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1401.7703
Peter Filip
Peter Filip
Magnetic Polarizability of Diquarks in Baryons
4 pages, 1 figure, contribution to XV Workshop on High Energy Spin Physics: DSPIN-13, October 8 - 12, 2013 (corrected misprints)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the response of diquark wave function in \Lambda-type baryons to strong magnetic fields. It is found that quantum state of J=0 diquark (ud) in the magnetic field changes due to magnetic polarizability, and constituent quarks in (ud) diquark become polarized. The phenomenon influences polarized quark distribution functions \Delta u(x) and \Delta d(x), which therefore may be sensitive to the internal electromagnetic fields in hypernuclei. We also speculate, that strange quark polarization in nucleon may originate from the interaction of virtual (ss') quark pairs with the intrinsic magnetic field of nucleon B $\approx$ 10^13 T.
[ { "created": "Wed, 29 Jan 2014 23:40:32 GMT", "version": "v1" }, { "created": "Tue, 4 Feb 2014 10:26:45 GMT", "version": "v2" } ]
2014-02-05
[ [ "Filip", "Peter", "" ] ]
We study the response of diquark wave function in \Lambda-type baryons to strong magnetic fields. It is found that quantum state of J=0 diquark (ud) in the magnetic field changes due to magnetic polarizability, and constituent quarks in (ud) diquark become polarized. The phenomenon influences polarized quark distribution functions \Delta u(x) and \Delta d(x), which therefore may be sensitive to the internal electromagnetic fields in hypernuclei. We also speculate, that strange quark polarization in nucleon may originate from the interaction of virtual (ss') quark pairs with the intrinsic magnetic field of nucleon B $\approx$ 10^13 T.
2009.01405
En Wang
Wei Hao, Guan-Ying Wang, En Wang, De-Min Li and Guan-Nan Li
Canonical interpretation of the $X(4140)$ state within the $^3P_0$ model
4 pages, 1 figure, 1 table, contribution to 18th International Conference on Hadron Spectroscopy and Structure (HADRON 2019)
Hadron Spectroscopy and Structure, pp. 771-774 (2020)
10.1142/9789811219313_0137
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, LHCb collaboration has confirmed the state $X(4140)$, with a much larger width $\Gamma= 83\pm 21^{+21}_{-14}$ MeV than the previous experimental measurements, which has confused the understanding of its nature. We have investigated the possibility of the $\chi_{c1}(3P)$ interpretation for the $X(4140)$, considering the mass and the strong decay properties.
[ { "created": "Thu, 3 Sep 2020 01:40:06 GMT", "version": "v1" } ]
2020-09-04
[ [ "Hao", "Wei", "" ], [ "Wang", "Guan-Ying", "" ], [ "Wang", "En", "" ], [ "Li", "De-Min", "" ], [ "Li", "Guan-Nan", "" ] ]
Recently, LHCb collaboration has confirmed the state $X(4140)$, with a much larger width $\Gamma= 83\pm 21^{+21}_{-14}$ MeV than the previous experimental measurements, which has confused the understanding of its nature. We have investigated the possibility of the $\chi_{c1}(3P)$ interpretation for the $X(4140)$, considering the mass and the strong decay properties.
hep-ph/9805228
Patrik Eden
Patrik Eden (1), Gosta Gustafson (1) ((1) Dept. of Ther. Phys., Lund University, Sweden)
Energy and Virtuality Scale Dependence in Quark and Gluon Jets
31 pages, 15 figures. Submitted to JHEP. Replaced with extensively rewritten version
JHEP 9809:015,1998
10.1088/1126-6708/1998/09/015
LU TP 98-11
hep-ph
null
We discuss some important issues concerning multiplicities in quark and gluon jets in e+e- annihilation. In QCD the properties of a jet in general depend on two scales, the energy and virtuality of the jet. Frequently theoretical predictions apply to a situation where these scales coincide, while for experimental data they are often different. Thus an analysis to extract e.g. the asymptotic multiplicity ratio CF/CA between quark and gluon jets, needs a carefully specified jet definition, together with a calculation of nonleading corrections to the multiplicity evolution. We propose methods to systematically study the separate dependence upon the two scales in experimental data and compare the results with theory. We present jet finding algorithms which corresponds well to the theoretically considered jets. We also show that recoil effects add corrections to the modified leading log approximation which are quantitatively important, though formally suppressed at high energies.
[ { "created": "Tue, 5 May 1998 16:30:55 GMT", "version": "v1" }, { "created": "Tue, 1 Sep 1998 16:56:38 GMT", "version": "v2" } ]
2016-09-06
[ [ "Eden", "Patrik", "" ], [ "Gustafson", "Gosta", "" ] ]
We discuss some important issues concerning multiplicities in quark and gluon jets in e+e- annihilation. In QCD the properties of a jet in general depend on two scales, the energy and virtuality of the jet. Frequently theoretical predictions apply to a situation where these scales coincide, while for experimental data they are often different. Thus an analysis to extract e.g. the asymptotic multiplicity ratio CF/CA between quark and gluon jets, needs a carefully specified jet definition, together with a calculation of nonleading corrections to the multiplicity evolution. We propose methods to systematically study the separate dependence upon the two scales in experimental data and compare the results with theory. We present jet finding algorithms which corresponds well to the theoretically considered jets. We also show that recoil effects add corrections to the modified leading log approximation which are quantitatively important, though formally suppressed at high energies.
hep-ph/9910480
Kunihiko Terasaki
K. Terasaki
Non-factorizable contribution in B decays
15 pages
null
10.1142/9789812791870_0025
YITP-99-65
hep-ph
null
Two body decays of B mesons are studied by decomposing their amplitude into a sum of factorizable and non-factorizable ones. The former is estimated by using a naive factorization while the latter is assumed to be dominated by dynamical contributions of various hadron states and is calculated by using a hard pion (or kaon) technique in the infinite momentum frame. Possible roles of the non-factorizable contributions are discussed by comparing the result with experiments.
[ { "created": "Tue, 26 Oct 1999 00:18:13 GMT", "version": "v1" } ]
2016-11-23
[ [ "Terasaki", "K.", "" ] ]
Two body decays of B mesons are studied by decomposing their amplitude into a sum of factorizable and non-factorizable ones. The former is estimated by using a naive factorization while the latter is assumed to be dominated by dynamical contributions of various hadron states and is calculated by using a hard pion (or kaon) technique in the infinite momentum frame. Possible roles of the non-factorizable contributions are discussed by comparing the result with experiments.
0710.5730
Jorge C. Romao
Jorge C. Romao
Supersymmetric Models for Neutrino Mass
6 pages, 18 Figures in Postscript. Based on a talk given at the "6th International Workshop on New Worlds in Astroparticle Physics", 6-8 September 2007, Faro, Portugal. To appear in the Proceedings. Uses the IEEEtran.cls LaTeX class
null
null
null
hep-ph
null
We review models for neutrino mass, with special emphasis in supersymmetric models where R-parity is broken either explicitly or spontaneously. The simplest unified extension of the MSSM with explicit bilinear R-parity violation provides a predictive scheme for neutrino masses and mixings which can account for the observed atmospheric and solar neutrino anomalies. Despite the smallness of neutrino masses R-parity violation is observable at present and future high-energy colliders, providing an unambiguous cross-check of the model. This model can be shown to be an effective model for the, more theoretically satisfying, spontaneous broken theory. The main difference in this last case is the appearance of a massless particle, the majoron, that can modify the decay modes of the Higgs boson, making it decay invisibly most of the time.
[ { "created": "Tue, 30 Oct 2007 18:44:27 GMT", "version": "v1" } ]
2007-10-31
[ [ "Romao", "Jorge C.", "" ] ]
We review models for neutrino mass, with special emphasis in supersymmetric models where R-parity is broken either explicitly or spontaneously. The simplest unified extension of the MSSM with explicit bilinear R-parity violation provides a predictive scheme for neutrino masses and mixings which can account for the observed atmospheric and solar neutrino anomalies. Despite the smallness of neutrino masses R-parity violation is observable at present and future high-energy colliders, providing an unambiguous cross-check of the model. This model can be shown to be an effective model for the, more theoretically satisfying, spontaneous broken theory. The main difference in this last case is the appearance of a massless particle, the majoron, that can modify the decay modes of the Higgs boson, making it decay invisibly most of the time.
hep-ph/0405179
Sandip Pakvasa
Sandip Pakvasa
Neutrino properties from high energy astrophysical neutrinos
12 pages, 1 figure. To appear in the Proceedings of the Fujihara Seminar "Neutrino Mass and See-Saw Mechanism", KEK 23-25 February 2004. To be published in Nucl. Phys.B(Proceedings Supplement)
Mod.Phys.Lett. A19 (2004) 1163-1169; Yad.Fiz. 67 (2004) 1179-1185
10.1134/1.1772452
UH-511-1051-04
hep-ph astro-ph hep-ex
null
It is shown how high energy neutrino beams from very distant sources can be utilised to learn about some properties of neutrinos such as lifetimes, mass hierarchy etc. Furthemore, even mixing elements such as U_e3 and the CPV phase in the neutrino mixing matrix can be measured in principle. Pseudo-Dirac mass differences as small as 10^-18 eV^2 can be probed as well.
[ { "created": "Wed, 19 May 2004 00:55:29 GMT", "version": "v1" } ]
2015-06-25
[ [ "Pakvasa", "Sandip", "" ] ]
It is shown how high energy neutrino beams from very distant sources can be utilised to learn about some properties of neutrinos such as lifetimes, mass hierarchy etc. Furthemore, even mixing elements such as U_e3 and the CPV phase in the neutrino mixing matrix can be measured in principle. Pseudo-Dirac mass differences as small as 10^-18 eV^2 can be probed as well.
0711.1977
Miguel Albaladejo
Miguel Albaladejo and Jose A. Oller and C\'andido Piqueras
S-wave meson scattering up to sqrt{s} < 2 GeV from chiral Lagrangians
4 pages. Talk given at 11th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2007), Julich, Germany, 10-14 Sep 2007
ECONF C070910:203,2007
null
null
hep-ph
null
The problem of scalar mesons still remains a challenging puzzle, for which we do not even know which are the right pieces to set up. The proliferation of resonances (some of them are very broad and appear on top of hadronic thresholds) and of coupled channels that interact strongly among each other makes the study of this sector a hard task. Our objective is the study of the strongly interacting mesons in coupled channels with quantum numbers J^{PC} = 0^{++} and I=0 and I=1/2, up to a center of mass energy sqrt{s} < 2 GeV. Our framework is based on Unitary Chiral Perturbation Theory. We include for I=0 the channels: \pi\pi, K\bar{K}, \eta\eta, \sigma\sigma, \eta\eta', \rho\rho, \omega\omega, \eta'\eta', \omega\phi, \phi\phi, K^\ast \bar{K}^\ast, a_1(1260)\pi and \pi^{\star}(1300)\pi. In addition, and in order to constrain our fits, we also study the I=1/2, 3/2 channels given by K\pi, K\eta and K\eta'. We finally present the resonant content of our fits with the $\sigma$, $f_0(980)$, $f_0(1310)$, $f_(1500)$, $f_0(1710)$ and $f_0(1790)$.
[ { "created": "Tue, 13 Nov 2007 14:50:10 GMT", "version": "v1" }, { "created": "Wed, 14 Nov 2007 09:20:32 GMT", "version": "v2" } ]
2011-03-31
[ [ "Albaladejo", "Miguel", "" ], [ "Oller", "Jose A.", "" ], [ "Piqueras", "Cándido", "" ] ]
The problem of scalar mesons still remains a challenging puzzle, for which we do not even know which are the right pieces to set up. The proliferation of resonances (some of them are very broad and appear on top of hadronic thresholds) and of coupled channels that interact strongly among each other makes the study of this sector a hard task. Our objective is the study of the strongly interacting mesons in coupled channels with quantum numbers J^{PC} = 0^{++} and I=0 and I=1/2, up to a center of mass energy sqrt{s} < 2 GeV. Our framework is based on Unitary Chiral Perturbation Theory. We include for I=0 the channels: \pi\pi, K\bar{K}, \eta\eta, \sigma\sigma, \eta\eta', \rho\rho, \omega\omega, \eta'\eta', \omega\phi, \phi\phi, K^\ast \bar{K}^\ast, a_1(1260)\pi and \pi^{\star}(1300)\pi. In addition, and in order to constrain our fits, we also study the I=1/2, 3/2 channels given by K\pi, K\eta and K\eta'. We finally present the resonant content of our fits with the $\sigma$, $f_0(980)$, $f_0(1310)$, $f_(1500)$, $f_0(1710)$ and $f_0(1790)$.
0805.4802
Carlo Oleari
Simone Alioli, Paolo Nason, Carlo Oleari, Emanuele Re
NLO vector-boson production matched with shower in POWHEG
35 pages, 34 figures
JHEP0807:060,2008
10.1088/1126-6708/2008/07/060
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a next-to-leading-order calculation of W/Z production interfaced to shower Monte Carlo, implemented according to the POWHEG method. Finite width effects, Z/gamma interference and angular correlations of decay products are included. A detailed comparison with MC@NLO and PYTHIA is carried out.
[ { "created": "Fri, 30 May 2008 16:51:15 GMT", "version": "v1" } ]
2008-11-26
[ [ "Alioli", "Simone", "" ], [ "Nason", "Paolo", "" ], [ "Oleari", "Carlo", "" ], [ "Re", "Emanuele", "" ] ]
We present a next-to-leading-order calculation of W/Z production interfaced to shower Monte Carlo, implemented according to the POWHEG method. Finite width effects, Z/gamma interference and angular correlations of decay products are included. A detailed comparison with MC@NLO and PYTHIA is carried out.
hep-ph/0007258
Eugene Levin
E. Gotsman (Tel Aviv U.),E. Levin (Tel Aviv U./BNL),U. Maor (Tel Aviv U.) L.McLerran(BNL) and K.Tuchin(Tel Aviv U.)
Higher twists and maxima for DIS on nuclei in high density QCD region
16 pages of Latex file,8 figures in eps files
Nucl.Phys. A683 (2001) 383-405
10.1016/S0375-9474(00)00464-4
TAUP-2638-200,BNL-NT-00/19
hep-ph
null
We show that the ratio of different structure functions have a maximum which depends on $x_B$ and $A$. We argue that these maxima are proportional to the saturation scale. The analysis of leading and higher twist contributions for different observables is given with the aim of determining the kinematic region where high parton density effects could be seen experimentally.
[ { "created": "Mon, 24 Jul 2000 12:05:40 GMT", "version": "v1" }, { "created": "Wed, 26 Jul 2000 07:40:20 GMT", "version": "v2" } ]
2009-10-31
[ [ "Gotsman", "E.", "", "Tel Aviv U." ], [ "Levin", "E.", "", "Tel Aviv U./BNL" ], [ "Maor", "U.", "", "Tel Aviv\n U." ], [ "McLerran", "L.", "", "BNL" ], [ "Tuchin", "K.", "", "Tel Aviv U." ] ]
We show that the ratio of different structure functions have a maximum which depends on $x_B$ and $A$. We argue that these maxima are proportional to the saturation scale. The analysis of leading and higher twist contributions for different observables is given with the aim of determining the kinematic region where high parton density effects could be seen experimentally.
0802.4216
V. Gogohia
V. Gogokhia
The color gauge invariance and a possible origin of the Jaffe-Witten mass gap in QCD
19 pages, no tables, no figures
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The physical meaning of a mass gap introduced by Jaffe and Witten is to be responsible for the large-scale (low-energy/momentum), i.e., the non-perturbative structure of the true QCD vacuum. In order to make the existence of a mass gap pefrectly clear it is defined as the difference between the regularized full gluon self-energy and its subtracted (also regularized) counterpart. The mass gap is mainly generated by the nonlinear interaction of massless gluon modes. A self-consistent violation of SU(3) color gauge invariance/symmetry is duscussed in order to realize a mass gap in QCD. For this purpose, we propose not to impose the transversality condition on the full gluon self-energy, while restoring the transversality of the full gluon propagtor relevant for the non-perturbative QCD at the final stage. At the same time, the Slavnov-Taylor identity for the full gluon propagator is always preserved. All this allows one to establish the general structure of the full gluon propagator in the presence of a mass gap. In this case, two independent types of formal solutions for the full gluon propagator have been established. The nonlinear iteration solution at which the gluons remain massless is explicitly present. The existence of the solution with an effective gluon mass is also demonstrated.
[ { "created": "Thu, 28 Feb 2008 14:55:25 GMT", "version": "v1" } ]
2008-03-05
[ [ "Gogokhia", "V.", "" ] ]
The physical meaning of a mass gap introduced by Jaffe and Witten is to be responsible for the large-scale (low-energy/momentum), i.e., the non-perturbative structure of the true QCD vacuum. In order to make the existence of a mass gap pefrectly clear it is defined as the difference between the regularized full gluon self-energy and its subtracted (also regularized) counterpart. The mass gap is mainly generated by the nonlinear interaction of massless gluon modes. A self-consistent violation of SU(3) color gauge invariance/symmetry is duscussed in order to realize a mass gap in QCD. For this purpose, we propose not to impose the transversality condition on the full gluon self-energy, while restoring the transversality of the full gluon propagtor relevant for the non-perturbative QCD at the final stage. At the same time, the Slavnov-Taylor identity for the full gluon propagator is always preserved. All this allows one to establish the general structure of the full gluon propagator in the presence of a mass gap. In this case, two independent types of formal solutions for the full gluon propagator have been established. The nonlinear iteration solution at which the gluons remain massless is explicitly present. The existence of the solution with an effective gluon mass is also demonstrated.
hep-ph/0702205
Chihiro Sasaki
M. Harada (Nagoya Univ.), C. Sasaki (GSI)
Thermal Dilepton Production from Dropping rho in the Vector Manifestation
6 pages, 2 figures, contribution to the proceedings of the 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM2006), November 14-20 2006, Shanghai, China
Int.J.Mod.Phys.E16:2143-2148,2007
10.1142/S0218301307007593
null
hep-ph nucl-th
null
We study the pion electromagnetic form factor and the dilepton production rate in hot matter based on the vector manifestation (VM) of chiral symmetry in which the massless vector meson becomes the chiral partner of the pion, giving a theoretical framework of the dropping $\rho$ \^^ a la Brown-Rho scaling. The VM predicts a strong violation of the vector dominance (VD) near the phase transition point associated with the dropping $\rho$. We present the effect of the VD violation to the dilepton production rate and make a comparison to the one predicted by assuming the VD together with the dropping $\rho$.
[ { "created": "Tue, 20 Feb 2007 18:17:17 GMT", "version": "v1" } ]
2008-11-26
[ [ "Harada", "M.", "", "Nagoya Univ." ], [ "Sasaki", "C.", "", "GSI" ] ]
We study the pion electromagnetic form factor and the dilepton production rate in hot matter based on the vector manifestation (VM) of chiral symmetry in which the massless vector meson becomes the chiral partner of the pion, giving a theoretical framework of the dropping $\rho$ \^^ a la Brown-Rho scaling. The VM predicts a strong violation of the vector dominance (VD) near the phase transition point associated with the dropping $\rho$. We present the effect of the VD violation to the dilepton production rate and make a comparison to the one predicted by assuming the VD together with the dropping $\rho$.
1911.12591
Wolfgang Lucha
Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian
Tetraquark Properties at Large $N_{\rm c}$
5 pages, 4 figures, talk presented at "Light Cone 2019 - QCD on the light cone: from hadrons to heavy ions - LC2019" (16 - 20 September 2019, Palaiseau, France)
null
null
HEPHY-PUB 1021/19 (2019)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Considering quantum chromodynamics in the consistent limit of simultaneous correlated increase of the number of colours, $N_{\rm c}$, beyond bounds and decrease of the strong coupling to zero allows for solid statements about qualitative features of the class of "truly exotic" tetraquark mesons carrying four mutually distinct quark flavours. Consistency criteria extracted from correlation functions for two-ordinary-meson scattering suggest the existence of more than one such tetraquarks, at least, of two tetraquarks of identical quark-flavour content and large-$N_{\rm c}$ behaviour of the total decay widths but differing in, and hence discriminable by, their predominant decay modes into two conventional mesons. This pairwise appearance is in conflict with the unique variant of such a four-quark bound state arising from the binding of diquark and antidiquark to a tetraquark by the strong interactions.
[ { "created": "Thu, 28 Nov 2019 08:41:08 GMT", "version": "v1" }, { "created": "Sun, 1 Mar 2020 12:02:15 GMT", "version": "v2" } ]
2020-03-03
[ [ "Lucha", "Wolfgang", "" ], [ "Melikhov", "Dmitri", "" ], [ "Sazdjian", "Hagop", "" ] ]
Considering quantum chromodynamics in the consistent limit of simultaneous correlated increase of the number of colours, $N_{\rm c}$, beyond bounds and decrease of the strong coupling to zero allows for solid statements about qualitative features of the class of "truly exotic" tetraquark mesons carrying four mutually distinct quark flavours. Consistency criteria extracted from correlation functions for two-ordinary-meson scattering suggest the existence of more than one such tetraquarks, at least, of two tetraquarks of identical quark-flavour content and large-$N_{\rm c}$ behaviour of the total decay widths but differing in, and hence discriminable by, their predominant decay modes into two conventional mesons. This pairwise appearance is in conflict with the unique variant of such a four-quark bound state arising from the binding of diquark and antidiquark to a tetraquark by the strong interactions.
2008.02643
Andreas Crivellin
Andreas Crivellin, Dario Mueller and Francesco Saturnino
Correlating $h\to\mu^+\mu^-$ to the Anomalous Magnetic Moment of the Muon via Leptoquarks
8 pages, 3 figures, g-2 updated, EFT discussion added, version accepted for publication in PRL
Phys. Rev. Lett. 127, 021801 (2021)
10.1103/PhysRevLett.127.021801
CERN-TH-2020-134, PSI-PR-20-12, ZU-TH 28/20
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, both ATLAS and CMS measured the decay $h\to\mu^+\mu^-$, finding a signal strength with respect to the Standard Model expectation of $1.2\pm0.6$ and $1.19\substack{+0.41+0.17\\-0.39 -0.16}$, respectively. This provides, for the first time, evidence that the Standard Model Higgs couples to second generation fermions. This measurement is particularly interesting in the context of the intriguing hints for lepton flavor universality violation, accumulated within recent years, as new physics explanations could also be tested in the $h\to\mu^{+}\mu^{-}$ decay mode. Leptoquarks are prime candidates to account for the flavor anomalies. In particular, they can provide the necessary chiral enhancement (by a factor $m_t/m_\mu$) to address $a_\mu$ with TeV scale new physics. In this letter we point out that such explanations of $a_\mu$ also lead to enhanced effects in $h\to\mu^+\mu^-$ and we examine the correlations between $h\to\mu^+\mu^-$ and $a_\mu$ within leptoquark models. We find that the effect in the branching ratio of $h\to\mu^+\mu^-$ ranges from several percent up to a factor three, if one aims at accounting for $a_\mu$ at the $2\,\sigma$ level. Hence, the new ATLAS and CMS measurements already provide important constraints on the parameter space, rule out specific $a_\mu$ explanations and will be very important to test the flavor anomalies in the future.
[ { "created": "Thu, 6 Aug 2020 13:24:38 GMT", "version": "v1" }, { "created": "Thu, 3 Jun 2021 10:04:09 GMT", "version": "v2" } ]
2021-07-14
[ [ "Crivellin", "Andreas", "" ], [ "Mueller", "Dario", "" ], [ "Saturnino", "Francesco", "" ] ]
Recently, both ATLAS and CMS measured the decay $h\to\mu^+\mu^-$, finding a signal strength with respect to the Standard Model expectation of $1.2\pm0.6$ and $1.19\substack{+0.41+0.17\\-0.39 -0.16}$, respectively. This provides, for the first time, evidence that the Standard Model Higgs couples to second generation fermions. This measurement is particularly interesting in the context of the intriguing hints for lepton flavor universality violation, accumulated within recent years, as new physics explanations could also be tested in the $h\to\mu^{+}\mu^{-}$ decay mode. Leptoquarks are prime candidates to account for the flavor anomalies. In particular, they can provide the necessary chiral enhancement (by a factor $m_t/m_\mu$) to address $a_\mu$ with TeV scale new physics. In this letter we point out that such explanations of $a_\mu$ also lead to enhanced effects in $h\to\mu^+\mu^-$ and we examine the correlations between $h\to\mu^+\mu^-$ and $a_\mu$ within leptoquark models. We find that the effect in the branching ratio of $h\to\mu^+\mu^-$ ranges from several percent up to a factor three, if one aims at accounting for $a_\mu$ at the $2\,\sigma$ level. Hence, the new ATLAS and CMS measurements already provide important constraints on the parameter space, rule out specific $a_\mu$ explanations and will be very important to test the flavor anomalies in the future.
hep-ph/0506298
Marco Cirelli
Marco Cirelli, Nicolao Fornengo, Teresa Montaruli, Igor Sokalski, Alessandro Strumia, Francesco Vissani
Spectra of neutrinos from dark matter annihilations
40 pages, 15 figures and 4 tables; v2: typos corrected, references added, matches published version; v3: a numerical factor corrected, conclusions unchanged; v4: a small numerical error corrected, conclusions unchanged; v5: another small bug corrected, conclusions unchanged. Updated results available online as indicated in ref. [30].
Nucl.Phys.B727:99-138,2005; Erratum-ibid.B790:338-344,2008
10.1016/j.nuclphysb.2005.08.017 10.1016/j.nuclphysb.2007.10.001
DFTT12/2005, IFUP-TH/2005-13
hep-ph astro-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the fluxes of neutrinos from annihilations of dark matter particles in the Sun and the Earth. We give the spectra of all neutrino flavors for the main known annihilation channels: nu-antinu, b-bbar, tau-taubar, c-cbar, light quarks, ZZ, W^+W^-. We present the appropriate formalism for computing the combined effect of oscillations, absorptions, nu_tau-regeneration. Total rates are modified by an O(0.1--10) factor, comparable to astrophysical uncertainties, that instead negligibly affect the spectra. We then calculate different signal topologies in neutrino telescopes: through-going muons, contained muons, showers, and study their capabilities to discriminate a dark matter signal from backgrounds. We finally discuss how measuring the neutrino spectra can allow to reconstruct the fundamental properties of the dark matter: its mass and its annihilation branching ratios.
[ { "created": "Wed, 29 Jun 2005 17:04:57 GMT", "version": "v1" }, { "created": "Fri, 4 Nov 2005 14:31:49 GMT", "version": "v2" }, { "created": "Fri, 27 Jul 2007 14:08:17 GMT", "version": "v3" }, { "created": "Thu, 27 Sep 2007 14:21:18 GMT", "version": "v4" }, { "cr...
2014-11-18
[ [ "Cirelli", "Marco", "" ], [ "Fornengo", "Nicolao", "" ], [ "Montaruli", "Teresa", "" ], [ "Sokalski", "Igor", "" ], [ "Strumia", "Alessandro", "" ], [ "Vissani", "Francesco", "" ] ]
We study the fluxes of neutrinos from annihilations of dark matter particles in the Sun and the Earth. We give the spectra of all neutrino flavors for the main known annihilation channels: nu-antinu, b-bbar, tau-taubar, c-cbar, light quarks, ZZ, W^+W^-. We present the appropriate formalism for computing the combined effect of oscillations, absorptions, nu_tau-regeneration. Total rates are modified by an O(0.1--10) factor, comparable to astrophysical uncertainties, that instead negligibly affect the spectra. We then calculate different signal topologies in neutrino telescopes: through-going muons, contained muons, showers, and study their capabilities to discriminate a dark matter signal from backgrounds. We finally discuss how measuring the neutrino spectra can allow to reconstruct the fundamental properties of the dark matter: its mass and its annihilation branching ratios.
1006.3756
Sovan Chakraborty
Sovan Chakraborty, Sandhya Choubey and Kamales Kar
On the Observability of Collective Flavor Oscillations in Diffuse Supernova Neutrino Background
9 pages, 5 figures, version matches published version in Phys.Lett.B
Phys.Lett.B702:209-215,2011
10.1016/j.physletb.2011.06.089
null
hep-ph astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Collective flavor oscillations are known to bring multiple splits in the supernova (SN) neutrino and antineutrino spectra. These spectral splits depend not only on the mass hierarchy of the neutrinos but also on the initial relative flux composition. Observation of spectral splits in a future galactic supernova signal is expected to throw light on the mass hierarchy pattern of the neutrinos. However, since the Diffuse Supernova Neutrino Background (DSNB) comprises of a superposition of neutrino fluxes from all past supernovae, and since different supernovae are expected to have slightly different initial fluxes, it is pertinent to check if the hierarchy dependent signature of collective oscillations can survive this averaging of the flux spectra. Since the actual distribution of SN with initial relative flux spectra of the neutrinos and antineutrinos is unknown, we assume a log-normal distribution for them. We study the dependence of the hierarchy sensitivity to the mean and variance of the log-normal distribution function. We find that the hierarchy sensitivity depends crucially on the mean value of the relative initial luminosity. The effect of the width is to reduce the hierarchy sensitivity for all values of the mean initial relative luminosity. We find that in the very small mixing angle ($\theta_{13}$) limit considering only statistical errors even for very moderate values of variance, there is almost no detectable hierarchy sensitivity if the mean relative luminosities of $\nu_e$ and $\bar\nu_e$ are greater than 1.
[ { "created": "Fri, 18 Jun 2010 17:33:06 GMT", "version": "v1" }, { "created": "Mon, 11 Oct 2010 08:47:32 GMT", "version": "v2" }, { "created": "Fri, 12 Aug 2011 14:39:30 GMT", "version": "v3" } ]
2011-08-15
[ [ "Chakraborty", "Sovan", "" ], [ "Choubey", "Sandhya", "" ], [ "Kar", "Kamales", "" ] ]
Collective flavor oscillations are known to bring multiple splits in the supernova (SN) neutrino and antineutrino spectra. These spectral splits depend not only on the mass hierarchy of the neutrinos but also on the initial relative flux composition. Observation of spectral splits in a future galactic supernova signal is expected to throw light on the mass hierarchy pattern of the neutrinos. However, since the Diffuse Supernova Neutrino Background (DSNB) comprises of a superposition of neutrino fluxes from all past supernovae, and since different supernovae are expected to have slightly different initial fluxes, it is pertinent to check if the hierarchy dependent signature of collective oscillations can survive this averaging of the flux spectra. Since the actual distribution of SN with initial relative flux spectra of the neutrinos and antineutrinos is unknown, we assume a log-normal distribution for them. We study the dependence of the hierarchy sensitivity to the mean and variance of the log-normal distribution function. We find that the hierarchy sensitivity depends crucially on the mean value of the relative initial luminosity. The effect of the width is to reduce the hierarchy sensitivity for all values of the mean initial relative luminosity. We find that in the very small mixing angle ($\theta_{13}$) limit considering only statistical errors even for very moderate values of variance, there is almost no detectable hierarchy sensitivity if the mean relative luminosities of $\nu_e$ and $\bar\nu_e$ are greater than 1.
2205.13550
Joel Jones-Perez
F. Delgado, L. Duarte, J. Jones-Perez, C. Manrique-Chavil, S. Pe\~na
Assessment of the Dimension-5 Seesaw Portal and Impact of Exotic Higgs Decays on Non-Pointing Photon Searches
42 pages, 9 figures, 3 appendices; v2: improved discussion, results unchanged. Version accepted for publication in JHEP
null
10.1007/JHEP09(2022)079
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Dimension-5 Seesaw Portal is a Type-I Seesaw model extended by $d=5$ operators involving the sterile neutrino states, leading to new interactions between all neutrinos and the Standard Model neutral bosons. In this work we focus primarily on the implications of these new operators at the GeV-scale. In particular, we recalculate the heavy neutrino full decay width, up to three-body decays. We also review bounds on the dipole operator, and revisit LEP constraints on its coefficient. Finally, we turn to heavy neutrino pair production from Higgs decays, where the former are long-lived and disintegrate into a photon and a light neutrino. We probe this process by recasting two ATLAS searches for non-pointing photons, showing the expected event distribution in terms of arrival time $t_\gamma$ and pointing variable $|\Delta z_\gamma|$.
[ { "created": "Thu, 26 May 2022 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 15 Aug 2022 15:25:06 GMT", "version": "v2" } ]
2022-09-28
[ [ "Delgado", "F.", "" ], [ "Duarte", "L.", "" ], [ "Jones-Perez", "J.", "" ], [ "Manrique-Chavil", "C.", "" ], [ "Peña", "S.", "" ] ]
The Dimension-5 Seesaw Portal is a Type-I Seesaw model extended by $d=5$ operators involving the sterile neutrino states, leading to new interactions between all neutrinos and the Standard Model neutral bosons. In this work we focus primarily on the implications of these new operators at the GeV-scale. In particular, we recalculate the heavy neutrino full decay width, up to three-body decays. We also review bounds on the dipole operator, and revisit LEP constraints on its coefficient. Finally, we turn to heavy neutrino pair production from Higgs decays, where the former are long-lived and disintegrate into a photon and a light neutrino. We probe this process by recasting two ATLAS searches for non-pointing photons, showing the expected event distribution in terms of arrival time $t_\gamma$ and pointing variable $|\Delta z_\gamma|$.
hep-ph/0112302
Alessandro Strumia
S. Davidson, S. Forte, P. Gambino, N. Rius, A. Strumia
Old and new physics interpretations of the NuTeV anomaly
22 pages, 4 figures. Final version; note added about oscillations. Version 4: note added at page 20 (not present in the published version), about QCD interpretations of the NuTeV anomaly
JHEP 0202:037,2002
10.1088/1126-6708/2002/02/037
CERN-TH/2001-366, IFUP-TH/2001-41, IFIC/01-69, FTUV-01-1217, RM3-TH/2001-17
hep-ph
null
We discuss whether the NuTeV anomaly can be explained, compatibly with all other data, by QCD effects (maybe, if the strange sea is asymmetric, or there is a tiny violation of isospin), new physics in propagators or couplings of the vector bosons (not really), loops of supersymmetric particles (no), dimension six operators (yes, for one specific SU(2)-invariant operator), leptoquarks (not in a minimal way), extra U(1) gauge bosons (maybe: an unmixed Z' coupled to B-3L_mu also increases the muon g-2 by about 10^{-9} and gives a `burst' to cosmic rays above the GZK cutoff).
[ { "created": "Fri, 21 Dec 2001 17:54:42 GMT", "version": "v1" }, { "created": "Fri, 18 Jan 2002 16:47:51 GMT", "version": "v2" }, { "created": "Fri, 1 Mar 2002 12:53:29 GMT", "version": "v3" }, { "created": "Thu, 27 Jun 2002 12:41:46 GMT", "version": "v4" } ]
2009-11-07
[ [ "Davidson", "S.", "" ], [ "Forte", "S.", "" ], [ "Gambino", "P.", "" ], [ "Rius", "N.", "" ], [ "Strumia", "A.", "" ] ]
We discuss whether the NuTeV anomaly can be explained, compatibly with all other data, by QCD effects (maybe, if the strange sea is asymmetric, or there is a tiny violation of isospin), new physics in propagators or couplings of the vector bosons (not really), loops of supersymmetric particles (no), dimension six operators (yes, for one specific SU(2)-invariant operator), leptoquarks (not in a minimal way), extra U(1) gauge bosons (maybe: an unmixed Z' coupled to B-3L_mu also increases the muon g-2 by about 10^{-9} and gives a `burst' to cosmic rays above the GZK cutoff).
2110.10432
Wang Yuanyuan
Yuanyuan Wang and Shinya Matsuzaki
Axial inverse magnetic catalysis
12 pages, 8 figures
Phys.Rev.D 105 (2022) 7, 074015
10.1103/PhysRevD.105.074015
null
hep-ph hep-lat nucl-th
http://creativecommons.org/licenses/by/4.0/
We find that the inverse magnetic catalysis for $U(1)$ axial symmetry (AIMC: axial inverse magnetic catalysis) can emerge around the chiral crossover regime in the thermomagnetic QCD with 2 + 1 flavors at physical point. This phenomenon can be correlated with the IMC for the chiral $SU(2)_L \times SU(2)_R$ symmetry (CIMC: chiral IMC). We explicitly observe the AIMC based on a Nambu-Jona-Lasinio model with 2 + 1 quark flavors, where introduced anomalous magnetic moments of the quarks play the essential role to drive both the CIMC and AIMC. Our finding is shortly testable on lattices. Possible phenomenological and cosmological implications are also briefly addressed.
[ { "created": "Wed, 20 Oct 2021 08:58:33 GMT", "version": "v1" }, { "created": "Wed, 27 Oct 2021 09:37:55 GMT", "version": "v2" }, { "created": "Thu, 21 Apr 2022 14:35:47 GMT", "version": "v3" } ]
2022-04-22
[ [ "Wang", "Yuanyuan", "" ], [ "Matsuzaki", "Shinya", "" ] ]
We find that the inverse magnetic catalysis for $U(1)$ axial symmetry (AIMC: axial inverse magnetic catalysis) can emerge around the chiral crossover regime in the thermomagnetic QCD with 2 + 1 flavors at physical point. This phenomenon can be correlated with the IMC for the chiral $SU(2)_L \times SU(2)_R$ symmetry (CIMC: chiral IMC). We explicitly observe the AIMC based on a Nambu-Jona-Lasinio model with 2 + 1 quark flavors, where introduced anomalous magnetic moments of the quarks play the essential role to drive both the CIMC and AIMC. Our finding is shortly testable on lattices. Possible phenomenological and cosmological implications are also briefly addressed.
2306.08038
Mathias Pierre
Marcos A. G. Garcia, Mathias Pierre
Reheating after Inflaton Fragmentation
29 pages, 9 figures; v2 matches version published in JCAP
null
null
DESY-23-075
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
In the presence of self-interactions, the post-inflationary evolution of the inflaton field is driven into the non-linear regime by the resonant growth of its fluctuations. The once spatially homogeneous coherent inflaton is converted into a collection of inflaton particles with non-vanishing momentum. Fragmentation significantly alters the energy transfer rate to the inflaton's offspring during the reheating epoch. In this work we introduce a formalism to quantify the effect of fragmentation on particle production rates, and determine the evolution of the inflaton and radiation energy densities, including the corresponding reheating temperatures. For an inflaton potential with a quartic minimum, we find that the efficiency of reheating is drastically diminished after backreaction, yet it can lead to temperatures above the big bang nucleosynthesis limit for sufficiently large couplings. In addition, we use a lattice simulation to estimate the spectrum of induced gravitational waves, sourced by the scalar inhomogeneities, and discuss detectability prospects. We find that a Boltzmann approach allows to accurately predict some of the main features of this spectrum.
[ { "created": "Tue, 13 Jun 2023 18:00:07 GMT", "version": "v1" }, { "created": "Tue, 7 Nov 2023 10:04:09 GMT", "version": "v2" } ]
2023-11-08
[ [ "Garcia", "Marcos A. G.", "" ], [ "Pierre", "Mathias", "" ] ]
In the presence of self-interactions, the post-inflationary evolution of the inflaton field is driven into the non-linear regime by the resonant growth of its fluctuations. The once spatially homogeneous coherent inflaton is converted into a collection of inflaton particles with non-vanishing momentum. Fragmentation significantly alters the energy transfer rate to the inflaton's offspring during the reheating epoch. In this work we introduce a formalism to quantify the effect of fragmentation on particle production rates, and determine the evolution of the inflaton and radiation energy densities, including the corresponding reheating temperatures. For an inflaton potential with a quartic minimum, we find that the efficiency of reheating is drastically diminished after backreaction, yet it can lead to temperatures above the big bang nucleosynthesis limit for sufficiently large couplings. In addition, we use a lattice simulation to estimate the spectrum of induced gravitational waves, sourced by the scalar inhomogeneities, and discuss detectability prospects. We find that a Boltzmann approach allows to accurately predict some of the main features of this spectrum.
hep-ph/9906413
Tomislav Prokopec
Michael Joyce, Kimmo Kainulainen and Tomislav Prokopec
Quantum Boltzmann equations for mixing scalar fields
Proceedings from SEWM-98, Copenhagen and NW-98, Faro
null
null
NBI-HE-99-19, NORDITA-99/39 HE
hep-ph cond-mat.stat-mech hep-th nucl-th
null
We report on a work in progress, whose goal is a systematic field theoretical derivation of the quantum transport equations for baryon production in the electroweak plasma at a first order phase transition in the limit of slowly varying background fields (thick wall limit). We start with the Schwinger-Dyson equations for the two point Green function written in the closed time contour (CTC) formalism. The quantum Boltzmann equations for the density matrix arise when the SD-equations are expanded to the first order in the gradients in the on-shell limit. In this paper we consider only scalar fields, but the formalism can easily be extended to fermions.
[ { "created": "Thu, 17 Jun 1999 13:54:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Joyce", "Michael", "" ], [ "Kainulainen", "Kimmo", "" ], [ "Prokopec", "Tomislav", "" ] ]
We report on a work in progress, whose goal is a systematic field theoretical derivation of the quantum transport equations for baryon production in the electroweak plasma at a first order phase transition in the limit of slowly varying background fields (thick wall limit). We start with the Schwinger-Dyson equations for the two point Green function written in the closed time contour (CTC) formalism. The quantum Boltzmann equations for the density matrix arise when the SD-equations are expanded to the first order in the gradients in the on-shell limit. In this paper we consider only scalar fields, but the formalism can easily be extended to fermions.
hep-ph/9504356
null
M.A.Braun
The photon-photon interaction at low $x$ in the theory of reggeized gluons with a running coupling and $N_{c}\to\infty$
12 pages, LATEX
Phys.Lett. B357 (1995) 138-144
10.1016/0370-2693(95)00867-K
SPbU-IP-1995/7
hep-ph
null
The forward elastic amplitude for scattering of real and weakly virtual photons is studied in the framework of the theory of reggeized gluons, with large $N_{c}$ and a running coupling constant introduced in the manner which preserves the bootstrap condition. Transition from a single to multiple pomeron exchanges is observed as $x$ gets smaller. For very low $x$ the amplitude aquires an eikonal form. The photon structure function reveals a strong violation of scaling: it grows as $Q^{2}$. As a function of $x$ it behaves as $(\ln(1/x)\ln\ln(1/x))^{2}$. Correspondingly the cross-section for physical photons grows with energy as $(\ln s\ln\ln s)^{2}$. Hadronic structure functions and cross-sections are also briefly discussed.
[ { "created": "Fri, 21 Apr 1995 08:07:32 GMT", "version": "v1" } ]
2009-10-28
[ [ "Braun", "M. A.", "" ] ]
The forward elastic amplitude for scattering of real and weakly virtual photons is studied in the framework of the theory of reggeized gluons, with large $N_{c}$ and a running coupling constant introduced in the manner which preserves the bootstrap condition. Transition from a single to multiple pomeron exchanges is observed as $x$ gets smaller. For very low $x$ the amplitude aquires an eikonal form. The photon structure function reveals a strong violation of scaling: it grows as $Q^{2}$. As a function of $x$ it behaves as $(\ln(1/x)\ln\ln(1/x))^{2}$. Correspondingly the cross-section for physical photons grows with energy as $(\ln s\ln\ln s)^{2}$. Hadronic structure functions and cross-sections are also briefly discussed.
2310.00043
Ryan Plestid
Richard J. Hill and Ryan Plestid and Jure Zupan
Searching for new physics at $\mu\rightarrow e$ facilities with $\mu^+$ and $\pi^+$ decays at rest
New projections for COMET, updated references and figures. Typos fixed
null
null
FERMILAB-PUB-23-287-T, CALT-TH/2023-017
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We investigate the ability of $\mu\rightarrow e$ facilities, Mu2e and COMET, to probe, or discover, new physics with their detector validation datasets. The validation of the detector response may be performed using a dedicated run with $\mu^+$, collecting data below the Michel edge, $E_e\lesssim 52$ MeV; an alternative strategy using $\pi^+\rightarrow e^+ \nu_e$ may also be considered. We focus primarily on a search for a monoenergetic $e^+$ produced via two-body decays $\mu^+ \rightarrow e^+ X$ or $\pi^+\rightarrow e^+X$, with $X$ a light new physics particle. Mu2e can potentially explore new parameter space beyond present astrophysical and laboratory constraints for a set of well motivated models including: axion like particles with flavor violating couplings ($\mu^+ \rightarrow e^+ a$), massive $Z'$ bosons ($\mu^+ \rightarrow Z' e^+$), and heavy neutral leptons ($\pi^+\rightarrow e^+N$). The projected sensitivities presented herein can be achieved in a matter of days.
[ { "created": "Fri, 29 Sep 2023 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 16 Jan 2024 18:24:07 GMT", "version": "v2" } ]
2024-01-17
[ [ "Hill", "Richard J.", "" ], [ "Plestid", "Ryan", "" ], [ "Zupan", "Jure", "" ] ]
We investigate the ability of $\mu\rightarrow e$ facilities, Mu2e and COMET, to probe, or discover, new physics with their detector validation datasets. The validation of the detector response may be performed using a dedicated run with $\mu^+$, collecting data below the Michel edge, $E_e\lesssim 52$ MeV; an alternative strategy using $\pi^+\rightarrow e^+ \nu_e$ may also be considered. We focus primarily on a search for a monoenergetic $e^+$ produced via two-body decays $\mu^+ \rightarrow e^+ X$ or $\pi^+\rightarrow e^+X$, with $X$ a light new physics particle. Mu2e can potentially explore new parameter space beyond present astrophysical and laboratory constraints for a set of well motivated models including: axion like particles with flavor violating couplings ($\mu^+ \rightarrow e^+ a$), massive $Z'$ bosons ($\mu^+ \rightarrow Z' e^+$), and heavy neutral leptons ($\pi^+\rightarrow e^+N$). The projected sensitivities presented herein can be achieved in a matter of days.
hep-ph/9601283
Huang Han-wen
Han-Wen Huang, Kuang-Ta Chao
QCD Radiative Correction to the Hadronic Annihilation Rate of $1^{+-}$ Heavy Quarkonium
15 pages latex (6 figures included). In this revised version a update reference and acknowledgement are included
Phys.Rev.D54:3065-3072,1996; Erratum-ibid.D56:7472,1997; Erratum-ibid.D60:079901,1999
10.1103/PhysRevD.54.3065 10.1103/PhysRevD.56.7472 10.1103/PhysRevD.60.079901
null
hep-ph
null
Hadronic annihilation rate of $1^{+-}$ heavy quarkonium is given to next-to-leading order in $\alpha_s$ and leading order in $v^2$ using a recently developed factorization formalism which is based on NRQCD. The result includes both the annihilation of P-wave color-singlet $Q\bar{Q}$ component, and the annihilation of S-wave color-octet $Q\bar{Q}$ component of the quarkonium. The notorious infrared divergences due to soft gluons, i.e., the Logarithms associated with the binding energy, encountered in previous perturbative calculations of $1^{+-}$ quarkonium decays are found to be explicitly cancelled, and a finite result for the decay width to order $\alpha_s^3$ is then obtained.
[ { "created": "Wed, 17 Jan 1996 14:09:01 GMT", "version": "v1" }, { "created": "Tue, 4 Jun 1996 10:52:57 GMT", "version": "v2" }, { "created": "Wed, 13 Aug 1997 16:16:20 GMT", "version": "v3" }, { "created": "Mon, 18 Aug 1997 14:26:29 GMT", "version": "v4" } ]
2014-11-17
[ [ "Huang", "Han-Wen", "" ], [ "Chao", "Kuang-Ta", "" ] ]
Hadronic annihilation rate of $1^{+-}$ heavy quarkonium is given to next-to-leading order in $\alpha_s$ and leading order in $v^2$ using a recently developed factorization formalism which is based on NRQCD. The result includes both the annihilation of P-wave color-singlet $Q\bar{Q}$ component, and the annihilation of S-wave color-octet $Q\bar{Q}$ component of the quarkonium. The notorious infrared divergences due to soft gluons, i.e., the Logarithms associated with the binding energy, encountered in previous perturbative calculations of $1^{+-}$ quarkonium decays are found to be explicitly cancelled, and a finite result for the decay width to order $\alpha_s^3$ is then obtained.
1606.04549
Michael Graesser
Michael L. Graesser
An electroweak basis for neutrinoless double $\beta$ decay
31 pages, 6 tables, 1 figure. v3 updated references and added extended introduction, conclusions unchanged from v2. v4: updated references; final published version
null
10.1007/JHEP08(2017)099
LA-UR-16-23550
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A discovery of neutrinoless double-$\beta$ decay would be profound, providing the first direct experimental evidence of $\Delta L=2$ lepton number violating processes. While a natural explanation is provided by an effective Majorana neutrino mass, other new physics interpretations should be carefully evaluated. At low--energies such new physics could manifest itself in the form of color and $SU(2)_L \times U(1)_{Y}$ invariant higher dimension operators. Here we determine a complete set of electroweak invariant dimension--9 operators, and our analysis supersedes those that only impose $U(1)_{em}$ invariance. Imposing electroweak invariance implies: 1) a significantly reduced set of leading order operators compared to only imposing $U(1)_{em}$ invariance; and 2) other collider signatures. Prior to imposing electroweak invariance we find a minimal basis of 24 dimension-9 operators, which is reduced to 11 electroweak invariant operators at leading order in the expansion in the Higgs vacuum expectation value. We set up a systematic analysis of the hadronic realization of the 4-quark operators using chiral perturbation theory, and apply it to determine which of these operators have long-distance pion enhancements at leading order in the chiral expansion. We also find at dimension--11 and dimension--13 the electroweak invariant operators that after electroweak symmetry breaking produce the remaining $\Delta L=2$ operators that would appear at dimension--9 if only $U(1)_{em}$ is imposed.
[ { "created": "Tue, 14 Jun 2016 20:17:52 GMT", "version": "v1" }, { "created": "Fri, 13 Jan 2017 21:18:49 GMT", "version": "v2" }, { "created": "Sat, 27 May 2017 05:40:56 GMT", "version": "v3" }, { "created": "Tue, 1 Aug 2017 19:24:15 GMT", "version": "v4" } ]
2017-09-13
[ [ "Graesser", "Michael L.", "" ] ]
A discovery of neutrinoless double-$\beta$ decay would be profound, providing the first direct experimental evidence of $\Delta L=2$ lepton number violating processes. While a natural explanation is provided by an effective Majorana neutrino mass, other new physics interpretations should be carefully evaluated. At low--energies such new physics could manifest itself in the form of color and $SU(2)_L \times U(1)_{Y}$ invariant higher dimension operators. Here we determine a complete set of electroweak invariant dimension--9 operators, and our analysis supersedes those that only impose $U(1)_{em}$ invariance. Imposing electroweak invariance implies: 1) a significantly reduced set of leading order operators compared to only imposing $U(1)_{em}$ invariance; and 2) other collider signatures. Prior to imposing electroweak invariance we find a minimal basis of 24 dimension-9 operators, which is reduced to 11 electroweak invariant operators at leading order in the expansion in the Higgs vacuum expectation value. We set up a systematic analysis of the hadronic realization of the 4-quark operators using chiral perturbation theory, and apply it to determine which of these operators have long-distance pion enhancements at leading order in the chiral expansion. We also find at dimension--11 and dimension--13 the electroweak invariant operators that after electroweak symmetry breaking produce the remaining $\Delta L=2$ operators that would appear at dimension--9 if only $U(1)_{em}$ is imposed.
1111.6813
S. Bhattacharyya
Goutam Sau, A. Bhattacharya, S. Bhattacharyya
Rapidity and Pseudorapidity distributions of the Various Hadron-Species Produced in High Energy Nuclear Collisions : A Systematic Approach
21 pages, 13 figures. arXiv admin note: substantial text overlap with arXiv:1011.2095
Journal Of Modern Physics, 2011 2(11) 1354-1365
10.4236/jmp.2011.211168
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the help of a phenomenological approach outlined in the text in some detail, we have dealt here with the description of the plots on rapidity and pseudorapidity spectra of some hadron-secondaries produced in various nucleus-nucleus interactions at high energies. The agreement between the measured data and the attempted fits are, on the whole, modestly satisfactory excepting a very narrow central region in the vicinity of y=$\eta$=0. At last, hints to how the steps suggested in the main body of the text to proceed with the description of the measured data given in the plots could lead finally to a somewhat systematic methodology have also been made.
[ { "created": "Tue, 29 Nov 2011 13:51:35 GMT", "version": "v1" } ]
2011-11-30
[ [ "Sau", "Goutam", "" ], [ "Bhattacharya", "A.", "" ], [ "Bhattacharyya", "S.", "" ] ]
With the help of a phenomenological approach outlined in the text in some detail, we have dealt here with the description of the plots on rapidity and pseudorapidity spectra of some hadron-secondaries produced in various nucleus-nucleus interactions at high energies. The agreement between the measured data and the attempted fits are, on the whole, modestly satisfactory excepting a very narrow central region in the vicinity of y=$\eta$=0. At last, hints to how the steps suggested in the main body of the text to proceed with the description of the measured data given in the plots could lead finally to a somewhat systematic methodology have also been made.
0810.0540
Yara do Amaral Coutinho
E. Ramirez Barreto, Y. A. Coutinho and J. Sa Borges
The Production of Neutral Bilepton Bosons in Proton-Proton Collisions
Poster presented at ICHEP08, Philadelphia, USA, July 2008. 3 pages, LaTeX, 5 eps figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We establish some signatures of the extra bilepton boson ${X^0}$ predicted in the ${SU (3)_C \times SU (3)_L \times U (1)_X}$ model with right-handed neutrinos. We analyze the process $p + p \longrightarrow X^0 +X^{0*} + {\hbox {anything}}$, for center of mass energy regime of the Large Hadron Collider. The main contributions for the neutral bilepton production in $q \bar q$ process come from the $s-$channel ($Z$ and $Z^\prime$ exchanges), when the initial quarks have charge 2/3, and from an additional $t-$channel (heavy quark exchange) when they have -1/3 of the positron electric charge. We calculate some distributions of the final bileptons and from these results we conclude that LHC can show a clear signature for the existence of the $X^0$ predicted in the 3-3-1 model.
[ { "created": "Thu, 2 Oct 2008 21:50:01 GMT", "version": "v1" }, { "created": "Wed, 15 Oct 2008 16:54:23 GMT", "version": "v2" } ]
2008-10-15
[ [ "Barreto", "E. Ramirez", "" ], [ "Coutinho", "Y. A.", "" ], [ "Borges", "J. Sa", "" ] ]
We establish some signatures of the extra bilepton boson ${X^0}$ predicted in the ${SU (3)_C \times SU (3)_L \times U (1)_X}$ model with right-handed neutrinos. We analyze the process $p + p \longrightarrow X^0 +X^{0*} + {\hbox {anything}}$, for center of mass energy regime of the Large Hadron Collider. The main contributions for the neutral bilepton production in $q \bar q$ process come from the $s-$channel ($Z$ and $Z^\prime$ exchanges), when the initial quarks have charge 2/3, and from an additional $t-$channel (heavy quark exchange) when they have -1/3 of the positron electric charge. We calculate some distributions of the final bileptons and from these results we conclude that LHC can show a clear signature for the existence of the $X^0$ predicted in the 3-3-1 model.
1510.08037
Felix Ringer
Patriz Hinderer, Felix Ringer, George F. Sterman and Werner Vogelsang
Toward NNLL Resummation for Hadron Production in Hadronic Collisions
Conference contribution, QCD evolution 2015, Jefferson Lab, Newport News, 26 - 30 May, 2015
null
null
YITP-SB-15-42, LA-UR-15-27999
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results relevant for the extension of threshold resummation beyond the next-to-leading logarithmic (NLL) order for QCD hard-scattering processes. As an example, we consider di-hadron production $H_1 H_2\to h_1 h_2 X$, where the produced pair has a large invariant mass. Taking into account the non-trivial color structure of the partonic hard-scattering process, we determine the hard and soft matrices in color space. In our numerical studies we find a significant improvement compared to previous results at NLL accuracy. In particular, the scale dependence of the resummed cross section is greatly reduced. In addition, we comment on the extension of the techniques developed in this work to other observables relevant for hadronic collisions.
[ { "created": "Tue, 27 Oct 2015 19:41:42 GMT", "version": "v1" } ]
2015-10-28
[ [ "Hinderer", "Patriz", "" ], [ "Ringer", "Felix", "" ], [ "Sterman", "George F.", "" ], [ "Vogelsang", "Werner", "" ] ]
We present results relevant for the extension of threshold resummation beyond the next-to-leading logarithmic (NLL) order for QCD hard-scattering processes. As an example, we consider di-hadron production $H_1 H_2\to h_1 h_2 X$, where the produced pair has a large invariant mass. Taking into account the non-trivial color structure of the partonic hard-scattering process, we determine the hard and soft matrices in color space. In our numerical studies we find a significant improvement compared to previous results at NLL accuracy. In particular, the scale dependence of the resummed cross section is greatly reduced. In addition, we comment on the extension of the techniques developed in this work to other observables relevant for hadronic collisions.
1606.05587
Fabio L. Braghin
Fabio L. Braghin
SU(2) low energy quark effective couplings in weak external magnetic field
12 pages, revised manuscript, Phys. Rev. D 94, 074030 (2016)
Phys. Rev. D 94, 074030 (2016)
10.1103/PhysRevD.94.074030
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work corrections to the usual flavor SU(2) Nambu-Jona-Lasinio coupling due to a weak external magnetic field are calculated by considering quark polarization in a (dressed) gluon exchange mechanism for quark interactions. The quark field is splitted into two components, one that condenses and another one that is a background field for interacting quarks, being the former integrated out. The resulting determinant is expanded for relatively large quark mass and small magnetic field, $(eB_0/{M^*}^2)<1$ by resolving magnetic field dependent low energy quark effective interactions. Besides the corrections for the NJL and vector NJL effective couplings, different $B_0-$dependent effective couplings that break isospin and chiral symmetry emerge.
[ { "created": "Fri, 17 Jun 2016 16:57:10 GMT", "version": "v1" }, { "created": "Sun, 11 Sep 2016 20:16:02 GMT", "version": "v2" }, { "created": "Sun, 23 Oct 2016 20:05:41 GMT", "version": "v3" } ]
2016-10-26
[ [ "Braghin", "Fabio L.", "" ] ]
In this work corrections to the usual flavor SU(2) Nambu-Jona-Lasinio coupling due to a weak external magnetic field are calculated by considering quark polarization in a (dressed) gluon exchange mechanism for quark interactions. The quark field is splitted into two components, one that condenses and another one that is a background field for interacting quarks, being the former integrated out. The resulting determinant is expanded for relatively large quark mass and small magnetic field, $(eB_0/{M^*}^2)<1$ by resolving magnetic field dependent low energy quark effective interactions. Besides the corrections for the NJL and vector NJL effective couplings, different $B_0-$dependent effective couplings that break isospin and chiral symmetry emerge.
hep-ph/0412262
P. Q. Hung
P. Q. Hung
Brane world unification of quark and lepton masses and its implication for the masses of the neutrinos
ReVTeX, 16 double-column pages. Typos corrected. One added reference
Nucl.Phys. B720 (2005) 89-115
10.1016/j.nuclphysb.2005.05.023
null
hep-ph
null
A TeV-scale scenario is constructed in an attempt to understand the relationship between quark and lepton masses. This scenario combines a model of early (TeV) unification of quarks and leptons with the physics of large extra dimensions. It demonstrates a relationship between quark and lepton mass scales at rather ``low'' (TeV) energies which will be dubbed as {\em early quark-lepton mass unification}. It also predicts that the masses of the neutrinos are naturally light and Dirac. There is an interesting correlation between neutrino masses and those of the unconventionally charged fermions which are present in the early unification model. If these unconventional fermions were to lie between 200 GeV and 300 GeV, the Dirac neutrino mass scale is predicted to be between 0.07 eV and 1 eV.
[ { "created": "Fri, 17 Dec 2004 21:07:55 GMT", "version": "v1" }, { "created": "Fri, 21 Jan 2005 17:06:37 GMT", "version": "v2" } ]
2009-11-10
[ [ "Hung", "P. Q.", "" ] ]
A TeV-scale scenario is constructed in an attempt to understand the relationship between quark and lepton masses. This scenario combines a model of early (TeV) unification of quarks and leptons with the physics of large extra dimensions. It demonstrates a relationship between quark and lepton mass scales at rather ``low'' (TeV) energies which will be dubbed as {\em early quark-lepton mass unification}. It also predicts that the masses of the neutrinos are naturally light and Dirac. There is an interesting correlation between neutrino masses and those of the unconventionally charged fermions which are present in the early unification model. If these unconventional fermions were to lie between 200 GeV and 300 GeV, the Dirac neutrino mass scale is predicted to be between 0.07 eV and 1 eV.
hep-ph/9710427
Andrei Belitsky
A.V. Belitsky, B. Geyer, D. Mueller, A. Schaefer
On the leading logarithmic evolution of the off-forward distributions
9 pages, LaTeX, 6 figures; minor corrections: terminology settled, typos in Eq. (3) fixed
Phys.Lett. B421 (1998) 312-318
10.1016/S0370-2693(98)00007-0
null
hep-ph
null
We have found the analytical solution of the LO-evolution equation for off-forward distributions which arise in the processes of deeply virtual Compton scattering or exclusive production of mesons. We present the predictions for their evolution with an input distribution taken from recent bag model calculations.
[ { "created": "Tue, 21 Oct 1997 19:11:27 GMT", "version": "v1" }, { "created": "Thu, 23 Oct 1997 11:28:32 GMT", "version": "v2" }, { "created": "Sun, 26 Oct 1997 10:50:48 GMT", "version": "v3" } ]
2009-10-30
[ [ "Belitsky", "A. V.", "" ], [ "Geyer", "B.", "" ], [ "Mueller", "D.", "" ], [ "Schaefer", "A.", "" ] ]
We have found the analytical solution of the LO-evolution equation for off-forward distributions which arise in the processes of deeply virtual Compton scattering or exclusive production of mesons. We present the predictions for their evolution with an input distribution taken from recent bag model calculations.
hep-ph/0008011
A. Piroth
A. Pir\'oth (Dept. for Theoretical Physics, E\"otv\"os University, Budapest)
Az elektrogyenge f\'azis\'atmenet (The electroweak phase transition)
PhD Thesis in Hungarian, 103 pages, figures
null
null
DT 930/2000
hep-ph
null
The electroweak phase transition provides the most attractive framework to account for the baryon asymmetry of the universe. Comparing results of perturbative and nonperturbative studies is not straightforward, however, due to the different coupling constant definitions. The perturbative one stems from the $\bar{\mathrm{MS}}$ subtraction scheme, while the nonperturbative one uses the static quark potential. The momentum-space perturbative static potential is calculated in the SU(2)--Higgs model, and is Fourier transformed into coordinate space. Based on the connection between the coupling constants, two-loop perturbative and 4-dimensional lattice simulation results are contrasted. The thermodynamical parameters of the phase transition indicate that perturbative results are reliable only for low Higgs masses, far from the endpoint. The value of the endpoint can be refined to $72.1\pm1.4$ GeV. The Higgs mass range for which dimensional reduction yields reliable results is identified. As an extension of the standard model, the MSSM is also studied. Some useful trends are indicated by a simple one-loop perturbative approach: baryogenesis requirements are more easily met if the stop is lighter thanthe top; colour-breaking phase transition may be possible, etc. In order to perform 4D nonperturbative studies the supercomputer PMS was built at E\"otv\"os University. The results and the techniques of the simulations of the bosonic sector of the MSSM performed on PMS are presented. A phase diagram is given, the bubble wall is studied. The cosmologically relevant part of the parameter space is analysed. The results show that baryogenesis is possible within the MSSM if $m_h\leq 103\pm 4$ GeV.
[ { "created": "Tue, 1 Aug 2000 15:20:07 GMT", "version": "v1" }, { "created": "Thu, 3 Aug 2000 11:02:55 GMT", "version": "v2" } ]
2009-09-25
[ [ "Piróth", "A.", "", "Dept. for Theoretical Physics, Eötvös University,\n Budapest" ] ]
The electroweak phase transition provides the most attractive framework to account for the baryon asymmetry of the universe. Comparing results of perturbative and nonperturbative studies is not straightforward, however, due to the different coupling constant definitions. The perturbative one stems from the $\bar{\mathrm{MS}}$ subtraction scheme, while the nonperturbative one uses the static quark potential. The momentum-space perturbative static potential is calculated in the SU(2)--Higgs model, and is Fourier transformed into coordinate space. Based on the connection between the coupling constants, two-loop perturbative and 4-dimensional lattice simulation results are contrasted. The thermodynamical parameters of the phase transition indicate that perturbative results are reliable only for low Higgs masses, far from the endpoint. The value of the endpoint can be refined to $72.1\pm1.4$ GeV. The Higgs mass range for which dimensional reduction yields reliable results is identified. As an extension of the standard model, the MSSM is also studied. Some useful trends are indicated by a simple one-loop perturbative approach: baryogenesis requirements are more easily met if the stop is lighter thanthe top; colour-breaking phase transition may be possible, etc. In order to perform 4D nonperturbative studies the supercomputer PMS was built at E\"otv\"os University. The results and the techniques of the simulations of the bosonic sector of the MSSM performed on PMS are presented. A phase diagram is given, the bubble wall is studied. The cosmologically relevant part of the parameter space is analysed. The results show that baryogenesis is possible within the MSSM if $m_h\leq 103\pm 4$ GeV.
hep-ph/0504100
Jishnu Dey
Manjari Bagchi, Sukanta Daw, Mira Dey and Jishnu Dey
Mean field baryon magnetic moments and sumrules
7 pages, no figure, uses epl.cls
Europhys.Lett.75:548-554,2006
10.1209/epl/i2006-10153-2
null
hep-ph
null
New developments have spurred interest in magnetic moments ($\mu$-s) of baryons. The measurement of some of the decuplet $\mu$-s and the findings of new sumrules from various methods are partly responsible for this renewed interest. Our model, inspired by large colour approximation, is a relativistic self consistent mean field description with a modified Richardson potential and is used to describe the $\mu$-s and masses of all baryons with up (u), down (d) and strange (s) quarks. We have also checked the validity of the Franklin sumrule (referred to as CGSR in the literature) and sumrules of Luty, March-Russell and White. We found that our result for sumrules matches better with experiment than the non-relativistic quark model prediction. We have also seen that quark magnetic moments depend on the baryon in which they belong while the naive quark model expects them to be constant.
[ { "created": "Wed, 13 Apr 2005 17:25:44 GMT", "version": "v1" }, { "created": "Tue, 20 Sep 2005 04:24:16 GMT", "version": "v2" }, { "created": "Wed, 26 Jul 2006 23:34:16 GMT", "version": "v3" } ]
2008-11-26
[ [ "Bagchi", "Manjari", "" ], [ "Daw", "Sukanta", "" ], [ "Dey", "Mira", "" ], [ "Dey", "Jishnu", "" ] ]
New developments have spurred interest in magnetic moments ($\mu$-s) of baryons. The measurement of some of the decuplet $\mu$-s and the findings of new sumrules from various methods are partly responsible for this renewed interest. Our model, inspired by large colour approximation, is a relativistic self consistent mean field description with a modified Richardson potential and is used to describe the $\mu$-s and masses of all baryons with up (u), down (d) and strange (s) quarks. We have also checked the validity of the Franklin sumrule (referred to as CGSR in the literature) and sumrules of Luty, March-Russell and White. We found that our result for sumrules matches better with experiment than the non-relativistic quark model prediction. We have also seen that quark magnetic moments depend on the baryon in which they belong while the naive quark model expects them to be constant.
0707.2314
Mikhail Braun
M.A.Braun
Odderon with a running coupling constant
9 pages, LaTex
Eur.Phys.J.C53:59-63,2008
10.1140/epjc/s10052-007-0428-y
null
hep-ph
null
The running coupling is introduced into the equation for the odderon via the bootstrap relation. It is shown that the previously found odderon state with a maximal intercept, which is constructed from antisymmetric pomeron wave function, continues to exist in the running coupling case. Its intercept is found to remain equal to unity independent of the behaviour assumed for the running coupling at low momenta.
[ { "created": "Mon, 16 Jul 2007 12:54:04 GMT", "version": "v1" } ]
2008-11-26
[ [ "Braun", "M. A.", "" ] ]
The running coupling is introduced into the equation for the odderon via the bootstrap relation. It is shown that the previously found odderon state with a maximal intercept, which is constructed from antisymmetric pomeron wave function, continues to exist in the running coupling case. Its intercept is found to remain equal to unity independent of the behaviour assumed for the running coupling at low momenta.
2304.00336
Wei-Liang Qian
Chong Ye, Wei-Liang Qian, Rui-Hong Yue, Yogiro Hama, Takeshi Kodama
Utilizing maximum likelihood estimator for flow analysis
15 pages, 5 figures, and 8 tables
null
10.1103/PhysRevC.108.024901
INT-PUB-23-017
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the possibility of evaluating flow harmonics by employing the maximum likelihood estimator (MLE). For a given finite multiplicity, the MLE simultaneously furnishes estimations for all the parameters of the underlying distribution function while efficiently suppressing the variance of measures. Also, the method provides a means to assess a specific class of mixed harmonics, which is not straightforwardly feasible by the approaches primarily based on particle correlations. The results are analyzed using the Wald, likelihood ratio, and score tests of hypotheses. Besides, the resultant flow harmonics obtained using MLE are compared with those derived using particle correlations and event plane methods. The dependencies of extracted flow harmonics on the multiplicity of individual events and the total number of events are analyzed. It is shown that the proposed approach works efficiently to deal with the deficiency in detector acceptability. Moreover, we elaborate on a fictitious scenario where the event plane is not a well-defined quantity in the distribution function. For the latter case, the MLE is shown to largely perform better than the two-particle correlation estimator. In this regard, one concludes that the MLE furnishes a meaningful alternative to the existing approaches for flow analysis.
[ { "created": "Sat, 1 Apr 2023 15:26:43 GMT", "version": "v1" }, { "created": "Tue, 6 Jun 2023 00:59:55 GMT", "version": "v2" }, { "created": "Mon, 17 Jul 2023 21:43:00 GMT", "version": "v3" }, { "created": "Sat, 22 Jul 2023 14:57:23 GMT", "version": "v4" } ]
2023-08-16
[ [ "Ye", "Chong", "" ], [ "Qian", "Wei-Liang", "" ], [ "Yue", "Rui-Hong", "" ], [ "Hama", "Yogiro", "" ], [ "Kodama", "Takeshi", "" ] ]
We explore the possibility of evaluating flow harmonics by employing the maximum likelihood estimator (MLE). For a given finite multiplicity, the MLE simultaneously furnishes estimations for all the parameters of the underlying distribution function while efficiently suppressing the variance of measures. Also, the method provides a means to assess a specific class of mixed harmonics, which is not straightforwardly feasible by the approaches primarily based on particle correlations. The results are analyzed using the Wald, likelihood ratio, and score tests of hypotheses. Besides, the resultant flow harmonics obtained using MLE are compared with those derived using particle correlations and event plane methods. The dependencies of extracted flow harmonics on the multiplicity of individual events and the total number of events are analyzed. It is shown that the proposed approach works efficiently to deal with the deficiency in detector acceptability. Moreover, we elaborate on a fictitious scenario where the event plane is not a well-defined quantity in the distribution function. For the latter case, the MLE is shown to largely perform better than the two-particle correlation estimator. In this regard, one concludes that the MLE furnishes a meaningful alternative to the existing approaches for flow analysis.
1812.08314
Dr. Rukmani Mohanta
Atasi Ray, Suchismita Sahoo, Rukmani Mohanta
Probing new physics in semileptonic $\Lambda_b$ decays
33 pages, 18 figures, to appear in PRD
Phys. Rev. D 99, 015015 (2019)
10.1103/PhysRevD.99.015015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent times, several hints of lepton non-universality have been observed in semileptonic $B$ meson decays, both in the charged-current ($b \to c l \bar \nu_l$) and neutral-current ($b \to s ll $) transitions. Motivated by these intriguing results, we perform a model independent analysis of the semileptonic $\Lambda_b$ decays involving the quark level transitions $b \to (u,c) l \nu_l$, in order to scrutinize the nature of new physics. We constrain the new parameter space by using the measured branching ratios of $B_{c, u}^+ \to \tau^+ \nu_\tau$, $B \to \pi \tau \nu_\tau$ processes and the existing experimental results on $R_{D^{(*)}}$, $R_{J/\psi}$ and $R_{\pi}^l$ parameters. Using the constrained parameters, we estimate the branching ratios, forward backward asymmetries, hadron and lepton polarization asymmetries of the $\Lambda_b \to (\Lambda_c, p) l \nu_l$ processes. Moreover, we also examine whether there could be any lepton universality violation in these decay modes.
[ { "created": "Thu, 20 Dec 2018 02:13:03 GMT", "version": "v1" } ]
2019-01-16
[ [ "Ray", "Atasi", "" ], [ "Sahoo", "Suchismita", "" ], [ "Mohanta", "Rukmani", "" ] ]
In recent times, several hints of lepton non-universality have been observed in semileptonic $B$ meson decays, both in the charged-current ($b \to c l \bar \nu_l$) and neutral-current ($b \to s ll $) transitions. Motivated by these intriguing results, we perform a model independent analysis of the semileptonic $\Lambda_b$ decays involving the quark level transitions $b \to (u,c) l \nu_l$, in order to scrutinize the nature of new physics. We constrain the new parameter space by using the measured branching ratios of $B_{c, u}^+ \to \tau^+ \nu_\tau$, $B \to \pi \tau \nu_\tau$ processes and the existing experimental results on $R_{D^{(*)}}$, $R_{J/\psi}$ and $R_{\pi}^l$ parameters. Using the constrained parameters, we estimate the branching ratios, forward backward asymmetries, hadron and lepton polarization asymmetries of the $\Lambda_b \to (\Lambda_c, p) l \nu_l$ processes. Moreover, we also examine whether there could be any lepton universality violation in these decay modes.
hep-ph/9805227
Rajarshi Ray
S. Digal, R. Ray, S. Sengupta, and A. M. Srivastava
Forming a Single, Large, DCC Domain in a Heavy-Ion Collision
RevTex, 22 pages, including 5 figures. Considerably expanded version with results of improved numerical calculations
Int.J.Mod.Phys.A15:2269-2288,2000
10.1142/S0217751X0000094X
null
hep-ph hep-th nucl-th
null
We demonstrate the possibility of forming a single, large domain of disoriented chiral condensate (DCC) in a heavy-ion collision. In our scenario, rapid initial heating of the parton system provides a driving force for the chiral field, moving it away from the true vacuum and forcing it to go to the opposite point on the vacuum manifold. This converts the entire hot region into a single DCC domain. Subsequent rolling down of the chiral field to its true vacuum will then lead to emission of a large number of (approximately) coherent pions. The requirement of suppression of thermal fluctuations to maintain the (approximate) coherence of such a large DCC domain, favors three dimensional expansion of the plasma over the longitudinal expansion even at very early stages of evolution. This also constrains the maximum temperature of the system to lie within a window. We roughly estimate this window to be about 200 - 400 MeV. These results lead us to predict that extremely high energy collisions of {\it very small nuclei} (possibly hadrons) are better suited for observing signatures of a large DCC. Another possibility is to focus on {\it peripheral} collisions of heavy nuclei.
[ { "created": "Tue, 5 May 1998 12:57:54 GMT", "version": "v1" }, { "created": "Fri, 6 Aug 1999 18:36:16 GMT", "version": "v2" } ]
2009-10-31
[ [ "Digal", "S.", "" ], [ "Ray", "R.", "" ], [ "Sengupta", "S.", "" ], [ "Srivastava", "A. M.", "" ] ]
We demonstrate the possibility of forming a single, large domain of disoriented chiral condensate (DCC) in a heavy-ion collision. In our scenario, rapid initial heating of the parton system provides a driving force for the chiral field, moving it away from the true vacuum and forcing it to go to the opposite point on the vacuum manifold. This converts the entire hot region into a single DCC domain. Subsequent rolling down of the chiral field to its true vacuum will then lead to emission of a large number of (approximately) coherent pions. The requirement of suppression of thermal fluctuations to maintain the (approximate) coherence of such a large DCC domain, favors three dimensional expansion of the plasma over the longitudinal expansion even at very early stages of evolution. This also constrains the maximum temperature of the system to lie within a window. We roughly estimate this window to be about 200 - 400 MeV. These results lead us to predict that extremely high energy collisions of {\it very small nuclei} (possibly hadrons) are better suited for observing signatures of a large DCC. Another possibility is to focus on {\it peripheral} collisions of heavy nuclei.
1612.06471
Debtosh Chowdhury
Debtosh Chowdhury, Ketan M. Patel, Xerxes Tata, Sudhir K. Vempati
Indirect Searches of the Degenerate MSSM
27 pages, 8 figures; Comments welcome
Phys. Rev. D 95, 075025 (2017)
10.1103/PhysRevD.95.075025
UH-511-1273-16
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A degenerate sfermionic particle spectrum can escape constraints from flavor physics, and at the same time evade the limits from the direct searches if the degeneracy extends to the gaugino-higgsino sector. Inspired by this, we consider a scenario where all the soft terms have an approximately common mass scale at $M_{\text{SUSY}}$, with splittings $\lesssim \mathcal{O}(10\%)$. As a result, the third generation sfermions have large to maximal (left-right) mixing, the same being the case with charginos and some sectors of the neutralino mass matrix. We study this scenario in the light of discovery of the Higgs boson with mass $\sim$ 125 GeV. We consider constraints from $B$-physics, the anomalous magnetic moment of the muon and the dark matter relic density. We find that a supersymmetric spectrum as light as 600 GeV could be consistent with all current data and also account for the observed anomalous magnetic moment of the muon within $2\sigma$. The neutralino relic density is generally too small to saturate the measured cold dark matter relic density. Direct detection limits from XENON100 and LUX put severe constraints on this scenario which will be conclusively probed by XENONnT experiment.
[ { "created": "Tue, 20 Dec 2016 01:08:41 GMT", "version": "v1" } ]
2017-04-26
[ [ "Chowdhury", "Debtosh", "" ], [ "Patel", "Ketan M.", "" ], [ "Tata", "Xerxes", "" ], [ "Vempati", "Sudhir K.", "" ] ]
A degenerate sfermionic particle spectrum can escape constraints from flavor physics, and at the same time evade the limits from the direct searches if the degeneracy extends to the gaugino-higgsino sector. Inspired by this, we consider a scenario where all the soft terms have an approximately common mass scale at $M_{\text{SUSY}}$, with splittings $\lesssim \mathcal{O}(10\%)$. As a result, the third generation sfermions have large to maximal (left-right) mixing, the same being the case with charginos and some sectors of the neutralino mass matrix. We study this scenario in the light of discovery of the Higgs boson with mass $\sim$ 125 GeV. We consider constraints from $B$-physics, the anomalous magnetic moment of the muon and the dark matter relic density. We find that a supersymmetric spectrum as light as 600 GeV could be consistent with all current data and also account for the observed anomalous magnetic moment of the muon within $2\sigma$. The neutralino relic density is generally too small to saturate the measured cold dark matter relic density. Direct detection limits from XENON100 and LUX put severe constraints on this scenario which will be conclusively probed by XENONnT experiment.
0909.2350
Maxim Chernodub
P.V. Buividovich, M.N. Chernodub, E.V. Luschevskaya, M.I. Polikarpov
Quark electric dipole moment induced by magnetic field
6 pages, 4 figures, RevTex 4.0; revision: comments added, published version
Phys.Rev.D81:036007,2010
10.1103/PhysRevD.81.036007
ITEP-LAT/2009-09
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show numerically that quarks develop an electric dipole moment in the direction of a sufficiently intense magnetic field due to local fluctuations of topological charge. This anomalous CP-odd effect is a spin analogue of the Chiral Magnetic Effect in QCD.
[ { "created": "Sat, 12 Sep 2009 16:30:44 GMT", "version": "v1" }, { "created": "Fri, 12 Feb 2010 16:31:08 GMT", "version": "v2" } ]
2010-04-06
[ [ "Buividovich", "P. V.", "" ], [ "Chernodub", "M. N.", "" ], [ "Luschevskaya", "E. V.", "" ], [ "Polikarpov", "M. I.", "" ] ]
We show numerically that quarks develop an electric dipole moment in the direction of a sufficiently intense magnetic field due to local fluctuations of topological charge. This anomalous CP-odd effect is a spin analogue of the Chiral Magnetic Effect in QCD.
1410.2345
Xin Liu
Xin Liu, Zhen-Jun Xiao, Jing-Wu Li, and Zhi-Tian Zou
Charmless hadronic $B \to (f_1(1285),f_1(1420)) P$ decays in the perturbative QCD approach
revtex file, 25 pages, 6 figures, 4 tables; Matching the published version
Phys. Rev. D 91, 014008 (2015)
10.1103/PhysRevD.91.014008
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study 20 charmless hadronic $B \to f_1 P$ decays in the perturbative QCD(pQCD) formalism with $f_1$ representing axial-vector mesons $f_1(1285)$ and $f_1(1420)$ that result from a mixing of quark-flavor $f_{1q}$ and $f_{1s}$ states with the angle $\phi_{f_1}$. The estimations of branching ratios and CP asymmetries of the considered $B \to f_1 P$ decays are presented in the pQCD approach with $\phi_{f_1} \sim 24^\circ$ from recently measured $B_{d/s} \to J/\psi f_1(1285)$ decays. It is found that (a) the tree(penguin) dominant $B^+ \to f_1 \pi^+(K^+)$ decays with large branching ratios[${\cal O}(10^{-6})$] and large direct CP violations(around 14% $\sim$ 28% in magnitude) simultaneously are believed to be clearly measurable at the LHCb and Belle II experiments; (b) the $B_d \to f_1 K_S^0$ and $B_s \to f_1 (\eta, \eta^{\prime})$ decays with nearly pure penguin contributions and safely negligible tree pollution also have large decay rates in the order of $10^{-6} \sim 10^{-5}$, which can be confronted with the experimental measurements in the near future; (c) as the alternative channels, the $B^+ \to f_1 (\pi^+, K^+)$ and $B_d \to f_1 K_S^0$ decays have the supplementary power in providing more effective constraints on the Cabibbo-Kobayashi-Maskawa weak phases $\alpha$, $\gamma$, and $\beta$ correspondingly, which are explicitly analyzed through the large decay rates and the direct and mixing-induced CP asymmetries in the pQCD approach and are expected to be stringently examined by the measurements with high precision. The complete abstraction can be found in the paper.
[ { "created": "Thu, 9 Oct 2014 03:15:32 GMT", "version": "v1" }, { "created": "Mon, 13 Oct 2014 06:10:47 GMT", "version": "v2" }, { "created": "Wed, 17 Dec 2014 03:06:29 GMT", "version": "v3" }, { "created": "Fri, 26 Dec 2014 02:38:13 GMT", "version": "v4" } ]
2015-01-14
[ [ "Liu", "Xin", "" ], [ "Xiao", "Zhen-Jun", "" ], [ "Li", "Jing-Wu", "" ], [ "Zou", "Zhi-Tian", "" ] ]
We study 20 charmless hadronic $B \to f_1 P$ decays in the perturbative QCD(pQCD) formalism with $f_1$ representing axial-vector mesons $f_1(1285)$ and $f_1(1420)$ that result from a mixing of quark-flavor $f_{1q}$ and $f_{1s}$ states with the angle $\phi_{f_1}$. The estimations of branching ratios and CP asymmetries of the considered $B \to f_1 P$ decays are presented in the pQCD approach with $\phi_{f_1} \sim 24^\circ$ from recently measured $B_{d/s} \to J/\psi f_1(1285)$ decays. It is found that (a) the tree(penguin) dominant $B^+ \to f_1 \pi^+(K^+)$ decays with large branching ratios[${\cal O}(10^{-6})$] and large direct CP violations(around 14% $\sim$ 28% in magnitude) simultaneously are believed to be clearly measurable at the LHCb and Belle II experiments; (b) the $B_d \to f_1 K_S^0$ and $B_s \to f_1 (\eta, \eta^{\prime})$ decays with nearly pure penguin contributions and safely negligible tree pollution also have large decay rates in the order of $10^{-6} \sim 10^{-5}$, which can be confronted with the experimental measurements in the near future; (c) as the alternative channels, the $B^+ \to f_1 (\pi^+, K^+)$ and $B_d \to f_1 K_S^0$ decays have the supplementary power in providing more effective constraints on the Cabibbo-Kobayashi-Maskawa weak phases $\alpha$, $\gamma$, and $\beta$ correspondingly, which are explicitly analyzed through the large decay rates and the direct and mixing-induced CP asymmetries in the pQCD approach and are expected to be stringently examined by the measurements with high precision. The complete abstraction can be found in the paper.
hep-ph/9208220
Ester Ruiz
Maria Herrero and Ester Ruiz-Morales
Study of gamma gamma -> W_L W_L and gamma gamma -> Z_L Z_L reactions with Chiral Lagrangians
14 pages, LaTeX, 4 figures (not included), FTUAM92/22
Phys.Lett. B296 (1992) 397-407
10.1016/0370-2693(92)91339-B
null
hep-ph
null
We analyze the effects of a strongly interacting symmetry breaking sector of the Standard Model in $\gamma \gamma -> W_L^+ W_L^-$ and $\gamma \gamma -> Z_L Z_L$ reactions at TeV energies by using Chiral Lagrangians and Chiral Perturbation Theory. We find significant deviations from the Standard Model predictions for the differential cross sections at high invariant mass of the gauge bosons pair. We study the experimental signals that could be obtained in a high energy and high luminosity dedicated $\gamma\gamma$ collider and estimate the sensitivity that such experiments could reach to the values of the effective lagrangian parameters.
[ { "created": "Tue, 11 Aug 1992 18:35:35 GMT", "version": "v1" } ]
2009-10-22
[ [ "Herrero", "Maria", "" ], [ "Ruiz-Morales", "Ester", "" ] ]
We analyze the effects of a strongly interacting symmetry breaking sector of the Standard Model in $\gamma \gamma -> W_L^+ W_L^-$ and $\gamma \gamma -> Z_L Z_L$ reactions at TeV energies by using Chiral Lagrangians and Chiral Perturbation Theory. We find significant deviations from the Standard Model predictions for the differential cross sections at high invariant mass of the gauge bosons pair. We study the experimental signals that could be obtained in a high energy and high luminosity dedicated $\gamma\gamma$ collider and estimate the sensitivity that such experiments could reach to the values of the effective lagrangian parameters.
hep-ph/9810325
Gabriela Barenboim
Gabriela Barenboim (Institut fur Physik, Johannes Gutenberg Universitat, Mainz)
CP violating lepton asymmetries in Left-Right Models
11 pages, 3 figures included, Latex. To appear in PLB
Phys.Lett. B443 (1998) 317-324
10.1016/S0370-2693(98)01283-0
MZ-TH/98-40
hep-ph
null
Lepton charge asymmetries can be used as an alternative means of searching for new physics. They are interesting because they are small in the Standard Model and therefore, necessarily evidence new physics. In this work we explore the use of lepton asymmetries as a probe of the flavour structure of the left-right symmetric model with spontaneous CP violation. We find that new physics may enhance the magnitude of $a_{SL}$ up to the precent level within the appropiate parameter space.
[ { "created": "Mon, 12 Oct 1998 13:12:25 GMT", "version": "v1" } ]
2009-10-31
[ [ "Barenboim", "Gabriela", "", "Institut fur Physik, Johannes Gutenberg\n Universitat, Mainz" ] ]
Lepton charge asymmetries can be used as an alternative means of searching for new physics. They are interesting because they are small in the Standard Model and therefore, necessarily evidence new physics. In this work we explore the use of lepton asymmetries as a probe of the flavour structure of the left-right symmetric model with spontaneous CP violation. We find that new physics may enhance the magnitude of $a_{SL}$ up to the precent level within the appropiate parameter space.
2104.08921
Mart\'in Novoa-Brunet
Marcel Alguer\'o, Bernat Capdevila, S\'ebastien Descotes-Genon, Joaquim Matias and Mart\'in Novoa-Brunet
$b\to s\ell\ell$ Global Fits after $R_{K_S}$ and $R_{K^{*+}}$
Version accepted for publication in EPJC, extended to include SM predictions for all observables in the fits and additional references
null
10.1140/epjc/s10052-022-10231-1
BARI-TH/21-732
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an up-to-date complete model-independent global fit to $b\to s\ell^+\ell^-$ observables that confirms patterns of New Physics able to explain the data. We include the recent LHCb measurements of $R_K$, $R_{K_S}$, $R_{K^{*+}}$, $B_s \to \phi\mu^+\mu^-$ and $B_s\to\mu\mu$ in our analysis, which now includes 254 observables. This updates our previous analyses and strengthens their two main outcomes. First, the presence of right-handed couplings encoded in the Wilson coefficients $\mathcal{C}_{9'\mu}$ and $\mathcal{C}_{10'\mu}$ remains a viable possibility. Second, a lepton flavour universality violating (LFUV) left-handed lepton coupling ($\mathcal{C}_{9\mu}^{\rm V}=-\mathcal{C}_{10\mu}^{\rm V}$), often preferred from the model building point of view, accommodates the data better if lepton-flavour universal New Physics is allowed, in particular in $\mathcal{C}_{9}^{\rm U}$. We observe that the LFUV observable $Q_5$ offers a very interesting possibility to separate both types of scenarios.
[ { "created": "Sun, 18 Apr 2021 17:44:03 GMT", "version": "v1" }, { "created": "Tue, 14 Dec 2021 16:06:56 GMT", "version": "v2" }, { "created": "Fri, 17 Dec 2021 03:17:36 GMT", "version": "v3" }, { "created": "Wed, 23 Mar 2022 15:05:17 GMT", "version": "v4" } ]
2022-05-04
[ [ "Algueró", "Marcel", "" ], [ "Capdevila", "Bernat", "" ], [ "Descotes-Genon", "Sébastien", "" ], [ "Matias", "Joaquim", "" ], [ "Novoa-Brunet", "Martín", "" ] ]
We present an up-to-date complete model-independent global fit to $b\to s\ell^+\ell^-$ observables that confirms patterns of New Physics able to explain the data. We include the recent LHCb measurements of $R_K$, $R_{K_S}$, $R_{K^{*+}}$, $B_s \to \phi\mu^+\mu^-$ and $B_s\to\mu\mu$ in our analysis, which now includes 254 observables. This updates our previous analyses and strengthens their two main outcomes. First, the presence of right-handed couplings encoded in the Wilson coefficients $\mathcal{C}_{9'\mu}$ and $\mathcal{C}_{10'\mu}$ remains a viable possibility. Second, a lepton flavour universality violating (LFUV) left-handed lepton coupling ($\mathcal{C}_{9\mu}^{\rm V}=-\mathcal{C}_{10\mu}^{\rm V}$), often preferred from the model building point of view, accommodates the data better if lepton-flavour universal New Physics is allowed, in particular in $\mathcal{C}_{9}^{\rm U}$. We observe that the LFUV observable $Q_5$ offers a very interesting possibility to separate both types of scenarios.
1201.4265
Ken Mimasu
K. Mimasu and S. Moretti
ADD and MLS signals in top-antitop final states
Contribution to proceedings of the TOP 2011 international workshop on top quark physics, Sant Feliu de Guixols, Spain, September 2011
null
10.1393/ncc/i2012-11253-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study top-(anti)quark pair production at the Tevatron and Large Hadron Collider (LHC) in the context of the Minimal Length Scenario (MLS) of the Arkani-Hamed, Dimopoulos and Dvali (ADD) model of extra dimensions (XDs). We show that sizable effects onto both the integrated and differential cross section due to graviton mediation are expected for a String scale, M_S, of O(1-10TeV) and several XDs, \delta, all compatible with current experimental constraints. Potential limits on M_S are extracted. We also highlight clear phenomenological differences between a simple ADD scenario and its modification based on using the MLS as a natural regulator for divergent amplitudes of virtual KK graviton exchange.
[ { "created": "Fri, 20 Jan 2012 11:23:23 GMT", "version": "v1" } ]
2022-03-02
[ [ "Mimasu", "K.", "" ], [ "Moretti", "S.", "" ] ]
We study top-(anti)quark pair production at the Tevatron and Large Hadron Collider (LHC) in the context of the Minimal Length Scenario (MLS) of the Arkani-Hamed, Dimopoulos and Dvali (ADD) model of extra dimensions (XDs). We show that sizable effects onto both the integrated and differential cross section due to graviton mediation are expected for a String scale, M_S, of O(1-10TeV) and several XDs, \delta, all compatible with current experimental constraints. Potential limits on M_S are extracted. We also highlight clear phenomenological differences between a simple ADD scenario and its modification based on using the MLS as a natural regulator for divergent amplitudes of virtual KK graviton exchange.
2301.04852
Jin Zhang
Jin Zhang
Note on the evaluation of one type scalar one loop three-point amplitude inspired by $H\rightarrow gg$ decay in the standard model
13 pages, 1 figure, second revised
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the Higgs boson decaying to $gg$ at one loop approximation, the amplitude of scalar one loop three-point diagram with two different internal masses are evaluated and fully analytic results are obtained. The main ingredient of the evaluation is a integral in which the integrand is product of the reciprocal of the integral variable and a logarithm, where the argument of the logarithm is a quadratic function of the general form. The results depend on the choice of the masses of the propagators and the massive external line. In the first case the amplitude contains an infinite series in which each term is a hypergeometric function, in the second case the result is expressed through dilogarithms. In particular, if the three internal lines are taking the same mass, the results will reduce to the known functions in one loop evaluation of Higgs decaying to $gg$ or $\gamma\gamma$.
[ { "created": "Thu, 12 Jan 2023 07:32:11 GMT", "version": "v1" }, { "created": "Tue, 21 Feb 2023 16:02:20 GMT", "version": "v2" }, { "created": "Wed, 22 Feb 2023 11:46:06 GMT", "version": "v3" } ]
2023-02-23
[ [ "Zhang", "Jin", "" ] ]
Motivated by the Higgs boson decaying to $gg$ at one loop approximation, the amplitude of scalar one loop three-point diagram with two different internal masses are evaluated and fully analytic results are obtained. The main ingredient of the evaluation is a integral in which the integrand is product of the reciprocal of the integral variable and a logarithm, where the argument of the logarithm is a quadratic function of the general form. The results depend on the choice of the masses of the propagators and the massive external line. In the first case the amplitude contains an infinite series in which each term is a hypergeometric function, in the second case the result is expressed through dilogarithms. In particular, if the three internal lines are taking the same mass, the results will reduce to the known functions in one loop evaluation of Higgs decaying to $gg$ or $\gamma\gamma$.
0910.0260
David Atwood
David Atwood and Amarjit Soni
Measuring Bs Width Difference at the Upsilon(5s) Using Quantum Entanglement
no figures; Updated version: This is the version accepted by Phys Rev D; Some additional comments were added between equations 8 and 12, also reference 20 to recent D0 results was added
Phys.Rev.D82:036003,2010
10.1103/PhysRevD.82.036003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
About 90% of Bs-bar Bs pairs produced at the Upsilon(5s) resonance are initially Bs*-bar Bs* pairs which decay radiatively to Bs-bar Bs. This implies that the Bs pair will then be in an eigenstate of charge conjugation (i.e. C=-1) and therefore in an entangled state. This allows for a determination of Delta Gamma/Gamma and the CP phase using a number of possible correlations between the decays of the two Bs mesons. In particular, we consider the time integrated correlation; the time ordering asymmetry and the time ordering-charge asymmetry, which in addition to time ordering distinguishes Bs from Bs-bar, for various combinations of final states. With the statistics of about O(10^7-10^8) Upsilon(5s) events available at B factories, we find that the time ordering asymmetry between suitably defined hadronic and flavor specific (tagging) decays offers a promising method for determining the width difference. The corresponding time ordering-charge asymmetry can also bound the mixing phase. Similar observables involving exclusive decays are also considered. At the super B factories with O(50) times greater luminosity time ordering and time ordering-charge asymmetries between inclusive and exclusive modes may also provide additional bounds on the phases in those decays;
[ { "created": "Fri, 2 Oct 2009 14:13:56 GMT", "version": "v1" }, { "created": "Thu, 8 Apr 2010 20:47:30 GMT", "version": "v2" }, { "created": "Tue, 13 Apr 2010 19:12:35 GMT", "version": "v3" }, { "created": "Tue, 20 Jul 2010 21:13:47 GMT", "version": "v4" } ]
2014-11-20
[ [ "Atwood", "David", "" ], [ "Soni", "Amarjit", "" ] ]
About 90% of Bs-bar Bs pairs produced at the Upsilon(5s) resonance are initially Bs*-bar Bs* pairs which decay radiatively to Bs-bar Bs. This implies that the Bs pair will then be in an eigenstate of charge conjugation (i.e. C=-1) and therefore in an entangled state. This allows for a determination of Delta Gamma/Gamma and the CP phase using a number of possible correlations between the decays of the two Bs mesons. In particular, we consider the time integrated correlation; the time ordering asymmetry and the time ordering-charge asymmetry, which in addition to time ordering distinguishes Bs from Bs-bar, for various combinations of final states. With the statistics of about O(10^7-10^8) Upsilon(5s) events available at B factories, we find that the time ordering asymmetry between suitably defined hadronic and flavor specific (tagging) decays offers a promising method for determining the width difference. The corresponding time ordering-charge asymmetry can also bound the mixing phase. Similar observables involving exclusive decays are also considered. At the super B factories with O(50) times greater luminosity time ordering and time ordering-charge asymmetries between inclusive and exclusive modes may also provide additional bounds on the phases in those decays;
hep-ph/0310265
Laurent Lellouch
Laurent Lellouch (CPT, Marseille)
CKM matrix elements from tree-level decays and b-hadron lifetimes
12 pages, 8 figures. Based on Working Group I's summary talk given by L.L. for the group's convenors (Elisabetta Barberio (SMU), Lawrence Gibbons (Cornell), Toru Iijima (Nagoya), L.L.) at the 2nd Workshop on the CKM Unitarity Triangle, IPPP Durham, 5-9 April, 2003
ECONF C0304052:WG119,2003
null
CPT-2003/P.4601
hep-ph
null
We give an updated summary of the topics covered in Working Group I of the 2nd Workshop on the CKM Unitarity Triangle, with emphasis on the results obtained since the 1st CKM Workshop. The topics covered include the measurement of |V_{ub}|, of |V_{cb}| and of non-perturbative Heavy Quark Expansion parameters, and the determination of b-hadron lifetimes and lifetime differences.
[ { "created": "Wed, 22 Oct 2003 12:44:26 GMT", "version": "v1" } ]
2010-11-23
[ [ "Lellouch", "Laurent", "", "CPT, Marseille" ] ]
We give an updated summary of the topics covered in Working Group I of the 2nd Workshop on the CKM Unitarity Triangle, with emphasis on the results obtained since the 1st CKM Workshop. The topics covered include the measurement of |V_{ub}|, of |V_{cb}| and of non-perturbative Heavy Quark Expansion parameters, and the determination of b-hadron lifetimes and lifetime differences.
0709.2844
Yutaka Hosotani
Y. Hosotani, N. Maru, K. Takenaga, Toshifumi Yamashita
Two loop finiteness of Higgs mass and potential in the gauge-Higgs unification
18 pages, 1 figure
Prog.Theor.Phys.118:1053-1068,2007
10.1143/PTP.118.1053
OU-HET 585/2007, KOBE-TH-07-07, TU-797, SISSA 63/2007/EP
hep-ph
null
The zero mode of an extra-dimensional component of gauge potentials serves as a 4D Higgs field in the gauge-Higgs unification. We examine QED on $M^4 \times S^1$ and determine the mass and potential of a 4D Higgs field (the $A_5$ component) at the two loop level with gauge invariant reguralization. It is seen that the mass is free from divergences and independent of the renormalization scheme.
[ { "created": "Tue, 18 Sep 2007 15:06:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Hosotani", "Y.", "" ], [ "Maru", "N.", "" ], [ "Takenaga", "K.", "" ], [ "Yamashita", "Toshifumi", "" ] ]
The zero mode of an extra-dimensional component of gauge potentials serves as a 4D Higgs field in the gauge-Higgs unification. We examine QED on $M^4 \times S^1$ and determine the mass and potential of a 4D Higgs field (the $A_5$ component) at the two loop level with gauge invariant reguralization. It is seen that the mass is free from divergences and independent of the renormalization scheme.
0903.5326
Ian Balitsky
Ian Balitsky and Giovanni A. Chirilli
NLO evolution of color dipoles in N=4 SYM
28 pages, 8 eps figures
Nucl.Phys.B822:45-87,2009
10.1016/j.nuclphysb.2009.07.003
JLAB-THY-09-961
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High-energy behavior of amplitudes in a gauge theory can be reformulated in terms of the evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the conformally invariant BK equation for the evolution of color dipoles. In QCD, the next-to-leading order BK equation has both conformal and non-conformal parts, the latter providing the running of the coupling constant. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal ${\cal N}$=4 SYM theory. We define the "composite dipole operators" with the rapidity cutoff preserving conformal invariance. The resulting M\"obius invariant kernel for these operators agrees with the forward NLO BFKL calculation of Ref. 1.
[ { "created": "Mon, 30 Mar 2009 21:25:40 GMT", "version": "v1" } ]
2009-09-28
[ [ "Balitsky", "Ian", "" ], [ "Chirilli", "Giovanni A.", "" ] ]
High-energy behavior of amplitudes in a gauge theory can be reformulated in terms of the evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the conformally invariant BK equation for the evolution of color dipoles. In QCD, the next-to-leading order BK equation has both conformal and non-conformal parts, the latter providing the running of the coupling constant. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal ${\cal N}$=4 SYM theory. We define the "composite dipole operators" with the rapidity cutoff preserving conformal invariance. The resulting M\"obius invariant kernel for these operators agrees with the forward NLO BFKL calculation of Ref. 1.
hep-ph/0504158
Mu-Chun Chen
Mu-Chun Chen
Generation of Small Neutrino Majorana Masses in a Randall-Sundrum Model
16 pages, 1 figure, RevTeX; v2: version to appear in Phys. Rev. D
Phys.Rev. D71 (2005) 113010
10.1103/PhysRevD.71.113010
BNL-HET-05/14
hep-ph
null
We propose a model, in the framework of 5D with warped geometry, in which small neutrino Majorana masses are generated by tree level coupling of lepton doublets to a SU(2)_{L}-triplet scalar field, which is coupled to a bulk SM-singlet. The neutrino mass scale is determined by the bulk mass term (alpha_{S}) of the singlet as ve^{-2(alpha_{S}-1)*pi*kR}. This suppression is due to a small overlap between the profile of the singlet zero mode and the triplet, which is confined to the TeV brane. The generic form for the neutrino mass matrix due to the overlap between the fermions is not compatible with the LMA solution. This is overcome by imposing a Z_{4} symmetry, which is softly broken by couplings of the triplet Higgs to the lepton doublets. This model successfully reproduces the observed masses and mixing angles in charged lepton sector as well as in the neutrino sector, in addition to having a prediction of |U_{e3}| ~ O(0.01). The mass of the triplet is of the order of a TeV, and could be produced at upcoming collider experiments. The doubly charged member of the triplet can decay into two same sign charged leptons yielding the whole triplet coupling matrix which, in turn, gives the mixing matrix in the neutrino sector.
[ { "created": "Mon, 18 Apr 2005 19:00:19 GMT", "version": "v1" }, { "created": "Tue, 7 Jun 2005 20:58:22 GMT", "version": "v2" } ]
2009-11-11
[ [ "Chen", "Mu-Chun", "" ] ]
We propose a model, in the framework of 5D with warped geometry, in which small neutrino Majorana masses are generated by tree level coupling of lepton doublets to a SU(2)_{L}-triplet scalar field, which is coupled to a bulk SM-singlet. The neutrino mass scale is determined by the bulk mass term (alpha_{S}) of the singlet as ve^{-2(alpha_{S}-1)*pi*kR}. This suppression is due to a small overlap between the profile of the singlet zero mode and the triplet, which is confined to the TeV brane. The generic form for the neutrino mass matrix due to the overlap between the fermions is not compatible with the LMA solution. This is overcome by imposing a Z_{4} symmetry, which is softly broken by couplings of the triplet Higgs to the lepton doublets. This model successfully reproduces the observed masses and mixing angles in charged lepton sector as well as in the neutrino sector, in addition to having a prediction of |U_{e3}| ~ O(0.01). The mass of the triplet is of the order of a TeV, and could be produced at upcoming collider experiments. The doubly charged member of the triplet can decay into two same sign charged leptons yielding the whole triplet coupling matrix which, in turn, gives the mixing matrix in the neutrino sector.
2305.02851
Francesco Costa
Francesco Costa
Two-component WIMP $-$ FIMP dark matter
arXiv admin note: substantial text overlap with arXiv:2209.13653
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The document discusses a proposed extension to the Standard Model that aims to explain the presence of neutrino masses and the existence of dark matter. The model includes two potential candidates for dark matter, a vector WIMP and a fermion FIMP, and their combined presence accounts for the total amount of observed dark matter. This study examines the various ways in which dark matter could be produced within this model and explores the connections between the dark matter and neutrino sectors. It also examines various constraints from existing and future experiments. Additionally, the model includes a scalar field that can play a role in a first-order phase transition in the early universe, and the article looks at the potential for the production of gravitational waves as a result of this phase transition and their detectability. This study also assesses the possibility for this phase transition to be strong enough to drive the electroweak baryogenesis.
[ { "created": "Thu, 4 May 2023 14:11:45 GMT", "version": "v1" }, { "created": "Thu, 21 Sep 2023 17:47:45 GMT", "version": "v2" } ]
2023-09-22
[ [ "Costa", "Francesco", "" ] ]
The document discusses a proposed extension to the Standard Model that aims to explain the presence of neutrino masses and the existence of dark matter. The model includes two potential candidates for dark matter, a vector WIMP and a fermion FIMP, and their combined presence accounts for the total amount of observed dark matter. This study examines the various ways in which dark matter could be produced within this model and explores the connections between the dark matter and neutrino sectors. It also examines various constraints from existing and future experiments. Additionally, the model includes a scalar field that can play a role in a first-order phase transition in the early universe, and the article looks at the potential for the production of gravitational waves as a result of this phase transition and their detectability. This study also assesses the possibility for this phase transition to be strong enough to drive the electroweak baryogenesis.
hep-ph/9910267
Kneur Jean-Loic
J.-L. Kneur and G. Moultaka (Montpellier U.)
A Direct Reconstruction of the Gaugino Parameters with Phases
5 pages, using sprocl.sty (included), 4 PS figures. Contribution to the proceedings of the International Workshop on Linear Colliders, Sitges, Spain, April 28-May 5, 1999
null
null
PM/99-36
hep-ph
null
A simple algebraic algorithm is described to recover the (complex valued) gaugino/Higgsino basic parameters $\mu = |\mu| e^{i \phi_\mu}$, $M_1 = |M_1| e^{i \phi_{M_1}}$, $M_2 = |M_2|$, directly in terms of (a minimal set of) neutralino and chargino masses, accurately measurable at future linear collider energies. An ambiguity in the $M_1$ reconstruction can be resolved by measuring the corresponding $e^+e^- \to \chi^0_1 \chi^0_2$ cross section. This approach should simplify the determination of allowed ranges of the gaugino parameters, in particular if only a partial set of gaugino masses were measured.
[ { "created": "Thu, 7 Oct 1999 14:50:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kneur", "J. -L.", "", "Montpellier U." ], [ "Moultaka", "G.", "", "Montpellier U." ] ]
A simple algebraic algorithm is described to recover the (complex valued) gaugino/Higgsino basic parameters $\mu = |\mu| e^{i \phi_\mu}$, $M_1 = |M_1| e^{i \phi_{M_1}}$, $M_2 = |M_2|$, directly in terms of (a minimal set of) neutralino and chargino masses, accurately measurable at future linear collider energies. An ambiguity in the $M_1$ reconstruction can be resolved by measuring the corresponding $e^+e^- \to \chi^0_1 \chi^0_2$ cross section. This approach should simplify the determination of allowed ranges of the gaugino parameters, in particular if only a partial set of gaugino masses were measured.
1106.5592
Kentarou Mawatari
K. Mawatari, B. Oexl, Y. Takaesu
Associated production of light gravitinos in e^+e^- and e^-\gamma collisions
12 pages, 12 figures, 4 tables; references added, version to appear in EPJC
null
10.1140/epjc/s10052-011-1783-2
KEK-TH-1462
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Light gravitino productions in association with a neutralino (selectron) in e^+e^- (e^-\gamma) collisions are restudied in a scenario that the lightest supersymmetric particle is a gravitino and the produced neutralino (selectron) promptly decays into a photon (electron) and a gravitino. We explicitly give the helicity amplitudes for the production processes by using the effective goldstino interaction Lagrangian, and present the cross sections with different collision energies and mass spectra. We also examine selection efficiencies by kinematical cuts and beam polarizations for the signal and background processes, and show that the energy and angular distributions of the photon (electron) can explore the mass of the t-channel exchange particle as well as the mass of the decaying particle at a future e^+e^- (e^-\gamma) collider.
[ { "created": "Tue, 28 Jun 2011 08:39:00 GMT", "version": "v1" }, { "created": "Sun, 13 Nov 2011 15:24:33 GMT", "version": "v2" } ]
2015-05-28
[ [ "Mawatari", "K.", "" ], [ "Oexl", "B.", "" ], [ "Takaesu", "Y.", "" ] ]
Light gravitino productions in association with a neutralino (selectron) in e^+e^- (e^-\gamma) collisions are restudied in a scenario that the lightest supersymmetric particle is a gravitino and the produced neutralino (selectron) promptly decays into a photon (electron) and a gravitino. We explicitly give the helicity amplitudes for the production processes by using the effective goldstino interaction Lagrangian, and present the cross sections with different collision energies and mass spectra. We also examine selection efficiencies by kinematical cuts and beam polarizations for the signal and background processes, and show that the energy and angular distributions of the photon (electron) can explore the mass of the t-channel exchange particle as well as the mass of the decaying particle at a future e^+e^- (e^-\gamma) collider.
0903.2364
Mu Chengfu
Chengfu Mu, Pengfei Zhuang
Pion Superfluidity beyond Mean Field Approximation In Nambu--Jona-Lasinio Model
7 pages, 4 figures
Phys.Rev.D79:094006,2009
10.1103/PhysRevD.79.094006
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate pion superfluidity in the frame of two flavor Nambu--Jona-Lasinio model beyond mean field approximation. We calculate the thermodynamics to the next to leading order in an expansion in the inverse number of colors, including both quark and meson contributions at finite temperature and baryon and isospin density. Due to the meson fluctuations, the Sarma phase which exists at mean field level is washed away, and the Bose-Einstein condensation region at low isospin density is highly suppressed.
[ { "created": "Fri, 13 Mar 2009 12:00:21 GMT", "version": "v1" }, { "created": "Fri, 8 May 2009 02:54:01 GMT", "version": "v2" } ]
2009-10-29
[ [ "Mu", "Chengfu", "" ], [ "Zhuang", "Pengfei", "" ] ]
We investigate pion superfluidity in the frame of two flavor Nambu--Jona-Lasinio model beyond mean field approximation. We calculate the thermodynamics to the next to leading order in an expansion in the inverse number of colors, including both quark and meson contributions at finite temperature and baryon and isospin density. Due to the meson fluctuations, the Sarma phase which exists at mean field level is washed away, and the Bose-Einstein condensation region at low isospin density is highly suppressed.
hep-ph/0511283
Ales Psaker
Ales Psaker
Inclusive and Exclusive Compton Processes in Quantum Chromodynamics
Ph.D. Thesis (Advisor: A. Radyushkin), Old Dominion University, Dec 2005
null
null
null
hep-ph
null
In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized parton distributions (GPDs) may be observed in hard exclusive reactions such as deeply virtual Compton scattering. We develop an extension of this particular process into the weak interaction sector. We also investigate a possible application of the GPD formalism to wide-angle real Compton scattering.
[ { "created": "Wed, 23 Nov 2005 23:45:59 GMT", "version": "v1" }, { "created": "Sat, 28 Jan 2006 22:42:18 GMT", "version": "v2" } ]
2007-05-23
[ [ "Psaker", "Ales", "" ] ]
In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized parton distributions (GPDs) may be observed in hard exclusive reactions such as deeply virtual Compton scattering. We develop an extension of this particular process into the weak interaction sector. We also investigate a possible application of the GPD formalism to wide-angle real Compton scattering.
hep-ph/9301289
null
J. G. Koerner, A. Pilaftsis, K. Schilcher
Leptonic CP Asymmetries in Flavor-changing H0 Decays
22 pages(1 Fig. not included), LaTeX, MZ-TH/92-30
Phys.Rev.D47:1080-1086,1993
10.1103/PhysRevD.47.1080
null
hep-ph
null
Leptonic flavor-changing $H^0$ decays with branching ratios of the order of $10^{-5}-10^{-6}$ may constitute an interesting framework when looking for large $CP$-violating effects. We show that leptonic $CP$~asymmetries of an intermediate $H^0$ boson can be fairly large in natural scenarios of the minimal Standard Model ($SM$) with right-handed neutrinos, at a level that may be probed at future $H^0$~factories.
[ { "created": "Thu, 28 Jan 1993 12:11:00 GMT", "version": "v1" } ]
2010-11-01
[ [ "Koerner", "J. G.", "" ], [ "Pilaftsis", "A.", "" ], [ "Schilcher", "K.", "" ] ]
Leptonic flavor-changing $H^0$ decays with branching ratios of the order of $10^{-5}-10^{-6}$ may constitute an interesting framework when looking for large $CP$-violating effects. We show that leptonic $CP$~asymmetries of an intermediate $H^0$ boson can be fairly large in natural scenarios of the minimal Standard Model ($SM$) with right-handed neutrinos, at a level that may be probed at future $H^0$~factories.
hep-ph/0108078
Rainer Jakob
Nicola Bianchi (INFN Frascati) and Rainer Jakob (U.Wuppertal)
Summary Report of the Spin Physics Working Group
20 pages, 14 Postscript figures, summary talk presented at the 9th International Workshop on Deep Inelastic Scattering (DIS 2001), Bologna, April 2001
null
10.1142/9789812778345_0011
null
hep-ph hep-ex
null
The contributions to the Spin Physics WG are summarized. Several new experimental results and plans for new measurements have been reported. An improved theoretical understanding of the most recent hot topics in spin physics has been discussed by many authors especially in the new fields of the transversity and generalized parton distributions.
[ { "created": "Wed, 8 Aug 2001 15:49:53 GMT", "version": "v1" } ]
2015-06-25
[ [ "Bianchi", "Nicola", "", "INFN Frascati" ], [ "Jakob", "Rainer", "", "U.Wuppertal" ] ]
The contributions to the Spin Physics WG are summarized. Several new experimental results and plans for new measurements have been reported. An improved theoretical understanding of the most recent hot topics in spin physics has been discussed by many authors especially in the new fields of the transversity and generalized parton distributions.
1304.5724
Fei Wang
Chengcheng Han, Fei Wang, Jin Min Yang
Natural SUSY from SU(5) Orbifold GUT
JHEP style, 21 pages, 3 figures. Minor changes, references added
JHEP11(2013)197
10.1007/JHEP11(2013)197
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a realistic 5D orbifold GUT model that can reduce to natural (or radiative natural) supersymmetry as the low energy effective theory. Supersymmetry as well as gauge symmetry are broken by the twist boundary conditions. We find that it is non-trivial to introduce other flavor symmetry other than the $SU(2)_R$ R-symmetry. We ameliorate the tension between the small number of free parameters and the successful electroweak symmetry breaking by introducing non-minimal Kahler potentials. A large trilinear term $A_t$, which is necessary to give a 125 GeV Higgs boson, is naturally provided in our scenario. A scan under current experimental constraints shows that our model can realize natural (or radiative natural) supersymmetry. Only radiative natural supersymmetry can naturally lead to 125 GeV higgs. Additional dark matter species other than neutralino(like axion) are needed to provide enough relic density. Relatively large stop masses are necessary to give realistic higg mass in most of the parameter spaces.
[ { "created": "Sun, 21 Apr 2013 12:04:27 GMT", "version": "v1" }, { "created": "Tue, 23 Apr 2013 05:19:59 GMT", "version": "v2" }, { "created": "Thu, 28 Nov 2013 05:38:31 GMT", "version": "v3" } ]
2015-06-15
[ [ "Han", "Chengcheng", "" ], [ "Wang", "Fei", "" ], [ "Yang", "Jin Min", "" ] ]
We propose a realistic 5D orbifold GUT model that can reduce to natural (or radiative natural) supersymmetry as the low energy effective theory. Supersymmetry as well as gauge symmetry are broken by the twist boundary conditions. We find that it is non-trivial to introduce other flavor symmetry other than the $SU(2)_R$ R-symmetry. We ameliorate the tension between the small number of free parameters and the successful electroweak symmetry breaking by introducing non-minimal Kahler potentials. A large trilinear term $A_t$, which is necessary to give a 125 GeV Higgs boson, is naturally provided in our scenario. A scan under current experimental constraints shows that our model can realize natural (or radiative natural) supersymmetry. Only radiative natural supersymmetry can naturally lead to 125 GeV higgs. Additional dark matter species other than neutralino(like axion) are needed to provide enough relic density. Relatively large stop masses are necessary to give realistic higg mass in most of the parameter spaces.
2307.12820
Mai Qiao
Mai Qiao, Chen Xia and Yu-Feng Zhou
Diurnal modulation of electron recoils from DM-nucleon scattering through the Migdal effect
Comments on the Migdal effects added, figures and text improved, version accepted by JCAP
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Halo dark matter (DM) particles could lose energy due to the scattering off nuclei within the Earth before reaching the underground detectors of DM direct detection experiments. This Earth shielding effect can result in diurnal modulation of the DM-induced recoil event rates observed underground due to the self-rotation of the Earth. For electron recoil signals from DM-electron scatterings, the current experimental constraints are very stringent such that the diurnal modulation cannot be observed for halo DM. We propose a novel type of diurnal modulation effect: diurnal modulation in electron recoil signals induced by DM-nucleon scattering via the Migdal effect. We set so far the most stringent constraints on DM-nucleon scattering cross section via the Migdal effect for sub-GeV DM using the S2-only data of PandaX-II and PandaX-4T with improved simulations of the Earth shielding effect. Based on the updated constraints, we show that the Migdal effect induced diurnal modulation of electron events can still be significant in the low energy region, and can be probed by experiments such as PandaX-4T in the near future.
[ { "created": "Mon, 24 Jul 2023 14:14:57 GMT", "version": "v1" }, { "created": "Tue, 22 Aug 2023 15:16:45 GMT", "version": "v2" }, { "created": "Wed, 1 Nov 2023 06:44:15 GMT", "version": "v3" } ]
2023-11-02
[ [ "Qiao", "Mai", "" ], [ "Xia", "Chen", "" ], [ "Zhou", "Yu-Feng", "" ] ]
Halo dark matter (DM) particles could lose energy due to the scattering off nuclei within the Earth before reaching the underground detectors of DM direct detection experiments. This Earth shielding effect can result in diurnal modulation of the DM-induced recoil event rates observed underground due to the self-rotation of the Earth. For electron recoil signals from DM-electron scatterings, the current experimental constraints are very stringent such that the diurnal modulation cannot be observed for halo DM. We propose a novel type of diurnal modulation effect: diurnal modulation in electron recoil signals induced by DM-nucleon scattering via the Migdal effect. We set so far the most stringent constraints on DM-nucleon scattering cross section via the Migdal effect for sub-GeV DM using the S2-only data of PandaX-II and PandaX-4T with improved simulations of the Earth shielding effect. Based on the updated constraints, we show that the Migdal effect induced diurnal modulation of electron events can still be significant in the low energy region, and can be probed by experiments such as PandaX-4T in the near future.
hep-ph/0401035
Frank Wilczek
Frank Wilczek
From Concept to Reality to Vision
7 pages; Speech in acceptance of EPS prize for high energy physics, Aachen, August 2003
Eur.Phys.J.C33:s1-s4,2004
10.1140/epjcd/s2004-03-1694-8
null
hep-ph hep-th
null
I take a brief look at three frontiers of high-energy physics, illustrating how important parts of our current thinking evolved from earlier explorations at preceding frontiers.
[ { "created": "Wed, 7 Jan 2004 19:53:06 GMT", "version": "v1" } ]
2014-11-17
[ [ "Wilczek", "Frank", "" ] ]
I take a brief look at three frontiers of high-energy physics, illustrating how important parts of our current thinking evolved from earlier explorations at preceding frontiers.
1612.07933
Simone Biondini
Simone Biondini
Effective field theories for heavy Majorana neutrinos in a thermal bath
PhD thesis, 220 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy Majorana neutrinos enter in many scenarios of physics beyond the Standard Model and play a special role in the leptogenesis framework as origin of the baryon asymmetry in the universe. In this thesis, we develop an effective field theory for non-relativistic Majorana particles. We apply the effective field theory so obtained to address calculations in a hot medium which models the early stages of the universe evolution. In particular, we apply it to the case of a heavy Majorana neutrino decaying in a hot plasma of Standard Model particles, whose temperature is much smaller than the mass of the Majorana neutrino but still much larger than the electroweak scale, and the derivation of the neutrino thermal width is revisited in an EFT fashion. Assuming the same hierarchy between heavy neutrino masses and the temperature, we compute systematically thermal corrections to the direct and indirect CP asymmetries in the Majorana neutrino decays. These are key ingredients entering the equations that describe the thermodynamic evolution of the induced lepton-number asymmetry eventually leading to the baryon asymmetry in the universe. We consider the case of two Majorana neutrinos with nearly degenerate masses, that allows for a resonant enhancement of the CP asymmetry, and a hierarchical spectrum with one heavy neutrino much lighter than the other neutrino species. Flavour effects are also taken into account in the derivation of the CP asymmetries at finite temperature.
[ { "created": "Fri, 23 Dec 2016 10:58:17 GMT", "version": "v1" } ]
2016-12-26
[ [ "Biondini", "Simone", "" ] ]
Heavy Majorana neutrinos enter in many scenarios of physics beyond the Standard Model and play a special role in the leptogenesis framework as origin of the baryon asymmetry in the universe. In this thesis, we develop an effective field theory for non-relativistic Majorana particles. We apply the effective field theory so obtained to address calculations in a hot medium which models the early stages of the universe evolution. In particular, we apply it to the case of a heavy Majorana neutrino decaying in a hot plasma of Standard Model particles, whose temperature is much smaller than the mass of the Majorana neutrino but still much larger than the electroweak scale, and the derivation of the neutrino thermal width is revisited in an EFT fashion. Assuming the same hierarchy between heavy neutrino masses and the temperature, we compute systematically thermal corrections to the direct and indirect CP asymmetries in the Majorana neutrino decays. These are key ingredients entering the equations that describe the thermodynamic evolution of the induced lepton-number asymmetry eventually leading to the baryon asymmetry in the universe. We consider the case of two Majorana neutrinos with nearly degenerate masses, that allows for a resonant enhancement of the CP asymmetry, and a hierarchical spectrum with one heavy neutrino much lighter than the other neutrino species. Flavour effects are also taken into account in the derivation of the CP asymmetries at finite temperature.
hep-ph/0306235
F. Arleo
Francois Arleo
Quenching of hadron spectra in DIS on nuclear targets
20 pages, 8 figures
Eur.Phys.J.C30:213-221,2003
10.1140/epjc/s2003-01289-x
ECT*-03-13
hep-ph
null
The multiple scatterings incurred by a hard quark produced in a nuclear medium induce the emission of soft gluons which carry a fraction of the quark energy and eventually affect the hadronization process. Here, the depletion of semi-inclusive hadron spectra in DIS on various nuclei (N, Ne, Cu, Kr) is computed as a function of nu and z to leading order in alpha_s through medium-modified fragmentation functions. Using the transport coefficient q previously determined from Drell-Yan production, the predictions are found to be in good agreement with EMC and HERMES preliminary data. Calculations on Xe targets are also presented and discussed.
[ { "created": "Tue, 24 Jun 2003 12:04:41 GMT", "version": "v1" }, { "created": "Wed, 2 Jul 2003 15:10:24 GMT", "version": "v2" } ]
2011-09-13
[ [ "Arleo", "Francois", "" ] ]
The multiple scatterings incurred by a hard quark produced in a nuclear medium induce the emission of soft gluons which carry a fraction of the quark energy and eventually affect the hadronization process. Here, the depletion of semi-inclusive hadron spectra in DIS on various nuclei (N, Ne, Cu, Kr) is computed as a function of nu and z to leading order in alpha_s through medium-modified fragmentation functions. Using the transport coefficient q previously determined from Drell-Yan production, the predictions are found to be in good agreement with EMC and HERMES preliminary data. Calculations on Xe targets are also presented and discussed.
1109.3105
Yutaka Tobita
Kenzo Ishikawa and Yutaka Tobita
Resolving LSND anomaly by neutrino diffraction
14pages, 5figures, Sec.1 and Sec.4 were revised partly. Eq.6 was added
null
null
EPHOU-11-007
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the charged pion decay, a neutrino is produced in pair with a charged lepton and they have the same production rate. In this paper we show that neutrinos have their own space-time correlations in a wide area and are detected in a different manner from charged leptons, owing to extremely small mass. The neutrino flux reveals a unique interference effect in the form of diffraction of non-stationary waves. The diffraction component of the flux shows a slow position-dependence and leads to an electron neutrino at short base-line regions. The electron neutrino flux at short distances is attributed to the neutrino diffraction and the one at long distances is to the normal flavor oscillation. The former depends upon the average mass-squared $\bar m^2_\nu$ and the latter depends upon the mass-squared difference $\delta m^2_\nu$. The LSND and the two neutrino experiment (TWN) measure $\bar m^2_\nu$ and the other experiments measure $\delta m^2_\nu$. Hence they are consistent with each other. The neutrino diffraction would supply valuable information on the absolute neutrino mass.
[ { "created": "Wed, 14 Sep 2011 15:07:28 GMT", "version": "v1" }, { "created": "Wed, 28 Dec 2011 08:54:24 GMT", "version": "v2" }, { "created": "Sun, 1 Apr 2012 03:04:15 GMT", "version": "v3" }, { "created": "Mon, 23 Apr 2012 11:36:36 GMT", "version": "v4" } ]
2012-04-25
[ [ "Ishikawa", "Kenzo", "" ], [ "Tobita", "Yutaka", "" ] ]
In the charged pion decay, a neutrino is produced in pair with a charged lepton and they have the same production rate. In this paper we show that neutrinos have their own space-time correlations in a wide area and are detected in a different manner from charged leptons, owing to extremely small mass. The neutrino flux reveals a unique interference effect in the form of diffraction of non-stationary waves. The diffraction component of the flux shows a slow position-dependence and leads to an electron neutrino at short base-line regions. The electron neutrino flux at short distances is attributed to the neutrino diffraction and the one at long distances is to the normal flavor oscillation. The former depends upon the average mass-squared $\bar m^2_\nu$ and the latter depends upon the mass-squared difference $\delta m^2_\nu$. The LSND and the two neutrino experiment (TWN) measure $\bar m^2_\nu$ and the other experiments measure $\delta m^2_\nu$. Hence they are consistent with each other. The neutrino diffraction would supply valuable information on the absolute neutrino mass.
1302.6048
Helios Sanchis-Alepuz
Helios Sanchis-Alepuz, Richard Williams and Reinhard Alkofer
Delta and Omega electromagnetic form factors in a three-body covariant Bethe-Salpeter approach
12 pages, 6 figures. Submitted to Phys.Rev.D
null
10.1103/PhysRevD.87.096015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The electromagnetic form factors of the Delta and Omega baryons are calculated in the framework of Poincare-covariant bound-state equations. The quark-quark interaction is truncated to a single dressed-gluon exchange where for the dressings we use two different models and compare the results. The calculation predicts an oblate shape for the electric charge distribution and a prolate shape for the magnetic dipole distribution. We also identify the necessity of including pion-cloud corrections at low photon-momentum transfer.
[ { "created": "Mon, 25 Feb 2013 11:05:35 GMT", "version": "v1" }, { "created": "Wed, 27 Feb 2013 10:32:45 GMT", "version": "v2" } ]
2013-06-05
[ [ "Sanchis-Alepuz", "Helios", "" ], [ "Williams", "Richard", "" ], [ "Alkofer", "Reinhard", "" ] ]
The electromagnetic form factors of the Delta and Omega baryons are calculated in the framework of Poincare-covariant bound-state equations. The quark-quark interaction is truncated to a single dressed-gluon exchange where for the dressings we use two different models and compare the results. The calculation predicts an oblate shape for the electric charge distribution and a prolate shape for the magnetic dipole distribution. We also identify the necessity of including pion-cloud corrections at low photon-momentum transfer.
1904.08458
Philip Ilten
Xabier Cid Vidal, Philip Ilten, Jonathan Plews, Brian Shuve, and Yotam Soreq
Discovering True Muonium at LHCb
12 pages, 5 figures; v2: edits from comments and review, matched to PRD version
Phys. Rev. D 100, 053003 (2019)
10.1103/PhysRevD.100.053003
CERN-TH-2019-049
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the potential of the LHCb experiment to discover, for the first time, the $\mu^+\mu^-$ true muonium bound state. We propose a search for the vector $1^3S_1$ state, $\mathcal{T\!M}$, which kinetically mixes with the photon and dominantly decays to $e^+e^-$. We demonstrate that a search for $\eta \to \gamma \mathcal{T\!M}$, $\mathcal{T\!M}\to e^+e^-$ in a displaced vertex can exceed a significance of 5 standard deviations assuming statistical uncertainties. We present two possible searches: an inclusive search for the $e^+e^-$ vertex, and an exclusive search which requires an additional photon and a reconstruction of the $\eta$ mass.
[ { "created": "Wed, 17 Apr 2019 19:08:19 GMT", "version": "v1" }, { "created": "Fri, 13 Sep 2019 08:07:08 GMT", "version": "v2" } ]
2019-09-18
[ [ "Vidal", "Xabier Cid", "" ], [ "Ilten", "Philip", "" ], [ "Plews", "Jonathan", "" ], [ "Shuve", "Brian", "" ], [ "Soreq", "Yotam", "" ] ]
We study the potential of the LHCb experiment to discover, for the first time, the $\mu^+\mu^-$ true muonium bound state. We propose a search for the vector $1^3S_1$ state, $\mathcal{T\!M}$, which kinetically mixes with the photon and dominantly decays to $e^+e^-$. We demonstrate that a search for $\eta \to \gamma \mathcal{T\!M}$, $\mathcal{T\!M}\to e^+e^-$ in a displaced vertex can exceed a significance of 5 standard deviations assuming statistical uncertainties. We present two possible searches: an inclusive search for the $e^+e^-$ vertex, and an exclusive search which requires an additional photon and a reconstruction of the $\eta$ mass.
2406.15566
Yago Porto
Chee Sheng Fong and Yago Porto
Constraining pseudo-Diracness with astrophysical neutrino flavors
13 pages + references, 4 figures
null
null
null
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
The three Standard Model neutrinos can have Majorana mass or strictly Dirac mass, but both scenarios are practically indistinguishable in neutrino oscillation experiments. If they are pseudo-Dirac, however, there will be new mass splittings among the pseudo-Dirac pairs, potentially leaving traces in neutrino oscillation phenomena. In this work, we use flavor ratios of astrophysical neutrinos to discriminate different possible mass spectra of pseudo-Dirac neutrinos. We show that it will be possible to impose robust bounds of order $\delta m^2_3 \lesssim 10^{-12}$ $\text{eV}^2$ on the new mass squared splitting involving the third pseudo-Dirac mass eigenstates (those with the least electron flavor composition) with the future experiment IceCube-Gen2. The derived sensitivity is robust because it only assumes an extragalactic origin for the astrophysical neutrinos and hierarchical pseudo-Dirac mass spectrum. In case the neutrino sources are known in the future, such bounds can potentially improve by up to five orders of magnitude, reaching $\delta m^2_3 \lesssim 10^{-17}$ $\text{eV}^2$.
[ { "created": "Fri, 21 Jun 2024 18:05:22 GMT", "version": "v1" }, { "created": "Thu, 1 Aug 2024 01:39:29 GMT", "version": "v2" } ]
2024-08-02
[ [ "Fong", "Chee Sheng", "" ], [ "Porto", "Yago", "" ] ]
The three Standard Model neutrinos can have Majorana mass or strictly Dirac mass, but both scenarios are practically indistinguishable in neutrino oscillation experiments. If they are pseudo-Dirac, however, there will be new mass splittings among the pseudo-Dirac pairs, potentially leaving traces in neutrino oscillation phenomena. In this work, we use flavor ratios of astrophysical neutrinos to discriminate different possible mass spectra of pseudo-Dirac neutrinos. We show that it will be possible to impose robust bounds of order $\delta m^2_3 \lesssim 10^{-12}$ $\text{eV}^2$ on the new mass squared splitting involving the third pseudo-Dirac mass eigenstates (those with the least electron flavor composition) with the future experiment IceCube-Gen2. The derived sensitivity is robust because it only assumes an extragalactic origin for the astrophysical neutrinos and hierarchical pseudo-Dirac mass spectrum. In case the neutrino sources are known in the future, such bounds can potentially improve by up to five orders of magnitude, reaching $\delta m^2_3 \lesssim 10^{-17}$ $\text{eV}^2$.
1404.2404
Mikko Laine
B.B. Brandt, A. Francis, M. Laine, H.B. Meyer
A relation between screening masses and real-time rates
32 pages. v2: clarifications added, typos corrected; published version
JHEP 1405 (2014) 117
10.1007/JHEP05(2014)117
MITP/14-025
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Thermal screening masses related to the conserved vector current are determined for the case that the current carries a non-zero Matsubara frequency, both in a weak-coupling approach and through lattice QCD. We point out that such screening masses are sensitive to the same infrared physics as light-cone real-time rates. In particular, on the perturbative side, the inhomogeneous Schrodinger equation determining screening correlators is shown to have the same general form as the equation implementing LPM resummation for the soft-dilepton and photon production rates from a hot QCD plasma. The static potential appearing in the equation is identical to that whose soft part has been determined up to NLO and on the lattice in the context of jet quenching. Numerical results based on this potential suggest that screening masses overshoot the free results (multiples of 2piT) more strongly than at zero Matsubara frequency. Four-dimensional lattice simulations in two-flavour QCD at temperatures of 250 and 340 MeV confirm the non-static screening masses at the 10% level. Overall our results lend support to studies of jet quenching based on the same potential at T > 250 MeV.
[ { "created": "Wed, 9 Apr 2014 09:33:19 GMT", "version": "v1" }, { "created": "Wed, 28 May 2014 12:47:29 GMT", "version": "v2" } ]
2015-06-19
[ [ "Brandt", "B. B.", "" ], [ "Francis", "A.", "" ], [ "Laine", "M.", "" ], [ "Meyer", "H. B.", "" ] ]
Thermal screening masses related to the conserved vector current are determined for the case that the current carries a non-zero Matsubara frequency, both in a weak-coupling approach and through lattice QCD. We point out that such screening masses are sensitive to the same infrared physics as light-cone real-time rates. In particular, on the perturbative side, the inhomogeneous Schrodinger equation determining screening correlators is shown to have the same general form as the equation implementing LPM resummation for the soft-dilepton and photon production rates from a hot QCD plasma. The static potential appearing in the equation is identical to that whose soft part has been determined up to NLO and on the lattice in the context of jet quenching. Numerical results based on this potential suggest that screening masses overshoot the free results (multiples of 2piT) more strongly than at zero Matsubara frequency. Four-dimensional lattice simulations in two-flavour QCD at temperatures of 250 and 340 MeV confirm the non-static screening masses at the 10% level. Overall our results lend support to studies of jet quenching based on the same potential at T > 250 MeV.
1709.01945
Andre J. Scaffidi
Juan Herrero-Garcia, Andre Scaffidi, Martin White and Anthony G. Williams
On the direct detection of multi-component dark matter: sensitivity studies and parameter estimation
Minor changes. Matches published version in JCAP
null
10.1088/1475-7516/2017/11/021
ADP-17-33/T1039
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the case of multi-component dark matter, in particular how direct detection signals are modified in the presence of several stable weakly-interacting-massive particles. Assuming a positive signal in a future direct detection experiment, stemming from two dark matter components, we study the region in parameter space where it is possible to distinguish a one from a two-component dark matter spectrum. First, we leave as free parameters the two dark matter masses and show that the two hypotheses can be significantly discriminated for a range of dark matter masses with their splitting being the critical factor. We then investigate how including the effects of different interaction strengths, local densities or velocity dispersions for the two components modifies these conclusions. We also consider the case of isospin-violating couplings. In all scenarios, we show results for various types of nuclei both for elastic spin-independent and spin-dependent interactions. Finally, assuming that the two-component hypothesis is confirmed, we quantify the accuracy with which the parameters can be extracted and discuss the different degeneracies that occur. This includes studying the case in which only a single experiment observes a signal, and also the scenario of having two signals from two different experiments, in which case the ratios of the couplings to neutrons and protons may also be extracted.
[ { "created": "Wed, 6 Sep 2017 18:01:11 GMT", "version": "v1" }, { "created": "Sat, 9 Sep 2017 19:18:47 GMT", "version": "v2" }, { "created": "Wed, 15 Nov 2017 04:36:41 GMT", "version": "v3" } ]
2017-11-29
[ [ "Herrero-Garcia", "Juan", "" ], [ "Scaffidi", "Andre", "" ], [ "White", "Martin", "" ], [ "Williams", "Anthony G.", "" ] ]
We study the case of multi-component dark matter, in particular how direct detection signals are modified in the presence of several stable weakly-interacting-massive particles. Assuming a positive signal in a future direct detection experiment, stemming from two dark matter components, we study the region in parameter space where it is possible to distinguish a one from a two-component dark matter spectrum. First, we leave as free parameters the two dark matter masses and show that the two hypotheses can be significantly discriminated for a range of dark matter masses with their splitting being the critical factor. We then investigate how including the effects of different interaction strengths, local densities or velocity dispersions for the two components modifies these conclusions. We also consider the case of isospin-violating couplings. In all scenarios, we show results for various types of nuclei both for elastic spin-independent and spin-dependent interactions. Finally, assuming that the two-component hypothesis is confirmed, we quantify the accuracy with which the parameters can be extracted and discuss the different degeneracies that occur. This includes studying the case in which only a single experiment observes a signal, and also the scenario of having two signals from two different experiments, in which case the ratios of the couplings to neutrons and protons may also be extracted.
0712.0257
Chong Sheng Li
Gao Xiangdong, Chong Sheng Li, Zhao Li, Hao Zhang
Contributions from SUSY-FCNC couplings to the interpretation of the HyperCP events for the decay \Sigma^+ \to p \mu^+ \mu^-
18 pages, 7 figures
Eur.Phys.J.C55:317-324,2008
10.1140/epjc/s10052-008-0580-z
null
hep-ph
null
The observation of three events for the decay $\Sigma^+ \to p \mu^+ \mu^-$ with a dimuon invariant mass of $214.3\pm0.5$MeV by the HyperCP collaboration imply that a new particle X may be needed to explain the observed dimuon invariant mass distribution. We show that there are regions in the SUSY-FCNC parameter space where the $A^0_1$ in the NMSSM can be used to explain the HyperCP events without contradicting all the existing constraints from the measurements of the kaon decays, and the constraints from the $K^0-\bar{K}^0$ mixing are automatically satisfied once the constraints from kaon decays are satisfied.
[ { "created": "Mon, 3 Dec 2007 10:56:58 GMT", "version": "v1" } ]
2008-11-26
[ [ "Xiangdong", "Gao", "" ], [ "Li", "Chong Sheng", "" ], [ "Li", "Zhao", "" ], [ "Zhang", "Hao", "" ] ]
The observation of three events for the decay $\Sigma^+ \to p \mu^+ \mu^-$ with a dimuon invariant mass of $214.3\pm0.5$MeV by the HyperCP collaboration imply that a new particle X may be needed to explain the observed dimuon invariant mass distribution. We show that there are regions in the SUSY-FCNC parameter space where the $A^0_1$ in the NMSSM can be used to explain the HyperCP events without contradicting all the existing constraints from the measurements of the kaon decays, and the constraints from the $K^0-\bar{K}^0$ mixing are automatically satisfied once the constraints from kaon decays are satisfied.
2102.08386
Yongcheng Wu
Tao Han, Shuailong Li, Shufang Su, Wei Su, Yongcheng Wu
Heavy Higgs Bosons in 2HDM at a Muon Collider
41 pages, 18 figures, comments are welcome; v2: match to published version
Phys. Rev. D 104, 055029 (2021)
10.1103/PhysRevD.104.055029
PITT-PACC-2102, ADP-21-2/T1149
hep-ph hep-ex
http://creativecommons.org/licenses/by-nc-nd/4.0/
We study the discovery potential of the non-Standard Model (SM) heavy Higgs bosons in the Two-Higgs-Doublet Models (2HDMs) at a multi-TeV muon collider and explore the discrimination power among different types of 2HDMs. We find that the pair production of the non-SM Higgs bosons via the universal gauge interactions is the dominant mechanism once above the kinematic threshold. Single Higgs boson production associated with a pair of heavy fermions could be important in the parameter region with enhanced Yukawa couplings. For both signal final states, $\mu^+\mu^-$ annihilation channels dominate over the vector boson fusion (VBF) processes, except at high center of mass energies where the VBF processes receive large logarithmic enhancement with the increase of energies. Single Higgs boson $s$-channel production in $\mu^+\mu^-$-annihilation via the radiative return can also be important for the Type-L 2HDM in the very large $\tan\beta$ region, extending the kinematic reach of the heavy Higgs boson mass to the collider energy. Considering both the production and decay of non-SM Higgs bosons, signals can be identified over the Standard Model backgrounds. With the pair production channels via annihilation, 95\% C.L. exclusion reaches in the Higgs mass up to the production mass threshold of $\sqrt{s}/2$ are possible when channels with different final states are combined. Including single production modes can extended the reach further. Different types of 2HDMs can be distinguishable for moderate and large values of $\tan\beta$.
[ { "created": "Tue, 16 Feb 2021 19:00:00 GMT", "version": "v1" }, { "created": "Tue, 1 Mar 2022 20:51:09 GMT", "version": "v2" } ]
2022-03-03
[ [ "Han", "Tao", "" ], [ "Li", "Shuailong", "" ], [ "Su", "Shufang", "" ], [ "Su", "Wei", "" ], [ "Wu", "Yongcheng", "" ] ]
We study the discovery potential of the non-Standard Model (SM) heavy Higgs bosons in the Two-Higgs-Doublet Models (2HDMs) at a multi-TeV muon collider and explore the discrimination power among different types of 2HDMs. We find that the pair production of the non-SM Higgs bosons via the universal gauge interactions is the dominant mechanism once above the kinematic threshold. Single Higgs boson production associated with a pair of heavy fermions could be important in the parameter region with enhanced Yukawa couplings. For both signal final states, $\mu^+\mu^-$ annihilation channels dominate over the vector boson fusion (VBF) processes, except at high center of mass energies where the VBF processes receive large logarithmic enhancement with the increase of energies. Single Higgs boson $s$-channel production in $\mu^+\mu^-$-annihilation via the radiative return can also be important for the Type-L 2HDM in the very large $\tan\beta$ region, extending the kinematic reach of the heavy Higgs boson mass to the collider energy. Considering both the production and decay of non-SM Higgs bosons, signals can be identified over the Standard Model backgrounds. With the pair production channels via annihilation, 95\% C.L. exclusion reaches in the Higgs mass up to the production mass threshold of $\sqrt{s}/2$ are possible when channels with different final states are combined. Including single production modes can extended the reach further. Different types of 2HDMs can be distinguishable for moderate and large values of $\tan\beta$.
hep-ph/9806422
Kurt Langfeld
Kurt Langfeld
Induced symmetry breaking and a new phase of hadronic matter at high density
6 pages, 5 figures, Talk presented at the workshop ''QCD at finite baryon density'', Zif, Bielefeld, April 27-30, 1998, submitted to Nucl. Phys. A
Nucl.Phys. A642 (1998) 96-101
10.1016/S0375-9474(98)00504-1
UNITU-THEP-10/98
hep-ph hep-lat
null
The notion induced symmetry breaking (ISB) is introduced as a generalization of the spontaneous symmetry breaking mechanism and is illustrated in a simple two flavor spin model. In the case of QCD at finite baryon density, I argue that the quark interaction induced by zero sound satisfies the prerequisites which are necessary for a ISB scenario. In this scenario, the quark condensate sharply drops at the critical value of the chemical potential in coincidence with a rapid increase of the baryon density. The spectrum of the light particles is discussed below and above this phase transition. The consequences of the ISB mechanism for heavy ion collisions are briefly addressed.
[ { "created": "Fri, 19 Jun 1998 12:38:47 GMT", "version": "v1" } ]
2009-10-31
[ [ "Langfeld", "Kurt", "" ] ]
The notion induced symmetry breaking (ISB) is introduced as a generalization of the spontaneous symmetry breaking mechanism and is illustrated in a simple two flavor spin model. In the case of QCD at finite baryon density, I argue that the quark interaction induced by zero sound satisfies the prerequisites which are necessary for a ISB scenario. In this scenario, the quark condensate sharply drops at the critical value of the chemical potential in coincidence with a rapid increase of the baryon density. The spectrum of the light particles is discussed below and above this phase transition. The consequences of the ISB mechanism for heavy ion collisions are briefly addressed.
0811.1850
Gert Aarts
Gert Aarts
Two complex problems on the lattice: transport coefficients and finite chemical potential
Invited talk at Strong and Electroweak Matter, Amsterdam, the Netherlands, 26-29 August 2008, 8 pages, 10 eps figures
null
10.1016/j.nuclphysa.2009.01.019
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After a few remarks about the problem of extracting transport coefficients from lattice QCD calculations, I report on recent developments in applying stochastic quantization and complex Langevin dynamics to field theories with a complex action due to a nonzero chemical potential. First results demonstrate that the sign problem poses no obstacle for this approach, even in the thermodynamic limit. I conclude with a comparison of two simple one-link models, describing a euclidean system at finite chemical potential and a Minkowski system in real time.
[ { "created": "Wed, 12 Nov 2008 09:57:53 GMT", "version": "v1" } ]
2009-11-13
[ [ "Aarts", "Gert", "" ] ]
After a few remarks about the problem of extracting transport coefficients from lattice QCD calculations, I report on recent developments in applying stochastic quantization and complex Langevin dynamics to field theories with a complex action due to a nonzero chemical potential. First results demonstrate that the sign problem poses no obstacle for this approach, even in the thermodynamic limit. I conclude with a comparison of two simple one-link models, describing a euclidean system at finite chemical potential and a Minkowski system in real time.
hep-ph/0203113
Yoshio Koide
Yoshio Koide and Ambar Ghosal
Radiatively Induced Neutrino Mass Matrix in a SUSY GUT Model with R-Parity Violation
In Section 3, the H_d^+ contributions are added
null
null
US-02-04R2
hep-ph
null
In order to evade the proton decay which appears when the Zee model is embedded into a SUSY GUT scenario with R-parity violation, a new idea based on a discrete Z_2 symmetry is proposed. Under the symmetry Z_2, the quark and lepton mass matrices are tightly constrained. The admissible form of the radiatively-induced neutrino mass matrix is investigated.
[ { "created": "Wed, 13 Mar 2002 10:56:00 GMT", "version": "v1" }, { "created": "Fri, 15 Mar 2002 10:57:21 GMT", "version": "v2" }, { "created": "Thu, 2 May 2002 09:13:20 GMT", "version": "v3" }, { "created": "Tue, 2 Jul 2002 02:33:34 GMT", "version": "v4" } ]
2009-09-29
[ [ "Koide", "Yoshio", "" ], [ "Ghosal", "Ambar", "" ] ]
In order to evade the proton decay which appears when the Zee model is embedded into a SUSY GUT scenario with R-parity violation, a new idea based on a discrete Z_2 symmetry is proposed. Under the symmetry Z_2, the quark and lepton mass matrices are tightly constrained. The admissible form of the radiatively-induced neutrino mass matrix is investigated.
2309.14238
Satyabrata Datta
Satyabrata Datta
Explaining PTA Data with Inflationary GWs in a PBH-Dominated Universe
16 pages, 3 figures
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We show that an ultralight primordial black hole (PBH) dominated phase makes blue-tilted inflationary gravitational waves (BGW) compatible with the recent detection of an nHz stochastic GW background by pulsar-timing arrays (PTAs), for high reheating temperatures. This PBH-dominated phase suppresses the BGW spectrum via entropy dilution and generates a new GW spectrum from PBH density fluctuations. This combined spectrum is detectable at ongoing and planned near-future GW detectors and exhibits a unique shape with a low-frequency peak explaining PTA data, a mid-range dip, and a sharp peak followed by a third peak at high-frequency. This distinctive shape sets it apart from spectra generated by other matter dominations or exotic physics. Therefore, while important for studying GWs in the nHz range, the recent PTA result also sets the stage for testing and constraining various well-studied mechanisms following a PBH domination, using low-frequency measurements and correlated observations of unique high-frequency GW spectral features.
[ { "created": "Mon, 25 Sep 2023 15:54:40 GMT", "version": "v1" } ]
2023-09-26
[ [ "Datta", "Satyabrata", "" ] ]
We show that an ultralight primordial black hole (PBH) dominated phase makes blue-tilted inflationary gravitational waves (BGW) compatible with the recent detection of an nHz stochastic GW background by pulsar-timing arrays (PTAs), for high reheating temperatures. This PBH-dominated phase suppresses the BGW spectrum via entropy dilution and generates a new GW spectrum from PBH density fluctuations. This combined spectrum is detectable at ongoing and planned near-future GW detectors and exhibits a unique shape with a low-frequency peak explaining PTA data, a mid-range dip, and a sharp peak followed by a third peak at high-frequency. This distinctive shape sets it apart from spectra generated by other matter dominations or exotic physics. Therefore, while important for studying GWs in the nHz range, the recent PTA result also sets the stage for testing and constraining various well-studied mechanisms following a PBH domination, using low-frequency measurements and correlated observations of unique high-frequency GW spectral features.
0805.1419
Lisheng Geng
L. S. Geng, J. Martin Camalich, L. Alvarez-Ruso, and M. J. Vicente Vacas
Leading SU(3)-breaking corrections to the baryon magnetic moments in Chiral Perturbation Theory
4 pages, 2 figures, accepted for publication in PRL
Phys.Rev.Lett.101:222002,2008
10.1103/PhysRevLett.101.222002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the baryon magnetic moments using covariant Chiral Perturbation Theory ($\chi$PT) within the Extended-on-mass-shell (EOMS) renormalization scheme. By fitting the two available low-energy constants (LECs), we improve the Coleman-Glashow description of the data when we include the leading SU(3) breaking effects coming from the lowest-order loops. This success is in dramatic contrast with previous attempts at the same order using Heavy Baryon (HB) $\chi$PT and covariant Infrared (IR) $\chi$PT. We also analyze the source of this improvement with particular attention on the comparison between the covariant results.
[ { "created": "Fri, 9 May 2008 20:28:23 GMT", "version": "v1" }, { "created": "Mon, 17 Nov 2008 15:52:35 GMT", "version": "v2" } ]
2008-12-18
[ [ "Geng", "L. S.", "" ], [ "Camalich", "J. Martin", "" ], [ "Alvarez-Ruso", "L.", "" ], [ "Vacas", "M. J. Vicente", "" ] ]
We calculate the baryon magnetic moments using covariant Chiral Perturbation Theory ($\chi$PT) within the Extended-on-mass-shell (EOMS) renormalization scheme. By fitting the two available low-energy constants (LECs), we improve the Coleman-Glashow description of the data when we include the leading SU(3) breaking effects coming from the lowest-order loops. This success is in dramatic contrast with previous attempts at the same order using Heavy Baryon (HB) $\chi$PT and covariant Infrared (IR) $\chi$PT. We also analyze the source of this improvement with particular attention on the comparison between the covariant results.
1011.6622
A. Tawfik
A. Tawfik (Egyptian Ctr. Theor. Phys., Cairo)
Matter-Antimatter Asymmetry in the Large Hadron Collider
9 pages, 5 eps-figures, revtex4-style
null
10.1007/s10773-011-1015-4
ECTP-2010-12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The matter-antimatter asymmetry is one of the greatest challenges in the modern physics. The universe including this paper and even the reader him(her)self seems to be built up of ordinary matter only. Theoretically, the well-known Sakharov's conditions remain the solid framework explaining the circumstances that matter became dominant against the antimatter while the universe cools down and/or expands. On the other hand, the standard model for elementary particles apparently prevents at least two conditions out of them. In this work, we introduce a systematic study of the antiparticle-to-particle ratios measured in various $NN$ and $AA$ collisions over the last three decades. It is obvious that the available experimental facilities turn to be able to perform nuclear collisions, in which the matter-antimatter asymmetry raises from $\sim 0%$ at AGS to $\sim 100%$ at LHC. Assuming that the final state of hadronization in the nuclear collisions takes place along the freezeout line, which is defined by a constant entropy density, various antiparticle-to-particle ratios are studied in framework of the hadron resonance gas (HRG) model. Implementing modified phase space and distribution function in the grand-canonical ensemble and taking into account the experimental acceptance, the ratios of antiparticle-to-particle over the whole range of center-of-mass-energies are very well reproduced by the HRG model. Furthermore, the antiproton-to-proton ratios measured by ALICE in $pp$ collisions is also very well described by the HRG model. It is likely to conclude that the LHC heavy-ion program will produce the same particle ratios as the $pp$ program implying the dynamics and evolution of the system would not depend on the initial conditions. The ratios of bosons and baryons get very close to unity indicating that the matter-antimatter asymmetry nearly vanishes at LHC.
[ { "created": "Tue, 30 Nov 2010 17:48:00 GMT", "version": "v1" } ]
2012-03-08
[ [ "Tawfik", "A.", "", "Egyptian Ctr. Theor. Phys., Cairo" ] ]
The matter-antimatter asymmetry is one of the greatest challenges in the modern physics. The universe including this paper and even the reader him(her)self seems to be built up of ordinary matter only. Theoretically, the well-known Sakharov's conditions remain the solid framework explaining the circumstances that matter became dominant against the antimatter while the universe cools down and/or expands. On the other hand, the standard model for elementary particles apparently prevents at least two conditions out of them. In this work, we introduce a systematic study of the antiparticle-to-particle ratios measured in various $NN$ and $AA$ collisions over the last three decades. It is obvious that the available experimental facilities turn to be able to perform nuclear collisions, in which the matter-antimatter asymmetry raises from $\sim 0%$ at AGS to $\sim 100%$ at LHC. Assuming that the final state of hadronization in the nuclear collisions takes place along the freezeout line, which is defined by a constant entropy density, various antiparticle-to-particle ratios are studied in framework of the hadron resonance gas (HRG) model. Implementing modified phase space and distribution function in the grand-canonical ensemble and taking into account the experimental acceptance, the ratios of antiparticle-to-particle over the whole range of center-of-mass-energies are very well reproduced by the HRG model. Furthermore, the antiproton-to-proton ratios measured by ALICE in $pp$ collisions is also very well described by the HRG model. It is likely to conclude that the LHC heavy-ion program will produce the same particle ratios as the $pp$ program implying the dynamics and evolution of the system would not depend on the initial conditions. The ratios of bosons and baryons get very close to unity indicating that the matter-antimatter asymmetry nearly vanishes at LHC.
2201.09645
Saiyad Ashanujjaman
Saiyad Ashanujjaman, Debajyoti Choudhury and Kirtiman Ghosh
Search for exotic leptons in final states with two or three leptons and fat-jets at 13 TeV LHC
26 pages, 9 figures, 10 tables
null
10.1007/JHEP04(2022)150
IP/BBSR/2021-7
hep-ph
http://creativecommons.org/licenses/by/4.0/
Exotic leptons in large gauge multiplets, appearing in many scenarios beyond the Standard Model (SM), can be produced at the LHC in pairs or association. Owing to their large masses, their eventual decay products -- SM leptons and bosons -- tend to be highly boosted, with the jets stemming from the SM bosons more likely to manifest themselves as a single fat-jet rather than two resolved ones. With the corresponding SM backgrounds being suppressed, final states with two or three leptons and one or two fat-jets are expected to be sensitive in probing exotic fermions much heavier than 1 TeV, and we propose and investigate an appropriate search strategy. To concentrate on the essential, we consider extensions of the SM by leptonic multiplets of a single kind (triplets, quadruplets or quintuplets), bearing in mind that such simplified models typically arise as low-energy limits of more ambitious scenarios addressing various lacunae of the SM. Performing a systematic and comprehensive study of nine such scenarios at the 13 TeV LHC, we find that the corresponding $5\sigma$ discovery reaches a range from 985 GeV to 1650 GeV (1345 GeV to 2020 GeV) for 300 (3000) fb$^{-1}$.
[ { "created": "Mon, 24 Jan 2022 13:06:38 GMT", "version": "v1" } ]
2022-05-11
[ [ "Ashanujjaman", "Saiyad", "" ], [ "Choudhury", "Debajyoti", "" ], [ "Ghosh", "Kirtiman", "" ] ]
Exotic leptons in large gauge multiplets, appearing in many scenarios beyond the Standard Model (SM), can be produced at the LHC in pairs or association. Owing to their large masses, their eventual decay products -- SM leptons and bosons -- tend to be highly boosted, with the jets stemming from the SM bosons more likely to manifest themselves as a single fat-jet rather than two resolved ones. With the corresponding SM backgrounds being suppressed, final states with two or three leptons and one or two fat-jets are expected to be sensitive in probing exotic fermions much heavier than 1 TeV, and we propose and investigate an appropriate search strategy. To concentrate on the essential, we consider extensions of the SM by leptonic multiplets of a single kind (triplets, quadruplets or quintuplets), bearing in mind that such simplified models typically arise as low-energy limits of more ambitious scenarios addressing various lacunae of the SM. Performing a systematic and comprehensive study of nine such scenarios at the 13 TeV LHC, we find that the corresponding $5\sigma$ discovery reaches a range from 985 GeV to 1650 GeV (1345 GeV to 2020 GeV) for 300 (3000) fb$^{-1}$.
hep-ph/0605049
Thomas Hahn
T. Hahn
SUSY Les Houches Accord 2 I/O made easy
21 pages, added the blocks for non-minimal sneutrino and slepton flavour mixing
null
null
MPP-2006-46
hep-ph
null
A library for reading and writing data in the SUSY Les Houches Accord 2 format is presented. The implementation is in native Fortran 77. The data are contained in a single array conveniently indexed by preprocessor statements.
[ { "created": "Thu, 4 May 2006 18:58:00 GMT", "version": "v1" }, { "created": "Wed, 18 Oct 2006 10:16:31 GMT", "version": "v2" } ]
2007-05-23
[ [ "Hahn", "T.", "" ] ]
A library for reading and writing data in the SUSY Les Houches Accord 2 format is presented. The implementation is in native Fortran 77. The data are contained in a single array conveniently indexed by preprocessor statements.
1703.07176
Takayasu Sekihara
Takayasu Sekihara (JAEA, Ibaraki), Tetsuo Hyodo (Kyoto U., Yukawa Inst., Kyoto), Daisuke Jido (Tokyo Metropolitan U.), Junko Yamagata-Sekihara (Kyoto Sangyo U.), Shigehiro Yasui (Tokyo Inst. Tech.)
Two-body Wave Functions, Compositeness, And The Internal Structure Of Dynamically Generated Resonances
8 pages, 2 eps figures, talk given at the International Nuclear Physics Conference 2016 (INPC2016), Adelaide, Australia, 11-16 Sep. 2016
null
null
null
hep-ph hep-ex nucl-ex nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, the compositeness, defined as the norm of a two-body wave function for bound and resonance states, has been investigated to discuss the internal structure of hadrons in terms of hadronic molecular components. From the studies of the compositeness, it has been clarified that the two-body wave function of a bound state can be extracted from the residue of the scattering amplitude at the bound state pole. Of special interest is that the two-body wave function from the scattering amplitude is automatically normalized. In particular, while the compositeness is unity for energy-independent interactions, it deviates from unity for energy-dependent interactions, which can be interpreted as a missing-channel contribution. In this manuscript, we show the formulation of the two-body wave function from the scattering amplitude, evaluate the compositeness for several dynamically generated resonances such as $f_{0} (980)$, $\Lambda (1405)$, and $\Xi (1690)$, and investigate their internal structure in terms of the hadronic molecular components.
[ { "created": "Tue, 21 Mar 2017 12:41:50 GMT", "version": "v1" } ]
2017-03-22
[ [ "Sekihara", "Takayasu", "", "JAEA, Ibaraki" ], [ "Hyodo", "Tetsuo", "", "Kyoto U., Yukawa\n Inst., Kyoto" ], [ "Jido", "Daisuke", "", "Tokyo Metropolitan U." ], [ "Yamagata-Sekihara", "Junko", "", "Kyoto Sangyo U." ], [ "Yasui", ...
Recently, the compositeness, defined as the norm of a two-body wave function for bound and resonance states, has been investigated to discuss the internal structure of hadrons in terms of hadronic molecular components. From the studies of the compositeness, it has been clarified that the two-body wave function of a bound state can be extracted from the residue of the scattering amplitude at the bound state pole. Of special interest is that the two-body wave function from the scattering amplitude is automatically normalized. In particular, while the compositeness is unity for energy-independent interactions, it deviates from unity for energy-dependent interactions, which can be interpreted as a missing-channel contribution. In this manuscript, we show the formulation of the two-body wave function from the scattering amplitude, evaluate the compositeness for several dynamically generated resonances such as $f_{0} (980)$, $\Lambda (1405)$, and $\Xi (1690)$, and investigate their internal structure in terms of the hadronic molecular components.
1207.1584
Hao Ma
N\'estor Armesto, Hao Ma, Mauricio Mart\'inez, Yacine Mehtar-Tani, Carlos A. Salgado
In-medium antenna radiation in t-channel
6 pages, Proceedings of QNP 2012, Ecole Polytechnique, Palaiseau, Paris, France
PoS QNP2012 (2012) 151
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The color coherence effects in the medium modification to the initial state radiation are studied via a simple setup which allows these effects to be pronounced. The medium-induced gluon radiation spectrum off a hard quark which suffers a highly virtual photon scattering and subsequently crosses a dilute QCD medium of finite size is obtained. The angular distribution of the medium-induced gluon radiation spectrum is modified when the interference contributions between the incoming and outgoing quarks at a finite scattering angle are included.
[ { "created": "Fri, 6 Jul 2012 11:06:54 GMT", "version": "v1" } ]
2012-11-08
[ [ "Armesto", "Néstor", "" ], [ "Ma", "Hao", "" ], [ "Martínez", "Mauricio", "" ], [ "Mehtar-Tani", "Yacine", "" ], [ "Salgado", "Carlos A.", "" ] ]
The color coherence effects in the medium modification to the initial state radiation are studied via a simple setup which allows these effects to be pronounced. The medium-induced gluon radiation spectrum off a hard quark which suffers a highly virtual photon scattering and subsequently crosses a dilute QCD medium of finite size is obtained. The angular distribution of the medium-induced gluon radiation spectrum is modified when the interference contributions between the incoming and outgoing quarks at a finite scattering angle are included.
hep-ph/0604055
Stefan Leupold
Stefan Leupold (Giessen Univ.)
Fate of QCD sum rules or fate of vector meson dominance in a nuclear medium
7 pages
null
null
null
hep-ph
null
A current-current correlator with the quantum numbers of the omega meson is studied in a nuclear medium. Using weighted finite energy sum rules and dispersion relations for the current-nucleon forward scattering amplitude it is shown that strict vector meson dominance and QCD sum rules are incompatible with each other. This implies that at least one of these concepts -- which are both very powerful in the vacuum -- has to fade in the nuclear environment.
[ { "created": "Thu, 6 Apr 2006 14:30:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Leupold", "Stefan", "", "Giessen Univ." ] ]
A current-current correlator with the quantum numbers of the omega meson is studied in a nuclear medium. Using weighted finite energy sum rules and dispersion relations for the current-nucleon forward scattering amplitude it is shown that strict vector meson dominance and QCD sum rules are incompatible with each other. This implies that at least one of these concepts -- which are both very powerful in the vacuum -- has to fade in the nuclear environment.
1701.04029
Xin-Qiang Li
Quan-Yi Hu, Xin-Qiang Li and Ya-Dong Yang
The $\Lambda_b\to \Lambda(\to p\pi^-)\mu^+\mu^-$ decay in the aligned two-Higgs-doublet model
26 pages, 2 figures, and 4 tables; More discussions added, final version published in the journal
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The rare baryonic decay $\Lambda_b\to \Lambda(\to p\pi^-)\mu^+\mu^-$ provides valuable complementary information compared to the corresponding mesonic $b\to s\mu^+\mu^-$ transition. In this paper, using the latest high-precision lattice QCD calculation of the $\Lambda_b\to\Lambda$ transition form factors, we study this interesting decay within the aligned two-Higgs-doublet model, paying particularly attention to effects of the chirality-flipped operators generated by the charged scalars. In order to extract the full set of angular coefficients in this decay, we consider the following ten angular observables that can be derived from the analysis of the subsequent parity-violating $\Lambda\to p\pi^-$ decay: the differential branching fraction ${\rm d}{\cal B}/{\rm d}q^2$, the longitudinal polarization fraction $F_L$, the lepton-, hadron- and combined lepton-hadron-side forward-backward asymmetries $A_{\rm FB}^\ell$, $A_{\rm FB}^\Lambda$ and $A_{\rm FB}^{\ell\Lambda}$, as well as the other five asymmetry observables $Y_i$~($i={\rm 2,\,3s,\,3sc,\,4s,\,4sc}$). Detailed numerical comparisons are made between the SM and NP values for these angular observables. It is found that, under the constraints from the inclusive $B\to X_s\gamma$ branching fraction and the latest global fit results of $b\to s\ell\ell$ data, the contributions of right-handed semileptonic operators $O^{\prime}_{9,10}$, besides reconciling the $P_5^{\prime}$ anomaly observed in $B^0\to K^{\ast 0}\mu^+\mu^-$ decay, could also enhance the values of ${\rm d}{\cal B}/{\rm d}q^2$ and $A_{\rm FB}^\ell$ in the bin $[15,20]~{\rm GeV}^2$, leading to results consistent with the current LHCb measurements.
[ { "created": "Sun, 15 Jan 2017 12:21:26 GMT", "version": "v1" }, { "created": "Fri, 19 May 2017 02:48:37 GMT", "version": "v2" } ]
2017-05-22
[ [ "Hu", "Quan-Yi", "" ], [ "Li", "Xin-Qiang", "" ], [ "Yang", "Ya-Dong", "" ] ]
The rare baryonic decay $\Lambda_b\to \Lambda(\to p\pi^-)\mu^+\mu^-$ provides valuable complementary information compared to the corresponding mesonic $b\to s\mu^+\mu^-$ transition. In this paper, using the latest high-precision lattice QCD calculation of the $\Lambda_b\to\Lambda$ transition form factors, we study this interesting decay within the aligned two-Higgs-doublet model, paying particularly attention to effects of the chirality-flipped operators generated by the charged scalars. In order to extract the full set of angular coefficients in this decay, we consider the following ten angular observables that can be derived from the analysis of the subsequent parity-violating $\Lambda\to p\pi^-$ decay: the differential branching fraction ${\rm d}{\cal B}/{\rm d}q^2$, the longitudinal polarization fraction $F_L$, the lepton-, hadron- and combined lepton-hadron-side forward-backward asymmetries $A_{\rm FB}^\ell$, $A_{\rm FB}^\Lambda$ and $A_{\rm FB}^{\ell\Lambda}$, as well as the other five asymmetry observables $Y_i$~($i={\rm 2,\,3s,\,3sc,\,4s,\,4sc}$). Detailed numerical comparisons are made between the SM and NP values for these angular observables. It is found that, under the constraints from the inclusive $B\to X_s\gamma$ branching fraction and the latest global fit results of $b\to s\ell\ell$ data, the contributions of right-handed semileptonic operators $O^{\prime}_{9,10}$, besides reconciling the $P_5^{\prime}$ anomaly observed in $B^0\to K^{\ast 0}\mu^+\mu^-$ decay, could also enhance the values of ${\rm d}{\cal B}/{\rm d}q^2$ and $A_{\rm FB}^\ell$ in the bin $[15,20]~{\rm GeV}^2$, leading to results consistent with the current LHCb measurements.
hep-ph/9307305
Daizo Mochinaga
Chuichiro Hattori, Masahisa Matsuda, Takeo Matsuoka, Daizo Mochinaga
The String Unufication of Gauge Cuoplings and Gauge Kinetic Mixings
27 pages, LaTeX, DPNU-93-16, AUE-03-93
Prog.Theor.Phys. 90 (1993) 895-910
10.1143/ptp/90.4.895
null
hep-ph
null
In the superstring models we have not only the complete {\bf 27} multiplets of $E_6$ but also extra incomplete $({\bf 27}+{\overline {\bf 27}})$ chiral supermultiplets being alive at low energies. Associated with these additional multiplets, when the gauge symmetry contains more than one $U(1)$ gauge group, there may exist gauge kinetic mixings among these $U(1)$ gauge groups. In such cases the effect of gauge kinetic mixings should be incorporated into the study of unification of gauge couplings. We study these interesting effects systematically in these models. The string threshold effect is also taken into account. It is found that in the four-generation models we do not have a advisable solution of string unification of gauge couplings consistent with experimental values at the electroweak scale. We also discuss the possible scenarios to solve this problem.
[ { "created": "Tue, 20 Jul 1993 06:28:46 GMT", "version": "v1" } ]
2017-02-01
[ [ "Hattori", "Chuichiro", "" ], [ "Matsuda", "Masahisa", "" ], [ "Matsuoka", "Takeo", "" ], [ "Mochinaga", "Daizo", "" ] ]
In the superstring models we have not only the complete {\bf 27} multiplets of $E_6$ but also extra incomplete $({\bf 27}+{\overline {\bf 27}})$ chiral supermultiplets being alive at low energies. Associated with these additional multiplets, when the gauge symmetry contains more than one $U(1)$ gauge group, there may exist gauge kinetic mixings among these $U(1)$ gauge groups. In such cases the effect of gauge kinetic mixings should be incorporated into the study of unification of gauge couplings. We study these interesting effects systematically in these models. The string threshold effect is also taken into account. It is found that in the four-generation models we do not have a advisable solution of string unification of gauge couplings consistent with experimental values at the electroweak scale. We also discuss the possible scenarios to solve this problem.
hep-ph/9902356
Sergey Goloskokov
S.V.Goloskokov
Spin Effects in Diffractive $J/\Psi$ Leptoproduction and Structure of Pomeron Coupling
20 pages, latex, 4 PS figures, revised version
Eur.Phys.J.C11:309-316,1999
10.1007/s100520050635
null
hep-ph
null
We calculate the cross section and the $A_{ll}$ asymmetry of the diffractive vector meson leptoproduction for a simple model of the pomeron coupling with the proton. It is found that the sensitivity of the spin--dependent cross section of the diffractive $J/\Psi$ production to the pomeron coupling structure is rather weak. The conclusion is made that it will be difficult to study the structure of the pomeron coupling with the proton in future polarized diffractive experiments on the $J/\Psi$ production.
[ { "created": "Tue, 16 Feb 1999 12:35:54 GMT", "version": "v1" }, { "created": "Tue, 27 Apr 1999 12:04:21 GMT", "version": "v2" } ]
2011-09-13
[ [ "Goloskokov", "S. V.", "" ] ]
We calculate the cross section and the $A_{ll}$ asymmetry of the diffractive vector meson leptoproduction for a simple model of the pomeron coupling with the proton. It is found that the sensitivity of the spin--dependent cross section of the diffractive $J/\Psi$ production to the pomeron coupling structure is rather weak. The conclusion is made that it will be difficult to study the structure of the pomeron coupling with the proton in future polarized diffractive experiments on the $J/\Psi$ production.
hep-ph/0210363
Stefan Hesselbach
S. Hesselbach and F. Franke
Singlino-dominated Neutralinos in Extended Supersymmetric Models
7 pages, LaTeX, 3 eps figures; contribution to the proceedings of the 10th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 02), DESY, Hamburg, Germany, 17 - 23 June 2002
null
null
UWThPh-2002-32, WUE-ITP-2002-028
hep-ph
null
We adopt the SUSY benchmark scenario SPS 1a in supersymmetric models where the Higgs sector is extended by singlet superfields. We consider light neutralinos with dominant singlino character whose couplings are generally suppressed. The cross sections for direct production of the singlino-dominated neutralinos can be of the order of several fb for singlet vevs of some TeV. Hence even exotic neutralinos which are not the LSP and are omitted in the decay chains of the other supersymmetric particles may be visible at a high luminosity linear e^+e^- collider. If, however, the LSP is singlino-dominated the decay width of the NLSP can be very small and displaced vertices exist for large singlet vacuum expectation values.
[ { "created": "Sat, 26 Oct 2002 16:48:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hesselbach", "S.", "" ], [ "Franke", "F.", "" ] ]
We adopt the SUSY benchmark scenario SPS 1a in supersymmetric models where the Higgs sector is extended by singlet superfields. We consider light neutralinos with dominant singlino character whose couplings are generally suppressed. The cross sections for direct production of the singlino-dominated neutralinos can be of the order of several fb for singlet vevs of some TeV. Hence even exotic neutralinos which are not the LSP and are omitted in the decay chains of the other supersymmetric particles may be visible at a high luminosity linear e^+e^- collider. If, however, the LSP is singlino-dominated the decay width of the NLSP can be very small and displaced vertices exist for large singlet vacuum expectation values.
2308.09669
Matthew Kirk
Matthew Kirk
Cabibbo angle anomalies and a global fit to vector-like quarks
Prepared for the FPCP 2023 proceedings (v2: added reference, v3: explained acronyms, corrected "SU2 singlet Q" -> "SU2 doublet Q")
PoS(FPCP2023)059
10.22323/1.445.0059
null
hep-ph hep-ex
http://creativecommons.org/licenses/by-nc-nd/4.0/
The most recent determinations of $V_{ud}$ from superallowed beta decays lead to a discrepancy when compared to the value implied by mesonic CKM measurements combined with CKM unitarity. On top of this, improved precision in lattice QCD calculations have revealed another discrepancy between the $V_{us}$ determinations from kaon and pion semi-leptonic decays. The combination of these can be referred to as the Cabibbo angle anomaly, which we find has a significance of around $3\,\sigma$. After summarising the current state of these issues, I will talk about new physics models that modify semi-leptonic decays as potential explanations, and why vector-like quarks in particular appear the most promising candidates. I will then discuss the results of a global fit to various vector-like quark models, and how other constraints are important in determining the most likely explanation. Finally I will touch on future experiments that could shed further light on the situation.
[ { "created": "Fri, 18 Aug 2023 16:41:04 GMT", "version": "v1" }, { "created": "Mon, 4 Sep 2023 09:47:04 GMT", "version": "v2" }, { "created": "Mon, 30 Oct 2023 10:22:39 GMT", "version": "v3" } ]
2023-10-31
[ [ "Kirk", "Matthew", "" ] ]
The most recent determinations of $V_{ud}$ from superallowed beta decays lead to a discrepancy when compared to the value implied by mesonic CKM measurements combined with CKM unitarity. On top of this, improved precision in lattice QCD calculations have revealed another discrepancy between the $V_{us}$ determinations from kaon and pion semi-leptonic decays. The combination of these can be referred to as the Cabibbo angle anomaly, which we find has a significance of around $3\,\sigma$. After summarising the current state of these issues, I will talk about new physics models that modify semi-leptonic decays as potential explanations, and why vector-like quarks in particular appear the most promising candidates. I will then discuss the results of a global fit to various vector-like quark models, and how other constraints are important in determining the most likely explanation. Finally I will touch on future experiments that could shed further light on the situation.
2308.07257
Shao-Jiang Wang
Song He, Li Li, Sai Wang, Shao-Jiang Wang
Constraints on holographic QCD phase transitions from PTA observations
v1, 9 pages, 4 figures; v2, references added; v2, 10 pages, 4 figures, references updated, minor revision, accepted for publication in Sci. China Phys. Mech. Astron
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition, yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition (FoPT) left undetermined. At specific baryon chemical potential, the first-order QCD phase transition agrees with the observational constraint of baryon asymmetry. It, therefore, provides a scenario for phase transition gravitational waves (GWs) within the Standard Model of particle physics. If these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array (PTA) observations, the duration of this FoPT can be well constrained, and the associated primordial black holes are still allowed by current observations.
[ { "created": "Mon, 14 Aug 2023 16:41:35 GMT", "version": "v1" }, { "created": "Sun, 3 Sep 2023 17:00:51 GMT", "version": "v2" }, { "created": "Mon, 22 Jul 2024 07:16:17 GMT", "version": "v3" } ]
2024-07-23
[ [ "He", "Song", "" ], [ "Li", "Li", "" ], [ "Wang", "Sai", "" ], [ "Wang", "Shao-Jiang", "" ] ]
The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition, yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition (FoPT) left undetermined. At specific baryon chemical potential, the first-order QCD phase transition agrees with the observational constraint of baryon asymmetry. It, therefore, provides a scenario for phase transition gravitational waves (GWs) within the Standard Model of particle physics. If these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array (PTA) observations, the duration of this FoPT can be well constrained, and the associated primordial black holes are still allowed by current observations.
1806.04696
Eleni Vryonidou
V. Hirschi, F. Maltoni, I. Tsinikos, E. Vryonidou
Constraining anomalous gluon self-interactions at the LHC: a reappraisal
published version, reference added
null
10.1007/JHEP07(2018)093
CP3-18-35, TUM-HEP-1145/18, CERN-TH-2018-136
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Anomalous self-interactions of non-abelian gauge fields can be described by higher dimensional operators featuring gauge-invariant combinations of the field strengths. In the case of QCD, the gluon self-interactions start to be modified at dimension six by operators of the type $GGG$, with $G$ the gluon field strength tensor, possibly leading to deviations in all observables and measurements that probe strong interactions at very small distances. In this work we consider the sensitivity to the triple gluon operator of a series of observables at the LHC in di-jet, three- and multi-jet final states and heavy-quark production. We critically re-examine the robustness of long-standing as well as more recent proposals addressing issues such as the validity of the EFT expansion and the impact of higher order QCD corrections. Our results support the conclusion that multi-jet observables can reliably bound these anomalous interactions to the level that their impact on other key observables at the LHC, involving for example top quark and Higgs production, can be safely neglected. We also highlight the potential of using previously suggested angular observables in three-jet events at the LHC to further constrain these interactions.
[ { "created": "Tue, 12 Jun 2018 18:03:52 GMT", "version": "v1" }, { "created": "Tue, 4 Sep 2018 15:27:14 GMT", "version": "v2" } ]
2018-09-05
[ [ "Hirschi", "V.", "" ], [ "Maltoni", "F.", "" ], [ "Tsinikos", "I.", "" ], [ "Vryonidou", "E.", "" ] ]
Anomalous self-interactions of non-abelian gauge fields can be described by higher dimensional operators featuring gauge-invariant combinations of the field strengths. In the case of QCD, the gluon self-interactions start to be modified at dimension six by operators of the type $GGG$, with $G$ the gluon field strength tensor, possibly leading to deviations in all observables and measurements that probe strong interactions at very small distances. In this work we consider the sensitivity to the triple gluon operator of a series of observables at the LHC in di-jet, three- and multi-jet final states and heavy-quark production. We critically re-examine the robustness of long-standing as well as more recent proposals addressing issues such as the validity of the EFT expansion and the impact of higher order QCD corrections. Our results support the conclusion that multi-jet observables can reliably bound these anomalous interactions to the level that their impact on other key observables at the LHC, involving for example top quark and Higgs production, can be safely neglected. We also highlight the potential of using previously suggested angular observables in three-jet events at the LHC to further constrain these interactions.
1906.10024
Francesco Giacosa
Francesco Giacosa and Giuseppe Pagliara
Measurement of the neutron lifetime and inverse quantum Zeno effect
8 pages, 2 figure. To appear in PRD
Phys. Rev. D 101, 056003 (2020)
10.1103/PhysRevD.101.056003
null
hep-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum mechanics predicts that the decay rate of unstable systems could be effectively modified by the process of the measurement of the survival probability. Depending on the intrinsic properties of the unstable system and the experimental setup for the observation, one could obtain the so called (direct) quantum Zeno and inverse quantum Zeno effects corresponding to a slowing down or a speeding up of the decay, respectively. We argue that the inverse quantum Zeno effect is in principle detectable at a percent level for the neutron decay in experiments with trapped ultracold neutrons. Conversely, this effect is basically undetectable in experiments in which the neutron lifetime is measured by measuring the decays of beams of neutrons. As a test of our claim, we propose a simple qualitative correlation between the number of neutrons in the trap and the neutron lifetime: the larger the number, the faster the decay. Finally we discuss also the presently available measurements of the neutron lifetime and address the issue of the possible discrepancy that has been reported among the results obtained by the different experimental techniques.
[ { "created": "Mon, 24 Jun 2019 15:22:41 GMT", "version": "v1" }, { "created": "Sat, 22 Feb 2020 14:13:41 GMT", "version": "v2" } ]
2020-03-11
[ [ "Giacosa", "Francesco", "" ], [ "Pagliara", "Giuseppe", "" ] ]
Quantum mechanics predicts that the decay rate of unstable systems could be effectively modified by the process of the measurement of the survival probability. Depending on the intrinsic properties of the unstable system and the experimental setup for the observation, one could obtain the so called (direct) quantum Zeno and inverse quantum Zeno effects corresponding to a slowing down or a speeding up of the decay, respectively. We argue that the inverse quantum Zeno effect is in principle detectable at a percent level for the neutron decay in experiments with trapped ultracold neutrons. Conversely, this effect is basically undetectable in experiments in which the neutron lifetime is measured by measuring the decays of beams of neutrons. As a test of our claim, we propose a simple qualitative correlation between the number of neutrons in the trap and the neutron lifetime: the larger the number, the faster the decay. Finally we discuss also the presently available measurements of the neutron lifetime and address the issue of the possible discrepancy that has been reported among the results obtained by the different experimental techniques.
1302.7260
C\'edric Weiland
Cedric Weiland
Enhanced lepton flavour violation in the supersymmetric inverse seesaw
8 pages, 4 figures, Proceedings of Discrete 2012, Published under licence in Journal of Physics: Conference Series (JPCS) by IOP Publishing Ltd, v2 includes a preprint number
J.Phys.Conf.Ser. 447 (2013) 012037
10.1088/1742-6596/447/1/012037
LPT-Orsay-13-106
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In minimal supersymmetric seesaw models, the contribution to lepton flavour violation from Z-penguins is usually negligible. In this study, we consider the supersymmetric inverse seesaw and show that, in this case, the Z-penguin contribution dominates in several lepton flavour violating observables due to the low scale of the inverse seesaw mechanism. Among the observables considered, we find that the most constraining one is the muon to electron conversion rate which is already restricting the otherwise allowed parameter space of the model. Moreover, in this framework, the Z-penguins exhibit a non-decoupling behaviour, which has previously been noticed in lepton flavour violating Higgs decays.
[ { "created": "Thu, 28 Feb 2013 17:10:59 GMT", "version": "v1" }, { "created": "Thu, 19 Dec 2013 18:00:54 GMT", "version": "v2" } ]
2013-12-20
[ [ "Weiland", "Cedric", "" ] ]
In minimal supersymmetric seesaw models, the contribution to lepton flavour violation from Z-penguins is usually negligible. In this study, we consider the supersymmetric inverse seesaw and show that, in this case, the Z-penguin contribution dominates in several lepton flavour violating observables due to the low scale of the inverse seesaw mechanism. Among the observables considered, we find that the most constraining one is the muon to electron conversion rate which is already restricting the otherwise allowed parameter space of the model. Moreover, in this framework, the Z-penguins exhibit a non-decoupling behaviour, which has previously been noticed in lepton flavour violating Higgs decays.
0909.3514
Christoph Weniger
Alejandro Ibarra, David Tran and Christoph Weniger
Detecting Gamma-Ray Anisotropies from Decaying Dark Matter: Prospects for Fermi LAT
16 pages, 9 figures, minor revisions, references added, version accepted by Phys. Rev. D
Phys.Rev.D81:023529,2010
10.1103/PhysRevD.81.023529
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Decaying dark matter particles could be indirectly detected as an excess over a simple power law in the energy spectrum of the diffuse extragalactic gamma-ray background. Furthermore, since the Earth is not located at the center of the Galactic dark matter halo, the exotic contribution from dark matter decay to the diffuse gamma-ray flux is expected to be anisotropic, offering a complementary method for the indirect search for decaying dark matter particles. In this paper we discuss in detail the expected dipole-like anisotropies in the dark matter signal, taking also into account the radiation from inverse Compton scattering of electrons and positrons from dark matter decay. A different source for anisotropies in the gamma-ray flux are the dark matter density fluctuations on cosmic scales. We calculate the corresponding angular power spectrum of the gamma-ray flux and comment on observational prospects. Finally, we calculate the expected anisotropies for the decaying dark matter scenarios that can reproduce the electron/positron excesses reported by PAMELA and the Fermi LAT, and we estimate the prospects for detecting the predicted gamma-ray anisotropy in the near future.
[ { "created": "Fri, 18 Sep 2009 19:55:42 GMT", "version": "v1" }, { "created": "Mon, 14 Dec 2009 20:47:43 GMT", "version": "v2" } ]
2014-11-20
[ [ "Ibarra", "Alejandro", "" ], [ "Tran", "David", "" ], [ "Weniger", "Christoph", "" ] ]
Decaying dark matter particles could be indirectly detected as an excess over a simple power law in the energy spectrum of the diffuse extragalactic gamma-ray background. Furthermore, since the Earth is not located at the center of the Galactic dark matter halo, the exotic contribution from dark matter decay to the diffuse gamma-ray flux is expected to be anisotropic, offering a complementary method for the indirect search for decaying dark matter particles. In this paper we discuss in detail the expected dipole-like anisotropies in the dark matter signal, taking also into account the radiation from inverse Compton scattering of electrons and positrons from dark matter decay. A different source for anisotropies in the gamma-ray flux are the dark matter density fluctuations on cosmic scales. We calculate the corresponding angular power spectrum of the gamma-ray flux and comment on observational prospects. Finally, we calculate the expected anisotropies for the decaying dark matter scenarios that can reproduce the electron/positron excesses reported by PAMELA and the Fermi LAT, and we estimate the prospects for detecting the predicted gamma-ray anisotropy in the near future.
hep-ph/9811283
null
T. Csorgo and J. Zimanyi
On Bose-condensation of wave-packets in heavy ion collisions
10 pages, uses sprocl.sty and epsf.sty with 4 figures. Invited talk of J. Zimanyi at Correlations and Fluctuations'98: 8-th International Workshop on Multiparticle Production, Matrahaza, Hungary, June 1998. (World Scientific, Singapore, 1999, ed. T. Csorgo, S. Hegyi, R. C. Hwa and G. Jancso)
Proc. CF'98 (WSCI 1999, ed. T. Csorgo et al.) p. 56
null
KFKI - 1998 - 04 / A
hep-ph
null
A recently obtained exact analytic solution to the wave-packet version of the pion-laser model is presented. In the rare gas limit, a thermal behaviour is found while the dense gas limiting case corresponds to Bose-Einstein condensation of wave-packets to the wave-packet mode with the smallest possible energy.
[ { "created": "Mon, 9 Nov 1998 22:18:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Csorgo", "T.", "" ], [ "Zimanyi", "J.", "" ] ]
A recently obtained exact analytic solution to the wave-packet version of the pion-laser model is presented. In the rare gas limit, a thermal behaviour is found while the dense gas limiting case corresponds to Bose-Einstein condensation of wave-packets to the wave-packet mode with the smallest possible energy.
2110.14084
Manfred Kraus
Manfred Kraus
On the modeling of $t\bar{t}W^\pm$ signatures at the LHC
9 pages, 5 figures, contribution to the Proceedings of the 15th International Symposium on Radiative Corrections (RADCOR) and the XIX Workshop on Radiative Corrections for the LHC and Future Colliders (LoopFest), 2021
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss our recent progress on improving the theoretical description of the $pp \to t\bar{t}W^\pm$ process with particular focus on fiducial signatures that include top-quark decays. We employ a wide range of techniques from parton shower matching, narrow width approximation to full off-shell computations to assess the importance of the different modeling approaches.
[ { "created": "Tue, 26 Oct 2021 23:25:52 GMT", "version": "v1" } ]
2021-10-28
[ [ "Kraus", "Manfred", "" ] ]
We discuss our recent progress on improving the theoretical description of the $pp \to t\bar{t}W^\pm$ process with particular focus on fiducial signatures that include top-quark decays. We employ a wide range of techniques from parton shower matching, narrow width approximation to full off-shell computations to assess the importance of the different modeling approaches.
2201.06179
Radovan Dermisek
Radovan Dermisek
Muon g-2 and other observables in models with extended Higgs and matter sectors
5 pages, 6 figures, contribution to the proceedings of the 20th Lomonosov conference, Moscow, August 2021
null
10.3103/S0027134922020278
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
I review possible explanations of the muon g-2 anomaly in models with extended Higgs and matter sectors, focusing on extensions of the standard model and the two Higgs doublet model with vectorlike leptons. Predictions of these models, namely the modifications of muon Yukawa and gauge couplings, that can be searched for at the LHC and future colliders, are summarized. I also discuss striking predictions for di-Higgs and tri-Higgs signals at a muon collider that can be tested even at very low energies. Furthermore, I briefly comment on other interesting features and signatures of models with extended Higgs sector and vectorlike matter.
[ { "created": "Mon, 17 Jan 2022 02:17:26 GMT", "version": "v1" } ]
2022-09-21
[ [ "Dermisek", "Radovan", "" ] ]
I review possible explanations of the muon g-2 anomaly in models with extended Higgs and matter sectors, focusing on extensions of the standard model and the two Higgs doublet model with vectorlike leptons. Predictions of these models, namely the modifications of muon Yukawa and gauge couplings, that can be searched for at the LHC and future colliders, are summarized. I also discuss striking predictions for di-Higgs and tri-Higgs signals at a muon collider that can be tested even at very low energies. Furthermore, I briefly comment on other interesting features and signatures of models with extended Higgs sector and vectorlike matter.
2308.03959
A. A. Natale
A. A. Natale
A natural QCD infrared cutoff
10 pages, 3 figures, to appear in the Festschrift for Ruben Aldrovandi
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We briefly discuss some results obtained recently about dynamical gluon mass generation. We comment that this mass provides a natural QCD infrared cutoff and also implies an infrared finite coupling constant. We also discuss the phenomenological applications of these results and how they can be treated in the context of the so-called Dynamical Perturbation Theory.
[ { "created": "Mon, 7 Aug 2023 23:51:46 GMT", "version": "v1" } ]
2023-08-09
[ [ "Natale", "A. A.", "" ] ]
We briefly discuss some results obtained recently about dynamical gluon mass generation. We comment that this mass provides a natural QCD infrared cutoff and also implies an infrared finite coupling constant. We also discuss the phenomenological applications of these results and how they can be treated in the context of the so-called Dynamical Perturbation Theory.
hep-ph/0006138
Sudhir K. Vempati
Anjan S. Joshipura, Rishikesh D. Vaidya and Sudhir K. Vempati
U(1) symmetry and R parity violation
20 pages Latex, No figures
Phys.Rev. D62 (2000) 093020
10.1103/PhysRevD.62.093020
null
hep-ph
null
The patterns of $R$ violation resulting from imposition of a gauged U(1) horizontal symmetry on the minimal supersymmetric standard model are systematically analyzed. We concentrate on class of models with integer U(1) charges chosen to reproduce the quark masses and mixings as well as charged lepton masses exactly or approximately. The U(1) charges are further restricted by the requirement that very large bilinear lepton number violating terms should not be allowed in the superpotential. It is shown that this leads to severely constrained patterns of trilinear interactions. Specifically, only choice compatible with phenomenological restrictions is the one in which all the trilinear $\lambda'_{ijk}$ and all but at most two trilinear $\lambda_{ijk}$ couplings vanish or are enormously suppressed. The U(1) symmetry can allow effective generation of bilinear lepton number violating parameters through terms in the Kahler potential. Resulting models are identified and structure of neutrino masses in some of these is briefly discussed.
[ { "created": "Tue, 13 Jun 2000 17:22:18 GMT", "version": "v1" } ]
2009-10-31
[ [ "Joshipura", "Anjan S.", "" ], [ "Vaidya", "Rishikesh D.", "" ], [ "Vempati", "Sudhir K.", "" ] ]
The patterns of $R$ violation resulting from imposition of a gauged U(1) horizontal symmetry on the minimal supersymmetric standard model are systematically analyzed. We concentrate on class of models with integer U(1) charges chosen to reproduce the quark masses and mixings as well as charged lepton masses exactly or approximately. The U(1) charges are further restricted by the requirement that very large bilinear lepton number violating terms should not be allowed in the superpotential. It is shown that this leads to severely constrained patterns of trilinear interactions. Specifically, only choice compatible with phenomenological restrictions is the one in which all the trilinear $\lambda'_{ijk}$ and all but at most two trilinear $\lambda_{ijk}$ couplings vanish or are enormously suppressed. The U(1) symmetry can allow effective generation of bilinear lepton number violating parameters through terms in the Kahler potential. Resulting models are identified and structure of neutrino masses in some of these is briefly discussed.
0907.0562
Poonam Mehta
Poonam Mehta (RRI)
Geometric imprint of CP violation in two flavor neutrino oscillations
v2 : modified version with new references
null
null
null
hep-ph hep-ex hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In vacuum or constant density matter, the two flavor neutrino oscillation formulae are insensitive to the presence of CP violating phases owing to the fact that the CP phase can be gauged away. In sharp contrast to the above case, we show that the CP violating phases can not be gauged away in presence of adiabatically changing background density accompanied by varying CP phases. We present a pure geometric visualization of this fact by exploiting Pancharatnam's prescription of cyclic quantum projections. Consequently the topological phase obtained in Phys. Rev. D 79, 096013 (2009) can become geometric if CP violation occurs in a varying density medium.
[ { "created": "Fri, 3 Jul 2009 09:48:59 GMT", "version": "v1" }, { "created": "Fri, 5 Feb 2010 12:15:15 GMT", "version": "v2" } ]
2010-02-05
[ [ "Mehta", "Poonam", "", "RRI" ] ]
In vacuum or constant density matter, the two flavor neutrino oscillation formulae are insensitive to the presence of CP violating phases owing to the fact that the CP phase can be gauged away. In sharp contrast to the above case, we show that the CP violating phases can not be gauged away in presence of adiabatically changing background density accompanied by varying CP phases. We present a pure geometric visualization of this fact by exploiting Pancharatnam's prescription of cyclic quantum projections. Consequently the topological phase obtained in Phys. Rev. D 79, 096013 (2009) can become geometric if CP violation occurs in a varying density medium.
1802.03566
De-Min Li
Shi-Chen Xue, Guan-Ying Wang, Guan-Nan Li, En Wang, and De-Min Li
The possible members of the $5^1S_0$ meson nonet
10 pages, 5 figures, version accepted by Eur. Phys. J. C
null
10.1140/epjc/s10052-018-5961-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strong decays of the $5^1S_0$ $q\bar{q}$ states are evaluated in the $^3P_0$ model with two types of space wave functions. Comparing the model expectations with the experimental data for the $\pi(2360)$, $\eta(2320)$, $X(2370)$, and $X(2500)$, we suggest that the $\pi(2360)$, $\eta(2320)$, and $X(2500)$ can be assigned as the members of the $5^1S_0$ meson nonet, while the $5^1S_0$ assignment for the $X(2370)$ is not favored by its width. The $5^1S_0$ kaon is predicted to have a mass of about 2418 MeV and a width of about 163 MeV or 225 MeV.
[ { "created": "Sat, 10 Feb 2018 10:36:13 GMT", "version": "v1" }, { "created": "Tue, 13 Feb 2018 11:58:57 GMT", "version": "v2" }, { "created": "Fri, 1 Jun 2018 03:30:14 GMT", "version": "v3" } ]
2018-07-04
[ [ "Xue", "Shi-Chen", "" ], [ "Wang", "Guan-Ying", "" ], [ "Li", "Guan-Nan", "" ], [ "Wang", "En", "" ], [ "Li", "De-Min", "" ] ]
The strong decays of the $5^1S_0$ $q\bar{q}$ states are evaluated in the $^3P_0$ model with two types of space wave functions. Comparing the model expectations with the experimental data for the $\pi(2360)$, $\eta(2320)$, $X(2370)$, and $X(2500)$, we suggest that the $\pi(2360)$, $\eta(2320)$, and $X(2500)$ can be assigned as the members of the $5^1S_0$ meson nonet, while the $5^1S_0$ assignment for the $X(2370)$ is not favored by its width. The $5^1S_0$ kaon is predicted to have a mass of about 2418 MeV and a width of about 163 MeV or 225 MeV.
hep-ph/9412256
Martin Klein
Martin Klein-Kreisler and Manuel Torres
Parity Symmetry Restoration in Qed3 at High Temperature and Finite Density
Minor Latexing problem corrected
Phys.Lett. B347 (1995) 361-366
10.1016/0370-2693(95)00085-Y
Preprint IFUNAM, FT94-66 Dec/94
hep-ph cond-mat hep-th
null
We investigate the properties of quantum electrodynamics $(QED_3)$ in two spatial dimensions at finite temperature and density. The static as well as the dynamical properties of the planar plasma are calculated using the real time formalism of quantum field theory. It is shown, that due to the presence of the parity breaking Chern-Simons term, the propagating modes of the photon consists of two longielliptic waves with different values for the masses. However, it is shown that both in the high temperature and high density limit the parity symmetry is restored; in this limit the propagating modes reduce to the longitudinal and transverse ones, both with the same mass.
[ { "created": "Wed, 7 Dec 1994 23:36:21 GMT", "version": "v1" }, { "created": "Tue, 3 Jan 1995 22:22:53 GMT", "version": "v2" } ]
2009-10-28
[ [ "Klein-Kreisler", "Martin", "" ], [ "Torres", "Manuel", "" ] ]
We investigate the properties of quantum electrodynamics $(QED_3)$ in two spatial dimensions at finite temperature and density. The static as well as the dynamical properties of the planar plasma are calculated using the real time formalism of quantum field theory. It is shown, that due to the presence of the parity breaking Chern-Simons term, the propagating modes of the photon consists of two longielliptic waves with different values for the masses. However, it is shown that both in the high temperature and high density limit the parity symmetry is restored; in this limit the propagating modes reduce to the longitudinal and transverse ones, both with the same mass.
1412.4945
Konstantin Klimenko
K.G. Klimenko, R.N. Zhokhov
Zeeman interaction and chiral symmetry breaking by tilted magnetic field in the (2+1)-dimensional Gross--Neveu model
8 pages; Talk given by R.N. Zhokhov at the international conferences "Quarks-2014" (Suzdal, Russia, 2-8 June, 2014) and "New frontiers in physics" (Kolimbari, Crete, Greece, 29 July-6 Aug, 2014)
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Magnetic catalysis of the chiral symmetry breaking and other magnetic properties of the (2+1)-dimensional Gross--Neveu model are studied taking into account the Zeeman interaction of spin-1/2 quasi-particles (electrons) with tilted (with respect to a system plane) external magnetic field. The Zeeman interaction is proportional to magnetic moment $\mu_B$ of electrons. It is shown that at $\mu_B\ne 0$ the magnetic catalysis effect is drastically changed in comparison with the $\mu_B= 0$ case.
[ { "created": "Tue, 16 Dec 2014 10:40:09 GMT", "version": "v1" } ]
2014-12-17
[ [ "Klimenko", "K. G.", "" ], [ "Zhokhov", "R. N.", "" ] ]
Magnetic catalysis of the chiral symmetry breaking and other magnetic properties of the (2+1)-dimensional Gross--Neveu model are studied taking into account the Zeeman interaction of spin-1/2 quasi-particles (electrons) with tilted (with respect to a system plane) external magnetic field. The Zeeman interaction is proportional to magnetic moment $\mu_B$ of electrons. It is shown that at $\mu_B\ne 0$ the magnetic catalysis effect is drastically changed in comparison with the $\mu_B= 0$ case.
hep-ph/9809422
Nir Polonsky
Nir Polonsky
Supergravity Miracles: Phenomenology with Gravitational Divergences
5 pages. LaTex + sprocl.sty (included). Talk presented at PASCOS-98
null
null
RU-98-31
hep-ph
null
The properties of singlet fields in supergravity background are discussed. Particularly, it is shown that the ${\cal{O}}(\Lambda^{2})$ contributions to their one-point function lead to novel derivations of effective scales such as the $\mu$ parameter, a messenger scale, an intermediate symmetry-breaking scale, and the unification scale, in terms of the scale of spontaneous supersymmetry-breaking in a hidden sector.The singlet one-point function effectively serves as a messenger of supersymmetry breaking.
[ { "created": "Wed, 16 Sep 1998 21:25:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Polonsky", "Nir", "" ] ]
The properties of singlet fields in supergravity background are discussed. Particularly, it is shown that the ${\cal{O}}(\Lambda^{2})$ contributions to their one-point function lead to novel derivations of effective scales such as the $\mu$ parameter, a messenger scale, an intermediate symmetry-breaking scale, and the unification scale, in terms of the scale of spontaneous supersymmetry-breaking in a hidden sector.The singlet one-point function effectively serves as a messenger of supersymmetry breaking.