pages, 1 figure; presented by B.F.L. Ward at DPF2004
Int.J.Mod.Phys. A20 (2005) 3502-3506
10.1142/S0217751X05026832
BU-HEPP-04-10
hep-ph
null
We present the elements of resummed quantum gravity, a new approach to quantum gravity based on the work of Feynman using the simplest example of a scalar field as the representative matter. We show that we get a UV finite quantum correction to Newton's law.
[ { "created": "Wed, 3 Nov 2004 15:42:14 GMT", "version": "v1" } ]
2009-11-10
[ [ "Ward", "B. F. L.", "", "Department Department of Physics, Baylor University,\n Waco, Texas, USA" ] ]
We present the elements of resummed quantum gravity, a new approach to quantum gravity based on the work of Feynman using the simplest example of a scalar field as the representative matter. We show that we get a UV finite quantum correction to Newton's law.
2111.07427
Piotr Korcyl
Piotr Korcyl
Finite volume effects in the McLerran-Venugopalan initial condition for the JIMWLK equation
8 pages, 7 figures
null
10.1140/epjc/s10052-022-10310-3
null
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
We revisit the numerical construction of the initial condition for the dipole amplitude from the McLerran-Venugopalan model in the context of the JIMWLK evolution equation. We observe large finite volume effects induced by the Poisson equation formulated on a torus. We show that the situation can be partially cured by introducing an infrared regularization. We propose a procedure that has negligible finite volume corrections. The control of the finite volume and finite lattice spacings effects is crucial when considering the numerical solutions of the JIMWLK evolution equation with the collinear improvement.
[ { "created": "Sun, 14 Nov 2021 19:30:20 GMT", "version": "v1" } ]
2022-05-11
[ [ "Korcyl", "Piotr", "" ] ]
We revisit the numerical construction of the initial condition for the dipole amplitude from the McLerran-Venugopalan model in the context of the JIMWLK evolution equation. We observe large finite volume effects induced by the Poisson equation formulated on a torus. We show that the situation can be partially cured by introducing an infrared regularization. We propose a procedure that has negligible finite volume corrections. The control of the finite volume and finite lattice spacings effects is crucial when considering the numerical solutions of the JIMWLK evolution equation with the collinear improvement.
0905.2139
Kaminski Robert
R. Kaminski, R. Garcia-Martin, J.R. Pelaez, F.J. Yndurain
Once and twice subtracted dispersion relations in the analysis of pi pi amplitudes
6 pages, to appear in proceedings of ExcitedQCD 09 workshop, 8-14 February 2009, Zakopane (Poland)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Once and twice subtracted crossing symmetric dispersion relations applied to $\pi\pi \to \pi\pi$ scattering data are analyzed and compared. Both sets of dispersion relations can be used to test the $\pi\pi$ amplitudes in low partial waves up to about 1 GeV. We show how once subtracted dispersion relations can provide stronger constraints for $\pi\pi$ amplitudes than twice subtracted ones in the 400 to 1100 MeV range, given the same experimental input.
[ { "created": "Wed, 13 May 2009 16:24:25 GMT", "version": "v1" } ]
2009-05-14
[ [ "Kaminski", "R.", "" ], [ "Garcia-Martin", "R.", "" ], [ "Pelaez", "J. R.", "" ], [ "Yndurain", "F. J.", "" ] ]
Once and twice subtracted crossing symmetric dispersion relations applied to $\pi\pi \to \pi\pi$ scattering data are analyzed and compared. Both sets of dispersion relations can be used to test the $\pi\pi$ amplitudes in low partial waves up to about 1 GeV. We show how once subtracted dispersion relations can provide stronger constraints for $\pi\pi$ amplitudes than twice subtracted ones in the 400 to 1100 MeV range, given the same experimental input.
2011.13619
Wei Chao
Wei Chao, JIan-guo Jiang and Min Su
Probing Bottom-flavored Scalar Dark Matters at Loop Level
23 pages, 10 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we consider loop corrections to the spin-independent WIMP-nucleon scattering cross section in bottom-quark flavored scalar-type dark matter models. We focus on two scenarios: (a) a complex scalar dark matter with a scalar particle as the mediator; and (b) a real scalar dark matter with a vector boson as the mediator. In both scenarios, the direct detection cross sections are either spin-dependent or kinematically forbidden at the tree-level. Corrections induced by the WIMP-gluon effective operator, scalar-type WIMP-quark effective operator, and the twist-2 effective operator are calculated. Numerical results show that loop induced spin-independent WIMP-nucleon scattering cross sections are quite considerable in both scenarios.
[ { "created": "Fri, 27 Nov 2020 09:21:10 GMT", "version": "v1" } ]
2020-11-30
[ [ "Chao", "Wei", "" ], [ "Jiang", "JIan-guo", "" ], [ "Su", "Min", "" ] ]
In this paper we consider loop corrections to the spin-independent WIMP-nucleon scattering cross section in bottom-quark flavored scalar-type dark matter models. We focus on two scenarios: (a) a complex scalar dark matter with a scalar particle as the mediator; and (b) a real scalar dark matter with a vector boson as the mediator. In both scenarios, the direct detection cross sections are either spin-dependent or kinematically forbidden at the tree-level. Corrections induced by the WIMP-gluon effective operator, scalar-type WIMP-quark effective operator, and the twist-2 effective operator are calculated. Numerical results show that loop induced spin-independent WIMP-nucleon scattering cross sections are quite considerable in both scenarios.
hep-ph/0610149
Ahmed Ali
Ahmed Ali, Alexander Parkhomenko
$ B \to (\rho, \omega)\gamma$ Decays and CKM Phenomenology
15 pages, 3 figures; presented by Alexander Parkhomenko at the 14th International Seminar on High Energy Physics: Quarks-2006, St. Petersburg, Russian Federation, 19 - 25 May, 2006 (to appear in the proceedings)
null
null
DESY 06-187
hep-ph
null
We review and update the branching ratios for the $B \to (\rho,\omega) \gamma$ decays, calculated in the QCD factorization approach in the next-to-leading order (NLO) in the strong coupling $\alpha_s$ and to leading power in $\Lambda_{\rm QCD}/m_b$. The corrections take into account the vertex, hard-spectator and annihilation contributions and are found to be large. Theoretical expectations for the branching ratios, CP-asymmetry, isospin- and $SU (3)_{\rm F}$-violating ratios in the $B \to \rho\gamma$ and $B \to \omega\gamma$ decays are presented and compared with the available data.
[ { "created": "Thu, 12 Oct 2006 10:43:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ali", "Ahmed", "" ], [ "Parkhomenko", "Alexander", "" ] ]
We review and update the branching ratios for the $B \to (\rho,\omega) \gamma$ decays, calculated in the QCD factorization approach in the next-to-leading order (NLO) in the strong coupling $\alpha_s$ and to leading power in $\Lambda_{\rm QCD}/m_b$. The corrections take into account the vertex, hard-spectator and annihilation contributions and are found to be large. Theoretical expectations for the branching ratios, CP-asymmetry, isospin- and $SU (3)_{\rm F}$-violating ratios in the $B \to \rho\gamma$ and $B \to \omega\gamma$ decays are presented and compared with the available data.
2306.00189
Giancarlo Rossi
Giancarlo Rossi
A road to an elementary particle physics model with no Higgs -- II
33 pages, 7 figures
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
This is the second of two companion papers in which we continue developing the construction of an elementary particle model with no Higgs. Here we show that the recently identified non-perturbative field-theoretical feature, alternative to the Higgs mechanism and capable of giving masses to quarks, Tera-quarks and $W$, can also provide mass to leptons and Tera-leptons when the model is extended to include, besides strong, Tera-strong and weak interactions, also hypercharge. In the present approach elementary fermion masses are not free parameters but are determined by the dynamics of the theory. We derive parametric formulae for elementary particle masses from which we can ``predict'' the order of magnitude of the scale of the new Tera-interaction and get crude numerical estimates for mass ratios in fair agreement with phenomenology. The interest of considering elementary particle models endowed with this kind of non-perturbative mass generation mechanism is that they allow solving some of the conceptual problems of the present formulation of the Standard Model, namely origin of the electroweak scale and naturalness.
[ { "created": "Wed, 31 May 2023 21:10:50 GMT", "version": "v1" }, { "created": "Sat, 4 Nov 2023 14:19:48 GMT", "version": "v2" } ]
2023-11-07
[ [ "Rossi", "Giancarlo", "" ] ]
This is the second of two companion papers in which we continue developing the construction of an elementary particle model with no Higgs. Here we show that the recently identified non-perturbative field-theoretical feature, alternative to the Higgs mechanism and capable of giving masses to quarks, Tera-quarks and $W$, can also provide mass to leptons and Tera-leptons when the model is extended to include, besides strong, Tera-strong and weak interactions, also hypercharge. In the present approach elementary fermion masses are not free parameters but are determined by the dynamics of the theory. We derive parametric formulae for elementary particle masses from which we can ``predict'' the order of magnitude of the scale of the new Tera-interaction and get crude numerical estimates for mass ratios in fair agreement with phenomenology. The interest of considering elementary particle models endowed with this kind of non-perturbative mass generation mechanism is that they allow solving some of the conceptual problems of the present formulation of the Standard Model, namely origin of the electroweak scale and naturalness.
2103.02569
Alexandros Karam Dr.
Alexandros Karam, Tommi Markkanen, Luca Marzola, Sami Nurmi, Martti Raidal, Arttu Rajantie
Higgs-like spectator field as the origin of structure
Figures modified, analysis extended, references added, matches published version
null
10.1140/epjc/s10052-021-09417-w
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We show that the observed primordial perturbations can be entirely sourced by a light spectator scalar field with a quartic potential, akin to the Higgs boson, provided that the field is sufficiently displaced from vacuum during inflation. The framework relies on the indirect modulation of reheating, which is implemented without any direct coupling between the spectator field and the inflaton and does not require non-renormalisable interactions. The scenario gives rise to local non-Gaussianity with $f_{\rm NL}\simeq 5$ as the typical signal. As an example model where the indirect modulation mechanism is realised for the Higgs boson, we study the Standard Model extended with right-handed neutrinos. For the Standard Model running we find, however, that the scenario analysed does not seem to produce the observed perturbation.
[ { "created": "Wed, 3 Mar 2021 18:10:56 GMT", "version": "v1" }, { "created": "Tue, 28 Sep 2021 14:01:26 GMT", "version": "v2" } ]
2021-09-29
[ [ "Karam", "Alexandros", "" ], [ "Markkanen", "Tommi", "" ], [ "Marzola", "Luca", "" ], [ "Nurmi", "Sami", "" ], [ "Raidal", "Martti", "" ], [ "Rajantie", "Arttu", "" ] ]
We show that the observed primordial perturbations can be entirely sourced by a light spectator scalar field with a quartic potential, akin to the Higgs boson, provided that the field is sufficiently displaced from vacuum during inflation. The framework relies on the indirect modulation of reheating, which is implemented without any direct coupling between the spectator field and the inflaton and does not require non-renormalisable interactions. The scenario gives rise to local non-Gaussianity with $f_{\rm NL}\simeq 5$ as the typical signal. As an example model where the indirect modulation mechanism is realised for the Higgs boson, we study the Standard Model extended with right-handed neutrinos. For the Standard Model running we find, however, that the scenario analysed does not seem to produce the observed perturbation.
1004.5444
Wenyu Wang
Wen-Yu Wang, Yue-Liang Wu, Fang Ye
Heavy Quark Expansion in 1/\hat{m}_Q and |V_{cb}| Extraction
21 pages, 11 figures
J.Phys.G38:045004,2011
10.1088/0954-3899/38/4/045004
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
The dressed heavy quark mass \hat{m}_Q=m_Q+\bar{{\Lambda}} with \bar{{\Lambda}} being the binding energy is introduced to characterize the heavy hadrons containing a single heavy quark. A heavy quark expansion in terms of the inverse of the dressed heavy quark mass 1/\hat{m}_Q is presented with a complete decomposition of the full field and integrating out the small components. The heavy quark-antiquark coupling effects are included in the finite mass corrections. It is shown that the 1/\hat{m}_Q expansion is more favorable in application. The extraction of |V_{cb}| from exclusive B decays is studied by using such a new expansion approach.
[ { "created": "Fri, 30 Apr 2010 03:28:11 GMT", "version": "v1" } ]
2011-03-18
[ [ "Wang", "Wen-Yu", "" ], [ "Wu", "Yue-Liang", "" ], [ "Ye", "Fang", "" ] ]
The dressed heavy quark mass \hat{m}_Q=m_Q+\bar{{\Lambda}} with \bar{{\Lambda}} being the binding energy is introduced to characterize the heavy hadrons containing a single heavy quark. A heavy quark expansion in terms of the inverse of the dressed heavy quark mass 1/\hat{m}_Q is presented with a complete decomposition of the full field and integrating out the small components. The heavy quark-antiquark coupling effects are included in the finite mass corrections. It is shown that the 1/\hat{m}_Q expansion is more favorable in application. The extraction of |V_{cb}| from exclusive B decays is studied by using such a new expansion approach.
1309.7259
Francisco Campanario
Francisco Campanario, Nicolas Kaiser, Dieter Zeppenfeld
W &gamma; production in vector boson fusion at NLO in QCD
5 pages, 5 figures
Phys. Rev. D 89, 014009 (2014)
10.1103/PhysRevD.89.014009
FTUV-13-0930, IFIC/13-67, KA-TP-27-2013, LPN13-063, SFB/CPP-13-70
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The next-to-leading order QCD corrections to W gamma production in association with two jets via vector boson fusion are calculated, including the leptonic decay of the W with full off-shell effects and spin correlations. The process lends itself to a test of quartic gauge couplings. The next-to-leading order corrections reduce the scale uncertainty significantly and show a non-trivial phase space dependence.
[ { "created": "Fri, 27 Sep 2013 15:02:17 GMT", "version": "v1" } ]
2014-01-15
[ [ "Campanario", "Francisco", "" ], [ "Kaiser", "Nicolas", "" ], [ "Zeppenfeld", "Dieter", "" ] ]
The next-to-leading order QCD corrections to W gamma production in association with two jets via vector boson fusion are calculated, including the leptonic decay of the W with full off-shell effects and spin correlations. The process lends itself to a test of quartic gauge couplings. The next-to-leading order corrections reduce the scale uncertainty significantly and show a non-trivial phase space dependence.
hep-ph/0412328
Kim Maltman
K. Maltman
Constituent quark models and pentaquark baryons
4 pages. Prepared for the Proceedings of the 1st APS Topical Group on Hadronic Physics (GHP) meeting, FNAL, Oct. 24-26, 2004
J.Phys.Conf.Ser. 9 (2005) 205-208
10.1088/1742-6596/9/1/037
null
hep-ph
null
We discuss certain general features of the pentaquark picture for the theta, its 10bar_F partner, Xi_{3/2}, and possible heavy quark analogues. Models employing spin-dependent interactions based on either effective Goldstone boson exchange or effective color magnetic exchange are also used to shed light on possible corrections to the Jaffe-Wilczek and Karliner-Lipkin scenarios. Some model-dependent features of the pentaquark picture (splitting patterns and relative decay couplings) are also discussed in the context of these models.
[ { "created": "Wed, 22 Dec 2004 04:05:39 GMT", "version": "v1" } ]
2009-11-10
[ [ "Maltman", "K.", "" ] ]
We discuss certain general features of the pentaquark picture for the theta, its 10bar_F partner, Xi_{3/2}, and possible heavy quark analogues. Models employing spin-dependent interactions based on either effective Goldstone boson exchange or effective color magnetic exchange are also used to shed light on possible corrections to the Jaffe-Wilczek and Karliner-Lipkin scenarios. Some model-dependent features of the pentaquark picture (splitting patterns and relative decay couplings) are also discussed in the context of these models.
2104.00046
Tania Robens
Tania Robens, Jan Kalinowski, Aleksander Filip Zarnecki, Andreas Papaefstathiou
Extended scalar sectors at future colliders
20 pages, 8 figures; Presented at XXVII Cracow EPIPHANY Conference of Future of particle physics
null
10.5506/APhysPolB.52.1055
RBI-ThPhys-2021-14
hep-ph
http://creativecommons.org/licenses/by/4.0/
After the discovery of the Higgs boson in 2012, particle physics has entered an exciting era. An important question is whether the Standard Model of particle physics correctly describes the scalar sector realized by nature, or whether it is part of a more extended model, featuring additional particle content. A prime way to test this is to probe models with extended scalar sectors at future collider facilities. We here discuss such models in the context of high-luminosity LHC, a possible proton-proton collider with 27 and 100 TeV center-of-mass energy, as well as future lepton colliders with various center-of-mass energies.
[ { "created": "Wed, 31 Mar 2021 18:15:24 GMT", "version": "v1" } ]
2021-08-04
[ [ "Robens", "Tania", "" ], [ "Kalinowski", "Jan", "" ], [ "Zarnecki", "Aleksander Filip", "" ], [ "Papaefstathiou", "Andreas", "" ] ]
After the discovery of the Higgs boson in 2012, particle physics has entered an exciting era. An important question is whether the Standard Model of particle physics correctly describes the scalar sector realized by nature, or whether it is part of a more extended model, featuring additional particle content. A prime way to test this is to probe models with extended scalar sectors at future collider facilities. We here discuss such models in the context of high-luminosity LHC, a possible proton-proton collider with 27 and 100 TeV center-of-mass energy, as well as future lepton colliders with various center-of-mass energies.
hep-ph/9709499
John Collins
John C. Collins (Penn State)
Proof of Factorization for Diffractive Hard Scattering
Revtex, 12 pages, 8 figures. Two figures corrected
Phys.Rev.D57:3051-3056,1998; Erratum-ibid.D61:019902,2000
10.1103/PhysRevD.57.3051 10.1103/PhysRevD.61.019902
PSU/TH/189
hep-ph
null
A proof is given that hard-scattering factorization is valid for deep-inelastic processes which are diffractive or which have some other condition imposed on the final state in the target fragmentation region.
[ { "created": "Mon, 29 Sep 1997 20:28:43 GMT", "version": "v1" }, { "created": "Wed, 22 Sep 1999 19:07:22 GMT", "version": "v2" } ]
2014-11-17
[ [ "Collins", "John C.", "", "Penn State" ] ]
A proof is given that hard-scattering factorization is valid for deep-inelastic processes which are diffractive or which have some other condition imposed on the final state in the target fragmentation region.
1106.5894
Georgi Dvali
Gia Dvali, Cesar Gomez and Slava Mukhanov
Black Hole Masses are Quantized
23 pages, Latex
null
null
null
hep-ph gr-qc hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give a simple argument showing that in any sensible quantum field theory the masses of black holes cannot assume continuous values and must be quantized. Our proof solely relies on Poincare-invariance of the asymptotic background, and is insensitive to geometric characteristics of black holes or other peculiarities of the short distance physics. Therefore, our results are equally-applicable to any other localized objects on asymptotically Poincare-invariant space, such as classicalons. By adding a requirement that in large mass limit the quantization must approximately account for classical results, we derive an universal quantization rule applicable to all classicalons (including black holes) in arbitrary number of dimensions. In particular, this implies, that black holes cannot emit/absorb arbitrarily soft quanta. The effect has phenomenological model-independent implications for black holes and other classicalons that may be created at LHC. We predict, that contrary to naive intuition, the black holes and/or classicalons, will be produced in form of fully-fledged quantum resonances of discrete masses, with the level-spacing controlled by the inverse square-root of cross-section.
[ { "created": "Wed, 29 Jun 2011 10:04:39 GMT", "version": "v1" } ]
2011-07-07
[ [ "Dvali", "Gia", "" ], [ "Gomez", "Cesar", "" ], [ "Mukhanov", "Slava", "" ] ]
We give a simple argument showing that in any sensible quantum field theory the masses of black holes cannot assume continuous values and must be quantized. Our proof solely relies on Poincare-invariance of the asymptotic background, and is insensitive to geometric characteristics of black holes or other peculiarities of the short distance physics. Therefore, our results are equally-applicable to any other localized objects on asymptotically Poincare-invariant space, such as classicalons. By adding a requirement that in large mass limit the quantization must approximately account for classical results, we derive an universal quantization rule applicable to all classicalons (including black holes) in arbitrary number of dimensions. In particular, this implies, that black holes cannot emit/absorb arbitrarily soft quanta. The effect has phenomenological model-independent implications for black holes and other classicalons that may be created at LHC. We predict, that contrary to naive intuition, the black holes and/or classicalons, will be produced in form of fully-fledged quantum resonances of discrete masses, with the level-spacing controlled by the inverse square-root of cross-section.
1404.3050
Vladimir Korotkikh
V. L. Korotkikh, E. E. Zabrodin
Parton-medium cross section and average QGP viscosity in lead-lead collisions at LHC
12 pages, 1 figure. arXiv admin note: text overlap with arXiv:1204.1409 by other authors
null
10.1088/0954-3899/42/11/115102
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent experimental CMS and E-by-E ATLAS data on the elliptic anisotropy of particles in \PbPb collisions are used to extract parton medium cross-section and the quark-gluon plasma viscosity-to-entropy ratio within the incomplete equilibration medium model. Our method assumes extrapolation of the measured pseudorapidity spectrum of charged particles to low-$p_T$ range. Then the rapidity distribution of both charged and neutral hadrons is restored. The extracted value of the parton-medium cross section is found to be $\ds \sigma = (3.1 \pm 0.2) {\rm mb}$. It yields $\eta/s = 0.17 \pm 0.02$ for the ratio of shear viscosity to entropy density in QGP phase. The last result is in a good agreement with the estimates obtained by calculations within the viscous hydrodynamics.
[ { "created": "Fri, 11 Apr 2014 09:39:00 GMT", "version": "v1" }, { "created": "Wed, 1 Apr 2015 17:10:40 GMT", "version": "v2" } ]
2015-10-28
[ [ "Korotkikh", "V. L.", "" ], [ "Zabrodin", "E. E.", "" ] ]
The recent experimental CMS and E-by-E ATLAS data on the elliptic anisotropy of particles in \PbPb collisions are used to extract parton medium cross-section and the quark-gluon plasma viscosity-to-entropy ratio within the incomplete equilibration medium model. Our method assumes extrapolation of the measured pseudorapidity spectrum of charged particles to low-$p_T$ range. Then the rapidity distribution of both charged and neutral hadrons is restored. The extracted value of the parton-medium cross section is found to be $\ds \sigma = (3.1 \pm 0.2) {\rm mb}$. It yields $\eta/s = 0.17 \pm 0.02$ for the ratio of shear viscosity to entropy density in QGP phase. The last result is in a good agreement with the estimates obtained by calculations within the viscous hydrodynamics.
1004.2497
Oscar Cata
Luigi Cappiello, Oscar Cata and Giancarlo D'Ambrosio
Antisymmetric tensors in holographic approaches to QCD
15 pages, 2 figures. Minor changes to match the journal version
Phys.Rev.D82:095008,2010
10.1103/PhysRevD.82.095008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study real (massive) antisymmetric tensors of rank two in holographic models of QCD based on the gauge/string duality. Our aim is to understand in detail how the AdS/CFT correspondence describes correlators with tensor currents in QCD. To this end we study a set of bootstrapped correlators with spin-1 vector and tensor currents, imposing matching to QCD at the partonic level. We show that a consistent description of this set of correlators yields a very predictive picture. For instance, it imposes strong constraints on infrared boundary conditions and precludes the introduction of dilatonic backgrounds as a mechanism to achieve linear confinement. Additionally, correlators with tensor currents turn out to be especially sensitive to chiral symmetry breaking, thus offering an ideal testing ground for genuine QCD effects. Several phenomenological consequences are explored, such as the nontrivial interplay between $1^{+-}$ states and conventional $1^{--}$ vector mesons.
[ { "created": "Wed, 14 Apr 2010 20:09:51 GMT", "version": "v1" }, { "created": "Wed, 8 Dec 2010 09:52:16 GMT", "version": "v2" } ]
2010-12-23
[ [ "Cappiello", "Luigi", "" ], [ "Cata", "Oscar", "" ], [ "D'Ambrosio", "Giancarlo", "" ] ]
We study real (massive) antisymmetric tensors of rank two in holographic models of QCD based on the gauge/string duality. Our aim is to understand in detail how the AdS/CFT correspondence describes correlators with tensor currents in QCD. To this end we study a set of bootstrapped correlators with spin-1 vector and tensor currents, imposing matching to QCD at the partonic level. We show that a consistent description of this set of correlators yields a very predictive picture. For instance, it imposes strong constraints on infrared boundary conditions and precludes the introduction of dilatonic backgrounds as a mechanism to achieve linear confinement. Additionally, correlators with tensor currents turn out to be especially sensitive to chiral symmetry breaking, thus offering an ideal testing ground for genuine QCD effects. Several phenomenological consequences are explored, such as the nontrivial interplay between $1^{+-}$ states and conventional $1^{--}$ vector mesons.
2404.00089
Nikolaos Kidonakis
Nikolaos Kidonakis and Alberto Tonero
N$^3$LO soft-gluon corrections in single-particle-inclusive kinematics and $H^+ H^-$ production
19 pages, 5 figures, 2 tables; v2 has some additional material and it is the published version
JHEP 06, 138 (2024)
10.1007/JHEP06(2024)138
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the complete soft-gluon corrections for the production of colorless final states through N$^3$LO in single-particle-inclusive kinematics. We present explicit analytical results and use them to study higher-order QCD corrections for the production of a heavy charged Higgs pair ($H^+ H^-$) via quark-antiquark annihilation in the Two-Higgs-Doublet Model at LHC energies. We calculate the NNLO soft-gluon and virtual QCD corrections as well as the N$^3$LO soft-gluon corrections to the total cross section and the charged-Higgs rapidity distribution. This is the first calculation of complete N$^3$LO soft-gluon corrections for a process in single-particle-inclusive kinematics, and the results can be applied to other processes with colorless final states.
[ { "created": "Fri, 29 Mar 2024 18:00:01 GMT", "version": "v1" }, { "created": "Sun, 23 Jun 2024 20:24:57 GMT", "version": "v2" } ]
2024-06-25
[ [ "Kidonakis", "Nikolaos", "" ], [ "Tonero", "Alberto", "" ] ]
We calculate the complete soft-gluon corrections for the production of colorless final states through N$^3$LO in single-particle-inclusive kinematics. We present explicit analytical results and use them to study higher-order QCD corrections for the production of a heavy charged Higgs pair ($H^+ H^-$) via quark-antiquark annihilation in the Two-Higgs-Doublet Model at LHC energies. We calculate the NNLO soft-gluon and virtual QCD corrections as well as the N$^3$LO soft-gluon corrections to the total cross section and the charged-Higgs rapidity distribution. This is the first calculation of complete N$^3$LO soft-gluon corrections for a process in single-particle-inclusive kinematics, and the results can be applied to other processes with colorless final states.
hep-ph/0010002
Nikolaos Kidonakis
Nikolaos Kidonakis
High-order corrections and subleading logarithms for top quark production
32 pages LaTeX, 7 figures; a lot of new material has been added, including an expanded discussion in section 3.3 on resummation prescriptions, and a new appendix; to appear in Phys. Rev. D
Phys.Rev. D64 (2001) 014009
10.1103/PhysRevD.64.014009
FSU-HEP-20000920
hep-ph hep-ex
null
We derive high-order threshold corrections for top quark production in hadronic collisions from resummation calculations. We present analytical expressions for the cross section through next-to-next-to-next-to-next-to-leading order (N^4LO) and next-to-next-to-leading logarithmic accuracy. Special attention is paid to the role of subleading logarithms and how they relate to the convergence of the perturbation series and differences between various resummation prescriptions. It is shown that care must be taken to avoid unphysical terms in the expansions. Numerical results are presented for top quark production at the Tevatron. We find sizeable increases to the total cross section and differential distributions and a dramatic reduction of the factorization scale dependence relative to next-to-leading order.
[ { "created": "Sat, 30 Sep 2000 21:49:37 GMT", "version": "v1" }, { "created": "Wed, 21 Mar 2001 20:48:54 GMT", "version": "v2" } ]
2009-10-31
[ [ "Kidonakis", "Nikolaos", "" ] ]
We derive high-order threshold corrections for top quark production in hadronic collisions from resummation calculations. We present analytical expressions for the cross section through next-to-next-to-next-to-next-to-leading order (N^4LO) and next-to-next-to-leading logarithmic accuracy. Special attention is paid to the role of subleading logarithms and how they relate to the convergence of the perturbation series and differences between various resummation prescriptions. It is shown that care must be taken to avoid unphysical terms in the expansions. Numerical results are presented for top quark production at the Tevatron. We find sizeable increases to the total cross section and differential distributions and a dramatic reduction of the factorization scale dependence relative to next-to-leading order.
hep-ph/0408083
Saurabh D. Rindani
Saurabh D. Rindani
Transverse beam polarization and limits on leptoquark couplings in e+e- --> t tbar
13 pages latex, with 6 figures included. Revised version corrects minor error. Latest version corrects minor errors, to appear in Phys. Lett. B
Phys.Lett. B602 (2004) 97-104
10.1016/j.physletb.2004.09.068
null
hep-ph
null
It is shown that if electron and positron beams at a linear collider are transversely polarized, azimuthal asymmetries of the final-state top quark in e+e- --> t tbar can be used to probe a combination of couplings of left and right chiralities in a scalar leptoquark model. The CP-conserving azimuthal asymmetry would be a sensitive test of the chirality violating couplings. A linear collider operating at sqrt{s}=500 GeV and having transverse polarizations of 80% and 60% respectively for the e- and e+ beams, can put a limit of the order of 0.025 on the product of the left and right chirality leptoquark couplings (in units of the electromagnetic coupling constant), with a leptoquark mass of 1 TeV and for an integrated luminosity of 500 inverse fb. The CP-violating azimuthal asymmetry, which would provide a direct test of CP-violating phases in leptoquark couplings, can be constrained to the same level of accuracy. However, this limit is uninteresting in view of the much better indirect limit from the electric dipole moment of the electron.
[ { "created": "Fri, 6 Aug 2004 07:24:57 GMT", "version": "v1" }, { "created": "Mon, 9 Aug 2004 08:16:02 GMT", "version": "v2" }, { "created": "Tue, 12 Oct 2004 08:29:13 GMT", "version": "v3" } ]
2009-11-10
[ [ "Rindani", "Saurabh D.", "" ] ]
It is shown that if electron and positron beams at a linear collider are transversely polarized, azimuthal asymmetries of the final-state top quark in e+e- --> t tbar can be used to probe a combination of couplings of left and right chiralities in a scalar leptoquark model. The CP-conserving azimuthal asymmetry would be a sensitive test of the chirality violating couplings. A linear collider operating at sqrt{s}=500 GeV and having transverse polarizations of 80% and 60% respectively for the e- and e+ beams, can put a limit of the order of 0.025 on the product of the left and right chirality leptoquark couplings (in units of the electromagnetic coupling constant), with a leptoquark mass of 1 TeV and for an integrated luminosity of 500 inverse fb. The CP-violating azimuthal asymmetry, which would provide a direct test of CP-violating phases in leptoquark couplings, can be constrained to the same level of accuracy. However, this limit is uninteresting in view of the much better indirect limit from the electric dipole moment of the electron.
2003.09985
Meshkat Rajaee
Majid Bahraminasr, Pouya Bakhti and Meshkat Rajaee
Sensitivities to secret neutrino interaction at FASER$\nu$
14 pages, 5 figures
null
10.1088/1361-6471/ac11c2
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the impact of the coupling of neutrinos with a new light neutral gauge boson, $Z^\prime$, with a mass of less than 500 {\rm MeV} in FASER$\nu$ experiment. Scenarios in which a light gauge boson is coupled to neutrinos are motivated within numerous contexts which are designed to explain various anomalies in particle physics and cosmology. This interaction leads to a new decay mode for charged mesons to a light lepton plus neutrino and $Z^{\prime}$, ($\pi^+(K^+)\to e^+ \nu Z^\prime$) followed by the subsequent decay of $Z^\prime$ into the pair of neutrino and anti-neutrino, ($Z^\prime \to \nu\bar{\nu}$). FASER$\nu$, the Forward Search Experiment at the LHC, has the potential to detect collider neutrinos for the first time. In particular, the FASER$\nu$ emulsion detector will provide the opportunity to detect $\tau$-neutrinos and to measure their energies. Using this ability of FASER$\nu$ emulsion detector, we investigate the potential of FASER$\nu$ experiment and the proposed upgraded version of this experiment, FASER2$\nu$, to constrain the coupling of a neutrino with the light gauge boson.
[ { "created": "Sun, 22 Mar 2020 20:17:52 GMT", "version": "v1" }, { "created": "Thu, 17 Jun 2021 04:49:12 GMT", "version": "v2" } ]
2021-09-01
[ [ "Bahraminasr", "Majid", "" ], [ "Bakhti", "Pouya", "" ], [ "Rajaee", "Meshkat", "" ] ]
We study the impact of the coupling of neutrinos with a new light neutral gauge boson, $Z^\prime$, with a mass of less than 500 {\rm MeV} in FASER$\nu$ experiment. Scenarios in which a light gauge boson is coupled to neutrinos are motivated within numerous contexts which are designed to explain various anomalies in particle physics and cosmology. This interaction leads to a new decay mode for charged mesons to a light lepton plus neutrino and $Z^{\prime}$, ($\pi^+(K^+)\to e^+ \nu Z^\prime$) followed by the subsequent decay of $Z^\prime$ into the pair of neutrino and anti-neutrino, ($Z^\prime \to \nu\bar{\nu}$). FASER$\nu$, the Forward Search Experiment at the LHC, has the potential to detect collider neutrinos for the first time. In particular, the FASER$\nu$ emulsion detector will provide the opportunity to detect $\tau$-neutrinos and to measure their energies. Using this ability of FASER$\nu$ emulsion detector, we investigate the potential of FASER$\nu$ experiment and the proposed upgraded version of this experiment, FASER2$\nu$, to constrain the coupling of a neutrino with the light gauge boson.
1011.1439
Baris Altunkaynak
Baris Altunkaynak, Brent D. Nelson, Lisa L. Everett, Yongyan Rao, and Ian-Woo Kim
Landscape of Supersymmetric Particle Mass Hierarchies in Deflected Mirage Mediation
33 pages, 23 figures
Eur. Phys. J. Plus 127 (2012) 2
10.1140/epjp/i2012-12002-6
MADPH-10-1564; MCTP-10-51
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the aim of uncovering viable regions of parameter space in deflected mirage mediation (DMM) models of supersymmetry breaking, we study the landscape of particle mass hierarchies for the lightest four non-Standard Model states for DMM models and compare the results to that of minimal supergravity/constrained MSSM (mSUGRA/CMSSM) models, building on previous studies of Feldman, Liu, and Nath. Deflected mirage mediation is a string-motivated scenario in which the soft terms include comparable contributions from gravity mediation, gauge mediation, and anomaly mediation. DMM allows a wide variety of phenomenologically preferred models with light charginos and neutralinos, including novel patterns in which the heavy Higgs particles are lighter than the lightest superpartner. We use this analysis to motivate two DMM benchmark points to be used for more detailed collider studies. One model point has a higgsino-dominated lightest superpartner and a compressed yet heavy spectrum, while the other has a stau NLSP and similar features to mSUGRA/CMSSM models, but with a slightly less stretched spectrum.
[ { "created": "Fri, 5 Nov 2010 15:59:31 GMT", "version": "v1" }, { "created": "Tue, 1 Nov 2011 22:25:38 GMT", "version": "v2" } ]
2012-01-26
[ [ "Altunkaynak", "Baris", "" ], [ "Nelson", "Brent D.", "" ], [ "Everett", "Lisa L.", "" ], [ "Rao", "Yongyan", "" ], [ "Kim", "Ian-Woo", "" ] ]
With the aim of uncovering viable regions of parameter space in deflected mirage mediation (DMM) models of supersymmetry breaking, we study the landscape of particle mass hierarchies for the lightest four non-Standard Model states for DMM models and compare the results to that of minimal supergravity/constrained MSSM (mSUGRA/CMSSM) models, building on previous studies of Feldman, Liu, and Nath. Deflected mirage mediation is a string-motivated scenario in which the soft terms include comparable contributions from gravity mediation, gauge mediation, and anomaly mediation. DMM allows a wide variety of phenomenologically preferred models with light charginos and neutralinos, including novel patterns in which the heavy Higgs particles are lighter than the lightest superpartner. We use this analysis to motivate two DMM benchmark points to be used for more detailed collider studies. One model point has a higgsino-dominated lightest superpartner and a compressed yet heavy spectrum, while the other has a stau NLSP and similar features to mSUGRA/CMSSM models, but with a slightly less stretched spectrum.
0907.3496
Andrew Spray
Maxim Perelstein and Andrew Spray
Tensor Reggeons from Warped Space at the LHC
28 pages, 4 figures; Added References, expanded section 2.2, corrected typos, replaced figures
JHEP 0910:096,2009
10.1088/1126-6708/2009/10/096
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hierarchy problem can be addressed by extending the four-dimensional space-time to include an extra compact spatial dimension with non-trivial "warped" metric, as first suggested by Randall and Sundrum. If the Randall-Sundrum framework is realized in string theory, the effective value of the string scale in the vicinity of the infrared boundary should be in the TeV domain. The most attractive models of this type embed the Standard Model particles as zero-modes of five-dimensional fields. In such models, Regge excitations of the Standard Model states should appear around the TeV scale. We construct a toy model that describes tensor (spin-2) excitations of the Standard Model gauge bosons, and their on-shell couplings with light matter and gauge fields, within this framework. We use this toy model to predict the phenomenologically important features of the tensor Regge gluon, such as its mass, production cross section at the LHC, and decay patterns.
[ { "created": "Mon, 20 Jul 2009 21:24:45 GMT", "version": "v1" }, { "created": "Thu, 13 Aug 2009 20:33:53 GMT", "version": "v2" }, { "created": "Thu, 15 Oct 2009 20:36:03 GMT", "version": "v3" } ]
2009-11-13
[ [ "Perelstein", "Maxim", "" ], [ "Spray", "Andrew", "" ] ]
The hierarchy problem can be addressed by extending the four-dimensional space-time to include an extra compact spatial dimension with non-trivial "warped" metric, as first suggested by Randall and Sundrum. If the Randall-Sundrum framework is realized in string theory, the effective value of the string scale in the vicinity of the infrared boundary should be in the TeV domain. The most attractive models of this type embed the Standard Model particles as zero-modes of five-dimensional fields. In such models, Regge excitations of the Standard Model states should appear around the TeV scale. We construct a toy model that describes tensor (spin-2) excitations of the Standard Model gauge bosons, and their on-shell couplings with light matter and gauge fields, within this framework. We use this toy model to predict the phenomenologically important features of the tensor Regge gluon, such as its mass, production cross section at the LHC, and decay patterns.
hep-ph/9509215
Renard Fernand Michel
F.M. Renard
Residual New Physics Effects in $e^+e^-$ and $\gamma\gamma$ Collisions
19 pages + 5 figures in ps file. (renard@lpmsun2.lpm.univ-montp2.fr)
null
null
PM/95-31
hep-ph
null
We present a set of studies concerning the description of New Physics (NP) effects caracterized by a scale much higher than the electroweak scale. We show that both present experimental results and several types of theretical considerations about the Standard Model (SM) and NP suggest a hierarchy among the sectors in which NP manifestations should appear. We concentrate on residual effects described by effective lagrangians involving bosonic and/or heavy quark fields. For each operator we propose an unambiguous definition of the NP scale given by the energy at which unitarity is saturated. We also consider the possible existence of Higher Vector Bosons. We then study the tests realizable at present and future colliders. We start from the analysis of the high precision tests at Z peak, discussing separately the constraints obtained from the light fermionic sector and those due to the $b\bar b$ sector. We then consider the process $e^+e^-\to f\bar f$ at higher energies (LEP2 and NLC) and we propose the "Z peak subtracted representation" which allows to automatically take into account Z peak constraints and to describe several types of NP effects at any other energy. Applications to various NP effects (Higher Vector Bosons, Technicolour resonances, Anomalous Gauge Boson couplings) are given. We then concentrate on several bosonic processes, $e^+e^-\to W^+W^-$, $HZ$, $H\gamma$, and $\gamma\gamma$ collisions producing boson pairs or a single Higgs. We study the sensitivities to the various operators involved in the effective lagrangian and we propose ways to disentangle them. The NP scales which can be felt vary from a few TeV at LEP2 up to 200 TeV in single H production at NLC.
[ { "created": "Mon, 4 Sep 1995 10:45:22 GMT", "version": "v1" } ]
2016-09-01
[ [ "Renard", "F. M.", "" ] ]
We present a set of studies concerning the description of New Physics (NP) effects caracterized by a scale much higher than the electroweak scale. We show that both present experimental results and several types of theretical considerations about the Standard Model (SM) and NP suggest a hierarchy among the sectors in which NP manifestations should appear. We concentrate on residual effects described by effective lagrangians involving bosonic and/or heavy quark fields. For each operator we propose an unambiguous definition of the NP scale given by the energy at which unitarity is saturated. We also consider the possible existence of Higher Vector Bosons. We then study the tests realizable at present and future colliders. We start from the analysis of the high precision tests at Z peak, discussing separately the constraints obtained from the light fermionic sector and those due to the $b\bar b$ sector. We then consider the process $e^+e^-\to f\bar f$ at higher energies (LEP2 and NLC) and we propose the "Z peak subtracted representation" which allows to automatically take into account Z peak constraints and to describe several types of NP effects at any other energy. Applications to various NP effects (Higher Vector Bosons, Technicolour resonances, Anomalous Gauge Boson couplings) are given. We then concentrate on several bosonic processes, $e^+e^-\to W^+W^-$, $HZ$, $H\gamma$, and $\gamma\gamma$ collisions producing boson pairs or a single Higgs. We study the sensitivities to the various operators involved in the effective lagrangian and we propose ways to disentangle them. The NP scales which can be felt vary from a few TeV at LEP2 up to 200 TeV in single H production at NLC.
0704.1429
Alexey Gladyshev
A.V.Gladyshev, D.I.Kazakov, M.G.Paucar
Light stops in the MSSM parameter space
10 pages, 10 eps figures
null
null
null
hep-ph
null
We consider the regions of the MSSM parameter space where the top squarks become light and even may be the LSP. This happens when the triple scalar coupling A becomes very big compared to m_0. We show that in this case the requirement that the LSP is neutral imposes noticeable constraint on the parameter space excluding low m_0 and m_{1/2} similar to constraint from the Higgs mass limit. In some cases these constraints overlap. This picture takes place in a wide region of \tan\beta. In a narrow band close to the border line the stops are long-lived particles and decay into quarks and neutralino (chargino). The cross-section of their production at LHC via gluon fusion mechanism in this region may reach a few pb.
[ { "created": "Wed, 11 Apr 2007 14:39:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gladyshev", "A. V.", "" ], [ "Kazakov", "D. I.", "" ], [ "Paucar", "M. G.", "" ] ]
We consider the regions of the MSSM parameter space where the top squarks become light and even may be the LSP. This happens when the triple scalar coupling A becomes very big compared to m_0. We show that in this case the requirement that the LSP is neutral imposes noticeable constraint on the parameter space excluding low m_0 and m_{1/2} similar to constraint from the Higgs mass limit. In some cases these constraints overlap. This picture takes place in a wide region of \tan\beta. In a narrow band close to the border line the stops are long-lived particles and decay into quarks and neutralino (chargino). The cross-section of their production at LHC via gluon fusion mechanism in this region may reach a few pb.
hep-ph/0402055
Jure Zupan
M. Gronau, Y. Grossman, N. Shuhmaher, A. Soffer, J. Zupan
Using untagged B^0 -> D K_S to determine gamma
18 pages, same as published version
Phys.Rev. D69 (2004) 113003
10.1103/PhysRevD.69.113003
null
hep-ph
null
It is shown that the weak phase gamma=arg(-V_{ud}V^*_{ub}V_{cb}V_{cd}^*) can be determined using only untagged decays B/Bbar--> D K_S. In order to reduce the uncertainty in gamma, we suggest combining information from B^{+-}--> DK^{+-} and from untagged B^0 decays, where the D meson is observed in common decay modes. Theoretical assumptions, which may further reduce the statistical error, are also discussed.
[ { "created": "Thu, 5 Feb 2004 15:56:38 GMT", "version": "v1" }, { "created": "Wed, 2 Jun 2004 15:12:39 GMT", "version": "v2" } ]
2009-11-10
[ [ "Gronau", "M.", "" ], [ "Grossman", "Y.", "" ], [ "Shuhmaher", "N.", "" ], [ "Soffer", "A.", "" ], [ "Zupan", "J.", "" ] ]
It is shown that the weak phase gamma=arg(-V_{ud}V^*_{ub}V_{cb}V_{cd}^*) can be determined using only untagged decays B/Bbar--> D K_S. In order to reduce the uncertainty in gamma, we suggest combining information from B^{+-}--> DK^{+-} and from untagged B^0 decays, where the D meson is observed in common decay modes. Theoretical assumptions, which may further reduce the statistical error, are also discussed.
hep-ph/9502244
Christo Christov
T.Watabe, Chr.V.Christov and K.Goeke
$E2/M1$ Ratio for the $\gamma N\rightarrow \Delta$ Transition in the Chiral Quark Soliton Model
11 pages, revtex, a figure included as a postscript file
Phys.Lett. B349 (1995) 197-203
10.1016/0370-2693(95)00227-C
RUB-TP2-1/95
hep-ph
null
We calculate the electric quadrupole to magnetic dipole transition ratio $E2/M1$ for the reaction $\gamma N \ra \Delta(1232)$ in the chiral quark soliton model. The calculated $E2/M1$ ratio is in a good agreement with the very new experimental data. We obtain non-zero negative value for the electric quadrupole $N-\Delta$ transition moment, which suggests an oblate deformed charge structure of the nucleon or/and the delta isobar. Other observables related to this quantity, namely the $N-\Delta$ mass splitting, the isovector charge radius, and isovector magnetic moment, are properly reproduced as well.
[ { "created": "Tue, 7 Feb 1995 15:10:56 GMT", "version": "v1" } ]
2016-09-01
[ [ "Watabe", "T.", "" ], [ "Christov", "Chr. V.", "" ], [ "Goeke", "K.", "" ] ]
We calculate the electric quadrupole to magnetic dipole transition ratio $E2/M1$ for the reaction $\gamma N \ra \Delta(1232)$ in the chiral quark soliton model. The calculated $E2/M1$ ratio is in a good agreement with the very new experimental data. We obtain non-zero negative value for the electric quadrupole $N-\Delta$ transition moment, which suggests an oblate deformed charge structure of the nucleon or/and the delta isobar. Other observables related to this quantity, namely the $N-\Delta$ mass splitting, the isovector charge radius, and isovector magnetic moment, are properly reproduced as well.
2205.07241
Oliver Gould
Andreas Ekstedt, Oliver Gould and Johan L\"ofgren
Radiative first-order phase transitions to next-to-next-to-leading order
7 pages, 3 figures; typo fixed in v3
Phys. Rev. D 106 (2022) 3, 036012
10.1103/PhysRevD.106.036012
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We develop new perturbative tools to accurately study radiatively-induced first-order phase transitions. Previous perturbative methods have suffered internal inconsistencies and been unsuccessful in reproducing lattice data, which is often attributed to infrared divergences of massless modes (the Linde problem). We employ a consistent power counting scheme to perform calculations, and compare our results against lattice data. We conclude that the consistent expansion removes many previous issues, and indicates that the infamous Linde problem is not as big a factor in these calculations as previously thought.
[ { "created": "Sun, 15 May 2022 09:54:03 GMT", "version": "v1" }, { "created": "Sat, 3 Sep 2022 15:14:04 GMT", "version": "v2" }, { "created": "Tue, 11 Jun 2024 11:03:40 GMT", "version": "v3" } ]
2024-06-12
[ [ "Ekstedt", "Andreas", "" ], [ "Gould", "Oliver", "" ], [ "Löfgren", "Johan", "" ] ]
We develop new perturbative tools to accurately study radiatively-induced first-order phase transitions. Previous perturbative methods have suffered internal inconsistencies and been unsuccessful in reproducing lattice data, which is often attributed to infrared divergences of massless modes (the Linde problem). We employ a consistent power counting scheme to perform calculations, and compare our results against lattice data. We conclude that the consistent expansion removes many previous issues, and indicates that the infamous Linde problem is not as big a factor in these calculations as previously thought.
hep-ph/9608323
Nicholas Tracas
G.K. Leontaris and N.D. Tracas
Duality Constraints on Supersymmetric Unified Models and Radiative Symmetry Breaking
LaTex file, 15 pages, 3 figures attached. Misprints in Eqs(28-32) corrected. Shorter version to appear in Physics Letters B
Phys.Lett. B389 (1996) 515-522
10.1016/S0370-2693(96)01299-3
IOA 02/96, NTUA 55-96
hep-ph hep-th
null
Motivated from unified models with string origin, we analyse the constraints from duality invariance on effective supergravity models with an intermediate gauge symmetry. Requiring vanishing vacuum energy and invariance of the superpotential couplings, we find that modular weights of the matter and higgs fields are subject to various constraints. In addition, the vacuum expectation values of the higgs fields breaking the intermediate gauge group, are determined in terms of their modular weights and the moduli. We also examine the possibility of breaking the intermediate gauge symmetry radiatively.
[ { "created": "Wed, 14 Aug 1996 15:41:35 GMT", "version": "v1" }, { "created": "Tue, 20 Aug 1996 15:20:54 GMT", "version": "v2" }, { "created": "Wed, 25 Sep 1996 08:08:56 GMT", "version": "v3" } ]
2009-10-28
[ [ "Leontaris", "G. K.", "" ], [ "Tracas", "N. D.", "" ] ]
Motivated from unified models with string origin, we analyse the constraints from duality invariance on effective supergravity models with an intermediate gauge symmetry. Requiring vanishing vacuum energy and invariance of the superpotential couplings, we find that modular weights of the matter and higgs fields are subject to various constraints. In addition, the vacuum expectation values of the higgs fields breaking the intermediate gauge group, are determined in terms of their modular weights and the moduli. We also examine the possibility of breaking the intermediate gauge symmetry radiatively.
hep-ph/0201082
Cliff Burgess
C.P. Burgess, J. Cline, E. Filotas, J. Matias and G.D. Moore
Loop-Generated Bounds on Changes to the Graviton Dispersion Relation
18 pages, LaTeX, 4 figures, uses revtex
JHEP0203:043,2002
10.1088/1126-6708/2002/03/043
McGill-01/26, UW/PT 01-27
hep-ph gr-qc hep-th
null
We identify the effective theory appropriate to the propagation of massless bulk fields in brane-world scenarios, to show that the dominant low-energy effect of asymmetric warping in the bulk is to modify the dispersion relation of the effective 4-dimensional modes. We show how such changes to the graviton dispersion relation may be bounded through the effects they imply, through loops, for the propagation of standard model particles. We compute these bounds and show that they provide, in some cases, the strongest constraints on nonstandard gravitational dispersions. The bounds obtained in this way are the strongest for the fewest extra dimensions and when the extra-dimensional Planck mass is the smallest. Although the best bounds come for warped 5-D scenarios, for which the 5D Planck Mass is O(TeV), even in 4 dimensions the graviton loop can lead to a bound on the graviton speed which is comparable with other constraints.
[ { "created": "Thu, 10 Jan 2002 21:16:05 GMT", "version": "v1" } ]
2009-11-07
[ [ "Burgess", "C. P.", "" ], [ "Cline", "J.", "" ], [ "Filotas", "E.", "" ], [ "Matias", "J.", "" ], [ "Moore", "G. D.", "" ] ]
We identify the effective theory appropriate to the propagation of massless bulk fields in brane-world scenarios, to show that the dominant low-energy effect of asymmetric warping in the bulk is to modify the dispersion relation of the effective 4-dimensional modes. We show how such changes to the graviton dispersion relation may be bounded through the effects they imply, through loops, for the propagation of standard model particles. We compute these bounds and show that they provide, in some cases, the strongest constraints on nonstandard gravitational dispersions. The bounds obtained in this way are the strongest for the fewest extra dimensions and when the extra-dimensional Planck mass is the smallest. Although the best bounds come for warped 5-D scenarios, for which the 5D Planck Mass is O(TeV), even in 4 dimensions the graviton loop can lead to a bound on the graviton speed which is comparable with other constraints.
1103.2035
Defu Hou
Defu Hou, Hui Liu, and Hai-cang Ren
Some Field Theoretic Issues Regarding the Chiral Magnetic Effect
19 pages, 4 figures in Latex. Typos fixed, version accepted to be published in JHEP
JHEP 1105:046,2011
10.1007/JHEP05(2011)046
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we shall address some field theoretic issues regarding the chiral magnetic effect. The general structure of the magnetic current consistent with the electromagnetic gauge invariance is obtained and the impact of the infrared divergence is examined. Some subtleties on the relation between the chiral magnetic effect and the axial anomaly are clarified through a careful examination of the infrared limit of the relevant thermal diagrams.
[ { "created": "Thu, 10 Mar 2011 13:48:12 GMT", "version": "v1" }, { "created": "Fri, 6 May 2011 14:23:23 GMT", "version": "v2" } ]
2011-05-13
[ [ "Hou", "Defu", "" ], [ "Liu", "Hui", "" ], [ "Ren", "Hai-cang", "" ] ]
In this paper, we shall address some field theoretic issues regarding the chiral magnetic effect. The general structure of the magnetic current consistent with the electromagnetic gauge invariance is obtained and the impact of the infrared divergence is examined. Some subtleties on the relation between the chiral magnetic effect and the axial anomaly are clarified through a careful examination of the infrared limit of the relevant thermal diagrams.
2307.01336
Fabio Dahia
F. Dahia and A.S.Lemos
The alpha particle charge radius, the radion and the proton radius puzzle
null
null
null
null
hep-ph gr-qc physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent measurements of the Lamb shift of muonic helium-4 ions were used to infer the alpha particle charge radius. The value found is compatible with the radius extracted from the analysis of the electron-helium scattering. Thus, the new spectroscopic data put additional empiric bounds on some free parameters of certain physics theories beyond the Standard Model. In this paper, we analyze the new data in the context of large extra-dimensional theories. Specifically, we calculate the influence of the radion, the scalar degree of freedom of the higher-dimensional gravity, on the energy difference between the 2S and 2P levels of this exotic atom. The radion field is related to fluctuations of the volume of the supplementary space, and, in comparison with the tensorial degrees of freedom, it couples to matter in a different way. Moreover, as some stabilization mechanism acts exclusively on the scalar degree of freedom, the tensor and scalar fields should be treated as phenomenologically independent quantities. Based on the spectroscopic data of muonic helium, we find constraints for the effective energy scale of the radion as a function of the alpha particle radius. Then, we discuss the implications of these new constraints on the proton radius puzzle.
[ { "created": "Mon, 3 Jul 2023 20:14:39 GMT", "version": "v1" } ]
2023-07-06
[ [ "Dahia", "F.", "" ], [ "Lemos", "A. S.", "" ] ]
Recent measurements of the Lamb shift of muonic helium-4 ions were used to infer the alpha particle charge radius. The value found is compatible with the radius extracted from the analysis of the electron-helium scattering. Thus, the new spectroscopic data put additional empiric bounds on some free parameters of certain physics theories beyond the Standard Model. In this paper, we analyze the new data in the context of large extra-dimensional theories. Specifically, we calculate the influence of the radion, the scalar degree of freedom of the higher-dimensional gravity, on the energy difference between the 2S and 2P levels of this exotic atom. The radion field is related to fluctuations of the volume of the supplementary space, and, in comparison with the tensorial degrees of freedom, it couples to matter in a different way. Moreover, as some stabilization mechanism acts exclusively on the scalar degree of freedom, the tensor and scalar fields should be treated as phenomenologically independent quantities. Based on the spectroscopic data of muonic helium, we find constraints for the effective energy scale of the radion as a function of the alpha particle radius. Then, we discuss the implications of these new constraints on the proton radius puzzle.
hep-ph/9908291
Muneyuki Ishida
Rukmani Mohanta, Anjan K. Giri, Mohinder P. Khanna (Panjab University), Muneyuki Ishida(TIT) and Shin Ishida(Nihon University)
Weak Radiative Decay Lambda_b to Lambda gamma and Quark-Confined Effects in the Covariant Oscillator Quark Model
8 pages, uses ptptex.sty
Prog.Theor.Phys. 102 (1999) 645-652
10.1143/PTP.102.645
null
hep-ph
null
Motivated by the observation of the decay B to K* gamma by the CLEO collaboration, we have systematically analyzed the weak radiative decay Lambda_b to Lambda gamma, evaluating the confined effects of quarks in the covariant oscillator quark model. This decay process receives both short distance (electromagnetic penguins at the one loop level) the long distance contributions in the quark level. The long distance contributions are analyzed using the vector meson dominance (VMD) method. The estimated branching ratio is found to be 0.23 times 10^-5.
[ { "created": "Sat, 7 Aug 1999 05:24:24 GMT", "version": "v1" } ]
2009-10-31
[ [ "Mohanta", "Rukmani", "", "Panjab\n University" ], [ "Giri", "Anjan K.", "", "Panjab\n University" ], [ "Khanna", "Mohinder P.", "", "Panjab\n University" ], [ "Ishida", "Muneyuki", "", "TIT" ], [ "Ishida", "Shin", "", ...
Motivated by the observation of the decay B to K* gamma by the CLEO collaboration, we have systematically analyzed the weak radiative decay Lambda_b to Lambda gamma, evaluating the confined effects of quarks in the covariant oscillator quark model. This decay process receives both short distance (electromagnetic penguins at the one loop level) the long distance contributions in the quark level. The long distance contributions are analyzed using the vector meson dominance (VMD) method. The estimated branching ratio is found to be 0.23 times 10^-5.
1203.0282
Aleksander Kusina
T. Stavreva, F. I. Olness, I. Schienbein, T. Jezo, A. Kusina, K. Kovarik, J. Y. Yu
Heavy Quark Production in the ACOT Scheme at NNLO and N3LO
18 pages, 25 figures, updated to match journal version
Phys. Rev. D 85, 114014 (2012)
10.1103/PhysRevD.85.114014
LPSC 12-048; SMU-HEP-12-05; KA-TP-09-2012
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the properties of the ACOT scheme for heavy quark production and make use of the \MSbar massless results at NNLO and N3LO for the structure functions F2 and FL in neutral current deep-inelastic scattering to estimate the higher order corrections. For this purpose we decouple the heavy quark mass entering the phase space from the one entering the dynamics of the short distance cross section. We show numerically that the phase space mass is generally more important. Therefore, the dominant heavy quark mass effects at higher orders can be taken into account using the massless Wilson coefficients together with an appropriate slow-rescaling prescription implementing the phase space constraints. Combining the exact ACOT scheme at NLO with these expressions should provide a good approximation to the missing full calculation in the ACOT scheme at NNLO and N3LO.
[ { "created": "Thu, 1 Mar 2012 20:14:13 GMT", "version": "v1" }, { "created": "Thu, 22 Mar 2012 17:14:05 GMT", "version": "v2" }, { "created": "Mon, 11 Jun 2012 15:02:46 GMT", "version": "v3" } ]
2012-06-12
[ [ "Stavreva", "T.", "" ], [ "Olness", "F. I.", "" ], [ "Schienbein", "I.", "" ], [ "Jezo", "T.", "" ], [ "Kusina", "A.", "" ], [ "Kovarik", "K.", "" ], [ "Yu", "J. Y.", "" ] ]
We analyze the properties of the ACOT scheme for heavy quark production and make use of the \MSbar massless results at NNLO and N3LO for the structure functions F2 and FL in neutral current deep-inelastic scattering to estimate the higher order corrections. For this purpose we decouple the heavy quark mass entering the phase space from the one entering the dynamics of the short distance cross section. We show numerically that the phase space mass is generally more important. Therefore, the dominant heavy quark mass effects at higher orders can be taken into account using the massless Wilson coefficients together with an appropriate slow-rescaling prescription implementing the phase space constraints. Combining the exact ACOT scheme at NLO with these expressions should provide a good approximation to the missing full calculation in the ACOT scheme at NNLO and N3LO.
hep-ph/9212294
null
Jizhi Wu and Richard Arnowitt
Very Large Intermediate Breaking Scale In The Gepner Three Generation Model
19 pages, Plain Tex (Three Figures not included)
Nucl.Phys.B421:125-134,1994
10.1016/0550-3213(94)90227-5
CTP-TAMU-32/91
hep-ph hep-th
null
A detailed study of the intermediate symmetry breaking scale, via the renormalization group equations, for a three generation heterotic string model arising from the N=2 superconformal construction is reported. The numerical study shows that the model admits a very large intermediate breaking scale $\op{>}{\sim}1.0\times10^{16}$ GeV. The role of the gauge singlets in this model is studied, and it is found that these fields play a crucial role in determining the directions and the scale of the intermediate symmetry breaking. The importance of the mixing in generation space is also studied. The generation mixing terms are found to have special effects in the intermediate symmetry breaking. Remarkably these terms can produce some {\it new} Yukawa couplings (not present at the Planck scale) through loops. These couplings are in general very small compared to the ones with non-vanishing tree level values and thus offer a {\it new} mechanism to solve the lepton/quark mass hierarchy problem.
[ { "created": "Mon, 21 Dec 1992 20:33:46 GMT", "version": "v1" } ]
2008-11-26
[ [ "Wu", "Jizhi", "" ], [ "Arnowitt", "Richard", "" ] ]
A detailed study of the intermediate symmetry breaking scale, via the renormalization group equations, for a three generation heterotic string model arising from the N=2 superconformal construction is reported. The numerical study shows that the model admits a very large intermediate breaking scale $\op{>}{\sim}1.0\times10^{16}$ GeV. The role of the gauge singlets in this model is studied, and it is found that these fields play a crucial role in determining the directions and the scale of the intermediate symmetry breaking. The importance of the mixing in generation space is also studied. The generation mixing terms are found to have special effects in the intermediate symmetry breaking. Remarkably these terms can produce some {\it new} Yukawa couplings (not present at the Planck scale) through loops. These couplings are in general very small compared to the ones with non-vanishing tree level values and thus offer a {\it new} mechanism to solve the lepton/quark mass hierarchy problem.
1908.08949
Jesse Thaler
Annie Y. Wei, Preksha Naik, Aram W. Harrow, Jesse Thaler
Quantum Algorithms for Jet Clustering
21 pages, 1 table, 6 figures. v2: correction to doubling trick and additional discussion of resource requirements; approximate version to appear in PRD
Phys. Rev. D 101, 094015 (2020)
10.1103/PhysRevD.101.094015
MIT-CTP 5137
hep-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Identifying jets formed in high-energy particle collisions requires solving optimization problems over potentially large numbers of final-state particles. In this work, we consider the possibility of using quantum computers to speed up jet clustering algorithms. Focusing on the case of electron-positron collisions, we consider a well-known event shape called thrust whose optimum corresponds to the most jet-like separating plane among a set of particles, thereby defining two hemisphere jets. We show how to formulate thrust both as a quantum annealing problem and as a Grover search problem. A key component of our analysis is the consideration of realistic models for interfacing classical data with a quantum algorithm. With a sequential computing model, we show how to speed up the well-known O(N^3) classical algorithm to an O(N^2) quantum algorithm, including the O(N) overhead of loading classical data from N final-state particles. Along the way, we also identify a way to speed up the classical algorithm to O(N^2 log N) using a sorting strategy inspired by the SISCone jet algorithm, which has no natural quantum counterpart. With a parallel computing model, we achieve O(N log N) scaling in both the classical and quantum cases. Finally, we consider the generalization of these quantum methods to other jet algorithms more closely related to those used for proton-proton collisions at the Large Hadron Collider.
[ { "created": "Fri, 23 Aug 2019 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 5 May 2020 23:06:05 GMT", "version": "v2" } ]
2020-05-20
[ [ "Wei", "Annie Y.", "" ], [ "Naik", "Preksha", "" ], [ "Harrow", "Aram W.", "" ], [ "Thaler", "Jesse", "" ] ]
Identifying jets formed in high-energy particle collisions requires solving optimization problems over potentially large numbers of final-state particles. In this work, we consider the possibility of using quantum computers to speed up jet clustering algorithms. Focusing on the case of electron-positron collisions, we consider a well-known event shape called thrust whose optimum corresponds to the most jet-like separating plane among a set of particles, thereby defining two hemisphere jets. We show how to formulate thrust both as a quantum annealing problem and as a Grover search problem. A key component of our analysis is the consideration of realistic models for interfacing classical data with a quantum algorithm. With a sequential computing model, we show how to speed up the well-known O(N^3) classical algorithm to an O(N^2) quantum algorithm, including the O(N) overhead of loading classical data from N final-state particles. Along the way, we also identify a way to speed up the classical algorithm to O(N^2 log N) using a sorting strategy inspired by the SISCone jet algorithm, which has no natural quantum counterpart. With a parallel computing model, we achieve O(N log N) scaling in both the classical and quantum cases. Finally, we consider the generalization of these quantum methods to other jet algorithms more closely related to those used for proton-proton collisions at the Large Hadron Collider.
1704.04523
Ulrich Nierste
Ulrich Nierste and Stefan Schacht
CP asymmetries in $D\to PP^\prime$ decays
Talk at ICHEP2016, 3-10 August 2016, Chicago, USA, and CKM2016, 28 November - 3 December 2016, Tata Institute for Fundamental Research (TIFR), Mumbai, India
null
null
TTP17-019
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This talk addresses two topics related to CP asymmetries in $D$ meson decays to two pseudoscalar mesons. First I discuss how new physics can be distinguished from the Standard Model through two sum rules relating three direct CP asymmetries each, using the sum rule correlating $D^0\to K^+K^-$, $D^0\to \pi^+ \pi^-$, and $D^0\to \pi^0 \pi^0$ for illustration. The other sum rule involves $a_{CP}^{\mathrm{dir}}(D^+\rightarrow \bar{K}^0K^+)$, $a_{CP}^{\mathrm{dir}}(D_s^+\rightarrow K^0\pi^+)$, and $a_{CP}^{\mathrm{dir}}(D_s^+\to K^+ \pi^0)$. The second topic is the direct CP asymmetry in the decay $D^0 \to K_S K_S$, which is expected to be large in the Standard Model for two reasons: Flavor-SU(3) symmetry suppresses the tree amplitude which enhances the crucial "penguin-to-tree" ratio and the "penguin" amplitude is dominated by the tree-level $W$ boson exchange between $c$ and $u$ quarks. We find that $|a_{CP}^{\mathrm{dir}} (D^0 \to K_S K_S)|$ can be as large as $1.1 \%$ in the Standard Model. We advocate $D^0 \to K_S K_S$ as a discovery channel for charm CP violation.
[ { "created": "Fri, 14 Apr 2017 19:49:23 GMT", "version": "v1" } ]
2017-04-18
[ [ "Nierste", "Ulrich", "" ], [ "Schacht", "Stefan", "" ] ]
This talk addresses two topics related to CP asymmetries in $D$ meson decays to two pseudoscalar mesons. First I discuss how new physics can be distinguished from the Standard Model through two sum rules relating three direct CP asymmetries each, using the sum rule correlating $D^0\to K^+K^-$, $D^0\to \pi^+ \pi^-$, and $D^0\to \pi^0 \pi^0$ for illustration. The other sum rule involves $a_{CP}^{\mathrm{dir}}(D^+\rightarrow \bar{K}^0K^+)$, $a_{CP}^{\mathrm{dir}}(D_s^+\rightarrow K^0\pi^+)$, and $a_{CP}^{\mathrm{dir}}(D_s^+\to K^+ \pi^0)$. The second topic is the direct CP asymmetry in the decay $D^0 \to K_S K_S$, which is expected to be large in the Standard Model for two reasons: Flavor-SU(3) symmetry suppresses the tree amplitude which enhances the crucial "penguin-to-tree" ratio and the "penguin" amplitude is dominated by the tree-level $W$ boson exchange between $c$ and $u$ quarks. We find that $|a_{CP}^{\mathrm{dir}} (D^0 \to K_S K_S)|$ can be as large as $1.1 \%$ in the Standard Model. We advocate $D^0 \to K_S K_S$ as a discovery channel for charm CP violation.
1810.09388
Mark Goodsell
Johannes Braathen, Mark D. Goodsell and Pietro Slavich
Matching renormalisable couplings: simple schemes and a plot
59 pages, 7 figures. v2: added some explanations. Matches published version
null
10.1140/epjc/s10052-019-7093-9
OU-HET-984
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss different choices that can be made when matching a general high-energy theory -- with the restriction that it should not contain heavy gauge bosons -- onto a general renormalisable effective field theory at one loop, with particular attention to the quartic scalar couplings and Yukawa couplings. This includes a generalisation of the counterterm scheme that was found to be useful in the case of high-scale/split supersymmetry, but we show the important differences when there are new heavy scalar fields in singlet or triplet representations of $SU(2)$. We also analytically compare our methods and choices with the approach of matching pole masses, proving the equivalence with one of our choices. We outline how to make the extraction of quartic couplings using pole masses more efficient, an approach that we hope will generalise beyond one loop. We give examples of the impact of different scheme choices in a toy model; we also discuss the MSSM and give the threshold corrections to the Higgs quartic coupling in Dirac gaugino models.
[ { "created": "Mon, 22 Oct 2018 16:15:37 GMT", "version": "v1" }, { "created": "Fri, 20 Sep 2019 09:12:56 GMT", "version": "v2" } ]
2019-09-23
[ [ "Braathen", "Johannes", "" ], [ "Goodsell", "Mark D.", "" ], [ "Slavich", "Pietro", "" ] ]
We discuss different choices that can be made when matching a general high-energy theory -- with the restriction that it should not contain heavy gauge bosons -- onto a general renormalisable effective field theory at one loop, with particular attention to the quartic scalar couplings and Yukawa couplings. This includes a generalisation of the counterterm scheme that was found to be useful in the case of high-scale/split supersymmetry, but we show the important differences when there are new heavy scalar fields in singlet or triplet representations of $SU(2)$. We also analytically compare our methods and choices with the approach of matching pole masses, proving the equivalence with one of our choices. We outline how to make the extraction of quartic couplings using pole masses more efficient, an approach that we hope will generalise beyond one loop. We give examples of the impact of different scheme choices in a toy model; we also discuss the MSSM and give the threshold corrections to the Higgs quartic coupling in Dirac gaugino models.
1009.0947
Joachim Brod
Joachim Brod, Martin Gorbahn and Emmanuel Stamou
Two-Loop Electroweak Corrections for the K -> pi nu anti-nu Decays
20 pages, 6 figures; typos corrected, updated numerics using input from PDG 2010, version as published in PRD
Phys.Rev.D83:034030,2011
10.1103/PhysRevD.83.034030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The rare K -> pi nu anti-nu decays play a central role in testing the Standard Model and its extensions. Upcoming experiments plan to measure the decay rates with high accuracy. Yet, unknown higher-order electroweak corrections result in a sizeable theory error. We remove this uncertainty by computing the full two-loop electroweak corrections to the top-quark contribution X_t to the rare decays K_L -> pi0 nu anti-nu, K+ -> pi+ nu anti-nu, and B -> X_{d,s} nu anti-nu in the Standard Model. The remaining theoretical uncertainty related to electroweak effects is now far below 1%. Finally we update the branching ratios to find Br(K_L -> pi0 nu anti-nu) = 2.43(39)(6) * 10^-11 and Br(K+ -> pi+ nu anti-nu) = 7.81(75)(29) * 10^-11. The first error summarises the parametric, the second the remaining theoretical uncertainties.
[ { "created": "Sun, 5 Sep 2010 20:39:14 GMT", "version": "v1" }, { "created": "Tue, 1 Mar 2011 13:33:47 GMT", "version": "v2" } ]
2011-03-02
[ [ "Brod", "Joachim", "" ], [ "Gorbahn", "Martin", "" ], [ "Stamou", "Emmanuel", "" ] ]
The rare K -> pi nu anti-nu decays play a central role in testing the Standard Model and its extensions. Upcoming experiments plan to measure the decay rates with high accuracy. Yet, unknown higher-order electroweak corrections result in a sizeable theory error. We remove this uncertainty by computing the full two-loop electroweak corrections to the top-quark contribution X_t to the rare decays K_L -> pi0 nu anti-nu, K+ -> pi+ nu anti-nu, and B -> X_{d,s} nu anti-nu in the Standard Model. The remaining theoretical uncertainty related to electroweak effects is now far below 1%. Finally we update the branching ratios to find Br(K_L -> pi0 nu anti-nu) = 2.43(39)(6) * 10^-11 and Br(K+ -> pi+ nu anti-nu) = 7.81(75)(29) * 10^-11. The first error summarises the parametric, the second the remaining theoretical uncertainties.
hep-ph/9608248
null
Jun Cao and Hui-fang Wu
Deuteron Electromagnetic Form Factors in the Intermediate Energy Region
9 pages, to appear in Phys.Rev.C
Phys.Rev.C54:1006-1009,1996
10.1103/PhysRevC.54.1006
IHEP-TH-95-34
hep-ph nucl-th
null
Based on a Perturbative QCD analysis of the deuteron form factor, a model for the reduced form factor is suggested. The numerical result is consistent with the data in the intermediate energy region.
[ { "created": "Wed, 7 Aug 1996 22:28:02 GMT", "version": "v1" } ]
2008-11-26
[ [ "Cao", "Jun", "" ], [ "Wu", "Hui-fang", "" ] ]
Based on a Perturbative QCD analysis of the deuteron form factor, a model for the reduced form factor is suggested. The numerical result is consistent with the data in the intermediate energy region.
hep-ph/0008337
Felipe J. Llanes-Estrada
Felipe J. Llanes-Estrada and Stephen R. Cotanch
Many-Body Coulomb Gauge Exotic and Charmed Hybrids
12 pages including 3 figures
Phys.Lett. B504 (2001) 15-20
10.1016/S0370-2693(01)00290-8
null
hep-ph
null
Utilizing a QCD Coulomb gauge Hamiltonian with linear confinement specified by lattice, we report a relativistic many-body calculation for the light exotic and charmed hybrid mesons. The Hamiltonian successfully describes both quark and gluon sectors, with vacuum and quasiparticle properties generated by a BCS transformation and more elaborate TDA and RPA diagonalizations for the meson ($q\bar{q}$) and glueball ($gg$) masses. Hybrids entail a computationally intense relativistic three quasiparticle ($q\bar{q}g$) calculation with the 9 dimensional Hamiltonian matrix elements evaluated variationally by Monte Carlo techniques. Our new TDA (RPA) spectrum for the nonexotic $1^{--}$ charmed ($c\bar{c}$ and $c\bar{c}g$) system provides an explanation for the overpopulation of the observed $J/\psi$ states. For the important $1^{-+}$ light exotic channel we obtain hybrid masses above 2 $GeV$, in broad agreement with lattice and flux tube models, indicating that the recently observed resonances at 1.4 and 1.6 $GeV$ are of different, perhaps four quark, structure.
[ { "created": "Thu, 31 Aug 2000 20:37:50 GMT", "version": "v1" }, { "created": "Wed, 25 Oct 2000 13:35:26 GMT", "version": "v2" } ]
2009-10-31
[ [ "Llanes-Estrada", "Felipe J.", "" ], [ "Cotanch", "Stephen R.", "" ] ]
Utilizing a QCD Coulomb gauge Hamiltonian with linear confinement specified by lattice, we report a relativistic many-body calculation for the light exotic and charmed hybrid mesons. The Hamiltonian successfully describes both quark and gluon sectors, with vacuum and quasiparticle properties generated by a BCS transformation and more elaborate TDA and RPA diagonalizations for the meson ($q\bar{q}$) and glueball ($gg$) masses. Hybrids entail a computationally intense relativistic three quasiparticle ($q\bar{q}g$) calculation with the 9 dimensional Hamiltonian matrix elements evaluated variationally by Monte Carlo techniques. Our new TDA (RPA) spectrum for the nonexotic $1^{--}$ charmed ($c\bar{c}$ and $c\bar{c}g$) system provides an explanation for the overpopulation of the observed $J/\psi$ states. For the important $1^{-+}$ light exotic channel we obtain hybrid masses above 2 $GeV$, in broad agreement with lattice and flux tube models, indicating that the recently observed resonances at 1.4 and 1.6 $GeV$ are of different, perhaps four quark, structure.
1403.1945
Mohamed Mohamed
M. Abu-Shady and A. K. Abu-Nab
Nucleon Properties at Finite Temperature in the Extended Quark-Sigma Model
6 pages, 6 figures The misprints are corrected in the last published version
American Journal of Physics and Applications. Vol. 2, No. 2, 2014, pp. 46-51
10.11648/j.ajpa.20140202.11
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
Hadron properties are studied at hot medium using the quark sigma model. The quark sigma model is extended to include eighth-order of mesonic interactions based on some aspects of quantum chromodynamic (QCD) theory. The extended effective potential tends to the original effective potential when the coupling between the higher order mesonic interactions equal to zero. The field equations have been solved in the mean-field approximation by using the extended iteration method. We found that the nucleon mass increases with increasing temperature and the magnetic moments of proton and neutron increase with increasing temperature. A comparison is presented with recent previous works and other models. We conclude that higher-order mesonic interactions play an important role in changing the behavior of nucleon properties at finite temperature. In addition, the deconfinement phase transition is satisfied in the present model.
[ { "created": "Sat, 8 Mar 2014 07:37:22 GMT", "version": "v1" }, { "created": "Fri, 2 Jan 2015 15:59:45 GMT", "version": "v2" } ]
2015-01-05
[ [ "Abu-Shady", "M.", "" ], [ "Abu-Nab", "A. K.", "" ] ]
Hadron properties are studied at hot medium using the quark sigma model. The quark sigma model is extended to include eighth-order of mesonic interactions based on some aspects of quantum chromodynamic (QCD) theory. The extended effective potential tends to the original effective potential when the coupling between the higher order mesonic interactions equal to zero. The field equations have been solved in the mean-field approximation by using the extended iteration method. We found that the nucleon mass increases with increasing temperature and the magnetic moments of proton and neutron increase with increasing temperature. A comparison is presented with recent previous works and other models. We conclude that higher-order mesonic interactions play an important role in changing the behavior of nucleon properties at finite temperature. In addition, the deconfinement phase transition is satisfied in the present model.
2008.07051
Mauro Napsuciale
M. Napsuciale, S. Rodr\'iguez, H. Hern\'andez-Arellano
Kinetic mixing, custodial symmetry and a lower bound on the dark $Z^{\prime}$ mass
9 pages, notation changed to harmonize it with the PDG one, radiative corrections by SM particles explicitly included
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we consider the extension of the standard model by dark fields with an Abelian $U(1)_{d}$ spontaneously broken gauge symmetry in a hidden dark matter scenario. Considering all the dimension four gauge invariant terms we show that the tree-level relation $M^{2}_{W}=M^{2}_{\tilde Z} \cos^{2} \tilde \theta_{w}$ holds and permits to write the mixing angle induced by the kinetic mixing in the neutral massive gauge boson sector, $\theta_{\zeta}$, in terms of the values of $M_{Z}$, the weak mixing angle and of the mass of the physical dark gauge $Z^{\prime}$ boson. At the loop level, a similar relation is obtained in the $\overline{MS}$ scheme. Using the result extracted from the global fit to electroweak precision data for the ratio $\rho_{0}=M^{2}_{W}/\hat{c}^{2}_{Z} M^{2}_{Z}\hat{\rho}$, we obtain a lower bound $M_{Z^{\prime}}> M_{Z}$ for the dark $Z^{\prime}$ mass at the $94\%$ confidence level. We argue that this lower bound holds in the general case of theories for physics beyond the standard model with an extra $U(1)$ gauge factor subgroup, whenever the extended Higgs potential respects custodial symmetry.
[ { "created": "Mon, 17 Aug 2020 01:33:12 GMT", "version": "v1" }, { "created": "Mon, 18 Oct 2021 10:56:38 GMT", "version": "v2" } ]
2021-10-19
[ [ "Napsuciale", "M.", "" ], [ "Rodríguez", "S.", "" ], [ "Hernández-Arellano", "H.", "" ] ]
In this work we consider the extension of the standard model by dark fields with an Abelian $U(1)_{d}$ spontaneously broken gauge symmetry in a hidden dark matter scenario. Considering all the dimension four gauge invariant terms we show that the tree-level relation $M^{2}_{W}=M^{2}_{\tilde Z} \cos^{2} \tilde \theta_{w}$ holds and permits to write the mixing angle induced by the kinetic mixing in the neutral massive gauge boson sector, $\theta_{\zeta}$, in terms of the values of $M_{Z}$, the weak mixing angle and of the mass of the physical dark gauge $Z^{\prime}$ boson. At the loop level, a similar relation is obtained in the $\overline{MS}$ scheme. Using the result extracted from the global fit to electroweak precision data for the ratio $\rho_{0}=M^{2}_{W}/\hat{c}^{2}_{Z} M^{2}_{Z}\hat{\rho}$, we obtain a lower bound $M_{Z^{\prime}}> M_{Z}$ for the dark $Z^{\prime}$ mass at the $94\%$ confidence level. We argue that this lower bound holds in the general case of theories for physics beyond the standard model with an extra $U(1)$ gauge factor subgroup, whenever the extended Higgs potential respects custodial symmetry.
0812.0265
Ekaterina Christova
Ekaterina Christova, Helmut Eberl and Elena Ginina
CP violation in charged Higgs boson decays
a talk presented at the workshop "Prospects for Charged Higgs Discovery at Colliders", September 16-19 2008, Uppsala Universtity, Sweden, 6 pages with 3 figures. to appear in the Proceedings of the workshop
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
CP violation in H^\pm decays into the three possible decay modes into ordinary particles, 1) H^\pm \to tb, 2) H^\pm \to \nu \tau and 3) H^\pm \to W^\pm h^0 is considered. Analytic expressions and numerical results for the CP violating decay rate asymmetries in the MSSM are obtained. Increasing \tan\beta the asymmetries for the fermionic decays, H^\pm \to tb and H^\pm \to \nu \tau, decrease and it increases for H^\pm \to W^\pm h^0. The asymmetry of H^\pm \to tb is most sensitive to the phase of $A_t and can go up to 20%, the asymmetries of 2) and 3) depend mainly on the phases of A_\tau and M_1. The asymmetry of 2) is smaller than 0.5% and of 3) can reach up to 2%.
[ { "created": "Mon, 1 Dec 2008 10:55:03 GMT", "version": "v1" } ]
2009-04-14
[ [ "Christova", "Ekaterina", "" ], [ "Eberl", "Helmut", "" ], [ "Ginina", "Elena", "" ] ]
CP violation in H^\pm decays into the three possible decay modes into ordinary particles, 1) H^\pm \to tb, 2) H^\pm \to \nu \tau and 3) H^\pm \to W^\pm h^0 is considered. Analytic expressions and numerical results for the CP violating decay rate asymmetries in the MSSM are obtained. Increasing \tan\beta the asymmetries for the fermionic decays, H^\pm \to tb and H^\pm \to \nu \tau, decrease and it increases for H^\pm \to W^\pm h^0. The asymmetry of H^\pm \to tb is most sensitive to the phase of $A_t and can go up to 20%, the asymmetries of 2) and 3) depend mainly on the phases of A_\tau and M_1. The asymmetry of 2) is smaller than 0.5% and of 3) can reach up to 2%.
2111.12469
Nikolaos Stefanis
Sergey Mikhailov, Alexandr Pimikov, N. G. Stefanis
Improved calculation of the $\gamma^*\gamma \rightarrow \pi$ process at low $Q^2$ using LCSR's and renormalization-group summation
8 pages, 3 figures. Work dedicated to the memory of Maxim Polyakov, a deeply admired colleague and friend of ours. Presented at Virtual Tribute to Quark Confinement and the Hadron Spectrum, August 2nd-6th, 2021
null
10.1051/epjconf/202225803003
RUB-TPII-03/2021
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study two versions of lightcone sum rules to calculate the $\gamma^*\gamma\rightarrow\pi^0$ transition form factor (TFF) within QCD. While the standard version is based on fixed-order perturbation theory by means of a power-series expansion in the strong coupling, the new method incorporates radiative corrections by renormalization-group summation and generates an expansion within a generalized fractional analytic perturbation theory involving only analytic couplings. Using this scheme, we determine the relative nonperturbative parameters and the first two Gegenbauer coefficients of the pion distribution amplitude (DA) to obtain TFF predictions in good agreement with the preliminary BESIII data, while the best-fit pion DA satisfies the most recent lattice constraints on the second moment of the pion DA at the three-loop level.
[ { "created": "Wed, 24 Nov 2021 12:44:18 GMT", "version": "v1" } ]
2022-02-16
[ [ "Mikhailov", "Sergey", "" ], [ "Pimikov", "Alexandr", "" ], [ "Stefanis", "N. G.", "" ] ]
We study two versions of lightcone sum rules to calculate the $\gamma^*\gamma\rightarrow\pi^0$ transition form factor (TFF) within QCD. While the standard version is based on fixed-order perturbation theory by means of a power-series expansion in the strong coupling, the new method incorporates radiative corrections by renormalization-group summation and generates an expansion within a generalized fractional analytic perturbation theory involving only analytic couplings. Using this scheme, we determine the relative nonperturbative parameters and the first two Gegenbauer coefficients of the pion distribution amplitude (DA) to obtain TFF predictions in good agreement with the preliminary BESIII data, while the best-fit pion DA satisfies the most recent lattice constraints on the second moment of the pion DA at the three-loop level.
1309.7256
Xin Liu
Xin Liu, Zhen-Jun Xiao, and Zhi-Tian Zou
Branching Ratios and CP Violations of B \to K_0^*(1430) K^* Decays in the pQCD Approach
revtex file, 14 pages, 1 figure, contents improved and typos corrected. Accepted for publication in Phys.Rev.D
null
10.1103/PhysRevD.88.094003
JSNU/PHY-TH-2013
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate $B \to K_0^*(1430) K^*$ decays in the perturbative QCD(pQCD) factorization approach, where $B$ denotes $B_u$, $B_d$ and $B_s$ meson respectively, and the scalar $K_0^*(1430)$ is considered as a meson based on the model of conventional two-quark structure. With the light-cone distribution amplitude of $K_0^*(1430)$ defined in two scenarios, namely Scenario 1 and Scenario 2, we make the first estimation for the branching ratios and CP-violating asymmetries for those concerned decay modes in the pQCD factorization approach. For all considered $B \to K_0^*(1430) K^*$ decays in this paper, only one preliminary upper limit on the branching ratio of $B^0 \to {K_0^*(1430)}^0 \bar{K}^{*0}$ measured at 90% C.L. by Belle Collaboration is available now. It is therefore of great interest to examine the predicted physical quantities at two $B$ factories, Large Hadron Collider experiments, and forthcoming Super-$B$ facility, then test the reliability of the pQCD approach employed to study the considered decay modes involving a $p$-wave scalar meson as one of the final state mesons. Furthermore, these pQCD predictions combined with the future precision measurements are also helpful to explore the complicated QCD dynamics involved in the light scalars.
[ { "created": "Fri, 27 Sep 2013 14:57:28 GMT", "version": "v1" }, { "created": "Thu, 31 Oct 2013 02:13:44 GMT", "version": "v2" } ]
2015-06-17
[ [ "Liu", "Xin", "" ], [ "Xiao", "Zhen-Jun", "" ], [ "Zou", "Zhi-Tian", "" ] ]
We investigate $B \to K_0^*(1430) K^*$ decays in the perturbative QCD(pQCD) factorization approach, where $B$ denotes $B_u$, $B_d$ and $B_s$ meson respectively, and the scalar $K_0^*(1430)$ is considered as a meson based on the model of conventional two-quark structure. With the light-cone distribution amplitude of $K_0^*(1430)$ defined in two scenarios, namely Scenario 1 and Scenario 2, we make the first estimation for the branching ratios and CP-violating asymmetries for those concerned decay modes in the pQCD factorization approach. For all considered $B \to K_0^*(1430) K^*$ decays in this paper, only one preliminary upper limit on the branching ratio of $B^0 \to {K_0^*(1430)}^0 \bar{K}^{*0}$ measured at 90% C.L. by Belle Collaboration is available now. It is therefore of great interest to examine the predicted physical quantities at two $B$ factories, Large Hadron Collider experiments, and forthcoming Super-$B$ facility, then test the reliability of the pQCD approach employed to study the considered decay modes involving a $p$-wave scalar meson as one of the final state mesons. Furthermore, these pQCD predictions combined with the future precision measurements are also helpful to explore the complicated QCD dynamics involved in the light scalars.
1305.1601
Takashi Toma
Takashi Toma
Gamma-rays Constraint on Higgs Production from Dark Matter Annihilation
4 pages, 3 figures, Proceeding for the Toyama International Workshop "Higgs as a Probe of New Physics 2013 (HPNP2013)", 13-16 February 2013
null
null
IPPP/13/27, DCPT/13/54
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A gamma line signal in cosmic-ray observation would be found when Higgs is produced at rest or almost rest by DM annihilation because of decay of 126 GeV Higgs into two gamma. This line signal gives a constraint on Higgs production cross section by DM. We examine this point with simple analysis in this work.
[ { "created": "Tue, 7 May 2013 18:20:13 GMT", "version": "v1" } ]
2013-05-08
[ [ "Toma", "Takashi", "" ] ]
A gamma line signal in cosmic-ray observation would be found when Higgs is produced at rest or almost rest by DM annihilation because of decay of 126 GeV Higgs into two gamma. This line signal gives a constraint on Higgs production cross section by DM. We examine this point with simple analysis in this work.
hep-ph/0410401
Roberto Casalbuoni
R.Casalbuoni, R.Gatto, M.Mannarelli, G.Nardulli and M.Ruggieri
Meissner masses in the gCFL phase of QCD
New Fig. 1 shows that also the masses of the gluons 3 and 8 are imaginary
Phys.Lett.B605:362-368,2005; Erratum-ibid.B615:297,2005
10.1016/j.physletb.2004.11.045 10.1016/j.physletb.2005.04.025
BARI-TH 498/04
hep-ph
null
We calculate the Meissner masses of gluons in neutral three-flavor color superconducting matter for finite strange quark mass. In the CFL phase the eissner masses are slowly varying function of the strange quark mass. For large strange quark mass, in the so called gCFL phase, the Meissner masses of gluons with colors $a=1,2,3$ and 8 become imaginary, indicating an instability.
[ { "created": "Fri, 29 Oct 2004 10:19:51 GMT", "version": "v1" }, { "created": "Thu, 18 Nov 2004 16:27:10 GMT", "version": "v2" }, { "created": "Mon, 11 Apr 2005 12:33:20 GMT", "version": "v3" } ]
2010-11-05
[ [ "Casalbuoni", "R.", "" ], [ "Gatto", "R.", "" ], [ "Mannarelli", "M.", "" ], [ "Nardulli", "G.", "" ], [ "Ruggieri", "M.", "" ] ]
We calculate the Meissner masses of gluons in neutral three-flavor color superconducting matter for finite strange quark mass. In the CFL phase the eissner masses are slowly varying function of the strange quark mass. For large strange quark mass, in the so called gCFL phase, the Meissner masses of gluons with colors $a=1,2,3$ and 8 become imaginary, indicating an instability.
2108.01351
Majid Modarres
N. Olanj and M. Modarres
A detailed study of charm content of a proton in the frameworks of the Kimber-Martin-Ryskin and Martin-Ryskin-Watt approaches
null
Nucl.Phys.A 998 (2020) 121735
10.1016/j.nuclphysa.2020.121735
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The charm structure function, ($F_2^{c\overline{c}}(x, Q^2)$), is calculated in the framework of the $k_t$-factorization formalism by using the unintegrated parton distribution functions (UPDF), which are generated through the Kimber et al. (KMR) and Martin et al. (MRW) procedures. The Martin group (MMHT2014) parton distribution functions (PDF) is used as the input PDF for the corresponding UPDF. The resulted $F_2^{c\overline{c}}(x, Q^2)$ is compared with the predicted data and the calculations given by the ZEUS and H1 collaborations, the parton pQCD theory, i.e. the general-mass variable-flavour-number scheme (GMVFNS), the LO collinear procedure and the saturation model introduced by Golec-Biernat and W\"usthoff (GBW), respectively. In general, it is shown that the calculated charm structure functions based on the stated above two UPDF schemes are consistent with the experimental data and other theoretical predictions. Also, a short discussion is presented regarding the KMR and MRW UPDF behaviors.
[ { "created": "Tue, 3 Aug 2021 08:12:28 GMT", "version": "v1" } ]
2021-08-04
[ [ "Olanj", "N.", "" ], [ "Modarres", "M.", "" ] ]
The charm structure function, ($F_2^{c\overline{c}}(x, Q^2)$), is calculated in the framework of the $k_t$-factorization formalism by using the unintegrated parton distribution functions (UPDF), which are generated through the Kimber et al. (KMR) and Martin et al. (MRW) procedures. The Martin group (MMHT2014) parton distribution functions (PDF) is used as the input PDF for the corresponding UPDF. The resulted $F_2^{c\overline{c}}(x, Q^2)$ is compared with the predicted data and the calculations given by the ZEUS and H1 collaborations, the parton pQCD theory, i.e. the general-mass variable-flavour-number scheme (GMVFNS), the LO collinear procedure and the saturation model introduced by Golec-Biernat and W\"usthoff (GBW), respectively. In general, it is shown that the calculated charm structure functions based on the stated above two UPDF schemes are consistent with the experimental data and other theoretical predictions. Also, a short discussion is presented regarding the KMR and MRW UPDF behaviors.
hep-ph/0507125
Vladimir Zhukovsky
D. Ebert (1), V.Ch. Zhukovsky (2), O.V. Tarasov (2) ((1) Institute of Physics, Humboldt-University, Berlin, Germany, (2) Physical Department, Moscow State University, Moscow, Russia)
Competition of Color Ferromagnetic and Superconductive States in a Quark-Gluon System
21 pages, 4 Postscript figures
Phys.Rev. D72 (2005) 096007
10.1103/PhysRevD.72.096007
null
hep-ph
null
The possibility of color ferromagnetism in an SU(2) gauge field model is investigated. The conditions allowing a stable color ferromagnetic state of the quark system in the chromomagnetic field occupying small domains are considered. A phase transition between this state and the color superconducting state is considered. The effect of finite temperature is analyzed.
[ { "created": "Mon, 11 Jul 2005 11:51:28 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ebert", "D.", "" ], [ "Zhukovsky", "V. Ch.", "" ], [ "Tarasov", "O. V.", "" ] ]
The possibility of color ferromagnetism in an SU(2) gauge field model is investigated. The conditions allowing a stable color ferromagnetic state of the quark system in the chromomagnetic field occupying small domains are considered. A phase transition between this state and the color superconducting state is considered. The effect of finite temperature is analyzed.
hep-ph/9905382
Cong-Feng Qiao
Cong-Feng Qiao, Han-Wen Huang and Kuang-Ta Chao
Large Possible retardation effects of quark confinement on the meson spectrum II
11 pages, RevTex, to appear in PRD
Phys.Rev. D60 (1999) 094004
10.1103/PhysRevD.60.094004
DESY 99-061 and PUTP-98-35
hep-ph
null
We present the results of a study of heavy-light-quark bound states in the context of the reduced Bethe-Salpeter equation with relativistic vector and scalar interactions. We find that satisfactory fits may also be obtained when the retarded effect of the quark-antiquark interaction is concerned.
[ { "created": "Tue, 18 May 1999 10:02:35 GMT", "version": "v1" } ]
2009-10-31
[ [ "Qiao", "Cong-Feng", "" ], [ "Huang", "Han-Wen", "" ], [ "Chao", "Kuang-Ta", "" ] ]
We present the results of a study of heavy-light-quark bound states in the context of the reduced Bethe-Salpeter equation with relativistic vector and scalar interactions. We find that satisfactory fits may also be obtained when the retarded effect of the quark-antiquark interaction is concerned.
hep-ph/0410125
Gursevil Turan
H. Acar and G. Turan
B-> X_d \ell^+\ell^- in a CP softly broken two Higgs doublet model
15 pages, 13 figures
Acta Phys.Polon. B35 (2004) 687-703
null
null
hep-ph
null
We study the differential branching ratio, forward-backward asymmetry, CP-violating asymmetry, CP-violating asymmetry in the forward-backward asymmetry and polarization asymmetries of the final lepton in the B-> X_d \ell^+\ell^- decays in the context of a CP softly broken two Higgs doublet model. We analyze the dependencies of these observables on the model parameters by paying a special attention to the effects of neutral Higgs boson (NHB) exchanges and possible CP violating effects. We find that NHB effects are quite significant for the \tau mode. The above-mentioned observables seems to be promising as a testing ground for new physics beyond the SM, especially for the existence of the CP-violating phase in the theory.
[ { "created": "Fri, 8 Oct 2004 06:51:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Acar", "H.", "" ], [ "Turan", "G.", "" ] ]
We study the differential branching ratio, forward-backward asymmetry, CP-violating asymmetry, CP-violating asymmetry in the forward-backward asymmetry and polarization asymmetries of the final lepton in the B-> X_d \ell^+\ell^- decays in the context of a CP softly broken two Higgs doublet model. We analyze the dependencies of these observables on the model parameters by paying a special attention to the effects of neutral Higgs boson (NHB) exchanges and possible CP violating effects. We find that NHB effects are quite significant for the \tau mode. The above-mentioned observables seems to be promising as a testing ground for new physics beyond the SM, especially for the existence of the CP-violating phase in the theory.
hep-ph/9408355
Joern Haeuser
J.M. Haeuser, W. Cassing, A. Peter and M.H. Thoma
Connected Green function approach to ground state symmetry breaking in $\Phi^4_{1+1}$-theory
25 Revtex pages, 5 figures available via fpt from the directory ugi-94-11 of ftp@theorie.physik.uni-giessen.de as one postscript file (there was a bug in our calculations, all numerical results and figures have changed significantly), ugi-94-11
Z.Phys. A353 (1996) 301-310
10.1007/BF01292336
null
hep-ph
null
Using the cluster expansions for n-point Green functions we derive a closed set of dynamical equations of motion for connected equal-time Green functions by neglecting all connected functions higher than $4^{th}$ order for the $\lambda \Phi^4$-theory in $1+1$ dimensions. We apply the equations to the investigation of spontaneous ground state symmetry breaking, i.e. to the evaluation of the effective potential at temperature $T=0$. Within our momentum space discretization we obtain a second order phase transition (in agreement with the Simon-Griffith theorem) and a critical coupling of $\lambda_{crit}/4m^2=2.446$ as compared to a first order phase transition and $\lambda_{crit}/4m^2=2.568$ from the Gaussian effective potential approach.
[ { "created": "Tue, 23 Aug 1994 12:23:13 GMT", "version": "v1" }, { "created": "Wed, 24 Aug 1994 16:54:22 GMT", "version": "v2" }, { "created": "Mon, 12 Sep 1994 13:22:58 GMT", "version": "v3" } ]
2009-10-28
[ [ "Haeuser", "J. M.", "" ], [ "Cassing", "W.", "" ], [ "Peter", "A.", "" ], [ "Thoma", "M. H.", "" ] ]
Using the cluster expansions for n-point Green functions we derive a closed set of dynamical equations of motion for connected equal-time Green functions by neglecting all connected functions higher than $4^{th}$ order for the $\lambda \Phi^4$-theory in $1+1$ dimensions. We apply the equations to the investigation of spontaneous ground state symmetry breaking, i.e. to the evaluation of the effective potential at temperature $T=0$. Within our momentum space discretization we obtain a second order phase transition (in agreement with the Simon-Griffith theorem) and a critical coupling of $\lambda_{crit}/4m^2=2.446$ as compared to a first order phase transition and $\lambda_{crit}/4m^2=2.568$ from the Gaussian effective potential approach.
hep-ph/9712312
Per Osland
P.N. Burrows (MIT) and P. Osland (Bergen and DESY)
Event Orientation in e+e- Annihilation
8 pages, LaTeX, 4 figures, uses epsf, to appear in the Proceedings of the XIIth International Workshop on High Energy Physics and Quantum Field Theory, 4-10 September 1997, Samara, Russia
null
null
DESY 97-244
hep-ph hep-ex
null
We review the orientation of e+e- \to q\bar q g events in terms of the polar and azimuthal angles of the event plane w.r.t. the electron beam direction. The asymmetry of the azimuthal-angle distribution is, like the left-right forward-backward polar-angle asymmetry, sensitive to parity-violating effects in three-jet events; these are presently being explored experimentally. We present these observables at O(\alpha_s) in perturbative QCD and discuss their dependence on longitudinal beam polarisation and c.m. energy. A moments analysis in terms of the orientation angles allows a more detailed test of QCD by isolating the independent helicity cross-sections.
[ { "created": "Tue, 9 Dec 1997 11:48:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Burrows", "P. N.", "", "MIT" ], [ "Osland", "P.", "", "Bergen and DESY" ] ]
We review the orientation of e+e- \to q\bar q g events in terms of the polar and azimuthal angles of the event plane w.r.t. the electron beam direction. The asymmetry of the azimuthal-angle distribution is, like the left-right forward-backward polar-angle asymmetry, sensitive to parity-violating effects in three-jet events; these are presently being explored experimentally. We present these observables at O(\alpha_s) in perturbative QCD and discuss their dependence on longitudinal beam polarisation and c.m. energy. A moments analysis in terms of the orientation angles allows a more detailed test of QCD by isolating the independent helicity cross-sections.
hep-ph/9909399
Ntu hexg
Xiao-Gang He and German Valencia
Comment on the Matrix Element of $O_{11}$
6 pages, Latex
Phys.Rev.D61:117501,2000
10.1103/PhysRevD.61.117501
ISU-HET-99-8
hep-ph
null
The gluon dipole operator, $O_{11}$, has received much attention recently because it can have a large coefficient in some SUSY extensions of the standard model. We find that the commonly used matrix element of $O_{11}$ of Bertolini, Eeg and Fabbrichesi is in rough (but accidental) numerical agreement with an estimate based on dimensional analysis.
[ { "created": "Thu, 16 Sep 1999 12:15:04 GMT", "version": "v1" } ]
2009-12-15
[ [ "He", "Xiao-Gang", "" ], [ "Valencia", "German", "" ] ]
The gluon dipole operator, $O_{11}$, has received much attention recently because it can have a large coefficient in some SUSY extensions of the standard model. We find that the commonly used matrix element of $O_{11}$ of Bertolini, Eeg and Fabbrichesi is in rough (but accidental) numerical agreement with an estimate based on dimensional analysis.
hep-ph/0701016
Ernest Ma
Ernest Ma (UC Riverside)
New Lepton Family Symmetry and Neutrino Tribimaximal Mixing
8 pages, no figure
Europhys.Lett.79:61001,2007
10.1209/0295-5075/79/61001
UCRHEP-T429 (Jan 07)
hep-ph
null
The newly proposed finite symmetry Sigma(81) is applied to the problem of neutrino tribimaximal mixing. The result is more satisfactory than those of previous models based on A_4 in that the use of auxiliary symmetries (or mechanisms) may be avoided. Deviations from the tribimaximal pattern are expected, but because of its basic structure, only tan^2 (theta_12) may differ significantly from 0.5 (say 0.45) with sin^2 (2 theta_23) remaining very close to one, and theta_13 very nearly zero.
[ { "created": "Tue, 2 Jan 2007 22:47:23 GMT", "version": "v1" }, { "created": "Tue, 31 Jul 2007 20:19:57 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
The newly proposed finite symmetry Sigma(81) is applied to the problem of neutrino tribimaximal mixing. The result is more satisfactory than those of previous models based on A_4 in that the use of auxiliary symmetries (or mechanisms) may be avoided. Deviations from the tribimaximal pattern are expected, but because of its basic structure, only tan^2 (theta_12) may differ significantly from 0.5 (say 0.45) with sin^2 (2 theta_23) remaining very close to one, and theta_13 very nearly zero.
2112.15570
Kun Wang
Kun Wang, Pengfu Tian, Jingya Zhu
Exploring Heavy Higgs Bosons at a 100 TeV Hadron Collider within the Semi-Constrained NMSSM
10 pages, 3 figures, 1 tables
Chin. Phys. C 48, no.9,093108 (2024)
10.1088/1674-1137/ad5663
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this study, we explore the detectability of heavy Higgs bosons in the $pp \to b\bar{b}H/A \to b\bar{b}t\bar{t}$ channel at a 100 TeV hadron collider within the semi-constrained Next-to-Minimal Supersymmetric Standard Model (NMSSM). We calculate their production cross sections and decay branching ratios, comparing these with simulation results from existing reference. We focus on the heavy, doublet-dominated CP-even Higgs $H$ and CP-odd Higgs $A$, with mass limits set below 10 TeV to ensure detectability. We find that at a collider with 3 ab$^{-1}$ of integrated luminosity, the potential for detecting heavy Higgs bosons varies significantly with their mass and $\tan\beta$. Heavy Higgs bosons below 2 TeV are within the testable range, while those heavier than 7 TeV fall below the exclusion and discovery thresholds, rendering them undetectable. For masses between 2 and 7 TeV, heavy Higgs bosons with $\tan\beta$ less than 20 can be detected, whereas those with $\tan\beta$ greater than 20 are beyond the current discovery or exclusion capabilities.
[ { "created": "Fri, 31 Dec 2021 17:51:12 GMT", "version": "v1" }, { "created": "Thu, 18 Apr 2024 15:05:25 GMT", "version": "v2" } ]
2024-07-26
[ [ "Wang", "Kun", "" ], [ "Tian", "Pengfu", "" ], [ "Zhu", "Jingya", "" ] ]
In this study, we explore the detectability of heavy Higgs bosons in the $pp \to b\bar{b}H/A \to b\bar{b}t\bar{t}$ channel at a 100 TeV hadron collider within the semi-constrained Next-to-Minimal Supersymmetric Standard Model (NMSSM). We calculate their production cross sections and decay branching ratios, comparing these with simulation results from existing reference. We focus on the heavy, doublet-dominated CP-even Higgs $H$ and CP-odd Higgs $A$, with mass limits set below 10 TeV to ensure detectability. We find that at a collider with 3 ab$^{-1}$ of integrated luminosity, the potential for detecting heavy Higgs bosons varies significantly with their mass and $\tan\beta$. Heavy Higgs bosons below 2 TeV are within the testable range, while those heavier than 7 TeV fall below the exclusion and discovery thresholds, rendering them undetectable. For masses between 2 and 7 TeV, heavy Higgs bosons with $\tan\beta$ less than 20 can be detected, whereas those with $\tan\beta$ greater than 20 are beyond the current discovery or exclusion capabilities.
hep-ph/0308010
Ingo Schienbein
I. Schienbein and J.-Y. Yu
Pion absorption and rescattering in the ANP model revisited
8 pp. To appear in the proceedings of 2nd International Workshop on Neutrino - Nucleus Interactions in the Few GeV Region (NUINT 02), Irvine, California, 12-15 Dec 2002
null
null
null
hep-ph
null
Single pion leptoproduction in the region of the (3,3) resonance is currently of high interest for at least two reasons: (i) These reactions constitute an important part of the total cross section in low energy reactions and are utilized to detect neutrino oscillations in current and future long baseline experiments. (ii) Intranuclear rescattering of the pions in heavy nuclei results in interesting and sizable modifications of the free nucleon cross sections which are testable in electroproduction experiments. In this article we give a basic introduction to the pion multiple scattering model of Adler, Nussinov, and Paschos (ANP) with special emphasis on pion absorption. We also estimate the probability of multiple scattering.
[ { "created": "Fri, 1 Aug 2003 11:19:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Schienbein", "I.", "" ], [ "Yu", "J. -Y.", "" ] ]
Single pion leptoproduction in the region of the (3,3) resonance is currently of high interest for at least two reasons: (i) These reactions constitute an important part of the total cross section in low energy reactions and are utilized to detect neutrino oscillations in current and future long baseline experiments. (ii) Intranuclear rescattering of the pions in heavy nuclei results in interesting and sizable modifications of the free nucleon cross sections which are testable in electroproduction experiments. In this article we give a basic introduction to the pion multiple scattering model of Adler, Nussinov, and Paschos (ANP) with special emphasis on pion absorption. We also estimate the probability of multiple scattering.
2012.08506
Javier Fuentes-Mart\'in
Javier Fuentes-Martin, Matthias K\"onig, Julie Pag\`es, Anders Eller Thomsen, Felix Wilsch
SuperTracer: A Calculator of Functional Supertraces for One-Loop EFT Matching
38 pages, 1 figure. The code and example notebooks are publicly available at https://gitlab.com/supertracer/supertracer
JHEP 04 (2021) 281
10.1007/JHEP04(2021)281
MITP-20-076, TUM-HEP-1302/20, ZU-TH-54/20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present SuperTracer, a Mathematica package aimed at facilitating the functional matching procedure for generic UV models. This package automates the most tedious parts of one-loop functional matching computations. Namely, the determination and evaluation of all relevant supertraces, including loop integration and Dirac algebra manipulations. The current version of SuperTracer also contains a limited set of output simplifications. However, a further reduction of the output to a minimal basis using Fierz identities, integration by parts, simplification of Dirac structures, and/or light field redefinitions might still be necessary. The code and example notebooks are publicly available at https://gitlab.com/supertracer/supertracer.
[ { "created": "Tue, 15 Dec 2020 18:56:28 GMT", "version": "v1" }, { "created": "Sun, 1 Aug 2021 21:28:52 GMT", "version": "v2" } ]
2021-08-03
[ [ "Fuentes-Martin", "Javier", "" ], [ "König", "Matthias", "" ], [ "Pagès", "Julie", "" ], [ "Thomsen", "Anders Eller", "" ], [ "Wilsch", "Felix", "" ] ]
We present SuperTracer, a Mathematica package aimed at facilitating the functional matching procedure for generic UV models. This package automates the most tedious parts of one-loop functional matching computations. Namely, the determination and evaluation of all relevant supertraces, including loop integration and Dirac algebra manipulations. The current version of SuperTracer also contains a limited set of output simplifications. However, a further reduction of the output to a minimal basis using Fierz identities, integration by parts, simplification of Dirac structures, and/or light field redefinitions might still be necessary. The code and example notebooks are publicly available at https://gitlab.com/supertracer/supertracer.
1512.08563
Li-Sheng Geng
Li-Sheng Geng and Eulogio Oset
Novel nonperturbative approach for radiative $\bar{B}^0(\bar{B}^0_s)\rightarrow J/\psi \gamma$ decays
More justifications for the decay mechanism. Results remain the same. To appear in Physical Review D
Phys. Rev. D 94, 014018 (2016)
10.1103/PhysRevD.94.014018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Radiative $\bar{B}^0(\bar{B}^0_s)\rightarrow J/\psi \gamma$ decays provide an interesting case to test our understanding of (non)perturbative QCD and eventually to probe physics beyond the standard model. Recently, the LHCb Collaboration has reported an upper bound, updating the results of the BABAR Collaboration. Previous theoretical predictions based on QCD factorization or perturbative QCD have shown large variations due to different treatment of nonfactorizable contributions and meson-photon transitions. In this paper, we report on a novel approach to estimate the decay rates, which is based on a recently proposed model for $B$ decays and the vector meson dominance hypothesis, widely tested in the relevant energy regions. The predicted branching ratios are $\mathrm{Br}[\bar{B}^0\rightarrow J/\psi\gamma]=\left(3.50\pm0.34^{+1.12}_{-0.63}\right)\times10^{-8}$ and $\mathrm{Br}[\bar{B}^0_s\rightarrow J/\psi\gamma]=\left(7.20\pm0.68^{+2.31}_{-1.30}\right)\times10^{-7}$. The first uncertainty is systematic and the second is statistical, originating from the experimental $\bar{B}^0_s\rightarrow J/\psi \phi$ branching ratio.
[ { "created": "Tue, 29 Dec 2015 00:05:07 GMT", "version": "v1" }, { "created": "Sun, 17 Jul 2016 08:51:15 GMT", "version": "v2" } ]
2016-07-27
[ [ "Geng", "Li-Sheng", "" ], [ "Oset", "Eulogio", "" ] ]
Radiative $\bar{B}^0(\bar{B}^0_s)\rightarrow J/\psi \gamma$ decays provide an interesting case to test our understanding of (non)perturbative QCD and eventually to probe physics beyond the standard model. Recently, the LHCb Collaboration has reported an upper bound, updating the results of the BABAR Collaboration. Previous theoretical predictions based on QCD factorization or perturbative QCD have shown large variations due to different treatment of nonfactorizable contributions and meson-photon transitions. In this paper, we report on a novel approach to estimate the decay rates, which is based on a recently proposed model for $B$ decays and the vector meson dominance hypothesis, widely tested in the relevant energy regions. The predicted branching ratios are $\mathrm{Br}[\bar{B}^0\rightarrow J/\psi\gamma]=\left(3.50\pm0.34^{+1.12}_{-0.63}\right)\times10^{-8}$ and $\mathrm{Br}[\bar{B}^0_s\rightarrow J/\psi\gamma]=\left(7.20\pm0.68^{+2.31}_{-1.30}\right)\times10^{-7}$. The first uncertainty is systematic and the second is statistical, originating from the experimental $\bar{B}^0_s\rightarrow J/\psi \phi$ branching ratio.
hep-ph/9710510
Robert Kaminski
Chueng-Ryong Ji, Robert Kaminski, Leonard Lesniak, Adam Szczepaniak, Robert Williams
Coupled Channel Analysis of S-Wave Pion-Pion and Kaon-Kaon Photoproduction
40 pages including 18 figures, minor modifications
Phys.Rev.C58:1205-1217,1998
10.1103/PhysRevC.58.1205
INP-1769/PH, Cracow, Poland
hep-ph
null
We present a coupled channel partial wave analysis of nondiffractive S-wave pi+ pi- and K+ K- photoproduction focusing on the KK threshold. Final state interactions are included. We calculate total cross sections, angular and effective mass distributions in both pion-pion and kaon-antikaon channels. Our results indicate that these processes are experimentally measurable and valuable information on the f0(980) resonance structure can be obtained.
[ { "created": "Tue, 28 Oct 1997 16:12:37 GMT", "version": "v1" }, { "created": "Wed, 29 Oct 1997 11:00:25 GMT", "version": "v2" }, { "created": "Wed, 3 Feb 1999 11:00:24 GMT", "version": "v3" } ]
2008-11-26
[ [ "Ji", "Chueng-Ryong", "" ], [ "Kaminski", "Robert", "" ], [ "Lesniak", "Leonard", "" ], [ "Szczepaniak", "Adam", "" ], [ "Williams", "Robert", "" ] ]
We present a coupled channel partial wave analysis of nondiffractive S-wave pi+ pi- and K+ K- photoproduction focusing on the KK threshold. Final state interactions are included. We calculate total cross sections, angular and effective mass distributions in both pion-pion and kaon-antikaon channels. Our results indicate that these processes are experimentally measurable and valuable information on the f0(980) resonance structure can be obtained.
hep-ph/9609455
Kingman Cheung
Kingman Cheung and Dennis Silverman
Limits on Anomalous Couplings of Quarks From Prompt Photon Data
LaTeX2e, using the package-graphicx, 3 figures. It will appear in the Proceedings of the 1996 DPF/DPB Summer Study on New Direction for High Energy Physics, Snowmass, CO
null
null
UTEXAS-HEP-96-14, UCI-TR-96-33
hep-ph
null
Prompt photon production has been known to be a sensitive probe to the gluon luminosity inside a hadron because it is mainly produced by quark-gluon scattering. For the same reason prompt photon production should also be sensitive to the anomalous couplings of gluons to quarks. We will examine the effects of two specific anomalous couplings -- chromoelectric and chromomagnetic dipole moments of quarks -- on the prompt photon production. Using the data collected by CDF and D0 at the Tevatron we put a bound on the these anomalous couplings.
[ { "created": "Tue, 24 Sep 1996 19:54:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cheung", "Kingman", "" ], [ "Silverman", "Dennis", "" ] ]
Prompt photon production has been known to be a sensitive probe to the gluon luminosity inside a hadron because it is mainly produced by quark-gluon scattering. For the same reason prompt photon production should also be sensitive to the anomalous couplings of gluons to quarks. We will examine the effects of two specific anomalous couplings -- chromoelectric and chromomagnetic dipole moments of quarks -- on the prompt photon production. Using the data collected by CDF and D0 at the Tevatron we put a bound on the these anomalous couplings.
0708.3526
Hyun-Chul Kim
Klaus Goeke, Hyun-Chul Kim, M.M. Musakhanov, Marat Siddikov
1/N_c corrections to the magnetic susceptibility of the QCD vacuum
18 pages, 5 figures. Final version to appear in Phys. Rev. D
Phys.Rev.D76:116007,2007
10.1103/PhysRevD.76.116007
PNU-NTG-09/2007
hep-ph
null
We investigate the magnetic susceptibility of the QCD vacuum with the $1/N_c$ corrections taken into account, based on the instanton vacuum. Starting from the instanton liquid model we derive the gauged light-quark partition function in the presence of the current quark mass as well as of external Abelian vector and tensor fields. We consider the $1/N_c$ meson-loop corrections which are shown to contribute to the magnetic susceptibility by around 15% for the up (and down) quarks. We also take into account the tensor terms of the quark-quark interaction from the instanton vacuum as well as the finite-width effects, both of which are of order $\mathcal{O}(1/N_c)$. The effects of the tensor terms and finite width turn out to be negligibly small. The final results for the up-quarks are given as: $\chi< i\psi^\dagger \psi>_0 \simeq 35-40 \mathrm{MeV}$ with the quark condensate $<i\psi^\dagger \psi>_0$. We also discuss the pion mass dependence of the magnetic susceptibility in order to give a qualitative guideline for the chiral extrapolation of lattice data.
[ { "created": "Mon, 27 Aug 2007 02:20:50 GMT", "version": "v1" }, { "created": "Wed, 12 Sep 2007 01:39:04 GMT", "version": "v2" }, { "created": "Sat, 17 Nov 2007 06:34:04 GMT", "version": "v3" } ]
2008-11-26
[ [ "Goeke", "Klaus", "" ], [ "Kim", "Hyun-Chul", "" ], [ "Musakhanov", "M. M.", "" ], [ "Siddikov", "Marat", "" ] ]
We investigate the magnetic susceptibility of the QCD vacuum with the $1/N_c$ corrections taken into account, based on the instanton vacuum. Starting from the instanton liquid model we derive the gauged light-quark partition function in the presence of the current quark mass as well as of external Abelian vector and tensor fields. We consider the $1/N_c$ meson-loop corrections which are shown to contribute to the magnetic susceptibility by around 15% for the up (and down) quarks. We also take into account the tensor terms of the quark-quark interaction from the instanton vacuum as well as the finite-width effects, both of which are of order $\mathcal{O}(1/N_c)$. The effects of the tensor terms and finite width turn out to be negligibly small. The final results for the up-quarks are given as: $\chi< i\psi^\dagger \psi>_0 \simeq 35-40 \mathrm{MeV}$ with the quark condensate $<i\psi^\dagger \psi>_0$. We also discuss the pion mass dependence of the magnetic susceptibility in order to give a qualitative guideline for the chiral extrapolation of lattice data.
1801.06458
Paolo Torrielli
Lorenzo Magnea, Ezio Maina, Paolo Torrielli, Sandro Uccirati
Towards analytic local sector subtraction at NNLO
10 pages, contribution to the proceedings of `RADCOR 2017', St. Gilgen (Austria), September 2017
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new method for local subtraction at next-to-next-to-leading order in QCD is sketched, attempting to conjugate the minimal counterterm structure arising from a sector partition of the radiation phase space with the simplifications following from analytic integration of the counterterms.
[ { "created": "Fri, 19 Jan 2018 15:24:56 GMT", "version": "v1" }, { "created": "Tue, 24 Jul 2018 14:24:50 GMT", "version": "v2" } ]
2018-07-25
[ [ "Magnea", "Lorenzo", "" ], [ "Maina", "Ezio", "" ], [ "Torrielli", "Paolo", "" ], [ "Uccirati", "Sandro", "" ] ]
A new method for local subtraction at next-to-next-to-leading order in QCD is sketched, attempting to conjugate the minimal counterterm structure arising from a sector partition of the radiation phase space with the simplifications following from analytic integration of the counterterms.
hep-ph/0404020
Toshifumi Yamashita
Nobuhiro Maekawa and Toshifumi Yamashita
Horizontal symmetry in Higgs sector of GUT with U(1)_A symmetry
35 pages
JHEP 0407 (2004) 009
10.1088/1126-6708/2004/07/009
KUNS-1906
hep-ph
null
In a series of papers, we pointed out that an anomalous $U(1)_A$ gauge symmetry naturally solves various problems in grand unified theories (GUTs) and that a horizontal gauge symmetry, $SU(2)_H$ or $SU(3)_H$, not only realizes the unification of three generation quarks and leptons in fewer multiplets but also solves the supersymmetric flavor problem. In this paper, we examine the possibility that the Higgs sectors of the GUT symmetry and of the horizontal symmetry are unified, that is, there are some Higgs fields whose vacuum expectation values (VEVs) break both the GUT gauge symmetry and the horizontal symmetry at the same time. Although the scale of the VEVs become too large to suppress the flavor changing neutral current processes sufficiently, the unification is possible. In addition, for the $SU(3)_H$ models, the $SU(3)_H$ gauge anomaly is cancelled in the unified models without introducing additional fields in contrast with the previous models in which the Higgs sectors are not unified.
[ { "created": "Fri, 2 Apr 2004 12:09:21 GMT", "version": "v1" } ]
2009-11-10
[ [ "Maekawa", "Nobuhiro", "" ], [ "Yamashita", "Toshifumi", "" ] ]
In a series of papers, we pointed out that an anomalous $U(1)_A$ gauge symmetry naturally solves various problems in grand unified theories (GUTs) and that a horizontal gauge symmetry, $SU(2)_H$ or $SU(3)_H$, not only realizes the unification of three generation quarks and leptons in fewer multiplets but also solves the supersymmetric flavor problem. In this paper, we examine the possibility that the Higgs sectors of the GUT symmetry and of the horizontal symmetry are unified, that is, there are some Higgs fields whose vacuum expectation values (VEVs) break both the GUT gauge symmetry and the horizontal symmetry at the same time. Although the scale of the VEVs become too large to suppress the flavor changing neutral current processes sufficiently, the unification is possible. In addition, for the $SU(3)_H$ models, the $SU(3)_H$ gauge anomaly is cancelled in the unified models without introducing additional fields in contrast with the previous models in which the Higgs sectors are not unified.
2406.07321
Chris White
Chris D. White and Martin J. White
The magic of entangled top quarks
22 pages, 6 figures
null
null
ADP-24-10/T1249
hep-ph hep-ex hep-th quant-ph
http://creativecommons.org/licenses/by/4.0/
Recent years have seen an increasing body of work examining how quantum entanglement can be measured at high energy particle physics experiments, thereby complementing traditional table-top experiments. This raises the question of whether more concepts from quantum computation can be examined at colliders, and we here consider the property of magic, which distinguishes those quantum states which have a genuine computational advantage over classical states. We examine top anti-top pair production at the LHC, showing that nature chooses to produce magic tops, where the amount of magic varies with the kinematics of the final state. We compare results for individual partonic channels and at proton-level, showing that averaging over final states typically increases magic. This is in contrast to entanglement measures, such as the concurrence, which typically decrease. Our results create new links between the quantum information and particle physics literatures, providing practical insights for further study.
[ { "created": "Tue, 11 Jun 2024 14:50:56 GMT", "version": "v1" }, { "created": "Wed, 12 Jun 2024 10:26:04 GMT", "version": "v2" } ]
2024-06-13
[ [ "White", "Chris D.", "" ], [ "White", "Martin J.", "" ] ]
Recent years have seen an increasing body of work examining how quantum entanglement can be measured at high energy particle physics experiments, thereby complementing traditional table-top experiments. This raises the question of whether more concepts from quantum computation can be examined at colliders, and we here consider the property of magic, which distinguishes those quantum states which have a genuine computational advantage over classical states. We examine top anti-top pair production at the LHC, showing that nature chooses to produce magic tops, where the amount of magic varies with the kinematics of the final state. We compare results for individual partonic channels and at proton-level, showing that averaging over final states typically increases magic. This is in contrast to entanglement measures, such as the concurrence, which typically decrease. Our results create new links between the quantum information and particle physics literatures, providing practical insights for further study.
2202.08858
M.C. David Marsh
Ricardo Z. Ferreira, M.C. David Marsh and Eike M\"uller
Do direct detection experiments constrain axionlike particles coupled to electrons?
4 pages, 2 figures. v2: references added, typos corrected (results unchanged)
null
10.1103/PhysRevLett.128.221302
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Several laboratory experiments have published limits on axionlike particles (ALPs) with feeble couplings to electrons and masses in the keV-MeV range, under the assumption that such ALPs comprise the dark matter. We note that ALPs decay radiatively into photons, and show that for a large subset of the parameter space ostensibly probed by these experiments, the lifetime of the ALPs is shorter than the age of the universe. Such ALPs cannot consistently make up the dark matter, which significantly affects the interpretation of published limits from GERDA, Edelweiss-III, SuperCDMS and Majorana. Moreover, constraints from gamma-ray and X-ray astronomy exclude an even wider range of the ALP-electron coupling, and supersede all current experimental limits on dark matter ALPs in the 6 keV to 1 MeV mass range. These conclusions are rather model-independent, and can only be avoided at the expense of significant fine-tuning in theories where the ALP has additional couplings to other particles.
[ { "created": "Thu, 17 Feb 2022 19:01:41 GMT", "version": "v1" }, { "created": "Tue, 22 Feb 2022 17:12:47 GMT", "version": "v2" } ]
2022-06-15
[ [ "Ferreira", "Ricardo Z.", "" ], [ "Marsh", "M. C. David", "" ], [ "Müller", "Eike", "" ] ]
Several laboratory experiments have published limits on axionlike particles (ALPs) with feeble couplings to electrons and masses in the keV-MeV range, under the assumption that such ALPs comprise the dark matter. We note that ALPs decay radiatively into photons, and show that for a large subset of the parameter space ostensibly probed by these experiments, the lifetime of the ALPs is shorter than the age of the universe. Such ALPs cannot consistently make up the dark matter, which significantly affects the interpretation of published limits from GERDA, Edelweiss-III, SuperCDMS and Majorana. Moreover, constraints from gamma-ray and X-ray astronomy exclude an even wider range of the ALP-electron coupling, and supersede all current experimental limits on dark matter ALPs in the 6 keV to 1 MeV mass range. These conclusions are rather model-independent, and can only be avoided at the expense of significant fine-tuning in theories where the ALP has additional couplings to other particles.
1305.6457
Marek Karliner
Yitzhak Frishman and Marek Karliner
Tetraquarks, their Masses and Decays in QED_2
LaTeX, 9 pages, 2 figures; notation clarified, some minor corrections
null
10.1007/JHEP08(2013)096
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent observations by Belle and BESIII of charged quarkonium-like resonances give new stimulus for theoretical investigation of exotic hadrons in general and heavy tetraquarks in particular. We use QED_2, a confining theory, as a model for the masses and decays of tetraquarks. Here we discuss the states (Q Qbar q qbar) and (Q Q qbar qbar) (and its anti-particle), where Q and q are two fermion flavors with masses M and m, so that M > m. We then discuss decay modes of these states into (Q Qqbar), (q qbar), (Q qbar), (Qbar q). It turns out that (Q Qbar q qbar) is stable, while (Q Q qbar qbar) is not.
[ { "created": "Tue, 28 May 2013 11:43:53 GMT", "version": "v1" }, { "created": "Tue, 11 Jun 2013 13:14:30 GMT", "version": "v2" }, { "created": "Wed, 12 Jun 2013 08:57:19 GMT", "version": "v3" } ]
2015-06-16
[ [ "Frishman", "Yitzhak", "" ], [ "Karliner", "Marek", "" ] ]
Recent observations by Belle and BESIII of charged quarkonium-like resonances give new stimulus for theoretical investigation of exotic hadrons in general and heavy tetraquarks in particular. We use QED_2, a confining theory, as a model for the masses and decays of tetraquarks. Here we discuss the states (Q Qbar q qbar) and (Q Q qbar qbar) (and its anti-particle), where Q and q are two fermion flavors with masses M and m, so that M > m. We then discuss decay modes of these states into (Q Qqbar), (q qbar), (Q qbar), (Qbar q). It turns out that (Q Qbar q qbar) is stable, while (Q Q qbar qbar) is not.
hep-ph/9806211
null
Hsiang-nan Li
Small-x evolution with Q dependence and unitarity
12 pages in Latex
null
null
NCKU-HEP-98-06
hep-ph
null
We propose a modified Balitsky-Fadin-Kuraev-Lipatov equation from the viewpoint of the resummation technique, which contains an intrinsic dependence on momentum transfer Q, and satisfies the unitarity bound. The idea is to relax the strong rapidity ordering and to restrict phase space for real gluon emissions in the evaluation of the BFKL kernel. It is shown that the power-law rise of the gluon distribution function with the small Bjorken variable x turns into a logarithmic rise, and that the predictions for the proton structure function $F_2(x,Q^2)$ are consistent with the HERA data.
[ { "created": "Mon, 1 Jun 1998 07:41:33 GMT", "version": "v1" } ]
2016-09-06
[ [ "Li", "Hsiang-nan", "" ] ]
We propose a modified Balitsky-Fadin-Kuraev-Lipatov equation from the viewpoint of the resummation technique, which contains an intrinsic dependence on momentum transfer Q, and satisfies the unitarity bound. The idea is to relax the strong rapidity ordering and to restrict phase space for real gluon emissions in the evaluation of the BFKL kernel. It is shown that the power-law rise of the gluon distribution function with the small Bjorken variable x turns into a logarithmic rise, and that the predictions for the proton structure function $F_2(x,Q^2)$ are consistent with the HERA data.
1207.6233
Norma Susana Mankoc Borstnik
Norma Susana Mankoc Borstnik
How many scalar fields there are and how are they related to fermions and weak bosons in the spin-charge-family theory?
16 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spin-charge-family theory offers a possible explanation for the assumptions of the standard model, interpreting the standard model as its low energy effective manifestation. The standard model Higgs and Yukawa couplings are explained as an effective replacement for several scalar fields, all of bosonic (adjoint) representations with respect to all the charge groups, with the family groups included. Assuming the Lagrange function for all scalar fields to be of the renormalizable kind, properties of the scalar fields on the tree level are discussed. Free scalar fields (mass eigenstates) differ from either those, which couple to $Z_m$, or to $W^{\pm}_{m}$ or to each family member of each of the four families, which further differ among themselves. Consequently the spin-charge-family theory predictions differ from those of the standard model.
[ { "created": "Thu, 26 Jul 2012 10:36:26 GMT", "version": "v1" } ]
2012-07-27
[ [ "Borstnik", "Norma Susana Mankoc", "" ] ]
The spin-charge-family theory offers a possible explanation for the assumptions of the standard model, interpreting the standard model as its low energy effective manifestation. The standard model Higgs and Yukawa couplings are explained as an effective replacement for several scalar fields, all of bosonic (adjoint) representations with respect to all the charge groups, with the family groups included. Assuming the Lagrange function for all scalar fields to be of the renormalizable kind, properties of the scalar fields on the tree level are discussed. Free scalar fields (mass eigenstates) differ from either those, which couple to $Z_m$, or to $W^{\pm}_{m}$ or to each family member of each of the four families, which further differ among themselves. Consequently the spin-charge-family theory predictions differ from those of the standard model.
2312.14868
Maksym Ovchynnikov
Martina Ferrillo, Maksym Ovchynnikov, Filippo Resnati, Albert De Roeck
Improving the potential of BDF@SPS to search for new physics with liquid argon time projection chambers
journal version
JHEP 02 (2024) 196
10.1007/JHEP02(2024)196
null
hep-ph physics.ins-det
http://creativecommons.org/licenses/by/4.0/
Beam dump experiments proposed at the SPS are perfectly suited to explore the parameter space of models with long-lived particles, thanks to the combination of a large intensity with a high proton beam energy. In this paper, we study how the exploration power may be augmented further by installing a detector based on liquid argon time projection chamber technology. In particular, we consider several signatures of new physics particles that may be uniquely searched for with such a detector, including double bang events with heavy neutral leptons, inelastic light dark matter, and millicharged particles.
[ { "created": "Fri, 22 Dec 2023 17:45:56 GMT", "version": "v1" }, { "created": "Thu, 7 Mar 2024 08:56:03 GMT", "version": "v2" } ]
2024-03-08
[ [ "Ferrillo", "Martina", "" ], [ "Ovchynnikov", "Maksym", "" ], [ "Resnati", "Filippo", "" ], [ "De Roeck", "Albert", "" ] ]
Beam dump experiments proposed at the SPS are perfectly suited to explore the parameter space of models with long-lived particles, thanks to the combination of a large intensity with a high proton beam energy. In this paper, we study how the exploration power may be augmented further by installing a detector based on liquid argon time projection chamber technology. In particular, we consider several signatures of new physics particles that may be uniquely searched for with such a detector, including double bang events with heavy neutral leptons, inelastic light dark matter, and millicharged particles.
0709.2235
Masakiyo Kitazawa
Masakiyo Kitazawa, Dirk H. Rischke and Igor A. Shovkovy
Bound diquarks and their Bose-Einstein condensation in strongly coupled quark matter
7 pages, 6 figures
Phys.Lett.B663:228-233,2008
10.1016/j.physletb.2008.03.067
null
hep-ph
null
We explore the formation of diquark molecules and their Bose-Einstein condensation (BEC) in the phase diagram of three-flavor quark matter at nonzero temperature, T, and quark chemical potential, mu. Using a quark model with a four-fermion interaction, we identify possible diquark excitations as poles of the microscopically computed diquark propagator. The quark masses are obtained by solving a dynamical equation for the chiral condensate and are found to determine the stability of the diquark excitations. The stability of diquark excitations is investigated in the T-mu plane for different values of the diquark coupling strength. We find that bound diquark molecules appear at small quark chemical potentials at intermediate coupling and that BEC of non-strange diquark molecules occurs if the attractive interaction between quarks is sufficiently strong.
[ { "created": "Fri, 14 Sep 2007 09:09:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kitazawa", "Masakiyo", "" ], [ "Rischke", "Dirk H.", "" ], [ "Shovkovy", "Igor A.", "" ] ]
We explore the formation of diquark molecules and their Bose-Einstein condensation (BEC) in the phase diagram of three-flavor quark matter at nonzero temperature, T, and quark chemical potential, mu. Using a quark model with a four-fermion interaction, we identify possible diquark excitations as poles of the microscopically computed diquark propagator. The quark masses are obtained by solving a dynamical equation for the chiral condensate and are found to determine the stability of the diquark excitations. The stability of diquark excitations is investigated in the T-mu plane for different values of the diquark coupling strength. We find that bound diquark molecules appear at small quark chemical potentials at intermediate coupling and that BEC of non-strange diquark molecules occurs if the attractive interaction between quarks is sufficiently strong.
1702.00134
Aiichi Iwazaki
Aiichi Iwazaki
Chiral Symmetry Breaking by Monopole Condensation
7 pages, sectioning the manuscript
null
10.1142/S0217751X17501391
Nisho-2-2017
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Under the assumption of Abelian dominance in QCD, we have shown that chiral condensate is locally present around each QCD monopole. The essence is that either of charge or chirality of a quark is not conserved, when the low energy massless quark collides with QCD monopole. In reality, the charge is conserved so that the chirality is not conserved. Reviewing the presence of the local chiral condensate, we show by using chiral anomaly that chiral non symmetric quark pair production takes place when a quark is putted in a vacuum with monopole condensation, while chiral symmetric pair production takes place in a vacuum with no monopole condensation. Our results strongly indicate that the chiral symmetry is broken by the monopole condensation.
[ { "created": "Wed, 1 Feb 2017 05:10:06 GMT", "version": "v1" }, { "created": "Tue, 6 Jun 2017 01:12:23 GMT", "version": "v2" }, { "created": "Mon, 12 Jun 2017 02:48:12 GMT", "version": "v3" }, { "created": "Tue, 1 Aug 2017 05:55:43 GMT", "version": "v4" } ]
2017-09-13
[ [ "Iwazaki", "Aiichi", "" ] ]
Under the assumption of Abelian dominance in QCD, we have shown that chiral condensate is locally present around each QCD monopole. The essence is that either of charge or chirality of a quark is not conserved, when the low energy massless quark collides with QCD monopole. In reality, the charge is conserved so that the chirality is not conserved. Reviewing the presence of the local chiral condensate, we show by using chiral anomaly that chiral non symmetric quark pair production takes place when a quark is putted in a vacuum with monopole condensation, while chiral symmetric pair production takes place in a vacuum with no monopole condensation. Our results strongly indicate that the chiral symmetry is broken by the monopole condensation.
hep-ph/9501342
Volker Keiner
V. Keiner
A Spectator-Quark-Model for the Photoproduction of Kaons
16 pages, LaTex, 10 figures included; packed with 'uufiles' utility
Z.Phys.A352:215,1995
10.1007/BF01298911
Bonn TK-95-3
hep-ph
null
A simple model for the photoproduction of kaons off protons with a lambda hyperon in the final state is presented. In a quark model, the interaction is modelled by the pair-creation of the (anti-) strange quarks in the final state which recombine with the three quarks of the proton to form the lambda and kaon. The calculated scattering cross sections for photon energies up to $E_\gamma = 1.9 \; \mbox{GeV}$ are compared to experiment. The pair-creation process is found to have a significant contribution to the total cross section.
[ { "created": "Thu, 19 Jan 1995 16:28:50 GMT", "version": "v1" }, { "created": "Fri, 20 Jan 1995 09:42:48 GMT", "version": "v2" } ]
2011-07-19
[ [ "Keiner", "V.", "" ] ]
A simple model for the photoproduction of kaons off protons with a lambda hyperon in the final state is presented. In a quark model, the interaction is modelled by the pair-creation of the (anti-) strange quarks in the final state which recombine with the three quarks of the proton to form the lambda and kaon. The calculated scattering cross sections for photon energies up to $E_\gamma = 1.9 \; \mbox{GeV}$ are compared to experiment. The pair-creation process is found to have a significant contribution to the total cross section.