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1703.08402
Yan-Qing Ma
Yan-Qing Ma and Kuang-Ta Chao
New factorization theory for heavy quarkonium production and decay
12 pages, 3 figures, version published in PRD
Phys. Rev. D 100, 094007 (2019)
10.1103/PhysRevD.100.094007
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The widely used nonrelativistic QCD (NRQCD) factorization theory now encounters some notable difficulties in describing quarkonium production. This may be due to the inadequate treatment of soft hadrons emitted in the hadronization process, which causes bad convergence of velocity expansion in NRQCD. In this paper, starting from QCD we propose a rigorously defined factorization approach, soft gluon factorization (SGF), to better deal with the effects of soft hadrons. After a careful velocity expansion, the SGF can be as simple as the NRQCD factorization in phenomenological studies, but has a much better convergence. The SGF may provide a new insight to understand the mechanisms of quarkonium production and decay.
[ { "created": "Fri, 24 Mar 2017 13:26:47 GMT", "version": "v1" }, { "created": "Mon, 11 Nov 2019 22:39:46 GMT", "version": "v2" } ]
2019-11-13
[ [ "Ma", "Yan-Qing", "" ], [ "Chao", "Kuang-Ta", "" ] ]
The widely used nonrelativistic QCD (NRQCD) factorization theory now encounters some notable difficulties in describing quarkonium production. This may be due to the inadequate treatment of soft hadrons emitted in the hadronization process, which causes bad convergence of velocity expansion in NRQCD. In this paper, starting from QCD we propose a rigorously defined factorization approach, soft gluon factorization (SGF), to better deal with the effects of soft hadrons. After a careful velocity expansion, the SGF can be as simple as the NRQCD factorization in phenomenological studies, but has a much better convergence. The SGF may provide a new insight to understand the mechanisms of quarkonium production and decay.
hep-ph/0102091
D. P. Roy
D. P. Roy
Looking for the Charged Higgs Boson at LHC
Latex, 8 pages, 4 figures
null
null
TIFR/TH/01-04
hep-ph
null
I discuss LHC signatures of the charged Higgs boson of the MSSM, focussing mainly on the case of the charged Higgs boson being heavier than top quark.
[ { "created": "Thu, 8 Feb 2001 09:48:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Roy", "D. P.", "" ] ]
I discuss LHC signatures of the charged Higgs boson of the MSSM, focussing mainly on the case of the charged Higgs boson being heavier than top quark.
hep-ph/9910360
Carli
T. Carli
Determination of the Strong Coupling Constant in Jet Production at HERA
Talk presented at the EPS conference 1999, Tampere, Finnland
null
null
MPI-99-14
hep-ph
null
Recent \alphas determinations from jet production at HERA are presented. Three different observables lead to consistent alpha values. The result is consistent with the world average and has an error of about 0.006. This is quite a remarkable result, since it is only slightly less precise than the world average.
[ { "created": "Fri, 15 Oct 1999 13:33:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Carli", "T.", "" ] ]
Recent \alphas determinations from jet production at HERA are presented. Three different observables lead to consistent alpha values. The result is consistent with the world average and has an error of about 0.006. This is quite a remarkable result, since it is only slightly less precise than the world average.
2209.00666
Gauthier Durieux
Gauthier Durieux, Matthew McCullough and Ennio Salvioni
Charting the Higgs self-coupling boundaries
24 pages, 5 figures. v2: technical problem fixed in Fig 1, otherwise unchanged. v3: minor changes, matches the published version
JHEP 12 (2022) 148
10.1007/JHEP12(2022)148
CERN-TH-2022-140
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Could new physics first manifest itself in Higgs self-coupling measurements? In other words, how large could deviations in the Higgs self-coupling be, if other Higgs and electroweak measurements are compatible with Standard Model predictions? Using theoretical arguments supported by concrete models we derive a bound on the ratio of self-coupling to single-Higgs coupling deviations in ultraviolet completions of the Standard Model where parameters are not fine-tuned. Broadly speaking, a one-loop hierarchy is allowed. We thus stress that self-coupling measurements at the LHC and future colliders probe uncharted parameter space, presenting discovery potential even in the absence of emerging hints in single-Higgs coupling measurements. For instance, if other observables show less than two-sigma deviations by the end of the LHC programme, the Higgs self-coupling deviations could still exceed 200% in the models discussed, without introducing fine-tuning of ultraviolet parameters.
[ { "created": "Thu, 1 Sep 2022 18:00:12 GMT", "version": "v1" }, { "created": "Mon, 5 Sep 2022 17:08:12 GMT", "version": "v2" }, { "created": "Thu, 29 Dec 2022 12:04:09 GMT", "version": "v3" } ]
2023-01-02
[ [ "Durieux", "Gauthier", "" ], [ "McCullough", "Matthew", "" ], [ "Salvioni", "Ennio", "" ] ]
Could new physics first manifest itself in Higgs self-coupling measurements? In other words, how large could deviations in the Higgs self-coupling be, if other Higgs and electroweak measurements are compatible with Standard Model predictions? Using theoretical arguments supported by concrete models we derive a bound on the ratio of self-coupling to single-Higgs coupling deviations in ultraviolet completions of the Standard Model where parameters are not fine-tuned. Broadly speaking, a one-loop hierarchy is allowed. We thus stress that self-coupling measurements at the LHC and future colliders probe uncharted parameter space, presenting discovery potential even in the absence of emerging hints in single-Higgs coupling measurements. For instance, if other observables show less than two-sigma deviations by the end of the LHC programme, the Higgs self-coupling deviations could still exceed 200% in the models discussed, without introducing fine-tuning of ultraviolet parameters.
hep-ph/0004257
Mikhail Voloshin
M.B. Voloshin
Inclusive weak decay rates of heavy hadrons
25 pages, 2 figures. Expanded version of a contribution to the final report book of the Fermilab Workshop on B Physics at Tevatron
null
null
TPI-MINN-00/17, UMN-TH-1851-00
hep-ph
null
A compact review of the theory, including some recent developments, of inclusive weak decay rates of charmed and b hadrons with an emphasis on predictions that can be tested in the forthcoming experiments.
[ { "created": "Thu, 27 Apr 2000 20:43:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Voloshin", "M. B.", "" ] ]
A compact review of the theory, including some recent developments, of inclusive weak decay rates of charmed and b hadrons with an emphasis on predictions that can be tested in the forthcoming experiments.
hep-ph/9506374
null
A. Ali and C. Greub
Photon Energy Spectrum in $B \to X_s \gamma$ and Comparison with Data
16 pages (including 5 Figures as encapsulated ps-files: use epsf and rotate)
Phys.Lett.B361:146-154,1995
10.1016/0370-2693(95)01118-A
DESY 95-117 and SLAC-PUB-95-6940
hep-ph
null
A comparison of the inclusive photon energy spectrum in the radiative decay $\BGAMAXS$, measured recently by the CLEO collaboration, with the standard model is presented, using a $B$-meson wave function model and improving earlier perturbative QCD-based computations of the same. The dependence of the photon energy spectrum on the non-perturbative model parameters, $p_F$, the $b$-quark Fermi momentum in the $B$ hadron, and $m_q$, the spectator quark mass, is explicitly shown, allowing a comparison of these parameters with the ones obtained from the analysis of the lepton energy spectrum in semileptonic $B$ decays. Taking into account present uncertainties, we estimate $\BBGAMAXS = (2.55 \pm 1.28) \times 10^{-4}$ in the standard model, assuming $\absvts/\absvcb= 1.0$. Comparing this with the CLEO measurement $\BBGAMAXS = (2.32 \pm 0.67) \times 10^{-4}$ implies $\absvts/\absvcb= 1.1 \pm 0.43$, in agreement with the CKM unitarity.
[ { "created": "Tue, 20 Jun 1995 14:16:59 GMT", "version": "v1" } ]
2011-01-05
[ [ "Ali", "A.", "" ], [ "Greub", "C.", "" ] ]
A comparison of the inclusive photon energy spectrum in the radiative decay $\BGAMAXS$, measured recently by the CLEO collaboration, with the standard model is presented, using a $B$-meson wave function model and improving earlier perturbative QCD-based computations of the same. The dependence of the photon energy spectrum on the non-perturbative model parameters, $p_F$, the $b$-quark Fermi momentum in the $B$ hadron, and $m_q$, the spectator quark mass, is explicitly shown, allowing a comparison of these parameters with the ones obtained from the analysis of the lepton energy spectrum in semileptonic $B$ decays. Taking into account present uncertainties, we estimate $\BBGAMAXS = (2.55 \pm 1.28) \times 10^{-4}$ in the standard model, assuming $\absvts/\absvcb= 1.0$. Comparing this with the CLEO measurement $\BBGAMAXS = (2.32 \pm 0.67) \times 10^{-4}$ implies $\absvts/\absvcb= 1.1 \pm 0.43$, in agreement with the CKM unitarity.
0708.1659
Jose Antonio Oller
Jose A. Oller, Luis Roca and Carlos Schat
Improved dispersion relations for \gamma\gamma\to \pi^0\pi^0
10 pages, 5 figures. Extended discussion on the width of the sigma to gamma gamma
Phys.Lett.B659:201-208,2008
10.1016/j.physletb.2007.11.030
null
hep-ph
null
We perform a dispersive theoretical study of the reaction \gamma\gamma\to pi^0\pi^0 emphasizing the low energy region. The large source of theoretical uncertainty to calculate the \gamma\gamma\to\pi^0\pi^0 total cross section for \sqrt{s}\gtrsim 0.5 GeV within the dispersive approach is removed. This is accomplished by taking one more subtraction in the dispersion relations, where the extra subtraction constant is fixed by considering new low energy constraints, one of them further refined by taking into consideration the f_0(980) region. This allows us to make sharper predictions for the cross section for \sqrt{s}\lesssim 0.8 GeV, below the onset of D-wave contributions. In this way, were new more precise data on \gamma\gamma\to\pi^0\pi^0 available one might then distinguish between different parameterizations of the \pi\pi isoscalar S-wave. We also elaborate on the width of the \sigma resonance to \gamma\gamma and provide new values.
[ { "created": "Mon, 13 Aug 2007 08:37:35 GMT", "version": "v1" }, { "created": "Tue, 6 Nov 2007 11:10:11 GMT", "version": "v2" } ]
2008-11-26
[ [ "Oller", "Jose A.", "" ], [ "Roca", "Luis", "" ], [ "Schat", "Carlos", "" ] ]
We perform a dispersive theoretical study of the reaction \gamma\gamma\to pi^0\pi^0 emphasizing the low energy region. The large source of theoretical uncertainty to calculate the \gamma\gamma\to\pi^0\pi^0 total cross section for \sqrt{s}\gtrsim 0.5 GeV within the dispersive approach is removed. This is accomplished by taking one more subtraction in the dispersion relations, where the extra subtraction constant is fixed by considering new low energy constraints, one of them further refined by taking into consideration the f_0(980) region. This allows us to make sharper predictions for the cross section for \sqrt{s}\lesssim 0.8 GeV, below the onset of D-wave contributions. In this way, were new more precise data on \gamma\gamma\to\pi^0\pi^0 available one might then distinguish between different parameterizations of the \pi\pi isoscalar S-wave. We also elaborate on the width of the \sigma resonance to \gamma\gamma and provide new values.
1112.3778
Juan Antonio Aguilar-Saavedra
J. A. Aguilar-Saavedra, Jose Santiago
Four tops and the t tbar forward-backward asymmetry
LaTeX 5 pages. Added results for 14 TeV. Final version to appear in PRD
null
10.1103/PhysRevD.85.034021
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New colour octet vectors below the TeV scale could explain the anomalous t tbar forward-backward asymmetry observed at the Tevatron experiments, while being consistent with the current LHC data. These models generally lead to four-top final states at the LHC at observable levels. We compute the four-top production cross section at the LHC in a model with a massive colour octet vector as a function its mass, its width and its coupling to the top quark. Octet masses in the vicinity of the t tbar threshold are generally excluded by present limits on the production of same-sign dileptons and trileptons. Masses above 650 GeV are allowed, quite independently of the couplings, but they can be probed with the luminosity of 5 fb^-1 already collected at the LHC, up to around 800 GeV. The four-top production cross section is increased by a factor ~ 2 with sqrt{s}=8 TeV and by up to almost two orders of magnitude with sqrt{s}=14 TeV, thus greatly increasing the reach for massive gluons after the LHC energy upgrade.
[ { "created": "Fri, 16 Dec 2011 12:22:44 GMT", "version": "v1" }, { "created": "Wed, 25 Jan 2012 16:10:47 GMT", "version": "v2" } ]
2015-06-03
[ [ "Aguilar-Saavedra", "J. A.", "" ], [ "Santiago", "Jose", "" ] ]
New colour octet vectors below the TeV scale could explain the anomalous t tbar forward-backward asymmetry observed at the Tevatron experiments, while being consistent with the current LHC data. These models generally lead to four-top final states at the LHC at observable levels. We compute the four-top production cross section at the LHC in a model with a massive colour octet vector as a function its mass, its width and its coupling to the top quark. Octet masses in the vicinity of the t tbar threshold are generally excluded by present limits on the production of same-sign dileptons and trileptons. Masses above 650 GeV are allowed, quite independently of the couplings, but they can be probed with the luminosity of 5 fb^-1 already collected at the LHC, up to around 800 GeV. The four-top production cross section is increased by a factor ~ 2 with sqrt{s}=8 TeV and by up to almost two orders of magnitude with sqrt{s}=14 TeV, thus greatly increasing the reach for massive gluons after the LHC energy upgrade.
hep-ph/0312118
Jae-hyeon Park
Jae-hyeon Park
B -> phi K_S CP asymmetries as a probe of supersymmetry
6 pages. Talk presented at ICFP2003, KIAS, Seoul, Oct 6-11, 2003
J.Korean Phys.Soc.45:S329-S334,2004
null
KAIST-TH 2003/12
hep-ph
null
We consider sparticle contributions to time dependent CP asymmetry in B -> phi K_S. As for the gluino-squark loop, LR or RL insertion is more likely to give recently observed S_{phi K} < 0 than LL or RR insertion. Neutral Higgs contribution does not change S_{phi K} very much due to the strong constraint from B_s -> mu^+ mu^-. We also show correlations among related processes such as direct CP asymmetry in B -> X_s gamma and B_s - B_s bar mixing, and discuss theoretical motivations for desired strength of flavor violation.
[ { "created": "Tue, 9 Dec 2003 12:18:35 GMT", "version": "v1" } ]
2011-03-23
[ [ "Park", "Jae-hyeon", "" ] ]
We consider sparticle contributions to time dependent CP asymmetry in B -> phi K_S. As for the gluino-squark loop, LR or RL insertion is more likely to give recently observed S_{phi K} < 0 than LL or RR insertion. Neutral Higgs contribution does not change S_{phi K} very much due to the strong constraint from B_s -> mu^+ mu^-. We also show correlations among related processes such as direct CP asymmetry in B -> X_s gamma and B_s - B_s bar mixing, and discuss theoretical motivations for desired strength of flavor violation.
2210.00019
Theo Heimel
Anja Butter, Theo Heimel, Till Martini, Sascha Peitzsch, Tilman Plehn
Two Invertible Networks for the Matrix Element Method
25 pages, 13 figures
SciPost Phys. 15, 094 (2023)
10.21468/SciPostPhys.15.3.094
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The matrix element method is widely considered the ultimate LHC inference tool for small event numbers. We show how a combination of two conditional generative neural networks encodes the QCD radiation and detector effects without any simplifying assumptions, while keeping the computation of likelihoods for individual events numerically efficient. We illustrate our approach for the CP-violating phase of the top Yukawa coupling in associated Higgs and single-top production. Currently, the limiting factor for the precision of our approach is jet combinatorics.
[ { "created": "Fri, 30 Sep 2022 18:00:05 GMT", "version": "v1" }, { "created": "Fri, 21 Oct 2022 10:52:34 GMT", "version": "v2" }, { "created": "Fri, 17 Feb 2023 09:52:55 GMT", "version": "v3" }, { "created": "Wed, 15 Mar 2023 15:30:47 GMT", "version": "v4" }, { "created": "Wed, 21 Jun 2023 15:20:33 GMT", "version": "v5" } ]
2023-09-13
[ [ "Butter", "Anja", "" ], [ "Heimel", "Theo", "" ], [ "Martini", "Till", "" ], [ "Peitzsch", "Sascha", "" ], [ "Plehn", "Tilman", "" ] ]
The matrix element method is widely considered the ultimate LHC inference tool for small event numbers. We show how a combination of two conditional generative neural networks encodes the QCD radiation and detector effects without any simplifying assumptions, while keeping the computation of likelihoods for individual events numerically efficient. We illustrate our approach for the CP-violating phase of the top Yukawa coupling in associated Higgs and single-top production. Currently, the limiting factor for the precision of our approach is jet combinatorics.
1406.4158
Jozef Dudek
Jozef J. Dudek, Robert G. Edwards, Christopher E. Thomas and David J. Wilson
Resonances in coupled {\pi}K,{\eta}K scattering from quantum chromodynamics
V3: version accepted for publication in PRL. A code bug which led to incorrect normalization of certain correlation functions is corrected - qualitative features of the results remain unchanged
Phys. Rev. Lett. 113, 182001 (2014)
10.1103/PhysRevLett.113.182001
JLAB-THY-14-1891, DAMTP-2014-36
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using first-principles calculation within Quantum Chromodynamics, we are able to determine a pattern of strangeness=1 resonances which appear as complex singularities within coupled $\pi K$, $\eta K$ scattering amplitudes. We make use of numerical computation in the lattice discretized approach to the quantum field theory with light quark masses corresponding to $m_\pi \sim 400\, \textrm{MeV}$ and at a single lattice spacing. The energy dependence of scattering amplitudes is extracted through their relationship to the discrete spectrum in a finite-volume, which we map out in unprecedented detail.
[ { "created": "Mon, 16 Jun 2014 20:13:28 GMT", "version": "v1" }, { "created": "Tue, 24 Jun 2014 12:51:28 GMT", "version": "v2" }, { "created": "Thu, 23 Oct 2014 15:37:52 GMT", "version": "v3" } ]
2014-11-05
[ [ "Dudek", "Jozef J.", "" ], [ "Edwards", "Robert G.", "" ], [ "Thomas", "Christopher E.", "" ], [ "Wilson", "David J.", "" ] ]
Using first-principles calculation within Quantum Chromodynamics, we are able to determine a pattern of strangeness=1 resonances which appear as complex singularities within coupled $\pi K$, $\eta K$ scattering amplitudes. We make use of numerical computation in the lattice discretized approach to the quantum field theory with light quark masses corresponding to $m_\pi \sim 400\, \textrm{MeV}$ and at a single lattice spacing. The energy dependence of scattering amplitudes is extracted through their relationship to the discrete spectrum in a finite-volume, which we map out in unprecedented detail.
hep-ph/0309219
Zoltan Ligeti
Zoltan Ligeti
|Vcb| and |Vub|: Theoretical Developments
Invited talk at Flavor Physics & CP Violation (FPCP 2003), Ecole Polytechnique, Paris, France, 3-6 June 2003; 12 pages
null
null
LBNL-53298
hep-ph
null
The determinations of |Vcb| and |Vub| from semileptonic B decays are reviewed with a critical discussion of the theoretical uncertainties and concentrating on recent developments. Future prospects and limitations are also discussed.
[ { "created": "Thu, 18 Sep 2003 19:45:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ligeti", "Zoltan", "" ] ]
The determinations of |Vcb| and |Vub| from semileptonic B decays are reviewed with a critical discussion of the theoretical uncertainties and concentrating on recent developments. Future prospects and limitations are also discussed.
1312.2591
Jamie Tattersall Dr
Manuel Drees, Herbi Dreiner, Jong Soo Kim, Daniel Schmeier, Jamie Tattersall
CheckMATE: Confronting your Favourite New Physics Model with LHC Data
Version submitted to CPC. Updated versions of this manual will now be available at: http://www.hepforge.org/downloads/checkmate
null
null
ADP-13-29/T849 IFT-UAM/CSIC-13-133
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the first three years of running, the LHC has delivered a wealth of new data that is now being analysed. With over 20 fb$^{-1}$ of integrated luminosity, both ATLAS and CMS have performed many searches for new physics that theorists are eager to test their model against. However, tuning the detector simulations, understanding the particular analysis details and interpreting the results can be a tedious task. CheckMATE (Check Models At Terascale Energies) is a program package which accepts simulated event files in many formats for any model. The program then determines whether the model is excluded or not at 95% C.L. by comparing to many recent experimental analyses. Furthermore the program can calculate confidence limits and provide detailed information about signal regions of interest. It is simple to use and the program structure allows for easy extensions to upcoming LHC results in the future. CheckMATE can be found at: http://checkmate.hepforge.org
[ { "created": "Mon, 9 Dec 2013 21:00:06 GMT", "version": "v1" }, { "created": "Tue, 28 Jan 2014 10:01:00 GMT", "version": "v2" } ]
2014-01-29
[ [ "Drees", "Manuel", "" ], [ "Dreiner", "Herbi", "" ], [ "Kim", "Jong Soo", "" ], [ "Schmeier", "Daniel", "" ], [ "Tattersall", "Jamie", "" ] ]
In the first three years of running, the LHC has delivered a wealth of new data that is now being analysed. With over 20 fb$^{-1}$ of integrated luminosity, both ATLAS and CMS have performed many searches for new physics that theorists are eager to test their model against. However, tuning the detector simulations, understanding the particular analysis details and interpreting the results can be a tedious task. CheckMATE (Check Models At Terascale Energies) is a program package which accepts simulated event files in many formats for any model. The program then determines whether the model is excluded or not at 95% C.L. by comparing to many recent experimental analyses. Furthermore the program can calculate confidence limits and provide detailed information about signal regions of interest. It is simple to use and the program structure allows for easy extensions to upcoming LHC results in the future. CheckMATE can be found at: http://checkmate.hepforge.org
1111.3547
Yoshitaka Hatta
Yoshitaka Hatta
Notes on the orbital angular momentum of quarks in the nucleon
11 pages; v2. added comments and references on the Wigner distribution approach; v3. improved presentation, to appear in Phys.Lett.B
null
10.1016/j.physletb.2012.01.024
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the orbital angular momentum of partons inside a longitudinally polarized proton in the recently proposed framework of spin decomposition. The quark orbital angular momentum defined by Ji can be decomposed into the `canonical' and the `potential' angular momentum parts, both of which are represented as the matrix element of a manifestly gauge invariant operator.
[ { "created": "Tue, 15 Nov 2011 15:06:41 GMT", "version": "v1" }, { "created": "Wed, 23 Nov 2011 05:56:20 GMT", "version": "v2" }, { "created": "Tue, 24 Jan 2012 08:05:14 GMT", "version": "v3" } ]
2015-06-03
[ [ "Hatta", "Yoshitaka", "" ] ]
We discuss the orbital angular momentum of partons inside a longitudinally polarized proton in the recently proposed framework of spin decomposition. The quark orbital angular momentum defined by Ji can be decomposed into the `canonical' and the `potential' angular momentum parts, both of which are represented as the matrix element of a manifestly gauge invariant operator.
1307.6218
Ricardo Gonzalez Felipe
Sacha Davidson, Ricardo Gonzalez Felipe, H. Serodio, Joao P. Silva
Baryogenesis through split Higgsogenesis
21 pages, 2 figures
null
10.1007/JHEP11(2013)100
CFTP/13-017
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the cosmological evolution of asymmetries in the two-Higgs doublet extension of the Standard Model, prior to the electroweak phase transition. If Higgs flavour-exchanging interactions are sufficiently slow, then a relative asymmetry among the Higgs doublets corresponds to an effectively conserved quantum number. Since the magnitude of the Higgs couplings depends on the choice of basis in the Higgs doublet space, we attempt to formulate basis-independent out-of-equilibrium conditions. We show that an initial asymmetry between the Higgs scalars, which could be generated by CP violation in the Higgs sector, will be transformed into a baryon asymmetry by the sphalerons, without the need of $B-L$ violation. This novel mechanism of baryogenesis through (split) Higgsogenesis is exemplified with simple scenarios based on the out-of-equilibrium decay of heavy singlet scalar fields into the Higgs doublets.
[ { "created": "Tue, 23 Jul 2013 20:00:12 GMT", "version": "v1" } ]
2015-06-16
[ [ "Davidson", "Sacha", "" ], [ "Felipe", "Ricardo Gonzalez", "" ], [ "Serodio", "H.", "" ], [ "Silva", "Joao P.", "" ] ]
We study the cosmological evolution of asymmetries in the two-Higgs doublet extension of the Standard Model, prior to the electroweak phase transition. If Higgs flavour-exchanging interactions are sufficiently slow, then a relative asymmetry among the Higgs doublets corresponds to an effectively conserved quantum number. Since the magnitude of the Higgs couplings depends on the choice of basis in the Higgs doublet space, we attempt to formulate basis-independent out-of-equilibrium conditions. We show that an initial asymmetry between the Higgs scalars, which could be generated by CP violation in the Higgs sector, will be transformed into a baryon asymmetry by the sphalerons, without the need of $B-L$ violation. This novel mechanism of baryogenesis through (split) Higgsogenesis is exemplified with simple scenarios based on the out-of-equilibrium decay of heavy singlet scalar fields into the Higgs doublets.
1308.4513
Jason Kumar
Jason Kumar
Asymmetric Dark Matter
8 pages, 1 figure, LaTeX. Submitted to the proceedings of PPC 2013. v2 and v3: typos fixed and references corrected
null
10.1063/1.4883455
UH-511-1217-2013
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the theoretical framework underlying models of asymmetric dark matter, describe astrophysical constraints which arise from observations of neutron stars, and discuss the prospects for detecting asymmetric dark matter.
[ { "created": "Wed, 21 Aug 2013 08:50:56 GMT", "version": "v1" }, { "created": "Sat, 24 Aug 2013 17:36:53 GMT", "version": "v2" }, { "created": "Tue, 17 Sep 2013 00:33:03 GMT", "version": "v3" } ]
2015-06-16
[ [ "Kumar", "Jason", "" ] ]
We review the theoretical framework underlying models of asymmetric dark matter, describe astrophysical constraints which arise from observations of neutron stars, and discuss the prospects for detecting asymmetric dark matter.
1309.4688
Adam Smetana
Adam Smetana
Electroweak symmetry breaking by dynamically generated masses of quarks and leptons
doctoral thesis
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aim of the thesis is to study models of the electroweak symmetry breaking caused by dynamically generated masses of quarks and leptons. (1) We perform the basic analysis whether the main underlying idea, that the masses of only known fermions can provide the electroweak symmetry breaking, is actually feasible. For that we elaborate a two-composite-Higgs-doublet model of the top-quark and neutrino condensation. The model suggests rather large number, $\mathcal{O}(100)$, of right-handed neutrinos. (2) We analyze the model of strong Yukawa dynamics where the dynamical fermion mass generation is provided by exchanges of new elementary massive complex doublet scalar fields. We focus on solving the coupled Schwinger--Dyson equations for fermion and scalar self-energies by means of approximative methods. We document that strongly hierarchical mass spectra can be reproduced. (3) We elaborate the flavor gauge model where the dynamical fermion mass generation is provided by asymptotically free non-Abelian self-breaking flavor gauge dynamics. We show that the Majorana type condensation of right-handed neutrinos in the flavor sextet representation triggers the complete flavor symmetry breaking. It leads to huge right-handed neutrino Majorana masses.
[ { "created": "Wed, 18 Sep 2013 15:58:59 GMT", "version": "v1" } ]
2013-09-19
[ [ "Smetana", "Adam", "" ] ]
The aim of the thesis is to study models of the electroweak symmetry breaking caused by dynamically generated masses of quarks and leptons. (1) We perform the basic analysis whether the main underlying idea, that the masses of only known fermions can provide the electroweak symmetry breaking, is actually feasible. For that we elaborate a two-composite-Higgs-doublet model of the top-quark and neutrino condensation. The model suggests rather large number, $\mathcal{O}(100)$, of right-handed neutrinos. (2) We analyze the model of strong Yukawa dynamics where the dynamical fermion mass generation is provided by exchanges of new elementary massive complex doublet scalar fields. We focus on solving the coupled Schwinger--Dyson equations for fermion and scalar self-energies by means of approximative methods. We document that strongly hierarchical mass spectra can be reproduced. (3) We elaborate the flavor gauge model where the dynamical fermion mass generation is provided by asymptotically free non-Abelian self-breaking flavor gauge dynamics. We show that the Majorana type condensation of right-handed neutrinos in the flavor sextet representation triggers the complete flavor symmetry breaking. It leads to huge right-handed neutrino Majorana masses.
1506.00121
Yi Jin
Y. Jin, H. L. Li, S. Q. Li, S. Y. Li, Z. G. Si, T. Yao, and X. F. Zhang
Studying color connection effects of $e^+e^- \to c\bar{c}c\bar{c} \to \Xi_{cc}+X $ process within Quark Combination Model
4 pages, 7 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
The color connection of the parton system is an important bridge to connect the perturbative process and the hadronization one. The special color connection of four-heavy-quark system in $e^+e^-$ annihilation, which is the necessary one for the doubly heavy baryon and tetraquark productions is revisited. The hadronization effects, investigated with the help of the Quark Combination Model are compared with the corresponding results employing the Lund String Model in our previous work. The global properties related to a certain color connection are not sensitive to various hadronization models.
[ { "created": "Sat, 30 May 2015 14:28:03 GMT", "version": "v1" }, { "created": "Fri, 5 Jun 2015 06:27:43 GMT", "version": "v2" } ]
2015-06-08
[ [ "Jin", "Y.", "" ], [ "Li", "H. L.", "" ], [ "Li", "S. Q.", "" ], [ "Li", "S. Y.", "" ], [ "Si", "Z. G.", "" ], [ "Yao", "T.", "" ], [ "Zhang", "X. F.", "" ] ]
The color connection of the parton system is an important bridge to connect the perturbative process and the hadronization one. The special color connection of four-heavy-quark system in $e^+e^-$ annihilation, which is the necessary one for the doubly heavy baryon and tetraquark productions is revisited. The hadronization effects, investigated with the help of the Quark Combination Model are compared with the corresponding results employing the Lund String Model in our previous work. The global properties related to a certain color connection are not sensitive to various hadronization models.
hep-ph/9701223
Wojciech Florkowski
Wojciech Florkowski
Description of hot compressed hadronic matter based on an effective chiral lagrangian
128 pages (35 figures), Latex, uses psfig
Acta Phys.Polon. B28 (1997) 2079-2205
null
INP 1739/PH
hep-ph
null
A review of the recent results obtained in the Nambu -- Jona-Lasinio model is given. In particular, the effect of screening of meson fields at finite temperature or density is analyzed and the formulation of a chirally invariant transport theory for quark matter is presented.
[ { "created": "Mon, 6 Jan 1997 11:28:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Florkowski", "Wojciech", "" ] ]
A review of the recent results obtained in the Nambu -- Jona-Lasinio model is given. In particular, the effect of screening of meson fields at finite temperature or density is analyzed and the formulation of a chirally invariant transport theory for quark matter is presented.
0705.3472
Sushil Singh Chauhan
Satyaki Bhattacharya, Sushil S. Chauhan, Brajesh C. Choudhary, Debajyoti Choudhury
Search for Excited Quarks in $q\bar{q} \to \gamma\gamma$ at the LHC
11 pages, 11 figures
Phys.Rev.D76:115017,2007
10.1103/PhysRevD.76.115017
null
hep-ph
null
If quarks are composite particles, then excited states are expected to play a r\^ole in the Large Hadron Collider phenomena. Concentrating on virtual effects, and using a large part of the CMS detection criteria, we present here a realistic examination of their effect in diphoton production at the LHC. For various luminosities, we present the 99 % confidence limit (CL) achievable in $\Lambda-M_{q*}$ parameter space where $\Lambda$ is the compositeness scale and M_{q^*} the mass of the state. For a q^* of mass 0.5 TeV, $\Lambda \leq 1.55 (2.95)$ can be excluded at 99% CL with 30 (200)${\rm fb}^{-1}$ integrated luminosity.
[ { "created": "Wed, 23 May 2007 23:45:07 GMT", "version": "v1" }, { "created": "Sat, 28 Jul 2007 11:50:11 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bhattacharya", "Satyaki", "" ], [ "Chauhan", "Sushil S.", "" ], [ "Choudhary", "Brajesh C.", "" ], [ "Choudhury", "Debajyoti", "" ] ]
If quarks are composite particles, then excited states are expected to play a r\^ole in the Large Hadron Collider phenomena. Concentrating on virtual effects, and using a large part of the CMS detection criteria, we present here a realistic examination of their effect in diphoton production at the LHC. For various luminosities, we present the 99 % confidence limit (CL) achievable in $\Lambda-M_{q*}$ parameter space where $\Lambda$ is the compositeness scale and M_{q^*} the mass of the state. For a q^* of mass 0.5 TeV, $\Lambda \leq 1.55 (2.95)$ can be excluded at 99% CL with 30 (200)${\rm fb}^{-1}$ integrated luminosity.
hep-ph/0607178
Li Tong
Xiao-Gang He, Tong Li, Xue-Qian Li and Yu-Ming Wang
Calculation of BR($\bar{B}^0\to \Lambda_{c}^++\bar p)$ in the PQCD Approach
45 pages, 4 figure and 4 tables. New version replaced
Phys.Rev.D75:034011,2007
10.1103/PhysRevD.75.034011
null
hep-ph
null
We calculate the branching ratio of $\bar{B}^0 \to \Lambda_c^+ \bar{p}$ in the PQCD approach. Most previous model calculations obtained branching ratios significantly larger than experimental data. We find that the predicted branching ratio for BR$(\bar{B}^0 \to \Lambda_c^+ \bar{p})$ in the PQCD approach can vary over a range of $(2.3\sim 5.1)\times 10^{-5}$ with the largest uncertainty coming from the parameters in the wave function of $\Lambda_c$. With the favored values for the parameters in the $\Lambda_c^+$ wave function, $\beta = 1$ GeV and $m_q = 0.3$ GeV, the branching ratio is about $2.3\times 10^{-5}$ which is satisfactorily consistent with the value measured by experiments.
[ { "created": "Sun, 16 Jul 2006 00:48:20 GMT", "version": "v1" }, { "created": "Fri, 20 Oct 2006 15:02:49 GMT", "version": "v2" } ]
2008-11-26
[ [ "He", "Xiao-Gang", "" ], [ "Li", "Tong", "" ], [ "Li", "Xue-Qian", "" ], [ "Wang", "Yu-Ming", "" ] ]
We calculate the branching ratio of $\bar{B}^0 \to \Lambda_c^+ \bar{p}$ in the PQCD approach. Most previous model calculations obtained branching ratios significantly larger than experimental data. We find that the predicted branching ratio for BR$(\bar{B}^0 \to \Lambda_c^+ \bar{p})$ in the PQCD approach can vary over a range of $(2.3\sim 5.1)\times 10^{-5}$ with the largest uncertainty coming from the parameters in the wave function of $\Lambda_c$. With the favored values for the parameters in the $\Lambda_c^+$ wave function, $\beta = 1$ GeV and $m_q = 0.3$ GeV, the branching ratio is about $2.3\times 10^{-5}$ which is satisfactorily consistent with the value measured by experiments.
1607.07056
Mike Berger
M.S. Berger
Lorentz and CPT Violation in Heavy Quark Physics
4 pages, no figures, Presented at the Seventh Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 20-24, 2016
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Violations of the Lorentz and CPT symmetries can appear as observable effects in the direct production of top quarks and their subsequent decays. Earlier results for the $q\bar{q}$ production process for $t\bar{t}$ pairs have been extended to include the gluon fusion process which dominates at the LHC. In addition results are obtained for testing CPT symmetry through single top quark production.
[ { "created": "Sun, 24 Jul 2016 15:36:30 GMT", "version": "v1" } ]
2016-07-26
[ [ "Berger", "M. S.", "" ] ]
Violations of the Lorentz and CPT symmetries can appear as observable effects in the direct production of top quarks and their subsequent decays. Earlier results for the $q\bar{q}$ production process for $t\bar{t}$ pairs have been extended to include the gluon fusion process which dominates at the LHC. In addition results are obtained for testing CPT symmetry through single top quark production.
1304.3468
Joao Silva
R. Gonzalez Felipe, H. Serodio, and Joao P. Silva
Neutrino masses and mixing in A4 models with three Higgs doublets
10 pages, RevTex, 3 figures. v2: much expanded section on softly broken A4; refs added
Phys.Rev. D 88 (2013) 015015
10.1103/PhysRevD.88.015015
CFTP/13-011
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study neutrino masses and mixing in the context of flavor models with A4 symmetry, three scalar doublets in the triplet representation, and three lepton families. We show that there is no representation assignment that yields a dimension-five mass operator consistent with experiment. We then consider a type-I seesaw with three heavy right-handed neutrinos, explaining in detail why it fails, and showing with a numerical example that agreement with the present neutrino oscillation data can be recovered with the inclusion of dimension-three heavy neutrino mass terms that break softly the A4 symmetry.
[ { "created": "Thu, 11 Apr 2013 20:03:02 GMT", "version": "v1" }, { "created": "Thu, 4 Jul 2013 21:06:16 GMT", "version": "v2" } ]
2013-09-10
[ [ "Felipe", "R. Gonzalez", "" ], [ "Serodio", "H.", "" ], [ "Silva", "Joao P.", "" ] ]
We study neutrino masses and mixing in the context of flavor models with A4 symmetry, three scalar doublets in the triplet representation, and three lepton families. We show that there is no representation assignment that yields a dimension-five mass operator consistent with experiment. We then consider a type-I seesaw with three heavy right-handed neutrinos, explaining in detail why it fails, and showing with a numerical example that agreement with the present neutrino oscillation data can be recovered with the inclusion of dimension-three heavy neutrino mass terms that break softly the A4 symmetry.
2004.05398
Alexander Berezhnoy
A. V. Berezhnoy and A. S. Gerasimov
Pentaquarks with a hidden flavour and the hypothesis of the intrinsic charm of the proton
9 pages, 2 figures new version: several references added, text improved according referee's recommendation, quark distribution for pentaquark with hidden strangeness obtained, accepted by Physics of Atomic Nuclei
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the experimental data on pentaquarks with a hidden charm, new upper limits on the intrinsic charm in the proton are obtained, possible shapes of heavy quark distributions inside the proton are discussed.
[ { "created": "Sat, 11 Apr 2020 13:21:26 GMT", "version": "v1" }, { "created": "Sat, 29 Aug 2020 07:24:40 GMT", "version": "v2" } ]
2020-09-01
[ [ "Berezhnoy", "A. V.", "" ], [ "Gerasimov", "A. S.", "" ] ]
Using the experimental data on pentaquarks with a hidden charm, new upper limits on the intrinsic charm in the proton are obtained, possible shapes of heavy quark distributions inside the proton are discussed.
hep-ph/0209219
Massimo Passera
A. Ferroglia, G. Passarino, M. Passera and S. Uccirati
All-Purpose Numerical Evaluation of One-Loop Multi-Leg Feynman Diagrams
56 pages
Nucl.Phys.B650:162-228,2003
10.1016/S0550-3213(02)01070-2
null
hep-ph
null
A detailed investigation is presented of a set of algorithms which form the basis for a fast and reliable numerical integration of one-loop multi-leg (up to six) Feynman diagrams, with special attention to the behavior around (possibly) singular points in phase space. No particular restriction is imposed on kinematics, and complex masses (poles) are allowed.
[ { "created": "Thu, 19 Sep 2002 15:13:57 GMT", "version": "v1" } ]
2011-05-05
[ [ "Ferroglia", "A.", "" ], [ "Passarino", "G.", "" ], [ "Passera", "M.", "" ], [ "Uccirati", "S.", "" ] ]
A detailed investigation is presented of a set of algorithms which form the basis for a fast and reliable numerical integration of one-loop multi-leg (up to six) Feynman diagrams, with special attention to the behavior around (possibly) singular points in phase space. No particular restriction is imposed on kinematics, and complex masses (poles) are allowed.
0908.0915
James Maxin
James A. Maxin, Van E. Mayes, and D.V. Nanopoulos
The Search for a Realistic String Model at LHC
35 pages, 4 figures, accepted for publication in PRD
Phys.Rev.D81:015008,2010
10.1103/PhysRevD.81.015008
null
hep-ph astro-ph.CO hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We survey the low-energy supersymmetry phenomenology of a three-family Pati-Salam model constructed from intersecting D6-branes in Type IIA string theory on the T^6/(Z_2 x Z_2) orientifold which possesses many of the phenomenological properties desired in string model-building. In the model, there is no exotic matter in the low-energy spectrum, the correct mass hierarchies for quarks and leptons may be obtained, and the gauge couplings are automatically unified at the string scale. We calculate the supersymmetry breaking soft terms and the corresponding low-energy supersymmetry particle spectra for the model. We find the WMAP constrained dark matter density can be generated in this model in the stau-neutralino and chargino-neutralino coannihilation regions, with expected final states at LHC consisting of low energy leptons and O(GeV) neutrinos. Moreover, we expect final states in the supercritical string cosmology (SSC) scenario to comprise high energy leptons and O(GeV) neutrinos.
[ { "created": "Thu, 6 Aug 2009 17:21:49 GMT", "version": "v1" }, { "created": "Mon, 14 Dec 2009 15:24:48 GMT", "version": "v2" } ]
2010-01-12
[ [ "Maxin", "James A.", "" ], [ "Mayes", "Van E.", "" ], [ "Nanopoulos", "D. V.", "" ] ]
We survey the low-energy supersymmetry phenomenology of a three-family Pati-Salam model constructed from intersecting D6-branes in Type IIA string theory on the T^6/(Z_2 x Z_2) orientifold which possesses many of the phenomenological properties desired in string model-building. In the model, there is no exotic matter in the low-energy spectrum, the correct mass hierarchies for quarks and leptons may be obtained, and the gauge couplings are automatically unified at the string scale. We calculate the supersymmetry breaking soft terms and the corresponding low-energy supersymmetry particle spectra for the model. We find the WMAP constrained dark matter density can be generated in this model in the stau-neutralino and chargino-neutralino coannihilation regions, with expected final states at LHC consisting of low energy leptons and O(GeV) neutrinos. Moreover, we expect final states in the supercritical string cosmology (SSC) scenario to comprise high energy leptons and O(GeV) neutrinos.
hep-ph/9809437
Ignazio Scimemi
Roberto Contino and Ignazio Scimemi (Dip. di Fisica, Universita' degli Studi di Roma ``La Sapienza'' and INFN, Sezione di Roma, Roma, Italy)
The Supersymmetric Flavor Problem for Heavy First-Two Generation Scalars at Next-to-Leading Order
22 Latex pages, 5 figures; Figs. 1,2 redrawn for K=0.22, section 4.1 revisited, references corrected. Submitted to European Journal of Physics C
Eur.Phys.J.C10:347-356,1999
10.1007/s100520050597
ROME1-1216/98
hep-ph
null
We analyze in detail the constraints on SUSY-model parameters obtained from K-Kbar mixing in the hypothesis of a splitted SUSY spectrum. FCNC contributions from gluino-squark-quark interactions are studied in the so-called mass insertion approximation. We present boundaries on mass insertions and on SUSY mass scales. We improve previous results by including the NLO-QCD corrections to Delta S=2 effective Hamiltonian and the complete set of B-parameters for the evaluation of hadronic matrix elements. A full set of magic-numbers, that can be used for further analyses of these models, is also given. We find that the inclusion of NLO-QCD corrections and the B-parameters change the results obtained at LO and in the Vacuum Insertion Approximation by an amount of about 25-35%.
[ { "created": "Thu, 17 Sep 1998 16:38:02 GMT", "version": "v1" }, { "created": "Sun, 28 Feb 1999 13:27:52 GMT", "version": "v2" } ]
2011-09-13
[ [ "Contino", "Roberto", "", "Dip. di Fisica, Universita' degli\n Studi di Roma ``La Sapienza'' and INFN, Sezione di Roma, Roma, Italy" ], [ "Scimemi", "Ignazio", "", "Dip. di Fisica, Universita' degli\n Studi di Roma ``La Sapienza'' and INFN, Sezione di Roma, Roma, Italy" ] ]
We analyze in detail the constraints on SUSY-model parameters obtained from K-Kbar mixing in the hypothesis of a splitted SUSY spectrum. FCNC contributions from gluino-squark-quark interactions are studied in the so-called mass insertion approximation. We present boundaries on mass insertions and on SUSY mass scales. We improve previous results by including the NLO-QCD corrections to Delta S=2 effective Hamiltonian and the complete set of B-parameters for the evaluation of hadronic matrix elements. A full set of magic-numbers, that can be used for further analyses of these models, is also given. We find that the inclusion of NLO-QCD corrections and the B-parameters change the results obtained at LO and in the Vacuum Insertion Approximation by an amount of about 25-35%.
2401.14017
Steven D. Bass
Steven D. Bass
Spinning protons and gluons in the $\eta'$
14 pages, in memory of Harald Fritzsch, contribution to the WSPC book edited by G. Buchalla, D. L\"ust and Z.-Z. Xing
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The proton spin puzzle has inspired a vast programme of experiments and theoretical work challenging our understanding of QCD and its role in the structure of hadrons.The proton's internal spin structure is connected to chiral symmetry and, through gluon degrees of freedom in the flavour singlet channel, to the physics of the $\eta'$ meson. Why do quarks contribute just about one third of the proton's spin? Why are $\eta'$ mesons and their interactions so sensitive to gluonic degrees of freedom? We review the status of these topics and some key observables for forthcoming experiments.
[ { "created": "Thu, 25 Jan 2024 08:51:11 GMT", "version": "v1" } ]
2024-01-26
[ [ "Bass", "Steven D.", "" ] ]
The proton spin puzzle has inspired a vast programme of experiments and theoretical work challenging our understanding of QCD and its role in the structure of hadrons.The proton's internal spin structure is connected to chiral symmetry and, through gluon degrees of freedom in the flavour singlet channel, to the physics of the $\eta'$ meson. Why do quarks contribute just about one third of the proton's spin? Why are $\eta'$ mesons and their interactions so sensitive to gluonic degrees of freedom? We review the status of these topics and some key observables for forthcoming experiments.
hep-ph/0206024
David Rainwater
Uli Baur (SUNY-Buffalo), Tilman Plehn (UW-Madison) and David Rainwater (Fermilab)
Measuring the Higgs Boson Self Coupling at the LHC and Finite Top Mass Matrix Elements
4 pages, 4 embedded EPS figs, submitted to PRL
Phys.Rev.Lett.89:151801,2002
10.1103/PhysRevLett.89.151801
UB-HET-02-03, MADPH-02-1271, FERMILAB-Pub-02/092-T
hep-ph
null
Inclusive Standard Model Higgs boson pair production and subsequent decay to same-sign dileptons via weak gauge W bosons at the CERN Large Hadron Collider has the capability to determine the Higgs boson self-coupling, lambda. The large top quark mass limit is found not to be a good approximation for the signal if one wishes to utilize differential distributions in the analysis. We find that it should be possible at the LHC with design luminosity to establish that the Standard Model Higgs boson has a non-zero self-coupling and that lambda/lambda(SM) can be restricted to a range of 0--3.7 at 95% confidence level if its mass is between 150 and 200 GeV.
[ { "created": "Mon, 3 Jun 2002 22:51:13 GMT", "version": "v1" } ]
2014-11-17
[ [ "Baur", "Uli", "", "SUNY-Buffalo" ], [ "Plehn", "Tilman", "", "UW-Madison" ], [ "Rainwater", "David", "", "Fermilab" ] ]
Inclusive Standard Model Higgs boson pair production and subsequent decay to same-sign dileptons via weak gauge W bosons at the CERN Large Hadron Collider has the capability to determine the Higgs boson self-coupling, lambda. The large top quark mass limit is found not to be a good approximation for the signal if one wishes to utilize differential distributions in the analysis. We find that it should be possible at the LHC with design luminosity to establish that the Standard Model Higgs boson has a non-zero self-coupling and that lambda/lambda(SM) can be restricted to a range of 0--3.7 at 95% confidence level if its mass is between 150 and 200 GeV.
hep-ph/9807492
Geoffrey Bodwin
Geoffrey T. Bodwin (Argonne), Yu-Qi Chen (Ohio State)
Renormalon Ambiguities in NRQCD Operator Matrix Elements
29 pages, REVTEX; revised Abstract, Introduction, Summary, corrected some typos
Phys. Rev. D 60, 054008 (1999)
10.1103/PhysRevD.60.054008
ANL-HEP-PR-98-29, OHSTPY-HEP-T-98-008
hep-ph hep-lat hep-th
null
We analyze the renormalon ambiguities that appear in factorization formulas in QCD. Our analysis contains a simple argument that the ambiguities in the short-distance coefficients and operator matrix elements are artifacts of dimensional-regularization factorization schemes and are absent in cutoff schemes. We also present a method for computing the renormalon ambiguities in operator matrix elements and apply it to a computation of the ambiguities in the matrix elements that appear in the NRQCD factorization formulas for the annihilation decays of S-wave quarkonia. Our results, combined with those of Braaten and Chen for the short-distance coefficients, provide an explicit demonstration that the ambiguities cancel in the physical decay rates. In addition, we analyze the renormalon ambiguities in the Gremm-Kapustin relation and in various definitions of the heavy-quark mass.
[ { "created": "Fri, 24 Jul 1998 22:45:02 GMT", "version": "v1" }, { "created": "Thu, 3 Jun 1999 18:59:23 GMT", "version": "v2" } ]
2016-08-25
[ [ "Bodwin", "Geoffrey T.", "", "Argonne" ], [ "Chen", "Yu-Qi", "", "Ohio State" ] ]
We analyze the renormalon ambiguities that appear in factorization formulas in QCD. Our analysis contains a simple argument that the ambiguities in the short-distance coefficients and operator matrix elements are artifacts of dimensional-regularization factorization schemes and are absent in cutoff schemes. We also present a method for computing the renormalon ambiguities in operator matrix elements and apply it to a computation of the ambiguities in the matrix elements that appear in the NRQCD factorization formulas for the annihilation decays of S-wave quarkonia. Our results, combined with those of Braaten and Chen for the short-distance coefficients, provide an explicit demonstration that the ambiguities cancel in the physical decay rates. In addition, we analyze the renormalon ambiguities in the Gremm-Kapustin relation and in various definitions of the heavy-quark mass.
1503.03534
Chiu Man Ho
Chiu Man Ho and Robert J. Scherrer
Cosmological Particle Decays at Finite Temperature
21 pages, 5 figures, v2: version to appear in PRD
Phys. Rev. D 92, 025019 (2015)
10.1103/PhysRevD.92.025019
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate finite-temperature corrections to the decay rate of a generic neutral (pseudo)scalar particle that decays into (pseudo)scalars or fermion-antifermion pairs. The ratio of the finite-temperature decay rate to the zero-temperature decay rate is presented. Thermal effects are largest in the limit where the decaying particle is nonrelativistic but with a mass well below the background temperature, but significant effects are possible even when we relax the former assumption. Thermal effects are reduced for the case of nonzero momentum of the decaying particle. We discuss cosmological scenarios under which significant finite-temperature corrections to the decay rate can be achieved.
[ { "created": "Wed, 11 Mar 2015 23:34:21 GMT", "version": "v1" }, { "created": "Thu, 2 Jul 2015 15:57:05 GMT", "version": "v2" } ]
2015-08-06
[ [ "Ho", "Chiu Man", "" ], [ "Scherrer", "Robert J.", "" ] ]
We calculate finite-temperature corrections to the decay rate of a generic neutral (pseudo)scalar particle that decays into (pseudo)scalars or fermion-antifermion pairs. The ratio of the finite-temperature decay rate to the zero-temperature decay rate is presented. Thermal effects are largest in the limit where the decaying particle is nonrelativistic but with a mass well below the background temperature, but significant effects are possible even when we relax the former assumption. Thermal effects are reduced for the case of nonzero momentum of the decaying particle. We discuss cosmological scenarios under which significant finite-temperature corrections to the decay rate can be achieved.
hep-ph/0409125
Nikolai Uraltsev
Nikolai Uraltsev
Heavy quark expansion in beauty: recent successes and problems
13 pages, LaTeX, five figures. Invited talk at "Continuous Advances in QCD 2004, 13-16 May 2004, Minneapolis, MN USA; to appear in the Proceedings
null
10.1142/9789812702326_0009
Bicocca-FT-04-12, UND-HEP-04-BIG07
hep-ph
null
The status of the QCD-based heavy quark expansion is briefly reviewed. A good agreement between properly applied theory and new precision data is observed. Critical remarks on certain recent claims from HQET are presented. Recent applications to the exclusive heavy flavor transitions are addressed. The `1/2 > 3/2' problem for the transitions into the charm P-wave states is discussed.
[ { "created": "Fri, 10 Sep 2004 20:00:49 GMT", "version": "v1" } ]
2017-08-23
[ [ "Uraltsev", "Nikolai", "" ] ]
The status of the QCD-based heavy quark expansion is briefly reviewed. A good agreement between properly applied theory and new precision data is observed. Critical remarks on certain recent claims from HQET are presented. Recent applications to the exclusive heavy flavor transitions are addressed. The `1/2 > 3/2' problem for the transitions into the charm P-wave states is discussed.
2210.03126
Zamir Heller-Algazi
Michael Geller and Zamir Heller-Algazi
Boosting Asymmetric Charged DM via Thermalization
26 pages, 8 figures
null
10.1007/JHEP03(2023)184
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a dark sector scenario with two dark matter species with opposite dark $U(1)$ charges and an asymmetric population comprising some fraction of the dark matter abundance. A new mechanism for boosting dark matter is introduced, arising from the large mass hierarchy between the two particles. In the galaxy, the two species thermalize efficiently through dark Rutherford scattering greatly boosting the lighter dark matter particle, far above the virial and escape velocities in the galaxy, while the dark charge prevents it from escaping. We study the consequences of this scenario for direct-detection experiments, assuming a kinetic mixing between the dark photon and the photon. If the charged dark sector makes up 5% of the total DM mass in our galaxy and the mass ratio is between $10^3-10^4$, we find that current and future experiments may probe the boosted light dark matter for masses down to 100 keV, in a hitherto unexplored parameter range.
[ { "created": "Thu, 6 Oct 2022 18:00:00 GMT", "version": "v1" }, { "created": "Sun, 30 Apr 2023 09:11:03 GMT", "version": "v2" } ]
2023-05-02
[ [ "Geller", "Michael", "" ], [ "Heller-Algazi", "Zamir", "" ] ]
We consider a dark sector scenario with two dark matter species with opposite dark $U(1)$ charges and an asymmetric population comprising some fraction of the dark matter abundance. A new mechanism for boosting dark matter is introduced, arising from the large mass hierarchy between the two particles. In the galaxy, the two species thermalize efficiently through dark Rutherford scattering greatly boosting the lighter dark matter particle, far above the virial and escape velocities in the galaxy, while the dark charge prevents it from escaping. We study the consequences of this scenario for direct-detection experiments, assuming a kinetic mixing between the dark photon and the photon. If the charged dark sector makes up 5% of the total DM mass in our galaxy and the mass ratio is between $10^3-10^4$, we find that current and future experiments may probe the boosted light dark matter for masses down to 100 keV, in a hitherto unexplored parameter range.
1601.06328
Stanley J. Brodsky
Stanley J. Brodsky
Light-Front Holography, Color Confinement, and Supersymmetric Features of QCD
Invited Talk, presented at Light-Cone 2015, Theory and Experiment for Hadrons on the Light-Front, September 21-25, 2015, INFN, Frascati, Italy. arXiv admin note: substantial text overlap with arXiv:1512.05100, arXiv:1511.04142
null
10.1007/s00601-016-1070-8
SLAC-PUB-16453
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Light-Front Quantization provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the hadronic light-front wavefunctions. One obtains new insights into the hadronic spectrum, light-front wavefunctions, and the functional form of the QCD running coupling in the nonperturbative domain using light-front holography -- the duality between the front form and AdS$_5$, the space of isometries of the conformal group. In addition, superconformal algebra leads to remarkable supersymmetric relations between mesons and baryons of the same parity. The mass scale $\kappa$ underlying confinement and hadron masses can be connected to the parameter $\Lambda_{\overline {MS}}$ in the QCD running coupling by matching the nonperturbative dynamics, as described by the effective conformal theory mapped to the light-front and its embedding in AdS space, to the perturbative QCD regime. The result is an effective coupling defined at all momenta. This matching of the high and low momentum transfer regimes determines a scale $Q_0$ which sets the interface between perturbative and nonperturbative hadron dynamics. The use of $Q_0$ to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with the principle of maximal conformality (PMC) for setting the renormalization scales, can greatly improve the precision of perturbative QCD predictions for collider phenomenology. The absence of vacuum excitations of the front-form vacuum has important consequences for the cosmological constant. I also discuss evidence that the antishadowing of nuclear structure functions is flavor dependent, and why shadowing and antishadowing phenomena may be incompatible with sum rules for nuclear parton distribution functions.
[ { "created": "Sat, 23 Jan 2016 23:43:35 GMT", "version": "v1" } ]
2016-04-20
[ [ "Brodsky", "Stanley J.", "" ] ]
Light-Front Quantization provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the hadronic light-front wavefunctions. One obtains new insights into the hadronic spectrum, light-front wavefunctions, and the functional form of the QCD running coupling in the nonperturbative domain using light-front holography -- the duality between the front form and AdS$_5$, the space of isometries of the conformal group. In addition, superconformal algebra leads to remarkable supersymmetric relations between mesons and baryons of the same parity. The mass scale $\kappa$ underlying confinement and hadron masses can be connected to the parameter $\Lambda_{\overline {MS}}$ in the QCD running coupling by matching the nonperturbative dynamics, as described by the effective conformal theory mapped to the light-front and its embedding in AdS space, to the perturbative QCD regime. The result is an effective coupling defined at all momenta. This matching of the high and low momentum transfer regimes determines a scale $Q_0$ which sets the interface between perturbative and nonperturbative hadron dynamics. The use of $Q_0$ to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with the principle of maximal conformality (PMC) for setting the renormalization scales, can greatly improve the precision of perturbative QCD predictions for collider phenomenology. The absence of vacuum excitations of the front-form vacuum has important consequences for the cosmological constant. I also discuss evidence that the antishadowing of nuclear structure functions is flavor dependent, and why shadowing and antishadowing phenomena may be incompatible with sum rules for nuclear parton distribution functions.
hep-ph/0210368
Gudrid Moortgat-Pick
G. Moortgat-Pick, S. Rolli, A.F. Zarnecki
Physics at large p_T^2 and Q^2: Summary
27 pages,35 figures;to appear in the Proceedings of the X. International Workshop on Deep Inelastic Scattering (DIS2002) Cracow, Poland, 30 April--4 May, 2002
Acta Phys.Polon.B33:3955-3981,2002
null
DESY 02-111, TUFTS CONF-02/21-1-E
hep-ph hep-ex
null
We summarize the results presented in the `Physics at large p_T^2 and Q^2' working group at the DIS'2002 Workshop. Higgs searches, precision measurements as well as searches for physics beyond the Standard Model at current and future experiments are reviewed.
[ { "created": "Sun, 27 Oct 2002 20:29:14 GMT", "version": "v1" } ]
2011-03-23
[ [ "Moortgat-Pick", "G.", "" ], [ "Rolli", "S.", "" ], [ "Zarnecki", "A. F.", "" ] ]
We summarize the results presented in the `Physics at large p_T^2 and Q^2' working group at the DIS'2002 Workshop. Higgs searches, precision measurements as well as searches for physics beyond the Standard Model at current and future experiments are reviewed.
1608.02103
Mohammad Athar SAJJAD
F. Akbar, M. Rafi Alam, M. Sajjad Athar and S. K. Singh
Quasielastic production of polarized hyperons in antineutrino--nucleon reactions
23 Pages, 23 Figures
Phys. Rev. D 94, 114031 (2016)
10.1103/PhysRevD.94.114031
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have studied the differential cross section as well as the longitudinal and perpendicular components of polarization of final hyperon($\Lambda$,$\Sigma$) produced in the antineutrino induced quasielastic charged current reactions on nucleon and nuclear targets. The nucleon-hyperon transition form factors are determined from the experimental data on quasielastic $(\Delta S =0)$ charged current (anti)neutrino--nucleon scattering and the semileptonic decay of neutron and hyperons assuming G--invariance, T--invariance and SU(3) symmetry. The vector transition form factors are obtained in terms of nucleon electromagnetic form factors for which various parameterizations available in literature have been used. A dipole parameterization for the axial vector form factor and the pseudoscalar transition form factor derived in terms of axial vector form factor assuming PCAC and GT relation extended to strangeness sector have been used in numerical evaluations. The flux averaged cross section and polarization observables corresponding to CERN Gargamelle experiment have been calculated for quasielastic hyperon production and found to be in reasonable agreement with the experimental observations. The numerical results for the flux averaged differential cross section$\frac{d\sigma}{dQ^2}$ and longitudinal(perpendicular) polarization $P_L(Q^2)(P_P(Q^2))$ relevant for the antineutrino fluxes of MINER$\nu$A, MicroBooNE, and T2K experiments have been presented. This will be useful in interpreting future experimental results on production cross sections and polarization observables from the experiments on the quasielastic production of hyperons induced by antineutrinos and explore the possibility of determining the axial vector and pseudoscalar form factors in the strangeness sector.
[ { "created": "Sat, 6 Aug 2016 12:48:22 GMT", "version": "v1" }, { "created": "Thu, 22 Dec 2016 05:18:19 GMT", "version": "v2" } ]
2017-01-04
[ [ "Akbar", "F.", "" ], [ "Alam", "M. Rafi", "" ], [ "Athar", "M. Sajjad", "" ], [ "Singh", "S. K.", "" ] ]
We have studied the differential cross section as well as the longitudinal and perpendicular components of polarization of final hyperon($\Lambda$,$\Sigma$) produced in the antineutrino induced quasielastic charged current reactions on nucleon and nuclear targets. The nucleon-hyperon transition form factors are determined from the experimental data on quasielastic $(\Delta S =0)$ charged current (anti)neutrino--nucleon scattering and the semileptonic decay of neutron and hyperons assuming G--invariance, T--invariance and SU(3) symmetry. The vector transition form factors are obtained in terms of nucleon electromagnetic form factors for which various parameterizations available in literature have been used. A dipole parameterization for the axial vector form factor and the pseudoscalar transition form factor derived in terms of axial vector form factor assuming PCAC and GT relation extended to strangeness sector have been used in numerical evaluations. The flux averaged cross section and polarization observables corresponding to CERN Gargamelle experiment have been calculated for quasielastic hyperon production and found to be in reasonable agreement with the experimental observations. The numerical results for the flux averaged differential cross section$\frac{d\sigma}{dQ^2}$ and longitudinal(perpendicular) polarization $P_L(Q^2)(P_P(Q^2))$ relevant for the antineutrino fluxes of MINER$\nu$A, MicroBooNE, and T2K experiments have been presented. This will be useful in interpreting future experimental results on production cross sections and polarization observables from the experiments on the quasielastic production of hyperons induced by antineutrinos and explore the possibility of determining the axial vector and pseudoscalar form factors in the strangeness sector.
hep-ph/0606287
Kazuhide Ichikawa
Kazuhide Ichikawa, Tomo Takahashi, Masahide Yamaguchi
Implications of cosmic strings with time-varying tension on CMB and large scale structure
17 pages, 7 figures
Phys.Rev.D74:063526,2006
10.1103/PhysRevD.74.063526
null
hep-ph astro-ph
null
We investigate cosmological evolution and implications of cosmic strings with time-dependent tension. We derive basic equations of time development of the correlation length and the velocity of such strings, based on the one scale model. Then, we find that, in the case where the tension depends on some power of the cosmic time, cosmic strings with time-dependent tension goes into the scaling solution if the power is lower than a critical value. We also discuss cosmic microwave background anisotropy and matter power spectra produced by these strings. The constraints on their tensions from the Wilkinson microwave anisotropy probe (WMAP) three year data and Sloan digital sky survey (SDSS) data are also given.
[ { "created": "Wed, 28 Jun 2006 15:20:08 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ichikawa", "Kazuhide", "" ], [ "Takahashi", "Tomo", "" ], [ "Yamaguchi", "Masahide", "" ] ]
We investigate cosmological evolution and implications of cosmic strings with time-dependent tension. We derive basic equations of time development of the correlation length and the velocity of such strings, based on the one scale model. Then, we find that, in the case where the tension depends on some power of the cosmic time, cosmic strings with time-dependent tension goes into the scaling solution if the power is lower than a critical value. We also discuss cosmic microwave background anisotropy and matter power spectra produced by these strings. The constraints on their tensions from the Wilkinson microwave anisotropy probe (WMAP) three year data and Sloan digital sky survey (SDSS) data are also given.
hep-ph/0101154
Ahmed Ali
A. Ali (DESY)
Photonic and Leptonic Rare B Decays
24 pages, 5 figures (requires epsf); Invited Talk, Beauty 2000, Sea of Galilee, Israel, September 13 - 19, 2000
Nucl.Instrum.Meth.A462:11-22,2001
10.1016/S0168-9002(01)00065-1
DESY 00-186
hep-ph
null
Some selected topics involving photonic and leptonic rare B decays are reviewed. The interest in their measurement for the CKM phenomenology is underlined. They are also potentially interesting in searching for physics beyond the standard model. This is illustrated on the examples of the decays $B \to (K,K^*) \ell^+ \ell^-$ and $B \to (\rho, \omega) \gamma$ by contrasting their anticipated phenomenological profiles in the standard model and some variants of supersymmetric models.
[ { "created": "Mon, 15 Jan 2001 12:02:38 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ali", "A.", "", "DESY" ] ]
Some selected topics involving photonic and leptonic rare B decays are reviewed. The interest in their measurement for the CKM phenomenology is underlined. They are also potentially interesting in searching for physics beyond the standard model. This is illustrated on the examples of the decays $B \to (K,K^*) \ell^+ \ell^-$ and $B \to (\rho, \omega) \gamma$ by contrasting their anticipated phenomenological profiles in the standard model and some variants of supersymmetric models.
hep-ph/0005235
Jim Cline
James M. Cline, Hassan Firouzjahi
Brane-World Cosmology of Modulus Stabilization with a Bulk Scalar Field
12 pages, 6 figures
Phys.Rev. D64 (2001) 023505
10.1103/PhysRevD.64.023505
McGill-00-14
hep-ph hep-th
null
We point out that the potential of Goldberger and Wise for stabilizing the distance between two 3-branes, separated from each other along an extra dimension with a warp factor, has a metastable minimum when the branes are infinitely separated. The classical evolution of the radion (brane separation) will place it in this false minimum for generic initial conditions. In particular, inflation could do this if the expansion rate is sufficiently large. We present a simplified version of the Goldberger-Wise mechanism in which the radion potential can be computed exactly, and we calculate the rate of thermal transitions to the true minimum, showing that model parameters can be chosen to ensure that the universe reaches the desired final state. Finiteness of bulk scalar field brane potentials can have an important impact on the nucleation rate, and it can also significantly increase the predicted mass of the radion.
[ { "created": "Tue, 23 May 2000 22:10:27 GMT", "version": "v1" } ]
2009-10-31
[ [ "Cline", "James M.", "" ], [ "Firouzjahi", "Hassan", "" ] ]
We point out that the potential of Goldberger and Wise for stabilizing the distance between two 3-branes, separated from each other along an extra dimension with a warp factor, has a metastable minimum when the branes are infinitely separated. The classical evolution of the radion (brane separation) will place it in this false minimum for generic initial conditions. In particular, inflation could do this if the expansion rate is sufficiently large. We present a simplified version of the Goldberger-Wise mechanism in which the radion potential can be computed exactly, and we calculate the rate of thermal transitions to the true minimum, showing that model parameters can be chosen to ensure that the universe reaches the desired final state. Finiteness of bulk scalar field brane potentials can have an important impact on the nucleation rate, and it can also significantly increase the predicted mass of the radion.
0704.0167
Jan O. Eeg
Jan O. Eeg
Low Energy Aspects of Heavy Meson Decays
10 pages, 10 figures. Presented at the final Euridice meeting in Kazimierz, Poland 24-27th of august 2006
ActaPhys.Polon.B38:2869-2878,2007
null
null
hep-ph
null
I discuss low energy aspects of heavy meson decays, where there is at least one heavy meson in the final state. Examples are $B -\bar{B}$ mixing, $B \to D \bar{D}$, $B \to D \eta'$, and $B \to D \gamma$. %and $B \to D W $ (Isgur-Wise function). The analysis is performed in the heavy quark limit within heavy-light chiral perturbation theory. Coefficients of $1/N_c$ suppressed chiral Lagrangian terms (beyond factorization) have been estimated by means of a heavy-light chiral quark model.
[ { "created": "Mon, 2 Apr 2007 11:03:26 GMT", "version": "v1" } ]
2008-11-26
[ [ "Eeg", "Jan O.", "" ] ]
I discuss low energy aspects of heavy meson decays, where there is at least one heavy meson in the final state. Examples are $B -\bar{B}$ mixing, $B \to D \bar{D}$, $B \to D \eta'$, and $B \to D \gamma$. %and $B \to D W $ (Isgur-Wise function). The analysis is performed in the heavy quark limit within heavy-light chiral perturbation theory. Coefficients of $1/N_c$ suppressed chiral Lagrangian terms (beyond factorization) have been estimated by means of a heavy-light chiral quark model.
1807.04306
Hoda Hesari
Hoda Hesari
Probing Higgs boson couplings in $t\bar{t}b\bar{b}$ production at the LHC
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we investigate the effects of dimension six operators in the framework of the standard model (SM) effective field theory on using $t\bar{t}b\bar{b}$ channel at the LHC with the center-of-mass energy of 13 TeV. In this analysis, we only assume leptonic top-quarks. Once the events were simulated, the CMS-measured cross-section was used to constrain the corresponding effective Wilson coefficients at $95\%$ confidence level. Considering the SM effective Lagrangian, the $t\bar{t}b\bar{b}$ events in proton-proton collision were very sensitive to the effective Wilson coefficients $ \bar{C}_{g},\tilde{C_{g}},\bar{C}_{uG},\bar{C}_{uW}$. We show that using $t\bar{t}b\bar{b}$ events, we can provide stronger constraints on these Wilson coefficients than the current ones obtained from other channels.
[ { "created": "Wed, 11 Jul 2018 18:13:12 GMT", "version": "v1" } ]
2018-07-13
[ [ "Hesari", "Hoda", "" ] ]
In this paper, we investigate the effects of dimension six operators in the framework of the standard model (SM) effective field theory on using $t\bar{t}b\bar{b}$ channel at the LHC with the center-of-mass energy of 13 TeV. In this analysis, we only assume leptonic top-quarks. Once the events were simulated, the CMS-measured cross-section was used to constrain the corresponding effective Wilson coefficients at $95\%$ confidence level. Considering the SM effective Lagrangian, the $t\bar{t}b\bar{b}$ events in proton-proton collision were very sensitive to the effective Wilson coefficients $ \bar{C}_{g},\tilde{C_{g}},\bar{C}_{uG},\bar{C}_{uW}$. We show that using $t\bar{t}b\bar{b}$ events, we can provide stronger constraints on these Wilson coefficients than the current ones obtained from other channels.
hep-ph/0410345
Takashi Ikeda
T. Ikeda, L. McLerran
Impact Parameter Dependence in the Balitsky-Kovchegov Equation
15 pages, 7 figures
Nucl.Phys. A756 (2005) 385-398
10.1016/j.nuclphysa.2005.03.119
null
hep-ph
null
We study the impact parameter dependence of solutions to the Balitsky-Kovchegov (BK) equation. We argue that if the kernel of the BK integral equation is regulated to cutoff infrared singularities, then it can be approximated by an equation without diffusion in impact parameter. For some purposes, when momentum scales large compared to $\Lambda_{QCD}$ are probed, the kernel may be approximated as massless. In particular, we find that the Froissart bound limit is saturated for physical initial conditions and seem to be independent of the cutoff so long as the cutoff is sufficiently large compared to the momentum scale associated with the large distance falloff of the impact parameter distribution.
[ { "created": "Tue, 26 Oct 2004 15:31:10 GMT", "version": "v1" } ]
2009-11-10
[ [ "Ikeda", "T.", "" ], [ "McLerran", "L.", "" ] ]
We study the impact parameter dependence of solutions to the Balitsky-Kovchegov (BK) equation. We argue that if the kernel of the BK integral equation is regulated to cutoff infrared singularities, then it can be approximated by an equation without diffusion in impact parameter. For some purposes, when momentum scales large compared to $\Lambda_{QCD}$ are probed, the kernel may be approximated as massless. In particular, we find that the Froissart bound limit is saturated for physical initial conditions and seem to be independent of the cutoff so long as the cutoff is sufficiently large compared to the momentum scale associated with the large distance falloff of the impact parameter distribution.
1507.06454
Gennady Kozlov
G.A. Kozlov
Dark photons in the decay of Higgs-like boson
14 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the dark matter particle, the dark photon (DP), in the decay of the Higgs-like boson. The nature of dark matter is maintained through the hidden sector including the effects of breaking of the scale invariance. The model is based on the additional $U^{\prime}(1)$ gauge group associated with light DP. The interaction between DP and quarks is mediated by the derivative of the scalar - the dilaton. The latter appears in the conformal sector which triggers the electroweak symmetry breaking. Upper limits are set on the DP mass, the mixing strength between the standard photon and DP. The model does allow to estimate the DP mass with the value of 4.5 MeV. The maximal value of the scale invariance breaking constant is also reported.
[ { "created": "Thu, 23 Jul 2015 11:42:05 GMT", "version": "v1" } ]
2015-07-24
[ [ "Kozlov", "G. A.", "" ] ]
We study the dark matter particle, the dark photon (DP), in the decay of the Higgs-like boson. The nature of dark matter is maintained through the hidden sector including the effects of breaking of the scale invariance. The model is based on the additional $U^{\prime}(1)$ gauge group associated with light DP. The interaction between DP and quarks is mediated by the derivative of the scalar - the dilaton. The latter appears in the conformal sector which triggers the electroweak symmetry breaking. Upper limits are set on the DP mass, the mixing strength between the standard photon and DP. The model does allow to estimate the DP mass with the value of 4.5 MeV. The maximal value of the scale invariance breaking constant is also reported.
1901.05325
Ambalika Biswas
Ambalika Biswas
Is Higgsium a possibility in 2HDMs?
23 pages, 1 figure
null
10.1016/j.nuclphysb.2019.114885
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility of a Higgs-Higgs bound state in the two Higgs doublet model. Specifically we look for the effect of dimension six operators, generated by new physics at a scale of a few TeV, on the self-couplings of the heavy CP even scalar field in the model. Following the pioneering work of Grinstein and Trott, we construct an effective field theory formalism to examine the physics of the Higgs sector. The magnitudes of the attractive and repulsive coupling strengths are compared to estimate the possibility of the formation of the $H-H$ bound state. Another way to check if a bound state is formed or not is from the formation and decay times of the bound state. The possibilities in various types of two Higgs doublet models have been discussed elaborately in the paper.
[ { "created": "Tue, 15 Jan 2019 18:53:07 GMT", "version": "v1" }, { "created": "Thu, 17 Jan 2019 18:07:57 GMT", "version": "v2" } ]
2020-04-22
[ [ "Biswas", "Ambalika", "" ] ]
We investigate the possibility of a Higgs-Higgs bound state in the two Higgs doublet model. Specifically we look for the effect of dimension six operators, generated by new physics at a scale of a few TeV, on the self-couplings of the heavy CP even scalar field in the model. Following the pioneering work of Grinstein and Trott, we construct an effective field theory formalism to examine the physics of the Higgs sector. The magnitudes of the attractive and repulsive coupling strengths are compared to estimate the possibility of the formation of the $H-H$ bound state. Another way to check if a bound state is formed or not is from the formation and decay times of the bound state. The possibilities in various types of two Higgs doublet models have been discussed elaborately in the paper.
2305.14025
Sebastian Sapeta
Tomoki Goda, Krzysztof Kutak, Sebastian Sapeta
Effects of gluon kinematics and the Sudakov form factor on the dipole amplitude
19 pages, 8 figures; v2: references added
null
null
IFJPAN-IV-2023-2
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate effects of exact gluon kinematics on the parameters of the Golec-Biernat-W\"usthoff, and Bartels-Golec-Biernat-Kowalski saturation models. The resulting fits show some differences, particularly, in the normalization of the dipole cross section $\sigma_0$. The refitted models are used for the dijet production process in DIS to investigate effects of the Sudakov form factor at Electron Ion Collider energies.
[ { "created": "Tue, 23 May 2023 12:58:52 GMT", "version": "v1" }, { "created": "Mon, 29 May 2023 14:51:40 GMT", "version": "v2" } ]
2023-05-30
[ [ "Goda", "Tomoki", "" ], [ "Kutak", "Krzysztof", "" ], [ "Sapeta", "Sebastian", "" ] ]
We investigate effects of exact gluon kinematics on the parameters of the Golec-Biernat-W\"usthoff, and Bartels-Golec-Biernat-Kowalski saturation models. The resulting fits show some differences, particularly, in the normalization of the dipole cross section $\sigma_0$. The refitted models are used for the dijet production process in DIS to investigate effects of the Sudakov form factor at Electron Ion Collider energies.
hep-ph/9404362
Arnd Leike
D. Choudhury, F. Cuypers, A. Leike
Model-Independent $Z'$ Limits from Electron-Electron Collisions
7 pages, LaTeX, 4 Figures, uuencoded Postscriptfile, MPI-Ph/94-23, LMU-04/94
Phys.Lett. B333 (1994) 531-535
10.1016/0370-2693(94)90179-1
null
hep-ph
null
Model independent constraints on the mass of an extra neutral gauge boson and its couplings to charged leptons are given for the $e^-e^-$ option of a future linear collider. Analytic exclusion limits are derived in the Born approximation. The results are compared with those of the $e^+e^-$ mode. The influence of radiative corrections is discussed.
[ { "created": "Mon, 2 May 1994 07:08:33 GMT", "version": "v1" } ]
2009-10-28
[ [ "Choudhury", "D.", "" ], [ "Cuypers", "F.", "" ], [ "Leike", "A.", "" ] ]
Model independent constraints on the mass of an extra neutral gauge boson and its couplings to charged leptons are given for the $e^-e^-$ option of a future linear collider. Analytic exclusion limits are derived in the Born approximation. The results are compared with those of the $e^+e^-$ mode. The influence of radiative corrections is discussed.
hep-ph/9712268
Sarira Sahu
Sarira Sahu
Cosmic Rays Propagation in Bose Condensed Dark Matter
5 pages, revtex
Mod.Phys.Lett. A14 (1999) 1287-1295
10.1142/S0217732399001371
null
hep-ph
null
We have calculated the dispersion relation for the high energy cosmic rays (protons, electrons and neutrinos) propagating in the Bose gas as well as Bose condensate medium of the pseudo-scalar particles. For cosmic rays propagating in the Bose gas, the mass of the particle will decrease and this is proportional to the boson density in the medium. If the propagating fermion is massless then it will develop an imaginary mass and thus will be absorbed in the medium. But if the condition $m^2/m_{\phi}p_0\simeq 1$ is satisfied, then the cosmic rays will propagate freely without loosing energy in the Bose condensate medium.
[ { "created": "Thu, 4 Dec 1997 16:52:54 GMT", "version": "v1" } ]
2009-10-30
[ [ "Sahu", "Sarira", "" ] ]
We have calculated the dispersion relation for the high energy cosmic rays (protons, electrons and neutrinos) propagating in the Bose gas as well as Bose condensate medium of the pseudo-scalar particles. For cosmic rays propagating in the Bose gas, the mass of the particle will decrease and this is proportional to the boson density in the medium. If the propagating fermion is massless then it will develop an imaginary mass and thus will be absorbed in the medium. But if the condition $m^2/m_{\phi}p_0\simeq 1$ is satisfied, then the cosmic rays will propagate freely without loosing energy in the Bose condensate medium.
hep-ph/0008154
Michael Kraemer
Robert Blair (ANL), G\"unter Grindhammer (MPI M\"unchen), Michael Klasen (Hamburg U.), Michael Kr\"amer (Edinburgh U.)
Tests of QCD: Summary of DIS 2000
16 pages, LaTeX, including 8 PostScript figures. Talk given at the 8th International Workshop on Deep-Inelastic Scattering (DIS2000), 25th-30th April 2000, Liverpool, England, to appear in the proceedings
null
null
null
hep-ph
null
This summary of the working group 2 of DIS 2000 encompasses experimental and theoretical results of jet physics, open and bound state heavy flavour production, prompt photon production, next-to-leading order QCD calculations and beyond, instantons, fragmentation, event shapes, and power corrections, primarily from deep-inelastic scattering and photoproduction at HERA, but also from the LEP and Tevatron colliders.
[ { "created": "Tue, 15 Aug 2000 16:46:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Blair", "Robert", "", "ANL" ], [ "Grindhammer", "Günter", "", "MPI München" ], [ "Klasen", "Michael", "", "Hamburg U." ], [ "Krämer", "Michael", "", "Edinburgh U." ] ]
This summary of the working group 2 of DIS 2000 encompasses experimental and theoretical results of jet physics, open and bound state heavy flavour production, prompt photon production, next-to-leading order QCD calculations and beyond, instantons, fragmentation, event shapes, and power corrections, primarily from deep-inelastic scattering and photoproduction at HERA, but also from the LEP and Tevatron colliders.
0707.0276
Zhong-Bo Kang
Zhong-Bo Kang and Jian-Wei Qiu
Transverse momentum broadening of vector bosons in heavy ion collisions at the LHC
2 pages, 2 figures. Contributed to Workshop on Heavy Ion Collisions at the LHC: Last Call for Predictions, Geneva, Switzerland, 14 May - 8 Jun 2007
null
null
null
hep-ph
null
We calculate in perturbative QCD the transverse momentum broadening of vector bosons in heavy ion collisions at the Large Hadron Collider (LHC). We predict transverse momentum broadening of $W/Z$ bosons constructed from their leptonic decay channels, which should be a clean probe of initial-state medium effect. We also predict the upper limit of transverse momentum broadening of J/$\psi$ and $\Upsilon$ production as a function of N$_{\rm part}$ at the LHC energy.
[ { "created": "Mon, 2 Jul 2007 17:24:08 GMT", "version": "v1" } ]
2007-07-03
[ [ "Kang", "Zhong-Bo", "" ], [ "Qiu", "Jian-Wei", "" ] ]
We calculate in perturbative QCD the transverse momentum broadening of vector bosons in heavy ion collisions at the Large Hadron Collider (LHC). We predict transverse momentum broadening of $W/Z$ bosons constructed from their leptonic decay channels, which should be a clean probe of initial-state medium effect. We also predict the upper limit of transverse momentum broadening of J/$\psi$ and $\Upsilon$ production as a function of N$_{\rm part}$ at the LHC energy.
0904.1293
Wolfgang Ehrenfeld
Wolfgang Ehrenfeld, Ayres Freitas, Ananda Landwehr, Daniel Wyler
Distinguishing spins in decay chains with photons at the Large Hadron Collider
26 pages, 7 postscript figures, published version
JHEP 0907:056,2009
10.1088/1126-6708/2009/07/056
DESY 09-048, MPP-2009-23, ZU-TH 01/09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several models for physics beyond the Standard Model predict new particles with a decay signature including hard photons and missing energy. Two well-motivated examples are supersymmetry with gauge-mediated breaking (GMSB) and the standard model with two universal extra dimensions. Both models lead to decay chains with similar collider signatures, including hard photon emission. The main discriminating feature are the spins of the new particles. In this paper we discuss how information about the spins of the particles can be extracted from lepton-photon or quark-photon invariant mass distributions at the Large Hadron Collider. The characteristic shapes of the distributions are derived analytically and then studied in a realistic Monte-Carlo simulation. We find that for a typical GMSB mass spectrum with particle masses below 1 TeV, already 10 fb$^{-1}$ integrated luminosity at 14 TeV center-of-mass energy are sufficient to discriminate the two models with high significance.
[ { "created": "Wed, 8 Apr 2009 10:02:14 GMT", "version": "v1" }, { "created": "Tue, 4 Aug 2009 08:42:16 GMT", "version": "v2" } ]
2009-08-04
[ [ "Ehrenfeld", "Wolfgang", "" ], [ "Freitas", "Ayres", "" ], [ "Landwehr", "Ananda", "" ], [ "Wyler", "Daniel", "" ] ]
Several models for physics beyond the Standard Model predict new particles with a decay signature including hard photons and missing energy. Two well-motivated examples are supersymmetry with gauge-mediated breaking (GMSB) and the standard model with two universal extra dimensions. Both models lead to decay chains with similar collider signatures, including hard photon emission. The main discriminating feature are the spins of the new particles. In this paper we discuss how information about the spins of the particles can be extracted from lepton-photon or quark-photon invariant mass distributions at the Large Hadron Collider. The characteristic shapes of the distributions are derived analytically and then studied in a realistic Monte-Carlo simulation. We find that for a typical GMSB mass spectrum with particle masses below 1 TeV, already 10 fb$^{-1}$ integrated luminosity at 14 TeV center-of-mass energy are sufficient to discriminate the two models with high significance.
2407.14182
Kapil Saraswat
Kapil Saraswat, Deependra Singh Rawat, Akash Pandey, Venktesh Singh, H. C. Chandola
Phenomenological study of the charged particles production in pPb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV
arXiv admin note: substantial text overlap with arXiv:2405.12231
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We have studied transverse momentum ($p_{\rm{T}}$) spectra of charged hadrons in various pseudo-rapidity ranges for p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV. The medium effects such as collective flow and energy loss resulting from heavy-ion collisions have also been investigated using modified Tsallis distribution function over a wide range of $p_{\rm{T}}$ that indicates the transverse collective flow at low and intermediate $p_{\rm{T}}$ range and in-medium energy loss in high $p_{\rm{T}}$ range.
[ { "created": "Fri, 19 Jul 2024 10:22:50 GMT", "version": "v1" } ]
2024-07-22
[ [ "Saraswat", "Kapil", "" ], [ "Rawat", "Deependra Singh", "" ], [ "Pandey", "Akash", "" ], [ "Singh", "Venktesh", "" ], [ "Chandola", "H. C.", "" ] ]
We have studied transverse momentum ($p_{\rm{T}}$) spectra of charged hadrons in various pseudo-rapidity ranges for p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV. The medium effects such as collective flow and energy loss resulting from heavy-ion collisions have also been investigated using modified Tsallis distribution function over a wide range of $p_{\rm{T}}$ that indicates the transverse collective flow at low and intermediate $p_{\rm{T}}$ range and in-medium energy loss in high $p_{\rm{T}}$ range.
1509.02934
Andrey Katz
Andrey Katz, Maxim Perelstein, Michael J. Ramsey-Musolf, Peter Winslow
Stop-Catalyzed Baryogenesis Beyond the MSSM
9 pages, 3 figures. v2: Minor changes. Added appendix with the details of the higgs couplings fit. References added
Phys. Rev. D 92, 095019 (2015)
10.1103/PhysRevD.92.095019
CERN-PH-TH-2015-217, ACFI-T15-15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-minimal supersymmetric models that predict a tree-level Higgs mass above the Minimal Supersymmetric Standard Model (MSSM) bound are well motivated by naturalness considerations. Indirect constraints on the stop sector parameters of such models are significantly relaxed compared to the MSSM; in particular, both stops can have weak-scale masses. We revisit the stop-catalyzed electroweak baryogenesis (EWB) scenario in this context. We find that the LHC measurements of the Higgs boson production and decay rates already rule out the possibility of stop-catalyzed EWB. We also introduce a gauge-invariant analysis framework that may generalize to other scenarios in which interactions outside the gauge sector drive the electroweak phase transition.
[ { "created": "Wed, 9 Sep 2015 20:17:09 GMT", "version": "v1" }, { "created": "Thu, 28 Jan 2016 16:57:59 GMT", "version": "v2" } ]
2016-01-29
[ [ "Katz", "Andrey", "" ], [ "Perelstein", "Maxim", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Winslow", "Peter", "" ] ]
Non-minimal supersymmetric models that predict a tree-level Higgs mass above the Minimal Supersymmetric Standard Model (MSSM) bound are well motivated by naturalness considerations. Indirect constraints on the stop sector parameters of such models are significantly relaxed compared to the MSSM; in particular, both stops can have weak-scale masses. We revisit the stop-catalyzed electroweak baryogenesis (EWB) scenario in this context. We find that the LHC measurements of the Higgs boson production and decay rates already rule out the possibility of stop-catalyzed EWB. We also introduce a gauge-invariant analysis framework that may generalize to other scenarios in which interactions outside the gauge sector drive the electroweak phase transition.
1109.4958
Matthew Dolan
Matthew J. Dolan, Joseph Marsano and Sakura Schafer-Nameki
Unification and Phenomenology of F-Theory GUTs with U(1)_PQ
46 pages, 15 figures
null
10.1007/JHEP12(2011)032
IPPP-11-57, DCPT-11-114, EFI-11-27, KCL-MTH-11-17
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We undertake a phenomenological study of SU(5) F-theory GUT models with an additional U(1)_{PQ} symmetry. In such models, breaking SU(5) with hypercharge flux leads to the presence of non-GUT multiplets in the spectrum. We study the effect these have on the unification of gauge couplings, including two-loop running as well as low- and high-scale threshold corrections. We use the requirement of unification to constrain the size of thresholds from KK modes of SU(5) gauge and matter fields. Assuming the non-GUT multiplets play the role of messengers of gauge mediation leads to controlled non-universalities in the sparticle spectrum while maintaining grand unification, and we study the LHC phenomenology of this scenario. We find that the MSSM spectrum may become compressed or stretched out {by up to a factor of three} depending on the distribution of hypercharge flux. We present a set of benchmark points whose production cross-sections and decays we investigate, and argue that precision kinematic edge measurements will allow the LHC to distinguish between our model and mGMSB.
[ { "created": "Thu, 22 Sep 2011 21:43:40 GMT", "version": "v1" } ]
2015-05-30
[ [ "Dolan", "Matthew J.", "" ], [ "Marsano", "Joseph", "" ], [ "Schafer-Nameki", "Sakura", "" ] ]
We undertake a phenomenological study of SU(5) F-theory GUT models with an additional U(1)_{PQ} symmetry. In such models, breaking SU(5) with hypercharge flux leads to the presence of non-GUT multiplets in the spectrum. We study the effect these have on the unification of gauge couplings, including two-loop running as well as low- and high-scale threshold corrections. We use the requirement of unification to constrain the size of thresholds from KK modes of SU(5) gauge and matter fields. Assuming the non-GUT multiplets play the role of messengers of gauge mediation leads to controlled non-universalities in the sparticle spectrum while maintaining grand unification, and we study the LHC phenomenology of this scenario. We find that the MSSM spectrum may become compressed or stretched out {by up to a factor of three} depending on the distribution of hypercharge flux. We present a set of benchmark points whose production cross-sections and decays we investigate, and argue that precision kinematic edge measurements will allow the LHC to distinguish between our model and mGMSB.
hep-ph/0103116
Chih-Lung Chou
Chih-Lung Chou and Chung-Hsien Chou
Tau Polarizations in the Three-body Slepton Decays with Stau as the NLSP
13 pages, 5 figures, RevTex
Phys.Rev. D64 (2001) 075008
10.1103/PhysRevD.64.075008
null
hep-ph
null
In the gauge-mediated supersymmetry breaking models with scalar tau as the next-to-lightest supersymmetric particle, a scalar lepton may decay dominantly into its superpartner, tau lepton, and the lightest scalar tau particle. We give detailed formulas for the three-body decay amplitudes and the polarization asymmetry of the outgoing tau lepton . We find that the tau polarizations are sensitive to the model parameters such as the stau mixing angle, the neutralino to slepton mass ratio and the neutralino mixing effect.
[ { "created": "Mon, 12 Mar 2001 08:58:41 GMT", "version": "v1" }, { "created": "Mon, 23 Jul 2001 10:12:24 GMT", "version": "v2" } ]
2009-11-07
[ [ "Chou", "Chih-Lung", "" ], [ "Chou", "Chung-Hsien", "" ] ]
In the gauge-mediated supersymmetry breaking models with scalar tau as the next-to-lightest supersymmetric particle, a scalar lepton may decay dominantly into its superpartner, tau lepton, and the lightest scalar tau particle. We give detailed formulas for the three-body decay amplitudes and the polarization asymmetry of the outgoing tau lepton . We find that the tau polarizations are sensitive to the model parameters such as the stau mixing angle, the neutralino to slepton mass ratio and the neutralino mixing effect.
0904.0969
John McDonald
John McDonald
Enhanced Dark Matter Annihilation Rate for Positron and Electron Excesses from Q-ball Decay
4 pages, version to be published in Physical Review Letters
Phys.Rev.Lett.103:151301,2009
10.1103/PhysRevLett.103.151301
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that Q-ball decay in Affleck-Dine baryogenesis models can account for dark matter when the annihilation cross-section is sufficiently enhanced to explain the positron and electron excesses observed by PAMELA, ATIC and PPB-BETS. For Affleck-Dine baryogenesis along a d = 6 flat direction, the reheating temperature is approximately 30 GeV and the Q-ball decay temperature is in the range 10-100 MeV. The LSPs produced by Q-ball decay annihilate down to the observed dark matter density if the cross-section is enhanced by a factor ~ 10^3 relative to the thermal relic cross-section.
[ { "created": "Mon, 6 Apr 2009 19:37:27 GMT", "version": "v1" }, { "created": "Mon, 6 Apr 2009 22:32:48 GMT", "version": "v2" }, { "created": "Fri, 24 Apr 2009 16:07:02 GMT", "version": "v3" }, { "created": "Fri, 25 Sep 2009 12:22:45 GMT", "version": "v4" } ]
2009-10-29
[ [ "McDonald", "John", "" ] ]
We show that Q-ball decay in Affleck-Dine baryogenesis models can account for dark matter when the annihilation cross-section is sufficiently enhanced to explain the positron and electron excesses observed by PAMELA, ATIC and PPB-BETS. For Affleck-Dine baryogenesis along a d = 6 flat direction, the reheating temperature is approximately 30 GeV and the Q-ball decay temperature is in the range 10-100 MeV. The LSPs produced by Q-ball decay annihilate down to the observed dark matter density if the cross-section is enhanced by a factor ~ 10^3 relative to the thermal relic cross-section.
2012.02186
Bianka Mecaj
Bianka Mecaj and Matthias Neubert
Effective Field Theory for Leptoquarks
5 Figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Leptoquarks enter in several extensions of the Standard Model as possible solutions to a number of observed anomalies. We work within the soft-collinear effective theory framework to present a detailed analysis of the decay rates of the three leptoquarks that appear the most in literature, the scalars $S_1$ and $S_3$ and the vector $U_1^{\mu}$. Using renormalization group methods we resum the large logarithms arising from the evolution of the Wilson coefficients between the New Physics scale and the electroweak scale. We also derive the tree-level matching relations for the Wilson coefficients in the effective theory for some specific leptoquark models.
[ { "created": "Thu, 3 Dec 2020 18:58:41 GMT", "version": "v1" }, { "created": "Tue, 15 Nov 2022 20:48:49 GMT", "version": "v2" } ]
2022-11-17
[ [ "Mecaj", "Bianka", "" ], [ "Neubert", "Matthias", "" ] ]
Leptoquarks enter in several extensions of the Standard Model as possible solutions to a number of observed anomalies. We work within the soft-collinear effective theory framework to present a detailed analysis of the decay rates of the three leptoquarks that appear the most in literature, the scalars $S_1$ and $S_3$ and the vector $U_1^{\mu}$. Using renormalization group methods we resum the large logarithms arising from the evolution of the Wilson coefficients between the New Physics scale and the electroweak scale. We also derive the tree-level matching relations for the Wilson coefficients in the effective theory for some specific leptoquark models.
hep-ph/9407202
Damien Pierce
Damien Pierce
Weak Scale Threshold Corrections in Supersymmetric Models
9 pages, JHU-TIPAC-940010. Talk presented at the SUSY-94 Conference, Ann Arbor, Michigan, May 14--17, 1994. 7 uuencoded postscript figures included. Uncomment the line "%\input epsf" to embed the figures in the text
null
null
null
hep-ph
null
I discuss the weak scale threshold corrections in supersymmetric models. I describe the ``match and run" approximation to the threshold corrections and compare with the exact one-loop results. With explicit examples I show that in cases without large hierarchies in the mass spectra the ``match and run" approximation can lead to order $\cal{O}$(1) errors in the determination of the threshold corrections. I demonstrate how to obtain the threshold-corrected Yukawa coupling from the fermion pole mass. I present corrections to the top quark and squark/slepton masses as a function of the GUT scale parameters $m_0$ and $m_{1/2}$ and show that the gauge/Higgs sector corrections to the top quark mass are small while the gluino correction can be larger than the well known gluon correction.
[ { "created": "Fri, 1 Jul 1994 02:42:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pierce", "Damien", "" ] ]
I discuss the weak scale threshold corrections in supersymmetric models. I describe the ``match and run" approximation to the threshold corrections and compare with the exact one-loop results. With explicit examples I show that in cases without large hierarchies in the mass spectra the ``match and run" approximation can lead to order $\cal{O}$(1) errors in the determination of the threshold corrections. I demonstrate how to obtain the threshold-corrected Yukawa coupling from the fermion pole mass. I present corrections to the top quark and squark/slepton masses as a function of the GUT scale parameters $m_0$ and $m_{1/2}$ and show that the gauge/Higgs sector corrections to the top quark mass are small while the gluino correction can be larger than the well known gluon correction.
1708.09607
Andrej Liptaj
Stanislav Dubnicka, Anna Z. Dubnickova, Aidos Issadykov, Mikhail A. Ivanov, Andrej Liptaj
Study of $B_c$ decays into charmonia and $D$ mesons
15 pages, 2 figures
Phys. Rev. D 96, 076017 (2017)
10.1103/PhysRevD.96.076017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the wake of recent measurements of the decays $B_c^+\to J/\psi D^+_s$ and $B_c^+\to J/\psi D^{\ast\,+}_s$ performed by the LHCb and ATLAS Collaborations, we recalculate their branching fractions in the framework of the covariant confined quark model. We compare the obtained results with available experimental data, our previous findings and numbers from other approaches.
[ { "created": "Thu, 31 Aug 2017 08:11:30 GMT", "version": "v1" } ]
2017-11-01
[ [ "Dubnicka", "Stanislav", "" ], [ "Dubnickova", "Anna Z.", "" ], [ "Issadykov", "Aidos", "" ], [ "Ivanov", "Mikhail A.", "" ], [ "Liptaj", "Andrej", "" ] ]
In the wake of recent measurements of the decays $B_c^+\to J/\psi D^+_s$ and $B_c^+\to J/\psi D^{\ast\,+}_s$ performed by the LHCb and ATLAS Collaborations, we recalculate their branching fractions in the framework of the covariant confined quark model. We compare the obtained results with available experimental data, our previous findings and numbers from other approaches.
hep-ph/9604296
Yasuhiro Okada
Yoshitaka Kuno and Yasuhiro Okada (KEK)
$\mu\to e\gamma$ Search with Polarized Muons
11 pages, 2 figures, also available via anonymous ftp at ftp://ftp.kek.jp/kek/preprints/TH/TH-478
Phys.Rev.Lett. 77 (1996) 434-438
10.1103/PhysRevLett.77.434
KEK TH-478, KEK preprint 96-5
hep-ph
null
A search for the lepton-flavor violating $\mu^{+}\rightarrow e^{+}\gamma$ decay using polarized muons is proposed. By measuring the angular distribution of $e^{+}$s with respect to the muon spin direction, in particular antiparallel $e^{+}$s, the serious physics background from $\mu^{+}\rightarrow e^{+}\nu\overline{\nu}\gamma$ as well as accidental background from normal muon decay accompanied by a high-energy photon can be suppressed significantly. In addition to the enhancement of the sensitivity, the angular distribution would discriminate among different extensions to the Standard Model, once the signal is observed.
[ { "created": "Thu, 11 Apr 1996 15:22:08 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kuno", "Yoshitaka", "", "KEK" ], [ "Okada", "Yasuhiro", "", "KEK" ] ]
A search for the lepton-flavor violating $\mu^{+}\rightarrow e^{+}\gamma$ decay using polarized muons is proposed. By measuring the angular distribution of $e^{+}$s with respect to the muon spin direction, in particular antiparallel $e^{+}$s, the serious physics background from $\mu^{+}\rightarrow e^{+}\nu\overline{\nu}\gamma$ as well as accidental background from normal muon decay accompanied by a high-energy photon can be suppressed significantly. In addition to the enhancement of the sensitivity, the angular distribution would discriminate among different extensions to the Standard Model, once the signal is observed.
1811.07304
Angel Gomez Nicola
S.Ferreres-Sol\'e, A. G\'omez Nicola and A. Vioque-Rodr\'iguez
The role of the thermal $f_0(500)$ in chiral symmetry restoration
18 pages, 9 figures. Comments and references added. Version to appear in Phys.Rev.D
Phys. Rev. D 99, 036018 (2019)
10.1103/PhysRevD.99.036018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the $\sigma/f_0(500)$ state with finite-temperature $T$ corrections to its spectral properties included, plays an essential role for the description of the scalar susceptibility $\chi_S$, signaling chiral symmetry restoration. First, we use the $O(4)$ Linear Sigma Model as a testbed to derive the connection between $\chi_S$ and the $\sigma$ propagator and to check the validity and reliability of the approach where $\chi_S$ is saturated by the $\sigma/f_0(500)$ inverse self-energy, which we calculate at finite $T$ to one loop. A more accurate phenomenological description is achieved by considering the saturation approach as given by the thermal $f_0(500)$ state generated in Unitarized Chiral Perturbation Theory. Such approach allows to describe fairly well recent lattice data within the uncertainty range given by the UChPT parameters. Finally, we compare the UChPT saturated description with one based on the Hadron Resonance Gas, for which the hadron mass dependences are extracted from recent theoretical analysis. Several fits to lattice data are performed, which confirm the validity of the thermal $f_0(500)$ saturated approach and hence the importance of that thermal state for chiral symmetry restoration.
[ { "created": "Sun, 18 Nov 2018 10:09:08 GMT", "version": "v1" }, { "created": "Tue, 26 Feb 2019 19:36:53 GMT", "version": "v2" } ]
2019-03-06
[ [ "Ferreres-Solé", "S.", "" ], [ "Nicola", "A. Gómez", "" ], [ "Vioque-Rodríguez", "A.", "" ] ]
We show that the $\sigma/f_0(500)$ state with finite-temperature $T$ corrections to its spectral properties included, plays an essential role for the description of the scalar susceptibility $\chi_S$, signaling chiral symmetry restoration. First, we use the $O(4)$ Linear Sigma Model as a testbed to derive the connection between $\chi_S$ and the $\sigma$ propagator and to check the validity and reliability of the approach where $\chi_S$ is saturated by the $\sigma/f_0(500)$ inverse self-energy, which we calculate at finite $T$ to one loop. A more accurate phenomenological description is achieved by considering the saturation approach as given by the thermal $f_0(500)$ state generated in Unitarized Chiral Perturbation Theory. Such approach allows to describe fairly well recent lattice data within the uncertainty range given by the UChPT parameters. Finally, we compare the UChPT saturated description with one based on the Hadron Resonance Gas, for which the hadron mass dependences are extracted from recent theoretical analysis. Several fits to lattice data are performed, which confirm the validity of the thermal $f_0(500)$ saturated approach and hence the importance of that thermal state for chiral symmetry restoration.
0905.2801
Toshifumi Yamada
Nobuchika Okada, Toshifumi Yamada
The PAMELA and Fermi signals from long-lived Kaluza-Klein dark matter
9 pages, no figure
Phys.Rev.D80:075010,2009
10.1103/PhysRevD.80.075010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a simple extension of the minimal universal extra dimension (UED)model by introducing a small curvature. The model is formulated as a small anti-de Sitter curvature limit of the five-dimensional standard model (SM) in the Randall-Sundrum background geometry. While the lightest Kaluza-Klein (KK) particle can be thermal relic dark matter as usual in the UED model, the KK-parity is explicitly broken in the presence of the small curvature and the KK dark matter decays into the SM fermions with a long lifetime. Couplings of the KK dark matter with SM fermion pairs in the five dimensional bulk are controlled by fermion bulk masses. With a suitable choice of bulk masses for leptons and quarks, the KK dark matter through its decay into leptons can account for the cosmic-ray electron/positron excesses reported by the recent PAMELA and FERMI satellite experiments, while suppressing the decay into quarks.
[ { "created": "Mon, 18 May 2009 04:29:39 GMT", "version": "v1" }, { "created": "Thu, 27 Aug 2009 08:17:17 GMT", "version": "v2" }, { "created": "Wed, 7 Oct 2009 05:50:14 GMT", "version": "v3" } ]
2009-11-06
[ [ "Okada", "Nobuchika", "" ], [ "Yamada", "Toshifumi", "" ] ]
We propose a simple extension of the minimal universal extra dimension (UED)model by introducing a small curvature. The model is formulated as a small anti-de Sitter curvature limit of the five-dimensional standard model (SM) in the Randall-Sundrum background geometry. While the lightest Kaluza-Klein (KK) particle can be thermal relic dark matter as usual in the UED model, the KK-parity is explicitly broken in the presence of the small curvature and the KK dark matter decays into the SM fermions with a long lifetime. Couplings of the KK dark matter with SM fermion pairs in the five dimensional bulk are controlled by fermion bulk masses. With a suitable choice of bulk masses for leptons and quarks, the KK dark matter through its decay into leptons can account for the cosmic-ray electron/positron excesses reported by the recent PAMELA and FERMI satellite experiments, while suppressing the decay into quarks.
hep-ph/0006093
Enrique Garcia-Reyes
E. Garc\'ia, A. Hern\'andez-Galeana, D. Jaramillo, W. A. Ponce and A. Zepeda
Hierarchical Radiative Quark Mass Matrices with an $U(1)_X$ Horizontal Symmetry Model
10 pages, 5 tables and 3 figures Some comments added to clarify as suggested to publish. Some typing mistakes corrected. Update of Mass and CKM matrix values
Rev.Mex.Fis. 48 (2002) 32-38
null
null
hep-ph
null
In a model with a gauge group $G_{SM}\otimes U(1)_X$, where $G_{SM} \equiv SU(3)_C \otimes SU(2)_L \otimes U(1)_Y$ is the standard model gauge group and $U(1)_X$ is a horizontal local gauge symmetry, we propose a radiative generation of the spectrum of quark masses and mixing angles. The assignment of horizontal charges is such that at tree level only the third family is massive. Using these tree level masses and introducing exotic scalars, the light families of quarks acquire hierarchical masses through radiative corrections. The rank three quark mass matrices obtained are written in terms of a minimal set of free parameters of the model, whose values are estimated performing a numerical fit. The resulting quark masses and CKM mixing angles turn out to be in good agreement with the experimental values.
[ { "created": "Fri, 9 Jun 2000 21:42:31 GMT", "version": "v1" }, { "created": "Tue, 26 Mar 2002 20:00:31 GMT", "version": "v2" } ]
2016-08-15
[ [ "García", "E.", "" ], [ "Hernández-Galeana", "A.", "" ], [ "Jaramillo", "D.", "" ], [ "Ponce", "W. A.", "" ], [ "Zepeda", "A.", "" ] ]
In a model with a gauge group $G_{SM}\otimes U(1)_X$, where $G_{SM} \equiv SU(3)_C \otimes SU(2)_L \otimes U(1)_Y$ is the standard model gauge group and $U(1)_X$ is a horizontal local gauge symmetry, we propose a radiative generation of the spectrum of quark masses and mixing angles. The assignment of horizontal charges is such that at tree level only the third family is massive. Using these tree level masses and introducing exotic scalars, the light families of quarks acquire hierarchical masses through radiative corrections. The rank three quark mass matrices obtained are written in terms of a minimal set of free parameters of the model, whose values are estimated performing a numerical fit. The resulting quark masses and CKM mixing angles turn out to be in good agreement with the experimental values.
hep-ph/9909201
Philip Page
Philip R. Page
Gluonic Excitations' Millennial Finale
7 pages, LaTeX. Four postscript figures. Invited talk at XVth Particles and Nuclei International Conference (PANIC 99), Uppsala, Sweden, 10-16 June 1999. To be published by World Scientific (Singapore)
Nucl.Phys.A663:585-591,2000
10.1016/S0375-9474(99)00661-2
LA-UR-99-4707
hep-ph hep-lat
null
We provide an overview of theoretical developments on hybrid mesons and glueballs in the last year at this turn of the millenium conference. Cracks in potential models of conventional mesons are developing. Hybrid meson adiabatic surfaces have been calculated and interpreted, experimental J^PC exotics have hybrid meson, four-quark state or non-resonant interpretations, and the strong decay mechanism of hybrids has been studied. All theoretical progress on hybrid mesons in the last year is mentioned. Overall features of glueballs are visited: decays and the successes of the large N_c limit. Two promising experimental areas are mentioned: charmonium hybrids at B-factories and s sbar hybrids at Jefferson Lab.
[ { "created": "Wed, 1 Sep 1999 00:06:09 GMT", "version": "v1" }, { "created": "Mon, 4 Oct 1999 16:37:28 GMT", "version": "v2" } ]
2014-11-17
[ [ "Page", "Philip R.", "" ] ]
We provide an overview of theoretical developments on hybrid mesons and glueballs in the last year at this turn of the millenium conference. Cracks in potential models of conventional mesons are developing. Hybrid meson adiabatic surfaces have been calculated and interpreted, experimental J^PC exotics have hybrid meson, four-quark state or non-resonant interpretations, and the strong decay mechanism of hybrids has been studied. All theoretical progress on hybrid mesons in the last year is mentioned. Overall features of glueballs are visited: decays and the successes of the large N_c limit. Two promising experimental areas are mentioned: charmonium hybrids at B-factories and s sbar hybrids at Jefferson Lab.
1103.1747
Andrey Tarasov
M.A.Braun, A.N.Tarasov
BFKL pomeron propagator in the external field of the nucleus
17 pages, 15 figures
Nucl.Phys.B851:533-550,2011
10.1016/j.nuclphysb.2011.06.005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown by numerical calculations that the convoluted QCD pomeron propagator in the external field created by a solution of the Balitsky-Kovchegov equation in the nuclear matter vanishes at high rapidities. This may open a possibility to apply the perturbative approach for the calculation of pomeron loops.
[ { "created": "Wed, 9 Mar 2011 10:03:41 GMT", "version": "v1" }, { "created": "Fri, 11 Mar 2011 17:38:14 GMT", "version": "v2" } ]
2015-03-19
[ [ "Braun", "M. A.", "" ], [ "Tarasov", "A. N.", "" ] ]
It is shown by numerical calculations that the convoluted QCD pomeron propagator in the external field created by a solution of the Balitsky-Kovchegov equation in the nuclear matter vanishes at high rapidities. This may open a possibility to apply the perturbative approach for the calculation of pomeron loops.
2312.13149
Alejandro Szynkman
Leandro Da Rold, Manuel Epele, Anibal D. Medina, Nicol\'as I. Mileo, Alejandro Szynkman
Double Higgs production at the HL-LHC: probing a loop-enhanced model with kinematical distributions
23 pages, 7 figures: version accepted for publication
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We study di-Higgs production via gluon fusion at the high luminosity LHC in the presence of new physics, focusing on the $b\bar b\gamma\gamma$ final states. Taking a minimal set of three scalar leptoquarks (LQs) with cubic and quartic interactions with the Higgs and choosing four benchmark points with a light LQ, we perform a detailed analysis of differential distributions of the di-Higgs production cross section, studying the imprints of the new physics states running in the loops. Simulating the signal and main backgrounds, we study the influence of the new physics in differential distributions such as the invariant mass of the subsystems of final particles, the transverse momentum, and angular variables, finding in particular a resonance peak associated with the light LQ. It turns out that the angular separation of the photons, which is correlated with the resonance LQ peak, is a very sensitive observable that helps in discriminating the new physics signal from the Standard Model background. We find that for two of our benchmarks discovery could be reached with 3 ab$^{-1}$, whereas exclusion limits at 95% C.L. could be claimed with 0.60-0.75 ab$^{-1}$. For the other two benchmarks that have heavier LQ masses significances of order 2$\sigma$ are possible for 3 ab$^{-1}$. A similar analysis could be applied to other loop-enhanced models.
[ { "created": "Wed, 20 Dec 2023 16:13:09 GMT", "version": "v1" }, { "created": "Wed, 24 Apr 2024 13:48:21 GMT", "version": "v2" } ]
2024-04-30
[ [ "Da Rold", "Leandro", "" ], [ "Epele", "Manuel", "" ], [ "Medina", "Anibal D.", "" ], [ "Mileo", "Nicolás I.", "" ], [ "Szynkman", "Alejandro", "" ] ]
We study di-Higgs production via gluon fusion at the high luminosity LHC in the presence of new physics, focusing on the $b\bar b\gamma\gamma$ final states. Taking a minimal set of three scalar leptoquarks (LQs) with cubic and quartic interactions with the Higgs and choosing four benchmark points with a light LQ, we perform a detailed analysis of differential distributions of the di-Higgs production cross section, studying the imprints of the new physics states running in the loops. Simulating the signal and main backgrounds, we study the influence of the new physics in differential distributions such as the invariant mass of the subsystems of final particles, the transverse momentum, and angular variables, finding in particular a resonance peak associated with the light LQ. It turns out that the angular separation of the photons, which is correlated with the resonance LQ peak, is a very sensitive observable that helps in discriminating the new physics signal from the Standard Model background. We find that for two of our benchmarks discovery could be reached with 3 ab$^{-1}$, whereas exclusion limits at 95% C.L. could be claimed with 0.60-0.75 ab$^{-1}$. For the other two benchmarks that have heavier LQ masses significances of order 2$\sigma$ are possible for 3 ab$^{-1}$. A similar analysis could be applied to other loop-enhanced models.
hep-ph/9803452
Marcio Jose Menon
P.C Beggio, M. J. Menon and P. Valin
Hadronic and elementary multiplicity distributions in a geometrical approach
4 pages, 4 embeded figures, aps-revtex. Replaced with several changes (manuscript and figures). To be published Proc. Int. Conf. on Elastic and Diffractive Scattering (VIIIth "Blois Workshop"), Protvino
null
null
IFGW-DRCC 99/09
hep-ph hep-ex
null
We construct the hadronic multiplicity distribution in terms of an elementary distribution (at given impact parameter) and the inelastic overlap function characterized by the observed BEL (Blacker-Edgier-Larger) behaviour. With suitable parametrizations for the elementary quantities, based on some geometrical arguments and the most recent data on e+e- annihilation, an excellent description of pp and p(bar)p inelastic multiplicity distributions at the highest energies is obtained.
[ { "created": "Wed, 25 Mar 1998 21:48:39 GMT", "version": "v1" }, { "created": "Wed, 22 Sep 1999 19:31:41 GMT", "version": "v2" } ]
2007-05-23
[ [ "Beggio", "P. C", "" ], [ "Menon", "M. J.", "" ], [ "Valin", "P.", "" ] ]
We construct the hadronic multiplicity distribution in terms of an elementary distribution (at given impact parameter) and the inelastic overlap function characterized by the observed BEL (Blacker-Edgier-Larger) behaviour. With suitable parametrizations for the elementary quantities, based on some geometrical arguments and the most recent data on e+e- annihilation, an excellent description of pp and p(bar)p inelastic multiplicity distributions at the highest energies is obtained.
hep-ph/0311108
Shi-Lin Zhu
Peng-Zhi Huang, Wei-Zhen Deng, Xiao-Lin Chen and Shi-Lin Zhu (Peking University)
Magnetic Moment of The $\Theta^+$ Pentaquark State
1 eps figure, 13 pages
Phys.Rev. D69 (2004) 074004
10.1103/PhysRevD.69.074004
null
hep-ph hep-ex nucl-ex nucl-th
null
We have calculated the magnetic moment of the recently observed $\Theta^+$ pentaquark in the framework of the light cone QCD sum rules using the photon distribution amplitudes. We find that $\mu_{\Theta^+}=(0.12\pm 0.06) \mu_N$, which is quite small. We also compare our result with predictions of other groups.
[ { "created": "Mon, 10 Nov 2003 03:41:55 GMT", "version": "v1" }, { "created": "Sat, 10 Jan 2004 01:33:41 GMT", "version": "v2" } ]
2009-11-10
[ [ "Huang", "Peng-Zhi", "", "Peking\n University" ], [ "Deng", "Wei-Zhen", "", "Peking\n University" ], [ "Chen", "Xiao-Lin", "", "Peking\n University" ], [ "Zhu", "Shi-Lin", "", "Peking\n University" ] ]
We have calculated the magnetic moment of the recently observed $\Theta^+$ pentaquark in the framework of the light cone QCD sum rules using the photon distribution amplitudes. We find that $\mu_{\Theta^+}=(0.12\pm 0.06) \mu_N$, which is quite small. We also compare our result with predictions of other groups.
1009.1331
Bo-Qiang Ma
Zhou Lingli, Bo-Qiang Ma
Lorentz Invariance Violation Matrix from a General Principle
10 pages, no figure
Mod.Phys.Lett.A25:2489-2499,2010
10.1142/S0217732310033761
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that a general principle of physical independence or physical invariance of mathematical background manifold leads to a replacement of the common derivative operators by the covariant co-derivative ones. This replacement naturally induces a background matrix, by means of which we obtain an effective Lagrangian for the minimal standard model with supplement terms characterizing Lorentz invariance violation or anisotropy of space-time. We construct a simple model of the background matrix and find that the strength of Lorentz violation of proton in the photopion production is of the order $10^{-23}$.
[ { "created": "Tue, 7 Sep 2010 16:25:27 GMT", "version": "v1" } ]
2011-10-17
[ [ "Lingli", "Zhou", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We show that a general principle of physical independence or physical invariance of mathematical background manifold leads to a replacement of the common derivative operators by the covariant co-derivative ones. This replacement naturally induces a background matrix, by means of which we obtain an effective Lagrangian for the minimal standard model with supplement terms characterizing Lorentz invariance violation or anisotropy of space-time. We construct a simple model of the background matrix and find that the strength of Lorentz violation of proton in the photopion production is of the order $10^{-23}$.
hep-ph/0008101
Andre Hoang
A. H. Hoang (CERN)
Non-Relativistic Effective Field Theory for Perturbative Heavy Quark--Antiquark Systems
15 pages, latex (sprocl.sty), 2 postscript figures. Invited talk presented at the 5th Workshop on QCD (QCD 2000), Villefranche-sur-Mer, France, 3-7 Jan 2000
null
null
CERN-TH/2000-143
hep-ph
null
Recent developments for an effective theory for non-relativistic perturbative quark-antiquark systems are reviewed and some applications are discussed.
[ { "created": "Thu, 10 Aug 2000 19:31:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hoang", "A. H.", "", "CERN" ] ]
Recent developments for an effective theory for non-relativistic perturbative quark-antiquark systems are reviewed and some applications are discussed.
0806.3307
Nicole F. Bell
Nicole F. Bell, Boris J. Kayser, and Sandy S. C. Law
Electromagnetic Leptogenesis
6 pages, 6 figures; v2: some references added, minor change to discussion, accepted by PRD
Phys.Rev.D78:085024,2008
10.1103/PhysRevD.78.085024
FERMILAB-PUB-08/186-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new leptogenesis scenario, where the lepton asymmetry is generated by CP violating decays of heavy electroweak singlet neutrinos via electromagnetic dipole moment couplings to the ordinary light neutrinos. Akin to the usual scenario where the decays are mediated through Yukawa interactions, we have shown, by explicit calculations, that the desired asymmetry can be produced through the interference of the corresponding tree-level and one-loop decay amplitudes involving the effective dipole moment operators. We also find that the relationship of the leptogenesis scale to the light neutrino masses is similar to that for the standard Yukawa-mediated mechanism.
[ { "created": "Fri, 20 Jun 2008 02:36:51 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 2008 05:28:44 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bell", "Nicole F.", "" ], [ "Kayser", "Boris J.", "" ], [ "Law", "Sandy S. C.", "" ] ]
We present a new leptogenesis scenario, where the lepton asymmetry is generated by CP violating decays of heavy electroweak singlet neutrinos via electromagnetic dipole moment couplings to the ordinary light neutrinos. Akin to the usual scenario where the decays are mediated through Yukawa interactions, we have shown, by explicit calculations, that the desired asymmetry can be produced through the interference of the corresponding tree-level and one-loop decay amplitudes involving the effective dipole moment operators. We also find that the relationship of the leptogenesis scale to the light neutrino masses is similar to that for the standard Yukawa-mediated mechanism.
hep-ph/0507198
John Conley
John A. Conley, JoAnne Hewett, and My Phuong Le (Stanford Linear Accelerator Center)
Determination of Littlest Higgs model parameters at the ILC
21 pages, 15 Postscript figures
Phys.Rev.D72:115014,2005
10.1103/PhysRevD.72.115014
SLAC-PUB-11344
hep-ph
null
We examine the effects of the extended gauge sector of the Littlest Higgs model in high energy e+e- collisions. We find that the search reach in e+e- -> f fbar at a 500 GeV center-of-mass energy International Linear Collider covers essentially the entire parameter region where the Littlest Higgs model is relevant to the gauge hierarchy problem. In addition, we show that this channel provides an accurate determination of the fundamental model parameters, to the precision of a few percent, provided that the LHC measures the mass of the heavy neutral gauge field. Additionally, we show that the couplings of the extra gauge bosons to the light Higgs can be observed from the process e+e- -> Z higgs for a significant region of the parameter space. This allows for confirmation of the structure of the cancelation of the Higgs mass quadratic divergence and would verify the little Higgs mechanism.
[ { "created": "Fri, 15 Jul 2005 19:48:57 GMT", "version": "v1" }, { "created": "Wed, 30 Nov 2005 01:22:37 GMT", "version": "v2" } ]
2008-11-26
[ [ "Conley", "John A.", "", "Stanford Linear\n Accelerator Center" ], [ "Hewett", "JoAnne", "", "Stanford Linear\n Accelerator Center" ], [ "Le", "My Phuong", "", "Stanford Linear\n Accelerator Center" ] ]
We examine the effects of the extended gauge sector of the Littlest Higgs model in high energy e+e- collisions. We find that the search reach in e+e- -> f fbar at a 500 GeV center-of-mass energy International Linear Collider covers essentially the entire parameter region where the Littlest Higgs model is relevant to the gauge hierarchy problem. In addition, we show that this channel provides an accurate determination of the fundamental model parameters, to the precision of a few percent, provided that the LHC measures the mass of the heavy neutral gauge field. Additionally, we show that the couplings of the extra gauge bosons to the light Higgs can be observed from the process e+e- -> Z higgs for a significant region of the parameter space. This allows for confirmation of the structure of the cancelation of the Higgs mass quadratic divergence and would verify the little Higgs mechanism.
hep-ph/0408276
Toshihiko Ota
Shinya Kanemura, Koichi Matsuda, Toshihiko Ota, Tetsuo Shindou, Eiichi Takasugi, Koji Tsumura
Lepton Flavor Violation in the Higgs Boson Decay at a Linear Collider
Proceedings for the Linear Collider Workshop (LCWS2004) in Paris, France, April 19-23, 2004, Talk given by T. Ota, 4 pages, 2 figures
null
null
null
hep-ph
null
We study possibility of observing the process $h^{0} \to \tau^{\pm} \mu^{\mp}$ at a linear collider. The branching ratio is constrained to be of the order of $10^{-4}$ by the $\tau^{-} \to \mu^{-} \eta$ result. Supersymmetric standard models can reproduce such amount of the branching ratio by taking a specific parameter set. The Higgsstrahlung process $e^{+}e^{-} \to Zh^{0}$ is preferable because of its simple kinematic structure, then, the signal process is $e^{+} e^{-} \to Z h^{0} \to Z \tau^{\pm} \mu^{\mp}$. The most serious background comes from the process, $e^{+} e^{-} \to Zh^{0} \to Z\tau^{\pm} \tau^{\mp} \to \tau^{\pm} \mu^{\mp} \nu \bar{\nu}$. We estimate the significance of the signal, taking into account the background reduction.
[ { "created": "Wed, 25 Aug 2004 10:07:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kanemura", "Shinya", "" ], [ "Matsuda", "Koichi", "" ], [ "Ota", "Toshihiko", "" ], [ "Shindou", "Tetsuo", "" ], [ "Takasugi", "Eiichi", "" ], [ "Tsumura", "Koji", "" ] ]
We study possibility of observing the process $h^{0} \to \tau^{\pm} \mu^{\mp}$ at a linear collider. The branching ratio is constrained to be of the order of $10^{-4}$ by the $\tau^{-} \to \mu^{-} \eta$ result. Supersymmetric standard models can reproduce such amount of the branching ratio by taking a specific parameter set. The Higgsstrahlung process $e^{+}e^{-} \to Zh^{0}$ is preferable because of its simple kinematic structure, then, the signal process is $e^{+} e^{-} \to Z h^{0} \to Z \tau^{\pm} \mu^{\mp}$. The most serious background comes from the process, $e^{+} e^{-} \to Zh^{0} \to Z\tau^{\pm} \tau^{\mp} \to \tau^{\pm} \mu^{\mp} \nu \bar{\nu}$. We estimate the significance of the signal, taking into account the background reduction.
1512.02190
C. Hanhart
C. Hanhart
Amplitude Analysis for Mesons and Baryons: Tools and Technology
8 pages; proceedings of the XVIth International Conference on Hadron Spectroscopy (Hadron 2015)
null
10.1063/1.4949383
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In these proceedings some facts about resonances are discussed focussing on the analytic properties of resonant amplitudes with special emphasis on model independent analyses. As an illustrative example of the latter point the decays B and B_s to J/psi pi pi are discussed in some detail.
[ { "created": "Mon, 7 Dec 2015 20:13:15 GMT", "version": "v1" } ]
2016-06-22
[ [ "Hanhart", "C.", "" ] ]
In these proceedings some facts about resonances are discussed focussing on the analytic properties of resonant amplitudes with special emphasis on model independent analyses. As an illustrative example of the latter point the decays B and B_s to J/psi pi pi are discussed in some detail.
hep-ph/9903296
Klaus Werner
H.J. Drescher, M. Hladik, S. Ostapchenko, K. Werner
A Unified Treatment of High Energy Interactions
4 pages, LaTeX created with LyX, 8 figures, more figures at http://www-subatech.in2p3.fr/~theo/nexus/examples
J.Phys. G25 (1999) L91-L96
10.1088/0954-3899/25/10/101
SUBATECH 99-03
hep-ph
null
It is well known that high energy interactions as different as electron-positron annihilation, deep inelastic lepton-nucleon scattering, proton-proton interactions, and nucleus-nucleus collisions have many features in common. Based upon this observation, we construct a model for all these interactions, which relies on the fundamental hypothesis that the behavior of high energy interactions is universal.
[ { "created": "Tue, 9 Mar 1999 12:52:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Drescher", "H. J.", "" ], [ "Hladik", "M.", "" ], [ "Ostapchenko", "S.", "" ], [ "Werner", "K.", "" ] ]
It is well known that high energy interactions as different as electron-positron annihilation, deep inelastic lepton-nucleon scattering, proton-proton interactions, and nucleus-nucleus collisions have many features in common. Based upon this observation, we construct a model for all these interactions, which relies on the fundamental hypothesis that the behavior of high energy interactions is universal.
hep-ph/9910463
Nikolai Romanenko
Jukka Maalampi and Nikolai Romanenko (Theoretical Physics Division, Department of Physics, University of Helsinki, Finland)
Production of four jets in LR model
3 pages including 2 figures, ps no figures
null
null
HIP-99-67/TH
hep-ph
null
We consider the reaction ee -> q,q,qbar,qbar as a test of lepton number non-conservation in the framework of the left-right-symmetric electroweak model. The main contributions to this process are due to Majorana neutrino exchange in t-channel and doubly charged Higgs (Delta(--)) exchange in s-channel with a pair of right-handed weak bosons (WR) as intermediate state. We show that in a linear ee collider with the collision energy of 1 TeV (1.5 TeV) the cross section of this process is 0.01 fb (1 fb), and it will, for the anticipated luminosity of 10**35 cm**(-2)s**(-1), be detectable below the WR threshold. We study the sensitivity of the reaction on the masses of the heavy neutrino, WR and Delta(--).
[ { "created": "Sun, 24 Oct 1999 14:50:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Maalampi", "Jukka", "", "Theoretical Physics Division,\n Department of Physics, University of Helsinki, Finland" ], [ "Romanenko", "Nikolai", "", "Theoretical Physics Division,\n Department of Physics, University of Helsinki, Finland" ] ]
We consider the reaction ee -> q,q,qbar,qbar as a test of lepton number non-conservation in the framework of the left-right-symmetric electroweak model. The main contributions to this process are due to Majorana neutrino exchange in t-channel and doubly charged Higgs (Delta(--)) exchange in s-channel with a pair of right-handed weak bosons (WR) as intermediate state. We show that in a linear ee collider with the collision energy of 1 TeV (1.5 TeV) the cross section of this process is 0.01 fb (1 fb), and it will, for the anticipated luminosity of 10**35 cm**(-2)s**(-1), be detectable below the WR threshold. We study the sensitivity of the reaction on the masses of the heavy neutrino, WR and Delta(--).
2111.13520
Peter Vander Griend
Peter Vander Griend
Bottomonium observables in an open quantum system using the quantum trajectories method
8 pages, 3 figures, contribution to the proceedings of A Virtual Tribute to Quark Confinement and the Hadron Spectrum, 2-6 August 2021
null
10.1051/epjconf/202225805005
TUM-EFT 159/21
hep-ph nucl-ex nucl-th physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We solve the Lindblad equation describing the Brownian motion of a Coulombic heavy quark-antiquark pair in a strongly coupled quark gluon plasma using the Monte Carlo wave function method. The Lindblad equation has been derived in the framework of pNRQCD and fully accounts for the quantum and non-Abelian nature of the system. The hydrodynamics of the plasma is realistically implemented through a 3+1D dissipative hydrodynamics code. We compute the bottomonium nuclear modification factor and elliptic flow and compare with the most recent LHC data. The computation does not rely on any free parameter, as it depends on two transport coefficients that have been evaluated independently in lattice QCD. Our final results, which include late-time feed down of excited states, agree well with the available data from LHC 5.02 TeV PbPb collisions.
[ { "created": "Fri, 26 Nov 2021 14:37:32 GMT", "version": "v1" } ]
2022-02-16
[ [ "Griend", "Peter Vander", "" ] ]
We solve the Lindblad equation describing the Brownian motion of a Coulombic heavy quark-antiquark pair in a strongly coupled quark gluon plasma using the Monte Carlo wave function method. The Lindblad equation has been derived in the framework of pNRQCD and fully accounts for the quantum and non-Abelian nature of the system. The hydrodynamics of the plasma is realistically implemented through a 3+1D dissipative hydrodynamics code. We compute the bottomonium nuclear modification factor and elliptic flow and compare with the most recent LHC data. The computation does not rely on any free parameter, as it depends on two transport coefficients that have been evaluated independently in lattice QCD. Our final results, which include late-time feed down of excited states, agree well with the available data from LHC 5.02 TeV PbPb collisions.
1507.02031
Rui-Lin Zhu
Ruilin Zhu
The Exclusive Decay of Upsilon into $h_c$, the $X(3940)$ and $X(4160)$
8 pages, 1 figure and 2 tables, published version in PRD
Phys. Rev. D 92, 074017 (2015)
10.1103/PhysRevD.92.074017
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study double charmonia production in Upsilon peaks, especially, a S-wave charmonium $\eta_c$ and a P-wave charmonium $h_c(^1P_1)$, or a S-wave charmonium $J/\psi$ and the $X(3940)$ and $X(4160)$ within the nonrelativistic QCD (NRQCD) approach which is a powerful tool to realize the factorization of double charmonia production in electron-positron annihilation. The $J^{PC}=1^{--}$ state $\Upsilon(nS)$ can provide an ideal laboratory for studying the properties of double-heavy quarkonium and also can separate the perturbative and nonperturbative parts due to the large heavy quark mass compared with the typical hadron scale $\Lambda_{QCD}$. Explanation of the $X(3940)$ and $X(4160)$ as the $3 ^1S_0$ and $4 ^1S_0$ states, respectively, are compatible with the observed upper limits for the branching fractions of $\Upsilon(1S,2S)\to J/\psi+X$, where $X=X(3940)$, $X(4160)$ by the Belle Collaboration. The branching fractions of $\Upsilon(1S,2S,3S)\to \eta_c+h_c(^1P_1)$ are predicted to be around $10^{-6}$, which shall be tested in Belle-II experiments.
[ { "created": "Wed, 8 Jul 2015 05:48:07 GMT", "version": "v1" }, { "created": "Tue, 18 Aug 2015 02:38:25 GMT", "version": "v2" }, { "created": "Tue, 13 Oct 2015 13:09:40 GMT", "version": "v3" } ]
2015-10-21
[ [ "Zhu", "Ruilin", "" ] ]
In this paper, we study double charmonia production in Upsilon peaks, especially, a S-wave charmonium $\eta_c$ and a P-wave charmonium $h_c(^1P_1)$, or a S-wave charmonium $J/\psi$ and the $X(3940)$ and $X(4160)$ within the nonrelativistic QCD (NRQCD) approach which is a powerful tool to realize the factorization of double charmonia production in electron-positron annihilation. The $J^{PC}=1^{--}$ state $\Upsilon(nS)$ can provide an ideal laboratory for studying the properties of double-heavy quarkonium and also can separate the perturbative and nonperturbative parts due to the large heavy quark mass compared with the typical hadron scale $\Lambda_{QCD}$. Explanation of the $X(3940)$ and $X(4160)$ as the $3 ^1S_0$ and $4 ^1S_0$ states, respectively, are compatible with the observed upper limits for the branching fractions of $\Upsilon(1S,2S)\to J/\psi+X$, where $X=X(3940)$, $X(4160)$ by the Belle Collaboration. The branching fractions of $\Upsilon(1S,2S,3S)\to \eta_c+h_c(^1P_1)$ are predicted to be around $10^{-6}$, which shall be tested in Belle-II experiments.
hep-ph/9603433
Chung Kao
Salavat Abdullin, Howard Baer, Chung Kao, Nikita Stepanov and Xerxes Tata
Simultaneous Search for Two Higgs Bosons of Minimal Supersymmetry at the LHC
17 pages, REVTEX, 6 figures
Phys.Rev.D54:6728-6734,1996
10.1103/PhysRevD.54.6728
FSUHEP-960315, UR-1457, UH-511-845-96
hep-ph
null
The prospects of detecting the CP-odd Higgs pseudoscalar ($A$) in the minimal supersymmetric model via its decay into a $Z$ boson and the lighter CP-even Higgs scalar ($h$) at the CERN Large Hadron Collider are investigated. The final state of $Z \to l^+l^-$ and $h \to b\bar{b}$, may provide a promising way to simultaneously detect the $A$ and the $h$. The compact muon solenoid detector performance is adopted for a realistic study of observability. In this discovery channel, the masses of the $h$ and the $A$ can be reconstructed. The impact of supersymmetric decay modes is considered.
[ { "created": "Thu, 28 Mar 1996 23:09:10 GMT", "version": "v1" } ]
2008-11-26
[ [ "Abdullin", "Salavat", "" ], [ "Baer", "Howard", "" ], [ "Kao", "Chung", "" ], [ "Stepanov", "Nikita", "" ], [ "Tata", "Xerxes", "" ] ]
The prospects of detecting the CP-odd Higgs pseudoscalar ($A$) in the minimal supersymmetric model via its decay into a $Z$ boson and the lighter CP-even Higgs scalar ($h$) at the CERN Large Hadron Collider are investigated. The final state of $Z \to l^+l^-$ and $h \to b\bar{b}$, may provide a promising way to simultaneously detect the $A$ and the $h$. The compact muon solenoid detector performance is adopted for a realistic study of observability. In this discovery channel, the masses of the $h$ and the $A$ can be reconstructed. The impact of supersymmetric decay modes is considered.
1010.5230
Masaki Asano
Masaki Asano, Yasuhiro Shimizu
Measurements of neutral vector resonance in Higgsless models at the LHC
16 pages, 6 figures, 5 tables; v2: references added, minor corrections, version published in JHEP
JHEP 1101:124,2011
10.1007/JHEP01(2011)124
TU-874
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Higgsless models, new vector resonances appear to restore the unitarity of the W_L W_L scattering amplitude without the Higgs boson. In the ideal delocalized three site Higgsless model, one of large prodcution cross section of the neutral vector resonance (Z') at the Large Hadron Collider is the W-associated production, pp \to Z'W \to WWW. Although the dileptonic decay channnel, l\nu l'\nu 'jj, is experimentally clean to search for the Z' signals, it is difficult to reconstruct the Z' invariant mass due to the two neutrinos in the final state. We study collider signatures of Z' using the M_{T2}-Assisted On-Shell (MAOS) reconstruction of the missing neutrino momenta. We show the prospect of the Z' mass determination in the channel, l\nu l'\nu 'jj, at the Large Hadron Collider.
[ { "created": "Mon, 25 Oct 2010 19:50:31 GMT", "version": "v1" }, { "created": "Wed, 26 Jan 2011 09:10:12 GMT", "version": "v2" } ]
2015-03-17
[ [ "Asano", "Masaki", "" ], [ "Shimizu", "Yasuhiro", "" ] ]
In Higgsless models, new vector resonances appear to restore the unitarity of the W_L W_L scattering amplitude without the Higgs boson. In the ideal delocalized three site Higgsless model, one of large prodcution cross section of the neutral vector resonance (Z') at the Large Hadron Collider is the W-associated production, pp \to Z'W \to WWW. Although the dileptonic decay channnel, l\nu l'\nu 'jj, is experimentally clean to search for the Z' signals, it is difficult to reconstruct the Z' invariant mass due to the two neutrinos in the final state. We study collider signatures of Z' using the M_{T2}-Assisted On-Shell (MAOS) reconstruction of the missing neutrino momenta. We show the prospect of the Z' mass determination in the channel, l\nu l'\nu 'jj, at the Large Hadron Collider.
hep-ph/9604240
Luca Silvestrini
M. Ciuchini, E. Franco, G. Martinelli and L. Silvestrini
Two-body non-leptonic decays on the lattice
15 pages, 1 Postscript figure
Phys.Lett. B380 (1996) 353-362
10.1016/0370-2693(96)00529-1
CERN-TH/96-31
hep-ph hep-lat
null
We show that, under reasonable hypotheses, it is possible to study two-body non-leptonic weak decays in numerical simulations of lattice QCD. By assuming that final-state interactions are dominated by the nearby resonances and that the couplings of the resonances to the final particles are smooth functions of the external momenta, it is possible indeed to overcome the difficulties imposed by the Maiani-Testa no-go theorem and to extract the weak decay amplitudes, including their phases. Under the same assumptions, results can be obtained also for time-like form factors and quasi-elastic processes.
[ { "created": "Thu, 4 Apr 1996 08:16:08 GMT", "version": "v1" } ]
2009-10-28
[ [ "Ciuchini", "M.", "" ], [ "Franco", "E.", "" ], [ "Martinelli", "G.", "" ], [ "Silvestrini", "L.", "" ] ]
We show that, under reasonable hypotheses, it is possible to study two-body non-leptonic weak decays in numerical simulations of lattice QCD. By assuming that final-state interactions are dominated by the nearby resonances and that the couplings of the resonances to the final particles are smooth functions of the external momenta, it is possible indeed to overcome the difficulties imposed by the Maiani-Testa no-go theorem and to extract the weak decay amplitudes, including their phases. Under the same assumptions, results can be obtained also for time-like form factors and quasi-elastic processes.
1001.1341
Peihong Gu
Pei-Hong Gu
A Left-Right Symmetric Model for Neutrino Masses, Baryon Asymmetry and Dark Matter
6 pages. Title changed. Minor corrections. To appear in PRD
Phys.Rev.D81:095002,2010
10.1103/PhysRevD.81.095002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the left-right symmetric models without bi-doublet Higgs scalars, the standard model fermions can obtain masses by integrating out heavy charged singlet fermions. We find the decays of heavy neutral singlet fermions, responsible for generating small neutrino masses, can simultaneously produce a left-handed lepton asymmetry for baryon asymmetry and a relic density of right-handed neutrinos for dark matter. Benefited from the left-right symmetry, the properties of the dark matter can be related to the generation of the neutrino masses and the baryon asymmetry. We also indicate that the decays of the non-thermally produced right-handed neutrinos can explain the observed fluxes of 511 keV photons from the Galactic bulge.
[ { "created": "Fri, 8 Jan 2010 19:17:16 GMT", "version": "v1" }, { "created": "Sun, 10 Jan 2010 07:10:13 GMT", "version": "v2" }, { "created": "Tue, 12 Jan 2010 11:30:30 GMT", "version": "v3" }, { "created": "Thu, 21 Jan 2010 16:54:00 GMT", "version": "v4" }, { "created": "Thu, 15 Apr 2010 08:31:58 GMT", "version": "v5" } ]
2010-05-19
[ [ "Gu", "Pei-Hong", "" ] ]
In the left-right symmetric models without bi-doublet Higgs scalars, the standard model fermions can obtain masses by integrating out heavy charged singlet fermions. We find the decays of heavy neutral singlet fermions, responsible for generating small neutrino masses, can simultaneously produce a left-handed lepton asymmetry for baryon asymmetry and a relic density of right-handed neutrinos for dark matter. Benefited from the left-right symmetry, the properties of the dark matter can be related to the generation of the neutrino masses and the baryon asymmetry. We also indicate that the decays of the non-thermally produced right-handed neutrinos can explain the observed fluxes of 511 keV photons from the Galactic bulge.
0710.4091
Ernesto Arganda
E. Arganda and M.J. Herrero
Lepton Flavour Violation in SUSY-seesaw: an update
To appear in the proceedings of 15th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY07), Karlsruhe, Germany, 26 Jul - 1 Aug 2007. 4 pages, 8 figures
null
null
null
hep-ph
null
Here we update the predictions for lepton flavour violating tau and muon decays, $l_j \to l_i \gamma$, $l_j \to 3 l_i$, and $\mu-e$ conversion in nuclei. We work within a SUSY-seesaw context where the particle content of the Minimal Supersymmetric Standard Model is extended by three right handed neutrinos plus their corresponding SUSY partners, and where a seesaw mechanism for neutrino mass generation is implemented. Two different scenarios with either universal or non-universal soft supersymmetry breaking Higgs masses at the gauge coupling unification scale are considered. After comparing the predictions with present experimental bounds and future sensitivities, the most promising processes are particularly emphasised.
[ { "created": "Mon, 22 Oct 2007 16:22:57 GMT", "version": "v1" } ]
2007-10-23
[ [ "Arganda", "E.", "" ], [ "Herrero", "M. J.", "" ] ]
Here we update the predictions for lepton flavour violating tau and muon decays, $l_j \to l_i \gamma$, $l_j \to 3 l_i$, and $\mu-e$ conversion in nuclei. We work within a SUSY-seesaw context where the particle content of the Minimal Supersymmetric Standard Model is extended by three right handed neutrinos plus their corresponding SUSY partners, and where a seesaw mechanism for neutrino mass generation is implemented. Two different scenarios with either universal or non-universal soft supersymmetry breaking Higgs masses at the gauge coupling unification scale are considered. After comparing the predictions with present experimental bounds and future sensitivities, the most promising processes are particularly emphasised.
2311.14365
Jing Song
Hai-Peng Li, Jing Song, Wei-Hong Liang, R. Molina, E. Oset
Contrasting observables related to the $N^*(1535)$ from the molecular or a genuine structure
null
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we compare the predictions for the scattering length and effective range of the channels $K^0 \Sigma^+, K^+ \Sigma^0 , K^+ \Lambda$ and $\eta p$, assuming the $N^*(1535)$ state as a molecular state of these channels, or an original genuine state, made for instance from three quarks. Looking at very different scenarios, what we conclude is that the predictions of these two pictures are drastically different, to the point that we advise the measurement of these magnitudes, accessible for instance by measuring correlation functions, in order to gain much valuable information concerning the nature of this state.
[ { "created": "Fri, 24 Nov 2023 09:22:06 GMT", "version": "v1" }, { "created": "Tue, 28 Nov 2023 13:14:58 GMT", "version": "v2" }, { "created": "Mon, 4 Dec 2023 10:15:56 GMT", "version": "v3" }, { "created": "Thu, 8 Feb 2024 16:13:16 GMT", "version": "v4" } ]
2024-02-09
[ [ "Li", "Hai-Peng", "" ], [ "Song", "Jing", "" ], [ "Liang", "Wei-Hong", "" ], [ "Molina", "R.", "" ], [ "Oset", "E.", "" ] ]
In this work we compare the predictions for the scattering length and effective range of the channels $K^0 \Sigma^+, K^+ \Sigma^0 , K^+ \Lambda$ and $\eta p$, assuming the $N^*(1535)$ state as a molecular state of these channels, or an original genuine state, made for instance from three quarks. Looking at very different scenarios, what we conclude is that the predictions of these two pictures are drastically different, to the point that we advise the measurement of these magnitudes, accessible for instance by measuring correlation functions, in order to gain much valuable information concerning the nature of this state.
hep-ph/0105267
Kirill Melnikov
Kirill Melnikov
On the theoretical uncertainties in the muon anomalous magnetic moment
12 pages, revtex
Int.J.Mod.Phys.A16:4591-4612,2001
10.1142/S0217751X01005602
SLAC-PUB-8844
hep-ph
null
I present a fairly detailed discussion of various contributions to the anomalous magnetic moment of the muon a_mu. I try to give an unbiased evaluation of the validity of the SM prediction for this quantity and to point out some delicate issues involved in its calculation. I conclude that the theory uncertainties in the SM prediction for the muon anomalous magnetic moment are underestimated and a great deal of work will be required to reduce these uncertainties to the level required by experiment.
[ { "created": "Fri, 25 May 2001 17:30:23 GMT", "version": "v1" }, { "created": "Wed, 13 Jun 2001 03:27:24 GMT", "version": "v2" } ]
2008-11-26
[ [ "Melnikov", "Kirill", "" ] ]
I present a fairly detailed discussion of various contributions to the anomalous magnetic moment of the muon a_mu. I try to give an unbiased evaluation of the validity of the SM prediction for this quantity and to point out some delicate issues involved in its calculation. I conclude that the theory uncertainties in the SM prediction for the muon anomalous magnetic moment are underestimated and a great deal of work will be required to reduce these uncertainties to the level required by experiment.
1206.1826
Zhong-Bo Kang
Hongxi Xing, Zhong-Bo Kang, Ivan Vitev, Enke Wang
Transverse momentum imbalance of back-to-back particle production in p+A and e+A collisions
12 pages, 5 figures, all the figures for LHC are updated to p+Pb run at 5 TeV, version in Phys. Rev. D
Phys. Rev. D 86, 094010 (2012)
10.1103/PhysRevD.86.094010
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the nuclear enhancement of the transverse momentum imbalance for back-to-back particle production in both p+A and e+A collisions. Specifically, we present results for photon+jet and photon+hadron production in p+A collisions, di-jet and di-hadron production in e+A collisions, and heavy-quark and heavy-meson pair production in both p+A and e+A collisions. We evaluate the effect of both initial-state and final-state multiple scattering, which determine the strength of the nuclear-induced transverse momentum imbalance in these processes. We give theoretical predictions for the experimentally relevant kinematic regions in d+Au collisions at RHIC, p+Pb collisions at LHC and e+A collisions at the future EIC and LHeC.
[ { "created": "Fri, 8 Jun 2012 17:57:39 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2012 22:09:14 GMT", "version": "v2" } ]
2012-11-12
[ [ "Xing", "Hongxi", "" ], [ "Kang", "Zhong-Bo", "" ], [ "Vitev", "Ivan", "" ], [ "Wang", "Enke", "" ] ]
We study the nuclear enhancement of the transverse momentum imbalance for back-to-back particle production in both p+A and e+A collisions. Specifically, we present results for photon+jet and photon+hadron production in p+A collisions, di-jet and di-hadron production in e+A collisions, and heavy-quark and heavy-meson pair production in both p+A and e+A collisions. We evaluate the effect of both initial-state and final-state multiple scattering, which determine the strength of the nuclear-induced transverse momentum imbalance in these processes. We give theoretical predictions for the experimentally relevant kinematic regions in d+Au collisions at RHIC, p+Pb collisions at LHC and e+A collisions at the future EIC and LHeC.
1512.00098
Silas Beane
Silas R. Beane and Timothy J. Hobbs
Aspects of QCD Current Algebra on a Null Plane
38 pages, 2 figures
null
10.1016/j.aop.2016.05.015
NT@UW-15-15
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Consequences of QCD current algebra formulated on a light-like hyperplane are derived for the forward scattering of vector and axial-vector currents on an arbitrary hadronic target. It is shown that current algebra gives rise to a special class of sum rules that are direct consequences of the independent chiral symmetry that exists at every point on the two-dimensional transverse plane orthogonal to the lightlike direction. These sum rules are obtained by exploiting the closed, infinite-dimensional algebra satisfied by the transverse moments of null-plane axial-vector and vector charge distributions. In the special case of a nucleon target, this procedure leads to the Adler-Weisberger, Gerasimov-Drell-Hearn, Cabbibo-Radicatti and Fubini-Furlan-Rossetti sum rules. Matching to the dispersion-theoretic language which is usually invoked in deriving these sum rules, the moment sum rules are shown to be equivalent to algebraic constraints on forward S-matrix elements in the Regge limit.
[ { "created": "Mon, 30 Nov 2015 23:53:34 GMT", "version": "v1" } ]
2016-07-20
[ [ "Beane", "Silas R.", "" ], [ "Hobbs", "Timothy J.", "" ] ]
Consequences of QCD current algebra formulated on a light-like hyperplane are derived for the forward scattering of vector and axial-vector currents on an arbitrary hadronic target. It is shown that current algebra gives rise to a special class of sum rules that are direct consequences of the independent chiral symmetry that exists at every point on the two-dimensional transverse plane orthogonal to the lightlike direction. These sum rules are obtained by exploiting the closed, infinite-dimensional algebra satisfied by the transverse moments of null-plane axial-vector and vector charge distributions. In the special case of a nucleon target, this procedure leads to the Adler-Weisberger, Gerasimov-Drell-Hearn, Cabbibo-Radicatti and Fubini-Furlan-Rossetti sum rules. Matching to the dispersion-theoretic language which is usually invoked in deriving these sum rules, the moment sum rules are shown to be equivalent to algebraic constraints on forward S-matrix elements in the Regge limit.
hep-ph/0203250
S. V. S. Sastri
S. V. S. Sastry, D. Dutta, A. K. Mohanty and D. K. Srivastava
Evolution of Baryon Rich Quark-Gluon Plasma and radiation of Single Photons
null
null
null
null
hep-ph
null
The (3+1) dimensional expansion of the quark gluon plasma (QGP) produced at finite baryon density has been studied using relativistic hydrodynamical approach. The pressure functional of the equation of state (EoS) has been determined for the interacting nuclear matter with mesons exchange. The EoS has been used to solve hydrodynamical equations using RHLLE algorithm. The space time expansion of the plasma has been studied for the cases of SPS energy and RHIC energy both at finite baryon density and for a hypothetical case of SPS energy at zero baryon density. The space-time evolution is slowed and the life times of QGP and mixed phases are shortened in the presence of finite baryon density. The space time integrated total photon yields have been estimated by convoluting the static emission rates with the space time expansion of the plasma. It has been shown that the total photon yield at zero rapidity is not significantly affected by the baryon density for SPS energy. The total photon yield is unaffected by the Landau-Pomeranchuk-Migdal effect at SPS energy at zero baryon density, as the quark matter contribution to photon yield is less compared to hadronic matter.
[ { "created": "Wed, 27 Mar 2002 06:21:21 GMT", "version": "v1" }, { "created": "Thu, 28 Mar 2002 09:16:37 GMT", "version": "v2" } ]
2009-09-29
[ [ "Sastry", "S. V. S.", "" ], [ "Dutta", "D.", "" ], [ "Mohanty", "A. K.", "" ], [ "Srivastava", "D. K.", "" ] ]
The (3+1) dimensional expansion of the quark gluon plasma (QGP) produced at finite baryon density has been studied using relativistic hydrodynamical approach. The pressure functional of the equation of state (EoS) has been determined for the interacting nuclear matter with mesons exchange. The EoS has been used to solve hydrodynamical equations using RHLLE algorithm. The space time expansion of the plasma has been studied for the cases of SPS energy and RHIC energy both at finite baryon density and for a hypothetical case of SPS energy at zero baryon density. The space-time evolution is slowed and the life times of QGP and mixed phases are shortened in the presence of finite baryon density. The space time integrated total photon yields have been estimated by convoluting the static emission rates with the space time expansion of the plasma. It has been shown that the total photon yield at zero rapidity is not significantly affected by the baryon density for SPS energy. The total photon yield is unaffected by the Landau-Pomeranchuk-Migdal effect at SPS energy at zero baryon density, as the quark matter contribution to photon yield is less compared to hadronic matter.
hep-ph/9510307
Jifang Zhang
Nimai C. Mukhopadhyay, J. -F. Zhang and M. Benmerrouche
Extraction of the Ratio of the N^*(1535) Electromagnetic Helicity Amplitudes from Eta Photoproduction off Neutrons and Protons
4 figures. It will be published in Phys. Lett. B
Phys.Lett.B364:1-7,1995
10.1016/0370-2693(95)01255-X
RPI-95-N104, SAL-TH-95-07
hep-ph nucl-th
null
Using the recent precise measurements of eta photopro- duction in proton and deuteron targets, we extract the ratio of the helicity amplitudes A^n_1/2 / A^p_1/2, for the excitation of N^*(1535), in the effective Lagrangian approach, It is fairly model-independent, free from the final-state interaction effects, and negative as predicted by the quark models. We stress the importance of polarization observables in further elucidation of the N^*(1520) photoexcitation amplitudes.
[ { "created": "Mon, 16 Oct 1995 19:21:05 GMT", "version": "v1" } ]
2016-09-01
[ [ "Mukhopadhyay", "Nimai C.", "" ], [ "Zhang", "J. -F.", "" ], [ "Benmerrouche", "M.", "" ] ]
Using the recent precise measurements of eta photopro- duction in proton and deuteron targets, we extract the ratio of the helicity amplitudes A^n_1/2 / A^p_1/2, for the excitation of N^*(1535), in the effective Lagrangian approach, It is fairly model-independent, free from the final-state interaction effects, and negative as predicted by the quark models. We stress the importance of polarization observables in further elucidation of the N^*(1520) photoexcitation amplitudes.
1309.1721
Bridget Bertoni
Bridget Bertoni, Ann E. Nelson, Sanjay Reddy
Dark Matter Thermalization in Neutron Stars
27 pages, 6 figures. v2: a few comments added, typos fixed--matches published version
Phys. Rev. D. 88, 123505 (2013)
10.1103/PhysRevD.88.123505
INT-PUB-13-038
hep-ph astro-ph.CO nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study how many-body effects alter the dark matter (DM) thermalization time inside neutron stars. We find that Pauli blocking, kinematic constraints, and superfluidity and superconductivity in the neutron star significantly affect the DM thermalization time, in general lengthening it. This could change the final DM mass and DM-nucleon cross section constraints by considering black hole formation in neutron stars due to DM accretion. We consider the class of models in which DM is an asymmetric, complex scalar particle with a mass between 1 keV and 5 GeV which couples to regular matter via some heavy vector boson. Interestingly, we find that the discovery of asymmetric, bosonic DM could motivate the existence of exotic neutron star cores. We apply our results to the case of mixed sneutrino DM.
[ { "created": "Fri, 6 Sep 2013 18:28:52 GMT", "version": "v1" }, { "created": "Wed, 13 Nov 2013 23:36:27 GMT", "version": "v2" } ]
2015-06-17
[ [ "Bertoni", "Bridget", "" ], [ "Nelson", "Ann E.", "" ], [ "Reddy", "Sanjay", "" ] ]
We study how many-body effects alter the dark matter (DM) thermalization time inside neutron stars. We find that Pauli blocking, kinematic constraints, and superfluidity and superconductivity in the neutron star significantly affect the DM thermalization time, in general lengthening it. This could change the final DM mass and DM-nucleon cross section constraints by considering black hole formation in neutron stars due to DM accretion. We consider the class of models in which DM is an asymmetric, complex scalar particle with a mass between 1 keV and 5 GeV which couples to regular matter via some heavy vector boson. Interestingly, we find that the discovery of asymmetric, bosonic DM could motivate the existence of exotic neutron star cores. We apply our results to the case of mixed sneutrino DM.
hep-ph/0108027
Teruya Yamanishi
Yu-Bing Dong, T.Morii, and T.Yamanishi
Extraction of Polarized Gluon Distributions from Large-pt Light Hadron Pair Production
14 pages 3 EPS figures Latex
Phys.Lett. B520 (2001) 99-107
10.1016/S0370-2693(01)01122-4
BIHEP-th-01-01, KOBE-FHD-01-02, FUT-01-01
hep-ph
null
We propose a new formula for extracting the polarized gluon distribution from the large-$p_T$ light hadron pair production for semi-inclusive processes in polarized deep inelastic scattering. In general, a large-$p_T$ hadron pair is produced via photon-gluon fusion(PGF) and QCD Compton at the lowest order of QCD. The PGF gives us a direct information on $\Delta g$ in the nucleon, while QCD Compton becomes background to the signal process for extracting $\Delta g$. We show that the contribution from this background, i.e. the QCD Compton process, can be removed by using symmetry relation among fragmentation functions and taking an appropriate combination of various light hadron pair production processes, and thus the double spin asymmetry can be described in terms of $\Delta g/g$ alone.
[ { "created": "Fri, 3 Aug 2001 04:33:14 GMT", "version": "v1" } ]
2009-11-07
[ [ "Dong", "Yu-Bing", "" ], [ "Morii", "T.", "" ], [ "Yamanishi", "T.", "" ] ]
We propose a new formula for extracting the polarized gluon distribution from the large-$p_T$ light hadron pair production for semi-inclusive processes in polarized deep inelastic scattering. In general, a large-$p_T$ hadron pair is produced via photon-gluon fusion(PGF) and QCD Compton at the lowest order of QCD. The PGF gives us a direct information on $\Delta g$ in the nucleon, while QCD Compton becomes background to the signal process for extracting $\Delta g$. We show that the contribution from this background, i.e. the QCD Compton process, can be removed by using symmetry relation among fragmentation functions and taking an appropriate combination of various light hadron pair production processes, and thus the double spin asymmetry can be described in terms of $\Delta g/g$ alone.
1911.08883
Michael A. Fedderke
Michael A. Fedderke, Peter W. Graham, and Surjeet Rajendran
White Dwarf Bounds on CHAMPs
60 pages, 9 figures. Published version
Phys. Rev. D 101, 115021 (2020)
10.1103/PhysRevD.101.115021
null
hep-ph astro-ph.CO astro-ph.HE astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
White dwarfs (WD) effectively act as high-gain amplifiers for relatively small energy deposits within their volume via their supernova instability. In this paper, we consider the ways a galactic abundance of $\mathcal{O}(1)$-charged massive relics (i.e., CHAMPs) could trigger this instability, thereby destroying old WD. The dense central core structure formed inside the WD when heavy CHAMPs sink to its center can trigger a supernova via injection of energy during collapse phases, via direct density-enhanced (pycnonuclear) fusion processes of carbon nuclei dragged into the core by the CHAMPs, or via the formation of a black hole (BH) at the center of the WD. In the latter scenario, Hawking radiation from the BH can ignite the star if the BH forms with a sufficiently small mass; if the BH instead forms at large enough mass, heating of carbon nuclei that accrete onto the BH as it grows in size may be able to achieve the same outcome (with the conservative alternative being simply that the WD is devoured by the BH). The known existence of old WD that have not been destroyed by these mechanisms allows us to improve by many orders of magnitude on the existing CHAMP abundance constraints in the regime of large CHAMP mass, $m_X \sim 10^{11}$-$10^{18}\,$GeV. Additionally, in certain regions of parameter space, we speculate that this setup could provide a trigger mechanism for the calcium-rich gap transients: a class of anomalous, sub-luminous supernova events that occur far outside of a host galaxy.
[ { "created": "Tue, 19 Nov 2019 04:50:41 GMT", "version": "v1" }, { "created": "Wed, 17 Jun 2020 20:58:18 GMT", "version": "v2" } ]
2020-06-19
[ [ "Fedderke", "Michael A.", "" ], [ "Graham", "Peter W.", "" ], [ "Rajendran", "Surjeet", "" ] ]
White dwarfs (WD) effectively act as high-gain amplifiers for relatively small energy deposits within their volume via their supernova instability. In this paper, we consider the ways a galactic abundance of $\mathcal{O}(1)$-charged massive relics (i.e., CHAMPs) could trigger this instability, thereby destroying old WD. The dense central core structure formed inside the WD when heavy CHAMPs sink to its center can trigger a supernova via injection of energy during collapse phases, via direct density-enhanced (pycnonuclear) fusion processes of carbon nuclei dragged into the core by the CHAMPs, or via the formation of a black hole (BH) at the center of the WD. In the latter scenario, Hawking radiation from the BH can ignite the star if the BH forms with a sufficiently small mass; if the BH instead forms at large enough mass, heating of carbon nuclei that accrete onto the BH as it grows in size may be able to achieve the same outcome (with the conservative alternative being simply that the WD is devoured by the BH). The known existence of old WD that have not been destroyed by these mechanisms allows us to improve by many orders of magnitude on the existing CHAMP abundance constraints in the regime of large CHAMP mass, $m_X \sim 10^{11}$-$10^{18}\,$GeV. Additionally, in certain regions of parameter space, we speculate that this setup could provide a trigger mechanism for the calcium-rich gap transients: a class of anomalous, sub-luminous supernova events that occur far outside of a host galaxy.
1802.03826
Danny Marfatia
Kimberly K. Boddy, Jason Kumar, Danny Marfatia, Pearl Sandick
Model-independent constraints on dark matter annihilation in dwarf spheroidal galaxies
14 pages, 10 figures, 1 table. Typos corrected. The unnormalized background distribution for each dwarf is available in an ancillary file
Phys. Rev. D 97, 095031 (2018)
10.1103/PhysRevD.97.095031
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a general, model-independent formalism for determining bounds on the production of photons in dwarf spheroidal galaxies via dark matter annihilation, applicable to any set of assumptions about dark matter particle physics or astrophysics. As an illustration, we analyze gamma-ray data from the Fermi Large Area Telescope to constrain a variety of nonstandard dark matter models, several of which have not previously been studied in the context of dwarf galaxy searches.
[ { "created": "Sun, 11 Feb 2018 21:56:42 GMT", "version": "v1" }, { "created": "Thu, 24 May 2018 23:26:29 GMT", "version": "v2" } ]
2018-05-28
[ [ "Boddy", "Kimberly K.", "" ], [ "Kumar", "Jason", "" ], [ "Marfatia", "Danny", "" ], [ "Sandick", "Pearl", "" ] ]
We present a general, model-independent formalism for determining bounds on the production of photons in dwarf spheroidal galaxies via dark matter annihilation, applicable to any set of assumptions about dark matter particle physics or astrophysics. As an illustration, we analyze gamma-ray data from the Fermi Large Area Telescope to constrain a variety of nonstandard dark matter models, several of which have not previously been studied in the context of dwarf galaxy searches.
hep-ph/9609453
J. Gunion
J.F. Gunion (U.C. Davis) and X.-G. He (U.C. Davis and Melbourne)
Discriminating between Higgs Boson models using $e^+e^-\to t \anti t \h$ and $Z\h$ at the NLC
5 pages, full postscript file also available via anonymous ftp at ftp://ucdhep.ucdavis.edu/gunion/he_sm96.ps
ECONF C960625:LTH102,1996
null
UCD-96-23
hep-ph hep-ex
null
We demonstrate that the process $e^+e^-\to t\anti t h$ at the NLC provides a powerful tool for extracting the $t\anti t$ (Yukawa) couplings of the $\h$. In combination with the $\epem\to Z\h$ process, an accurate determination of the $ZZ$ coupling of the $\h$ is also possible. The resulting ability to distinguish different models of the Higgs sector is illustrated by detailed studies for two-Higgs-doublet models.
[ { "created": "Tue, 24 Sep 1996 20:14:04 GMT", "version": "v1" } ]
2011-03-02
[ [ "Gunion", "J. F.", "", "U.C. Davis" ], [ "He", "X. -G.", "", "U.C. Davis and Melbourne" ] ]
We demonstrate that the process $e^+e^-\to t\anti t h$ at the NLC provides a powerful tool for extracting the $t\anti t$ (Yukawa) couplings of the $\h$. In combination with the $\epem\to Z\h$ process, an accurate determination of the $ZZ$ coupling of the $\h$ is also possible. The resulting ability to distinguish different models of the Higgs sector is illustrated by detailed studies for two-Higgs-doublet models.
0804.4330
William Horowitz
W. A. Horowitz and M. Gyulassy
Testing AdS/CFT Drag and pQCD Heavy Quark Energy Loss
4 pages, 4 figures. Presented at the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions: Quark Matter 2008 (QM2008), Jaipur, India, 4-10 Feb 2008
J.Phys.G35:104152,2008
10.1088/0954-3899/35/10/104152
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present charm and bottom nuclear modification factors for RHIC and LHC using Standard Model perturbative QCD and recent AdS/CFT string drag energy loss models. We find that extreme extrapolations to LHC mask potential experimentally determinable differences in the individual $R_{AA}$s but that their ratio, $R_{AA}^c/R_{AA}^b$ as a function of transverse momentum is a remarkably robust observable for finding deviations from either theoretical framework.
[ { "created": "Mon, 28 Apr 2008 06:54:04 GMT", "version": "v1" } ]
2008-11-26
[ [ "Horowitz", "W. A.", "" ], [ "Gyulassy", "M.", "" ] ]
We present charm and bottom nuclear modification factors for RHIC and LHC using Standard Model perturbative QCD and recent AdS/CFT string drag energy loss models. We find that extreme extrapolations to LHC mask potential experimentally determinable differences in the individual $R_{AA}$s but that their ratio, $R_{AA}^c/R_{AA}^b$ as a function of transverse momentum is a remarkably robust observable for finding deviations from either theoretical framework.
1104.3512
Matthias Aicher
Matthias Aicher, Andreas Sch\"afer, Werner Vogelsang
Threshold-Resummed Cross Section for the Drell-Yan Process in Pion-Nucleon Collisions at COMPASS
8 pages, 7 figures
Phys.Rev.D83:114023,2011
10.1103/PhysRevD.83.114023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a study of the Drell-Yan process in pion-proton collisions including next-to-leading-logarithmic threshold-resummed contributions. We analyze rapidity-integrated as well as rapidity-differential cross sections in the kinematic regime relevant for the COMPASS fixed target experiment. We find that resummation leads to a significant enhancement of the cross section compared to fixed-order calculations in this regime. Particularly large corrections arise at large forward and backward rapidities of the lepton pair. We also study the scale dependence of the cross section and find it to be substantially reduced by threshold resummation.
[ { "created": "Mon, 18 Apr 2011 15:17:38 GMT", "version": "v1" } ]
2011-06-24
[ [ "Aicher", "Matthias", "" ], [ "Schäfer", "Andreas", "" ], [ "Vogelsang", "Werner", "" ] ]
We present a study of the Drell-Yan process in pion-proton collisions including next-to-leading-logarithmic threshold-resummed contributions. We analyze rapidity-integrated as well as rapidity-differential cross sections in the kinematic regime relevant for the COMPASS fixed target experiment. We find that resummation leads to a significant enhancement of the cross section compared to fixed-order calculations in this regime. Particularly large corrections arise at large forward and backward rapidities of the lepton pair. We also study the scale dependence of the cross section and find it to be substantially reduced by threshold resummation.
1912.00899
Natascia Vignaroli
Natascia Vignaroli
Leptoquarks in B-meson anomalies: simplified models and HL-LHC discovery prospects
Presented at IFAE 2019, 8-10 April, Naples, Italy
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I will review simplified models with leptoquarks, which can explain recent anomalies in $B$-meson physics, and I will indicate the High-Luminosity LHC prospects for testing these theories, with a special focus to the efficient channel of pair leptoquark production in the $t\bar t$ plus missing energy final state.
[ { "created": "Mon, 2 Dec 2019 16:25:09 GMT", "version": "v1" }, { "created": "Mon, 23 Dec 2019 11:46:10 GMT", "version": "v2" } ]
2019-12-24
[ [ "Vignaroli", "Natascia", "" ] ]
I will review simplified models with leptoquarks, which can explain recent anomalies in $B$-meson physics, and I will indicate the High-Luminosity LHC prospects for testing these theories, with a special focus to the efficient channel of pair leptoquark production in the $t\bar t$ plus missing energy final state.
1907.08794
Krzysztof Marek Kutak
Krzysztof Kutak
ITMD factorization and broadening effects in production of forward di-jets
6 pages, proceedings of DIS 2019, Torino
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I report on the recent result of comparison of forward-forward dijet correlations in azimuthal angle as measured by the ATLAS collaboration in the proton-proton and proton-lead collisions to calculations within ITMD factorization framework [1]. The comparison shows that the broadening effect due to interplay of both the gluon saturation and the Sudakov resummation is necessary to describe the data.
[ { "created": "Sat, 20 Jul 2019 10:53:06 GMT", "version": "v1" } ]
2019-07-23
[ [ "Kutak", "Krzysztof", "" ] ]
I report on the recent result of comparison of forward-forward dijet correlations in azimuthal angle as measured by the ATLAS collaboration in the proton-proton and proton-lead collisions to calculations within ITMD factorization framework [1]. The comparison shows that the broadening effect due to interplay of both the gluon saturation and the Sudakov resummation is necessary to describe the data.
1212.2730
Yue Zhang
Yue Zhang
Top Quark Mediated Dark Matter
6 pages, 4 figures; accepted for publication in Physics Letters B
null
10.1016/j.physletb.2013.01.063
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the top quark portal dominated dark matter interactions, and its implications for the gamma ray line searches. In this picture, the dark matter interactions with photons and gluons are loop induced by the axial anomaly of the top quark current. We show there can be a natural suppression of the tree-level annihilation of dark matter, and the photon channel in turn has a substantial rate when the main annihilation proceeds into gluons. We observe a competition between the indirect detection of gamma ray line and the search with monojet plus missing energy events at LHC, and the 7 TeV data already set an upper bound of ~ 10^{-28} cm^3/s on the photonic annihilation cross section. This upper limit is compatible with a thermal WIMP scenario.
[ { "created": "Wed, 12 Dec 2012 08:38:00 GMT", "version": "v1" }, { "created": "Thu, 31 Jan 2013 14:29:43 GMT", "version": "v2" } ]
2015-06-12
[ [ "Zhang", "Yue", "" ] ]
We study the top quark portal dominated dark matter interactions, and its implications for the gamma ray line searches. In this picture, the dark matter interactions with photons and gluons are loop induced by the axial anomaly of the top quark current. We show there can be a natural suppression of the tree-level annihilation of dark matter, and the photon channel in turn has a substantial rate when the main annihilation proceeds into gluons. We observe a competition between the indirect detection of gamma ray line and the search with monojet plus missing energy events at LHC, and the 7 TeV data already set an upper bound of ~ 10^{-28} cm^3/s on the photonic annihilation cross section. This upper limit is compatible with a thermal WIMP scenario.
hep-ph/0001211
Eduard Volodymyrouych Gorbar
E. V. Gorbar (Instituto de Fisica Teorica, Sao Paulo, Brazil)
On Color Superconductivity in External Magnetic Field
12 pages, LaTeX
Phys.Rev. D62 (2000) 014007
10.1103/PhysRevD.62.014007
null
hep-ph
null
We study color superconductivity in external magnetic field. We discuss the reason why the mixing angles in color-flavor locked (CFL) and two-flavor superconductivity (2SC) phases are different despite the fact that the CFL gap goes to the 2SC gap for $m_s \to \infty$. Although flavor symmetry is explicitly broken in external magnetic field, we show that all values of gaps in their coset spaces of possible solutions in the CFL phase are equivalent in external magnetic field.
[ { "created": "Thu, 20 Jan 2000 12:55:56 GMT", "version": "v1" } ]
2009-10-31
[ [ "Gorbar", "E. V.", "", "Instituto de Fisica Teorica, Sao Paulo, Brazil" ] ]
We study color superconductivity in external magnetic field. We discuss the reason why the mixing angles in color-flavor locked (CFL) and two-flavor superconductivity (2SC) phases are different despite the fact that the CFL gap goes to the 2SC gap for $m_s \to \infty$. Although flavor symmetry is explicitly broken in external magnetic field, we show that all values of gaps in their coset spaces of possible solutions in the CFL phase are equivalent in external magnetic field.
1405.3154
Kenji Fukushima
Ryoji Anzaki, Kenji Fukushima, Yoshimasa Hidaka, Takashi Oka
Restricted phase-space approximation in real-time stochastic quantization
35 pages, 10 figures; typos corrected, irrelevant numerical tests deleted, confusing explanations elaborated, sections sorted out well; main results not changed
Annals of Phys. 353, 107-208 (2015)
10.1016/j.aop.2014.11.004
RIKEN-QHP-150
hep-ph cond-mat.str-el hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform and extend real-time numerical simulation of a low-dimensional scalar field theory or a quantum mechanical system using stochastic quantization. After a brief review of the quantization method and the complex Langevin dynamics, we calculate the propagator and make a comparison with analytical results. This is a first step toward general applications, and we focus only on the vacuum properties of the theory; this enables us to handle the boundary condition with the $i\epsilon$ prescription in frequency space. While we can control stability of the numerical simulation for any coupling strength, our results turn out to flow into an unphysical fixed-point, which is qualitatively understood from the corresponding Fokker-Planck equation. We propose a simple truncation scheme, "restricted phase-space approximation," to avoid the unphysical fixed-point. With this method, we obtain stable results at reasonably good accuracy. Finally we give a short discussion on the closed-time path formalism and demonstrate the direct computation of the vacuum expectation value not with the $i\epsilon$ prescription but from an explicit construction of the Feynman kernel.
[ { "created": "Tue, 13 May 2014 13:59:26 GMT", "version": "v1" }, { "created": "Sun, 19 Oct 2014 00:50:02 GMT", "version": "v2" } ]
2015-01-30
[ [ "Anzaki", "Ryoji", "" ], [ "Fukushima", "Kenji", "" ], [ "Hidaka", "Yoshimasa", "" ], [ "Oka", "Takashi", "" ] ]
We perform and extend real-time numerical simulation of a low-dimensional scalar field theory or a quantum mechanical system using stochastic quantization. After a brief review of the quantization method and the complex Langevin dynamics, we calculate the propagator and make a comparison with analytical results. This is a first step toward general applications, and we focus only on the vacuum properties of the theory; this enables us to handle the boundary condition with the $i\epsilon$ prescription in frequency space. While we can control stability of the numerical simulation for any coupling strength, our results turn out to flow into an unphysical fixed-point, which is qualitatively understood from the corresponding Fokker-Planck equation. We propose a simple truncation scheme, "restricted phase-space approximation," to avoid the unphysical fixed-point. With this method, we obtain stable results at reasonably good accuracy. Finally we give a short discussion on the closed-time path formalism and demonstrate the direct computation of the vacuum expectation value not with the $i\epsilon$ prescription but from an explicit construction of the Feynman kernel.