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1304.0790
Benjamin Fuks
Benjamin Fuks, Michael Klasen, David R. Lamprea, Marcel Rothering
Precision predictions for electroweak superpartner production at hadron colliders with Resummino
9 pages, 1 figure, 1 table; version accepted by EPJC; program to be downloaded from http://www.resummino.org
Eur. Phys. J. C73 (2013) 2480
10.1140/epjc/s10052-013-2480-0
CERN-PH-TH/2013-064, IPHC-PHENO-13-02, MS-TP-13-06
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the Resummino package, a C++ and Fortran program dedicated to precision calculations in the framework of gaugino and slepton pair production at hadron colliders. This code allows to calculate transverse-momentum and invariant-mass distributions as well as total cross sections by combining the next-to-leading order predictions obtained by means of perturbative QCD with the resummation of the large logarithmic contributions arising in the small transverse-momentum region and close to the production threshold. The results computed in this way benefit from reduced theoretical uncertainties, compared to a pure next-to-leading order approach as currently employed in the experimental analyses searching for sleptons and gauginos at hadron colliders. This is illustrated by using of Resummino in the context of a typical supersymmetric benchmark point dedicated to superpartner searches at the Large Hadron Collider.
[ { "created": "Tue, 2 Apr 2013 20:30:23 GMT", "version": "v1" }, { "created": "Fri, 14 Jun 2013 12:29:47 GMT", "version": "v2" } ]
2013-07-09
[ [ "Fuks", "Benjamin", "" ], [ "Klasen", "Michael", "" ], [ "Lamprea", "David R.", "" ], [ "Rothering", "Marcel", "" ] ]
We describe the Resummino package, a C++ and Fortran program dedicated to precision calculations in the framework of gaugino and slepton pair production at hadron colliders. This code allows to calculate transverse-momentum and invariant-mass distributions as well as total cross sections by combining the next-to-leading order predictions obtained by means of perturbative QCD with the resummation of the large logarithmic contributions arising in the small transverse-momentum region and close to the production threshold. The results computed in this way benefit from reduced theoretical uncertainties, compared to a pure next-to-leading order approach as currently employed in the experimental analyses searching for sleptons and gauginos at hadron colliders. This is illustrated by using of Resummino in the context of a typical supersymmetric benchmark point dedicated to superpartner searches at the Large Hadron Collider.
1908.00423
Han Zhou
Tianjun Li, Qian-Fei Xiang, Qi-Shu Yan, Xianhui Zhang, Han Zhou
Isospin-Violating Dark Matter in the $U(1)'$ Model with $E_6$ Origin
16 pages, 4 figures
Phys. Rev. D 101, 035016 (2020)
10.1103/PhysRevD.101.035016
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose a $U(1)'$ model from $E_6$ which has an isospin-violation dark matter. By choosing a proper linear combination of two extra $U(1)$ gauge symmetries in $E_6$, it is natural to realize the ratio $f_n/f_p=-0.7$ so as to maximally relax the constraints from the Xenon based direct detection experiments. We study the sensitivities of the dark matter direct and indirect detection experiments, and identify the parameter spaces that can give the observed relic density. We also study the sensitivities of the future colliders with center mass energy $\sqrt{s}$= 33/50/100 TeV, and compare the different detection methods. We show that in some parameter spaces the future colliders can give much stronger limits.
[ { "created": "Thu, 1 Aug 2019 14:15:51 GMT", "version": "v1" }, { "created": "Fri, 14 Feb 2020 02:49:27 GMT", "version": "v2" } ]
2020-02-19
[ [ "Li", "Tianjun", "" ], [ "Xiang", "Qian-Fei", "" ], [ "Yan", "Qi-Shu", "" ], [ "Zhang", "Xianhui", "" ], [ "Zhou", "Han", "" ] ]
We propose a $U(1)'$ model from $E_6$ which has an isospin-violation dark matter. By choosing a proper linear combination of two extra $U(1)$ gauge symmetries in $E_6$, it is natural to realize the ratio $f_n/f_p=-0.7$ so as to maximally relax the constraints from the Xenon based direct detection experiments. We study the sensitivities of the dark matter direct and indirect detection experiments, and identify the parameter spaces that can give the observed relic density. We also study the sensitivities of the future colliders with center mass energy $\sqrt{s}$= 33/50/100 TeV, and compare the different detection methods. We show that in some parameter spaces the future colliders can give much stronger limits.
hep-ph/9810467
James Pantaleone
J. Pantaleone
Getting the Most From Atmospheric Neutrinos
13 pages, 2 figures To be published in Physical Review Letters
Phys.Rev.Lett. 81 (1998) 5060-5063
10.1103/PhysRevLett.81.5060
null
hep-ph
null
Observations of atmospheric neutrinos by the SuperKamiokande collaboration have demonstrated large mixing of the muon-neutrino. However the present atmospheric neutrino data does not significantly constrain the associated mixing of the electron-neutrino, or the sign of the mass-squared difference. Here we identify the diagnostics for these quantities and they also test the theory of how matter affects neutrino oscillations. These diagnostics are a dip in the sub-GeV muon flux at a zenith angle of 110 degrees, a bump in the electron up-down asymmetry at multi-GeV energies and a bump in the muon-antimuon upward asymmetry.
[ { "created": "Fri, 23 Oct 1998 23:36:07 GMT", "version": "v1" } ]
2009-10-31
[ [ "Pantaleone", "J.", "" ] ]
Observations of atmospheric neutrinos by the SuperKamiokande collaboration have demonstrated large mixing of the muon-neutrino. However the present atmospheric neutrino data does not significantly constrain the associated mixing of the electron-neutrino, or the sign of the mass-squared difference. Here we identify the diagnostics for these quantities and they also test the theory of how matter affects neutrino oscillations. These diagnostics are a dip in the sub-GeV muon flux at a zenith angle of 110 degrees, a bump in the electron up-down asymmetry at multi-GeV energies and a bump in the muon-antimuon upward asymmetry.
hep-ph/0409360
John Ellis
John Ellis
Summary of ICHEP 2004
19 pages LaTeX, 12 eps figures, Summary of the International Conference on High-Energy Physics, Beijing, China, August 2004
Int.J.Mod.Phys.A20:5297-5315,2005
10.1142/S0217751X05028806
CERN-PH-TH/2004-167
hep-ph
null
Aspects of ICHEP 2004 are summarized from a theoretical point of view. QCD works, new NNLO calculations are becoming available and new string calculational tools are emerging, but no conclusions can yet be drawn about the discovery of the quark-gluon plasma or pentaquarks. The small upward shift in the experimental value of m_t raises somewhat the central value of the Higgs mass extracted from a global electroweak fit, and the CKM model describes well the data from the B factories. The Super-Kamiokande, KamLAND and K2K experiments have evidence for oscillation dips in their neutrino data. Little Higgs models are interesting alternatives to low-energy supersymmetry for stabilizing the electroweak scale. Convincing experimental evidence for dark matter particles is still lacking. The LHC is on its way, the technology choice clarifies the roadmap for the ILC, and a multi-TeV CLIC would also have rich physics agenda.
[ { "created": "Thu, 30 Sep 2004 16:38:42 GMT", "version": "v1" } ]
2010-11-05
[ [ "Ellis", "John", "" ] ]
Aspects of ICHEP 2004 are summarized from a theoretical point of view. QCD works, new NNLO calculations are becoming available and new string calculational tools are emerging, but no conclusions can yet be drawn about the discovery of the quark-gluon plasma or pentaquarks. The small upward shift in the experimental value of m_t raises somewhat the central value of the Higgs mass extracted from a global electroweak fit, and the CKM model describes well the data from the B factories. The Super-Kamiokande, KamLAND and K2K experiments have evidence for oscillation dips in their neutrino data. Little Higgs models are interesting alternatives to low-energy supersymmetry for stabilizing the electroweak scale. Convincing experimental evidence for dark matter particles is still lacking. The LHC is on its way, the technology choice clarifies the roadmap for the ILC, and a multi-TeV CLIC would also have rich physics agenda.
hep-ph/0306257
Hans Volker Klapdor-Kleingrothaus
C. Tomei (Universit`a degli Studi de L'Aquila, Italy), A. Dietz (MPI-Kernphysik, Heidelberg, Germany), I. Krivosheina (MPI-Kernphysik, Heidelberg, Germany and NIRFI, Nignij-Novgorod, Russia) and H.V. Klapdor-Kleingrothaus (MPI-Kernphysik, Heidelberg, Germany)
Searching for the Annual Modulation of Dark Matter signal with the GENIUS-TF experiment
In press, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2003) and in Proc. of IDM2002, York Minster, England, 2-6 September, 2002, World Scientific 2003
Nucl.Instrum.Meth. A508 (2003) 343-352
10.1016/S0168-9002(03)01511-0
null
hep-ph
null
The annual modulation of the recoil spectrum observed in an underground detector is well known as the main signature of a possible WIMP signal. The GENIUS-TF experiment, under construction in the Gran Sasso National Laboratory, can search for the annual modulation of the Dark Matter signal using 40 kg of naked-Ge detectors in liquid nitrogen. Starting from a set of data simulated under the hypothesis of modulation and using different methods, we show the potential of GENIUS-TF for extracting the modulated signal and the expected WIMP mass and WIMP cross section.
[ { "created": "Thu, 26 Jun 2003 09:26:25 GMT", "version": "v1" } ]
2009-11-10
[ [ "Tomei", "C.", "", "Universit`a degli Studi de L'Aquila, Italy" ], [ "Dietz", "A.", "", "MPI-Kernphysik, Heidelberg, Germany" ], [ "Krivosheina", "I.", "", "MPI-Kernphysik,\n Heidelberg, Germany and NIRFI, Nignij-Novgorod, Russia" ], [ "Klapdor-Klei...
The annual modulation of the recoil spectrum observed in an underground detector is well known as the main signature of a possible WIMP signal. The GENIUS-TF experiment, under construction in the Gran Sasso National Laboratory, can search for the annual modulation of the Dark Matter signal using 40 kg of naked-Ge detectors in liquid nitrogen. Starting from a set of data simulated under the hypothesis of modulation and using different methods, we show the potential of GENIUS-TF for extracting the modulated signal and the expected WIMP mass and WIMP cross section.
hep-ph/0211396
Xiao-Gang He
Xiao-Gang He (NTU)
Higgs Mass from Casimir Energy Induced Cosmological Constant in the Standard Model
RevTex 9 pages, no figure, several comments and references added
Mod.Phys.Lett. A19 (2004) 1195-1202
10.1142/S0217732304014550
null
hep-ph astro-ph hep-ex hep-th
null
Casimir vacuum energy is divergent. It needs to be regularized. The regularization introduces a renormalization scale which may lead to a scale dependent cosmological constant. We show that the requirement of physical cosmological constant is renormalization scale independent provides important constraints on possible particle contents and their masses in particle physics models. In the Standard Model of strong and electroweak interactions, besides the Casimir vacuum energy there is also vacuum energy induced from spontaneous symmetry breaking. The requirement that the total vacuum energy to be scale independent dictates the Higgs mass to be $m_H^4 = 8\sum_i N_i m^4_i - 12m^4_W - 6 m^4_Z$, where the summation is over fermions and $N_i$ equals to 3 and 1 for quarks and leptons, respectively. The Higgs mass is predicted to be approximately 382 GeV.
[ { "created": "Mon, 25 Nov 2002 23:26:26 GMT", "version": "v1" }, { "created": "Mon, 2 Dec 2002 01:33:01 GMT", "version": "v2" } ]
2009-11-07
[ [ "He", "Xiao-Gang", "", "NTU" ] ]
Casimir vacuum energy is divergent. It needs to be regularized. The regularization introduces a renormalization scale which may lead to a scale dependent cosmological constant. We show that the requirement of physical cosmological constant is renormalization scale independent provides important constraints on possible particle contents and their masses in particle physics models. In the Standard Model of strong and electroweak interactions, besides the Casimir vacuum energy there is also vacuum energy induced from spontaneous symmetry breaking. The requirement that the total vacuum energy to be scale independent dictates the Higgs mass to be $m_H^4 = 8\sum_i N_i m^4_i - 12m^4_W - 6 m^4_Z$, where the summation is over fermions and $N_i$ equals to 3 and 1 for quarks and leptons, respectively. The Higgs mass is predicted to be approximately 382 GeV.
1805.00935
Scientific Information Service CERN
Martijn Mulders, Giulia Zanderighi (CERN)
The 2016 European School of High-Energy Physics
7 lectures, 312 pages, published as CERN Yellow Report a this url: https://e-publishing.cern.ch/index.php/CYRSP/issue/view/45
null
10.23730/CYRSP-2017-005
CERN-2017-009-SP
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The European School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lecture notes on the theory of the Weak interaction and Higgs physics, flavour physics and CP violation, neutrinos, theories beyond the Standard Model, physics at the LHC Run-2 and beyond, practical statistics for high-energy physicists, and cosmology and dark matter.
[ { "created": "Wed, 2 May 2018 08:34:58 GMT", "version": "v1" } ]
2018-05-04
[ [ "Mulders", "Martijn", "", "CERN" ], [ "Zanderighi", "Giulia", "", "CERN" ] ]
The European School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lecture notes on the theory of the Weak interaction and Higgs physics, flavour physics and CP violation, neutrinos, theories beyond the Standard Model, physics at the LHC Run-2 and beyond, practical statistics for high-energy physicists, and cosmology and dark matter.
1301.3965
Raymond R. Volkas
Raymond R. Volkas
Unified origin for visible and dark matter in a baryon-symmetric universe from a first-order phase transition
5 pages. Invited talk at CosPA 2012 Symposium, Nov. 13-17, Taiwan. Submitted to the proceedings. v2: added references
null
10.1016/j.nuclphysbps.2013.10.065
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a baryon-symmetric universe, the baryon asymmetry observed for visible matter is matched by an equal and opposite asymmetry for dark matter, thereby closely connecting the number densities of both types of matter. This is a necessary step towards the goal of explaining the mystery of why the visible and dark matter densities are observed to be similar. In this talk, a way of producing such a universe from bubble nucleation during a first-order phase transition is reviewed. The process is an analog of electroweak baryogenesis.
[ { "created": "Thu, 17 Jan 2013 02:13:11 GMT", "version": "v1" }, { "created": "Thu, 24 Jan 2013 03:57:25 GMT", "version": "v2" } ]
2015-06-12
[ [ "Volkas", "Raymond R.", "" ] ]
In a baryon-symmetric universe, the baryon asymmetry observed for visible matter is matched by an equal and opposite asymmetry for dark matter, thereby closely connecting the number densities of both types of matter. This is a necessary step towards the goal of explaining the mystery of why the visible and dark matter densities are observed to be similar. In this talk, a way of producing such a universe from bubble nucleation during a first-order phase transition is reviewed. The process is an analog of electroweak baryogenesis.
0707.4276
Hannes Jung
Magnus Hansson (Lund University), Hannes Jung (DESY)
Towards precision determination of uPDFs
Contribution to DIS07, Munich, 2007
null
null
null
hep-ph
null
The unintegrated Parton Density Function of the gluon is obtained from a fit to dijet production in DIS as measured at HERA. Reasonable descriptions of the measurements are obtained, and a first attempt to constrain the intrinsic transverse momentum distribution at small kt is presented
[ { "created": "Sun, 29 Jul 2007 07:36:52 GMT", "version": "v1" } ]
2007-07-31
[ [ "Hansson", "Magnus", "", "Lund University" ], [ "Jung", "Hannes", "", "DESY" ] ]
The unintegrated Parton Density Function of the gluon is obtained from a fit to dijet production in DIS as measured at HERA. Reasonable descriptions of the measurements are obtained, and a first attempt to constrain the intrinsic transverse momentum distribution at small kt is presented
2009.12347
Bingrong Yu
Bingrong Yu, Shun Zhou
Sufficient and Necessary Conditions for CP Conservation in the Case of Degenerate Majorana Neutrino Masses
28 pages, 2 tables, more discussions and references added, accepted for publication in Phys. Rev. D
Phys. Rev. D 103, 035017 (2021)
10.1103/PhysRevD.103.035017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we carry out a systematic study of the sufficient and necessary conditions for CP conservation in the leptonic sector with massive Majorana neutrinos. In particular, the emphasis is placed on the number of CP-violating phases in the presence of a partial mass degeneracy (e.g., $m^{}_1 = m^{}_2 \neq m^{}_3$) or a complete mass degeneracy $m^{}_1 = m^{}_2 = m^{}_3$, where $m^{}_i$ (for $i = 1, 2, 3$) stand for the masses of three ordinary neutrinos. In the canonical seesaw model with three right-handed neutrino singlets, CP-violating phases in the special case of a partial (e.g., $M^{}_1 = M^{}_2 \neq M^{}_3$) or complete (i.e., $M^{}_1 = M^{}_2 = M^{}_3$) mass degeneracy of three heavy Majorana neutrinos are also examined. In addition, we derive the renormalization-group equations of the weak-basis invariants in the effective theory with a general mass spectrum of Majorana neutrinos, to which the solutions establish the direct connection between CP violation at low- and high-energy scales.
[ { "created": "Fri, 25 Sep 2020 17:14:57 GMT", "version": "v1" }, { "created": "Thu, 1 Oct 2020 10:15:07 GMT", "version": "v2" }, { "created": "Thu, 14 Jan 2021 07:25:18 GMT", "version": "v3" } ]
2021-02-23
[ [ "Yu", "Bingrong", "" ], [ "Zhou", "Shun", "" ] ]
In this paper, we carry out a systematic study of the sufficient and necessary conditions for CP conservation in the leptonic sector with massive Majorana neutrinos. In particular, the emphasis is placed on the number of CP-violating phases in the presence of a partial mass degeneracy (e.g., $m^{}_1 = m^{}_2 \neq m^{}_3$) or a complete mass degeneracy $m^{}_1 = m^{}_2 = m^{}_3$, where $m^{}_i$ (for $i = 1, 2, 3$) stand for the masses of three ordinary neutrinos. In the canonical seesaw model with three right-handed neutrino singlets, CP-violating phases in the special case of a partial (e.g., $M^{}_1 = M^{}_2 \neq M^{}_3$) or complete (i.e., $M^{}_1 = M^{}_2 = M^{}_3$) mass degeneracy of three heavy Majorana neutrinos are also examined. In addition, we derive the renormalization-group equations of the weak-basis invariants in the effective theory with a general mass spectrum of Majorana neutrinos, to which the solutions establish the direct connection between CP violation at low- and high-energy scales.
1202.2711
Grzegorz Wilk
Grzegorz Wilk and Zbigniew Wlodarczyk
Correlations from generalized thermodynamics
Presented at The Seventh Workshop on Particle Correlations and Femtoscopy, September 20 - 24 2011, University of Tokyo, Japan. Final, corrected, version
PoS (WPCF2011) 041
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to account for possible nonstatistical fluctuations in a hadronizing system (leading to the characteristic power-like behavior of the respective single particle spectra and to the broadening of the corresponding multiparticle distributions) while using the statistical approach one has to resort to its nonextensive version. The new parameter q appearing there is directly connected to the variance of the particular variable X, q = 1+Var(X)/<X>^2 (with q = 1 for the usual statistical model). We shall demonstrate here how such an approach allows us to compose fluctuations of different observables (described by their respective parameters q) leading to a characteristic sum rule connecting q's deduced from measurements of these observables, which can be verified experimentally. We shall also discuss ensembles in which all relevant quantities, namely the energy (U), temperature (T) and multiplicity (N), can fluctuate. A specific relation connecting all these fluctuating variables is proposed. It generalizes the so called Lindhard thermodynamic uncertainty relations known in the literature, by introducing, in a natural way, a possibility of correlations between the fluctuating variables considered. This point is illustrated using an example from the multiparticle production processes. We show that fluctuations from different parts of phase space (characterized by different parameters q) are correlated and that the strength of these correlations is a function of these q's, Cov(U,T) = F({q}). These correlations can be tested experimentally. Some rough first estimates, using available data, are presented.
[ { "created": "Mon, 13 Feb 2012 12:45:45 GMT", "version": "v1" }, { "created": "Mon, 20 Feb 2012 15:03:16 GMT", "version": "v2" } ]
2012-02-21
[ [ "Wilk", "Grzegorz", "" ], [ "Wlodarczyk", "Zbigniew", "" ] ]
In order to account for possible nonstatistical fluctuations in a hadronizing system (leading to the characteristic power-like behavior of the respective single particle spectra and to the broadening of the corresponding multiparticle distributions) while using the statistical approach one has to resort to its nonextensive version. The new parameter q appearing there is directly connected to the variance of the particular variable X, q = 1+Var(X)/<X>^2 (with q = 1 for the usual statistical model). We shall demonstrate here how such an approach allows us to compose fluctuations of different observables (described by their respective parameters q) leading to a characteristic sum rule connecting q's deduced from measurements of these observables, which can be verified experimentally. We shall also discuss ensembles in which all relevant quantities, namely the energy (U), temperature (T) and multiplicity (N), can fluctuate. A specific relation connecting all these fluctuating variables is proposed. It generalizes the so called Lindhard thermodynamic uncertainty relations known in the literature, by introducing, in a natural way, a possibility of correlations between the fluctuating variables considered. This point is illustrated using an example from the multiparticle production processes. We show that fluctuations from different parts of phase space (characterized by different parameters q) are correlated and that the strength of these correlations is a function of these q's, Cov(U,T) = F({q}). These correlations can be tested experimentally. Some rough first estimates, using available data, are presented.
hep-ph/0102250
Bing An Li
Bing An Li (Univ. of Kentucky)
Form factor of \pi^0-->\gamma\gamma^*
13 pages and 1 figure
null
null
null
hep-ph
null
An intrinsic form factor has benn found and the slope of the form factor has been predicted.
[ { "created": "Tue, 20 Feb 2001 14:36:20 GMT", "version": "v1" } ]
2007-05-23
[ [ "Li", "Bing An", "", "Univ. of Kentucky" ] ]
An intrinsic form factor has benn found and the slope of the form factor has been predicted.
2008.05450
Pablo Candia da Silva
Pablo Candia da Silva and Apostolos Pilaftsis
Radiative Neutrino Masses in the $\nu_R$MSSM
24 pages, minor modifications
Phys. Rev. D 102, 095013 (2020)
10.1103/PhysRevD.102.095013
MAN/HEP/2020/07
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a complete analysis of scenarios with radiatively generated neutrino masses that may occur in the Minimal Supersymmetric Standard Model with low-scale right-handed neutrinos. For brevity, we call such a model the $\nu_R$MSSM. We pay particular attention to the impact of the non-renormalization theorem of supersymmetry (SUSY) on the loop-induced neutrino masses, by performing our computations in the weak and flavour bases. In particular, we find that the smallness of the observed light neutrino masses may naturally arise due to a soft SUSY-screening effect from a nearly supersymmetric singlet neutrino sector. The profound phenomenological and cosmological implications that may originate from this screening phenomenon in the $\nu_R$MSSM and its minimal extensions are discussed.
[ { "created": "Wed, 12 Aug 2020 17:27:52 GMT", "version": "v1" }, { "created": "Fri, 4 Sep 2020 20:03:10 GMT", "version": "v2" }, { "created": "Fri, 9 Oct 2020 10:52:52 GMT", "version": "v3" } ]
2020-11-18
[ [ "da Silva", "Pablo Candia", "" ], [ "Pilaftsis", "Apostolos", "" ] ]
We present a complete analysis of scenarios with radiatively generated neutrino masses that may occur in the Minimal Supersymmetric Standard Model with low-scale right-handed neutrinos. For brevity, we call such a model the $\nu_R$MSSM. We pay particular attention to the impact of the non-renormalization theorem of supersymmetry (SUSY) on the loop-induced neutrino masses, by performing our computations in the weak and flavour bases. In particular, we find that the smallness of the observed light neutrino masses may naturally arise due to a soft SUSY-screening effect from a nearly supersymmetric singlet neutrino sector. The profound phenomenological and cosmological implications that may originate from this screening phenomenon in the $\nu_R$MSSM and its minimal extensions are discussed.
hep-ph/0111457
Ismd31
Bai YuTing, Fu JingHua and Wu YuanFang
Event-by-Event Fluctuations of Transverse Momentum in Elementary Collisions at 250 GeV/$c$
4 pages, 5 figure (in epsi) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn/
null
null
null
hep-ph
null
We present a study of event-by-event fluctuations of transverse momentum in $\pi^{+}\p$ and $\K^{+}\p$ collisions at 250 GeV/$c$ and the corresponding PYTHIA Monte Carlo results for $\pi^{+}\p$ collisions. The dependence of $\Phi_{p_{t}}$ on event and particle variables are investigated in detail. We find that $\Phi_{p_t}$ are all negative for different average transverse momentum per event sample. The $<p_{t} >_N \sim N$ correlation may not be the only origin of $\Phi_{p_{t}}$.
[ { "created": "Fri, 30 Nov 2001 10:56:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "YuTing", "Bai", "" ], [ "JingHua", "Fu", "" ], [ "YuanFang", "Wu", "" ] ]
We present a study of event-by-event fluctuations of transverse momentum in $\pi^{+}\p$ and $\K^{+}\p$ collisions at 250 GeV/$c$ and the corresponding PYTHIA Monte Carlo results for $\pi^{+}\p$ collisions. The dependence of $\Phi_{p_{t}}$ on event and particle variables are investigated in detail. We find that $\Phi_{p_t}$ are all negative for different average transverse momentum per event sample. The $<p_{t} >_N \sim N$ correlation may not be the only origin of $\Phi_{p_{t}}$.
hep-ph/0306033
Fu-Guang Cao
Fu-Guang Cao and A. I. Signal (Massey University, New Zealand)
Non-perturbative structure of the polarized nucleon sea
RevTex, 17 pages plus 8 PS figures
Phys.Rev.D68:074002,2003
10.1103/PhysRevD.68.074002
null
hep-ph
null
We investigate the flavour and quark-antiquark structure of the polarized nucleon by calculating the parton distribution functions of the nucleon sea using the meson cloud model. We find that the SU(2) flavor symmetry in the light antiquark sea and quark-antiquark symmetry in the strange quark sea are broken, {\it i.e.} $\Delta\ubar < \Delta \dbar$ and $\Delta s < \Delta \sbar$. The polarization of the strange sea is found to be positive, which is in contradiction to previous analyses. We predict a much larger quark-antiquark asymmetry in the polarized strange quark sea than that in the unpolarized strange quark sea. Our results for both polarized light quark sea and polarized strange quark sea are consistent with the recent HERMES data.
[ { "created": "Wed, 4 Jun 2003 00:18:57 GMT", "version": "v1" }, { "created": "Tue, 5 Aug 2003 03:29:42 GMT", "version": "v2" } ]
2009-03-02
[ [ "Cao", "Fu-Guang", "", "Massey University, New Zealand" ], [ "Signal", "A. I.", "", "Massey University, New Zealand" ] ]
We investigate the flavour and quark-antiquark structure of the polarized nucleon by calculating the parton distribution functions of the nucleon sea using the meson cloud model. We find that the SU(2) flavor symmetry in the light antiquark sea and quark-antiquark symmetry in the strange quark sea are broken, {\it i.e.} $\Delta\ubar < \Delta \dbar$ and $\Delta s < \Delta \sbar$. The polarization of the strange sea is found to be positive, which is in contradiction to previous analyses. We predict a much larger quark-antiquark asymmetry in the polarized strange quark sea than that in the unpolarized strange quark sea. Our results for both polarized light quark sea and polarized strange quark sea are consistent with the recent HERMES data.
hep-ph/9606477
Matt Strassler
Jonathan L. Feng and Matthew J. Strassler
Measuring SUSY Parameters at LEP II Using Chargino Production and Decay
36 pp., ReVTeX, 15 uuencoded figures
Phys.Rev. D55 (1997) 1326-1342
10.1103/PhysRevD.55.1326
LBNL--38954, UCB--PTH--96/25, RU--96--52
hep-ph
null
Previously, in the context of the minimal supersymmetric standard model (without {\em a priori} assumptions of parameter unification), we studied the constraints on weak-scale SUSY parameters from chargino production at LEP II, using as observables $\mch$, $\mLSP$, the cross section and the leptonic branching fraction. Here, exploiting the high degree of polarization in chargino production, we add to our earlier work the forward-backward asymmetries of the visible hadrons and leptons in chargino decays. For a chargino that is mostly gaugino, the parameter space can now be restricted to a small region; $\tanb$ is constrained, the soft electroweak gaugino and electron sneutrino masses are determined to about 10\%, and the sign of $\mu$ may be determined. Constraints for a chargino that is mostly Higgsino are much weaker, but still disfavor the hypothesis that the chargino is mostly gaugino. For a chargino which is a roughly equal mixture of Higgsino and gaugino, we find intermediate results.
[ { "created": "Fri, 28 Jun 1996 22:35:48 GMT", "version": "v1" } ]
2009-10-28
[ [ "Feng", "Jonathan L.", "" ], [ "Strassler", "Matthew J.", "" ] ]
Previously, in the context of the minimal supersymmetric standard model (without {\em a priori} assumptions of parameter unification), we studied the constraints on weak-scale SUSY parameters from chargino production at LEP II, using as observables $\mch$, $\mLSP$, the cross section and the leptonic branching fraction. Here, exploiting the high degree of polarization in chargino production, we add to our earlier work the forward-backward asymmetries of the visible hadrons and leptons in chargino decays. For a chargino that is mostly gaugino, the parameter space can now be restricted to a small region; $\tanb$ is constrained, the soft electroweak gaugino and electron sneutrino masses are determined to about 10\%, and the sign of $\mu$ may be determined. Constraints for a chargino that is mostly Higgsino are much weaker, but still disfavor the hypothesis that the chargino is mostly gaugino. For a chargino which is a roughly equal mixture of Higgsino and gaugino, we find intermediate results.
hep-ph/0503195
Zhiguang Xiao
Z. X. Sun, L. Y. Xiao, Z. G. Xiao and H. Q. Zheng
Model dependent analyses on the $N_c$ dependence of the $\sigma$ pole trajectory
Talk presented at Conference on Non-Perturbative Quantum Field Theory: Lattice and Beyond, Guangzhou, China, Dec.16--18, 2004
Mod.Phys.Lett.A22:711-718,2007
10.1142/S0217732307023304
null
hep-ph
null
We explore the nature of the$\sigma$ or $f_0(600)$ meson using large $N_c$ technique, assuming that the $\sigma$ pole dominates low energy physics in the IJ=00 channel. We trace the $N_c$ dependence of the $\sigma$ pole position using [1,1] Pad\'e approximation of SU(3) chiral amplitude, [1,2] Pad\'e approximation of SU(2) chiral amplitudes, and the PKU parametrization form. We find that in all 3 cases the $\sigma$ pole moves to the real axis of the complex $s$-plane. Finally we construct a pedagogical example using the SU(2) Pad\'e amplitude to show that when the analyticity property of the scattering amplitude is violated, it is possible that the $\sigma$ pole resides on the complex $s$ plane when $N_c$ is large.
[ { "created": "Sat, 19 Mar 2005 16:50:05 GMT", "version": "v1" } ]
2008-11-26
[ [ "Sun", "Z. X.", "" ], [ "Xiao", "L. Y.", "" ], [ "Xiao", "Z. G.", "" ], [ "Zheng", "H. Q.", "" ] ]
We explore the nature of the$\sigma$ or $f_0(600)$ meson using large $N_c$ technique, assuming that the $\sigma$ pole dominates low energy physics in the IJ=00 channel. We trace the $N_c$ dependence of the $\sigma$ pole position using [1,1] Pad\'e approximation of SU(3) chiral amplitude, [1,2] Pad\'e approximation of SU(2) chiral amplitudes, and the PKU parametrization form. We find that in all 3 cases the $\sigma$ pole moves to the real axis of the complex $s$-plane. Finally we construct a pedagogical example using the SU(2) Pad\'e amplitude to show that when the analyticity property of the scattering amplitude is violated, it is possible that the $\sigma$ pole resides on the complex $s$ plane when $N_c$ is large.
1910.03606
Ilaria Brivio
I. Brivio, S. Bruggisser, F. Maltoni, R. Moutafis, T. Plehn, E. Vryonidou, S. Westhoff, C. Zhang
O new physics, where art thou? A global search in the top sector
47 pages, 14 figures, 9 tables
null
10.1007/JHEP02(2020)131
P3H-19-036
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a comprehensive global analysis of Run II top measurements at the LHC in terms of dimension-6 operators. A distinctive feature of the top sector as compared to the Higgs-electroweak sector is the large number of four-quark operators. We discuss in detail how they can be tested and how quadratic terms lead to a stable limit on each individual Wilson coefficient. Predictions for all observables are computed at NLO in QCD. Our SFitter analysis framework features a detailed error treatment and shows that theoretical uncertainties are a limiting factor.
[ { "created": "Tue, 8 Oct 2019 18:01:30 GMT", "version": "v1" } ]
2020-03-18
[ [ "Brivio", "I.", "" ], [ "Bruggisser", "S.", "" ], [ "Maltoni", "F.", "" ], [ "Moutafis", "R.", "" ], [ "Plehn", "T.", "" ], [ "Vryonidou", "E.", "" ], [ "Westhoff", "S.", "" ], [ "Zhang", "C.", ...
We provide a comprehensive global analysis of Run II top measurements at the LHC in terms of dimension-6 operators. A distinctive feature of the top sector as compared to the Higgs-electroweak sector is the large number of four-quark operators. We discuss in detail how they can be tested and how quadratic terms lead to a stable limit on each individual Wilson coefficient. Predictions for all observables are computed at NLO in QCD. Our SFitter analysis framework features a detailed error treatment and shows that theoretical uncertainties are a limiting factor.
hep-ph/9206260
null
Robert H. Brandenberger (Brown) and Anne-Christine Davis (DAMTP, Cambridge)
Electroweak Baryogenesis with a Second Order Phase Transition
7 pages, use phyzzx, BROWN-HET-865
null
null
null
hep-ph astro-ph
null
If stable electroweak strings are copiously produced during the electroweak phase transition, they may contribute significantly to the presently observed baryon to entropy ratio of the universe. This analysis establishes the feasibility of implementing an electroweak baryogenesis scenario without a first order phase transition.
[ { "created": "Mon, 29 Jun 1992 13:31:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Brandenberger", "Robert H.", "", "Brown" ], [ "Davis", "Anne-Christine", "", "DAMTP,\n Cambridge" ] ]
If stable electroweak strings are copiously produced during the electroweak phase transition, they may contribute significantly to the presently observed baryon to entropy ratio of the universe. This analysis establishes the feasibility of implementing an electroweak baryogenesis scenario without a first order phase transition.
2208.07814
Congqiao Li
Congqiao Li, Huilin Qu, Sitian Qian, Qi Meng, Shiqi Gong, Jue Zhang, Tie-Yan Liu, Qiang Li
Does Lorentz-symmetric design boost network performance in jet physics?
16 pages, 7 figures
Phys. Rev. D 109, 056003 (2024)
10.1103/PhysRevD.109.056003
null
hep-ph hep-ex physics.data-an
http://creativecommons.org/licenses/by/4.0/
In the deep learning era, improving the neural network performance in jet physics is a rewarding task as it directly contributes to more accurate physics measurements at the LHC. Recent research has proposed various network designs in consideration of the full Lorentz symmetry, but its benefit is still not systematically asserted, given that there remain many successful networks without taking it into account. We conduct a detailed study on the Lorentz-symmetric design. We propose two generalized approaches for modifying a network - these methods are experimented on Particle Flow Network, ParticleNet, and LorentzNet, and exhibit a general performance gain. We also reveal that the notable improvement attributed to the "pairwise mass" feature in the network is due to its introduction of a structure that fully complies with Lorentz symmetry. We confirm that Lorentz-symmetry preservation serves as a strong inductive bias of jet physics, hence calling for attention to such general recipes in future network designs.
[ { "created": "Tue, 16 Aug 2022 15:53:53 GMT", "version": "v1" }, { "created": "Thu, 11 Jan 2024 19:13:47 GMT", "version": "v2" }, { "created": "Thu, 7 Mar 2024 19:03:03 GMT", "version": "v3" } ]
2024-03-11
[ [ "Li", "Congqiao", "" ], [ "Qu", "Huilin", "" ], [ "Qian", "Sitian", "" ], [ "Meng", "Qi", "" ], [ "Gong", "Shiqi", "" ], [ "Zhang", "Jue", "" ], [ "Liu", "Tie-Yan", "" ], [ "Li", "Qiang", ""...
In the deep learning era, improving the neural network performance in jet physics is a rewarding task as it directly contributes to more accurate physics measurements at the LHC. Recent research has proposed various network designs in consideration of the full Lorentz symmetry, but its benefit is still not systematically asserted, given that there remain many successful networks without taking it into account. We conduct a detailed study on the Lorentz-symmetric design. We propose two generalized approaches for modifying a network - these methods are experimented on Particle Flow Network, ParticleNet, and LorentzNet, and exhibit a general performance gain. We also reveal that the notable improvement attributed to the "pairwise mass" feature in the network is due to its introduction of a structure that fully complies with Lorentz symmetry. We confirm that Lorentz-symmetry preservation serves as a strong inductive bias of jet physics, hence calling for attention to such general recipes in future network designs.
hep-ph/0503108
Gerhard Ecker
V. Cirigliano, G. Ecker, M. Eidemuller, R. Kaiser, A. Pich, J. Portoles
The < S P P > Green function and SU(3) breaking in K_{l3} decays
18 pages, published version: results and conclusions unchanged
JHEP 0504:006,2005
10.1088/1126-6708/2005/04/006
Caltech MAP-306, UWThPh-2005-2, IFIC/05-12, FTUV/05-0309
hep-ph
null
Using the 1/N_C expansion scheme and truncating the hadronic spectrum to the lowest-lying resonances, we match a meromorphic approximation to the < S P P > Green function onto QCD by imposing the correct large-momentum falloff, both off-shell and on the relevant hadron mass shells. In this way we determine a number of chiral low-energy constants of O(p^6), in particular the ones governing SU(3) breaking in the K_{l3} vector form factor at zero momentum transfer. The main result of our matching procedure is that the known loop contributions largely dominate the corrections of O(p^6) to f_{+}(0). We discuss the implications of our final value f_{+}^{K^0 \pi^-}(0)=0.984 \pm 0.012 for the extraction of V_{us} from K_{l3} decays.
[ { "created": "Fri, 11 Mar 2005 17:29:39 GMT", "version": "v1" }, { "created": "Sat, 12 Mar 2005 13:40:48 GMT", "version": "v2" }, { "created": "Thu, 28 Apr 2005 08:21:31 GMT", "version": "v3" } ]
2011-05-05
[ [ "Cirigliano", "V.", "" ], [ "Ecker", "G.", "" ], [ "Eidemuller", "M.", "" ], [ "Kaiser", "R.", "" ], [ "Pich", "A.", "" ], [ "Portoles", "J.", "" ] ]
Using the 1/N_C expansion scheme and truncating the hadronic spectrum to the lowest-lying resonances, we match a meromorphic approximation to the < S P P > Green function onto QCD by imposing the correct large-momentum falloff, both off-shell and on the relevant hadron mass shells. In this way we determine a number of chiral low-energy constants of O(p^6), in particular the ones governing SU(3) breaking in the K_{l3} vector form factor at zero momentum transfer. The main result of our matching procedure is that the known loop contributions largely dominate the corrections of O(p^6) to f_{+}(0). We discuss the implications of our final value f_{+}^{K^0 \pi^-}(0)=0.984 \pm 0.012 for the extraction of V_{us} from K_{l3} decays.
0805.4074
Xiang Liu
Zhi-Gang Luo, Xiao-Lin Chen, Xiang Liu and Shi-Lin Zhu
Semileptonic decays of $B_{s1}$, $B_{s2}^*$, $B_{s0}$ and $B_{s1}'$
11 pages, 3 figures, 9 tables. More discussion added, some descriptions changed. The version to appear in EPJC
Eur.Phys.J.C60:403-411,2009
10.1140/epjc/s10052-009-0940-3
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Stimulated by recent observations of the excited bottom-strange mesons $B_{s1}$ and $B_{s2}^*$, we calculate the semileptonic decays $B_{s0}, B_{s1}^{\prime}, B_{s1}, B_{s2}^*\to [D_s(1968), D_{s}^*(2112), D_{sJ}(2317), D_{sJ}(2460)]\ell\bar{\nu}$, which is relevant for the exploration of the potential of searching these semileptonic decays in experiment.
[ { "created": "Tue, 27 May 2008 08:58:10 GMT", "version": "v1" }, { "created": "Thu, 29 May 2008 07:44:50 GMT", "version": "v2" }, { "created": "Sat, 12 Jul 2008 13:22:20 GMT", "version": "v3" }, { "created": "Thu, 4 Sep 2008 10:59:22 GMT", "version": "v4" }, { "cr...
2009-03-21
[ [ "Luo", "Zhi-Gang", "" ], [ "Chen", "Xiao-Lin", "" ], [ "Liu", "Xiang", "" ], [ "Zhu", "Shi-Lin", "" ] ]
Stimulated by recent observations of the excited bottom-strange mesons $B_{s1}$ and $B_{s2}^*$, we calculate the semileptonic decays $B_{s0}, B_{s1}^{\prime}, B_{s1}, B_{s2}^*\to [D_s(1968), D_{s}^*(2112), D_{sJ}(2317), D_{sJ}(2460)]\ell\bar{\nu}$, which is relevant for the exploration of the potential of searching these semileptonic decays in experiment.
1305.0790
Sho Iwamoto
Sho Iwamoto
Supersymmetry after the Higgs discovery and its LHC phenomenology
Dissertation submitted to Department of Physics, University of Tokyo (Dec. 2012). English, 114 pages. Based on arXiv:1108.3071, arXiv:1112.5653, arXiv:1202.2751 and arXiv:1212.3935
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Under the minimal SUSY standard model (MSSM), the discrepancy in the muon g-2 suggests the SUSY particles are of order 100 GeV, which is also supported by discussions on the little hierarchy problem. However, the LHC experiments have found no scalar-quarks or gluinos in such mass range, and moreover, the Higgs boson mass of 126 GeV requires, within the MSSM framework, the scalar-top mass of order 1-10 TeV. This current status forces us to abandon the simplest supersymmetry-breaking frameworks of the CMSSM and the GMSB scenarios. The V-MSSM is investigated in this dissertation, which is proposed as an extension of the MSSM with a (10 + 10bar) pair of the SU(5) decuplets. In the framework the Higgs mass is increased by effect from the extra matters, and thus the 126 GeV is achieved with the scalar-top having a lighter mass. This fact resurrects the CMSSM and the GMSB scenarios. This dissertation examines the GMSB scenario under the V-MSSM; it is called V-GMSB scenario. It is shown that the V-GMSB has a potential to realize the 126 GeV mass of the Higgs boson with holding the explanation of the muon magnetic moment discrepancy, if the masses of the extra quarks are approximately less than 1.2 TeV. Constraints on the V-GMSB from the LHC experiments are discussed then; it is concluded that the gluino mass must be approximately heavier than 1.1 TeV, and that the extra quarks be heavier than 300-650 GeV depending on the decay branches of them. LHC prospects are briefly discussed. As the extra quarks are expected to be approximately less than 1.2 TeV, searches for the particles are of great interest at the 14 TeV LHC; constraints from the supersymmetry search, especially on the gluino mass, are expected to be much improved there. Therefore, it is expected that the fate of the V-GMSB is adjudicated at the court of the 14 TeV LHC.
[ { "created": "Fri, 3 May 2013 18:11:53 GMT", "version": "v1" } ]
2013-05-06
[ [ "Iwamoto", "Sho", "" ] ]
Under the minimal SUSY standard model (MSSM), the discrepancy in the muon g-2 suggests the SUSY particles are of order 100 GeV, which is also supported by discussions on the little hierarchy problem. However, the LHC experiments have found no scalar-quarks or gluinos in such mass range, and moreover, the Higgs boson mass of 126 GeV requires, within the MSSM framework, the scalar-top mass of order 1-10 TeV. This current status forces us to abandon the simplest supersymmetry-breaking frameworks of the CMSSM and the GMSB scenarios. The V-MSSM is investigated in this dissertation, which is proposed as an extension of the MSSM with a (10 + 10bar) pair of the SU(5) decuplets. In the framework the Higgs mass is increased by effect from the extra matters, and thus the 126 GeV is achieved with the scalar-top having a lighter mass. This fact resurrects the CMSSM and the GMSB scenarios. This dissertation examines the GMSB scenario under the V-MSSM; it is called V-GMSB scenario. It is shown that the V-GMSB has a potential to realize the 126 GeV mass of the Higgs boson with holding the explanation of the muon magnetic moment discrepancy, if the masses of the extra quarks are approximately less than 1.2 TeV. Constraints on the V-GMSB from the LHC experiments are discussed then; it is concluded that the gluino mass must be approximately heavier than 1.1 TeV, and that the extra quarks be heavier than 300-650 GeV depending on the decay branches of them. LHC prospects are briefly discussed. As the extra quarks are expected to be approximately less than 1.2 TeV, searches for the particles are of great interest at the 14 TeV LHC; constraints from the supersymmetry search, especially on the gluino mass, are expected to be much improved there. Therefore, it is expected that the fate of the V-GMSB is adjudicated at the court of the 14 TeV LHC.
hep-ph/0112326
Jeff Greensite
J. Greensite and Charles B. Thorn
Gluon Chain Model of the Confining Force
25 pages, 5 figures, latex2e
JHEP 0202:014,2002
10.1088/1126-6708/2002/02/014
LBNL-49311, UFIFT-HEP-01-26
hep-ph hep-lat hep-th
null
We develop a picture of the QCD string as a chain of constituent gluons, bound by attractive nearest-neighbor forces which may be treated perturbatively. This picture accounts for both Casimir scaling at large N, and the asymptotic center dependence of the static quark potential. We discuss the relevance, to the gluon-chain picture, of recent three-loop results for the static quark potential. A variational framework is presented for computing the minimal energy and wavefunction of a long gluon chain, which enables us to derive both the logarithmic broadening of the QCD flux tube (``roughening''), and the existence of a Luscher -c/R term in the potential.
[ { "created": "Tue, 25 Dec 2001 19:25:02 GMT", "version": "v1" } ]
2014-11-17
[ [ "Greensite", "J.", "" ], [ "Thorn", "Charles B.", "" ] ]
We develop a picture of the QCD string as a chain of constituent gluons, bound by attractive nearest-neighbor forces which may be treated perturbatively. This picture accounts for both Casimir scaling at large N, and the asymptotic center dependence of the static quark potential. We discuss the relevance, to the gluon-chain picture, of recent three-loop results for the static quark potential. A variational framework is presented for computing the minimal energy and wavefunction of a long gluon chain, which enables us to derive both the logarithmic broadening of the QCD flux tube (``roughening''), and the existence of a Luscher -c/R term in the potential.
hep-ph/9906483
Monique Werlen
M. Werlen
Inclusive Photon Production in Hadronic Collisions
5 pages, 4 figures, Moriond QCD 1999
null
null
LAPTH-Conf-734/99
hep-ph
null
High statistics fixed target and ISR inclusive photon production data are compared to next-to-leading order (NLO) QCD calculations. The dependence of the theoretical predictions on the structure functions, and on the theoretical scales is investigated. It is shown that the data cannot be simultaneously fitted with a single set of structure functions and scales. However, it is argued that as long as one restricts the data/theory comparison to the xT range where the theory is reliable, i.e. stable with respect to the scale variation, there is no need to introduce an additional primordial kT dependence except for Be data. Finally a precise determination of the strong coupling constant, alpha_s, is performed from the direct photon production cross sections obtained in high statistics pbar p and pp collisions at the CERN SPS (UA6) by a NLO QCD analysis.
[ { "created": "Thu, 24 Jun 1999 13:56:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Werlen", "M.", "" ] ]
High statistics fixed target and ISR inclusive photon production data are compared to next-to-leading order (NLO) QCD calculations. The dependence of the theoretical predictions on the structure functions, and on the theoretical scales is investigated. It is shown that the data cannot be simultaneously fitted with a single set of structure functions and scales. However, it is argued that as long as one restricts the data/theory comparison to the xT range where the theory is reliable, i.e. stable with respect to the scale variation, there is no need to introduce an additional primordial kT dependence except for Be data. Finally a precise determination of the strong coupling constant, alpha_s, is performed from the direct photon production cross sections obtained in high statistics pbar p and pp collisions at the CERN SPS (UA6) by a NLO QCD analysis.
1210.2624
David R. Entem
J. Segovia, D. R. Entem, F. Fern\'andez, E. Ruiz Arriola
Renormalized Quarkonium
7 pages, accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.86.094027
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend our previous study of the vector charmonium states within a renormalization approach with boundary conditions to the full spectrum of charmonium and bottomonium. On the light of the predicted spectrum we comply to assignments suggested in the literature. A comparison with the regularized quark model is also included.
[ { "created": "Tue, 9 Oct 2012 14:58:10 GMT", "version": "v1" } ]
2015-06-11
[ [ "Segovia", "J.", "" ], [ "Entem", "D. R.", "" ], [ "Fernández", "F.", "" ], [ "Arriola", "E. Ruiz", "" ] ]
We extend our previous study of the vector charmonium states within a renormalization approach with boundary conditions to the full spectrum of charmonium and bottomonium. On the light of the predicted spectrum we comply to assignments suggested in the literature. A comparison with the regularized quark model is also included.
hep-ph/0703089
Seung-Il Nam
Seung-il Nam and Hyun-Chul Kim
Kaon semileptonic decay (K_{l3}) form factors from the instanton vacuum
12 pages, 3 figures, submitted to PRD
Phys.Rev.D75:094011,2007
10.1103/PhysRevD.75.094011
PNU-NTG-02/2007, PNU-NuRI-02/2007
hep-ph
null
We investigate the kaon semileptonic decay (K_{l3}) form factors within the framework of the nonlocal chiral quark model from the instanton vacuum, taking into account the effects of flavor SU(3) symmetry breaking. We also consider the problem of gauge invariance arising from the momentum-dependent quark mass in the present work. All theoretical calculations are carried out without any adjustable parameter, the average instanton size (rho ~ 1/3 fm) and the inter-instanton distance (R ~ 1 fm) having been fixed. We also show that the present results satisfy the Callan-Treiman low-energy theorem as well as the Ademollo-Gatto theorem. Using the K_{l3} form factors, we evaluate relevant physical quantities. It turns out that the effects of flavor SU(3) symmetry breaking are essential in reproducing the kaon semileptonic form factors. The present results are in a good agreement with experiments, and are compatible with other model calculations.
[ { "created": "Thu, 8 Mar 2007 08:04:18 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nam", "Seung-il", "" ], [ "Kim", "Hyun-Chul", "" ] ]
We investigate the kaon semileptonic decay (K_{l3}) form factors within the framework of the nonlocal chiral quark model from the instanton vacuum, taking into account the effects of flavor SU(3) symmetry breaking. We also consider the problem of gauge invariance arising from the momentum-dependent quark mass in the present work. All theoretical calculations are carried out without any adjustable parameter, the average instanton size (rho ~ 1/3 fm) and the inter-instanton distance (R ~ 1 fm) having been fixed. We also show that the present results satisfy the Callan-Treiman low-energy theorem as well as the Ademollo-Gatto theorem. Using the K_{l3} form factors, we evaluate relevant physical quantities. It turns out that the effects of flavor SU(3) symmetry breaking are essential in reproducing the kaon semileptonic form factors. The present results are in a good agreement with experiments, and are compatible with other model calculations.
hep-ph/0607086
Dan Hooper
Dan Hooper and Andrew M. Taylor
Determining Supersymmetric Parameters With Dark Matter Experiments
46 pages, 76 figures
JCAP 0703:017,2007
10.1088/1475-7516/2007/03/017
FERMILAB-PUB-06-198-A
hep-ph astro-ph
null
In this article, we explore the ability of direct and indirect dark matter experiments to not only detect neutralino dark matter, but to constrain and measure the parameters of supersymmetry. In particular, we explore the relationship between the phenomenological quantities relevant to dark matter experiments, such as the neutralino annihilation and elastic scattering cross sections, and the underlying characteristics of the supersymmetric model, such as the values of mu (and the composition of the lightest neutralino), m_A and tan beta. We explore a broad range of supersymmetric models and then focus on a smaller set of benchmark models. We find that by combining astrophysical observations with collider measurements, mu can often be constrained far more tightly than it can be from LHC data alone. In models in the A-funnel region of parameter space, we find that dark matter experiments can potentially determine m_A to roughly +/-100 GeV, even when heavy neutral MSSM Higgs bosons (A, H_1) cannot be observed at the LHC. The information provided by astrophysical experiments is often highly complementary to the information most easily ascertained at colliders.
[ { "created": "Fri, 7 Jul 2006 20:14:33 GMT", "version": "v1" } ]
2014-11-18
[ [ "Hooper", "Dan", "" ], [ "Taylor", "Andrew M.", "" ] ]
In this article, we explore the ability of direct and indirect dark matter experiments to not only detect neutralino dark matter, but to constrain and measure the parameters of supersymmetry. In particular, we explore the relationship between the phenomenological quantities relevant to dark matter experiments, such as the neutralino annihilation and elastic scattering cross sections, and the underlying characteristics of the supersymmetric model, such as the values of mu (and the composition of the lightest neutralino), m_A and tan beta. We explore a broad range of supersymmetric models and then focus on a smaller set of benchmark models. We find that by combining astrophysical observations with collider measurements, mu can often be constrained far more tightly than it can be from LHC data alone. In models in the A-funnel region of parameter space, we find that dark matter experiments can potentially determine m_A to roughly +/-100 GeV, even when heavy neutral MSSM Higgs bosons (A, H_1) cannot be observed at the LHC. The information provided by astrophysical experiments is often highly complementary to the information most easily ascertained at colliders.
0704.3340
Anirban Kundu
Biplob Bhattacherjee and Anirban Kundu
Production of Higgs boson excitations of universal extra dimension at the Large Hadron Collider
11 pages, 5 figures, the discussion on possible backgrounds has been considerably extended, some new references added, version to be published in PLB
Phys.Lett.B653:300-306,2007
10.1016/j.physletb.2007.07.062
CU-PHYSICS/07-2007
hep-ph
null
The Kaluza-Klein excitations of the Higgs bosons of the universal extra dimension model are extremely challenging to detect. We discuss the production and possible detection mechanisms of such excited scalars at the LHC. The dominant production mechanism of such scalars is from the decay of the excited third generation quarks. In particular, the charged Higgs boson has a large production cross-section over most of the parameter space. We highlight how one may detect these excited scalars. We also comment on the production and detection of excited neutral scalars.
[ { "created": "Wed, 25 Apr 2007 10:37:08 GMT", "version": "v1" }, { "created": "Thu, 26 Jul 2007 07:53:04 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bhattacherjee", "Biplob", "" ], [ "Kundu", "Anirban", "" ] ]
The Kaluza-Klein excitations of the Higgs bosons of the universal extra dimension model are extremely challenging to detect. We discuss the production and possible detection mechanisms of such excited scalars at the LHC. The dominant production mechanism of such scalars is from the decay of the excited third generation quarks. In particular, the charged Higgs boson has a large production cross-section over most of the parameter space. We highlight how one may detect these excited scalars. We also comment on the production and detection of excited neutral scalars.
hep-ph/0311170
Jonathan Rosner
Jonathan L. Rosner
Learning the weak phase $\gamma$ from B decays
7 pages, 9 figures, talk given at the 9th International Conference on B-Physics at Hadron Machines (BEAUTY 2003), CMU, Pittsburgh, October 2003. Some branching ratios updated, leading to slight changes in two figures
AIP Conf.Proc.722:35-41,2004
10.1063/1.1807293
CLNS 03/1851
hep-ph
null
The current status of some methods to determine the weak phase $\gamma$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $V^*_{ub}$ using B decays is discussed, and comments are made on accuracy achievable in the next few years.
[ { "created": "Thu, 13 Nov 2003 16:14:29 GMT", "version": "v1" }, { "created": "Wed, 19 Nov 2003 14:49:51 GMT", "version": "v2" }, { "created": "Thu, 4 Dec 2003 19:44:20 GMT", "version": "v3" } ]
2014-11-17
[ [ "Rosner", "Jonathan L.", "" ] ]
The current status of some methods to determine the weak phase $\gamma$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $V^*_{ub}$ using B decays is discussed, and comments are made on accuracy achievable in the next few years.
hep-ph/9504373
Alessandro Strumia
Riccardo Barbieri, Lawrence Hall and Alessandro Strumia
Hadronic Flavor and CP Violating Signals of Superunification
17 pages, figures not included
Nucl.Phys.B449:437-461,1995
10.1016/0550-3213(95)00311-F
LBL-36907 and IFUP - TH 13/95
hep-ph
null
The flavor changing and CP violating phenomena predicted in supersymmetric unified theories as a consequence of the large top quark Yukawa coupling, are investigated in the quark sector and compared with related phenomena in the lepton sector, considered previously. In particular we study $\varepsilon_K$, $\varepsilon_K'/\varepsilon_K$, $\Delta m_B$, $b\to s\gamma$, the neutron electric dipole moment, $d_n$, and CP violation in neutral $B$ meson decays, both in minimal~SU(5) and~SO(10) theories. The leptonic signals are generically shown to provide more significant tests of quark-lepton unification. Nevertheless, mostly in the~SO(10) case, a variety of hadronic signals is also possible, with interesting correlations among them.
[ { "created": "Mon, 24 Apr 1995 10:51:23 GMT", "version": "v1" } ]
2009-10-09
[ [ "Barbieri", "Riccardo", "" ], [ "Hall", "Lawrence", "" ], [ "Strumia", "Alessandro", "" ] ]
The flavor changing and CP violating phenomena predicted in supersymmetric unified theories as a consequence of the large top quark Yukawa coupling, are investigated in the quark sector and compared with related phenomena in the lepton sector, considered previously. In particular we study $\varepsilon_K$, $\varepsilon_K'/\varepsilon_K$, $\Delta m_B$, $b\to s\gamma$, the neutron electric dipole moment, $d_n$, and CP violation in neutral $B$ meson decays, both in minimal~SU(5) and~SO(10) theories. The leptonic signals are generically shown to provide more significant tests of quark-lepton unification. Nevertheless, mostly in the~SO(10) case, a variety of hadronic signals is also possible, with interesting correlations among them.
1612.01792
Matthias Jamin
Diogo Boito, Matthias Jamin, Ramon Miravitllas
Scheme variations of the QCD coupling
10 pages, 6 figures, proceedings of XIIth Quark Confinement and the Hadron Spectrum, 28 August - 4 September (2016), Thessaloniki (Greece)
null
10.1051/epjconf/201713705007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Quantum Chromodynamics (QCD) coupling $\alpha_s$ is a central parameter in the Standard Model of particle physics. However, it depends on theoretical conventions related to renormalisation and hence is not an observable quantity. In order to capture this dependence in a transparent way, a novel definition of the QCD coupling, denoted by $\hat a$, is introduced, whose running is explicitly renormalisation scheme invariant. The remaining renormalisation scheme dependence is related to transformations of the QCD scale $\Lambda$, and can be parametrised by a single parameter $C$. Hence, we call $\hat a$ the $C$-scheme coupling. The dependence on $C$ can be exploited to study and improve perturbative predictions of physical observables. This is demonstrated for the QCD Adler function and hadronic decays of the $\tau$ lepton.
[ { "created": "Tue, 6 Dec 2016 13:08:06 GMT", "version": "v1" } ]
2017-04-05
[ [ "Boito", "Diogo", "" ], [ "Jamin", "Matthias", "" ], [ "Miravitllas", "Ramon", "" ] ]
The Quantum Chromodynamics (QCD) coupling $\alpha_s$ is a central parameter in the Standard Model of particle physics. However, it depends on theoretical conventions related to renormalisation and hence is not an observable quantity. In order to capture this dependence in a transparent way, a novel definition of the QCD coupling, denoted by $\hat a$, is introduced, whose running is explicitly renormalisation scheme invariant. The remaining renormalisation scheme dependence is related to transformations of the QCD scale $\Lambda$, and can be parametrised by a single parameter $C$. Hence, we call $\hat a$ the $C$-scheme coupling. The dependence on $C$ can be exploited to study and improve perturbative predictions of physical observables. This is demonstrated for the QCD Adler function and hadronic decays of the $\tau$ lepton.
hep-ph/0402043
Jihn E. Kim
Jihn E. Kim
Self-tuning of cosmological constant and exit from inflation
Latex file of 8 pages, including 2 figures. Talk presented at COSPA-03, Taipei, Taiwan, Nov. 13-15, 2003
Mod.Phys.Lett. A19 (2004) 1039-1046
10.1142/S0217732304014343
SNUTP 04-002
hep-ph
null
I review the recent 5D self-tuning solutions of the cosmological constant problem, and try to unify two cosmological constant problems within the framework of the self-tuning solutions. One problem, the large cosmological constant needed for inflation, is interpreted by starting with the parameters allowing only the dS vacuum, and the vanishing cosmological constant at a true vacuum is realized by changing parameters by exit from inflation at the brane such that the self-tuning solution is allowed.
[ { "created": "Wed, 4 Feb 2004 14:25:26 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kim", "Jihn E.", "" ] ]
I review the recent 5D self-tuning solutions of the cosmological constant problem, and try to unify two cosmological constant problems within the framework of the self-tuning solutions. One problem, the large cosmological constant needed for inflation, is interpreted by starting with the parameters allowing only the dS vacuum, and the vanishing cosmological constant at a true vacuum is realized by changing parameters by exit from inflation at the brane such that the self-tuning solution is allowed.
1612.00264
Alexander Titov I.
Alexander I. Titov, Burkhard Kampfer, Atsushi Hosaka, and Hideaki Takabe
Non-linear quantum dynamics in strong and short electromagnetic fields
Lecture given at Helmholtz - DIAS International Summer School Quantum Field Theory at the Limits: from Strong Fields to Heavy Quarks, July 18-30, 2016, Dubna, Russia. 10 pages, 4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In our contribution we give a brief overview of two widely discussed quantum processes: electron-positron pairs production off a probe photon propagating through a polarized short-pulsed electromagnetic (e.m.) (e.g.\ laser) wave field or generalized Breit-Wheeler process and a single a photon emission off an electron interacting with the laser pules, so-called non-linear Compton scattering. We show that at small and moderate laser field intensities the shape and duration of the pulse are very important for the probability of considered processes. However, at high intensities the multi-photon interactions of the fermions with laser field are decisive and completely determined all aspects of subthreshold electron-positron pairs and photon production
[ { "created": "Thu, 1 Dec 2016 14:24:33 GMT", "version": "v1" } ]
2016-12-02
[ [ "Titov", "Alexander I.", "" ], [ "Kampfer", "Burkhard", "" ], [ "Hosaka", "Atsushi", "" ], [ "Takabe", "Hideaki", "" ] ]
In our contribution we give a brief overview of two widely discussed quantum processes: electron-positron pairs production off a probe photon propagating through a polarized short-pulsed electromagnetic (e.m.) (e.g.\ laser) wave field or generalized Breit-Wheeler process and a single a photon emission off an electron interacting with the laser pules, so-called non-linear Compton scattering. We show that at small and moderate laser field intensities the shape and duration of the pulse are very important for the probability of considered processes. However, at high intensities the multi-photon interactions of the fermions with laser field are decisive and completely determined all aspects of subthreshold electron-positron pairs and photon production
2401.05278
Damiano Francesco Giuseppe Fiorillo
Damiano F. G. Fiorillo, Georg G. Raffelt, G\"unter Sigl
Inhomogeneous Kinetic Equation for Mixed Neutrinos: Tracing the Missing Energy
Small changes to the text, version published on Physical Review Letters; 5 pages, 1 figures, plus Supplemental Material
Phys.Rev.Lett. 133 (2024) 2, 021002
null
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavor-dependent neutrino transport is described by a well-known kinetic equation for occupation-number matrices in flavor space. However, as an overlooked theoretical problem, we show that in the inhomogeneous case, neutrino-neutrino refractive energy is not conserved. We derive the missing gradient terms in the fast flavor limit (vanishing neutrino masses), and prove that the missing refractive energy is traded with the huge reservoir of neutrino kinetic energy through gradients of the weak interaction potential. Even small changes of the kinetic energy accommodate the refractive energy gained or lost. Flavor evolution alone is negligibly affected by the new terms.
[ { "created": "Wed, 10 Jan 2024 17:20:06 GMT", "version": "v1" }, { "created": "Tue, 30 Jul 2024 03:44:31 GMT", "version": "v2" } ]
2024-07-31
[ [ "Fiorillo", "Damiano F. G.", "" ], [ "Raffelt", "Georg G.", "" ], [ "Sigl", "Günter", "" ] ]
Flavor-dependent neutrino transport is described by a well-known kinetic equation for occupation-number matrices in flavor space. However, as an overlooked theoretical problem, we show that in the inhomogeneous case, neutrino-neutrino refractive energy is not conserved. We derive the missing gradient terms in the fast flavor limit (vanishing neutrino masses), and prove that the missing refractive energy is traded with the huge reservoir of neutrino kinetic energy through gradients of the weak interaction potential. Even small changes of the kinetic energy accommodate the refractive energy gained or lost. Flavor evolution alone is negligibly affected by the new terms.
2407.17670
Oleh Savchuk
Oleh Savchuk
Net-proton fluctuations influenced by baryon stopping and quark deconfinement
10 pages, 3 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Preliminary data from the Beam-Energy Scan II measurements by the STAR Collaboration at the Relativistic Heavy Ion Collider suggest a dip in the fourth-to-second-order cumulant ratio when plotted vs. beam energy. At the same energy range where the structure appears, a transition from hadrons to quarks is expected, the deconfinement transition. In this paper, the role of quark deconfinement in establishing fluctuaitions in the early stages of the collision is considered. Two models are compared: one with stopping occurring on a baryon-by-baryon basis, and a second where stopping proceeds through quark degrees of freedom. In the latter model, the fluctuation of baryon number is significantly reduced and this signal is found to survive recombination into hadrons and the subsequent diffusion. The transformation from baryon to quark stopping thus produces a dip in the fourth-to-second-order cumulant ratio when plotted vs. beam energy, consistent with observations.
[ { "created": "Wed, 24 Jul 2024 23:21:45 GMT", "version": "v1" }, { "created": "Mon, 29 Jul 2024 01:12:40 GMT", "version": "v2" } ]
2024-07-30
[ [ "Savchuk", "Oleh", "" ] ]
Preliminary data from the Beam-Energy Scan II measurements by the STAR Collaboration at the Relativistic Heavy Ion Collider suggest a dip in the fourth-to-second-order cumulant ratio when plotted vs. beam energy. At the same energy range where the structure appears, a transition from hadrons to quarks is expected, the deconfinement transition. In this paper, the role of quark deconfinement in establishing fluctuaitions in the early stages of the collision is considered. Two models are compared: one with stopping occurring on a baryon-by-baryon basis, and a second where stopping proceeds through quark degrees of freedom. In the latter model, the fluctuation of baryon number is significantly reduced and this signal is found to survive recombination into hadrons and the subsequent diffusion. The transformation from baryon to quark stopping thus produces a dip in the fourth-to-second-order cumulant ratio when plotted vs. beam energy, consistent with observations.
1803.07795
Chao-Yi L\"u
Chao-Yi L\"u, P. Wang, Y. B. Dong, P. N. Shen, Z. Y. Zhang and D. M. Li
Phenomenological study on the decay widths of $\Upsilon(nS)\rightarrow \bar{d}^{\ast}(2380)+X$
null
Chinese Physics C Vol. 42, No. 6 (2018) 064102
10.1088/1674-1137/42/6/064102
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay widths of $\Upsilon(nS)$ $\rightarrow$ $\bar{d}^{\ast}(2380)+X$ with $n=1,2,3$ are studied in a phenomenological way. With the help of crossing symmetry, the decay widths are obtained by investigating the imaginary part of the forward scattering amplitudes between $d^\ast$ and $\Upsilon(nS)$. The wave functions of $d^\ast$ and deuteron obtained in previous studies are used for calculating the amplitude. The interaction between $d^{\ast}$ ($d$) and $\Upsilon$ is governed by the quark-meson interaction where the coupling constant is determined by fitting the observed widths of $\Upsilon(nS)$ $\rightarrow$ $\bar{d}+X$. The numerical results show that the decay widths of $\Upsilon(nS)$ $\rightarrow$ $\bar{d}^{\ast}+X$ are about $2 - 10$ times smaller than that of $\bar{d}+X$. The calculated momentum of $\bar{d^*}$ is in the range $0.3-0.8$ GeV. Therefore, it is very likely that one can find $\bar{d}^\ast(2380)$ in these semi-inclusive decay processes.
[ { "created": "Wed, 21 Mar 2018 08:33:56 GMT", "version": "v1" }, { "created": "Wed, 16 May 2018 09:18:29 GMT", "version": "v2" } ]
2018-05-17
[ [ "Lü", "Chao-Yi", "" ], [ "Wang", "P.", "" ], [ "Dong", "Y. B.", "" ], [ "Shen", "P. N.", "" ], [ "Zhang", "Z. Y.", "" ], [ "Li", "D. M.", "" ] ]
The decay widths of $\Upsilon(nS)$ $\rightarrow$ $\bar{d}^{\ast}(2380)+X$ with $n=1,2,3$ are studied in a phenomenological way. With the help of crossing symmetry, the decay widths are obtained by investigating the imaginary part of the forward scattering amplitudes between $d^\ast$ and $\Upsilon(nS)$. The wave functions of $d^\ast$ and deuteron obtained in previous studies are used for calculating the amplitude. The interaction between $d^{\ast}$ ($d$) and $\Upsilon$ is governed by the quark-meson interaction where the coupling constant is determined by fitting the observed widths of $\Upsilon(nS)$ $\rightarrow$ $\bar{d}+X$. The numerical results show that the decay widths of $\Upsilon(nS)$ $\rightarrow$ $\bar{d}^{\ast}+X$ are about $2 - 10$ times smaller than that of $\bar{d}+X$. The calculated momentum of $\bar{d^*}$ is in the range $0.3-0.8$ GeV. Therefore, it is very likely that one can find $\bar{d}^\ast(2380)$ in these semi-inclusive decay processes.
hep-ph/9512299
null
Jonathan L. Rosner
Forward-Backward Asymmetries in Hadronically Produced Lepton Pairs
11 pages, latex, 4 uuencoded figures sent separately, Fig. 2 revised
Phys.Rev. D54 (1996) 1078-1082
10.1103/PhysRevD.54.1078
FERMILAB-PUB-95/394-T, EFI-95-75
hep-ph
null
It has now become possible to observe appreciable numbers of hadronically produced lepton pairs in mass ranges where the contributions of the photon and $Z^0$ are comparable. Consequently, in the reaction $p \bar p \to \ell^- \ell^+ + \ldots$, substantial forward-backward asymmetries can be seen. These asymmetries provide a test of the electroweak theory in a new regime of energies, and can serve as diagnostics for any new neutral vector bosons coupling both to quarks and to charged lepton pairs.
[ { "created": "Wed, 13 Dec 1995 19:57:38 GMT", "version": "v1" }, { "created": "Fri, 15 Dec 1995 02:09:12 GMT", "version": "v2" } ]
2009-10-28
[ [ "Rosner", "Jonathan L.", "" ] ]
It has now become possible to observe appreciable numbers of hadronically produced lepton pairs in mass ranges where the contributions of the photon and $Z^0$ are comparable. Consequently, in the reaction $p \bar p \to \ell^- \ell^+ + \ldots$, substantial forward-backward asymmetries can be seen. These asymmetries provide a test of the electroweak theory in a new regime of energies, and can serve as diagnostics for any new neutral vector bosons coupling both to quarks and to charged lepton pairs.
1009.5250
Hyun-Chul Kim
Ghil-Seok Yang, Hyun-Chul Kim, and Maxim V. Polyakov
Electromagnetic mass differences of SU(3) baryons within a chiral soliton model
8 pages. To appear in Phys. Lett. B
Phys.Lett.B695:214-218,2011
10.1016/j.physletb.2010.11.018
INHA-NTG-09/2010
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the electromagnetic mass differences of SU(3) baryons, using an "model-independent approach" within a chiral soliton model. The electromagnetic self-energy corrections to the masses of the baryon are expressed as the baryonic two-point correlation function of the electromagnetic currents. Using the fact that the electromagnetic current can be treated as an octet operator, and considering possible irreducible representations of the correlation function, we are able to construct a general collective operator for the electromagnetic self-energies, which consists of three unknown parameters. These parameters are fixed, the empirical data for the electromagnetic mass differences of the baryon octet being employed. We predict those of the baryon decuplet and antidecuplet. In addition, we obtain various mass relations between baryon masses within the corresponding representation with isospin symmetry breaking considered. We also predict the physical mass differences of the baryon decuplet. The results are in good agreement with the exisiting data.
[ { "created": "Mon, 27 Sep 2010 13:21:35 GMT", "version": "v1" }, { "created": "Tue, 16 Nov 2010 07:43:33 GMT", "version": "v2" } ]
2011-01-28
[ [ "Yang", "Ghil-Seok", "" ], [ "Kim", "Hyun-Chul", "" ], [ "Polyakov", "Maxim V.", "" ] ]
We investigate the electromagnetic mass differences of SU(3) baryons, using an "model-independent approach" within a chiral soliton model. The electromagnetic self-energy corrections to the masses of the baryon are expressed as the baryonic two-point correlation function of the electromagnetic currents. Using the fact that the electromagnetic current can be treated as an octet operator, and considering possible irreducible representations of the correlation function, we are able to construct a general collective operator for the electromagnetic self-energies, which consists of three unknown parameters. These parameters are fixed, the empirical data for the electromagnetic mass differences of the baryon octet being employed. We predict those of the baryon decuplet and antidecuplet. In addition, we obtain various mass relations between baryon masses within the corresponding representation with isospin symmetry breaking considered. We also predict the physical mass differences of the baryon decuplet. The results are in good agreement with the exisiting data.
0805.1649
Bronislav Zakharov
B.G. Zakharov
Parton Energy Loss in Collinear Expansion
Contributed to 43rd Rencontres de Moriond on QCD and High-Energy Hadronic Interactions, La Thuile, Italy, 8-15 Mar 2008. 6 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate that the N=1 rescattering contribution to the gluon radiation from a fast massless quark in eA DIS vanishes in the collinear approximation. It is shown that the nonzero N=1 gluon spectrum obtained in the higher-twist approach by Guo, Wang and Zhang is a consequence of unjustified neglecting some important terms in the collinear expansion.
[ { "created": "Mon, 12 May 2008 14:51:40 GMT", "version": "v1" } ]
2008-05-13
[ [ "Zakharov", "B. G.", "" ] ]
We demonstrate that the N=1 rescattering contribution to the gluon radiation from a fast massless quark in eA DIS vanishes in the collinear approximation. It is shown that the nonzero N=1 gluon spectrum obtained in the higher-twist approach by Guo, Wang and Zhang is a consequence of unjustified neglecting some important terms in the collinear expansion.
1908.00426
Abdel Nasser Tawfik
Abdel Nasser Tawfik (Nile U., ECTP and Johann Wolfgang Goethe-Universitat), Muhammad Maher, A. H. El-Kateb, Sara Abdelaziz (Helwan U)
Deconfinement and freezeout boundaries in equilibrium thermal models
8 pages, 2 figures, accepted for publication in AHEP
Adv.High Energy Phys. 2020 (2020) 453476
10.1155/2020/2453476
ECTP-2019-09, WLCAPP-2019-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In different approaches, the temperature-baryon density plane of QCD matter is studied for deconfinement and chemical freezeout boundaries. Results from various heavy-ion experiments are compared with the recent lattice simulations, the effective QCD-like Polyakov linear-sigma model, and the equilibrium thermal models. Along the entire freezeout boundary, there is an excellent agreement between the thermal model calculations and the experiments. Also, the thermal model calculations agree well with the estimations deduced from the Polyakov linear-sigma model (PLSM). At low baryonic density or high energies, both deconfinement and chemical freezeout boundaries are likely coincident and therefore the agreement with the lattice simulations becomes excellent as well, while at large baryonic density, the two boundaries become distinguishable forming a phase where hadrons and quark-gluon plasma likely coexist.
[ { "created": "Thu, 1 Aug 2019 14:19:13 GMT", "version": "v1" }, { "created": "Tue, 28 Jan 2020 19:22:56 GMT", "version": "v2" } ]
2020-03-03
[ [ "Tawfik", "Abdel Nasser", "", "Nile U., ECTP and Johann Wolfgang\n Goethe-Universitat" ], [ "Maher", "Muhammad", "", "Helwan\n U" ], [ "El-Kateb", "A. H.", "", "Helwan\n U" ], [ "Abdelaziz", "Sara", "", "Helwan\n U" ] ]
In different approaches, the temperature-baryon density plane of QCD matter is studied for deconfinement and chemical freezeout boundaries. Results from various heavy-ion experiments are compared with the recent lattice simulations, the effective QCD-like Polyakov linear-sigma model, and the equilibrium thermal models. Along the entire freezeout boundary, there is an excellent agreement between the thermal model calculations and the experiments. Also, the thermal model calculations agree well with the estimations deduced from the Polyakov linear-sigma model (PLSM). At low baryonic density or high energies, both deconfinement and chemical freezeout boundaries are likely coincident and therefore the agreement with the lattice simulations becomes excellent as well, while at large baryonic density, the two boundaries become distinguishable forming a phase where hadrons and quark-gluon plasma likely coexist.
1207.2167
Boris Kayser
Boris Kayser
Tensions with the Three-Neutrino Paradigm
5 pages, LaTeX
2012 Electroweak Interactions and Unified Theories (Proceedings of the Electroweak Session of the 47th Rencontres de Moriond), (ARISF, 2012) p.191
null
FERMILAB-CONF-12-384-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the tensions with the standard three-neutrino framework for neutrino oscillation. These tensions hint at the possible existence of sterile neutrinos. We briefly describe some of the diverse ideas for probing the existence of such neutrinos in a definitive way through future experiments.
[ { "created": "Mon, 9 Jul 2012 20:18:03 GMT", "version": "v1" }, { "created": "Wed, 25 Dec 2013 03:28:20 GMT", "version": "v2" } ]
2013-12-30
[ [ "Kayser", "Boris", "" ] ]
We review the tensions with the standard three-neutrino framework for neutrino oscillation. These tensions hint at the possible existence of sterile neutrinos. We briefly describe some of the diverse ideas for probing the existence of such neutrinos in a definitive way through future experiments.
2106.08491
Shuang Li
Shuang Li, Fei Sun, Wei Xie and Wei Xiong
Langevin dynamics of heavy quarks in a soft-hard factorized approach
13 pages, 10 figures
Eur. Phys. J. C (2021) 81.536
10.1140/epjc/s10052-021-09339-7
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
By utilizing a soft-hard factorized model, which combines a thermal perturbative description of soft scatterings and a perturbative QCD-based calculation for hard collisions, we study the energy and temperature dependence of the heavy quark diffusion coefficients in Langevin dynamics. The adjustable parameters are fixed from the comprehensive model-data comparison. We find that a small value of the spatial diffusion coefficient at transition temperature is preferred by data $2\pi TD_{s}(T_{c}) \simeq 6$. With the parameter-optimized model, we are able to describe simultaneously the prompt $D^{0}$ $R_{\rm AA}$ and $v_{2}$ data at $p_{\rm T}\le8$ GeV in Pb--Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ and $\sqrt{s_{\rm NN}}=5.02$ TeV. We also make predictions for non-prompt $D^{0}$ meson for future experimental tests down to the low momentum region.
[ { "created": "Wed, 16 Jun 2021 00:14:21 GMT", "version": "v1" } ]
2021-06-24
[ [ "Li", "Shuang", "" ], [ "Sun", "Fei", "" ], [ "Xie", "Wei", "" ], [ "Xiong", "Wei", "" ] ]
By utilizing a soft-hard factorized model, which combines a thermal perturbative description of soft scatterings and a perturbative QCD-based calculation for hard collisions, we study the energy and temperature dependence of the heavy quark diffusion coefficients in Langevin dynamics. The adjustable parameters are fixed from the comprehensive model-data comparison. We find that a small value of the spatial diffusion coefficient at transition temperature is preferred by data $2\pi TD_{s}(T_{c}) \simeq 6$. With the parameter-optimized model, we are able to describe simultaneously the prompt $D^{0}$ $R_{\rm AA}$ and $v_{2}$ data at $p_{\rm T}\le8$ GeV in Pb--Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ and $\sqrt{s_{\rm NN}}=5.02$ TeV. We also make predictions for non-prompt $D^{0}$ meson for future experimental tests down to the low momentum region.
1605.03860
Wolfgang Hollik
J. L. D\'iaz-Cruz, W. G. Hollik, and U. J. Salda\~na-Salazar
A bottom-up approach to the strong CP problem
12 pages; v2: extended discussion, title changed to be more general
International Journal of Modern Physics A Vol. 33 (2018) 1850088
10.1142/S0217751X18500884
DESY 16-084
hep-ph
http://creativecommons.org/licenses/by/4.0/
The strong CP problem is one of many puzzles in the theoretical description of elementary particle physics that still lacks an explanation. While top-down solutions to that problem usually comprise new symmetries or fields or both, we want to present a rather bottom-up perspective. The main problem seems to be how to achieve small CP violation in the strong interactions despite large CP violation in weak interactions. Observation of CP violation is exclusively through the Higgs--Yukawa interactions. In this paper, we show that with minimal assumptions on the structure of mass (Yukawa) matrices they do not contribute to the strong CP problem and thus we can provide a pathway to a solution of the strong CP problem within the structures of the Standard Model and no extension at the electroweak scale is needed. However, to address the flavor puzzle, models based on minimal SU(3) flavor groups leading to the proposed flavor matrices are favored. Though we refrain from an explicit a UV completion of the Standard Model, we provide a simple requirement those models should have to intrinsically not show a strong CP problem.
[ { "created": "Thu, 12 May 2016 15:42:25 GMT", "version": "v1" }, { "created": "Mon, 23 Oct 2017 08:37:28 GMT", "version": "v2" } ]
2018-05-17
[ [ "Díaz-Cruz", "J. L.", "" ], [ "Hollik", "W. G.", "" ], [ "Saldaña-Salazar", "U. J.", "" ] ]
The strong CP problem is one of many puzzles in the theoretical description of elementary particle physics that still lacks an explanation. While top-down solutions to that problem usually comprise new symmetries or fields or both, we want to present a rather bottom-up perspective. The main problem seems to be how to achieve small CP violation in the strong interactions despite large CP violation in weak interactions. Observation of CP violation is exclusively through the Higgs--Yukawa interactions. In this paper, we show that with minimal assumptions on the structure of mass (Yukawa) matrices they do not contribute to the strong CP problem and thus we can provide a pathway to a solution of the strong CP problem within the structures of the Standard Model and no extension at the electroweak scale is needed. However, to address the flavor puzzle, models based on minimal SU(3) flavor groups leading to the proposed flavor matrices are favored. Though we refrain from an explicit a UV completion of the Standard Model, we provide a simple requirement those models should have to intrinsically not show a strong CP problem.
2109.01259
Song Mao
Zhuo Yu, Mao Song, Jian-You Guo, Yu Zhang, Gang Li
Probing double hadron resonances by the complex scaling method
7 pages, 6 figures, accepted by Physical Review C
Phys. Rev. C 104, 035201 (2021)
10.1103/PhysRevC.104.035201
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Many newly discovered excited states are interpreted as bound states of hadrons. Can these hadrons also form resonant states? In this paper, we extend the complex scaling method (CSM) to calculate the bound state and resonant state consistently for the $\Lambda_c D(\bar D)$ and $\Lambda_c \Lambda_c (\bar \Lambda_c)$ systems. For these systems, the $\pi, \eta, \rho$ meson exchange contributions are suppressed, the contributions of intermediate- and short-range forces from $\sigma/\omega$ exchange are dominant. Our results indicate that $\Lambda_c D$ system can not form bound state and resonant state. There exist resonant states in a wide range of parameters for $\Lambda_c \bar D$ and $\Lambda_c \Lambda_c (\bar \Lambda_c)$ systems. For these systems, the larger bound state energy, the easier to form resonant states. Among all the resonant states, the energies and widths of the P wave resonant states are smaller and more stable, which is possible to be observed in the experiments. The energies of D and F wave resonant states can reach dozens of MeV and the widths can reach hundreds of MeV.
[ { "created": "Fri, 3 Sep 2021 01:02:31 GMT", "version": "v1" } ]
2021-09-15
[ [ "Yu", "Zhuo", "" ], [ "Song", "Mao", "" ], [ "Guo", "Jian-You", "" ], [ "Zhang", "Yu", "" ], [ "Li", "Gang", "" ] ]
Many newly discovered excited states are interpreted as bound states of hadrons. Can these hadrons also form resonant states? In this paper, we extend the complex scaling method (CSM) to calculate the bound state and resonant state consistently for the $\Lambda_c D(\bar D)$ and $\Lambda_c \Lambda_c (\bar \Lambda_c)$ systems. For these systems, the $\pi, \eta, \rho$ meson exchange contributions are suppressed, the contributions of intermediate- and short-range forces from $\sigma/\omega$ exchange are dominant. Our results indicate that $\Lambda_c D$ system can not form bound state and resonant state. There exist resonant states in a wide range of parameters for $\Lambda_c \bar D$ and $\Lambda_c \Lambda_c (\bar \Lambda_c)$ systems. For these systems, the larger bound state energy, the easier to form resonant states. Among all the resonant states, the energies and widths of the P wave resonant states are smaller and more stable, which is possible to be observed in the experiments. The energies of D and F wave resonant states can reach dozens of MeV and the widths can reach hundreds of MeV.
2107.03203
Zeren Simon Wang
Kingman Cheung, Kechen Wang, Zeren Simon Wang
Time-delayed electrons from neutral currents at the LHC
v1: 13 pages, 13 figures, 1 table; v2: added notes about the history of the timing technique after publication, no change otherwise
null
10.1007/JHEP09(2021)026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate long-lived particles (LLPs) produced in pair from neutral currents and decaying into a displaced electron plus two jets at the LHC, utilizing the proposed minimum ionizing particle timing detector at CMS. We study two benchmark models: the R-parity-violating supersymmetry with the lightest neutralinos being the lightest supersymmetric particle and two different $U(1)$ extensions of the standard model with heavy neutral leptons (HNLs). The light neutralinos are produced from the standard model $Z$-boson decays via small Higgsino components, and the HNLs arise from decays of a heavy gauge boson, $Z'$. By simulating the signal processes at the HL-LHC with the center-of-mass energy $\sqrt{s}=$ 14 TeV and integrated luminosity of 3 ab$^{-1}$, our analyses indicate that the search strategy based on a timing trigger and the final state kinematics has the potential to probe the parameter space that is complementary to other traditional LLP search strategies such as those based on the displaced vertex.
[ { "created": "Wed, 7 Jul 2021 13:19:50 GMT", "version": "v1" }, { "created": "Thu, 18 Nov 2021 12:13:22 GMT", "version": "v2" } ]
2021-11-19
[ [ "Cheung", "Kingman", "" ], [ "Wang", "Kechen", "" ], [ "Wang", "Zeren Simon", "" ] ]
We investigate long-lived particles (LLPs) produced in pair from neutral currents and decaying into a displaced electron plus two jets at the LHC, utilizing the proposed minimum ionizing particle timing detector at CMS. We study two benchmark models: the R-parity-violating supersymmetry with the lightest neutralinos being the lightest supersymmetric particle and two different $U(1)$ extensions of the standard model with heavy neutral leptons (HNLs). The light neutralinos are produced from the standard model $Z$-boson decays via small Higgsino components, and the HNLs arise from decays of a heavy gauge boson, $Z'$. By simulating the signal processes at the HL-LHC with the center-of-mass energy $\sqrt{s}=$ 14 TeV and integrated luminosity of 3 ab$^{-1}$, our analyses indicate that the search strategy based on a timing trigger and the final state kinematics has the potential to probe the parameter space that is complementary to other traditional LLP search strategies such as those based on the displaced vertex.
hep-ph/9405400
Little Peter
K.Golec-Biernat, J.Kwiecinski, A.D.Martin and P.J.Sutton
Transverse Energy Flow at HERA
8 LaTeX pages, 4 figures included as uuencoded postscript at the end of the LaTeX file, Durham preprint DTP/94/30
Phys.Lett.B335:220-225,1994
10.1016/0370-2693(94)91417-6
null
hep-ph
null
We calculate the transverse energy flow accompanying small $x$ deep-inelastic events and compare with recent data obtained at HERA. In the central region between the current jet and the remnants of the proton we find that BFKL leading $\ln(1/x)$ dynamics gives a distinctively large transverse energy distribution, in approximate agreement with recent data.
[ { "created": "Fri, 27 May 1994 17:04:42 GMT", "version": "v1" } ]
2010-03-25
[ [ "Golec-Biernat", "K.", "" ], [ "Kwiecinski", "J.", "" ], [ "Martin", "A. D.", "" ], [ "Sutton", "P. J.", "" ] ]
We calculate the transverse energy flow accompanying small $x$ deep-inelastic events and compare with recent data obtained at HERA. In the central region between the current jet and the remnants of the proton we find that BFKL leading $\ln(1/x)$ dynamics gives a distinctively large transverse energy distribution, in approximate agreement with recent data.
2203.05591
Peter Denton
Roshan Mammen Abraham, Jaime Alvarez-Mu\~niz, Carlos A. Arg\"uelles, Akitaka Ariga, Tomoko Ariga, Adam Aurisano, Dario Autiero, Mary Bishai, Nilay Bostan, Mauricio Bustamante, Austin Cummings, Valentin Decoene, Andr\'e de Gouv\^ea, Giovanni De Lellis, Albert De Roeck, Peter B. Denton, Antonia Di Crescenzo, Milind V. Diwan, Yasaman Farzan, Anatoli Fedynitch, Jonathan L. Feng, Laura J. Fields, Alfonso Garcia, Maria Vittoria Garzelli, Julia Gehrlein, Christian Glaser, Katarzyna Grzelak, Steffen Hallmann, V Hewes, D. Indumathi, Ahmed Ismail, Sudip Jana, Yu Seon Jeong, Kevin J. Kelly, Spencer R. Klein, Felix Kling, Thomas Kosc, Umut Kose, D. Jason Koskinen, John Krizmanic, Jeff Lazar, Yichen Li, Ivan Martinez-Soler, Irina Mocioiu, Jiwoo Nam, Valentin Niess, Nepomuk Otte, Sameer Patel, Roberto Petti, Remy L. Prechelt, Steven Prohira, Miriama Rajaoalisoa, Mary Hall Reno, Ibrahim Safa, Carlos Sarasty-Segura, R. Thiru Senthil, Juliana Stachurska, Oleksandr Tomalak, Sebastian Trojanowski, Roger Alexandre Wendell, Dawn Williams, Stephanie Wissel, Barbara Yaeggy, Enrique Zas, Pavel Zhelnin, Jing-yu Zhu
Tau Neutrinos in the Next Decade: from GeV to EeV
155 pages, 63 figures, 10 tables, 69 endorsers, comments welcome, Contribution to Snowmass 2021. v2: published version
J. Phys. G: Nucl. Part. Phys. 49, 11 (2022)
10.1088/1361-6471/ac89d2
DESY-22-040, LA-UR-21-32255
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tau neutrinos are the least studied particle in the Standard Model. This whitepaper discusses the current and expected upcoming status of tau neutrino physics with attention to the broad experimental and theoretical landscape spanning long-baseline, beam-dump, collider, and astrophysical experiments. This whitepaper was prepared as a part of the NuTau2021 Workshop.
[ { "created": "Thu, 10 Mar 2022 19:07:12 GMT", "version": "v1" }, { "created": "Tue, 11 Oct 2022 22:27:26 GMT", "version": "v2" } ]
2023-02-17
[ [ "Abraham", "Roshan Mammen", "" ], [ "Alvarez-Muñiz", "Jaime", "" ], [ "Argüelles", "Carlos A.", "" ], [ "Ariga", "Akitaka", "" ], [ "Ariga", "Tomoko", "" ], [ "Aurisano", "Adam", "" ], [ "Autiero", "Dario", ...
Tau neutrinos are the least studied particle in the Standard Model. This whitepaper discusses the current and expected upcoming status of tau neutrino physics with attention to the broad experimental and theoretical landscape spanning long-baseline, beam-dump, collider, and astrophysical experiments. This whitepaper was prepared as a part of the NuTau2021 Workshop.
1309.5723
Xing-Gang Wu
Hai-Bing Fu, Xing-Gang Wu, Hua-Yong Han, Yang Ma and Tao Zhong
$V_{cb}$ from the semileptonic decay $B\to D \ell \bar{\nu}_{\ell}$ and the properties of the $D$ meson distribution amplitude
13 pages, 10 figures. Reference updated and discussion improved. To be published in Nucl.Phys.B
Nucl.Phys.B 884 (2014) 172
10.1016/j.nuclphysb.2014.04.021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The improved QCD light-cone sum rule (LCSR) provides an effective way to deal with the heavy-to-light transition form factors (TFFs). Firstly, we adopt the improved LCSR approach to deal with the $B\to D$ TFF $f^{+}(q^2)$ up to twist-4 accuracy. Due to the elimination of the most uncertain twist-3 contribution and the large suppression of the twist-4 contribution, the obtained LCSR shall provide us a good platform for testing the $D$-meson leading-twist DA. For the purpose, we suggest a new model for the $D$-meson leading-twist DA ($\phi_{3D}$), whose longitudinal behavior is dominantly determined by a parameter $B$. Moreover, we find its second Gegenbauer moment $a^D_2\sim B$. Varying $B$ within certain region, one can conveniently mimic the $D$-meson DA behavior suggested in the literature. Inversely, by comparing the estimations with the experimental data on the $D$-meson involved processes, one can get a possible range for the parameter $B$ and a determined behavior for the $D$-meson DA. Secondly, we discuss the $B\to D$ TFF at the maximum recoil region and present a detailed comparison of it with the pQCD estimation and the experimental measurements. Thirdly, by applying the LCSR on $f^{+}(q^2)$, we study the CKM matrix element $\Vcb$ together with its uncertainties by adopting two types of processes, i.e. the $B^0/\bar{B}^0$-type and the $B^{\pm}$-type. It is noted that a smaller $B \precsim 0.20$ shows a better agreement with the experimental value on $\Vcb$. For example, for the case of $B=0.00$, we obtain $|V_{cb}|(B^0/\bar{B}^0-{\rm type})=(41.28 {^{+5.68}_{-4.82}} {^{+1.13}_{-1.16}}) \times 10^{-3}$ and $|V_{cb}|(B^{\pm}-{\rm type})=(40.44 {^{+5.56}_{-4.72}} {^{+0.98}_{-1.00}}) \times 10^{-3}$, whose first (second) uncertainty comes from the squared average of the mentioned theoretical (experimental) uncertainties.
[ { "created": "Mon, 23 Sep 2013 08:08:20 GMT", "version": "v1" }, { "created": "Wed, 25 Sep 2013 09:34:04 GMT", "version": "v2" }, { "created": "Mon, 6 Jan 2014 06:21:38 GMT", "version": "v3" }, { "created": "Sat, 26 Apr 2014 12:26:10 GMT", "version": "v4" } ]
2014-05-15
[ [ "Fu", "Hai-Bing", "" ], [ "Wu", "Xing-Gang", "" ], [ "Han", "Hua-Yong", "" ], [ "Ma", "Yang", "" ], [ "Zhong", "Tao", "" ] ]
The improved QCD light-cone sum rule (LCSR) provides an effective way to deal with the heavy-to-light transition form factors (TFFs). Firstly, we adopt the improved LCSR approach to deal with the $B\to D$ TFF $f^{+}(q^2)$ up to twist-4 accuracy. Due to the elimination of the most uncertain twist-3 contribution and the large suppression of the twist-4 contribution, the obtained LCSR shall provide us a good platform for testing the $D$-meson leading-twist DA. For the purpose, we suggest a new model for the $D$-meson leading-twist DA ($\phi_{3D}$), whose longitudinal behavior is dominantly determined by a parameter $B$. Moreover, we find its second Gegenbauer moment $a^D_2\sim B$. Varying $B$ within certain region, one can conveniently mimic the $D$-meson DA behavior suggested in the literature. Inversely, by comparing the estimations with the experimental data on the $D$-meson involved processes, one can get a possible range for the parameter $B$ and a determined behavior for the $D$-meson DA. Secondly, we discuss the $B\to D$ TFF at the maximum recoil region and present a detailed comparison of it with the pQCD estimation and the experimental measurements. Thirdly, by applying the LCSR on $f^{+}(q^2)$, we study the CKM matrix element $\Vcb$ together with its uncertainties by adopting two types of processes, i.e. the $B^0/\bar{B}^0$-type and the $B^{\pm}$-type. It is noted that a smaller $B \precsim 0.20$ shows a better agreement with the experimental value on $\Vcb$. For example, for the case of $B=0.00$, we obtain $|V_{cb}|(B^0/\bar{B}^0-{\rm type})=(41.28 {^{+5.68}_{-4.82}} {^{+1.13}_{-1.16}}) \times 10^{-3}$ and $|V_{cb}|(B^{\pm}-{\rm type})=(40.44 {^{+5.56}_{-4.72}} {^{+0.98}_{-1.00}}) \times 10^{-3}$, whose first (second) uncertainty comes from the squared average of the mentioned theoretical (experimental) uncertainties.
2211.17187
Jasmina Nasufi
Jasmina Nasufi
$t\bar tZ$ in the $4\ell$ channel at NLO in QCD
Poster at the 15th International Workshop on Top Quark Physics, Durham, UK, 4-9 September 2022
null
null
TTK-22-43,P3H-22-120
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
NLO QCD corrections to the process $pp \rightarrow e^+\nu_e \mu^- \bar{\nu}_{\mu} \tau^+\tau^- b \bar{b}+X$ are presented with the full off-shell effects included. The calculation includes all resonant and non-resonant Feynman diagrams, photon and $Z$-gauge boson contributions, as well as interference effects, all incorporated at the matrix element level. Furthermore all heavy intermediate particles are described via Breit-Wigner propagators. Theoretical uncertainties related to the scale variation and choice of PDF sets were investigated at the integrated and differential level. The modelling is studied by a direct comparison of the full off-shell process to the NWA, where tops, $Z$- and $W$-gauge bosons are on-shell. Moreover, motivated by experimental cuts, we also investigate the impact of imposing a window cut around the mass of the $Z$-gauge boson on the full off-shell predictions.
[ { "created": "Tue, 29 Nov 2022 18:24:09 GMT", "version": "v1" }, { "created": "Mon, 5 Dec 2022 09:24:07 GMT", "version": "v2" } ]
2022-12-06
[ [ "Nasufi", "Jasmina", "" ] ]
NLO QCD corrections to the process $pp \rightarrow e^+\nu_e \mu^- \bar{\nu}_{\mu} \tau^+\tau^- b \bar{b}+X$ are presented with the full off-shell effects included. The calculation includes all resonant and non-resonant Feynman diagrams, photon and $Z$-gauge boson contributions, as well as interference effects, all incorporated at the matrix element level. Furthermore all heavy intermediate particles are described via Breit-Wigner propagators. Theoretical uncertainties related to the scale variation and choice of PDF sets were investigated at the integrated and differential level. The modelling is studied by a direct comparison of the full off-shell process to the NWA, where tops, $Z$- and $W$-gauge bosons are on-shell. Moreover, motivated by experimental cuts, we also investigate the impact of imposing a window cut around the mass of the $Z$-gauge boson on the full off-shell predictions.
hep-ph/9802321
Shi-Lin Zhu
Shi-Lin Zhu(1,2), W.-Y.P.Hwang(3) and Ze-sen Yang(1), ((1) Physics department, Peking Uinversity, (2) Institute of Theoretical Physics, Academia Sinica, (3) Physics department, National Taiwan University)
The possible $\Sigma^0$-$\Lambda$ mixing in QCD sum rules
null
Phys.Rev. D57 (1998) 1524-1526
10.1103/PhysRevD.57.1524
null
hep-ph
null
We calculate the on-shell $\Sigma^0$-$\Lambda$ mixing parameter $\theta$ with the method of QCD sum rule. Our result is $\theta (m^2_{\Sigma^0}) =(-)(0.5\pm 0.1)$MeV. The electromagnetic interaction is not included.
[ { "created": "Sat, 14 Feb 1998 02:26:03 GMT", "version": "v1" } ]
2009-10-31
[ [ "Zhu", "Shi-Lin", "" ], [ "Hwang", "W. -Y. P.", "" ], [ "Yang", "Ze-sen", "" ] ]
We calculate the on-shell $\Sigma^0$-$\Lambda$ mixing parameter $\theta$ with the method of QCD sum rule. Our result is $\theta (m^2_{\Sigma^0}) =(-)(0.5\pm 0.1)$MeV. The electromagnetic interaction is not included.
hep-ph/0002069
Andre Gusso
Andr\'e Gusso
Can Four-fermion Contact Interactions at One-loop Explain the New Atomic Parity Violation Results?
15 pages, 2 figures
Eur.Phys.J.C17:107-111,2000
10.1007/s100520000453
IFT--P.012/2000
hep-ph
null
We investigate the possibility that four-fermion contact interactions give rise to the observed deviation from the Standard Model prediction for the weak charge of Cesium, through one-loop contributions. We show that the presence of loops involving the third generation quarks can explain such deviation.
[ { "created": "Mon, 7 Feb 2000 15:32:18 GMT", "version": "v1" } ]
2011-09-13
[ [ "Gusso", "André", "" ] ]
We investigate the possibility that four-fermion contact interactions give rise to the observed deviation from the Standard Model prediction for the weak charge of Cesium, through one-loop contributions. We show that the presence of loops involving the third generation quarks can explain such deviation.
hep-ph/0005221
Carl R. Schmidt
James Amundson, Carl Schmidt, Wu-Ki Tung, and Xiaoning Wang
Charm Production in Deep Inelastic Scattering from Threshold to High $Q^{2}
22 pages (LATEX), 8 figures (EPS); A few clarifying changes made; version published in JHEP
JHEP 0010:031,2000
10.1088/1126-6708/2000/10/031
MSU-HEP-70824, CTEQ724, Fermilab-Pub-00/105-T
hep-ph
null
Charm final states in deep inelastic scattering constitute $\sim 25%$ of the inclusive cross-section at small $x$ as measured at HERA. These data can reveal important information on the charm and gluon structure of the nucleon if they are interpreted in a consistent perturbative QCD framework which is valid over the entire energy range from threshold to the high energy limit. We describe in detail how this can be carried out order-by-order in PQCD in the generalized \msbar formalism of Collins (generally known as the ACOT approach), and demonstrate the inherent smooth transition from the 3-flavor to the 4-flavor scheme in a complete order $\alpha_s$ calculation, using a Monte Carlo implementation of this formalism. This calculation is accurate to the same order as the conventional NLO $F_2$ calculation in the limit $\frac{Q}{m_c} >> 1$. It includes the resummed large logarithm contributions of the 3-flavor scheme (generally known in this context as the fixed-flavor-number or FFN scheme) to all orders of $\alpha_s\ln(m_c^2/Q^2)$. For the inclusive structure function, comparison with recent HERA data and the existing FFN calculation reveals that the relatively simple order-$\alpha_s$ (NLO) 4-flavor ($m_c \neq 0$) calculation can, in practice, be extended to rather low energy scales, yielding good agreement with data over the full measured $Q^2$ range. The Monte Carlo implementation also allows the calculation of differential distributions with relevant kinematic cuts. Comparisons with available HERA data show qualitative agreement; however, they also indicate the need to extend the calculation to the next order to obtain better description of the differential distributions.
[ { "created": "Mon, 22 May 2000 16:53:59 GMT", "version": "v1" }, { "created": "Mon, 10 Jul 2000 12:51:52 GMT", "version": "v2" }, { "created": "Wed, 8 Nov 2000 20:18:16 GMT", "version": "v3" } ]
2009-10-31
[ [ "Amundson", "James", "" ], [ "Schmidt", "Carl", "" ], [ "Tung", "Wu-Ki", "" ], [ "Wang", "Xiaoning", "" ] ]
Charm final states in deep inelastic scattering constitute $\sim 25%$ of the inclusive cross-section at small $x$ as measured at HERA. These data can reveal important information on the charm and gluon structure of the nucleon if they are interpreted in a consistent perturbative QCD framework which is valid over the entire energy range from threshold to the high energy limit. We describe in detail how this can be carried out order-by-order in PQCD in the generalized \msbar formalism of Collins (generally known as the ACOT approach), and demonstrate the inherent smooth transition from the 3-flavor to the 4-flavor scheme in a complete order $\alpha_s$ calculation, using a Monte Carlo implementation of this formalism. This calculation is accurate to the same order as the conventional NLO $F_2$ calculation in the limit $\frac{Q}{m_c} >> 1$. It includes the resummed large logarithm contributions of the 3-flavor scheme (generally known in this context as the fixed-flavor-number or FFN scheme) to all orders of $\alpha_s\ln(m_c^2/Q^2)$. For the inclusive structure function, comparison with recent HERA data and the existing FFN calculation reveals that the relatively simple order-$\alpha_s$ (NLO) 4-flavor ($m_c \neq 0$) calculation can, in practice, be extended to rather low energy scales, yielding good agreement with data over the full measured $Q^2$ range. The Monte Carlo implementation also allows the calculation of differential distributions with relevant kinematic cuts. Comparisons with available HERA data show qualitative agreement; however, they also indicate the need to extend the calculation to the next order to obtain better description of the differential distributions.
1208.4304
Yakov Azimov
Ya. Azimov
What is the real meaning of the Froissart theorem ?
7 pages, 1 figure, LATEX, uses hsqcd.cls (included); plenary talk at the International Workshop HSQCD 2012, St.Petersburg, Russia, 4--8 July, 2012; to appear in Proceedings. v2: small corrections, mainly in bibliography
Published in the Proceedings of the International Workshop HSQCD 2012, eds. V.T.Kim and L.N.Lipatov (PNPI, Gatchina, 2012) p.22
null
null
hep-ph hep-ex hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Froissart bounds for amplitudes and cross sections are explained and reconsidered to clarify the role of different assumptions. It is the physical conditions of unitarity and of no massless exchanges, together with mathematical properties of the Legendre functions, that imply much softer high-energy asymptotics for elastic amplitudes at physical angles than for the same amplitudes at nonphysical angles. The canonical log-squared boundary for \sigma_{tot} appears only under the additional hypothesis that the amplitude at any nonphysical angle cannot grow faster than some power of energy. The Froissart results are further shown to admit some reinforcement. Comparison of the familiar and new Froissart-like restrictions with the existing data on \sigma_{tot} and diffraction slope at all available energies (including LHC) does not allow yet to unambiguously determine the asymptotic behavior of \sigma_{tot}, but shows that its current increase cannot be saturated (i.e., maximally rapid).
[ { "created": "Tue, 21 Aug 2012 17:04:08 GMT", "version": "v1" }, { "created": "Mon, 1 Jul 2013 18:11:57 GMT", "version": "v2" } ]
2014-01-03
[ [ "Azimov", "Ya.", "" ] ]
The Froissart bounds for amplitudes and cross sections are explained and reconsidered to clarify the role of different assumptions. It is the physical conditions of unitarity and of no massless exchanges, together with mathematical properties of the Legendre functions, that imply much softer high-energy asymptotics for elastic amplitudes at physical angles than for the same amplitudes at nonphysical angles. The canonical log-squared boundary for \sigma_{tot} appears only under the additional hypothesis that the amplitude at any nonphysical angle cannot grow faster than some power of energy. The Froissart results are further shown to admit some reinforcement. Comparison of the familiar and new Froissart-like restrictions with the existing data on \sigma_{tot} and diffraction slope at all available energies (including LHC) does not allow yet to unambiguously determine the asymptotic behavior of \sigma_{tot}, but shows that its current increase cannot be saturated (i.e., maximally rapid).
1601.04654
Per Osland
D. Emmanuel-Costa, O. M. Ogreid, P. Osland, M. N. Rebelo
Spontaneous symmetry breaking in the $S_3$-symmetric scalar sector
37 pages. v2: Minor changes in the references, matches published version. v3: Table 6 corrected: two additional cases conserve CP. Related discussion adapted. Version consistent with JHEP Erratum
null
10.1007/JHEP02(2016)154
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a detailed study of the vacua of the $S_3$-symmetric three-Higgs-doublet potential, specifying the region of parameters where these minimisation solutions occur. We work with a CP conserving scalar potential and analyse the possible real and complex vacua with emphasis on the cases in which the CP symmetry can be spontaneously broken. Results are presented both in the reducible-representation framework of Derman, and in the irreducible-representation framework. Mappings between these are given. Some of these implementations can in principle accommodate dark matter and for that purpose it is important to identify the residual symmetries of the potential after spontaneous symmetry breakdown. We are also concerned with constraints from vacuum stability.
[ { "created": "Mon, 18 Jan 2016 18:55:30 GMT", "version": "v1" }, { "created": "Tue, 1 Mar 2016 15:05:47 GMT", "version": "v2" }, { "created": "Sun, 11 Sep 2016 15:01:38 GMT", "version": "v3" } ]
2016-09-13
[ [ "Emmanuel-Costa", "D.", "" ], [ "Ogreid", "O. M.", "" ], [ "Osland", "P.", "" ], [ "Rebelo", "M. N.", "" ] ]
We present a detailed study of the vacua of the $S_3$-symmetric three-Higgs-doublet potential, specifying the region of parameters where these minimisation solutions occur. We work with a CP conserving scalar potential and analyse the possible real and complex vacua with emphasis on the cases in which the CP symmetry can be spontaneously broken. Results are presented both in the reducible-representation framework of Derman, and in the irreducible-representation framework. Mappings between these are given. Some of these implementations can in principle accommodate dark matter and for that purpose it is important to identify the residual symmetries of the potential after spontaneous symmetry breakdown. We are also concerned with constraints from vacuum stability.
1012.1052
Amol Dighe
Biplob Bhattacherjee, Amol Dighe, Diptimoy Ghosh, Sreerup Raychaudhuri (Tata Inst.)
Do new data on [B+ -> tau+ nu_tau] decays point to an early discovery of supersymmetry at the LHC?
31 pages, 6 eps figures, revtex4.1. Final version to be published in PRD. (Minor changes from the first version)
Phys.Rev.D83:094026,2011
10.1103/PhysRevD.83.094026
TIFR-TH/10-35
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent Belle and BaBar measurements of the branching ratio of $B^+ \to \tau^+ \nu_\tau$ indicate a significant deviation from the Standard Model prediction. We demonstrate that this measurement has a serious impact on models with minimal flavor violation involving a charged Higgs boson, ruling out a large portion of the currently-allowed parameter space. In the constrained minimal supersymmetric standard model, this creates a tension between the measurements of $B^+ \to \tau^+ \nu_\tau$ and the anomalous magnetic moment of the muon, unless $\tan\beta$ is small, $\mu > 0$, and $A_0$ takes a large negative value. In fact, a very small region of the parameter space of this model, with small values of $m_0$ and $m_{1/2}$, survives all the constraints at 95% C.L.. It is remarkable that this specific region is still consistent with the lightest supersymmetric particle as the dark matter. Moreover, it predicts observable SUSY signals in the early runs of the LHC, even perhaps at 7 TeV. We also show that a consistent explanation for the deviation of the $B^+ \to \tau^+ \nu_\tau$ branching ratio from the Standard Model can be achieved in a non-universal Higgs mass model, which could also predict early signals of supersymmetry at the LHC.
[ { "created": "Sun, 5 Dec 2010 23:28:16 GMT", "version": "v1" }, { "created": "Mon, 16 May 2011 11:36:55 GMT", "version": "v2" } ]
2015-03-17
[ [ "Bhattacherjee", "Biplob", "", "Tata Inst." ], [ "Dighe", "Amol", "", "Tata Inst." ], [ "Ghosh", "Diptimoy", "", "Tata Inst." ], [ "Raychaudhuri", "Sreerup", "", "Tata Inst." ] ]
The recent Belle and BaBar measurements of the branching ratio of $B^+ \to \tau^+ \nu_\tau$ indicate a significant deviation from the Standard Model prediction. We demonstrate that this measurement has a serious impact on models with minimal flavor violation involving a charged Higgs boson, ruling out a large portion of the currently-allowed parameter space. In the constrained minimal supersymmetric standard model, this creates a tension between the measurements of $B^+ \to \tau^+ \nu_\tau$ and the anomalous magnetic moment of the muon, unless $\tan\beta$ is small, $\mu > 0$, and $A_0$ takes a large negative value. In fact, a very small region of the parameter space of this model, with small values of $m_0$ and $m_{1/2}$, survives all the constraints at 95% C.L.. It is remarkable that this specific region is still consistent with the lightest supersymmetric particle as the dark matter. Moreover, it predicts observable SUSY signals in the early runs of the LHC, even perhaps at 7 TeV. We also show that a consistent explanation for the deviation of the $B^+ \to \tau^+ \nu_\tau$ branching ratio from the Standard Model can be achieved in a non-universal Higgs mass model, which could also predict early signals of supersymmetry at the LHC.
1204.5974
Vladimir Smolyar
V.D. Rusov, V.A. Tarasov, S.A. Chernegenko, V.P. Smolyar
Comment on "Observation of electron-antineutrino disappearance at Daya Bay"
2 pages, 1 figure (v2: a misprint in equation (1) corrected)
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent Letter by An et al. [arXiv:1203.1669] Daya Bay measurements of non-zero value for the neutrino mixing angle {\theta}_{13} with a significance of 5.2 standard deviations were reported. The value of sin^2 {\theta}_{13} was determined with a {\chi}^2 constructed with pull terms accounting for the correlation of the systematic errors. We show that a direct applying of the KamLAND parameters of mixing to Daya Bay-experiment under nonequilibrium geoneutrino spectrum of the nuclear burning process within the framework of nonzero nuclear georeactor {\chi}^2 -hypothesis will produce a high uncertainty level and, as a result, a substantial distortion of the actual value of the neutrino mixing angle {\theta}_{13}.
[ { "created": "Thu, 26 Apr 2012 16:26:26 GMT", "version": "v1" }, { "created": "Sat, 28 Apr 2012 10:00:47 GMT", "version": "v2" } ]
2012-05-01
[ [ "Rusov", "V. D.", "" ], [ "Tarasov", "V. A.", "" ], [ "Chernegenko", "S. A.", "" ], [ "Smolyar", "V. P.", "" ] ]
In recent Letter by An et al. [arXiv:1203.1669] Daya Bay measurements of non-zero value for the neutrino mixing angle {\theta}_{13} with a significance of 5.2 standard deviations were reported. The value of sin^2 {\theta}_{13} was determined with a {\chi}^2 constructed with pull terms accounting for the correlation of the systematic errors. We show that a direct applying of the KamLAND parameters of mixing to Daya Bay-experiment under nonequilibrium geoneutrino spectrum of the nuclear burning process within the framework of nonzero nuclear georeactor {\chi}^2 -hypothesis will produce a high uncertainty level and, as a result, a substantial distortion of the actual value of the neutrino mixing angle {\theta}_{13}.
hep-ph/0009165
Grzegorz Wilk
F.S.Navarra, O.V.Utyuzh, Z.Wlodarczyk and G.Wilk
Violation of the Feynman scaling law as a manifestation of nonextensivity
gz-compressed .tar file containing LaTeX file and 3 PS files with figures (and 2 PS files with figure captions), 5 pages altogether (Nuovo Cimento cimento.cls style file attached) Presented at Chacaltaya Meeting On Cosmic Ray Physics, La Paz - Bolivia, 23-27 July 2000. To be published in Nuovo Cimento (Proc. Suppl.)
Nuovo Cim.C24:725-730,2001
null
null
hep-ph
null
We demonstrate that the apparently ad hoc parametrization of the particle production spectra discussed in the literature and used in description of cosmic ray data can be derived from the information theory approach to multiparticle production processes. In particular, the violation of the Feynman scaling law can be interpreted as a manifestation of nonextensivity of the production processes.
[ { "created": "Thu, 14 Sep 2000 08:54:56 GMT", "version": "v1" } ]
2010-11-11
[ [ "Navarra", "F. S.", "" ], [ "Utyuzh", "O. V.", "" ], [ "Wlodarczyk", "Z.", "" ], [ "Wilk", "G.", "" ] ]
We demonstrate that the apparently ad hoc parametrization of the particle production spectra discussed in the literature and used in description of cosmic ray data can be derived from the information theory approach to multiparticle production processes. In particular, the violation of the Feynman scaling law can be interpreted as a manifestation of nonextensivity of the production processes.
1611.04785
German F. R. Sborlini
German F. R. Sborlini, Daniel de Florian, German Rodrigo
Mixed QCD-QED corrections to DGLAP equations
4 pages, 1 figure. Contribution to the Proceedings of the ICHEP 2016 Conference
PoS(ICHEP2016)793
null
IFIC/16-79
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the mixed effect of QCD and QED corrections to the evolution of parton distribution functions (PDFs). The Altarelli-Parisi splitting functions are extended to one order higher in QED, reaching ${\cal O}(\alpha \, \alpha_S^2)$ accuracy. This also involves extending DGLAP equations to include charge separation effects, that are ignored for pure QCD corrections. Besides that, these effects are crucial for the determination of the photon distribution, which plays an increasingly important role in nowadays phenomenological analysis.
[ { "created": "Tue, 15 Nov 2016 10:51:50 GMT", "version": "v1" } ]
2016-11-16
[ [ "Sborlini", "German F. R.", "" ], [ "de Florian", "Daniel", "" ], [ "Rodrigo", "German", "" ] ]
We study the mixed effect of QCD and QED corrections to the evolution of parton distribution functions (PDFs). The Altarelli-Parisi splitting functions are extended to one order higher in QED, reaching ${\cal O}(\alpha \, \alpha_S^2)$ accuracy. This also involves extending DGLAP equations to include charge separation effects, that are ignored for pure QCD corrections. Besides that, these effects are crucial for the determination of the photon distribution, which plays an increasingly important role in nowadays phenomenological analysis.
2006.06602
Peter Schweitzer
Mira Varma, Peter Schweitzer
Effects of long-range forces on the D-term and the energy-momentum structure
null
Phys. Rev. D 102, 014047 (2020)
10.1103/PhysRevD.102.014047
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hadronic form factors of the energy-momentum tensor (EMT) have attracted considerable interest in recent literature. This concerns especially the D-term form factor D(t) with its appealing interpretation in terms of internal forces. With their focus on hadron structure, theoretical studies so far have concentrated on strongly interacting systems with short-range forces. Effects on the EMT due to long-range forces like the electromagnetic interaction have not yet been studied. Electromagnetic forces play a small role in the balance of forces inside the proton, but their long-range nature introduces new features which are not present in systems with short-range forces. We use a simple but consistent classical field theoretical model of the proton to show how the presence of long-range forces alters some notions taken for granted in short-range systems. Our results imply that a more careful definition of the D-term is required when long-range forces are present.
[ { "created": "Thu, 11 Jun 2020 16:53:15 GMT", "version": "v1" } ]
2020-08-05
[ [ "Varma", "Mira", "" ], [ "Schweitzer", "Peter", "" ] ]
The hadronic form factors of the energy-momentum tensor (EMT) have attracted considerable interest in recent literature. This concerns especially the D-term form factor D(t) with its appealing interpretation in terms of internal forces. With their focus on hadron structure, theoretical studies so far have concentrated on strongly interacting systems with short-range forces. Effects on the EMT due to long-range forces like the electromagnetic interaction have not yet been studied. Electromagnetic forces play a small role in the balance of forces inside the proton, but their long-range nature introduces new features which are not present in systems with short-range forces. We use a simple but consistent classical field theoretical model of the proton to show how the presence of long-range forces alters some notions taken for granted in short-range systems. Our results imply that a more careful definition of the D-term is required when long-range forces are present.
1812.02991
Andreas Helset
Andreas Helset and Michael Trott
Equations of motion, symmetry currents and EFT below the electroweak scale
13 pages
null
10.1016/j.physletb.2019.06.070
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The low-energy effective field theory is constructed by integrating out Standard Model states with masses proximate to the electroweak scale. We report the equations of motion for this theory, including corrections due to higher dimensional operators up to mass dimension six. We construct the corresponding symmetry currents, and discuss how the $\rm SU(2)_L \times U(1)_{\mathsf{y}}$ symmetry, and global symmetries, are manifested when Standard Model states are integrated out. Including contributions from higher dimensional operators to the equations of motion modifies the interpretation of conserved currents. We discuss the corrections to the electromagnetic current as an example, showing how modifications to the equation of motion, and corresponding surface terms, have a direct interpretation in terms of multipole charge distributions that act to source gauge fields.
[ { "created": "Fri, 7 Dec 2018 12:05:06 GMT", "version": "v1" } ]
2019-07-10
[ [ "Helset", "Andreas", "" ], [ "Trott", "Michael", "" ] ]
The low-energy effective field theory is constructed by integrating out Standard Model states with masses proximate to the electroweak scale. We report the equations of motion for this theory, including corrections due to higher dimensional operators up to mass dimension six. We construct the corresponding symmetry currents, and discuss how the $\rm SU(2)_L \times U(1)_{\mathsf{y}}$ symmetry, and global symmetries, are manifested when Standard Model states are integrated out. Including contributions from higher dimensional operators to the equations of motion modifies the interpretation of conserved currents. We discuss the corrections to the electromagnetic current as an example, showing how modifications to the equation of motion, and corresponding surface terms, have a direct interpretation in terms of multipole charge distributions that act to source gauge fields.
1812.08673
Antonino Di Piazza
T. Podszus and A. Di Piazza
High-energy behavior of strong-field QED in an intense plane wave
29 pages, 4 figures
Phys. Rev. D 99, 076004 (2019)
10.1103/PhysRevD.99.076004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Analytical calculations of radiative corrections in strong-field QED have hinted that in the presence of an intense plane wave the effective coupling of the theory in the high-energy sector may increase as the $(2/3)$-power of the energy scale. These findings have raised the question of their compatibility with the corresponding logarithmic increase of radiative corrections in QED in vacuum. However, all these analytical results in strong-field QED have been obtained within the limiting case of a background constant crossed field. Starting from the polarization operator and the mass operator in a general plane wave, we show that the constant-crossed-field limit and the high-energy limit do not commute with each other and identify the physical parameter discriminating between the two alternative limits orders. As a result, we find that the power-law scaling at asymptotically large energy scales pertains strictly speaking only to the case of a constant crossed background field, whereas high-energy radiative corrections in a general plane wave depend logarithmically on the energy scale as in vacuum. However, we also confirm the possibility of testing the ``power-law'' regime experimentally by means of realistic setups involving, e.g., high-power lasers or high-density electron-positron bunches.
[ { "created": "Thu, 20 Dec 2018 16:22:38 GMT", "version": "v1" }, { "created": "Sat, 6 Apr 2019 06:21:43 GMT", "version": "v2" } ]
2019-04-10
[ [ "Podszus", "T.", "" ], [ "Di Piazza", "A.", "" ] ]
Analytical calculations of radiative corrections in strong-field QED have hinted that in the presence of an intense plane wave the effective coupling of the theory in the high-energy sector may increase as the $(2/3)$-power of the energy scale. These findings have raised the question of their compatibility with the corresponding logarithmic increase of radiative corrections in QED in vacuum. However, all these analytical results in strong-field QED have been obtained within the limiting case of a background constant crossed field. Starting from the polarization operator and the mass operator in a general plane wave, we show that the constant-crossed-field limit and the high-energy limit do not commute with each other and identify the physical parameter discriminating between the two alternative limits orders. As a result, we find that the power-law scaling at asymptotically large energy scales pertains strictly speaking only to the case of a constant crossed background field, whereas high-energy radiative corrections in a general plane wave depend logarithmically on the energy scale as in vacuum. However, we also confirm the possibility of testing the ``power-law'' regime experimentally by means of realistic setups involving, e.g., high-power lasers or high-density electron-positron bunches.
2102.02447
Chuan-Yang Xing
Chuan-Yang Xing, Shou-Hua Zhu
Dark Matter Freeze-out via Catalyzed Annihilation
7 pages, 4 figures. v2: to appear in PRL
Phys. Rev. Lett. 127, 061101 (2021)
10.1103/PhysRevLett.127.061101
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a new paradigm of dark matter freeze-out, where the annihilation of dark matter particles is catalyzed. We discuss in detail the regime that the depletion of dark matter proceeds via $2\chi \to 2A'$ and $3A' \to 2\chi$ processes, in which $\chi$ and $A'$ denote dark matter and the catalyst respectively. In this regime, the dark matter number density is depleted polynomially rather than exponentially (Boltzmann suppression) as in classic WIMPs and SIMPs. The paradigm applies for a secluded weakly interacting dark sector with a dark matter in the $\text{MeV-TeV}$ mass range. The catalyzed annihilation paradigm is compatible with CMB and BBN constraints, with enhanced indirect detection signals.
[ { "created": "Thu, 4 Feb 2021 07:13:14 GMT", "version": "v1" }, { "created": "Sat, 17 Jul 2021 07:19:14 GMT", "version": "v2" } ]
2021-08-11
[ [ "Xing", "Chuan-Yang", "" ], [ "Zhu", "Shou-Hua", "" ] ]
We present a new paradigm of dark matter freeze-out, where the annihilation of dark matter particles is catalyzed. We discuss in detail the regime that the depletion of dark matter proceeds via $2\chi \to 2A'$ and $3A' \to 2\chi$ processes, in which $\chi$ and $A'$ denote dark matter and the catalyst respectively. In this regime, the dark matter number density is depleted polynomially rather than exponentially (Boltzmann suppression) as in classic WIMPs and SIMPs. The paradigm applies for a secluded weakly interacting dark sector with a dark matter in the $\text{MeV-TeV}$ mass range. The catalyzed annihilation paradigm is compatible with CMB and BBN constraints, with enhanced indirect detection signals.
1610.09973
Tamas Biro S
T.S.Biro, A.Jakovac, Z.Schram
Nuclear and Quark Matter at High Temperature
Review intended for EPJ A Topical Issue
EPJ A (Hadrons and Nuclei) 53 (2017) 52
10.1140/epja/i2017-12235-4
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review important ideas on nuclear and quark matter description on the basis of high- temperature field theory concepts, like resummation, dimensional reduction, interaction scale separation and spectral function modification in media. Statistical and thermodynamical concepts are spotted in the light of these methods concentrating on the - partially still open - problems of the hadronization process.
[ { "created": "Mon, 31 Oct 2016 15:33:49 GMT", "version": "v1" } ]
2017-12-01
[ [ "Biro", "T. S.", "" ], [ "Jakovac", "A.", "" ], [ "Schram", "Z.", "" ] ]
We review important ideas on nuclear and quark matter description on the basis of high- temperature field theory concepts, like resummation, dimensional reduction, interaction scale separation and spectral function modification in media. Statistical and thermodynamical concepts are spotted in the light of these methods concentrating on the - partially still open - problems of the hadronization process.
hep-ph/9512206
Vladimir Anisovich
V.V.Anisovich (Petersburg Nuclear Physics Institute, Russia)
Resonance $f_0(1500)$: Is it a scalar glueball ?
LaTex, 8 pages, 2 .eps figures in one uuencoded file, uses epsfig
Phys.Lett. B364 (1995) 195-198
10.1016/0370-2693(95)01396-2
null
hep-ph
null
The ratios of partial widths for the decay of a glueball into two pseudoscalar mesons are calculated under the assumption that the production of light quark pairs ($u\bar u,d\bar d,s\bar s$) in soft gluon-\-induced reactions goes on within universal symmetry breaking. Parameter of the violation of flavour symmetry is fixed by the central hadron production data in high energy hadron collisions and/or by the ratios of radiative decay amplitudes $J/\Psi \to \gamma\eta/\gamma\eta'$ and $J/\Psi \to \gamma \phi \phi/\gamma \omega \omega$. The ratios of coupling constants $glueball\to\pi\pi,K\bar K, \eta\eta,\eta\eta'$ which are calculated with this parameter coincide reasonably with those of $f_0(1500)$, supporting an idea about glueball nature of $f_0(1500)$.
[ { "created": "Fri, 1 Dec 1995 14:57:15 GMT", "version": "v1" } ]
2009-10-28
[ [ "Anisovich", "V. V.", "", "Petersburg Nuclear Physics Institute, Russia" ] ]
The ratios of partial widths for the decay of a glueball into two pseudoscalar mesons are calculated under the assumption that the production of light quark pairs ($u\bar u,d\bar d,s\bar s$) in soft gluon-\-induced reactions goes on within universal symmetry breaking. Parameter of the violation of flavour symmetry is fixed by the central hadron production data in high energy hadron collisions and/or by the ratios of radiative decay amplitudes $J/\Psi \to \gamma\eta/\gamma\eta'$ and $J/\Psi \to \gamma \phi \phi/\gamma \omega \omega$. The ratios of coupling constants $glueball\to\pi\pi,K\bar K, \eta\eta,\eta\eta'$ which are calculated with this parameter coincide reasonably with those of $f_0(1500)$, supporting an idea about glueball nature of $f_0(1500)$.
1711.04534
Jennifer Rittenhouse West
Jennifer Rittenhouse West
Millicharged Scalar Fields, Massive Photons and the Breaking of $SU(3)_{C} \times U(1)_{\rm EM}$
7 pages. Version accepted for publication in PRD
Phys. Rev. D 99, 073009 (2019)
10.1103/PhysRevD.99.073009
UCI-HEP-TR-2017-15
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Under the assumption that the current epoch of the Universe is not special, i.e. is not the final state of a long history of processes in particle physics, the cosmological fate of $SU(3)_C \times U(1)_{\rm EM}$ is investigated. Spontaneous symmetry breaking of $U(1)_{\rm EM}$ at the temperature of the Universe today is carried out. The charged scalar field $\phi_{\rm EM}$ which breaks the symmetry is found to be ruled out for the charge of the electron, $q=e$. Scalar fields with millicharges are viable and limits on their masses and charges are found to be $q\lesssim10^{-3}e$ and $m_{\phi_{\rm EM}}\lesssim10^{-5} \rm eV$. Furthermore, it is possible that $U(1)_{\rm EM}$ has already been broken at temperatures higher than $T=2.7K$ given the nonzero limits on the mass of the photon. A photon mass of $m_{\gamma}=10^{-18} \rm eV$, the current upper limit, is found to require a spontaneously symmetry breaking scalar mass of $m_{\phi_{\rm EM}}\sim 10^{-13} \rm eV$ with charge $q=10^{-6}e$, well within the allowed parameter space of the model. Finally, the cosmological fate of the strong interaction is studied. $SU(3)_C$ is tested for complementarity in which the confinement phase of QCD $+$ colored scalars is equivalent to a spontaneously broken $SU(3)$ gauge theory. If complementarity is not applicable, $SU(3)_C$ has multiple symmetry breaking paths with various final symmetry structures. The stability of the colored vacuum at finite temperature in this scenario is nonperturbative and a definitive statement on the fate of $SU(3)_C$ is left open. Cosmological implications for the metastability of the vacua - electromagnetic, color and electroweak - are discussed.
[ { "created": "Mon, 13 Nov 2017 11:42:02 GMT", "version": "v1" }, { "created": "Thu, 30 Nov 2017 05:23:43 GMT", "version": "v2" }, { "created": "Thu, 14 Mar 2019 06:34:33 GMT", "version": "v3" }, { "created": "Tue, 9 Apr 2019 03:51:33 GMT", "version": "v4" } ]
2019-05-08
[ [ "West", "Jennifer Rittenhouse", "" ] ]
Under the assumption that the current epoch of the Universe is not special, i.e. is not the final state of a long history of processes in particle physics, the cosmological fate of $SU(3)_C \times U(1)_{\rm EM}$ is investigated. Spontaneous symmetry breaking of $U(1)_{\rm EM}$ at the temperature of the Universe today is carried out. The charged scalar field $\phi_{\rm EM}$ which breaks the symmetry is found to be ruled out for the charge of the electron, $q=e$. Scalar fields with millicharges are viable and limits on their masses and charges are found to be $q\lesssim10^{-3}e$ and $m_{\phi_{\rm EM}}\lesssim10^{-5} \rm eV$. Furthermore, it is possible that $U(1)_{\rm EM}$ has already been broken at temperatures higher than $T=2.7K$ given the nonzero limits on the mass of the photon. A photon mass of $m_{\gamma}=10^{-18} \rm eV$, the current upper limit, is found to require a spontaneously symmetry breaking scalar mass of $m_{\phi_{\rm EM}}\sim 10^{-13} \rm eV$ with charge $q=10^{-6}e$, well within the allowed parameter space of the model. Finally, the cosmological fate of the strong interaction is studied. $SU(3)_C$ is tested for complementarity in which the confinement phase of QCD $+$ colored scalars is equivalent to a spontaneously broken $SU(3)$ gauge theory. If complementarity is not applicable, $SU(3)_C$ has multiple symmetry breaking paths with various final symmetry structures. The stability of the colored vacuum at finite temperature in this scenario is nonperturbative and a definitive statement on the fate of $SU(3)_C$ is left open. Cosmological implications for the metastability of the vacua - electromagnetic, color and electroweak - are discussed.
2304.06663
Ken Mimasu
John Ellis, Ken Mimasu and Francesca Zampedri
Dimension-8 SMEFT Analysis of Minimal Scalar Field Extensions of the Standard Model
66 Pages, 14 Figures, 4 Tables
null
null
KCL-PH-TH/2023-18, CERN-TH-2023-038
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the constraints obtainable from present data using the Standard Model Effective Field Theory (SMEFT) on extensions of the Standard Model with additional electroweak singlet or triplet scalar fields. We compare results obtained using only contributions that are linear in dimension-6 operator coefficients with those obtained including terms quadratic in these coefficients as well as contributions that are linear in dimension-8 operator coefficients. We also implement theoretical constraints arising from the stability of the electroweak vacuum and perturbative unitarity. Analyzing the models at the dimension-8 level constrains scalar couplings that are not bounded at the dimension-6 level. The strongest experimental constraints on the singlet model are provided by Higgs coupling measurements, whereas electroweak precision observables provide the strongest constraints on the triplet model. In the singlet model the present di-Higgs constraints already play a significant role. We find that the current constraints on model parameters are already competitive with those anticipated from future di- and tri-Higgs measurements. We compare our results with calculations in the full model, exhibiting the improvements when higher-order SMEFT terms are included. We also identify regions in parameter space where the SMEFT approximation appears to break down. We find that the combination of current constraints with the theoretical bounds still admits regions where the SMEFT approach is not valid, particularly for lower scalar boson masses.
[ { "created": "Thu, 13 Apr 2023 16:51:11 GMT", "version": "v1" } ]
2023-04-14
[ [ "Ellis", "John", "" ], [ "Mimasu", "Ken", "" ], [ "Zampedri", "Francesca", "" ] ]
We analyze the constraints obtainable from present data using the Standard Model Effective Field Theory (SMEFT) on extensions of the Standard Model with additional electroweak singlet or triplet scalar fields. We compare results obtained using only contributions that are linear in dimension-6 operator coefficients with those obtained including terms quadratic in these coefficients as well as contributions that are linear in dimension-8 operator coefficients. We also implement theoretical constraints arising from the stability of the electroweak vacuum and perturbative unitarity. Analyzing the models at the dimension-8 level constrains scalar couplings that are not bounded at the dimension-6 level. The strongest experimental constraints on the singlet model are provided by Higgs coupling measurements, whereas electroweak precision observables provide the strongest constraints on the triplet model. In the singlet model the present di-Higgs constraints already play a significant role. We find that the current constraints on model parameters are already competitive with those anticipated from future di- and tri-Higgs measurements. We compare our results with calculations in the full model, exhibiting the improvements when higher-order SMEFT terms are included. We also identify regions in parameter space where the SMEFT approximation appears to break down. We find that the combination of current constraints with the theoretical bounds still admits regions where the SMEFT approach is not valid, particularly for lower scalar boson masses.
1409.8290
Mikhail Solon
Richard J. Hill and Mikhail P. Solon
Standard Model anatomy of WIMP dark matter direct detection II: QCD analysis and hadronic matrix elements
49 pages, 2 figures
Phys. Rev. D 91, 043505 (2015)
10.1103/PhysRevD.91.043505
EFI Preprint 14-25
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Models of Weakly Interacting Massive Particles (WIMPs) specified at the electroweak scale are systematically matched to effective theories at hadronic scales where WIMP-nucleus scattering observables are evaluated. Anomalous dimensions and heavy quark threshold matching conditions are computed for the complete basis of lowest-dimension effective operators involving quarks and gluons. The resulting QCD renormalization group evolution equations are solved. The status of relevant hadronic matrix elements is reviewed and phenomenological illustrations are given, including details for the computation of the universal limit of nucleon scattering with heavy $SU(2)_W\times U(1)_Y$ charged WIMPs. Several cases of previously underestimated hadronic uncertainties are isolated. The results connect arbitrary models specified at the electroweak scale to a basis of $n_f=3$ flavor QCD operators. The complete basis of operators and Lorentz invariance constraints through order $v^2/c^2$ in the nonrelativistic nucleon effective theory are derived.
[ { "created": "Mon, 29 Sep 2014 20:00:16 GMT", "version": "v1" } ]
2015-03-05
[ [ "Hill", "Richard J.", "" ], [ "Solon", "Mikhail P.", "" ] ]
Models of Weakly Interacting Massive Particles (WIMPs) specified at the electroweak scale are systematically matched to effective theories at hadronic scales where WIMP-nucleus scattering observables are evaluated. Anomalous dimensions and heavy quark threshold matching conditions are computed for the complete basis of lowest-dimension effective operators involving quarks and gluons. The resulting QCD renormalization group evolution equations are solved. The status of relevant hadronic matrix elements is reviewed and phenomenological illustrations are given, including details for the computation of the universal limit of nucleon scattering with heavy $SU(2)_W\times U(1)_Y$ charged WIMPs. Several cases of previously underestimated hadronic uncertainties are isolated. The results connect arbitrary models specified at the electroweak scale to a basis of $n_f=3$ flavor QCD operators. The complete basis of operators and Lorentz invariance constraints through order $v^2/c^2$ in the nonrelativistic nucleon effective theory are derived.
2204.06605
Leandro Souza Nowacki
J V O Caetano, L S Nowacki, V S Fran\c{c}\~ao, R Hirayama, K P Pala, J O Sola, and F Grassi
Classical and relavistic simple wave problems solved with Smoothed Particle Hydrodynamics
5 pages, 2 figures, submitted to XLIV Brazilian Workshop Nuclear Physics 2021
null
10.1088/1742-6596/2340/1/012024
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To simulate the expansion of the matter created in relativistic nuclear collisions, codes in 3+1 dimensions are used and we are developing a new one. To benchmark such codes, the Sod's shock tube is often used. A closely related problem is the one-dimensional expansion of a gas into vacuum. In this paper, we study this problem classically and relativistically with the Smoothed Particle Method and test various techniques to improve the precision and speed of the solution.
[ { "created": "Wed, 13 Apr 2022 18:56:20 GMT", "version": "v1" } ]
2022-10-19
[ [ "Caetano", "J V O", "" ], [ "Nowacki", "L S", "" ], [ "Franção", "V S", "" ], [ "Hirayama", "R", "" ], [ "Pala", "K P", "" ], [ "Sola", "J O", "" ], [ "Grassi", "F", "" ] ]
To simulate the expansion of the matter created in relativistic nuclear collisions, codes in 3+1 dimensions are used and we are developing a new one. To benchmark such codes, the Sod's shock tube is often used. A closely related problem is the one-dimensional expansion of a gas into vacuum. In this paper, we study this problem classically and relativistically with the Smoothed Particle Method and test various techniques to improve the precision and speed of the solution.
0802.2882
Robert Fleischer
Robert Fleischer (CERN)
Flavour Physics and CP Violation: Expecting the LHC
58 pages, 35 figures, lectures given at the 4th CERN-CLAF School of High-Energy Physics, Vina del Mar (Valparaiso Region), Chile, 18 February - 3 March 2007, to appear in the Proceedings (CERN Report)
null
null
CERN-PH-TH/2008-034
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The starting point of these lectures is an introduction to the weak interactions of quarks and the Standard-Model description of CP violation, where the central role is played by the Cabibbo-Kobayashi-Maskawa matrix and the corresponding unitarity triangles. Since the B-meson system governs the stage of (quark) flavour physics and CP violation, it is our main focus: we shall classify B-meson decays, introduce the theoretical tools to deal with them, investigate the requirements for non-vanishing CP-violating asymmetries, and discuss the main strategies to explore CP violation and the preferred avenues for physics beyond the Standard Model to enter. This formalism allows us then to discuss important benchmark modes, where we will also address the question of how much space for new-physics effects in the B studies at the LHC is left by the recent experimental results from the B factories and the Tevatron.
[ { "created": "Wed, 20 Feb 2008 15:27:22 GMT", "version": "v1" } ]
2008-02-21
[ [ "Fleischer", "Robert", "", "CERN" ] ]
The starting point of these lectures is an introduction to the weak interactions of quarks and the Standard-Model description of CP violation, where the central role is played by the Cabibbo-Kobayashi-Maskawa matrix and the corresponding unitarity triangles. Since the B-meson system governs the stage of (quark) flavour physics and CP violation, it is our main focus: we shall classify B-meson decays, introduce the theoretical tools to deal with them, investigate the requirements for non-vanishing CP-violating asymmetries, and discuss the main strategies to explore CP violation and the preferred avenues for physics beyond the Standard Model to enter. This formalism allows us then to discuss important benchmark modes, where we will also address the question of how much space for new-physics effects in the B studies at the LHC is left by the recent experimental results from the B factories and the Tevatron.
hep-ph/9605360
null
Rudolph C. Hwa
Beyond Intermittency: Erraticity
10 pages + 4 figures (figures available upon request sent to hwa@oregon.uoregon.edu), Latex
Acta Phys.Polon. 27 (1996) 1789-1800
null
OITS-601
hep-ph nucl-th
null
Erraticity analysis of multiparticle production data is introduced as a way of extracting the maximum amount of information on self-similar fluctuations. It is presented as the next logical step to take beyond the intermittency analysis. An erraticity spectrum $e(\alpha)$ can be determined analogous to the multifractal spectrum $f(\alpha)$. An analytical example is presented to elucidate the method of analysis and the type of results that can be obtained.
[ { "created": "Mon, 20 May 1996 22:24:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hwa", "Rudolph C.", "" ] ]
Erraticity analysis of multiparticle production data is introduced as a way of extracting the maximum amount of information on self-similar fluctuations. It is presented as the next logical step to take beyond the intermittency analysis. An erraticity spectrum $e(\alpha)$ can be determined analogous to the multifractal spectrum $f(\alpha)$. An analytical example is presented to elucidate the method of analysis and the type of results that can be obtained.
hep-ph/9509324
null
A.D. Jackson and J.J.M. Verbaarschot (SUNY Stony Brook, NY)
A random matrix model for chiral symmetry breaking
Latex file with 6 figures with corrected .uu file appended
Phys.Rev. D53 (1996) 7223-7230
10.1103/PhysRevD.53.7223
SUNY-NTG-95/26
hep-ph
null
We formulate a random matrix model which mimics the chiral phase transition in QCD with two light flavors. Two critical exponents are calculated. We obtain the mean field values $\beta = \frac 12 $ and $\delta = 3$. We also find that the chiral phase transition can be characterized by the dynamics of the smallest eigenvalue of the Dirac operator. This suggests an alternative order parameter which may be of relevance for lattice QCD simulations.
[ { "created": "Mon, 18 Sep 1995 20:45:10 GMT", "version": "v1" }, { "created": "Tue, 19 Sep 1995 17:18:19 GMT", "version": "v2" }, { "created": "Wed, 20 Sep 1995 14:55:01 GMT", "version": "v3" } ]
2009-10-28
[ [ "Jackson", "A. D.", "", "SUNY Stony Brook, NY" ], [ "Verbaarschot", "J. J. M.", "", "SUNY Stony Brook, NY" ] ]
We formulate a random matrix model which mimics the chiral phase transition in QCD with two light flavors. Two critical exponents are calculated. We obtain the mean field values $\beta = \frac 12 $ and $\delta = 3$. We also find that the chiral phase transition can be characterized by the dynamics of the smallest eigenvalue of the Dirac operator. This suggests an alternative order parameter which may be of relevance for lattice QCD simulations.
hep-ph/9609499
Sei Umisedo Rcnp
S. Umisedo, S. Sasaki, H. Suganuma and H. Toki (RCNP)
Monopole Dominance for Dynamical Chiral-Symmetry Breaking in the Dual Ginzburg-Landau Theory
12pages, Latex (4 figures included in the revised version)
null
null
null
hep-ph
null
Using the effective potential formalism, we study dynamical chiral symmetry breaking (D$\chi$SB) in the dual Ginzburg-Landau (DGL) theory, where the color confinement is brought by monopole condensation. The effective potential as a function of infrared quark mass is found to have double-well structure, which leads to spontaneous breaking of chiral symmetry. To examine the role of confinement, we divide the effective potential into the confinement part and others, which correspond to the confinement term and other (Yukawa, Coulomb) terms of the gluon propagator in the DGL theory. It is found that the confinement part gives the dominating contribution to the \dcsb, which is regarded as monopole dominance for D$\chi$SB.
[ { "created": "Fri, 27 Sep 1996 05:12:56 GMT", "version": "v1" }, { "created": "Wed, 2 Oct 1996 06:12:27 GMT", "version": "v2" } ]
2009-09-25
[ [ "Umisedo", "S.", "", "RCNP" ], [ "Sasaki", "S.", "", "RCNP" ], [ "Suganuma", "H.", "", "RCNP" ], [ "Toki", "H.", "", "RCNP" ] ]
Using the effective potential formalism, we study dynamical chiral symmetry breaking (D$\chi$SB) in the dual Ginzburg-Landau (DGL) theory, where the color confinement is brought by monopole condensation. The effective potential as a function of infrared quark mass is found to have double-well structure, which leads to spontaneous breaking of chiral symmetry. To examine the role of confinement, we divide the effective potential into the confinement part and others, which correspond to the confinement term and other (Yukawa, Coulomb) terms of the gluon propagator in the DGL theory. It is found that the confinement part gives the dominating contribution to the \dcsb, which is regarded as monopole dominance for D$\chi$SB.
hep-ph/0105199
Alessia Tricomi
Alessia Tricomi
Discovery potential of charged Higgs at LHC in H+- ->tau nu decays
Talk given to the XXXVI Rencontres de Moriond, QCD and High Energy Hadronic Interactions, 17-24 March 2001, Les Arcs, Savoie, France
null
null
null
hep-ph
null
The discovery potential of charged Higgs from pp->tH+- in the H+- -> tau nu decay channel is investigated in CMS and ATLAS. For m_H>m_t, the most relevant channels are H+- -> tb and H+- -> tau nu. Whereas the former has the largest branching ratio it suffers of large irreducible backgrounds, while the latter offers a very clean enviroment when appropriate cuts are used. Making use of the tau polarization effects, in the purely hadronic final states an almost background-free signal is selected. The expected discovery range is evaluated for CMS and ATLAS with 30 fb^-1 each in the low luminosity running conditions and the combined results are presented.
[ { "created": "Sat, 19 May 2001 10:51:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tricomi", "Alessia", "" ] ]
The discovery potential of charged Higgs from pp->tH+- in the H+- -> tau nu decay channel is investigated in CMS and ATLAS. For m_H>m_t, the most relevant channels are H+- -> tb and H+- -> tau nu. Whereas the former has the largest branching ratio it suffers of large irreducible backgrounds, while the latter offers a very clean enviroment when appropriate cuts are used. Making use of the tau polarization effects, in the purely hadronic final states an almost background-free signal is selected. The expected discovery range is evaluated for CMS and ATLAS with 30 fb^-1 each in the low luminosity running conditions and the combined results are presented.
2205.02363
Jen-Chieh Peng
Jen-Chieh Peng and Gordon Baym
Inverse Tritium Beta Decay with Relic Neutrinos, Solar Neutrinos, and a 51Cr Source
5 pages, 4 figures, final version to appear in PRD
null
10.1103/PhysRevD.106.063018
null
hep-ph astro-ph.HE hep-ex nucl-ex
http://creativecommons.org/licenses/by/4.0/
The inverse tritium beta decay (ITBD) reaction, $\nu_e + ^3$H $\to e^- + ^3$He, is a promising experimental tool for observing relic neutrinos created in the early Universe. This reaction has been selected by the PTOLEMY experiment for the search of relic neutrinos. Despite its potential, the ITBD reaction induced by any sources of neutrinos has yet to be observed. We show that an intense $^{51}$Cr radioactive neutrino source is suitable for observing the ITBD reaction for the first time. As the Sun is another source of intense electron neutrinos, we also examine the ITBD reaction rate from solar neutrinos. Based on our recent studies on the evolution of the helicity of relic neutrinos, we further present the ITBD rate for capturing relic neutrinos as a function of neutrino mass hierarchy, the Dirac versus Majorana nature of neutrino, and the mass of the lightest neutrino.
[ { "created": "Wed, 4 May 2022 23:45:00 GMT", "version": "v1" }, { "created": "Wed, 14 Sep 2022 15:58:32 GMT", "version": "v2" } ]
2022-10-05
[ [ "Peng", "Jen-Chieh", "" ], [ "Baym", "Gordon", "" ] ]
The inverse tritium beta decay (ITBD) reaction, $\nu_e + ^3$H $\to e^- + ^3$He, is a promising experimental tool for observing relic neutrinos created in the early Universe. This reaction has been selected by the PTOLEMY experiment for the search of relic neutrinos. Despite its potential, the ITBD reaction induced by any sources of neutrinos has yet to be observed. We show that an intense $^{51}$Cr radioactive neutrino source is suitable for observing the ITBD reaction for the first time. As the Sun is another source of intense electron neutrinos, we also examine the ITBD reaction rate from solar neutrinos. Based on our recent studies on the evolution of the helicity of relic neutrinos, we further present the ITBD rate for capturing relic neutrinos as a function of neutrino mass hierarchy, the Dirac versus Majorana nature of neutrino, and the mass of the lightest neutrino.
2002.07201
Lauren Pearce
Peter Adshead, Lauren Pearce, Jessie Shelton, Zachary J. Weiner
Stochastic evolution of scalar fields with continuous symmetries during inflation
17 pages, 10 figures Updated to match version accepted by PRD
Phys. Rev. D 102, 023526 (2020)
10.1103/PhysRevD.102.023526
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
During inflation, scalar fields with masses less than the Hubble scale acquire vacuum expectation values (vevs) via stochastic processes driven by quantum fluctuations. For nearly massless spectator scalars transforming nontrivially under a continuous symmetry group, we demonstrate that the evolution of the vev depends on the dimensionality of the scalar field space. Fields in larger representations both attain larger vacuum expectation values and converge more rapidly to equilibrium. We present an argument demonstrating how this higher-dimensional evolution can be obtained in unitary gauge for fields transforming under local symmetries with a mass gap that is small compared to the Hubble scale. Finally, we show that accounting for the full number of degrees of freedom in the Standard Model Higgs multiplet tightens Higgs stability constraints on the inflationary scale at the percent level and has more dramatic consequences for both the vev and the energy stored in the Higgs field after inflation.
[ { "created": "Mon, 17 Feb 2020 19:02:06 GMT", "version": "v1" }, { "created": "Tue, 30 Jun 2020 19:59:43 GMT", "version": "v2" } ]
2020-07-22
[ [ "Adshead", "Peter", "" ], [ "Pearce", "Lauren", "" ], [ "Shelton", "Jessie", "" ], [ "Weiner", "Zachary J.", "" ] ]
During inflation, scalar fields with masses less than the Hubble scale acquire vacuum expectation values (vevs) via stochastic processes driven by quantum fluctuations. For nearly massless spectator scalars transforming nontrivially under a continuous symmetry group, we demonstrate that the evolution of the vev depends on the dimensionality of the scalar field space. Fields in larger representations both attain larger vacuum expectation values and converge more rapidly to equilibrium. We present an argument demonstrating how this higher-dimensional evolution can be obtained in unitary gauge for fields transforming under local symmetries with a mass gap that is small compared to the Hubble scale. Finally, we show that accounting for the full number of degrees of freedom in the Standard Model Higgs multiplet tightens Higgs stability constraints on the inflationary scale at the percent level and has more dramatic consequences for both the vev and the energy stored in the Higgs field after inflation.
1407.1001
Luis Oliver
A. Le Yaouanc, L. Oliver and J.-C. Raynal
Isgur-Wise functions and unitary representations of the Lorentz group : the meson case j = 1/2
arXiv admin note: substantial text overlap with arXiv:1402.0798, arXiv:0904.1942
Phys. Rev. D 90, 114016 (2014)
10.1103/PhysRevD.90.114016
LPT-Orsay-14-39
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We pursue the group theoretical method to study Isgur-Wise functions. We apply the general formalism, formerly applied to the baryon case j^P = 0^+ (for \Lambda_b -> \Lambda_c \ell \nu), to mesons with j^P = 1/2^-, i.e. $\overline{B} -> D(D^{(*)})\ell\nu. In this case, more involved from the angular momentum point of view, only the principal series of unitary representations of the Lorentz group contribute. We obtain an integral representation for the IW function xi(w) with a positive measure, recover the bounds for the slope and the curvature of xi(w) obtained from the Bjorken-Uraltsev sum rule method, and get new bounds for higher derivatives. We demonstrate also that if the lower bound for the slope is saturated, the measure is a delta-function, and xi(w) is given by an explicit elementary function. Inverting the integral formula, we obtain the measure in terms of the IW function, allowing to formulate criteria to decide if a given ansatz for the Isgur-Wise function is compatible or not with the sum rule constraints. Moreover, we have obtained an upper bound on the IW function valid for any value of w. We compare these theoretical constraints to a number of forms for \xi(w) proposed in the literature. The "dipole" function \xi(w) = (2/(w+1))^(2c) satisfies all constraints for c \geq 3/4, while the QCD Sum Rule result including condensates does not satisfy them. Special care is devoted to the Bakamjian-Thomas relativistic quark model in the heavy quark limit and to the description of the Lorentz group representation that underlies this model. Consistently, the IW function satisfies all Lorentz group criteria for any explicit form of the meson Hamiltonian at rest.
[ { "created": "Thu, 3 Jul 2014 18:09:31 GMT", "version": "v1" }, { "created": "Fri, 17 Oct 2014 11:25:33 GMT", "version": "v2" } ]
2014-12-17
[ [ "Yaouanc", "A. Le", "" ], [ "Oliver", "L.", "" ], [ "Raynal", "J. -C.", "" ] ]
We pursue the group theoretical method to study Isgur-Wise functions. We apply the general formalism, formerly applied to the baryon case j^P = 0^+ (for \Lambda_b -> \Lambda_c \ell \nu), to mesons with j^P = 1/2^-, i.e. $\overline{B} -> D(D^{(*)})\ell\nu. In this case, more involved from the angular momentum point of view, only the principal series of unitary representations of the Lorentz group contribute. We obtain an integral representation for the IW function xi(w) with a positive measure, recover the bounds for the slope and the curvature of xi(w) obtained from the Bjorken-Uraltsev sum rule method, and get new bounds for higher derivatives. We demonstrate also that if the lower bound for the slope is saturated, the measure is a delta-function, and xi(w) is given by an explicit elementary function. Inverting the integral formula, we obtain the measure in terms of the IW function, allowing to formulate criteria to decide if a given ansatz for the Isgur-Wise function is compatible or not with the sum rule constraints. Moreover, we have obtained an upper bound on the IW function valid for any value of w. We compare these theoretical constraints to a number of forms for \xi(w) proposed in the literature. The "dipole" function \xi(w) = (2/(w+1))^(2c) satisfies all constraints for c \geq 3/4, while the QCD Sum Rule result including condensates does not satisfy them. Special care is devoted to the Bakamjian-Thomas relativistic quark model in the heavy quark limit and to the description of the Lorentz group representation that underlies this model. Consistently, the IW function satisfies all Lorentz group criteria for any explicit form of the meson Hamiltonian at rest.
hep-ph/0306089
S. Bhattacharyya
Bhaskar De and S. Bhattacharyya
The $p_T$-Spectra of Some Non-pion Secondaries in High Energy NN to NA/AA Collisions and the Combinational Approach
25 pages, 18 figures; accepted for publication in IJMPA
Int.J.Mod.Phys. A19 (2004) 3225-3244
10.1142/S0217751X04017896
null
hep-ph nucl-th
null
In continuation of our perusal of the studies on transverse momentum spectra for the main varieties of secondaries from a consistent and comprehensive phenomenological approach, we propose to take up here -- after a successful completion of reporting in detail the results (Ref.[4] in the text) on our analyses of the $p_T$-spectra of pions -- the studies specially on production of kaons, protons and antiprotons in several proton-induced and nucleus-involved collisions at high energies. The measured data on inclusive cross sections of kaons, protons and antiprotons from the various published sources have here been assorted first. Next, data on the $p_T$-spectra of the specific secondaries produced in PP and $P\bar{P}$ reactions have been scanned and analyzed with the help of Hagedorn's model(HM). Thereafter a connector, named here the combinational approach(CA), has been constructed and used to analyze the data on $p_T$-spectra of some major category of non-pion secondaries produced in nucleus-nucleus(AA/AB) collisions at high energies. And these exercises have, finally, led to the modestly successful interpretations of a wide band of data with the revelation of some insightful physical aspects of high energy interactions. The limitations of the approach have also been precisely pointed out in the end.
[ { "created": "Wed, 11 Jun 2003 08:48:25 GMT", "version": "v1" } ]
2009-11-10
[ [ "De", "Bhaskar", "" ], [ "Bhattacharyya", "S.", "" ] ]
In continuation of our perusal of the studies on transverse momentum spectra for the main varieties of secondaries from a consistent and comprehensive phenomenological approach, we propose to take up here -- after a successful completion of reporting in detail the results (Ref.[4] in the text) on our analyses of the $p_T$-spectra of pions -- the studies specially on production of kaons, protons and antiprotons in several proton-induced and nucleus-involved collisions at high energies. The measured data on inclusive cross sections of kaons, protons and antiprotons from the various published sources have here been assorted first. Next, data on the $p_T$-spectra of the specific secondaries produced in PP and $P\bar{P}$ reactions have been scanned and analyzed with the help of Hagedorn's model(HM). Thereafter a connector, named here the combinational approach(CA), has been constructed and used to analyze the data on $p_T$-spectra of some major category of non-pion secondaries produced in nucleus-nucleus(AA/AB) collisions at high energies. And these exercises have, finally, led to the modestly successful interpretations of a wide band of data with the revelation of some insightful physical aspects of high energy interactions. The limitations of the approach have also been precisely pointed out in the end.
1409.0868
Rodrigo Alonso Dr
Rodrigo Alonso, Elizabeth E. Jenkins, and Aneesh V. Manohar
Holomorphy without Supersymmetry in the Standard Model Effective Field Theory
Minor corrections in Table I, see note added at end of paper. The complete SMEFT RGE will be maintained at http://einstein.ucsd.edu/smeft
null
10.1016/j.physletb.2014.10.045
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The anomalous dimensions of dimension-six operators in the Standard Model Effective Field Theory (SMEFT) respect holomorphy to a large extent. The holomorphy conditions are reminiscent of supersymmetry, even though the SMEFT is not a supersymmetric theory.
[ { "created": "Tue, 2 Sep 2014 20:00:44 GMT", "version": "v1" }, { "created": "Thu, 6 Nov 2014 01:08:17 GMT", "version": "v2" }, { "created": "Thu, 30 Jul 2015 19:32:44 GMT", "version": "v3" } ]
2015-07-31
[ [ "Alonso", "Rodrigo", "" ], [ "Jenkins", "Elizabeth E.", "" ], [ "Manohar", "Aneesh V.", "" ] ]
The anomalous dimensions of dimension-six operators in the Standard Model Effective Field Theory (SMEFT) respect holomorphy to a large extent. The holomorphy conditions are reminiscent of supersymmetry, even though the SMEFT is not a supersymmetric theory.
hep-ph/9609429
Fyodor V. Tkachov
Fyodor V. Tkachov (INR Russ. Acad. Sci., Moscow)
Algebraic algorithms for multiloop calculations. The first 15 years. What's next?
5 pages, PS; 7-11-98: maintenance (PS, misprints, etc.)
Nucl.Instrum.Meth.A389:309-313,1997
10.1016/S0168-9002(97)00110-1
null
hep-ph hep-th
null
The ideas behind the concept of algebraic ("integration-by-parts") algorithms for multiloop calculations are reviewed. For any topology and mass pattern, a finite iterative algebraic procedure is proved to exist which transforms the corresponding Feynman-parametrized integrands into a form that is optimal for numerical integration, with all the poles in D-4 explicitly extracted.
[ { "created": "Sat, 21 Sep 1996 18:15:11 GMT", "version": "v1" }, { "created": "Sat, 7 Nov 1998 04:34:42 GMT", "version": "v2" } ]
2011-04-15
[ [ "Tkachov", "Fyodor V.", "", "INR Russ. Acad. Sci., Moscow" ] ]
The ideas behind the concept of algebraic ("integration-by-parts") algorithms for multiloop calculations are reviewed. For any topology and mass pattern, a finite iterative algebraic procedure is proved to exist which transforms the corresponding Feynman-parametrized integrands into a form that is optimal for numerical integration, with all the poles in D-4 explicitly extracted.
hep-ph/0201285
Peschanski
H. Navelet and R. Peschanski
Conformal invariant saturation
15 pages,3 eps figures; Version to be published in Nucl.Phys.B., one more figure, writing improvements, results and conclusion unchanged
Nucl.Phys.B634:291-308,2002
10.1016/S0550-3213(02)00314-0
SPhT (Saclay): t02/019
hep-ph
null
We show that, in onium-onium scattering at (very) high energy, a transition to saturation happens due to quantum fluctuations of QCD dipoles. This transition starts when the order $\alpha^2$ correction of the dipole loop is compensated by its faster energy evolution, leading to a negative interference with the tree level amplitude. After a derivation of the the one-loop dipole contribution using conformal invariance of the elastic 4-gluon amplitude in high energy QCD, we obtain an exact expression of the saturation line in the plane (Y,L) where Y is the total rapidity and L, the logarithm of the onium scale ratio. It shows universal features implying the Balitskyi - Fadin - Kuraev - Lipatov (BFKL) evolution kernel and the square of the QCD triple Pomeron vertex. For large L, only the higher BFKL Eigenvalue contributes, leading to a saturation depending on leading log perturbative QCD characteristics. For initial onium scales of same order, however, it involves an unlimited summation over all conformal BFKL Eigenstates. In all cases, conformal invariance is preserved for the saturation mechanism based on dipole loops.
[ { "created": "Wed, 30 Jan 2002 14:29:56 GMT", "version": "v1" }, { "created": "Tue, 23 Apr 2002 09:14:31 GMT", "version": "v2" } ]
2008-11-26
[ [ "Navelet", "H.", "" ], [ "Peschanski", "R.", "" ] ]
We show that, in onium-onium scattering at (very) high energy, a transition to saturation happens due to quantum fluctuations of QCD dipoles. This transition starts when the order $\alpha^2$ correction of the dipole loop is compensated by its faster energy evolution, leading to a negative interference with the tree level amplitude. After a derivation of the the one-loop dipole contribution using conformal invariance of the elastic 4-gluon amplitude in high energy QCD, we obtain an exact expression of the saturation line in the plane (Y,L) where Y is the total rapidity and L, the logarithm of the onium scale ratio. It shows universal features implying the Balitskyi - Fadin - Kuraev - Lipatov (BFKL) evolution kernel and the square of the QCD triple Pomeron vertex. For large L, only the higher BFKL Eigenvalue contributes, leading to a saturation depending on leading log perturbative QCD characteristics. For initial onium scales of same order, however, it involves an unlimited summation over all conformal BFKL Eigenstates. In all cases, conformal invariance is preserved for the saturation mechanism based on dipole loops.
1305.4350
Amir Nawaz Khan
Amir N. Khan, Douglas W. McKay, F. Tahir
Sensitivity of medium-baseline reactor neutrino mass-hierarchy experiments to nonstandard interactions
15 pages, 9 figures, 2 tables, references added, published in PRD
Phys. Rev. D 88, 113006 (2013)
10.1103/PhysRevD.88.113006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the impact of nonstandard interactions at source and detector on the interpretation of reactor electron neutrino disappearance experiments with short- and medium-baseline designs. We use the constraints from the recent results from short-baseline experiments and generalize current estimates of medium-baseline event rates to include charged current interactions at source and detector with standard Lorentz structure but with nonstandard flavor structure. We find that the average spectrum of observed events at a baseline of 50 km, in the middle of the currently favored region, provides a probe of new interactions. We show that an improvement in sensitivity to nonstandard interactions is possible if combined with improved precision of input mixing parameters in independent experiments, despite ambiguity in interpretation of medium-baseline data. We show that nonstandard interactions can enhance or suppress the sensitivity of experiments to the mass hierarchy, depending on the phases of the parameters and the CP-violating phase in the standard three-neutrino mixing picture.
[ { "created": "Sun, 19 May 2013 11:35:12 GMT", "version": "v1" }, { "created": "Sun, 22 Sep 2013 05:16:44 GMT", "version": "v2" }, { "created": "Wed, 11 Dec 2013 17:38:45 GMT", "version": "v3" } ]
2013-12-16
[ [ "Khan", "Amir N.", "" ], [ "McKay", "Douglas W.", "" ], [ "Tahir", "F.", "" ] ]
We explore the impact of nonstandard interactions at source and detector on the interpretation of reactor electron neutrino disappearance experiments with short- and medium-baseline designs. We use the constraints from the recent results from short-baseline experiments and generalize current estimates of medium-baseline event rates to include charged current interactions at source and detector with standard Lorentz structure but with nonstandard flavor structure. We find that the average spectrum of observed events at a baseline of 50 km, in the middle of the currently favored region, provides a probe of new interactions. We show that an improvement in sensitivity to nonstandard interactions is possible if combined with improved precision of input mixing parameters in independent experiments, despite ambiguity in interpretation of medium-baseline data. We show that nonstandard interactions can enhance or suppress the sensitivity of experiments to the mass hierarchy, depending on the phases of the parameters and the CP-violating phase in the standard three-neutrino mixing picture.
hep-ph/9411345
Georg Botz
Otto Nachtmann
Nonperturbative QCD Effects in High Energy Collisions
Talk presented at the 18th Johns Hopkins Workshop, Florence, 1994 LaTeX, no special macros required, 18 pages; figs appended as uuencoded ps
null
null
HD-THEP-94-42
hep-ph nucl-th
null
High energy hadron-hadron collisions are discussed. It is argued that soft collisions should involve in an essential way nonperturbative QCD. A way is outlined how to calculate properties of high energy elastic hadron-hadron scattering using field theoretic methods. The functional integrals occuring there are evaluated using the ``stochastic vacuum model''. A satisfactory comparison between theory and experiment is achieved. Then the question of possible nonperturbative QCD effects in high energy hard hadron-hadron collisions is raised. It is shown that some spin effects in the Drell-Yan process may give a hint that such effects exist indeed in nature.
[ { "created": "Mon, 21 Nov 1994 07:50:37 GMT", "version": "v1" } ]
2009-09-25
[ [ "Nachtmann", "Otto", "" ] ]
High energy hadron-hadron collisions are discussed. It is argued that soft collisions should involve in an essential way nonperturbative QCD. A way is outlined how to calculate properties of high energy elastic hadron-hadron scattering using field theoretic methods. The functional integrals occuring there are evaluated using the ``stochastic vacuum model''. A satisfactory comparison between theory and experiment is achieved. Then the question of possible nonperturbative QCD effects in high energy hard hadron-hadron collisions is raised. It is shown that some spin effects in the Drell-Yan process may give a hint that such effects exist indeed in nature.
1601.04718
Pedro David Ruiz-Femenia
M. Beneke, A. Bharucha, F. Dighera, C. Hellmann, A. Hryczuk, S. Recksiegel, P. Ruiz-Femenia
Relic density of wino-like dark matter in the MSSM
49 pages, 15 figures
null
10.1007/JHEP03(2016)119
TUM-HEP-1033/15
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The relic density of TeV-scale wino-like neutralino dark matter in the MSSM is subject to potentially large corrections as a result of the Sommerfeld effect. A recently developed framework enables us to calculate the Sommerfeld-enhanced relic density in general MSSM scenarios, properly treating mixed states and multiple co-annihilating channels as well as including off-diagonal contributions. Using this framework, including on-shell one-loop mass splittings and running couplings and taking into account the latest experimental constraints, we perform a thorough study of the regions of parameter space surrounding the well known pure-wino scenario: namely the effect of sfermion masses being non-decoupled and of allowing non-negligible Higgsino or bino components in the lightest neutralino. We further perform an investigation into the effect of thermal corrections and show that these can safely be neglected. The results reveal a number of phenomenologically interesting but so far unexplored regions where the Sommerfeld effect is sizeable. We find, in particular, that the relic density can agree with experiment for dominantly wino neutralino dark matter with masses ranging from 1.7 to beyond 4 TeV. In light of these results the bounds from Indirect Detection on wino-like dark matter should be revisited.
[ { "created": "Mon, 18 Jan 2016 21:00:34 GMT", "version": "v1" } ]
2016-04-20
[ [ "Beneke", "M.", "" ], [ "Bharucha", "A.", "" ], [ "Dighera", "F.", "" ], [ "Hellmann", "C.", "" ], [ "Hryczuk", "A.", "" ], [ "Recksiegel", "S.", "" ], [ "Ruiz-Femenia", "P.", "" ] ]
The relic density of TeV-scale wino-like neutralino dark matter in the MSSM is subject to potentially large corrections as a result of the Sommerfeld effect. A recently developed framework enables us to calculate the Sommerfeld-enhanced relic density in general MSSM scenarios, properly treating mixed states and multiple co-annihilating channels as well as including off-diagonal contributions. Using this framework, including on-shell one-loop mass splittings and running couplings and taking into account the latest experimental constraints, we perform a thorough study of the regions of parameter space surrounding the well known pure-wino scenario: namely the effect of sfermion masses being non-decoupled and of allowing non-negligible Higgsino or bino components in the lightest neutralino. We further perform an investigation into the effect of thermal corrections and show that these can safely be neglected. The results reveal a number of phenomenologically interesting but so far unexplored regions where the Sommerfeld effect is sizeable. We find, in particular, that the relic density can agree with experiment for dominantly wino neutralino dark matter with masses ranging from 1.7 to beyond 4 TeV. In light of these results the bounds from Indirect Detection on wino-like dark matter should be revisited.
hep-ph/9904399
Hitoshi Murayama
Andre de Gouvea, Alexander Friedland, and Hitoshi Murayama (UC Berkeley, LBNL)
Seasonal Variations of the 7Be Solar Neutrino Flux
39 pages, 13 figures, uses psfig. Now the impact of the MSW effect on vacuum oscillations taken into account. Conclusions unchanged. References added
Phys.Rev.D60:093011,1999
10.1103/PhysRevD.60.093011
LBNL-43104, UCB-PTH-99/15
hep-ph astro-ph hep-ex nucl-ex
null
Measuring the 7Be solar neutrino flux is crucial towards solving the solar neutrino puzzle. The Borexino experiment, and possibly the KamLAND experiment, will be capable of studying the 7Be neutrinos in the near future. We discuss (1) how the seasonal variation of the Borexino and KamLAND data can be used to measure the 7Be solar neutrino flux in a background independent way and (2) how anomalous seasonal variations might be used to discover vacuum neutrino oscillations, independent of the solar model and the measurement of the background. In particular, we find that, after three years of Borexino or KamLAND running, vacuum neutrino oscillations can be either established or excluded for almost all values of (sin^2 2 theta, Delta m^2) preferred by the Homestake, GALLEX, SAGE, and Super-Kamiokande data. We also discuss how well seasonal variations of the data can be used to measure (sin^2 2 theta, Delta m^2) in the case of vacuum oscillations.
[ { "created": "Tue, 20 Apr 1999 17:10:46 GMT", "version": "v1" }, { "created": "Wed, 5 May 1999 01:15:02 GMT", "version": "v2" } ]
2009-09-29
[ [ "de Gouvea", "Andre", "", "UC\n Berkeley, LBNL" ], [ "Friedland", "Alexander", "", "UC\n Berkeley, LBNL" ], [ "Murayama", "Hitoshi", "", "UC\n Berkeley, LBNL" ] ]
Measuring the 7Be solar neutrino flux is crucial towards solving the solar neutrino puzzle. The Borexino experiment, and possibly the KamLAND experiment, will be capable of studying the 7Be neutrinos in the near future. We discuss (1) how the seasonal variation of the Borexino and KamLAND data can be used to measure the 7Be solar neutrino flux in a background independent way and (2) how anomalous seasonal variations might be used to discover vacuum neutrino oscillations, independent of the solar model and the measurement of the background. In particular, we find that, after three years of Borexino or KamLAND running, vacuum neutrino oscillations can be either established or excluded for almost all values of (sin^2 2 theta, Delta m^2) preferred by the Homestake, GALLEX, SAGE, and Super-Kamiokande data. We also discuss how well seasonal variations of the data can be used to measure (sin^2 2 theta, Delta m^2) in the case of vacuum oscillations.
1606.03239
Juan Nieves Dr.
E. Cincioglu, J. Nieves, A. Ozpineci and A. U. Yilmazer
Quarkonium Contribution to Meson Molecules
46 pages, 5 figures; Accepted in EPJC
null
10.1140/epjc/s10052-016-4413-1
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Starting from a molecular picture for the X(3872) resonance, this state and its J^{PC}=2++ HQSS partner [X2(4012)] are analyzed within a model which incorporates possible mixings with 2P charmonium states. Since it is reasonable to expect the bare chi_{c1}(2P) to be located above the D\bar D* threshold, but relatively close to it, the presence of the charmonium state provides an effective attraction that will contribute to bind the X(3872), but it will not appear in the 2++ sector. Indeed in this latter sector, the chi_{c2}(2P) should provide an effective small repulsion, because it is placed well below the D*\bar D* threshold. We show how the 1++ and 2++ bare charmonium poles are modified due to the D(*)\bar D(*) loop effects, and the first one is moved to the complex plane. The meson loops produce, besides some shifts in the masses of the charmonia, a finite width for the 1++ dressed charmonium state. On the other hand, the X(3872) and X2(4012) start developing some charmonium content, which is estimated by means of the compositeness Weinberg sum-rule. We also show that for X(3872) molecular probabilities of around 70-90 %, the X2 resonance destabilizes and disappears from the spectrum, becoming either a virtual state or being located deep into the complex plane, with decreasing influence in the D* \bar D* scattering line.
[ { "created": "Fri, 10 Jun 2016 09:15:48 GMT", "version": "v1" }, { "created": "Sun, 2 Oct 2016 09:07:32 GMT", "version": "v2" } ]
2016-11-23
[ [ "Cincioglu", "E.", "" ], [ "Nieves", "J.", "" ], [ "Ozpineci", "A.", "" ], [ "Yilmazer", "A. U.", "" ] ]
Starting from a molecular picture for the X(3872) resonance, this state and its J^{PC}=2++ HQSS partner [X2(4012)] are analyzed within a model which incorporates possible mixings with 2P charmonium states. Since it is reasonable to expect the bare chi_{c1}(2P) to be located above the D\bar D* threshold, but relatively close to it, the presence of the charmonium state provides an effective attraction that will contribute to bind the X(3872), but it will not appear in the 2++ sector. Indeed in this latter sector, the chi_{c2}(2P) should provide an effective small repulsion, because it is placed well below the D*\bar D* threshold. We show how the 1++ and 2++ bare charmonium poles are modified due to the D(*)\bar D(*) loop effects, and the first one is moved to the complex plane. The meson loops produce, besides some shifts in the masses of the charmonia, a finite width for the 1++ dressed charmonium state. On the other hand, the X(3872) and X2(4012) start developing some charmonium content, which is estimated by means of the compositeness Weinberg sum-rule. We also show that for X(3872) molecular probabilities of around 70-90 %, the X2 resonance destabilizes and disappears from the spectrum, becoming either a virtual state or being located deep into the complex plane, with decreasing influence in the D* \bar D* scattering line.
1002.2140
Sebastian J\"ager
Sebastian Jager
Theoretical overview of b->s hadronic decays
talk at Beauty09, Heidelberg, September 7-11, 2009
null
null
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
A wealth of data on hadronic b -> s transitions is available from the B-factories and will be improved at the LHCb experiment and possible future super-B-factories. I review the theory of these decays as it pertains to the search for physics beyond the Standard Model and various puzzles in the present data.
[ { "created": "Wed, 10 Feb 2010 17:21:18 GMT", "version": "v1" } ]
2010-02-11
[ [ "Jager", "Sebastian", "" ] ]
A wealth of data on hadronic b -> s transitions is available from the B-factories and will be improved at the LHCb experiment and possible future super-B-factories. I review the theory of these decays as it pertains to the search for physics beyond the Standard Model and various puzzles in the present data.
2312.00872
Anh Vu Phan
Anh Vu Phan, Susanne Westhoff
Precise tests of the axion coupling to tops
27 pages, 7 figures
JHEP 05 (2024) 075
10.1007/JHEP05(2024)075
null
hep-ph hep-ex
http://creativecommons.org/licenses/by-nc-nd/4.0/
We present an in-depth analysis of axions and axion-like particles in top-pair production at the LHC. Our main goal is to probe the axion coupling to top quarks at high energies. To this end, we calculate the top-antitop cross section and differential distributions including ALP effects up to one-loop level. By comparing these predictions with LHC precision measurements, we constrain the top coupling of axion-like particles with masses below the top-antitop threshold. Our results apply to all UV completions of the ALP effective theory with dominant couplings to top quarks, in particular to DFSZ-like axion models.
[ { "created": "Fri, 1 Dec 2023 19:01:45 GMT", "version": "v1" }, { "created": "Fri, 7 Jun 2024 07:52:04 GMT", "version": "v2" } ]
2024-06-10
[ [ "Phan", "Anh Vu", "" ], [ "Westhoff", "Susanne", "" ] ]
We present an in-depth analysis of axions and axion-like particles in top-pair production at the LHC. Our main goal is to probe the axion coupling to top quarks at high energies. To this end, we calculate the top-antitop cross section and differential distributions including ALP effects up to one-loop level. By comparing these predictions with LHC precision measurements, we constrain the top coupling of axion-like particles with masses below the top-antitop threshold. Our results apply to all UV completions of the ALP effective theory with dominant couplings to top quarks, in particular to DFSZ-like axion models.
1708.06918
Zhan-Wei Liu
Hao Xu, Bo Wang, Zhan-Wei Liu, Xiang Liu
$D D^{*}$ potentials in chiral perturbation theory and possible molecular states
18 pages, 12 figures. Published in Phys. Rev. D. We correct three typos in which $I=1$ and $I=0$ were mistaken for each other
Phys. Rev. D 99, 014027 (2019)
10.1103/PhysRevD.99.014027
null
hep-ph hep-ex hep-lat nucl-th
http://creativecommons.org/licenses/by/4.0/
The $DD^{*}$ potentials are studied within the framework of heavy meson chiral effective field theory. We obtain the effective potentials of the $DD^{*}$ system up to $O(\epsilon^2)$ at the one-loop level. In addition to the one-pion exchange contribution, the contact and two-pion exchange interactions are also investigated in detail. Furthermore, we search for the possible molecular states by solving the Schr\"odinger equation with the potentials. We notice that the contact and two-pion exchange potentials are numerically non-negligible and important for the existence of a bound state. In our results, no bound state is found in the $I=1$ channel within a wide range of cutoff parameter, while there exists a bound state in the $I=0$ channel as the cutoff is near $m_\rho$ in our approach.
[ { "created": "Wed, 23 Aug 2017 08:46:23 GMT", "version": "v1" }, { "created": "Sun, 6 Jan 2019 06:03:08 GMT", "version": "v2" }, { "created": "Sun, 5 Dec 2021 10:45:35 GMT", "version": "v3" } ]
2021-12-07
[ [ "Xu", "Hao", "" ], [ "Wang", "Bo", "" ], [ "Liu", "Zhan-Wei", "" ], [ "Liu", "Xiang", "" ] ]
The $DD^{*}$ potentials are studied within the framework of heavy meson chiral effective field theory. We obtain the effective potentials of the $DD^{*}$ system up to $O(\epsilon^2)$ at the one-loop level. In addition to the one-pion exchange contribution, the contact and two-pion exchange interactions are also investigated in detail. Furthermore, we search for the possible molecular states by solving the Schr\"odinger equation with the potentials. We notice that the contact and two-pion exchange potentials are numerically non-negligible and important for the existence of a bound state. In our results, no bound state is found in the $I=1$ channel within a wide range of cutoff parameter, while there exists a bound state in the $I=0$ channel as the cutoff is near $m_\rho$ in our approach.
hep-ph/0109100
Mikko Laine
K. Kajantie, M. Laine, Y. Schroder
A simple way to generate high order vacuum graphs
19 pages. Reference added. To appear in Phys.Rev.D
Phys.Rev. D65 (2002) 045008
10.1103/PhysRevD.65.045008
null
hep-ph hep-th
null
We describe an efficient practical procedure for enumerating and regrouping vacuum Feynman graphs of a given order in perturbation theory. The method is based on a combination of Schwinger-Dyson equations and the two-particle-irreducible ("skeleton") expansion. The regrouping leads to skeletons containing only free propagators, together with "ring diagrams" containing all the self-energy insertions. As a consequence, relatively few diagrams need to be drawn and integrations carried out at any single stage of the computation and, in low dimensions, overlapping ultraviolet/infrared subdivergences can be cleanly isolated. As an illustration we enumerate the graphs contributing to the 4-loop free energy in QCD, explicitly in a continuum and more compactly in a lattice regularization.
[ { "created": "Wed, 12 Sep 2001 16:25:36 GMT", "version": "v1" }, { "created": "Wed, 21 Nov 2001 16:56:34 GMT", "version": "v2" } ]
2009-11-07
[ [ "Kajantie", "K.", "" ], [ "Laine", "M.", "" ], [ "Schroder", "Y.", "" ] ]
We describe an efficient practical procedure for enumerating and regrouping vacuum Feynman graphs of a given order in perturbation theory. The method is based on a combination of Schwinger-Dyson equations and the two-particle-irreducible ("skeleton") expansion. The regrouping leads to skeletons containing only free propagators, together with "ring diagrams" containing all the self-energy insertions. As a consequence, relatively few diagrams need to be drawn and integrations carried out at any single stage of the computation and, in low dimensions, overlapping ultraviolet/infrared subdivergences can be cleanly isolated. As an illustration we enumerate the graphs contributing to the 4-loop free energy in QCD, explicitly in a continuum and more compactly in a lattice regularization.
2202.10514
Venus Keus
Jaime Hernandez-Sanchez, Venus Keus, Stefano Moretti, Dorota Sokolowska
Complementary collider and astrophysical probes of multi-component Dark Matter
20 pages, 7 figures, 2 tables. arXiv admin note: substantial text overlap with arXiv:2012.11621
null
10.1007/JHEP03(2023)045
DIAS-STP-22-01
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We study a new physics scenario with two inert and one active scalar doublets, hence a 3-Higgs Doublet Model (3HDM). We impose a $Z_2 \times Z'_2$ symmetry onto such a 3HDM with one inert doublet odd under the $Z_2$ transformation and the other odd under the $Z'_2$ one. Such a construction leads to a two-component Dark Matter (DM) model. It has been shown that, when there is a sufficient mass difference between the two DM candidates, it is possible to probe the light DM candidate in the nuclear recoil energy in direct detection experiments and the heavy DM component in the photon flux in indirect detection experiments. With the DM masses at the electroweak scale, we show that, independently of astrophysical probes, this model feature can be tested at the Large Hadron Collider via scalar cascade decays in $2 \ell + \cancel{E}_T$ final states. We study several observable distributions whose shapes hint at the presence of the two different DM candidates.
[ { "created": "Mon, 21 Feb 2022 20:06:28 GMT", "version": "v1" } ]
2023-03-29
[ [ "Hernandez-Sanchez", "Jaime", "" ], [ "Keus", "Venus", "" ], [ "Moretti", "Stefano", "" ], [ "Sokolowska", "Dorota", "" ] ]
We study a new physics scenario with two inert and one active scalar doublets, hence a 3-Higgs Doublet Model (3HDM). We impose a $Z_2 \times Z'_2$ symmetry onto such a 3HDM with one inert doublet odd under the $Z_2$ transformation and the other odd under the $Z'_2$ one. Such a construction leads to a two-component Dark Matter (DM) model. It has been shown that, when there is a sufficient mass difference between the two DM candidates, it is possible to probe the light DM candidate in the nuclear recoil energy in direct detection experiments and the heavy DM component in the photon flux in indirect detection experiments. With the DM masses at the electroweak scale, we show that, independently of astrophysical probes, this model feature can be tested at the Large Hadron Collider via scalar cascade decays in $2 \ell + \cancel{E}_T$ final states. We study several observable distributions whose shapes hint at the presence of the two different DM candidates.
hep-ph/0109105
S. M. Zebarjad
M. Haghighat, S.M. Zebarjad and F. Loran
Positronium Hyperfine Splitting in Non-commutative Space at the Order $\alpha^6$
7 pages, 2 figures, to appear in Phys. Rev. D
Phys.Rev. D66 (2002) 016005
10.1103/PhysRevD.66.016005
null
hep-ph
null
We obtain positronium Hyperfine Splitting owing to the non-commutativity of space and show that, in the leading order, it is proportional to $\theta \alpha^6$ where, $\theta$ is the parameter of non-commutativity. It is also shown that spatial non-commutativity splits the spacing between $n=2$ triplet excited levels $E(2^3S_1)\to E(2^3P_2)$ which provides an experimental test on the non-commutativity of space.
[ { "created": "Wed, 12 Sep 2001 12:45:55 GMT", "version": "v1" }, { "created": "Sat, 8 Jun 2002 11:17:10 GMT", "version": "v2" } ]
2009-11-07
[ [ "Haghighat", "M.", "" ], [ "Zebarjad", "S. M.", "" ], [ "Loran", "F.", "" ] ]
We obtain positronium Hyperfine Splitting owing to the non-commutativity of space and show that, in the leading order, it is proportional to $\theta \alpha^6$ where, $\theta$ is the parameter of non-commutativity. It is also shown that spatial non-commutativity splits the spacing between $n=2$ triplet excited levels $E(2^3S_1)\to E(2^3P_2)$ which provides an experimental test on the non-commutativity of space.
2408.01143
Hiroshi Okada
Takaaki Nomura, Hiroshi Okada
Type-II seesaw of a non-holomorphic modular $A_4$ symmetry
11 pages, 6 figures, 1 table. arXiv admin note: text overlap with arXiv:2407.13167
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We search for predictability of lepton masses and mixing patterns of type-II seesaw scenario in a non-holomorphic modular $A_4$ symmetry recently proposed by "Qu" and "Ding". We propose three types of minimum predictive models with different assignments of modular weight, satisfying the neutrino oscillation data in Nufit 5.2. The cosmological bound on the sum of neutrino mass is stringent to our models and CMB bound $\sum D_\nu\le0.12$ eV can be satisfied by one of three models playing an important role in discriminating them.
[ { "created": "Fri, 2 Aug 2024 09:41:49 GMT", "version": "v1" } ]
2024-08-05
[ [ "Nomura", "Takaaki", "" ], [ "Okada", "Hiroshi", "" ] ]
We search for predictability of lepton masses and mixing patterns of type-II seesaw scenario in a non-holomorphic modular $A_4$ symmetry recently proposed by "Qu" and "Ding". We propose three types of minimum predictive models with different assignments of modular weight, satisfying the neutrino oscillation data in Nufit 5.2. The cosmological bound on the sum of neutrino mass is stringent to our models and CMB bound $\sum D_\nu\le0.12$ eV can be satisfied by one of three models playing an important role in discriminating them.
hep-ph/0508201
Simon Turbide
Simon Turbide (McGill U.), Charles Gale (McGill U.) and Rainer J. Fries (U. Minnesota)
Azimuthal Asymmetry of Direct Photons in High Energy Nuclear Collisions
New title. Final version
Phys.Rev.Lett. 96 (2006) 032303
10.1103/PhysRevLett.96.032303
null
hep-ph nucl-th
null
We show that a sizeable azimuthal asymmetry, characterized by a coefficient v_2, is to be expected for direct photons produced in non-central high energy nuclear collisions. This signal is generated by photons radiated by jets interacting with the surrounding hot plasma. The anisotropy is out of phase by an angle $\pi/2$ with respect to that associated with the elliptic anisotropy of hadrons, leading to negative values of v_2. Such an asymmetry, if observed, could be a signature for the presence of a quark gluon plasma and would establish the importance of jet-plasma interactions as a source of electromagnetic radiation.
[ { "created": "Thu, 18 Aug 2005 19:15:28 GMT", "version": "v1" }, { "created": "Wed, 16 Nov 2005 20:13:01 GMT", "version": "v2" }, { "created": "Tue, 10 Jan 2006 19:41:51 GMT", "version": "v3" } ]
2009-11-11
[ [ "Turbide", "Simon", "", "McGill U." ], [ "Gale", "Charles", "", "McGill U." ], [ "Fries", "Rainer J.", "", "U. Minnesota" ] ]
We show that a sizeable azimuthal asymmetry, characterized by a coefficient v_2, is to be expected for direct photons produced in non-central high energy nuclear collisions. This signal is generated by photons radiated by jets interacting with the surrounding hot plasma. The anisotropy is out of phase by an angle $\pi/2$ with respect to that associated with the elliptic anisotropy of hadrons, leading to negative values of v_2. Such an asymmetry, if observed, could be a signature for the presence of a quark gluon plasma and would establish the importance of jet-plasma interactions as a source of electromagnetic radiation.
2103.02222
Javier Vijande Asenjo
Jean-Marc Richard, Alfredo Valcarce, Javier Vijande
Effect of relativistic kinematics on the stability of multiquarks
7 pages, 8 figures. To be published in Phys. Rev. D
Phys. Rev. D 103, 054020 (2021)
10.1103/PhysRevD.103.054020
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We discuss whether the bound nature of multiquark states in quark models could benefit from relativistic effects on the kinetic energy operator. For mesons and baryons, relativistic corrections to the kinetic energy lead to lower energies, and thus call for a retuning of the parameters of the model. For multiquark states, as well as their respective thresholds, a comparison is made of the results obtained with non-relativistic and relativistic kinetic energy. It is found that the binding energy is lower in the relativistic case. In particular, $QQ\bar q\bar q$ tetraquarks with double heavy flavor become stable for a larger ratio of the heavy to light quark masses; and the all-heavy tetraquarks $QQ\bar Q\bar Q$ that are not stable in standard non-relativistic quark models remain unstable when a relativistic form of kinetic energy is adopted
[ { "created": "Wed, 3 Mar 2021 07:14:24 GMT", "version": "v1" } ]
2021-03-24
[ [ "Richard", "Jean-Marc", "" ], [ "Valcarce", "Alfredo", "" ], [ "Vijande", "Javier", "" ] ]
We discuss whether the bound nature of multiquark states in quark models could benefit from relativistic effects on the kinetic energy operator. For mesons and baryons, relativistic corrections to the kinetic energy lead to lower energies, and thus call for a retuning of the parameters of the model. For multiquark states, as well as their respective thresholds, a comparison is made of the results obtained with non-relativistic and relativistic kinetic energy. It is found that the binding energy is lower in the relativistic case. In particular, $QQ\bar q\bar q$ tetraquarks with double heavy flavor become stable for a larger ratio of the heavy to light quark masses; and the all-heavy tetraquarks $QQ\bar Q\bar Q$ that are not stable in standard non-relativistic quark models remain unstable when a relativistic form of kinetic energy is adopted
0902.0162
M. N. Rebelo
Gustavo C. Branco and M. N. Rebelo
Leptogenesis and Low-energy Observables
Invited talk presented by Gustavo C. Branco at NOW 2008: Neutrino Oscillation Workshop, 6-13 Sep 2008, Conca Specchiulla (Otranto), Lecce, Italy
Nucl.Phys.Proc.Suppl.188:325-328,2009
10.1016/j.nuclphysbps.2009.02.075
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the question of how to establish a connection between leptogenesis and low energy observables. We emphasize that such a connection only exists in the framework of flavour models. A particular example is the case of texture zeros in some of the Yukawa couplings.
[ { "created": "Sun, 1 Feb 2009 19:03:12 GMT", "version": "v1" } ]
2009-04-17
[ [ "Branco", "Gustavo C.", "" ], [ "Rebelo", "M. N.", "" ] ]
We address the question of how to establish a connection between leptogenesis and low energy observables. We emphasize that such a connection only exists in the framework of flavour models. A particular example is the case of texture zeros in some of the Yukawa couplings.
0711.1881
Matthias Burkardt
Matthias Burkardt
GPDs with $\zeta \neq 0$
4 pages
null
null
null
hep-ph
null
We revisit the light-cone wave function representation for generalized parton distributions with $\zeta\neq 0$. After translating the $t$-slope into a $\Delta_\perp^2$-slope, the two-dimensional Fourier transform of GPDs is interpreted as the transition matrix element as a function of the separation between the active quark and the center of momentum of the spectators. In the limit $x\to \zeta$ it is discussed how this information can be used to learn about the dependence of the mean separation between the active quark and the spectators on the momentum fraction carried by the active quark.
[ { "created": "Mon, 12 Nov 2007 22:24:36 GMT", "version": "v1" }, { "created": "Tue, 13 Nov 2007 21:33:53 GMT", "version": "v2" } ]
2007-11-14
[ [ "Burkardt", "Matthias", "" ] ]
We revisit the light-cone wave function representation for generalized parton distributions with $\zeta\neq 0$. After translating the $t$-slope into a $\Delta_\perp^2$-slope, the two-dimensional Fourier transform of GPDs is interpreted as the transition matrix element as a function of the separation between the active quark and the center of momentum of the spectators. In the limit $x\to \zeta$ it is discussed how this information can be used to learn about the dependence of the mean separation between the active quark and the spectators on the momentum fraction carried by the active quark.
1604.05746
Luca Di Luzio
Luca Di Luzio, Jernej F. Kamenik, Marco Nardecchia
Implications of perturbative unitarity for scalar di-boson resonance searches at LHC
34 pages, 9 figures. Revised version, to appear in EPJC. v3: mistake in Appendix A.2 corrected
null
null
IPPP/17/2
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the constraints implied by partial wave unitarity on new physics in the form of spin-zero di-boson resonances at LHC. We derive the scale where the effective description in terms of the SM supplemented by a single resonance is expected to break down depending on the resonance mass and signal cross-section. Likewise, we use unitarity arguments in order to set perturbativity bounds on renormalizable UV completions of the effective description. We finally discuss under which conditions scalar di-boson resonance signals can be accommodated within weakly-coupled models.
[ { "created": "Tue, 19 Apr 2016 20:58:56 GMT", "version": "v1" }, { "created": "Sun, 1 Jan 2017 22:49:12 GMT", "version": "v2" }, { "created": "Tue, 2 Apr 2019 07:35:23 GMT", "version": "v3" } ]
2019-04-03
[ [ "Di Luzio", "Luca", "" ], [ "Kamenik", "Jernej F.", "" ], [ "Nardecchia", "Marco", "" ] ]
We study the constraints implied by partial wave unitarity on new physics in the form of spin-zero di-boson resonances at LHC. We derive the scale where the effective description in terms of the SM supplemented by a single resonance is expected to break down depending on the resonance mass and signal cross-section. Likewise, we use unitarity arguments in order to set perturbativity bounds on renormalizable UV completions of the effective description. We finally discuss under which conditions scalar di-boson resonance signals can be accommodated within weakly-coupled models.
2112.02069
Rabindra N. Mohapatra
Rabindra N. Mohapatra and Nobuchika Okada
A Unified Model for Inflation, pseudo-Goldstone Dark Matter, Neutrino Mass and Baryogenesis
14 pages, no figures, references updated
null
10.1103/PhysRevD.105.035024
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a unified theory of inflation, neutrino mass, baryogenesis and dark matter where global lepton number symmetry and its breaking play a crucial role. The basic idea is to use a lepton number carrying complex scalar field as the inflaton as well as the field that implements Affleck-Dine (AD) leptogenesis. Dark matter is the massive majoron which is a pseudo-Goldstone boson, resulting from the spontaneous breaking of lepton number symmetry supplemented by explicit lepton number violation needed to implement AD leptogenesis. The magnitude of the resulting $n_B/s$ in the model is related to the mass of the pseudo-Goldstone dark matter, connecting two apparently disconnected cosmological observations. Inverse seesaw mechanism with lepton number breaking at low scale is crucial to prevent washout of the lepton asymmetry during the universe's evolution. The model seems to provide an economical solution to several puzzles of the standard model of particle physics and cosmology in one stroke.
[ { "created": "Fri, 3 Dec 2021 18:34:10 GMT", "version": "v1" }, { "created": "Wed, 8 Dec 2021 21:59:45 GMT", "version": "v2" } ]
2022-03-14
[ [ "Mohapatra", "Rabindra N.", "" ], [ "Okada", "Nobuchika", "" ] ]
We present a unified theory of inflation, neutrino mass, baryogenesis and dark matter where global lepton number symmetry and its breaking play a crucial role. The basic idea is to use a lepton number carrying complex scalar field as the inflaton as well as the field that implements Affleck-Dine (AD) leptogenesis. Dark matter is the massive majoron which is a pseudo-Goldstone boson, resulting from the spontaneous breaking of lepton number symmetry supplemented by explicit lepton number violation needed to implement AD leptogenesis. The magnitude of the resulting $n_B/s$ in the model is related to the mass of the pseudo-Goldstone dark matter, connecting two apparently disconnected cosmological observations. Inverse seesaw mechanism with lepton number breaking at low scale is crucial to prevent washout of the lepton asymmetry during the universe's evolution. The model seems to provide an economical solution to several puzzles of the standard model of particle physics and cosmology in one stroke.
hep-ph/9910490
null
Alekhin Sergey (IHEP, Protvino)
Value of $\alpha_s$ and high twists from combined analysis $e-\mu$ DIS data
Talk given on XI-th Recontres de Blois, ``Frontiers of Matter'', June 28-July 3, 1999, 3 pages, LATEX, 1 figure (EPS)
null
null
null
hep-ph
null
We perform a NLO QCD analysis of the combined SLAC-BCDMS-NMC-E665-H1-ZEUS data on inclusive deep inelastic cross section. Particular attention was paid to the extraction of strong coupling constant $\alpha_s$ and high twist (HT) contribution to the structure functions $F_2$ and $F_L$. It was shown that at small and moderate x there is a visible dependence of the extracted values of HT contribution to $F_2$ on the QCD renormalization scale, which indicates that in this region extracted HT can absorb NNLO QCD corrections. At larger x the dependence of HT on the renormalization scale is negligible and the influence of NNLO correction on their values should be less significant. The value of $\alpha_s(M_Z)=0.1159\pm0.0031$ (total) is obtained, where the error includes statistical, systematical and theoretical uncertainties.
[ { "created": "Tue, 26 Oct 1999 15:25:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sergey", "Alekhin", "", "IHEP, Protvino" ] ]
We perform a NLO QCD analysis of the combined SLAC-BCDMS-NMC-E665-H1-ZEUS data on inclusive deep inelastic cross section. Particular attention was paid to the extraction of strong coupling constant $\alpha_s$ and high twist (HT) contribution to the structure functions $F_2$ and $F_L$. It was shown that at small and moderate x there is a visible dependence of the extracted values of HT contribution to $F_2$ on the QCD renormalization scale, which indicates that in this region extracted HT can absorb NNLO QCD corrections. At larger x the dependence of HT on the renormalization scale is negligible and the influence of NNLO correction on their values should be less significant. The value of $\alpha_s(M_Z)=0.1159\pm0.0031$ (total) is obtained, where the error includes statistical, systematical and theoretical uncertainties.