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2212.03561
Hai-Bing Fu
Zai-Hui Wu, Hai-Bing Fu, Tao Zhong, Yu Chen, Ya-Hong Dai
Searching for $a_0(980)$-meson parton distribution function
7 pages, 3 figures, comments welcome
null
10.1088/1572-9494/ace038
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we calculate the scalar $a_0(980)$-meson leading-twist wavefunction by using light-cone harmonic oscillator model (LCHO). In which the model parameters are determined by fitting the $\xi$-moments $\langle\xi_{a_0}^n\rangle_\zeta$ of its light-cone distribution amplitudes. Then, the $a_0(980)$-meson leading-twist light-cone distribution amplitudes with three different scales $\zeta= (1.0, 2.0, 5.2)~{\rm GeV}$ are given. After constructing the relationship between $a_0(980)$-meson leading-twist parton distribution functions/valence quark distribution function and its LCHO wavefunction, we exhibit the $q^{a_0}(x,\zeta)$ and $x q^{a_0}(x,\zeta)$ with different scales. Furthermore, we also calculate the Mellin moments of the $a_0(980)$-meson's valence quark distribution function $\langle x^n q^{a_0}\rangle_\zeta$ with $n = (1,2,3)$, i.e. $\langle x q^{a_0}\rangle_{\zeta_5} = 0.026$, $\langle x^2 q^{a_0}\rangle_{\zeta_5} = 0.017$ and $\langle x^3 q^{a_0}\rangle_{\zeta_5} = 0.012$. Finally, the scale evolution for the ratio of the Mellin moments $x^n_{a_0}(\zeta,\zeta_k)$ are presented.
[ { "created": "Wed, 7 Dec 2022 10:27:48 GMT", "version": "v1" } ]
2023-08-16
[ [ "Wu", "Zai-Hui", "" ], [ "Fu", "Hai-Bing", "" ], [ "Zhong", "Tao", "" ], [ "Chen", "Yu", "" ], [ "Dai", "Ya-Hong", "" ] ]
In this paper, we calculate the scalar $a_0(980)$-meson leading-twist wavefunction by using light-cone harmonic oscillator model (LCHO). In which the model parameters are determined by fitting the $\xi$-moments $\langle\xi_{a_0}^n\rangle_\zeta$ of its light-cone distribution amplitudes. Then, the $a_0(980)$-meson leading-twist light-cone distribution amplitudes with three different scales $\zeta= (1.0, 2.0, 5.2)~{\rm GeV}$ are given. After constructing the relationship between $a_0(980)$-meson leading-twist parton distribution functions/valence quark distribution function and its LCHO wavefunction, we exhibit the $q^{a_0}(x,\zeta)$ and $x q^{a_0}(x,\zeta)$ with different scales. Furthermore, we also calculate the Mellin moments of the $a_0(980)$-meson's valence quark distribution function $\langle x^n q^{a_0}\rangle_\zeta$ with $n = (1,2,3)$, i.e. $\langle x q^{a_0}\rangle_{\zeta_5} = 0.026$, $\langle x^2 q^{a_0}\rangle_{\zeta_5} = 0.017$ and $\langle x^3 q^{a_0}\rangle_{\zeta_5} = 0.012$. Finally, the scale evolution for the ratio of the Mellin moments $x^n_{a_0}(\zeta,\zeta_k)$ are presented.
1908.03227
Graham White Dr
Jeff A. Dror, Takashi Hiramatsu, Kazunori Kohri, Hitoshi Murayama and Graham White
Testing Seesaw and Leptogenesis with Gravitational Waves
6 pages, 1 figures, published version
Phys. Rev. Lett. 124, 041804 (2020)
10.1103/PhysRevLett.124.041804
IPMU19-0108, DESY 19-138, KEK-TH-2147, KEK-Cosmo-241
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the possibility that the seesaw mechanism with thermal leptogenesis can be tested using the stochastic gravitational background. Achieving neutrino masses consistent with atmospheric and solar neutrino data, while avoiding non-perturbative couplings, requires right-neutrinos lighter than the typical scale of grand unification. This scale separation suggests a symmetry protecting the right handed neutrinos from getting a mass. Thermal leptogenesis would then require that such a symmetry be broken below the reheating temperature. We enumerate all such possible symmetries consistent with these minimal assumptions and their corresponding defects, finding that in many cases, gravitational waves from the network of cosmic strings should be detectable. Estimating the predicted gravitational wave background we find that future space-borne missions could probe the entire range relevant for thermal leptogenesis.
[ { "created": "Thu, 8 Aug 2019 18:09:19 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 2020 15:48:26 GMT", "version": "v2" } ]
2020-03-11
[ [ "Dror", "Jeff A.", "" ], [ "Hiramatsu", "Takashi", "" ], [ "Kohri", "Kazunori", "" ], [ "Murayama", "Hitoshi", "" ], [ "White", "Graham", "" ] ]
We present the possibility that the seesaw mechanism with thermal leptogenesis can be tested using the stochastic gravitational background. Achieving neutrino masses consistent with atmospheric and solar neutrino data, while avoiding non-perturbative couplings, requires right-neutrinos lighter than the typical scale of grand unification. This scale separation suggests a symmetry protecting the right handed neutrinos from getting a mass. Thermal leptogenesis would then require that such a symmetry be broken below the reheating temperature. We enumerate all such possible symmetries consistent with these minimal assumptions and their corresponding defects, finding that in many cases, gravitational waves from the network of cosmic strings should be detectable. Estimating the predicted gravitational wave background we find that future space-borne missions could probe the entire range relevant for thermal leptogenesis.
hep-ph/9712334
Abdelhak Djouadi
Abdelhak Djouadi (LPM Montpellier)
Decays of the Higgs Bosons
26 pages, latex, 9 figures
null
null
PM-97/51
hep-ph
null
We review the decay modes of the Standard Model Higgs boson and those of the neutral and charged Higgs particles of the Minimal Supersymmetric extension of the Standard Model. Special emphasis will be put on higher-order effects. [Talk given at the International Workshop on Quantum Effects in the MSSM. Barcelona, Spain, September 9-13, 1997.]
[ { "created": "Wed, 10 Dec 1997 19:17:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Djouadi", "Abdelhak", "", "LPM Montpellier" ] ]
We review the decay modes of the Standard Model Higgs boson and those of the neutral and charged Higgs particles of the Minimal Supersymmetric extension of the Standard Model. Special emphasis will be put on higher-order effects. [Talk given at the International Workshop on Quantum Effects in the MSSM. Barcelona, Spain, September 9-13, 1997.]
hep-ph/0508192
Yu-Xin Liu
Lei Chang, Yu-xin Liu, and Hua Guo
Pion-nucleon Sigma Term in the Global Color Model of QCD
17 pages, 3 figures
Phys.Rev. D72 (2005) 094023
10.1103/PhysRevD.72.094023
null
hep-ph
null
We study the pion-nucleon sigma term in vacuum and in nuclear matter in the framework of global color model of QCD. With the effective gluon propagator being taken as the $\delta$-function in momentum space of Munczek-Nomirovsky model, we estimate that the sigma term at chiral limit in the vacuum is 9/2 times the current quark mass and it decreases with the nuclear matter density. With the presently obtained in-medium pion-nucleon sigma term, we study the in-medium chiral quark condensate and obtain a reasonable variation behavior against the nuclear matter density.
[ { "created": "Thu, 18 Aug 2005 09:40:29 GMT", "version": "v1" }, { "created": "Fri, 25 Nov 2005 01:23:03 GMT", "version": "v2" } ]
2009-11-11
[ [ "Chang", "Lei", "" ], [ "Liu", "Yu-xin", "" ], [ "Guo", "Hua", "" ] ]
We study the pion-nucleon sigma term in vacuum and in nuclear matter in the framework of global color model of QCD. With the effective gluon propagator being taken as the $\delta$-function in momentum space of Munczek-Nomirovsky model, we estimate that the sigma term at chiral limit in the vacuum is 9/2 times the current quark mass and it decreases with the nuclear matter density. With the presently obtained in-medium pion-nucleon sigma term, we study the in-medium chiral quark condensate and obtain a reasonable variation behavior against the nuclear matter density.
hep-ph/0101277
Elvio Disalvo
Elvio Di Salvo
Transverse Spin Asymmetries in Drell-Yan Processes: $\mathbf p^{\uparrow} p \to \mu^+ \mu^- X$}
null
Eur.Phys.J.C19:503-515,2001
10.1007/s100520100619
GEF-Th-2/00
hep-ph
null
We consider two different spin asymmetries in Drell-Yan processes generated by the collisions of an unpolarized proton beam on transversely polarized protons: the muon helicity asymmetry and the left-right asymmetry. We calculate the asymmetries in the framework of the QCD improved parton model, taking into account the parton transverse momentum and considering the first order QCD corrections. The muon helicity asymmetry is sensitive to the quark transversity distribution and is nonvanishing even at zero order. On the contrary the left-right asymmetry vanishes at zero order but not at first order in the QCD coupling constant, as a result of gluon contribution.
[ { "created": "Wed, 24 Jan 2001 17:23:47 GMT", "version": "v1" } ]
2009-01-07
[ [ "Di Salvo", "Elvio", "" ] ]
We consider two different spin asymmetries in Drell-Yan processes generated by the collisions of an unpolarized proton beam on transversely polarized protons: the muon helicity asymmetry and the left-right asymmetry. We calculate the asymmetries in the framework of the QCD improved parton model, taking into account the parton transverse momentum and considering the first order QCD corrections. The muon helicity asymmetry is sensitive to the quark transversity distribution and is nonvanishing even at zero order. On the contrary the left-right asymmetry vanishes at zero order but not at first order in the QCD coupling constant, as a result of gluon contribution.
1201.1768
Jialun Ping
Chengrong Deng, Jialun Ping, Fan Wang
QCD quark cyclobutadiene and light tetraquark spectrum
10 pages, 4 figures, Some statements are changed
null
10.1103/PhysRevD.86.114035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The QCD quark cyclobutadiene (ring-like), a new color structure of tetraquark system, is proposed and studied in the flux tube model with multi-body confinement potential. The QCD quark cyclobutadiene and other flux tube structures of tetraquark states have similar energies and they can be regarded as QCD isomeric compounds. The light tetraquark spectra ($u, d, s$ only) with ring-like and diquark-antidiquark structures are calculated in the flux tube model. The results show that many experimental states have the masses close to the calculated values if they are taken as tetraquark states. The isotensor states with $J^{PC}=1^{--}$ and $J^{PC}=2^{++}$ are studied and predicted that the masses are around 1500 MeV. The multi-body interaction plays a important role to reduce the energy of the multiquark state.
[ { "created": "Mon, 9 Jan 2012 14:13:01 GMT", "version": "v1" }, { "created": "Sun, 19 Feb 2012 16:30:00 GMT", "version": "v2" }, { "created": "Tue, 16 Oct 2012 16:51:51 GMT", "version": "v3" } ]
2015-06-03
[ [ "Deng", "Chengrong", "" ], [ "Ping", "Jialun", "" ], [ "Wang", "Fan", "" ] ]
The QCD quark cyclobutadiene (ring-like), a new color structure of tetraquark system, is proposed and studied in the flux tube model with multi-body confinement potential. The QCD quark cyclobutadiene and other flux tube structures of tetraquark states have similar energies and they can be regarded as QCD isomeric compounds. The light tetraquark spectra ($u, d, s$ only) with ring-like and diquark-antidiquark structures are calculated in the flux tube model. The results show that many experimental states have the masses close to the calculated values if they are taken as tetraquark states. The isotensor states with $J^{PC}=1^{--}$ and $J^{PC}=2^{++}$ are studied and predicted that the masses are around 1500 MeV. The multi-body interaction plays a important role to reduce the energy of the multiquark state.
hep-ph/0403213
Guohuai Zhu
T. N. Pham, Guohuai Zhu
Power Corrections in Charmless B Decays
references and note added, to appear in Phys. Rev. D
Phys.Rev. D69 (2004) 114016
10.1103/PhysRevD.69.114016
null
hep-ph hep-ex
null
In this paper, we focus on the role of power corrections in QCD factorization(QCDF) method in charmless two-body nonleptonic $B$ meson decays. We use the ratio of the branching fraction of $B^+ \to \pi^+ K^{\ast 0}$ to that of $B^0 \to \pi^- \rho^+$, for which the theoretical uncertainties are greatly reduced, to show clearly that the power corrections in charmless B decays are probably large. With other similar ratios considered, for example, for the $B^0 \to K^- \rho^+$ decay, it is very likely that, among various sources of power corrections, annihilation topology plays an indispensable role at least for penguin dominated $\rm PV$ channels. We also consider some selective ratios of direct CP asymmetries. Among these, we find that, if power corrections other than the chirally enhanced power corrections and annihilation topology were negligible, QCDF would predict the direct CP asymmetry of $B \to \pi^+ \pi^-$ to be about 3 times larger than that of $B \to \pi^\pm K^\mp$, with opposite sign. Experimentally any significant deviation from this prediction would suggest either new physics or possibly the importance of long-distance rescattering effects.
[ { "created": "Fri, 19 Mar 2004 13:58:28 GMT", "version": "v1" }, { "created": "Mon, 19 Apr 2004 12:56:26 GMT", "version": "v2" } ]
2009-11-10
[ [ "Pham", "T. N.", "" ], [ "Zhu", "Guohuai", "" ] ]
In this paper, we focus on the role of power corrections in QCD factorization(QCDF) method in charmless two-body nonleptonic $B$ meson decays. We use the ratio of the branching fraction of $B^+ \to \pi^+ K^{\ast 0}$ to that of $B^0 \to \pi^- \rho^+$, for which the theoretical uncertainties are greatly reduced, to show clearly that the power corrections in charmless B decays are probably large. With other similar ratios considered, for example, for the $B^0 \to K^- \rho^+$ decay, it is very likely that, among various sources of power corrections, annihilation topology plays an indispensable role at least for penguin dominated $\rm PV$ channels. We also consider some selective ratios of direct CP asymmetries. Among these, we find that, if power corrections other than the chirally enhanced power corrections and annihilation topology were negligible, QCDF would predict the direct CP asymmetry of $B \to \pi^+ \pi^-$ to be about 3 times larger than that of $B \to \pi^\pm K^\mp$, with opposite sign. Experimentally any significant deviation from this prediction would suggest either new physics or possibly the importance of long-distance rescattering effects.
0807.0098
Yoshitaka Hatta
Yoshitaka Hatta and Toshihiro Matsuo
Thermal hadron spectrum in $e^+e^-$ annihilation from gauge/string duality
4 pages, revtex4; v2. discussion slightly expanded
Phys.Rev.Lett.102:062001,2009
10.1103/PhysRevLett.102.062001
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the inclusive spectrum of produced particles in e+e- annihilation in confining gauge theories that have a gravity dual and show that the momentum distribution exhibits the thermal behavior.
[ { "created": "Tue, 1 Jul 2008 10:03:53 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2008 12:39:48 GMT", "version": "v2" } ]
2009-02-27
[ [ "Hatta", "Yoshitaka", "" ], [ "Matsuo", "Toshihiro", "" ] ]
We compute the inclusive spectrum of produced particles in e+e- annihilation in confining gauge theories that have a gravity dual and show that the momentum distribution exhibits the thermal behavior.
hep-ph/9502417
null
David H. Lyth and Ewan D. Stewart
Cosmology with a TeV mass GUT Higgs
4 pages, revtex
Phys.Rev.Lett. 75 (1995) 201-204
10.1103/PhysRevLett.75.201
LANCASTER-TH/9502
hep-ph astro-ph gr-qc hep-th
null
The most natural way to break the GUT gauge symmetry is with a Higgs field whose vacuum expectation value is of order $10^{16}\,\mbox{GeV}$ but whose mass is of order $10^2$ to $10^3\,\mbox{GeV}$. This can lead to a cosmological history radically different from what is usually assumed to have occurred between the standard inflationary and nucleosynthesis epochs, which may solve the gravitino and Polonyi/moduli problems in a natural way.
[ { "created": "Tue, 28 Feb 1995 21:13:26 GMT", "version": "v1" } ]
2016-09-01
[ [ "Lyth", "David H.", "" ], [ "Stewart", "Ewan D.", "" ] ]
The most natural way to break the GUT gauge symmetry is with a Higgs field whose vacuum expectation value is of order $10^{16}\,\mbox{GeV}$ but whose mass is of order $10^2$ to $10^3\,\mbox{GeV}$. This can lead to a cosmological history radically different from what is usually assumed to have occurred between the standard inflationary and nucleosynthesis epochs, which may solve the gravitino and Polonyi/moduli problems in a natural way.
2005.07200
Peter Denton
Asli Abdullahi and Peter B. Denton
Visible Decay of Astrophysical Neutrinos at IceCube
18 pages, 9 figures, comments welcome! Code available at https://github.com/PeterDenton/Astro-Nu-Decay; v2: clarifying remarks and references add, matches published version
Phys. Rev. D 102, 023018 (2020)
10.1103/PhysRevD.102.023018
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino decay modifies neutrino propagation in a unique way; not only is there flavor changing as there is in neutrino oscillations, there is also energy transport from initial to final neutrinos. The most sensitive direct probe of neutrino decay is currently IceCube which can measure the energy and flavor of neutrinos traveling over extragalactic distances. For the first time we calculate the flavor transition probability for the cases of visible and invisible neutrino decay, including the effects of the expansion of the universe, and consider the implications for IceCube. As an example, we demonstrate how neutrino decay addresses a tension in the IceCube data. We also provide a publicly available code to calculate the effect of visible decay.
[ { "created": "Thu, 14 May 2020 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 14 Jul 2020 15:12:15 GMT", "version": "v2" } ]
2020-07-15
[ [ "Abdullahi", "Asli", "" ], [ "Denton", "Peter B.", "" ] ]
Neutrino decay modifies neutrino propagation in a unique way; not only is there flavor changing as there is in neutrino oscillations, there is also energy transport from initial to final neutrinos. The most sensitive direct probe of neutrino decay is currently IceCube which can measure the energy and flavor of neutrinos traveling over extragalactic distances. For the first time we calculate the flavor transition probability for the cases of visible and invisible neutrino decay, including the effects of the expansion of the universe, and consider the implications for IceCube. As an example, we demonstrate how neutrino decay addresses a tension in the IceCube data. We also provide a publicly available code to calculate the effect of visible decay.
hep-ph/9709384
Leonid Satarov
I.N. Mishustin, L.M. Satarov, H. Stoecker, W. Greiner
Dilepton production by bremsstrahlung of meson fields in nuclear collisions
14 pages
Phys.Rev.C57:2552-2558,1998
10.1103/PhysRevC.57.2552
null
hep-ph
null
We study the bremsstrahlung of virtual omega mesons due to the collective deceleration of nuclei at the initial stage of an ultrarelativistic heavy-ion collision. It is shown that electromagnetic decays of these mesons may give an important contribution to the observed yields of dileptons. Mass spectra of positron-electron and muon pairs produced in central Au+Au collisions are calculated under some simplifying assumptions on the space-time variation of the baryonic current in a nuclear collision process. Comparison with the CERES data for 160 AGev Pb+Au collisions shows that the proposed mechanism gives a noticeable fraction of the observed lepton pairs in the intermediate region of invariant masses. Sensitivity of the dilepton yield to the in-medium modification of masses and widths of vector mesons is demonstrated.
[ { "created": "Wed, 17 Sep 1997 20:30:04 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mishustin", "I. N.", "" ], [ "Satarov", "L. M.", "" ], [ "Stoecker", "H.", "" ], [ "Greiner", "W.", "" ] ]
We study the bremsstrahlung of virtual omega mesons due to the collective deceleration of nuclei at the initial stage of an ultrarelativistic heavy-ion collision. It is shown that electromagnetic decays of these mesons may give an important contribution to the observed yields of dileptons. Mass spectra of positron-electron and muon pairs produced in central Au+Au collisions are calculated under some simplifying assumptions on the space-time variation of the baryonic current in a nuclear collision process. Comparison with the CERES data for 160 AGev Pb+Au collisions shows that the proposed mechanism gives a noticeable fraction of the observed lepton pairs in the intermediate region of invariant masses. Sensitivity of the dilepton yield to the in-medium modification of masses and widths of vector mesons is demonstrated.
1709.09961
Amir N. Khan
Amir N. Khan, Douglas W. McKay
Probing New Physics in Low Energy Solar Neutrino Oscillation Data
2 figure, Conference Proceedings (6th CST-MISC Joint Symposium on Particle Physics -- from Space-time Dynamics to Phenomenology --, Oct. 15-16, 2016, Campus Plaza Kyoto, Kyoto, Japan.)
http://www2.yukawa.kyoto-u.ac.jp/~soken.editorial/sokendenshi/vol26/proceedings2016.pdf
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the effects of nonstandard neutrino interactions in the lower components of the solar neutrino spectrum which are predominant by the vacuum oscillations. The recent measurements of Borexino experiment between 2011 and 2015 provide a clean test to study the nonstandard neutrino interactions at the source (sun) and the at solar detector. In this work, first the possible standard model parameters are estimated from the combined data of the low energy regime and then the nonstandard effects at the source, at the detector, and from the interplay between source and detector parameters are bounded. The same effects are also investigated for the proposed experiments like LENA and Jinpin Neutrino Experiment with their projected sensitivities.
[ { "created": "Thu, 28 Sep 2017 13:49:23 GMT", "version": "v1" } ]
2017-09-29
[ [ "Khan", "Amir N.", "" ], [ "McKay", "Douglas W.", "" ] ]
We explore the effects of nonstandard neutrino interactions in the lower components of the solar neutrino spectrum which are predominant by the vacuum oscillations. The recent measurements of Borexino experiment between 2011 and 2015 provide a clean test to study the nonstandard neutrino interactions at the source (sun) and the at solar detector. In this work, first the possible standard model parameters are estimated from the combined data of the low energy regime and then the nonstandard effects at the source, at the detector, and from the interplay between source and detector parameters are bounded. The same effects are also investigated for the proposed experiments like LENA and Jinpin Neutrino Experiment with their projected sensitivities.
0705.1975
Sven-Olaf Moch
M. Czakon, A. Mitov and S. Moch
Heavy-quark production in massless quark scattering at two loops in QCD
17 pages latex, 2 figures
Phys.Lett.B651:147-159,2007
10.1016/j.physletb.2007.06.020
DESY 07-064, SFB/CPP-07-19
hep-ph
null
We present the two-loop virtual QCD corrections to the production of heavy quarks in the quark--anti-quark--annihilation channel in the limit when all kinematical invariants are large compared to the mass of the heavy quark. Our result is exact up to terms suppressed by powers of the heavy-quark mass. The derivation is based on a simple relation between massless and massive scattering amplitudes in gauge theories proposed recently by two of the authors as well as a direct calculation of the massive amplitude at two loops. The results presented here form an important part of the next-to-next-to-leading order QCD contributions to heavy-quark production in hadron-hadron collisions.
[ { "created": "Mon, 14 May 2007 16:21:14 GMT", "version": "v1" } ]
2008-11-26
[ [ "Czakon", "M.", "" ], [ "Mitov", "A.", "" ], [ "Moch", "S.", "" ] ]
We present the two-loop virtual QCD corrections to the production of heavy quarks in the quark--anti-quark--annihilation channel in the limit when all kinematical invariants are large compared to the mass of the heavy quark. Our result is exact up to terms suppressed by powers of the heavy-quark mass. The derivation is based on a simple relation between massless and massive scattering amplitudes in gauge theories proposed recently by two of the authors as well as a direct calculation of the massive amplitude at two loops. The results presented here form an important part of the next-to-next-to-leading order QCD contributions to heavy-quark production in hadron-hadron collisions.
1412.7603
Hiroshi Yokoya
Shinya Kanemura, Mariko Kikuchi, Kei Yagyu, Hiroshi Yokoya
LHC Run-I constraint on the mass of doubly charged Higgs bosons in the same-sign diboson decay scenario
4 pages, 1 figures; minor modifications
null
10.1093/ptep/ptv071
UT-HET-098
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this Letter, we study the latest bound on the mass of doubly charged Higgs bosons, $H^{\pm\pm}$, assuming that they dominantly decay into a diboson. The new bound is obtained by comparing the inclusive searches for events with a same-sign dilepton by the ATLAS Collaboration using the latest 20.3 fb$^{-1}$ data at the LHC 8 TeV run with theoretical prediction based on the Higgs triplet model with next-to-leading order QCD corrections. We find that the lower mass bound on $H^{\pm\pm}$ is about 84 GeV.
[ { "created": "Wed, 24 Dec 2014 05:01:24 GMT", "version": "v1" }, { "created": "Fri, 6 Mar 2015 17:02:46 GMT", "version": "v2" } ]
2015-05-27
[ [ "Kanemura", "Shinya", "" ], [ "Kikuchi", "Mariko", "" ], [ "Yagyu", "Kei", "" ], [ "Yokoya", "Hiroshi", "" ] ]
In this Letter, we study the latest bound on the mass of doubly charged Higgs bosons, $H^{\pm\pm}$, assuming that they dominantly decay into a diboson. The new bound is obtained by comparing the inclusive searches for events with a same-sign dilepton by the ATLAS Collaboration using the latest 20.3 fb$^{-1}$ data at the LHC 8 TeV run with theoretical prediction based on the Higgs triplet model with next-to-leading order QCD corrections. We find that the lower mass bound on $H^{\pm\pm}$ is about 84 GeV.
2210.10022
Masaki Yamada
Shota Nakagawa, Fuminobu Takahashi, Masaki Yamada, Wen Yin
Axion dark matter from first-order phase transition, and very high energy photons from GRB 221009A
7 pages, 1 figure
null
10.1016/j.physletb.2023.137824
TU-1172
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an axion-like particle (ALP) that experiences the first-order phase transition with respect to its mass or potential minimum. This can be realized if the ALP obtains a potential from non-perturbative effects of SU($N$) gauge theory that is confined via the first-order phase transition, or if the ALP is trapped in a false vacuum at high temperatures until it starts to oscillate about the true minimum. The resulting ALP abundance is significantly enhanced compared to the standard misalignment mechanism, explaining dark matter in a broader parameter space that is accessible to experiments e.g. IAXO, ALPS-II, and DM-radio. Furthermore, the viable parameter space includes a region of the mass $m_a \simeq 10^{-7} - 10^{-8}$ eV and the ALP-photon coupling $g_{a \gamma \gamma} \simeq 10^{-11} {\rm GeV}^{-1}$ that can explain the recent observation of very high energy photons from GRB221009A via axion-photon oscillations. The parameter region suggests that the FOPT can generate the gravitational wave that explains the NANOGrav hint. If the ALP in this region explains dark matter, then the ALP has likely experienced a first-order phase transition.
[ { "created": "Tue, 18 Oct 2022 17:46:20 GMT", "version": "v1" }, { "created": "Mon, 31 Oct 2022 04:49:19 GMT", "version": "v2" } ]
2023-04-05
[ [ "Nakagawa", "Shota", "" ], [ "Takahashi", "Fuminobu", "" ], [ "Yamada", "Masaki", "" ], [ "Yin", "Wen", "" ] ]
We study an axion-like particle (ALP) that experiences the first-order phase transition with respect to its mass or potential minimum. This can be realized if the ALP obtains a potential from non-perturbative effects of SU($N$) gauge theory that is confined via the first-order phase transition, or if the ALP is trapped in a false vacuum at high temperatures until it starts to oscillate about the true minimum. The resulting ALP abundance is significantly enhanced compared to the standard misalignment mechanism, explaining dark matter in a broader parameter space that is accessible to experiments e.g. IAXO, ALPS-II, and DM-radio. Furthermore, the viable parameter space includes a region of the mass $m_a \simeq 10^{-7} - 10^{-8}$ eV and the ALP-photon coupling $g_{a \gamma \gamma} \simeq 10^{-11} {\rm GeV}^{-1}$ that can explain the recent observation of very high energy photons from GRB221009A via axion-photon oscillations. The parameter region suggests that the FOPT can generate the gravitational wave that explains the NANOGrav hint. If the ALP in this region explains dark matter, then the ALP has likely experienced a first-order phase transition.
hep-ph/0003214
Shailesh Chandrasekharan
Shailesh Chandrasekharan (Duke University) and Uwe-Jens Wiese (MIT)
SO(10) Unification of Color Superconductivity and Chiral Symmetry Breaking?
4 pages, 2 figures, RevTex
null
null
DUKE-TH-00-203, MIT-CTP-2961
hep-ph cond-mat.supr-con hep-lat
null
Motivated by the SO(5) theory of high-temperature superconductivity and antiferromagnetism, we ask if an SO(10) theory unifies color superconductivity and chiral symmetry breaking in QCD. The transition to the color superconducting phase would then be analogous to a spin flop transition. While the spin flop transition generically has a unified SO(3) description, the SO(5) and SO(10) symmetric fixed points are unstable, at least in (4 - epsilon) dimensions, and require the fine-tuning of one additional relevant parameter. If QCD is near the SO(10) fixed point, it has interesting consequences for heavy ion collisions and neutron stars.
[ { "created": "Wed, 22 Mar 2000 02:28:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Chandrasekharan", "Shailesh", "", "Duke University" ], [ "Wiese", "Uwe-Jens", "", "MIT" ] ]
Motivated by the SO(5) theory of high-temperature superconductivity and antiferromagnetism, we ask if an SO(10) theory unifies color superconductivity and chiral symmetry breaking in QCD. The transition to the color superconducting phase would then be analogous to a spin flop transition. While the spin flop transition generically has a unified SO(3) description, the SO(5) and SO(10) symmetric fixed points are unstable, at least in (4 - epsilon) dimensions, and require the fine-tuning of one additional relevant parameter. If QCD is near the SO(10) fixed point, it has interesting consequences for heavy ion collisions and neutron stars.
2309.02127
Silvia Ferrario Ravasio
Andrea Banfi, Silvia Ferrario Ravasio, Barbara J\"ager, Alexander Karlberg, Felix Reichenbach, and Giulia Zanderighi
A POWHEG generator for deep inelastic scattering
54 pages, 25 figures, code obtainable from svn://powhegbox.mib.infn.it/trunk/User-Processes-RES/DIS
JHEP02(2024)001
https://doi.org/10.1007/JHEP02(2024)023
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We present a new event generator for the simulation of both neutral- and charged-current deep inelastic scattering (DIS) at next-to-leading order in QCD matched to parton showers using the POWHEG method. Our implementation builds on the existing POWHEG BOX framework originally designed for hadron-hadron collisions, supplemented by considerable extensions to account for the genuinely different kinematics inherent to lepton-hadron collisions. In particular, we present new momentum mappings that conserve the special kinematics found in DIS, which we use to modify the POWHEG BOX implementation of the Frixione-Kunszt-Signer subtraction mechanism. We compare our predictions to fixed-order and resummed predictions, as well as to data from the HERA ep collider. Finally we study a few representative distributions for the upcoming Electron Ion Collider.
[ { "created": "Tue, 5 Sep 2023 11:08:01 GMT", "version": "v1" }, { "created": "Mon, 5 Feb 2024 18:05:15 GMT", "version": "v2" } ]
2024-02-09
[ [ "Banfi", "Andrea", "" ], [ "Ravasio", "Silvia Ferrario", "" ], [ "Jäger", "Barbara", "" ], [ "Karlberg", "Alexander", "" ], [ "Reichenbach", "Felix", "" ], [ "Zanderighi", "Giulia", "" ] ]
We present a new event generator for the simulation of both neutral- and charged-current deep inelastic scattering (DIS) at next-to-leading order in QCD matched to parton showers using the POWHEG method. Our implementation builds on the existing POWHEG BOX framework originally designed for hadron-hadron collisions, supplemented by considerable extensions to account for the genuinely different kinematics inherent to lepton-hadron collisions. In particular, we present new momentum mappings that conserve the special kinematics found in DIS, which we use to modify the POWHEG BOX implementation of the Frixione-Kunszt-Signer subtraction mechanism. We compare our predictions to fixed-order and resummed predictions, as well as to data from the HERA ep collider. Finally we study a few representative distributions for the upcoming Electron Ion Collider.
1907.12450
Felix Driencourt-Mangin
Felix Driencourt-Mangin
Four-dimensional representation of scattering amplitudes and physical observables through the application of the Loop-Tree Duality theorem
PhD. thesis, 181 pages
null
null
null
hep-ph hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this thesis we propose a novel method to compute higher-order corrections to physical cross sections, bypassing more traditional approaches. This technique, the Four-Dimensional Unsubtraction (FDU), is based on the Loop-Tree Duality (LTD) theorem, and aims at building pure four-dimensional representations of scattering amplitudes at higher orders in perturbation theory. This is done by locally renormalising the virtual contribution at high energies, and then mapping the kinematics of the corresponding real contribution so it matches the virtual one in the soft and collinear limits. This makes the ultraviolet and infrared singularities vanish at the integrand level when taking the sum of both contributions, meaning that the four-dimensional limit can be taken before integrating, thus allowing for a straightforward numerical implementation. We apply this method for the first time to calculate the decay of a virtual photon to two massless quarks, and then generalise the method to massive particles. We also show new advantages provided by the LTD formalism. One of them is the possibility to write one- and two-loop scattering amplitudes in a universal form at the integrand level, regardless of the nature of the particle running inside the loop. The other is to perform integrand-level asymptotic expansions in the internal mass - without having to rely on expansion-by-region techniques - by taking advantage of the Euclidean nature of the integration domain. Finally, we present a new algorithm to locally renormalise two-loop amplitudes, where the renormalisation scheme can be easily fixed through subleading contributions in the ultraviolet region.
[ { "created": "Mon, 29 Jul 2019 14:12:57 GMT", "version": "v1" } ]
2019-07-30
[ [ "Driencourt-Mangin", "Felix", "" ] ]
In this thesis we propose a novel method to compute higher-order corrections to physical cross sections, bypassing more traditional approaches. This technique, the Four-Dimensional Unsubtraction (FDU), is based on the Loop-Tree Duality (LTD) theorem, and aims at building pure four-dimensional representations of scattering amplitudes at higher orders in perturbation theory. This is done by locally renormalising the virtual contribution at high energies, and then mapping the kinematics of the corresponding real contribution so it matches the virtual one in the soft and collinear limits. This makes the ultraviolet and infrared singularities vanish at the integrand level when taking the sum of both contributions, meaning that the four-dimensional limit can be taken before integrating, thus allowing for a straightforward numerical implementation. We apply this method for the first time to calculate the decay of a virtual photon to two massless quarks, and then generalise the method to massive particles. We also show new advantages provided by the LTD formalism. One of them is the possibility to write one- and two-loop scattering amplitudes in a universal form at the integrand level, regardless of the nature of the particle running inside the loop. The other is to perform integrand-level asymptotic expansions in the internal mass - without having to rely on expansion-by-region techniques - by taking advantage of the Euclidean nature of the integration domain. Finally, we present a new algorithm to locally renormalise two-loop amplitudes, where the renormalisation scheme can be easily fixed through subleading contributions in the ultraviolet region.
hep-ph/9910301
Aurelio Juste
Aurelio Juste and Gonzalo Merino
Top-Higgs Yukawa Coupling Measurement at a Linear e+e- Collider
LaTex, 27 pages, 14 Postscript figures
null
null
null
hep-ph
null
A feasibility study of the measurement of the top-Higgs Yukawa coupling at a future linear e+e- collider operating at sqrt(s)=800 GeV is presented. As compared to previous existing studies, much effort has been put in a ``realistic simulation'' by including irreducible+reducible backgrounds, realistic detector effects and reconstruction procedures and finally, a multivariate analysis. Both hadronic and semileptonic decay channels have been considered.
[ { "created": "Tue, 12 Oct 1999 00:58:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Juste", "Aurelio", "" ], [ "Merino", "Gonzalo", "" ] ]
A feasibility study of the measurement of the top-Higgs Yukawa coupling at a future linear e+e- collider operating at sqrt(s)=800 GeV is presented. As compared to previous existing studies, much effort has been put in a ``realistic simulation'' by including irreducible+reducible backgrounds, realistic detector effects and reconstruction procedures and finally, a multivariate analysis. Both hadronic and semileptonic decay channels have been considered.
1512.06782
Mansi Dhuria
Mansi Dhuria, Gaurav Goswami
Perturbativity, vacuum stability and inflation in the light of 750 GeV diphoton excess
16 pages, 6 figures. Journal version (to appear in Phy. Rev. D)
Phys.Rev. D94 (2016) no.5, 055009
10.1103/PhysRevD.94.055009
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent observation of the 750 GeV diphoton excess at 13 TeV LHC has motivated many scenarios of physics beyond the Standard Model. In this work, we begin by showing that many models which explain the observed excess tend to get strongly coupled well below the Planck scale. We then study a simple scenario involving colored vector-like fermions with exotic charges, which is expected to stay weakly coupled till the Planck scale. We find the conditions under which this happens, derive the Renormalization Group equations for such models and solve them to show that perturbativity till Planck scale can be maintained for a very reasonable choice of parameters. Finally, we discuss issues related to vacuum stability and the possibility of inflation in the scenarios we study.
[ { "created": "Mon, 21 Dec 2015 19:48:51 GMT", "version": "v1" }, { "created": "Sun, 27 Dec 2015 19:03:52 GMT", "version": "v2" }, { "created": "Wed, 30 Dec 2015 19:51:25 GMT", "version": "v3" }, { "created": "Tue, 5 Jan 2016 18:10:55 GMT", "version": "v4" }, { "created": "Thu, 21 Jul 2016 19:49:18 GMT", "version": "v5" } ]
2016-12-02
[ [ "Dhuria", "Mansi", "" ], [ "Goswami", "Gaurav", "" ] ]
The recent observation of the 750 GeV diphoton excess at 13 TeV LHC has motivated many scenarios of physics beyond the Standard Model. In this work, we begin by showing that many models which explain the observed excess tend to get strongly coupled well below the Planck scale. We then study a simple scenario involving colored vector-like fermions with exotic charges, which is expected to stay weakly coupled till the Planck scale. We find the conditions under which this happens, derive the Renormalization Group equations for such models and solve them to show that perturbativity till Planck scale can be maintained for a very reasonable choice of parameters. Finally, we discuss issues related to vacuum stability and the possibility of inflation in the scenarios we study.
hep-ph/0007269
Anupam Mazumdar
Anupam Mazumdar
Interesting consequences of brane cosmology
5 pages, Trivial changes to match the published version
Phys.Rev. D64 (2001) 027304
10.1103/PhysRevD.64.027304
null
hep-ph astro-ph gr-qc hep-th
null
We discuss cosmology in four dimensions within a context of brane-world scenario.Such models can predict chaotic inflation with very low reheat temperature depending on the brane tension. We notice that the gravitino abundance is different in the brane-world cosmology and by tuning the brane tension it is possible to get extremely low abundance. We also study Affleck-Dine baryogenesis in our toy model.
[ { "created": "Mon, 24 Jul 2000 19:29:57 GMT", "version": "v1" }, { "created": "Mon, 24 Jul 2000 23:09:55 GMT", "version": "v2" }, { "created": "Mon, 9 Apr 2001 12:07:09 GMT", "version": "v3" } ]
2009-10-31
[ [ "Mazumdar", "Anupam", "" ] ]
We discuss cosmology in four dimensions within a context of brane-world scenario.Such models can predict chaotic inflation with very low reheat temperature depending on the brane tension. We notice that the gravitino abundance is different in the brane-world cosmology and by tuning the brane tension it is possible to get extremely low abundance. We also study Affleck-Dine baryogenesis in our toy model.
2406.00613
Hao-Song You
Hao-Song You, Hao Sun, Hong-Bo Li, Cheng-Jun Xia and Ren-Xin Xu
Compact dwarfs made of light-quark nuggets
null
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Utilizing an equivparticle model with both linear confinement and leading-order perturbative interactions, we obtain systematically the properties of strangelets and nonstrange quark matter ($ud$QM) nuggets at various baryon ($A$) and charge ($Z$) numbers, where the detailed single-quark-energy levels are fixed by solving Dirac equations in mean-field approximation (MFA). We then examine the structures of compact dwarfs made of light strangelets or $ud$QM nuggets forming body-centered cubic lattices in a uniform electron background. Despite the strangelets and $ud$QM nuggets generally become more stable at larger $A$, the compact dwarfs are still stable since the fusion reactions between those objects do not take place in the presence of a Coulomb barrier, which is similar to the cases of light nuclei in normal white dwarfs. If $ud$QM dwarfs or strangelet dwarfs are covered with normal matter, their masses and radii become larger but do not exceed those of ordinary white dwarfs. Finally, we investigate the radial oscillation frequencies of $ud$QM dwarfs and strangelet dwarfs, and find that their frequencies are typically higher than traditional white dwarfs. The stability of compact dwarfs are then analysised by examining radial oscillation frequencies of the fundamental mode, where compact dwarfs covered by normal matter are still stable.
[ { "created": "Sun, 2 Jun 2024 04:05:42 GMT", "version": "v1" } ]
2024-06-04
[ [ "You", "Hao-Song", "" ], [ "Sun", "Hao", "" ], [ "Li", "Hong-Bo", "" ], [ "Xia", "Cheng-Jun", "" ], [ "Xu", "Ren-Xin", "" ] ]
Utilizing an equivparticle model with both linear confinement and leading-order perturbative interactions, we obtain systematically the properties of strangelets and nonstrange quark matter ($ud$QM) nuggets at various baryon ($A$) and charge ($Z$) numbers, where the detailed single-quark-energy levels are fixed by solving Dirac equations in mean-field approximation (MFA). We then examine the structures of compact dwarfs made of light strangelets or $ud$QM nuggets forming body-centered cubic lattices in a uniform electron background. Despite the strangelets and $ud$QM nuggets generally become more stable at larger $A$, the compact dwarfs are still stable since the fusion reactions between those objects do not take place in the presence of a Coulomb barrier, which is similar to the cases of light nuclei in normal white dwarfs. If $ud$QM dwarfs or strangelet dwarfs are covered with normal matter, their masses and radii become larger but do not exceed those of ordinary white dwarfs. Finally, we investigate the radial oscillation frequencies of $ud$QM dwarfs and strangelet dwarfs, and find that their frequencies are typically higher than traditional white dwarfs. The stability of compact dwarfs are then analysised by examining radial oscillation frequencies of the fundamental mode, where compact dwarfs covered by normal matter are still stable.
1909.10511
Mikhail Sergeenko
Mikhail N. Sergeenko
Light and Heavy Mesons in The Complex Mass Scheme
12 pages, 2 tables, Presented at NONLINEAR PHENOMENA IN COMPLEX SYSTEMS, XXVI International Seminar, Chaos, Fractals, Phase Transitions, Self-organization,May 21--24, 2019, Minsk, Belarus. arXiv admin note: text overlap with arXiv:1712.02641, arXiv:1703.07766
null
null
MAXLA-2/19, "Meson''
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mesons containing light and heavy quarks are studied. Interaction of quarks is described by the funnel-type potential with the distant dependent strong coupling, $\alpha_\S(r)$. Free particle hypothesis for the bound state is developed: quark and antiquark move as free particles in of the bound system. Relativistic two-body wave equation with position dependent particle masses is used to describe the flavored $Qq$ systems. Solution of the equation for the system in the form of a~standing wave is given. Interpolating complex-mass formula for two exact asymptotic eigenmass expressions is obtained. Mass spectra for some leading-state flavored mesons are calculated.
[ { "created": "Sat, 21 Sep 2019 11:40:55 GMT", "version": "v1" } ]
2019-09-25
[ [ "Sergeenko", "Mikhail N.", "" ] ]
Mesons containing light and heavy quarks are studied. Interaction of quarks is described by the funnel-type potential with the distant dependent strong coupling, $\alpha_\S(r)$. Free particle hypothesis for the bound state is developed: quark and antiquark move as free particles in of the bound system. Relativistic two-body wave equation with position dependent particle masses is used to describe the flavored $Qq$ systems. Solution of the equation for the system in the form of a~standing wave is given. Interpolating complex-mass formula for two exact asymptotic eigenmass expressions is obtained. Mass spectra for some leading-state flavored mesons are calculated.
1603.02376
Yuki Shimizu
Yuki Shimizu, Daiki Suenaga, Masayasu Harada
Coupled channel analysis of molecule picture of $P_{c}(4380)$
7 pages, 9 figures
Phys. Rev. D 93, 114003 (2016)
10.1103/PhysRevD.93.114003
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a potential obtained by one-pion exchange for the coupled channel $\Sigma_c^\ast$$\bar{D}$-$\Sigma_c$$\bar{D}^\ast$, and solve the coupled Schr\"{o}dinger equations to determine the binding energy. We find that there exists one or two bound states with the binding energy of several MeV below the threshold of $\Sigma_c^\ast$ and $\bar{D}$, dominantly made from a $\Sigma_c^\ast$ baryon and a $\bar{D}$ meson, with the size of about $1.5$fm for wide parameter region. We also study the pentaquark states including a $b$ quark and/or an anti-$b$ quark. We show that there exist pentaquarks including $c\bar{b}$, $b\bar{c}$ and $b\bar{b}$, all of which lie at about $10$MeV below the corresponding threshold and have size of about $1.5$fm.
[ { "created": "Tue, 8 Mar 2016 04:22:30 GMT", "version": "v1" }, { "created": "Fri, 10 Jun 2016 08:51:08 GMT", "version": "v2" } ]
2016-06-15
[ [ "Shimizu", "Yuki", "" ], [ "Suenaga", "Daiki", "" ], [ "Harada", "Masayasu", "" ] ]
We construct a potential obtained by one-pion exchange for the coupled channel $\Sigma_c^\ast$$\bar{D}$-$\Sigma_c$$\bar{D}^\ast$, and solve the coupled Schr\"{o}dinger equations to determine the binding energy. We find that there exists one or two bound states with the binding energy of several MeV below the threshold of $\Sigma_c^\ast$ and $\bar{D}$, dominantly made from a $\Sigma_c^\ast$ baryon and a $\bar{D}$ meson, with the size of about $1.5$fm for wide parameter region. We also study the pentaquark states including a $b$ quark and/or an anti-$b$ quark. We show that there exist pentaquarks including $c\bar{b}$, $b\bar{c}$ and $b\bar{b}$, all of which lie at about $10$MeV below the corresponding threshold and have size of about $1.5$fm.
1504.05403
Alfredo Urbano
Marco Fabbrichesi, Alfredo Urbano
Naturalness redux
13 pages, 5 figures. Minor changes; version accepted for publication in PRD
Phys. Rev. D 92, 015028 (2015)
10.1103/PhysRevD.92.015028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The idea of naturalness, as originally conceived, refers only to the finite renormalization of the Higgs boson mass induced by the introduction of heavier states. In this respect, naturalness is still a powerful heuristic principle in model building beyond the standard model whenever new massive states are coupled to the Higgs field. The most compelling case is provided by the generation of neutrino masses. In this paper we confront this problem from a new perspective. The right-handed sector responsible for the seesaw mechanism---which introduces a large energy threshold above the electroweak scale---is made supersymmetric to comply with naturalness while the standard model is left unchanged and non-supersymmetric. Cancellations necessary to the naturalness requirement break down only at two loops, thus offering the possibility to increase the right-handed neutrino mass scale up to one order of magnitude above the usual values allowed by naturalness. If also the weak boson sector of the standard model is made supersymmetric, cancellations break down at three loops and the scale of new physics can be further raised. In the type-I seesaw, this implementation provides right-handed neutrino masses that are natural and at the same time large enough to give rise to baryogenesis (via leptogenesis). The model contains a dark matter candidate and distinctive new physics in the leptonic sector.
[ { "created": "Tue, 21 Apr 2015 12:28:03 GMT", "version": "v1" }, { "created": "Mon, 13 Jul 2015 19:31:59 GMT", "version": "v2" } ]
2015-08-05
[ [ "Fabbrichesi", "Marco", "" ], [ "Urbano", "Alfredo", "" ] ]
The idea of naturalness, as originally conceived, refers only to the finite renormalization of the Higgs boson mass induced by the introduction of heavier states. In this respect, naturalness is still a powerful heuristic principle in model building beyond the standard model whenever new massive states are coupled to the Higgs field. The most compelling case is provided by the generation of neutrino masses. In this paper we confront this problem from a new perspective. The right-handed sector responsible for the seesaw mechanism---which introduces a large energy threshold above the electroweak scale---is made supersymmetric to comply with naturalness while the standard model is left unchanged and non-supersymmetric. Cancellations necessary to the naturalness requirement break down only at two loops, thus offering the possibility to increase the right-handed neutrino mass scale up to one order of magnitude above the usual values allowed by naturalness. If also the weak boson sector of the standard model is made supersymmetric, cancellations break down at three loops and the scale of new physics can be further raised. In the type-I seesaw, this implementation provides right-handed neutrino masses that are natural and at the same time large enough to give rise to baryogenesis (via leptogenesis). The model contains a dark matter candidate and distinctive new physics in the leptonic sector.
1101.0561
Pavel Nadolsky
Marco Guzzi, Pavel Nadolsky, Edmond Berger, Hung-Liang Lai, Fredrick Olness, and C.-P. Yuan
CT10 parton distributions and other developments in the global QCD analysis
17 pages, 9 figures
null
null
SMU-HEP-10-11
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We summarize several projects carried out by the CTEQ global analysis of parton distribution functions (PDFs) of the proton during 2010. We discuss a recently released CT10 family of PDFs with a fixed and variable QCD coupling strength; implementation of combined HERA and Tevatron lepton asymmetry data sets; theoretical issues associated with the analysis of $W$ charge asymmetry in PDF fits; PDFs for leading-order shower programs; and constraints on new color-octet fermions from the hadronic data.
[ { "created": "Mon, 3 Jan 2011 16:46:10 GMT", "version": "v1" } ]
2011-01-04
[ [ "Guzzi", "Marco", "" ], [ "Nadolsky", "Pavel", "" ], [ "Berger", "Edmond", "" ], [ "Lai", "Hung-Liang", "" ], [ "Olness", "Fredrick", "" ], [ "Yuan", "C. -P.", "" ] ]
We summarize several projects carried out by the CTEQ global analysis of parton distribution functions (PDFs) of the proton during 2010. We discuss a recently released CT10 family of PDFs with a fixed and variable QCD coupling strength; implementation of combined HERA and Tevatron lepton asymmetry data sets; theoretical issues associated with the analysis of $W$ charge asymmetry in PDF fits; PDFs for leading-order shower programs; and constraints on new color-octet fermions from the hadronic data.
2308.07814
Junichiro Kawamura
Junichiro Kawamura and Seodong Shin
Current status on pair-produced muon-philic vectorlike leptons in multilepton channels at the LHC
8 pages, 4 figures; ver2 matched to published version
JHEP11(2023)025
10.1007/JHEP11(2023)025
CTPU-PTC-23-38
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In this work, we obtain the current limits on the pair production of vectorlike leptons decaying to a Standard Model gauge boson and a lepton in the second generation using the Run-2 data at the LHC. Since there is no dedicated search, we recast the ATLAS analyses searching for the type-III seesaw heavy leptons in the multi-lepton channels. There is no limit for the $SU(2)_L$ singlet vectorlike lepton beyond about 100 GeV, while the limit is about 780 GeV for the doublet one. Thus, dedicated searches for the vectorlike leptons are necessary, especially for the singlet one. We also study the general cases of the vectorlike lepton decays and future sensitivities at the HL-LHC.
[ { "created": "Tue, 15 Aug 2023 14:45:42 GMT", "version": "v1" }, { "created": "Wed, 8 Nov 2023 07:15:58 GMT", "version": "v2" } ]
2023-11-09
[ [ "Kawamura", "Junichiro", "" ], [ "Shin", "Seodong", "" ] ]
In this work, we obtain the current limits on the pair production of vectorlike leptons decaying to a Standard Model gauge boson and a lepton in the second generation using the Run-2 data at the LHC. Since there is no dedicated search, we recast the ATLAS analyses searching for the type-III seesaw heavy leptons in the multi-lepton channels. There is no limit for the $SU(2)_L$ singlet vectorlike lepton beyond about 100 GeV, while the limit is about 780 GeV for the doublet one. Thus, dedicated searches for the vectorlike leptons are necessary, especially for the singlet one. We also study the general cases of the vectorlike lepton decays and future sensitivities at the HL-LHC.
hep-ph/9904373
Matthias Steinhauser
M. Steinhauser (Univ. of Bern)
Hadronic contribution to $\alpha(M_Z^2)$ and the anomalous magnetic moment of the muon
6 pages, Talk presented at the 17th International Workshop on Weak Interactions and Neutrinos (WIN99), Cape Town, South Africa, January 24--30, 1999
null
null
BUTP-99/06
hep-ph
null
In this contribution recent developments are discussed which lead to a significant reduction of the error for $\alpha(M_Z^2)$ and $(g-2)_\mu$.
[ { "created": "Sat, 17 Apr 1999 13:43:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Steinhauser", "M.", "", "Univ. of Bern" ] ]
In this contribution recent developments are discussed which lead to a significant reduction of the error for $\alpha(M_Z^2)$ and $(g-2)_\mu$.
hep-ph/0601248
Thomas Hahn
T. Hahn, M. Rauch
News from FormCalc and LoopTools
5 pages, to appear in the proceedings of the 7th International Symposium on Radiative Corrections (RADCOR05), Shonan Village, Japan, 2005
null
10.1016/j.nuclphysbps.2006.03.026
MPP-2006-7
hep-ph
null
The FormCalc package automates the computation of FeynArts amplitudes up to one loop including the generation of a Fortran code for the numerical evaluation of the squared matrix element. Major new or enhanced features in Version 5 are: iterative build-up of essentially arbitrary phase-spaces including cuts, convolution with density functions, and uniform treatment of kinematical variables. The LoopTools library supplies the one-loop integrals necessary for evaluating the squared matrix element. Its most significant extensions in Version 2.2 are the five-point family of integrals, and complex and alternate versions.
[ { "created": "Mon, 30 Jan 2006 14:36:06 GMT", "version": "v1" } ]
2009-11-11
[ [ "Hahn", "T.", "" ], [ "Rauch", "M.", "" ] ]
The FormCalc package automates the computation of FeynArts amplitudes up to one loop including the generation of a Fortran code for the numerical evaluation of the squared matrix element. Major new or enhanced features in Version 5 are: iterative build-up of essentially arbitrary phase-spaces including cuts, convolution with density functions, and uniform treatment of kinematical variables. The LoopTools library supplies the one-loop integrals necessary for evaluating the squared matrix element. Its most significant extensions in Version 2.2 are the five-point family of integrals, and complex and alternate versions.
2206.10642
Matt LeBlanc
Matt LeBlanc, Benjamin Nachman, Christof Sauer
Going off topics to demix quark and gluon jets in $\alpha_S$ extractions
20 pages, 7 figures
J. High Energ. Phys. 2023, 150 (2023)
10.1007/JHEP02(2023)150
null
hep-ph hep-ex physics.data-an
http://creativecommons.org/licenses/by/4.0/
Quantum chromodynamics is the theory of the strong interaction between quarks and gluons; the coupling strength of the interaction, $\alpha_S$, is the least precisely-known of all interactions in nature. An extraction of the strong coupling from the radiation pattern within jets would provide a complementary approach to conventional extractions from jet production rates and hadronic event shapes, and would be a key achievement of jet substructure at the Large Hadron Collider (LHC). Presently, the relative fraction of quark and gluon jets in a sample is the limiting factor in such extractions, as this fraction is degenerate with the value of $\alpha_S$ for the most well-understood observables. To overcome this limitation, we apply recently proposed techniques to statistically demix multiple mixtures of jets and obtain purified quark and gluon distributions based on an operational definition. We illustrate that studying quark and gluon jet substructure separately can significantly improve the sensitivity of such extractions of the strong coupling. We also discuss how using machine learning techniques or infrared- and collinear-unsafe information can improve the demixing performance without the loss of theoretical control. While theoretical research is required to connect the extract topics with the quark and gluon objects in cross section calculations, our study illustrates the potential of demixing to reduce the dominant uncertainty for the $\alpha_S$ extraction from jet substructure at the LHC.
[ { "created": "Tue, 21 Jun 2022 18:00:05 GMT", "version": "v1" }, { "created": "Mon, 1 Aug 2022 13:05:37 GMT", "version": "v2" }, { "created": "Tue, 7 Mar 2023 20:26:42 GMT", "version": "v3" } ]
2023-03-09
[ [ "LeBlanc", "Matt", "" ], [ "Nachman", "Benjamin", "" ], [ "Sauer", "Christof", "" ] ]
Quantum chromodynamics is the theory of the strong interaction between quarks and gluons; the coupling strength of the interaction, $\alpha_S$, is the least precisely-known of all interactions in nature. An extraction of the strong coupling from the radiation pattern within jets would provide a complementary approach to conventional extractions from jet production rates and hadronic event shapes, and would be a key achievement of jet substructure at the Large Hadron Collider (LHC). Presently, the relative fraction of quark and gluon jets in a sample is the limiting factor in such extractions, as this fraction is degenerate with the value of $\alpha_S$ for the most well-understood observables. To overcome this limitation, we apply recently proposed techniques to statistically demix multiple mixtures of jets and obtain purified quark and gluon distributions based on an operational definition. We illustrate that studying quark and gluon jet substructure separately can significantly improve the sensitivity of such extractions of the strong coupling. We also discuss how using machine learning techniques or infrared- and collinear-unsafe information can improve the demixing performance without the loss of theoretical control. While theoretical research is required to connect the extract topics with the quark and gluon objects in cross section calculations, our study illustrates the potential of demixing to reduce the dominant uncertainty for the $\alpha_S$ extraction from jet substructure at the LHC.
0705.0900
S. Weinzierl
Stefan Weinzierl
Feynman integrals and multiple polylogarithms
23 pages, talk given at the workshop "Renormalization and Galois theories", Marseille, March 2006; v2: references added
null
null
null
hep-ph
null
In this talk I review the connections between Feynman integrals and multiple polylogarithms. After an introductory section on loop integrals I discuss the Mellin-Barnes transformation and shuffle algebras. In a subsequent section multiple polylogarithms are introduced. Finally, I discuss how certain Feynman integrals evaluate to multiple polylogarithms.
[ { "created": "Mon, 7 May 2007 12:55:26 GMT", "version": "v1" }, { "created": "Thu, 10 May 2007 06:40:56 GMT", "version": "v2" } ]
2007-05-23
[ [ "Weinzierl", "Stefan", "" ] ]
In this talk I review the connections between Feynman integrals and multiple polylogarithms. After an introductory section on loop integrals I discuss the Mellin-Barnes transformation and shuffle algebras. In a subsequent section multiple polylogarithms are introduced. Finally, I discuss how certain Feynman integrals evaluate to multiple polylogarithms.
1102.1334
Krzysztof Kutak
Krzysztof Kutak
Phenomenology of Jet Production in Forward Direction at High Energy Hadron Colliders
Talk given at 45th Rencontres de Moriond: QCD and Hadronic Interactions, La Thuile, Italy, March 13-20, 2010
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate observables relevant for forward jets at LHC. The simulations are performed using Monte Carlo event generators. In particular we compare results from CASCADE based on high energy factorization and PYTHIA which is based on collinear factorization.
[ { "created": "Mon, 7 Feb 2011 15:36:30 GMT", "version": "v1" } ]
2011-02-08
[ [ "Kutak", "Krzysztof", "" ] ]
We calculate observables relevant for forward jets at LHC. The simulations are performed using Monte Carlo event generators. In particular we compare results from CASCADE based on high energy factorization and PYTHIA which is based on collinear factorization.
hep-ph/0303159
David London
Alakabha Datta and David London
Triple-Product Correlations in B -> V1 V2$ Decays and New Physics
42 pages, LaTeX, no figures. Title changed, several explanatory paragraphs added, references added, analysis and conclusions unchanged
Int.J.Mod.Phys.A19:2505-2544,2004
10.1142/S0217751X04018300
UdeM-GPP-TH-03-108
hep-ph
null
In this paper we examine T-violating triple-product correlations (TP's) in B -> V1 V2 decays. TP's are excellent probes of physics beyond the standard model (SM) for two reasons: (i) within the SM, most TP's are expected to be tiny, and (ii) unlike direct CP asymmetries, TP's are not suppressed by the small strong phases which are expected in B decays. TP's are obtained via the angular analysis of B -> V1 V2. In a general analysis based on factorization, we demonstrate that the most promising decays for measuring TP's in the SM involve excited final-state vector mesons, and we provide estimates of such TP's. We find that there are only a handful of decays in which large TP's are possible, and the size of these TP's depends strongly on the size of nonfactorizable effects. We show that TP's which vanish in the SM can be very large in models with new physics. The measurement of a nonzero TP asymmetry in a decay where none is expected would specifically point to new physics involving large couplings to the right-handed b-quark.
[ { "created": "Wed, 19 Mar 2003 00:10:23 GMT", "version": "v1" }, { "created": "Wed, 19 Mar 2003 21:26:40 GMT", "version": "v2" }, { "created": "Thu, 4 Dec 2003 19:32:58 GMT", "version": "v3" } ]
2014-11-17
[ [ "Datta", "Alakabha", "" ], [ "London", "David", "" ] ]
In this paper we examine T-violating triple-product correlations (TP's) in B -> V1 V2 decays. TP's are excellent probes of physics beyond the standard model (SM) for two reasons: (i) within the SM, most TP's are expected to be tiny, and (ii) unlike direct CP asymmetries, TP's are not suppressed by the small strong phases which are expected in B decays. TP's are obtained via the angular analysis of B -> V1 V2. In a general analysis based on factorization, we demonstrate that the most promising decays for measuring TP's in the SM involve excited final-state vector mesons, and we provide estimates of such TP's. We find that there are only a handful of decays in which large TP's are possible, and the size of these TP's depends strongly on the size of nonfactorizable effects. We show that TP's which vanish in the SM can be very large in models with new physics. The measurement of a nonzero TP asymmetry in a decay where none is expected would specifically point to new physics involving large couplings to the right-handed b-quark.
1106.2322
Alan Barr
Alan J. Barr, Sky T. French, James A. Frost, Christopher G. Lester
Speedy Higgs boson discovery in decays to tau lepton pairs : h->tau,tau
4 pages. 3 figures. Additional material in version 2: Figure 2c (distribution of m_tautau^true), Figure 3 (showing the relative sensitivity of different projections), related discussion
null
10.1007/JHEP10(2011)080
Cavendish-HEP-11/12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Discovery of the Higgs boson in any decay channel depends on the existence of event variables or cuts with sensitivity to the presence of the Higgs. We demonstrate the non-optimality of the kinematic variables which are currently expected to play the largest role in the discovery (or exclusion) of the Higgs at the LHC in the tau channel. Any LHC collaboration looking for opportunities to gain advantages over its rivals should, perhaps, consider the alternative strategy we propose.
[ { "created": "Sun, 12 Jun 2011 16:09:54 GMT", "version": "v1" }, { "created": "Mon, 12 Sep 2011 00:17:48 GMT", "version": "v2" } ]
2015-05-28
[ [ "Barr", "Alan J.", "" ], [ "French", "Sky T.", "" ], [ "Frost", "James A.", "" ], [ "Lester", "Christopher G.", "" ] ]
Discovery of the Higgs boson in any decay channel depends on the existence of event variables or cuts with sensitivity to the presence of the Higgs. We demonstrate the non-optimality of the kinematic variables which are currently expected to play the largest role in the discovery (or exclusion) of the Higgs at the LHC in the tau channel. Any LHC collaboration looking for opportunities to gain advantages over its rivals should, perhaps, consider the alternative strategy we propose.
1710.02284
Chul Kim
Junegone Chay, Chul Kim
Threshold Factorization Redux
20 pages, 2 figures; matches published version
Phys. Rev. D 97, 094024 (2018)
10.1103/PhysRevD.97.094024
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reanalyze the factorization theorems for Drell-Yan process and for deep inelastic scattering near threshold, as constructed in the framework of the soft-collinear effective theory (SCET), from a new, consistent perspective. In order to formulate the factorization near threshold in SCET, we should include an additional degree of freedom with small energy, collinear to the beam direction. The corresponding collinear-soft mode is included to describe the parton distribution function (PDF) near threshold. The soft function is modified by subtracting the contribution of the collinear-soft modes in order to avoid double counting on the overlap region. As a result, the proper soft function becomes infrared finite, and all the factorized parts are free of rapidity divergence. Furthermore, the separation of the relevant scales in each factorized part becomes manifest. We apply the same idea to the dihadron production in $e^+ e^-$ annihilation near threshold, and show that the resultant soft function is also free of infrared and rapidity divergences.
[ { "created": "Fri, 6 Oct 2017 06:21:07 GMT", "version": "v1" }, { "created": "Wed, 23 May 2018 14:22:00 GMT", "version": "v2" } ]
2018-05-30
[ [ "Chay", "Junegone", "" ], [ "Kim", "Chul", "" ] ]
We reanalyze the factorization theorems for Drell-Yan process and for deep inelastic scattering near threshold, as constructed in the framework of the soft-collinear effective theory (SCET), from a new, consistent perspective. In order to formulate the factorization near threshold in SCET, we should include an additional degree of freedom with small energy, collinear to the beam direction. The corresponding collinear-soft mode is included to describe the parton distribution function (PDF) near threshold. The soft function is modified by subtracting the contribution of the collinear-soft modes in order to avoid double counting on the overlap region. As a result, the proper soft function becomes infrared finite, and all the factorized parts are free of rapidity divergence. Furthermore, the separation of the relevant scales in each factorized part becomes manifest. We apply the same idea to the dihadron production in $e^+ e^-$ annihilation near threshold, and show that the resultant soft function is also free of infrared and rapidity divergences.
1306.4472
Viacheslav Kudryavtsev
V.A.Kudryavtsev (Petersburg Nuclear Physics Institute)
Heavy states of hadron string as weak interacting massive particles for Dark Matter
4 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Massive states (of order 10 Gev and more) of hadron string (with scale 1 Gev) can have very small coupling constants with usual baryons of the Universe. Corresponding mean times for them are found to be order and even more than the age of the Universe. They are proposed as possible candidates for weak interacting massive particles (WIMP) of Dark Matter.
[ { "created": "Wed, 19 Jun 2013 10:01:04 GMT", "version": "v1" } ]
2013-06-20
[ [ "Kudryavtsev", "V. A.", "", "Petersburg Nuclear Physics Institute" ] ]
Massive states (of order 10 Gev and more) of hadron string (with scale 1 Gev) can have very small coupling constants with usual baryons of the Universe. Corresponding mean times for them are found to be order and even more than the age of the Universe. They are proposed as possible candidates for weak interacting massive particles (WIMP) of Dark Matter.
2302.01274
Ji-Chong Yang Mr
Shuai Zhang and Ji-Chong Yang and Yu-Chen Guo
Using k-means assistant event selection strategy to study anomalous quartic gauge couplings at muon colliders
15 pages, 8 figures
Eur. Phys. J. C (2024) 84:142
10.1140/epjc/s10052-024-12494-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The search for new physics beyond the Standard Model is one of the central problems of current high energy physics interest. As the luminosities of current and near-future colliders continue to increase, the search for new physics has increased the requirements for processing large amounts of data. Meanwhile, quantum computing which is rapidly evolving, has great potential to become a powerful tool to help search for new physics signals. Since the k-means algorithm is known to be able to be accelerated with the help of quantum computing, we investigate and propose an event selection strategy based on k-means algorithm to search for new physics signals. Taking the case of tri-photon processes at the muon colliders as an example, the event selection strategy is shown to be effective in helping to search for the signals of dimension-8 operators contributing to anomalous quartic gauge couplings. Compared with traditional event selection strategy, the expected constraints are generally tighter.
[ { "created": "Thu, 2 Feb 2023 18:05:26 GMT", "version": "v1" }, { "created": "Tue, 27 Feb 2024 06:35:51 GMT", "version": "v2" } ]
2024-02-28
[ [ "Zhang", "Shuai", "" ], [ "Yang", "Ji-Chong", "" ], [ "Guo", "Yu-Chen", "" ] ]
The search for new physics beyond the Standard Model is one of the central problems of current high energy physics interest. As the luminosities of current and near-future colliders continue to increase, the search for new physics has increased the requirements for processing large amounts of data. Meanwhile, quantum computing which is rapidly evolving, has great potential to become a powerful tool to help search for new physics signals. Since the k-means algorithm is known to be able to be accelerated with the help of quantum computing, we investigate and propose an event selection strategy based on k-means algorithm to search for new physics signals. Taking the case of tri-photon processes at the muon colliders as an example, the event selection strategy is shown to be effective in helping to search for the signals of dimension-8 operators contributing to anomalous quartic gauge couplings. Compared with traditional event selection strategy, the expected constraints are generally tighter.
1210.5427
Josip Trampetic Dr.
Josip Trampetic
High energy cosmic rays experiments inspired by noncommutative quantum field theory
11 pages, 8 figures, Based on the plenary session talks given at the conference: 5th Petrov International Symposium: "High Energy Physics, Cosmology and Gravity", BITP, Kyiv, Ukraine 2012
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Phenomenological analysis of the covariant theta-exact noncommutative (NC) gauge field theory (GFT), inspired by high energy cosmic rays experiments, is performed in the framework of the inelastic neutrino-nucleon scatterings, plasmon and $Z$-boson decays into neutrino pair, the Big Bang Nucleosynthesis (BBN) and the Reheating Phase After Inflation (RPAI), respectively. Next we have have found neutrino two-point function and shows a closed form decoupling of the hard ultraviolet (UV) divergent term from softened ultraviolet/infrared (UV/IR) mixing term and from the finite terms as well. For a certain choice of the noncommutative parameter theta which preserves unitarity, problematic UV divergent and UV/IR mixing terms vanish. Non-perturbative modifications of the neutrino dispersion relations are assymptotically independent of the scale of noncommutativity in both the low and high energy limits and may allow superluminal propagation.
[ { "created": "Fri, 19 Oct 2012 14:20:52 GMT", "version": "v1" } ]
2012-10-22
[ [ "Trampetic", "Josip", "" ] ]
Phenomenological analysis of the covariant theta-exact noncommutative (NC) gauge field theory (GFT), inspired by high energy cosmic rays experiments, is performed in the framework of the inelastic neutrino-nucleon scatterings, plasmon and $Z$-boson decays into neutrino pair, the Big Bang Nucleosynthesis (BBN) and the Reheating Phase After Inflation (RPAI), respectively. Next we have have found neutrino two-point function and shows a closed form decoupling of the hard ultraviolet (UV) divergent term from softened ultraviolet/infrared (UV/IR) mixing term and from the finite terms as well. For a certain choice of the noncommutative parameter theta which preserves unitarity, problematic UV divergent and UV/IR mixing terms vanish. Non-perturbative modifications of the neutrino dispersion relations are assymptotically independent of the scale of noncommutativity in both the low and high energy limits and may allow superluminal propagation.
hep-ph/9811340
null
Hsiang-nan Li
$k_T$ and threshold resummations
25 pages in a latex file, 1 figure in a postscript file, revised version to appear in Chin. J. Phys
null
null
NCKU-HEP-98-11
hep-ph
null
We demonstrate that both the $k_T$ and threshold resummations can be performed in the Collins-Soper resummation formalism by evaluating soft gluon emissions with infrared cutoffs for the longitudinal and transverse loop momenta, respectively. The reason the $k_T$ resummation for a parton distribution function leads to suppression in the large $b$ region, $b$ being the conjugate variable of parton transverse momentum $k_T$, and the threshold resummation leads to enhancement in the large $N$ limit, $N$ being the moment of a distribution function, is a consequence of opposite directions of double-logarithm evolutions. The $k_T$ and threshold resummations for an energetic final-state jet give suppression. The switch of the threshold resummation from enhancement to suppression is attributed to a nonvanishing jet invariant mass. In the same framework we derive a unification of the $k_T$ and threshold resummations for a parton distribution function by requiring infrared cutoffs for both longitudinal and transverse loop momenta. This unified resummation exhibits suppression at large $b$, similar to the $k_T$ resummation, and exhibits enhancement at small $b$, similar to the threshold resummation.
[ { "created": "Mon, 16 Nov 1998 10:09:11 GMT", "version": "v1" }, { "created": "Thu, 8 Jul 1999 05:42:57 GMT", "version": "v2" } ]
2007-05-23
[ [ "Li", "Hsiang-nan", "" ] ]
We demonstrate that both the $k_T$ and threshold resummations can be performed in the Collins-Soper resummation formalism by evaluating soft gluon emissions with infrared cutoffs for the longitudinal and transverse loop momenta, respectively. The reason the $k_T$ resummation for a parton distribution function leads to suppression in the large $b$ region, $b$ being the conjugate variable of parton transverse momentum $k_T$, and the threshold resummation leads to enhancement in the large $N$ limit, $N$ being the moment of a distribution function, is a consequence of opposite directions of double-logarithm evolutions. The $k_T$ and threshold resummations for an energetic final-state jet give suppression. The switch of the threshold resummation from enhancement to suppression is attributed to a nonvanishing jet invariant mass. In the same framework we derive a unification of the $k_T$ and threshold resummations for a parton distribution function by requiring infrared cutoffs for both longitudinal and transverse loop momenta. This unified resummation exhibits suppression at large $b$, similar to the $k_T$ resummation, and exhibits enhancement at small $b$, similar to the threshold resummation.
1005.2681
Basudeb Dasgupta
Basudeb Dasgupta
Physics and Astrophysics Opportunities with Supernova Neutrinos
v2: 9 pages, including 1 Table. Invited review at ICHEP 2010. Update of previous version which was an invited review at Electroweak Session of Rencontres de Moriond 2010
PoS ICHEP2010:294,2010
null
null
hep-ph astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrinos emitted from a supernova encode useful information about neutrino physics and astrophysics. Interpreting the neutrino signal depends crucially on understanding neutrino production, flavor mixing during propagation, and detection. In this talk, we review the physics potential of a SN neutrino observation.
[ { "created": "Sat, 15 May 2010 15:05:12 GMT", "version": "v1" }, { "created": "Wed, 24 Nov 2010 16:47:59 GMT", "version": "v2" } ]
2011-04-22
[ [ "Dasgupta", "Basudeb", "" ] ]
Neutrinos emitted from a supernova encode useful information about neutrino physics and astrophysics. Interpreting the neutrino signal depends crucially on understanding neutrino production, flavor mixing during propagation, and detection. In this talk, we review the physics potential of a SN neutrino observation.
1802.02657
Michael Paraskevas Dr
Michael Paraskevas
Dirac and Majorana Feynman Rules with four-fermions
22 pages, 2 figures. v2: Few minors, prepared for journal submission
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A compact method for amplitude calculations in theories with Dirac and Majorana effective operators is discussed. Using the renormalizable formalism of Denner et al., [1,2] for propagators, vertices and fermion (number) flow and introducing new "reading-rules", it is shown that fermions can be treated as scalars in the diagrams. The effect of Fermi-statistics appears only in overall signs and is determined once for whole classes of diagrams. Each vertex in this method corresponds to two or more vertices in the standard treatment of effective theories. As such, the advantages of this approach grow together with the number of four-fermion vertices in a given diagram. The discussion develops around effective field theories based on the Standard Model, up to four-fermions and to any order in perturbation theory. Even so, the framework is more general and can be applied elsewhere.
[ { "created": "Wed, 7 Feb 2018 22:08:12 GMT", "version": "v1" }, { "created": "Thu, 1 Mar 2018 14:01:04 GMT", "version": "v2" } ]
2018-03-02
[ [ "Paraskevas", "Michael", "" ] ]
A compact method for amplitude calculations in theories with Dirac and Majorana effective operators is discussed. Using the renormalizable formalism of Denner et al., [1,2] for propagators, vertices and fermion (number) flow and introducing new "reading-rules", it is shown that fermions can be treated as scalars in the diagrams. The effect of Fermi-statistics appears only in overall signs and is determined once for whole classes of diagrams. Each vertex in this method corresponds to two or more vertices in the standard treatment of effective theories. As such, the advantages of this approach grow together with the number of four-fermion vertices in a given diagram. The discussion develops around effective field theories based on the Standard Model, up to four-fermions and to any order in perturbation theory. Even so, the framework is more general and can be applied elsewhere.
1512.08928
Juan Rojo
J. Katharina Behr, Daniela Bortoletto, James A. Frost, Nathan P. Hartland, Cigdem Issever and Juan Rojo
Boosting Higgs pair production in the $b\bar{b}b\bar{b}$ final state with multivariate techniques
47 pages, 22 figures. v2: updated references, added comparison of post-MVA kinematic distributions. v3: matches published version in EPJC
null
10.1140/epjc/s10052-016-4215-5
OUTP-15-14P
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The measurement of Higgs pair production will be a cornerstone of the LHC program in the coming years. Double Higgs production provides a crucial window upon the mechanism of electroweak symmetry breaking and has a unique sensitivity to the Higgs trilinear coupling. We study the feasibility of a measurement of Higgs pair production in the $b\bar{b}b\bar{b}$ final state at the LHC. Our analysis is based on a combination of traditional cut-based methods with state-of-the-art multivariate techniques. We account for all relevant backgrounds, including the contributions from light and charm jet mis-identification, which are ultimately comparable in size to the irreducible $4b$ QCD background. We demonstrate the robustness of our analysis strategy in a high pileup environment. For an integrated luminosity of $\mathcal{L}=3$ ab$^{-1}$, a signal significance of $S/\sqrt{B}\simeq 3$ is obtained, indicating that the $b\bar{b}b\bar{b}$ final state alone could allow for the observation of double Higgs production at the High-Luminosity LHC.
[ { "created": "Wed, 30 Dec 2015 12:51:06 GMT", "version": "v1" }, { "created": "Wed, 20 Jan 2016 10:31:35 GMT", "version": "v2" }, { "created": "Mon, 20 Jun 2016 11:05:41 GMT", "version": "v3" } ]
2016-08-03
[ [ "Behr", "J. Katharina", "" ], [ "Bortoletto", "Daniela", "" ], [ "Frost", "James A.", "" ], [ "Hartland", "Nathan P.", "" ], [ "Issever", "Cigdem", "" ], [ "Rojo", "Juan", "" ] ]
The measurement of Higgs pair production will be a cornerstone of the LHC program in the coming years. Double Higgs production provides a crucial window upon the mechanism of electroweak symmetry breaking and has a unique sensitivity to the Higgs trilinear coupling. We study the feasibility of a measurement of Higgs pair production in the $b\bar{b}b\bar{b}$ final state at the LHC. Our analysis is based on a combination of traditional cut-based methods with state-of-the-art multivariate techniques. We account for all relevant backgrounds, including the contributions from light and charm jet mis-identification, which are ultimately comparable in size to the irreducible $4b$ QCD background. We demonstrate the robustness of our analysis strategy in a high pileup environment. For an integrated luminosity of $\mathcal{L}=3$ ab$^{-1}$, a signal significance of $S/\sqrt{B}\simeq 3$ is obtained, indicating that the $b\bar{b}b\bar{b}$ final state alone could allow for the observation of double Higgs production at the High-Luminosity LHC.
2105.01435
Valery Lyubovitskij
Stanley J. Brodsky, Valery E. Lyubovitskij, Ivan Schmidt
The Diffractive Contribution to Deep Inelastic Lepton-Proton Scattering: Implications for QCD Momentum Sum Rules and Parton Distributions
8 pages, 4 figures
Phys. Lett. B 824, 136801 (2022)
10.1016/j.physletb.2021.136801
SLAC-PUB-17599
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cross section for deep inelastic lepton-proton scattering (DIS) $\ell p \to \ell' X$ includes a diffractive deep inelastic (DDIS) contribution $\ell p \to \ell' p' X$, in which the proton remains intact with a large longitudinal momentum fraction $x_F$ greater than 0.9 and small transverse momentum. The DDIS events, which can be identified with Pomeron exchange in the $t$-channel, account for approximately $10\%$ of all of the DIS events. Thus, when one measures DIS, one automatically includes the leading-twist Bjorken-scaling DDIS events as a contribution to the DIS cross section, whether or not the final-state proton $p'$ is detected. In such events, the missing momentum fraction $x_{p'} \sim 0.9$ carried by the final-state proton $p'$ in the DDIS events could be misidentified with the light-front momentum fraction carried by sea quarks or gluons in the protons' Fock structure. As we shall show in this article, the underlying QCD Pomeron-exchange amplitude which produces the DDIS events does not obey the operator product expansion nor satisfy momentum sum rules. Thus we conclude that the quark and gluon distributions measured in DIS experiments will be misidentified, unless the measurements explicitly exclude the DDIS events and that a correct determination of the parton distribution functions (PDFs) derived from the DIS data requires the explicit subtraction of the DDIS contribution from the full DIS cross section.
[ { "created": "Tue, 4 May 2021 11:55:33 GMT", "version": "v1" }, { "created": "Fri, 3 Dec 2021 17:17:45 GMT", "version": "v2" } ]
2021-12-06
[ [ "Brodsky", "Stanley J.", "" ], [ "Lyubovitskij", "Valery E.", "" ], [ "Schmidt", "Ivan", "" ] ]
The cross section for deep inelastic lepton-proton scattering (DIS) $\ell p \to \ell' X$ includes a diffractive deep inelastic (DDIS) contribution $\ell p \to \ell' p' X$, in which the proton remains intact with a large longitudinal momentum fraction $x_F$ greater than 0.9 and small transverse momentum. The DDIS events, which can be identified with Pomeron exchange in the $t$-channel, account for approximately $10\%$ of all of the DIS events. Thus, when one measures DIS, one automatically includes the leading-twist Bjorken-scaling DDIS events as a contribution to the DIS cross section, whether or not the final-state proton $p'$ is detected. In such events, the missing momentum fraction $x_{p'} \sim 0.9$ carried by the final-state proton $p'$ in the DDIS events could be misidentified with the light-front momentum fraction carried by sea quarks or gluons in the protons' Fock structure. As we shall show in this article, the underlying QCD Pomeron-exchange amplitude which produces the DDIS events does not obey the operator product expansion nor satisfy momentum sum rules. Thus we conclude that the quark and gluon distributions measured in DIS experiments will be misidentified, unless the measurements explicitly exclude the DDIS events and that a correct determination of the parton distribution functions (PDFs) derived from the DIS data requires the explicit subtraction of the DDIS contribution from the full DIS cross section.
1011.5037
Gautam Bhattacharyya
Asmaa Abada, Gautam Bhattacharyya, Debottam Das, C\'edric Weiland
A possible connection between neutrino mass generation and the lightness of a NMSSM pseudoscalar
8 pages; v2: version to appear in PLB
Phys.Lett.B700:351-355,2011
10.1016/j.physletb.2011.05.020
LPT Orsay/10-54, SINP/TNP/2010/10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the interesting properties of the NMSSM is that it can accommodate a light pseudoscalar of order 10 GeV. However, such scenarios are challenged by several experimental constraints, especially those related to the fermionic decays of the pseudoscalar. In this Letter, we extend the NMSSM field content by two gauge singlets, with lepton numbers +1 and -1. This serves the twin purpose of generating neutrino masses via the inverse see-saw mechanism and keeping the option of a very light pseudoscalar experimentally viable by opening dominant invisible decay channels of the pseudoscalar which help it evade the existing bounds.
[ { "created": "Tue, 23 Nov 2010 09:31:49 GMT", "version": "v1" }, { "created": "Thu, 19 May 2011 10:49:52 GMT", "version": "v2" } ]
2011-07-15
[ [ "Abada", "Asmaa", "" ], [ "Bhattacharyya", "Gautam", "" ], [ "Das", "Debottam", "" ], [ "Weiland", "Cédric", "" ] ]
One of the interesting properties of the NMSSM is that it can accommodate a light pseudoscalar of order 10 GeV. However, such scenarios are challenged by several experimental constraints, especially those related to the fermionic decays of the pseudoscalar. In this Letter, we extend the NMSSM field content by two gauge singlets, with lepton numbers +1 and -1. This serves the twin purpose of generating neutrino masses via the inverse see-saw mechanism and keeping the option of a very light pseudoscalar experimentally viable by opening dominant invisible decay channels of the pseudoscalar which help it evade the existing bounds.
hep-ph/0208226
Sechul Oh
B. Dutta, C.S. Kim, and Sechul Oh
A Consistent Resolution of Possible Anomalies in B^0 --> phi K_S and B^+ --> eta' K^+ Decays
14 pages, 2 figures, Revtex, minor changes, to appear in Phys. Rev. Lett
Phys.Rev.Lett. 90 (2003) 011801
10.1103/PhysRevLett.90.011801
null
hep-ph
null
In the framework of R-parity violating (\rpv) supersymmetry, we try to find a consistent explanation for both recently measured CP asymmetry in B^0 --> phi K_S decay and the large branching ratio of B^{+/-} --> eta' K^{+/-} decay, which are inconsistent with the Standard Model (SM) prediction. We also investigate other charmless hadronic B --> PP and B --> VP decay modes whose experimental data favor the SM: for instance, recently measured CP asymmetries in B^0 --> eta^{prime} K_S and B^0 --> J / Psi K_S. We find that all the observed data can be accommodated for certain values of \rpv couplings.
[ { "created": "Sun, 25 Aug 2002 18:10:19 GMT", "version": "v1" }, { "created": "Mon, 25 Nov 2002 07:19:38 GMT", "version": "v2" } ]
2009-11-07
[ [ "Dutta", "B.", "" ], [ "Kim", "C. S.", "" ], [ "Oh", "Sechul", "" ] ]
In the framework of R-parity violating (\rpv) supersymmetry, we try to find a consistent explanation for both recently measured CP asymmetry in B^0 --> phi K_S decay and the large branching ratio of B^{+/-} --> eta' K^{+/-} decay, which are inconsistent with the Standard Model (SM) prediction. We also investigate other charmless hadronic B --> PP and B --> VP decay modes whose experimental data favor the SM: for instance, recently measured CP asymmetries in B^0 --> eta^{prime} K_S and B^0 --> J / Psi K_S. We find that all the observed data can be accommodated for certain values of \rpv couplings.
hep-ph/0205329
Gustavo Burdman
Gustavo Burdman
Constraints on the Bulk Standard Model in the Randall-Sundrum Scenario
18 pages, 2 ps figures
Phys.Rev. D66 (2002) 076003
10.1103/PhysRevD.66.076003
null
hep-ph hep-ex hep-th
null
We derive constraints on the Randall-Sundrum scenario with the standard model fields in the bulk. These result from tree level effects associated with the deformation of the zero mode wave-functions of the W and the Z once electroweak symmetry is broken. Recently Cs\'{a}ki, Erlich and Terning pointed out that this implies large contributions to electroweak oblique parameters. Here we find that when fermions are allowed in the bulk the couplings of the $W$ and the $Z$ to zero-mode fermions are also affected. We perform a fit to electroweak observables assuming universal bulk fermion masses and including all effects and find constraints that are considerably stronger than for the case with fermions localized in the low energy boundary. These put the lowest Kaluza-Klein excitation out of reach of the Large Hadron Collider. We then relax the universality assumption and study the effects of flavor violation in the bulk and its possible signatures.
[ { "created": "Wed, 29 May 2002 19:03:21 GMT", "version": "v1" } ]
2009-11-07
[ [ "Burdman", "Gustavo", "" ] ]
We derive constraints on the Randall-Sundrum scenario with the standard model fields in the bulk. These result from tree level effects associated with the deformation of the zero mode wave-functions of the W and the Z once electroweak symmetry is broken. Recently Cs\'{a}ki, Erlich and Terning pointed out that this implies large contributions to electroweak oblique parameters. Here we find that when fermions are allowed in the bulk the couplings of the $W$ and the $Z$ to zero-mode fermions are also affected. We perform a fit to electroweak observables assuming universal bulk fermion masses and including all effects and find constraints that are considerably stronger than for the case with fermions localized in the low energy boundary. These put the lowest Kaluza-Klein excitation out of reach of the Large Hadron Collider. We then relax the universality assumption and study the effects of flavor violation in the bulk and its possible signatures.
hep-ph/0305104
Santi Peris
T. Hambye, S. Peris and E. de Rafael
Delta I=1/2 and epsilon'/epsilon in Large-Nc QCD
25 pages, 8 figures, LaTeX file. Couple of references added
JHEP 0305:027,2003
10.1088/1126-6708/2003/05/027
null
hep-ph hep-lat
null
We present new results for the matrix elements of the Q_6 and Q_4 penguin operators, evaluated in a large-Nc approach which incorporates important O(N_c^2\frac{n_f}{N_c}) unfactorized contributions. Our approach shows analytic matching between short- and long-distance scale dependences within dimensional renormalization schemes, such as MS-bar. Numerically, we find that there is a large positive contribution to the Delta I =1/2 matrix element of Q_6 and hence to the direct CP-violation parameter epsilon'/epsilon. We also present results for the Delta I = 1/2 rule in K -> pi pi amplitudes, which incorporate the related and important ``eye-diagram'' contributions of O(N_c^2\frac{1}{N_c}) from the Q_2 operator (i.e. the penguin-like contraction). The results lead to an enhancement of the Delta I = 1/2 effective coupling. The origin of the large unfactorized contributions which we find is discussed in terms of the relevant scales of the problem.
[ { "created": "Fri, 9 May 2003 16:34:04 GMT", "version": "v1" }, { "created": "Fri, 30 May 2003 16:20:38 GMT", "version": "v2" } ]
2010-02-03
[ [ "Hambye", "T.", "" ], [ "Peris", "S.", "" ], [ "de Rafael", "E.", "" ] ]
We present new results for the matrix elements of the Q_6 and Q_4 penguin operators, evaluated in a large-Nc approach which incorporates important O(N_c^2\frac{n_f}{N_c}) unfactorized contributions. Our approach shows analytic matching between short- and long-distance scale dependences within dimensional renormalization schemes, such as MS-bar. Numerically, we find that there is a large positive contribution to the Delta I =1/2 matrix element of Q_6 and hence to the direct CP-violation parameter epsilon'/epsilon. We also present results for the Delta I = 1/2 rule in K -> pi pi amplitudes, which incorporate the related and important ``eye-diagram'' contributions of O(N_c^2\frac{1}{N_c}) from the Q_2 operator (i.e. the penguin-like contraction). The results lead to an enhancement of the Delta I = 1/2 effective coupling. The origin of the large unfactorized contributions which we find is discussed in terms of the relevant scales of the problem.
hep-ph/0109150
Andre de Gouvea
Andre de Gouvea
Theoretical Aspects of Neutrino Oscillation
Invited Plenary Talk at the NUFACT'01 Conference, 14 pages, 2 figures
Nucl.Instrum.Meth. A503 (2001) 4-12
10.1016/S0168-9002(03)00634-X
null
hep-ph
null
I review some aspects concerning the physics of neutrino mixing and oscillations. I discuss in some detail the physical neutrino oscillations parameter space in the case of two and three family mixing, and briefly describe the current knowledge of neutrino mixing parameters according to the present solar, atmospheric, and reactor neutrino data. I also briefly comment on the possibility of solving the LNSD anomaly together with the solar and atmospheric ones. I conclude by emphasising that that even though in five to ten years time a lot will be learnt from the next round of neutrino experiments, a great deal about neutrino masses and neutrino mixing will remain unknown.
[ { "created": "Mon, 17 Sep 2001 18:13:43 GMT", "version": "v1" } ]
2009-11-07
[ [ "de Gouvea", "Andre", "" ] ]
I review some aspects concerning the physics of neutrino mixing and oscillations. I discuss in some detail the physical neutrino oscillations parameter space in the case of two and three family mixing, and briefly describe the current knowledge of neutrino mixing parameters according to the present solar, atmospheric, and reactor neutrino data. I also briefly comment on the possibility of solving the LNSD anomaly together with the solar and atmospheric ones. I conclude by emphasising that that even though in five to ten years time a lot will be learnt from the next round of neutrino experiments, a great deal about neutrino masses and neutrino mixing will remain unknown.
2406.10257
Vadim Dmitriev
V.V. Dmitriev, S.A. Smolyansky, V.A. Tseryupa
Analysis of the Third Harmonic of a Vacuum Response in a Subcritical Laser Field
null
Phys. Atom. Nuclei 86 (2023) 913-916
10.1134/S1063778823050137
null
hep-ph hep-th physics.plasm-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
We investigate a nonlinear response of the physical vacuum by the example of the third harmonic in radiation of the electron-positron-photon plasma excited by a strong time dependent electric field at the focus spot of counterpropagating laser pulses. The investigation was developed within the framework of the Bogoliubov-Born-Green-Kirkwood-Yvon kinetic theory nonperturbatively describing vacuum creation of the quasiparticle electron-positron plasma (EPP) and different channels of its interaction with the photon subsystem in the single-photon approximation that are opened in the presence of a strong semiclassical field. We investigate the radiation of EPP in the annihilation channel on the basis of the well known approximations and compare the obtained result with the semiclassical radiation of the plasma oscillations. In the high-frequency range for large adiabaticity parameter the quantum radiation dominates in comparison with the semiclassical one.
[ { "created": "Mon, 10 Jun 2024 17:07:07 GMT", "version": "v1" } ]
2024-06-18
[ [ "Dmitriev", "V. V.", "" ], [ "Smolyansky", "S. A.", "" ], [ "Tseryupa", "V. A.", "" ] ]
We investigate a nonlinear response of the physical vacuum by the example of the third harmonic in radiation of the electron-positron-photon plasma excited by a strong time dependent electric field at the focus spot of counterpropagating laser pulses. The investigation was developed within the framework of the Bogoliubov-Born-Green-Kirkwood-Yvon kinetic theory nonperturbatively describing vacuum creation of the quasiparticle electron-positron plasma (EPP) and different channels of its interaction with the photon subsystem in the single-photon approximation that are opened in the presence of a strong semiclassical field. We investigate the radiation of EPP in the annihilation channel on the basis of the well known approximations and compare the obtained result with the semiclassical radiation of the plasma oscillations. In the high-frequency range for large adiabaticity parameter the quantum radiation dominates in comparison with the semiclassical one.
2111.07586
Manfred Lindner
M. Sajjad Athar, Steven W. Barwick, Thomas Brunner, Jun Cao, Mikhail Danilov, Kunio Inoue, Takaaki Kajita, Marek Kowalski, Manfred Lindner, Kenneth R. Long, Nathalie Palanque-Delabrouille, Werner Rodejohann, Heidi Schellman, Kate Scholberg, Seon-Hee Seo, Nigel J.T. Smith, Walter Winter, Geralyn P. Zeller, Renata Zukanovich Funchal
Status and Perspectives of Neutrino Physics
227 pages; this review of the field of neutrino physics emerged from a report written by a panel on the request of IUPAP (International Union of Pure and Applied Physics). The mandate, the panel members and the report can be found on the web page of the panel at ht tps://www.iupapneutrinopanel.org
null
10.1016/j.ppnp.2022.103947
null
hep-ph astro-ph.IM hep-ex nucl-ex
http://creativecommons.org/licenses/by-nc-nd/4.0/
This review demonstrates the unique role of the neutrino by discussing in detail the physics of and with neutrinos. We deal with neutrino sources, neutrino oscillations, absolute masses, interactions, the possible existence of sterile neutrinos, and theoretical implications. In addition, synergies of neutrino physics with other research fields are found, and requirements to continue successful neutrino physics in the future, in terms of technological developments and adequate infrastructures, are stressed.
[ { "created": "Mon, 15 Nov 2021 08:07:21 GMT", "version": "v1" } ]
2022-03-23
[ [ "Athar", "M. Sajjad", "" ], [ "Barwick", "Steven W.", "" ], [ "Brunner", "Thomas", "" ], [ "Cao", "Jun", "" ], [ "Danilov", "Mikhail", "" ], [ "Inoue", "Kunio", "" ], [ "Kajita", "Takaaki", "" ], [ "Kowalski", "Marek", "" ], [ "Lindner", "Manfred", "" ], [ "Long", "Kenneth R.", "" ], [ "Palanque-Delabrouille", "Nathalie", "" ], [ "Rodejohann", "Werner", "" ], [ "Schellman", "Heidi", "" ], [ "Scholberg", "Kate", "" ], [ "Seo", "Seon-Hee", "" ], [ "Smith", "Nigel J. T.", "" ], [ "Winter", "Walter", "" ], [ "Zeller", "Geralyn P.", "" ], [ "Funchal", "Renata Zukanovich", "" ] ]
This review demonstrates the unique role of the neutrino by discussing in detail the physics of and with neutrinos. We deal with neutrino sources, neutrino oscillations, absolute masses, interactions, the possible existence of sterile neutrinos, and theoretical implications. In addition, synergies of neutrino physics with other research fields are found, and requirements to continue successful neutrino physics in the future, in terms of technological developments and adequate infrastructures, are stressed.
1810.12261
Johannes Bl\"umlein
J. Ablinger, J. Bl\"umlein, P. Marquard, N. Rana, and C. Schneider
Automated Solution of First Order Factorizable Systems of Differential Equations in One Variable
39 pages Latex, 19 figures, 2 style files, and anc-files
null
10.1016/j.nuclphysb.2018.12.010
DESY 18--053, DO--TH 18/09, TIF-UNIMI-2018-8
hep-ph hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an algorithm which allows to solve analytically linear systems of differential equations which factorize to first order. The solution is given in terms of iterated integrals over an alphabet where its structure is implied by the coefficient matrix of the differential equations. These systems appear in a large variety of higher order calculations in perturbative Quantum Field Theories. We apply this method to calculate the master integrals of the three--loop massive form factors for different currents, as an illustration, and present the results for the vector form factors in detail. Here the solution space emerging is given by the cyclotomic harmonic polylogarithms and their associated special constants. No special basis representation of the master integrals is needed. The algorithm can be applied as well to more general cases factorizing at first order, which are based on more general alphabets, iterated integrals and associated constants.
[ { "created": "Mon, 29 Oct 2018 17:19:43 GMT", "version": "v1" } ]
2018-12-19
[ [ "Ablinger", "J.", "" ], [ "Blümlein", "J.", "" ], [ "Marquard", "P.", "" ], [ "Rana", "N.", "" ], [ "Schneider", "C.", "" ] ]
We present an algorithm which allows to solve analytically linear systems of differential equations which factorize to first order. The solution is given in terms of iterated integrals over an alphabet where its structure is implied by the coefficient matrix of the differential equations. These systems appear in a large variety of higher order calculations in perturbative Quantum Field Theories. We apply this method to calculate the master integrals of the three--loop massive form factors for different currents, as an illustration, and present the results for the vector form factors in detail. Here the solution space emerging is given by the cyclotomic harmonic polylogarithms and their associated special constants. No special basis representation of the master integrals is needed. The algorithm can be applied as well to more general cases factorizing at first order, which are based on more general alphabets, iterated integrals and associated constants.
hep-ph/9707445
null
P.S.Gill and Manmohan Gupta (CAS in Physics, Panjab University, Chandigarh (India))
Fritzsch-Xing mass matrices, $V_{td}$ and CP Violating phase $\delta$
8 LaTeX pages with 1 figure (to be published in PRD as brief Report)
Phys.Rev. D56 (1997) 3143-3146
10.1103/PhysRevD.56.3143
PU-HEP/96/gl04 (P U Chd India)
hep-ph
null
Natural 4 zeros texture mass matrices recently proposed by Fritzsch and Xing have been investigated by including `non-leading'corrections in the context of latest data regarding m_t^{pole} and V_{CKM} matrix elements. Apart from accommodating m_t^{pole} in the range 175\pm15 GeV, |V_{cb}| and |V_{ub}/V_{cb}|=0.08\pm0.02, the analysis with maximal CP-violation predicts |V_{td}| = .005-.013. Further, the CP-violating phase angle \delta can be restricted to the ranges (i) 22^o -45^o and (ii) 95^o - 130^o, concretizing the ambiguity regarding phase of CKM matrix. Furthermore, we find that non-leading calculations are important when `Cabibbo triangle' is to be linked to unitarity triangle.
[ { "created": "Wed, 23 Jul 1997 12:46:10 GMT", "version": "v1" } ]
2009-10-30
[ [ "Gill", "P. S.", "", "CAS in Physics, Panjab University,\n Chandigarh" ], [ "Gupta", "Manmohan", "", "CAS in Physics, Panjab University,\n Chandigarh" ] ]
Natural 4 zeros texture mass matrices recently proposed by Fritzsch and Xing have been investigated by including `non-leading'corrections in the context of latest data regarding m_t^{pole} and V_{CKM} matrix elements. Apart from accommodating m_t^{pole} in the range 175\pm15 GeV, |V_{cb}| and |V_{ub}/V_{cb}|=0.08\pm0.02, the analysis with maximal CP-violation predicts |V_{td}| = .005-.013. Further, the CP-violating phase angle \delta can be restricted to the ranges (i) 22^o -45^o and (ii) 95^o - 130^o, concretizing the ambiguity regarding phase of CKM matrix. Furthermore, we find that non-leading calculations are important when `Cabibbo triangle' is to be linked to unitarity triangle.
2105.14054
Miguel Nebot
Jo\~ao M. Alves (Lisbon, CFTP), Francisco J. Botella (Valencia U., IFIC), Gustavo C. Branco (Lisbon, CFTP), Fernando Cornet-Gomez, Miguel Nebot (Valencia U., IFIC)
The framework for a common origin of $\delta_{\rm CKM}$ and $\delta_{\rm PMNS}$
20 pages
null
10.1140/epjc/s10052-021-09512-y
CFTP/21-08 IFIC/21-17
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse a possible connection between CP violations in the quark and lepton sectors, parametrised by the CKM and PMNS phases. If one assumes that CP breaking arises from complex Yukawa couplings, both in the quark and lepton sectors, the above connection is not possible in general, since Yukawa couplings in the two sectors have independent flavour structures. We show that both the CKM and PMNS phases can instead be generated by a vacuum phase in a class of two Higgs doublet models, and in this case a connection may be established. This scenario requires the presence of scalar FCNC at tree level, both in the quark and lepton sectors. The appearance of these FCNC is an obstacle and a blessing. An obstacle since one has to analyse which models are able to conform to the strict experimental limits on FCNC, both in the quark and lepton sectors. A blessing, because this class of models is falsifiable since FCNC arise at a level which can be probed experimentally in the near future, specially in the processes $h\to e^\pm\tau^\mp$ and $t\to h c$. The connection between CP violations in CKM and PMNS is explicitely illustrated in models with Minimal Flavour Violation.
[ { "created": "Fri, 28 May 2021 18:42:18 GMT", "version": "v1" } ]
2021-09-01
[ [ "Alves", "João M.", "", "Lisbon, CFTP" ], [ "Botella", "Francisco J.", "", "Valencia U.,\n IFIC" ], [ "Branco", "Gustavo C.", "", "Lisbon, CFTP" ], [ "Cornet-Gomez", "Fernando", "", "Valencia U., IFIC" ], [ "Nebot", "Miguel", "", "Valencia U., IFIC" ] ]
We analyse a possible connection between CP violations in the quark and lepton sectors, parametrised by the CKM and PMNS phases. If one assumes that CP breaking arises from complex Yukawa couplings, both in the quark and lepton sectors, the above connection is not possible in general, since Yukawa couplings in the two sectors have independent flavour structures. We show that both the CKM and PMNS phases can instead be generated by a vacuum phase in a class of two Higgs doublet models, and in this case a connection may be established. This scenario requires the presence of scalar FCNC at tree level, both in the quark and lepton sectors. The appearance of these FCNC is an obstacle and a blessing. An obstacle since one has to analyse which models are able to conform to the strict experimental limits on FCNC, both in the quark and lepton sectors. A blessing, because this class of models is falsifiable since FCNC arise at a level which can be probed experimentally in the near future, specially in the processes $h\to e^\pm\tau^\mp$ and $t\to h c$. The connection between CP violations in CKM and PMNS is explicitely illustrated in models with Minimal Flavour Violation.
0807.0801
Gilberto Colangelo
Gilberto Colangelo, Emanuel Nikolidakis and Christopher Smith
Supersymmetric models with minimal flavour violation and their running
plain latex, 38 pages and 5 figures Eq. (12) corrected and one reference added, conclusions unchanged. Published version
Eur.Phys.J.C59:75-98,2009
10.1140/epjc/s10052-008-0796-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the formulation of the principle of minimal flavor violation (MFV) in the minimal supersymmetric extension of the standard model, both at moderate and large tan(beta), and with or without new CP-violating phases. We introduce a counting rule which keeps track of the highly hierarchical structure of the Yukawa matrices. In this manner, we are able to control systematically which terms can be discarded in the soft SUSY breaking part of the Lagrangian. We argue that for the implementation of this counting rule, it is convenient to introduce a new basis of matrices in which both the squark (and slepton) mass terms as well as the trilinear couplings can be expanded. We derive the RGE for the MFV parameters and show that the beta functions also respect the counting rule. For moderate tan(beta), we provide explicit analytic solutions of these RGE and illustrate their behaviour by analyzing the neighbourhood (also switching on new phases) of the SPS-1a benchmark point. We then show that even in the case of large tan(beta), the RGE remain valid and that the analytic solutions obtained for moderate tan(beta) still allow us to understand the most important features of the running of the parameters, as illustrated with the help of the SPS-4 benchmark point.
[ { "created": "Mon, 7 Jul 2008 15:28:52 GMT", "version": "v1" }, { "created": "Wed, 21 Jan 2009 15:06:39 GMT", "version": "v2" } ]
2009-01-21
[ [ "Colangelo", "Gilberto", "" ], [ "Nikolidakis", "Emanuel", "" ], [ "Smith", "Christopher", "" ] ]
We revisit the formulation of the principle of minimal flavor violation (MFV) in the minimal supersymmetric extension of the standard model, both at moderate and large tan(beta), and with or without new CP-violating phases. We introduce a counting rule which keeps track of the highly hierarchical structure of the Yukawa matrices. In this manner, we are able to control systematically which terms can be discarded in the soft SUSY breaking part of the Lagrangian. We argue that for the implementation of this counting rule, it is convenient to introduce a new basis of matrices in which both the squark (and slepton) mass terms as well as the trilinear couplings can be expanded. We derive the RGE for the MFV parameters and show that the beta functions also respect the counting rule. For moderate tan(beta), we provide explicit analytic solutions of these RGE and illustrate their behaviour by analyzing the neighbourhood (also switching on new phases) of the SPS-1a benchmark point. We then show that even in the case of large tan(beta), the RGE remain valid and that the analytic solutions obtained for moderate tan(beta) still allow us to understand the most important features of the running of the parameters, as illustrated with the help of the SPS-4 benchmark point.
hep-ph/9410260
Markus Finkemeier
R. Decker, M. Finkemeier, P. Heiliger and H.H. Jonsson
Tau Decays into Four Pions
12 pages, 12 figures (appended). Revised version: Minor changes in presentation and references. Fortran code included with tex source.
Z.Phys. C70 (1996) 247-254
null
TTP 94-13, LNF-94/066(IR)
hep-ph
null
We compute branching ratios and invariant mass distributions of the tau decays into four pions. The hadronic matrix elements are obtained by starting from the structure of the hadronic current in chiral limit and then implementing low-lying resonances in the different channels. Reasonable agreement with experiment is obtained both for the $\tau \to \nu_{\tau} + (4 \pi ) $ decay rates and the $e^+e^- \to (4 \pi ) $ cross sections. Furthermore we supply an interface to use our matrix elements within the Tauola Monte-Carlo program.
[ { "created": "Tue, 11 Oct 1994 13:53:42 GMT", "version": "v1" }, { "created": "Thu, 11 May 1995 15:02:34 GMT", "version": "v2" } ]
2009-09-25
[ [ "Decker", "R.", "" ], [ "Finkemeier", "M.", "" ], [ "Heiliger", "P.", "" ], [ "Jonsson", "H. H.", "" ] ]
We compute branching ratios and invariant mass distributions of the tau decays into four pions. The hadronic matrix elements are obtained by starting from the structure of the hadronic current in chiral limit and then implementing low-lying resonances in the different channels. Reasonable agreement with experiment is obtained both for the $\tau \to \nu_{\tau} + (4 \pi ) $ decay rates and the $e^+e^- \to (4 \pi ) $ cross sections. Furthermore we supply an interface to use our matrix elements within the Tauola Monte-Carlo program.
1810.12915
Andreas Papaefstathiou
Duff Neill, Andreas Papaefstathiou, Wouter J. Waalewijn, Lorenzo Zoppi
Phenomenology with a recoil-free jet axis: TMD fragmentation and the jet shape
26 pages, 16 figures, version 2: matches Journal version
null
10.1007/JHEP01(2019)067
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the phenomenology of recoil-free jet axes using analytic calculations and Monte Carlo simulations. Our focus is on the average energy as function of the angle with the jet axis (the jet shape), and the energy and transverse momenta of hadrons in a jet (TMD fragmentation). We find that the dependence on the angle (or transverse momentum) is governed by a power law, in contrast to the double-logarithmic dependence for the standard jet axis. The effects of the jet radius, jet algorithm, angular resolution and grooming are investigated. TMD fragmentation is important for constraining the structure of the proton through semi-inclusive deep-inelastic scattering. These observables are also of interest to the LHC, for example to constrain $\alpha_s$ from precision jet measurements, or probe the quark-gluon plasma in heavy-ion collisions.
[ { "created": "Tue, 30 Oct 2018 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 8 Jan 2019 13:55:19 GMT", "version": "v2" } ]
2019-01-30
[ [ "Neill", "Duff", "" ], [ "Papaefstathiou", "Andreas", "" ], [ "Waalewijn", "Wouter J.", "" ], [ "Zoppi", "Lorenzo", "" ] ]
We study the phenomenology of recoil-free jet axes using analytic calculations and Monte Carlo simulations. Our focus is on the average energy as function of the angle with the jet axis (the jet shape), and the energy and transverse momenta of hadrons in a jet (TMD fragmentation). We find that the dependence on the angle (or transverse momentum) is governed by a power law, in contrast to the double-logarithmic dependence for the standard jet axis. The effects of the jet radius, jet algorithm, angular resolution and grooming are investigated. TMD fragmentation is important for constraining the structure of the proton through semi-inclusive deep-inelastic scattering. These observables are also of interest to the LHC, for example to constrain $\alpha_s$ from precision jet measurements, or probe the quark-gluon plasma in heavy-ion collisions.
0710.1401
Vali Bashiry
V. Bashiry, K. Zeynali
Analysis of the B --> \pi \ell^+ \ell^- Decay in the Standard Model with Fourth Generation
17 pages, 8 figures
null
10.1088/1126-6708/2007/12/055
null
hep-ph
null
We investigate the influence of the fourth generation quarks on the branching ratio and the CP-asymmetry in B -->\pi \ell^+ \ell^- decay. Taking the |V_{t'd}V_{t'b}| ~ 0.001 with phase about 10 degree, which is consistent with the sin2\phi_1 of the CKM and the B_d mixing parameter \Delta m_{B_d}, we obtain that for both muon and tau channels the branching ratio, the magnitude of CP-asymmetry and lepton polarization depict strong dependency on the 4th generation quarks mass and mixing parameters. These results can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation quarks($t', b')$ via its indirect manifestations in loop diagrams.
[ { "created": "Sun, 7 Oct 2007 07:27:18 GMT", "version": "v1" }, { "created": "Wed, 10 Oct 2007 11:34:38 GMT", "version": "v2" } ]
2009-11-13
[ [ "Bashiry", "V.", "" ], [ "Zeynali", "K.", "" ] ]
We investigate the influence of the fourth generation quarks on the branching ratio and the CP-asymmetry in B -->\pi \ell^+ \ell^- decay. Taking the |V_{t'd}V_{t'b}| ~ 0.001 with phase about 10 degree, which is consistent with the sin2\phi_1 of the CKM and the B_d mixing parameter \Delta m_{B_d}, we obtain that for both muon and tau channels the branching ratio, the magnitude of CP-asymmetry and lepton polarization depict strong dependency on the 4th generation quarks mass and mixing parameters. These results can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation quarks($t', b')$ via its indirect manifestations in loop diagrams.
hep-ph/0510332
Claudio Coriano
Claudio Coriano', Nikos Irges and Elias Kiritsis
On the Effective Theory of Low Scale Orientifold String Vacua
73 pages, 2 figs (v2) Macro problems fixed, typo corrected
Nucl.Phys. B746 (2006) 77-135
10.1016/j.nuclphysb.2006.04.009
CPHT-RR 063.1005, LTH 678
hep-ph hep-th
null
The effective field theory of the minimal Low Scale Orientifold Models is developed. It describes universal features of related orientifold vacua in string theory. It contains, beyond the Standard Model fields, an MSSM-like Higgs sector and three anomalous (massive) U(1) gauge bosons. All renormalizable couplings are included as well as some dimension-five couplings that are important for anomaly cancellation. The Higgs symmetry breaking induces mixing between the anomalous U(1) gauge bosons and the photon and $Z^0$. This mixing as well as the anomaly generated cubic vector boson couplings is potentially important for discriminating such models from other theories containing Z's. Some interesting tree-level processes are also evaluated.
[ { "created": "Tue, 25 Oct 2005 17:41:30 GMT", "version": "v1" }, { "created": "Tue, 8 Nov 2005 20:37:34 GMT", "version": "v2" } ]
2010-04-05
[ [ "Coriano'", "Claudio", "" ], [ "Irges", "Nikos", "" ], [ "Kiritsis", "Elias", "" ] ]
The effective field theory of the minimal Low Scale Orientifold Models is developed. It describes universal features of related orientifold vacua in string theory. It contains, beyond the Standard Model fields, an MSSM-like Higgs sector and three anomalous (massive) U(1) gauge bosons. All renormalizable couplings are included as well as some dimension-five couplings that are important for anomaly cancellation. The Higgs symmetry breaking induces mixing between the anomalous U(1) gauge bosons and the photon and $Z^0$. This mixing as well as the anomaly generated cubic vector boson couplings is potentially important for discriminating such models from other theories containing Z's. Some interesting tree-level processes are also evaluated.
1106.0998
Andrzej Buras
Andrzej J. Buras
Flavour Visions
18 pages, 1 Figure, Talk given at the 13th International Conference on B-Physics at Hadron Machines, April 4-8 2011 Amsterdam, the Netherlands
null
null
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This decade will allow to improve the resolution of the short distance scales by at least an order of magnitude, extending the picture of fundamental physics down to scales $5\cdot 10^{-20}$m with the help of the LHC. Further resolution down to scales as short as $10^{-21}$m should be possible with the help of high precision experiments in which flavour violating processes will play a prominent role. Will this increase in resolution allow us to see new particles (new animalcula) similarly to what Antoni van Leeuvenhoek saw by discovering bacteria in 1676? The basic question for particle physics is how these new animalcula will look like and which difficulties of the Standard Model (SM) they will help us to solve and which new puzzles and problems they will bring with them. I will describe what role flavour physics will play in these exciting times provided this new world is animalculated.
[ { "created": "Mon, 6 Jun 2011 09:34:56 GMT", "version": "v1" } ]
2011-06-07
[ [ "Buras", "Andrzej J.", "" ] ]
This decade will allow to improve the resolution of the short distance scales by at least an order of magnitude, extending the picture of fundamental physics down to scales $5\cdot 10^{-20}$m with the help of the LHC. Further resolution down to scales as short as $10^{-21}$m should be possible with the help of high precision experiments in which flavour violating processes will play a prominent role. Will this increase in resolution allow us to see new particles (new animalcula) similarly to what Antoni van Leeuvenhoek saw by discovering bacteria in 1676? The basic question for particle physics is how these new animalcula will look like and which difficulties of the Standard Model (SM) they will help us to solve and which new puzzles and problems they will bring with them. I will describe what role flavour physics will play in these exciting times provided this new world is animalculated.
hep-ph/0108152
Taizan Watari
T.Watari and T.Yanagida
Supersymmetric Grand Unification Model with the Orbifold Symmetry Breaking in the Six Dimensional Supergravity
9 pages, including 2 figures, UT-962
Phys.Lett. B519 (2001) 164-168
10.1016/S0370-2693(01)01124-8
null
hep-ph
null
We construct supersymmetric (SUSY) grand unification (GUT) models in the six dimensional space-time where the GUT symmetry is broken down to the standard-model gauge group by a simple orbifolding T^2/Z_4 or T^2/Z_6 and a pair of massless Higgs doublets in the SUSY standard model are naturally obtained. Since the background geometry here is simple compared with models using the Scherk-Schwarz mechanism, one might hope for an approximate gauge coupling unification in the present models. Here, the presence of the massless Higgs multiplets in the bulk is quite natural, since the anomaly cancellation in the six dimensional space-time requires N=2 hyper multiplets in the bulk, some of which are origins of the Higgs doublets. However, the origin of the quarks and leptons is still not clear at all.
[ { "created": "Sun, 19 Aug 2001 13:54:07 GMT", "version": "v1" } ]
2009-11-07
[ [ "Watari", "T.", "" ], [ "Yanagida", "T.", "" ] ]
We construct supersymmetric (SUSY) grand unification (GUT) models in the six dimensional space-time where the GUT symmetry is broken down to the standard-model gauge group by a simple orbifolding T^2/Z_4 or T^2/Z_6 and a pair of massless Higgs doublets in the SUSY standard model are naturally obtained. Since the background geometry here is simple compared with models using the Scherk-Schwarz mechanism, one might hope for an approximate gauge coupling unification in the present models. Here, the presence of the massless Higgs multiplets in the bulk is quite natural, since the anomaly cancellation in the six dimensional space-time requires N=2 hyper multiplets in the bulk, some of which are origins of the Higgs doublets. However, the origin of the quarks and leptons is still not clear at all.
hep-ph/9605440
D. R. T. Jones
P.M. Ferreira, I. Jack and D.R.T. Jones
The three-loop SSM $\beta$-functions
10 pages. Plain Tex. Uses Harvmac and epsf. Three figures. Final journal version, with more accurate boundary conditions, affecting two of the figures
Phys.Lett. B387 (1996) 80-86
10.1016/0370-2693(96)01005-2
LTH 372
hep-ph
null
We present the supersymmetric standard model three-loop $\beta$-functions for gauge and Yukawa couplings and consider the effect of three-loop corrections on the standard running coupling analyses.
[ { "created": "Thu, 30 May 1996 14:11:50 GMT", "version": "v1" }, { "created": "Thu, 13 Jun 1996 16:25:00 GMT", "version": "v2" }, { "created": "Wed, 9 Oct 1996 14:35:04 GMT", "version": "v3" } ]
2009-10-28
[ [ "Ferreira", "P. M.", "" ], [ "Jack", "I.", "" ], [ "Jones", "D. R. T.", "" ] ]
We present the supersymmetric standard model three-loop $\beta$-functions for gauge and Yukawa couplings and consider the effect of three-loop corrections on the standard running coupling analyses.
hep-ph/0210380
Stefan Dittmaier
Stefan Dittmaier
Associated Higgs production with heavy quark pairs at hadron colliders
9 pages, latex, 4 ps files, to appear in the proceedings of "The 10th International Conference on Supersymmetry and Unification of Fundamental Interactions, SUSY02"
null
null
MPI-PhT/2002-62
hep-ph
null
The reactions p\bar{p}/pp -> t\bar{t}H+X represent important channels in the search for the Standard Model Higgs boson at the Tevatron and the LHC. In the leading perturbative order the cross sections suffer from severe (renormalization and factorization) scale uncertainties. The next-to-leading order QCD corrections stabilize the cross sections considerably. The calculation of these corrections is briefly reviewed, and a few numerical results are discussed.
[ { "created": "Mon, 28 Oct 2002 14:44:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dittmaier", "Stefan", "" ] ]
The reactions p\bar{p}/pp -> t\bar{t}H+X represent important channels in the search for the Standard Model Higgs boson at the Tevatron and the LHC. In the leading perturbative order the cross sections suffer from severe (renormalization and factorization) scale uncertainties. The next-to-leading order QCD corrections stabilize the cross sections considerably. The calculation of these corrections is briefly reviewed, and a few numerical results are discussed.
0804.2503
Haibo Yu
Mu-Chun Chen and Hai-Bo Yu
Minimal Flavor Violation in the Lepton Sector of the Randall-Sundrum Model
12 pages, no figure; v2: clarifying remarks and references added; v3: version to appear in Phys. Lett. B
Phys.Lett.B672:253-256,2009
10.1016/j.physletb.2009.01.030
UCI-TR-2008-16, NSF-KITP-08-57
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a realization of Minimal Flavor Violation in the lepton sector of the Randall-Sundrum model. With the MFV assumption, the only source of flavor violation are the 5D Yukawa couplings, and the usual two independent sources of flavor violation are related. In the limit of massless neutrinos, the bulk mass matrices and 5D Yukawa matrices are simultaneously diagonalized, and hence the absence of FCNCs. In the case of massive neutrinos, the contributions to FCNCs in the charged lepton sector are highly suppressed, due to the smallness of neutrino masses. In addition, the MFV assumption also allows suppressing one-loop charged current contributions to flavor changing processes by reducing the size of the Yukawa couplings, which is not possible in the generic anarchical case. We found that the first KK mass scale as low as ~ 3 TeV can be allowed. In both cases, we present a set of numerical results that give rise to realistic lepton masses and mixing angles. Mild hierarchy in the 5D Yukawa matrix of O(25) in our numerical example is required to be consistent with two large and one small mixing angles. This tuning could be improved by having a more thorough search of the parameter space.
[ { "created": "Wed, 16 Apr 2008 17:59:30 GMT", "version": "v1" }, { "created": "Tue, 1 Jul 2008 20:35:40 GMT", "version": "v2" }, { "created": "Wed, 28 Jan 2009 08:26:04 GMT", "version": "v3" } ]
2009-02-18
[ [ "Chen", "Mu-Chun", "" ], [ "Yu", "Hai-Bo", "" ] ]
We propose a realization of Minimal Flavor Violation in the lepton sector of the Randall-Sundrum model. With the MFV assumption, the only source of flavor violation are the 5D Yukawa couplings, and the usual two independent sources of flavor violation are related. In the limit of massless neutrinos, the bulk mass matrices and 5D Yukawa matrices are simultaneously diagonalized, and hence the absence of FCNCs. In the case of massive neutrinos, the contributions to FCNCs in the charged lepton sector are highly suppressed, due to the smallness of neutrino masses. In addition, the MFV assumption also allows suppressing one-loop charged current contributions to flavor changing processes by reducing the size of the Yukawa couplings, which is not possible in the generic anarchical case. We found that the first KK mass scale as low as ~ 3 TeV can be allowed. In both cases, we present a set of numerical results that give rise to realistic lepton masses and mixing angles. Mild hierarchy in the 5D Yukawa matrix of O(25) in our numerical example is required to be consistent with two large and one small mixing angles. This tuning could be improved by having a more thorough search of the parameter space.
hep-ph/9511382
Goloskokov Sergei Vitalievich
S.V.Goloskokov
Structure of Pomeron Couplings and Single-Spin Asymmetry in Diffractive $Q \bar Q$ Production
7 pages, latex, 5 figures in compressed uufile
Phys.Rev.D53:5995-5999,1996
10.1103/PhysRevD.53.5995
IFUP-TH 66/95
hep-ph
null
Transverse single spin asymmetry in polarized diffractive $Q \bar Q$ production is calculated. It is shown that this asymmetry depends strongly on the spin structure of the pomeron coupling, which permits one to study the pomeron couplings properties in future polarized experiments.
[ { "created": "Tue, 21 Nov 1995 13:35:02 GMT", "version": "v1" } ]
2010-01-06
[ [ "Goloskokov", "S. V.", "" ] ]
Transverse single spin asymmetry in polarized diffractive $Q \bar Q$ production is calculated. It is shown that this asymmetry depends strongly on the spin structure of the pomeron coupling, which permits one to study the pomeron couplings properties in future polarized experiments.
hep-ph/9402337
G. Ecker
G. Ecker
Chiral invariant renormalization of the pion--nucleon interaction
13 pages, LaTex, 2 figures in appended postscript file, Univ. Wien preprint UWThPh-1994-1
Phys.Lett. B336 (1994) 508-517
10.1016/0370-2693(94)90565-7
null
hep-ph nucl-th
null
The leading divergences of the generating functional for Green functions of quark currents between one--nucleon states are calculated with heat kernel techniques. The results allow for a chiral invariant renormalization of all two--nucleon Green functions of the pion--nucleon system to $O(p^3)$ in the low--energy expansion.
[ { "created": "Tue, 22 Feb 1994 13:04:15 GMT", "version": "v1" } ]
2009-10-28
[ [ "Ecker", "G.", "" ] ]
The leading divergences of the generating functional for Green functions of quark currents between one--nucleon states are calculated with heat kernel techniques. The results allow for a chiral invariant renormalization of all two--nucleon Green functions of the pion--nucleon system to $O(p^3)$ in the low--energy expansion.
hep-ph/9309238
Daniel Boyanovsky
D. Boyanovsky, H. J. de Vega and R. Holman
Dynamics of Cosmological Phase Transitions
26 pages;Latex;4 figures not included, available upon request; PITT-93-9
null
null
null
hep-ph
null
The dynamics of typical phase transitions is studied out of equilibrium in weakly coupled inflaton-type scalar field theories in Minkowski space. The shortcomings of the effective potential and equilibrium descriptions are pointed out. A case of a rapid supercooling from $T_i>T_c$ to $T_f \ll T_c$ is considered. The equations of motion up to one-loop for the order parameter are obtained and integrated for the case of ``slow rollover initial conditions''. It is shown that the instabilities responsible for the process of phase separation introduce dramatic corrections to the evolution. Domain formation and growth (spinodal decomposition) is studied in a non-perturbative self-consistent approximation. For very weakly coupled theories domains grow for a long time, their final size is several times the zero temperature correlation length. For strongly coupled theories the final size of the domains is comparable to the zero temperature correlation length and the transition proceeds faster. We also obtain the evolution equations for the order parameter and the fluctuations to one-loop order and in a non-perturbative Hartree approximation in spatially flat FRW cosmologies. The renormalization, and leading behavior of the high temperature limit are analyzed.
[ { "created": "Tue, 7 Sep 1993 20:20:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Boyanovsky", "D.", "" ], [ "de Vega", "H. J.", "" ], [ "Holman", "R.", "" ] ]
The dynamics of typical phase transitions is studied out of equilibrium in weakly coupled inflaton-type scalar field theories in Minkowski space. The shortcomings of the effective potential and equilibrium descriptions are pointed out. A case of a rapid supercooling from $T_i>T_c$ to $T_f \ll T_c$ is considered. The equations of motion up to one-loop for the order parameter are obtained and integrated for the case of ``slow rollover initial conditions''. It is shown that the instabilities responsible for the process of phase separation introduce dramatic corrections to the evolution. Domain formation and growth (spinodal decomposition) is studied in a non-perturbative self-consistent approximation. For very weakly coupled theories domains grow for a long time, their final size is several times the zero temperature correlation length. For strongly coupled theories the final size of the domains is comparable to the zero temperature correlation length and the transition proceeds faster. We also obtain the evolution equations for the order parameter and the fluctuations to one-loop order and in a non-perturbative Hartree approximation in spatially flat FRW cosmologies. The renormalization, and leading behavior of the high temperature limit are analyzed.
hep-ph/0304140
Sergey Afonin
V.A. Andrianov and S.S. Afonin
Vector particles in Quasilocal Quark Models
18 pages
Zap.Nauchn.Semin. 291 (2002) 5
null
null
hep-ph
null
We consider the Quasilocal Quark Model of NJL type including vector and axial-vector four-fermion interaction with derivatives. The mass spectrum for the ground and first excited states is obtained. The chiral symmetry restoration sum rules in these channels are imposed as matching rules to QCD at intermediate energies and a set of constraints on parameters of QQM is performed.
[ { "created": "Tue, 15 Apr 2003 10:35:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Andrianov", "V. A.", "" ], [ "Afonin", "S. S.", "" ] ]
We consider the Quasilocal Quark Model of NJL type including vector and axial-vector four-fermion interaction with derivatives. The mass spectrum for the ground and first excited states is obtained. The chiral symmetry restoration sum rules in these channels are imposed as matching rules to QCD at intermediate energies and a set of constraints on parameters of QQM is performed.
hep-ph/0612161
Rasmus Mackeprang
Rasmus Mackeprang, Andrea Rizzi
Interactions of Coloured Heavy Stable Particles in Matter
null
Eur.Phys.J.C50:353-362,2007
10.1140/epjc/s10052-007-0252-4
null
hep-ph
null
In this paper we present a physics model for the interactions of stable heavy hadrons containing a heavy parton with matter. The model presented is a natural continuation of the work started in hep-ex/0404001. However, changes and generalisations have been made allowing for the description of a broader scope of physics scenarios. As a special case the model is tested on the cases of stable gluino and stop hadrons, thus covering both stable colour triplet and octet states. Conclusions are drawn regarding the phenomenology of these cases including how to distinguish between them.
[ { "created": "Wed, 13 Dec 2006 11:14:11 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mackeprang", "Rasmus", "" ], [ "Rizzi", "Andrea", "" ] ]
In this paper we present a physics model for the interactions of stable heavy hadrons containing a heavy parton with matter. The model presented is a natural continuation of the work started in hep-ex/0404001. However, changes and generalisations have been made allowing for the description of a broader scope of physics scenarios. As a special case the model is tested on the cases of stable gluino and stop hadrons, thus covering both stable colour triplet and octet states. Conclusions are drawn regarding the phenomenology of these cases including how to distinguish between them.
hep-ph/0309129
Yasutaka Takanishi
C. D. Froggatt, L. V. Laperashvili, H. B. Nielsen, Y. Takanishi
Family Replicated Gauge Group Models
7 pages, 2 figures, Latex2e, Talk given by L. V. Laperashvili at the Fifth International Conference ``Symmetry in Nonlinear Mathematical Physics'', Kyiv, Ukraine, June 23-29, 2003
EconfC0306234:737-743,2003
null
null
hep-ph
null
Family Replicated Gauge Group models of the type SU(n)^N\times SU(m)^N, (SMG)^3 and (SMG\times U(1)_{B-L})^3 are reviewed, where SMG=SU(3)_{c}\times SU(2)_{L}\times U(1)_{Y} is the gauge symmetry group of the Standard Model, $B$ is the baryon and $L$ is the lepton numbers, respectively. It was shown that Family Replicated Gauge Group model of the latter type fits the Standard Model fermion masses and mixing angles and describes all neutrino experiment data order magnitudewise using only 5 free parameters -- five vacuum expectation values of the Higgs fields which break the Family Replicated Gauge Group symmetry to the Standard Model. The possibility of [SU(5)]^3 or [SO(10)]^3 unification at the GUT-scale \sim 10^{18} GeV also is briefly considered.
[ { "created": "Thu, 11 Sep 2003 17:38:59 GMT", "version": "v1" } ]
2008-11-26
[ [ "Froggatt", "C. D.", "" ], [ "Laperashvili", "L. V.", "" ], [ "Nielsen", "H. B.", "" ], [ "Takanishi", "Y.", "" ] ]
Family Replicated Gauge Group models of the type SU(n)^N\times SU(m)^N, (SMG)^3 and (SMG\times U(1)_{B-L})^3 are reviewed, where SMG=SU(3)_{c}\times SU(2)_{L}\times U(1)_{Y} is the gauge symmetry group of the Standard Model, $B$ is the baryon and $L$ is the lepton numbers, respectively. It was shown that Family Replicated Gauge Group model of the latter type fits the Standard Model fermion masses and mixing angles and describes all neutrino experiment data order magnitudewise using only 5 free parameters -- five vacuum expectation values of the Higgs fields which break the Family Replicated Gauge Group symmetry to the Standard Model. The possibility of [SU(5)]^3 or [SO(10)]^3 unification at the GUT-scale \sim 10^{18} GeV also is briefly considered.
1605.00575
Eduardo Rojas
Oscar Rodr\'iguez, Richard H. Benavides, William A. Ponce, Eduardo Rojas
Flipped versions of the universal 3-3-1 and the left-right symmetric models in $[SU(3)]^3$: a comprehensive approach
null
Phys. Rev. D 95, 014009 (2017)
10.1103/PhysRevD.95.014009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By considering the 3-3-1 and the left-right symmetric models as low energy effective theories of the $SU(3)_C\otimes SU(3)_L\otimes SU(3)_R$~(for short $[SU(3)]^3$) gauge group, alternative versions of these models are found. The new neutral gauge bosons of the universal 3-3-1 model and its flipped versions are presented; also, the left-right symmetric model and its flipped variants are studied. Our analysis shows that there are two flipped versions of the universal 3-3-1 model, with the particularity that both of them have the same weak charges. For the left-right symmetric model we also found two flipped versions; one of them new in the literature which, unlike those of the 3-3-1, requires a dedicated study of its electroweak properties. For all the models analyzed, the couplings of the $Z'$ bosons to the standard model fermions are reported. The explicit form of the null space of the vector boson mass matrix for an arbitrary Higgs tensor and gauge group is also presented. In the general framework of the $[SU(3)]^3$ gauge group, and by using the LHC experimental results and EW precision data, limits on the $Z'$ mass and the mixing angle between $Z$ and the new gauge bosons $Z'$ are obtained. The general results call for very small mixing angles in the range $10^{-3}$ radians and $M_{Z'}>$ 2.5 TeV.
[ { "created": "Mon, 2 May 2016 17:30:57 GMT", "version": "v1" }, { "created": "Thu, 24 Nov 2016 00:53:10 GMT", "version": "v2" } ]
2017-01-18
[ [ "Rodríguez", "Oscar", "" ], [ "Benavides", "Richard H.", "" ], [ "Ponce", "William A.", "" ], [ "Rojas", "Eduardo", "" ] ]
By considering the 3-3-1 and the left-right symmetric models as low energy effective theories of the $SU(3)_C\otimes SU(3)_L\otimes SU(3)_R$~(for short $[SU(3)]^3$) gauge group, alternative versions of these models are found. The new neutral gauge bosons of the universal 3-3-1 model and its flipped versions are presented; also, the left-right symmetric model and its flipped variants are studied. Our analysis shows that there are two flipped versions of the universal 3-3-1 model, with the particularity that both of them have the same weak charges. For the left-right symmetric model we also found two flipped versions; one of them new in the literature which, unlike those of the 3-3-1, requires a dedicated study of its electroweak properties. For all the models analyzed, the couplings of the $Z'$ bosons to the standard model fermions are reported. The explicit form of the null space of the vector boson mass matrix for an arbitrary Higgs tensor and gauge group is also presented. In the general framework of the $[SU(3)]^3$ gauge group, and by using the LHC experimental results and EW precision data, limits on the $Z'$ mass and the mixing angle between $Z$ and the new gauge bosons $Z'$ are obtained. The general results call for very small mixing angles in the range $10^{-3}$ radians and $M_{Z'}>$ 2.5 TeV.
1903.00063
Abdel Nasser Tawfik
Abdel Nasser Tawfik (Nile U., ECTP & WLCAPP, Cairo), Igor Mishustin (Frankfurt U., FIAS & Kurchatov Inst., Moscow)
Equation of State for Cosmological Matter at and beyond QCD and Electroweak Eras
17 pages, 4 figures, submitted to PRD
J. Phys. G: Nucl. Part. Phys. 46, 125201 (2019)
10.1088/1361-6471/ab46d4
ECTP-2019-02, WLCAPP-2019-02
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Various thermodynamic quantities for baryon-free matter are calculated by combining the most reliable non-perturbative and perturbative calculations, especially the most recent ones including as many quark flavors as possible. We extend these calculations by including other degrees of freedom (dof), such as photons, neutrinos, leptons, electroweak particles, and Higgs bosons, that allows us to consider the temperatures up to the TeV-scale. The calculations show that similar to QCD, the EW phase transition is also a crossover. We have found that while the equation of state for the hadronic matter is linear, $p/\rho\simeq 0.2$, the one for higher temperatures is rather complex; it exhibits two crossover-type phase transitions, corresponding to strong and EW matter. At even larger energy densities, the deduced EoS becomes linear again and close to ideal gas. The combined equation of state can be used for modeling the expansion of the Universe from very early times and through the EW and QCD era.
[ { "created": "Thu, 28 Feb 2019 20:41:24 GMT", "version": "v1" } ]
2019-11-05
[ [ "Tawfik", "Abdel Nasser", "", "Nile U., ECTP & WLCAPP, Cairo" ], [ "Mishustin", "Igor", "", "Frankfurt U., FIAS & Kurchatov Inst., Moscow" ] ]
Various thermodynamic quantities for baryon-free matter are calculated by combining the most reliable non-perturbative and perturbative calculations, especially the most recent ones including as many quark flavors as possible. We extend these calculations by including other degrees of freedom (dof), such as photons, neutrinos, leptons, electroweak particles, and Higgs bosons, that allows us to consider the temperatures up to the TeV-scale. The calculations show that similar to QCD, the EW phase transition is also a crossover. We have found that while the equation of state for the hadronic matter is linear, $p/\rho\simeq 0.2$, the one for higher temperatures is rather complex; it exhibits two crossover-type phase transitions, corresponding to strong and EW matter. At even larger energy densities, the deduced EoS becomes linear again and close to ideal gas. The combined equation of state can be used for modeling the expansion of the Universe from very early times and through the EW and QCD era.
1206.5537
Bjorn Garbrecht
Marco Drewes and Bjorn Garbrecht
Leptogenesis from a GeV Seesaw without Mass Degeneracy
23 pages
null
10.1007/JHEP03(2013)096
TTK-12-28
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For Leptogenesis based on the type-I seesaw mechanism, we present a systematic calculation of lepton-number violating and purely flavoured asymmetries within nonequilibrium Quantum Field Theory. We show that sterile neutrinos with non-degenerate masses in the GeV range can explain the baryon asymmetry of the Universe via flavoured Leptogenesis. This is possible due to the interplay of thermal and flavour effects. Our approach clarifies the relation between Leptogenesis from the oscillations of sterile neutrinos and the more commonly studied scenarios from decays and inverse decays. We explain why lower mass bounds for non-degenerate sterile neutrinos derived for Leptogenesis from out-of-equilibrium decays do not apply to flavoured Leptogenesis with GeV-scale neutrinos.
[ { "created": "Sun, 24 Jun 2012 20:22:46 GMT", "version": "v1" } ]
2015-06-05
[ [ "Drewes", "Marco", "" ], [ "Garbrecht", "Bjorn", "" ] ]
For Leptogenesis based on the type-I seesaw mechanism, we present a systematic calculation of lepton-number violating and purely flavoured asymmetries within nonequilibrium Quantum Field Theory. We show that sterile neutrinos with non-degenerate masses in the GeV range can explain the baryon asymmetry of the Universe via flavoured Leptogenesis. This is possible due to the interplay of thermal and flavour effects. Our approach clarifies the relation between Leptogenesis from the oscillations of sterile neutrinos and the more commonly studied scenarios from decays and inverse decays. We explain why lower mass bounds for non-degenerate sterile neutrinos derived for Leptogenesis from out-of-equilibrium decays do not apply to flavoured Leptogenesis with GeV-scale neutrinos.
hep-ph/0506300
Bo-Qiang Ma
Puze Gao, Bo-Qiang Ma
Probing nucleon strange asymmetry from charm production in neutrino deep inelastic scattering
6 Latex pages, no figure, final version to appear in EPJC
Eur.Phys.J.C44:63-68,2005
10.1140/epjc/s2005-02335-5
null
hep-ph hep-ex nucl-ex nucl-th
null
We propose a means to detect the nucleon strange quark-antiquark asymmetry, which is predicted as a non-perturbative effect, but still unchecked directly by available experiments. The difference for the $D(c\bar{q})$ and $\bar{D}(\bar{c}q)$ meson production cross sections in neutrino and antineutrino induced charged current deep inelastic scattering is illustrated to be sensitive to the nucleon strange asymmetry. Prospect is given and the effect due to the light quark fragmentation is also discussed for the extraction of the strange asymmetry in future experiments.
[ { "created": "Tue, 28 Jun 2005 23:04:53 GMT", "version": "v1" }, { "created": "Fri, 15 Jul 2005 04:13:49 GMT", "version": "v2" } ]
2009-01-07
[ [ "Gao", "Puze", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We propose a means to detect the nucleon strange quark-antiquark asymmetry, which is predicted as a non-perturbative effect, but still unchecked directly by available experiments. The difference for the $D(c\bar{q})$ and $\bar{D}(\bar{c}q)$ meson production cross sections in neutrino and antineutrino induced charged current deep inelastic scattering is illustrated to be sensitive to the nucleon strange asymmetry. Prospect is given and the effect due to the light quark fragmentation is also discussed for the extraction of the strange asymmetry in future experiments.
2205.04477
Bruno Scheihing Hitschfeld
Bruno Scheihing-Hitschfeld and Xiaojun Yao
Gauge Invariance of Non-Abelian Field Strength Correlators: the Axial Gauge Puzzle
16 pages, 2 figures; v2: published version
Phys.Rev.Lett. 130 (2023) 5, 052302
10.1103/PhysRevLett.130.052302
MIT-CTP/5425, IQuS@UW-21-040
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many transport coefficients of the quark-gluon plasma and nuclear structure functions can be written as gauge invariant correlation functions of non-Abelian field strengths dressed with Wilson lines. We discuss the applicability of axial gauge $n\cdot A=0$ to calculate them. In particular, we address issues that appear when one attempts to trivialize the Wilson lines in the correlation functions by gauge-fixing. We find it is always impossible to completely remove the gauge fields $n\cdot A$ in Wilson lines that extend to infinity in the $n$-direction by means of gauge transformations. We show how the obstruction appears in an explicit example of a perturbative calculation, and we also explain it more generally from the perspective of the path integral that defines the theory. Our results explain why the two correlators that define the heavy quark and quarkonium transport coefficients, which are seemingly equal in axial gauge, are actually different physical quantities of the quark-gluon plasma and have different values. Furthermore, our findings provide insights into the difference between two inequivalent gluon parton distribution functions.
[ { "created": "Mon, 9 May 2022 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 7 Feb 2023 21:28:33 GMT", "version": "v2" } ]
2023-02-09
[ [ "Scheihing-Hitschfeld", "Bruno", "" ], [ "Yao", "Xiaojun", "" ] ]
Many transport coefficients of the quark-gluon plasma and nuclear structure functions can be written as gauge invariant correlation functions of non-Abelian field strengths dressed with Wilson lines. We discuss the applicability of axial gauge $n\cdot A=0$ to calculate them. In particular, we address issues that appear when one attempts to trivialize the Wilson lines in the correlation functions by gauge-fixing. We find it is always impossible to completely remove the gauge fields $n\cdot A$ in Wilson lines that extend to infinity in the $n$-direction by means of gauge transformations. We show how the obstruction appears in an explicit example of a perturbative calculation, and we also explain it more generally from the perspective of the path integral that defines the theory. Our results explain why the two correlators that define the heavy quark and quarkonium transport coefficients, which are seemingly equal in axial gauge, are actually different physical quantities of the quark-gluon plasma and have different values. Furthermore, our findings provide insights into the difference between two inequivalent gluon parton distribution functions.
1912.07550
Alessandro Bacchetta
Alessandro Bacchetta, Valerio Bertone, Chiara Bissolotti, Giuseppe Bozzi, Filippo Delcarro, Fulvio Piacenza, Marco Radici
Transverse-momentum-dependent parton distributions up to N$^3$LL from Drell-Yan data
Latest version: added panels in Fig. 4, added chi2 values in Fig. 8, changes in App. C, extended discussion on comparison with ATLAS data (Sec. 4.1), footnote 5 added, other small changes in the text
null
10.1007/JHEP07(2020)117
JLAB-THY-19-3121
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an extraction of unpolarised Transverse-Momentum-Dependent Parton Distribution Functions based on Drell-Yan production data from different experiments, including those at the LHC, and spanning a wide kinematic range. We deal with experimental uncertainties by properly taking into account correlations. We include resummation of logarithms of the transverse momentum of the vector boson up to N$^3$LL order, and we include non-perturbative contributions. These ingredients allow us to obtain a remarkable agreement with the data.
[ { "created": "Mon, 16 Dec 2019 17:56:28 GMT", "version": "v1" }, { "created": "Mon, 23 Dec 2019 22:47:51 GMT", "version": "v2" }, { "created": "Fri, 19 Jun 2020 08:38:52 GMT", "version": "v3" } ]
2020-08-26
[ [ "Bacchetta", "Alessandro", "" ], [ "Bertone", "Valerio", "" ], [ "Bissolotti", "Chiara", "" ], [ "Bozzi", "Giuseppe", "" ], [ "Delcarro", "Filippo", "" ], [ "Piacenza", "Fulvio", "" ], [ "Radici", "Marco", "" ] ]
We present an extraction of unpolarised Transverse-Momentum-Dependent Parton Distribution Functions based on Drell-Yan production data from different experiments, including those at the LHC, and spanning a wide kinematic range. We deal with experimental uncertainties by properly taking into account correlations. We include resummation of logarithms of the transverse momentum of the vector boson up to N$^3$LL order, and we include non-perturbative contributions. These ingredients allow us to obtain a remarkable agreement with the data.
hep-ph/0102239
Mikhail Voloshin
M.B. Voloshin
Once again on electromagnetic properties of a domain wall interacting with charged fermions
15 pages
Phys.Rev. D63 (2001) 125012
10.1103/PhysRevD.63.125012
TPI-MINN-01/10-T, UMN-TH-1942-01
hep-ph hep-th
null
The response to a magnetic flux is considered of the vacuum state of charged Dirac fermions interacting with a domain wall made of a neutral spinless field in (3+1) dimensions with the fermion mass having a phase variation across the wall. It is pointed out that due to simple C parity arguments the spontaneous magnetization for this system is necessarily zero, thus invalidating some claims to the contrary in the literature. The cancellation of the spontaneous magnetization is explicitly demonstrated in a particular class of models. The same calculation produces a general formula for the electric charge density induced by the magnetic flux -- an effect previously discussed in the literature for axionic domain walls. The distribution of the induced charge is calculated in specific models.
[ { "created": "Mon, 19 Feb 2001 20:11:23 GMT", "version": "v1" } ]
2009-11-07
[ [ "Voloshin", "M. B.", "" ] ]
The response to a magnetic flux is considered of the vacuum state of charged Dirac fermions interacting with a domain wall made of a neutral spinless field in (3+1) dimensions with the fermion mass having a phase variation across the wall. It is pointed out that due to simple C parity arguments the spontaneous magnetization for this system is necessarily zero, thus invalidating some claims to the contrary in the literature. The cancellation of the spontaneous magnetization is explicitly demonstrated in a particular class of models. The same calculation produces a general formula for the electric charge density induced by the magnetic flux -- an effect previously discussed in the literature for axionic domain walls. The distribution of the induced charge is calculated in specific models.
1106.0193
Su-Zhi Wu
Yu-Qi Chen and Su-Zhi Wu
Production of Triply Heavy Baryons at LHC
32 pages, 7 figures, to appear in JHEP
null
10.1007/JHEP08(2011)144
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Triply heavy baryons are very interesting hadrons to be explored for they provide particular information about strong interactions, hadron structures, and weak decays of heavy baryons. We calculate the hadronic production cross sections of the \Omega_{ccc} and the \Omega_{ccb}, which are dominated by the gg fusion subprocesses containing 4362 and 1454 Feynman diagrams, respectively. A method for generating and calculating tree level Feynman diagrams automatically is developed to deal with complicated processes containing so many diagrams. Our results show that 10^4-10^5 events of triply heavy baryons can be accumulated for 10 fb^{-1} integrated luminosity at LHC. Signatures of the triply heavy baryons are pointed out, with emphasis on the decay modes \Omega_{ccc} -> \Omega_{sss} + 3 \pi^+ and \Omega_{ccb} -> \Omega_{sss} + 3 \pi^+ +\pi^-. We conclude that it is quite promising to discover them at LHC.
[ { "created": "Wed, 1 Jun 2011 14:43:41 GMT", "version": "v1" }, { "created": "Thu, 2 Jun 2011 14:54:30 GMT", "version": "v2" }, { "created": "Fri, 24 Jun 2011 10:50:30 GMT", "version": "v3" }, { "created": "Tue, 30 Aug 2011 10:01:37 GMT", "version": "v4" } ]
2015-05-28
[ [ "Chen", "Yu-Qi", "" ], [ "Wu", "Su-Zhi", "" ] ]
Triply heavy baryons are very interesting hadrons to be explored for they provide particular information about strong interactions, hadron structures, and weak decays of heavy baryons. We calculate the hadronic production cross sections of the \Omega_{ccc} and the \Omega_{ccb}, which are dominated by the gg fusion subprocesses containing 4362 and 1454 Feynman diagrams, respectively. A method for generating and calculating tree level Feynman diagrams automatically is developed to deal with complicated processes containing so many diagrams. Our results show that 10^4-10^5 events of triply heavy baryons can be accumulated for 10 fb^{-1} integrated luminosity at LHC. Signatures of the triply heavy baryons are pointed out, with emphasis on the decay modes \Omega_{ccc} -> \Omega_{sss} + 3 \pi^+ and \Omega_{ccb} -> \Omega_{sss} + 3 \pi^+ +\pi^-. We conclude that it is quite promising to discover them at LHC.
hep-ph/9307232
Wai-Yee
Darwin Chang, Wai-Yee Keung, and Ivan Phillips
CP Violating Observables in $e^-e^+ \to W^-W^+$
23 pages, plus 11 postscript graphs not posted before
Phys.Rev.D48:4045-4061,1993
10.1103/PhysRevD.48.4045
CERN-TH.6839/93
hep-ph
null
We consider various integrated lepton charge-energy asymmetries and azimuthal asymmetries as tests of CP violation in the process $e^-e^+ \to W^-W^+$. These asymmetries are sensitive to different linear combinations of the CP violating form factors in the three gauge boson $W^-W^+$ production vertex, and can distinguish dispersive and absorptive parts of the form factors. It makes use of purely hadronic and purely leptonic modes of $W$'s decays as well as the mixed modes. The techniques of using the kinematics of jets or missing momentum to construct CP--odd observables are also employed. These CP violating observables are illustrated in the generalized Left-Right Model and the Charged Higgs Model.
[ { "created": "Thu, 8 Jul 1993 09:18:04 GMT", "version": "v1" }, { "created": "Tue, 16 Jun 1998 04:33:14 GMT", "version": "v2" } ]
2009-09-01
[ [ "Chang", "Darwin", "" ], [ "Keung", "Wai-Yee", "" ], [ "Phillips", "Ivan", "" ] ]
We consider various integrated lepton charge-energy asymmetries and azimuthal asymmetries as tests of CP violation in the process $e^-e^+ \to W^-W^+$. These asymmetries are sensitive to different linear combinations of the CP violating form factors in the three gauge boson $W^-W^+$ production vertex, and can distinguish dispersive and absorptive parts of the form factors. It makes use of purely hadronic and purely leptonic modes of $W$'s decays as well as the mixed modes. The techniques of using the kinematics of jets or missing momentum to construct CP--odd observables are also employed. These CP violating observables are illustrated in the generalized Left-Right Model and the Charged Higgs Model.
hep-ph/0602064
Yuichiro Kiyo
Y. Kiyo
Third order Coulomb correction to ttbar threshold cross section
To appear in the proceedings of the 7th International Symposium on Radiative Corrections(RADCOR05), Shonan Village, Japana Oct. 2005
Nucl.Phys.Proc.Suppl.157:221-225,2006
10.1016/j.nuclphysbps.2006.03.051
PITHA 06/03
hep-ph
null
We report on our result of third order Coulomb correction to the cross section sigma(ee -> ttbar) near threshold. Analytic expression for the Coulomb energy and wave function at the origin are obtained. We discuss the significance of the Coulomb correction to the threshold cross section and heavy quarkonium phenomenology.
[ { "created": "Tue, 7 Feb 2006 16:14:48 GMT", "version": "v1" } ]
2011-06-24
[ [ "Kiyo", "Y.", "" ] ]
We report on our result of third order Coulomb correction to the cross section sigma(ee -> ttbar) near threshold. Analytic expression for the Coulomb energy and wave function at the origin are obtained. We discuss the significance of the Coulomb correction to the threshold cross section and heavy quarkonium phenomenology.
hep-ph/9302302
Geert Jan van Oldenborgh
Frank Cuypers, Geert Jan van Oldenborgh and Reinhold R\"uckl
Supersymmetric Signals in $\gamma\gamma$ Collisions
12 pages + 6 pages figures (included as uufile, also with anon. ftp from gluon.hep.physik.uni-muenchen.de (129.187.198.1)), LaTeX (axodraw,epsf), CERN-TH.6742/92, MPI-Ph/92-73, LMU-92/07. (forgot the bibliography file - my excuses)
Nucl.Phys. B409 (1993) 144-160
10.1016/0550-3213(93)90450-4
null
hep-ph
null
We study the occurrence of final states with only an electron-positron pair and missing transverse momentum as a signal of \susy\ in photon-photon collisions. Suitable high energy photon beams may be provided at linear colliders by back-scattering laser beams on electron beams. The final states considered represent a typical signature for the production and decay of selctron and chargino pairs within the \mssm. We show that, away from the kinematical threshold, selctrons produce this signal far more abundantly than charginos. The standard model background is dominated by W-pair production. We propose a series of kinematical cuts which reduce this background to an acceptable level. With a 1 TeV collider operated in the $\gamma\gamma$-mode, we find that interesting and complementary tests of \susic\ models can be performed for selctron masses up to 350 GeV.
[ { "created": "Wed, 24 Feb 1993 15:54:08 GMT", "version": "v1" }, { "created": "Thu, 25 Feb 1993 07:43:45 GMT", "version": "v2" }, { "created": "Fri, 26 Feb 1993 09:00:01 GMT", "version": "v3" } ]
2009-10-22
[ [ "Cuypers", "Frank", "" ], [ "van Oldenborgh", "Geert Jan", "" ], [ "Rückl", "Reinhold", "" ] ]
We study the occurrence of final states with only an electron-positron pair and missing transverse momentum as a signal of \susy\ in photon-photon collisions. Suitable high energy photon beams may be provided at linear colliders by back-scattering laser beams on electron beams. The final states considered represent a typical signature for the production and decay of selctron and chargino pairs within the \mssm. We show that, away from the kinematical threshold, selctrons produce this signal far more abundantly than charginos. The standard model background is dominated by W-pair production. We propose a series of kinematical cuts which reduce this background to an acceptable level. With a 1 TeV collider operated in the $\gamma\gamma$-mode, we find that interesting and complementary tests of \susic\ models can be performed for selctron masses up to 350 GeV.
1206.5447
Rashidul Islam
Mamta Dahiya, Sukanta Dutta, Rashidul Islam
Constraining Unparticles from Top Physics at TeVatron
37 pages, 24 figures, 1 new figure and some discussions added, references updated, to appear in Physical Review D
null
10.1103/PhysRevD.86.115022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study and analyze the recent observations of the top pair production $\sigma (p\bar p\to t \bar t)$ at TeVatron through flavor conserving and flavor violating channels ${\it via}$ vector and tensor unparticles. The unparticle sector is considered with the possibility of being a color singlet or octet. The modified unparticle propagator is used to investigate the contribution of these unparticles to the observed $A_{FB}^{t\bar t}$ (forward backward asymmetry in top pair production) and the spin correlation at TeVatron. We have also studied the impact of the flavor violating couplings of unparticles to the third generation quarks on (a) pair production of same sign tops/antitops $\sigma (p\bar p\to tt+\bar t \bar t)$ at TeVatron and (b) the partial top decay width for $\Gamma_{\cal U}(t\to u\,{\cal U}^V)$. We find that a large region of parameter space is consistent with the measurements of \tt production cross-section, \afbt and spin correlation coefficient at TeVatron and observe that the top decay width measurement constrains the flavor violating coupling of vector unparticles more severely than the same sign top/antitop production at TeVatron. We also predict the best point-set in the model parameter space for specific choices of \du corresponding to $\chi^2_{\rm min}$ evaluated using the \mttb spectrum of \afbt from the data set of Run II of TeVatron at the integrated luminosity 8.7 fb$^{-1}$. Our results and analysis are consistent even with unparticle theories having broken scale invariance as long as the infrared cut-off scale is much less than the top pair production threshold.
[ { "created": "Sat, 23 Jun 2012 22:51:47 GMT", "version": "v1" }, { "created": "Mon, 9 Jul 2012 07:01:08 GMT", "version": "v2" }, { "created": "Tue, 27 Nov 2012 07:14:27 GMT", "version": "v3" } ]
2013-05-30
[ [ "Dahiya", "Mamta", "" ], [ "Dutta", "Sukanta", "" ], [ "Islam", "Rashidul", "" ] ]
We study and analyze the recent observations of the top pair production $\sigma (p\bar p\to t \bar t)$ at TeVatron through flavor conserving and flavor violating channels ${\it via}$ vector and tensor unparticles. The unparticle sector is considered with the possibility of being a color singlet or octet. The modified unparticle propagator is used to investigate the contribution of these unparticles to the observed $A_{FB}^{t\bar t}$ (forward backward asymmetry in top pair production) and the spin correlation at TeVatron. We have also studied the impact of the flavor violating couplings of unparticles to the third generation quarks on (a) pair production of same sign tops/antitops $\sigma (p\bar p\to tt+\bar t \bar t)$ at TeVatron and (b) the partial top decay width for $\Gamma_{\cal U}(t\to u\,{\cal U}^V)$. We find that a large region of parameter space is consistent with the measurements of \tt production cross-section, \afbt and spin correlation coefficient at TeVatron and observe that the top decay width measurement constrains the flavor violating coupling of vector unparticles more severely than the same sign top/antitop production at TeVatron. We also predict the best point-set in the model parameter space for specific choices of \du corresponding to $\chi^2_{\rm min}$ evaluated using the \mttb spectrum of \afbt from the data set of Run II of TeVatron at the integrated luminosity 8.7 fb$^{-1}$. Our results and analysis are consistent even with unparticle theories having broken scale invariance as long as the infrared cut-off scale is much less than the top pair production threshold.
1504.06019
Hee Sok Chung
Geoffrey T. Bodwin, Hee Sok Chung (Argonne), U-Rae Kim, Jungil Lee (Korea U.)
Fragmentation contributions to $J/\psi$ photoproduction at HERA
16 pages, 6 figures, minor revisions, version published in Phys. Rev. D
Phys. Rev. D 92, 074042 (2015)
10.1103/PhysRevD.92.074042
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute leading-power fragmentation corrections to $J/\psi$ photoproduction at DESY HERA, making use of the nonrelativistic QCD factorization approach. Our calculations include parton production cross sections through order $\alpha_s^3$, fragmentation functions though order $\alpha_s^2$, and leading logarithms of the transverse momentum divided by the charm-quark mass to all orders in $\alpha_s$. We find that the leading-power fragmentation corrections, beyond those that are included through next-to-leading order in $\alpha_s$, are small relative to the fixed-order contributions through next-to-leading order in $\alpha_s$. Consequently, an important discrepancy remains between the experimental measurements of the $J/\psi$ photoproduction cross section and predictions that make use of nonrelativistic-QCD long-distance matrix elements that are extracted from the $J/\psi$ hadroproduction cross-section and polarization data.
[ { "created": "Thu, 23 Apr 2015 01:19:21 GMT", "version": "v1" }, { "created": "Mon, 3 Aug 2015 16:11:11 GMT", "version": "v2" }, { "created": "Wed, 18 Nov 2015 16:23:44 GMT", "version": "v3" } ]
2015-11-19
[ [ "Bodwin", "Geoffrey T.", "", "Argonne" ], [ "Chung", "Hee Sok", "", "Argonne" ], [ "Kim", "U-Rae", "", "Korea U." ], [ "Lee", "Jungil", "", "Korea U." ] ]
We compute leading-power fragmentation corrections to $J/\psi$ photoproduction at DESY HERA, making use of the nonrelativistic QCD factorization approach. Our calculations include parton production cross sections through order $\alpha_s^3$, fragmentation functions though order $\alpha_s^2$, and leading logarithms of the transverse momentum divided by the charm-quark mass to all orders in $\alpha_s$. We find that the leading-power fragmentation corrections, beyond those that are included through next-to-leading order in $\alpha_s$, are small relative to the fixed-order contributions through next-to-leading order in $\alpha_s$. Consequently, an important discrepancy remains between the experimental measurements of the $J/\psi$ photoproduction cross section and predictions that make use of nonrelativistic-QCD long-distance matrix elements that are extracted from the $J/\psi$ hadroproduction cross-section and polarization data.
hep-ph/0409138
Marco Peloso
Jihn E. Kim, Hans Peter Nilles, Marco Peloso
Completing Natural Inflation
9 pages, 1 figure
JCAP 0501 (2005) 005
10.1088/1475-7516/2005/01/005
null
hep-ph astro-ph hep-th
null
If the inflaton is a pseudo-scalar axion, the axion shift symmetry can protect the flatness of its potential from too large radiative corrections. This possibility, known as natural inflation, requires an axion scale which is greater than the (reduced) Planck scale. It is unclear whether such a high value is compatible with an effective field theoretical description, and if the global axionic symmetry survives quantum gravity effects. We propose a mechanism which provides an effective large axion scale, although the original one is sub-Planckian. The mechanism is based on the presence of two axions, with a potential provided by two anomalous gauge groups. The effective large axion scale is due to an almost exact symmetry between the couplings of the axions to the anomalous groups. We also comment on a possible implementation in heterotic string theory.
[ { "created": "Sun, 12 Sep 2004 17:01:44 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kim", "Jihn E.", "" ], [ "Nilles", "Hans Peter", "" ], [ "Peloso", "Marco", "" ] ]
If the inflaton is a pseudo-scalar axion, the axion shift symmetry can protect the flatness of its potential from too large radiative corrections. This possibility, known as natural inflation, requires an axion scale which is greater than the (reduced) Planck scale. It is unclear whether such a high value is compatible with an effective field theoretical description, and if the global axionic symmetry survives quantum gravity effects. We propose a mechanism which provides an effective large axion scale, although the original one is sub-Planckian. The mechanism is based on the presence of two axions, with a potential provided by two anomalous gauge groups. The effective large axion scale is due to an almost exact symmetry between the couplings of the axions to the anomalous groups. We also comment on a possible implementation in heterotic string theory.
hep-ph/9511343
Paul Frampton
Paul H. Frampton and Otto C. W. Kong
Dicyclic Horizontal Symmetry and Supersymmetric Grand Unification
10 pages, LaTeX
Phys.Rev. D53 (1996) 2293-2295
10.1103/PhysRevD.53.R2293
IFP-715-UNC
hep-ph
null
It is shown how to use as horizontal symmetry the dicyclic group $Q_6 \subset SU(2)$ in a supersymmetric unification $SU(5)\otimes SU(5)\otimes SU(2)$ where one $SU(5)$ acts on the first and second families, in a horizontal doublet, and the other acts on the third. This can lead to acceptable quark masses and mixings, with an economic choice of matter supermultiplets, and charged lepton masses can be accommodated.
[ { "created": "Thu, 16 Nov 1995 16:04:44 GMT", "version": "v1" } ]
2009-10-28
[ [ "Frampton", "Paul H.", "" ], [ "Kong", "Otto C. W.", "" ] ]
It is shown how to use as horizontal symmetry the dicyclic group $Q_6 \subset SU(2)$ in a supersymmetric unification $SU(5)\otimes SU(5)\otimes SU(2)$ where one $SU(5)$ acts on the first and second families, in a horizontal doublet, and the other acts on the third. This can lead to acceptable quark masses and mixings, with an economic choice of matter supermultiplets, and charged lepton masses can be accommodated.
hep-ph/0007292
Bernd Andreas Kniehl
Bernd A. Kniehl, Jungil Lee (Hamburg University)
Polarized J/psi from chi_{cJ} and psi' Decays at the Tevatron
17 pages (Latex), 1 figure (Postscript)
Phys.Rev.D62:114027,2000
10.1103/PhysRevD.62.114027
DESY 00-107
hep-ph
null
We calculate the partonic cross sections for the hadroproduction of polarized chi_{cJ} mesons using the factorization formalism of nonrelativistic QCD. We also describe how the polarization is passed on to the J/psi mesons in the radiative feed-down chi_{cJ} -> J/psi + gamma and in the double-cascade decays of psi' mesons via chi_{cJ} intermediate states. These represent the missing ingredients needed to predict the polarization of prompt J/psi mesons at the Fermilab Tevatron.
[ { "created": "Wed, 26 Jul 2000 11:47:37 GMT", "version": "v1" } ]
2011-03-23
[ [ "Kniehl", "Bernd A.", "", "Hamburg University" ], [ "Lee", "Jungil", "", "Hamburg University" ] ]
We calculate the partonic cross sections for the hadroproduction of polarized chi_{cJ} mesons using the factorization formalism of nonrelativistic QCD. We also describe how the polarization is passed on to the J/psi mesons in the radiative feed-down chi_{cJ} -> J/psi + gamma and in the double-cascade decays of psi' mesons via chi_{cJ} intermediate states. These represent the missing ingredients needed to predict the polarization of prompt J/psi mesons at the Fermilab Tevatron.
1601.04472
Allen Caldwell
Allen Caldwell
The evolution of $\sigma^{\gamma P}$ with coherence length
null
null
10.1088/1367-2630/18/7/073019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Assuming the form $\sigma^{\gamma P} \propto l^{\lambda_{\rm eff}}$ at fixed $Q^2$ for the behavior of the virtual-photon proton scattering cross section, where $l$ is the coherence length of the photon fluctuations, it is seen that the extrapolated values of $\sigma^{\gamma P}$ for different $Q^2$ cross for $l\approx 10^8$~fm. It is argued that this behavior is not physical, and that the behavior of the cross sections must change before this coherence length $l$ is reached. This could set the scale for the onset of saturation of parton densities.
[ { "created": "Mon, 18 Jan 2016 11:21:33 GMT", "version": "v1" } ]
2016-08-03
[ [ "Caldwell", "Allen", "" ] ]
Assuming the form $\sigma^{\gamma P} \propto l^{\lambda_{\rm eff}}$ at fixed $Q^2$ for the behavior of the virtual-photon proton scattering cross section, where $l$ is the coherence length of the photon fluctuations, it is seen that the extrapolated values of $\sigma^{\gamma P}$ for different $Q^2$ cross for $l\approx 10^8$~fm. It is argued that this behavior is not physical, and that the behavior of the cross sections must change before this coherence length $l$ is reached. This could set the scale for the onset of saturation of parton densities.
hep-ph/0506153
Stefan W. Bosch
Stefan W. Bosch
CKM Overview and Determinations from B Decays
Contributed to XXXXth Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, March 5-12 2005
null
null
PITHA-05-08
hep-ph
null
This talk gives an introduction to the Standard Model Cabibbo-Kobayashi-Maskawa matrix and methods to extract information on the parameters of the unitarity triangle from B decays.
[ { "created": "Thu, 16 Jun 2005 10:04:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bosch", "Stefan W.", "" ] ]
This talk gives an introduction to the Standard Model Cabibbo-Kobayashi-Maskawa matrix and methods to extract information on the parameters of the unitarity triangle from B decays.
1807.02121
Gauthier Durieux
Gauthier Durieux, Mart\'in Perell\'o, Marcel Vos and Cen Zhang
Global and optimal probes for the top-quark effective field theory at future lepton colliders
6 appendices, 66 pages, 37 figures, 10 tables, codes and numerics at https://github.com/gdurieux/optimal_observables_ee2tt2bwbw
null
10.1007/JHEP10(2018)168
DESY 18-096, IFIC 18-27
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We study the sensitivity to physics beyond the standard model of precise top-quark pair production measurements at future lepton colliders. A global effective-field-theory approach is employed, including all dimension-six operators of the Warsaw basis which involve a top-quark and give rise to tree-level amplitudes that interfere with standard-model $e^+e^-\to t\,\bar t\to bW^+\bar bW^-$ ones in the limit of vanishing $b$-quark mass. Four-fermion and CP-violating contributions are taken into account. Circular-collider-, ILC- and CLIC-like benchmark run scenarios are examined. We compare the constraining power of various observables to a set of statistically optimal ones which maximally exploit the information contained in the fully differential $bW^+\bar bW^-$ distribution. The enhanced sensitivity gained on the linear contributions of dimension-six operators leads to bounds that are insensitive to quadratic ones. Even with statistically optimal observables, two centre-of-mass energies are required for constraining simultaneously two- and four-fermion operators. The impact of the centre-of-mass energy lever arm is discussed, that of beam polarization as well. A realistic estimate of the precision that can be achieved in ILC- and CLIC-like operating scenarios yields individual limits on the electroweak couplings of the top quark that are one to three orders of magnitude better than constraints set with Tevatron and LHC run I data, and three to two hundred times better than the most optimistic projections made for the high-luminosity phase of the LHC. Clean global constraints can moreover be obtained at lepton colliders, robustly covering the multidimensional effective-field-theory space with minimal model dependence.
[ { "created": "Thu, 5 Jul 2018 18:00:02 GMT", "version": "v1" } ]
2018-11-14
[ [ "Durieux", "Gauthier", "" ], [ "Perelló", "Martín", "" ], [ "Vos", "Marcel", "" ], [ "Zhang", "Cen", "" ] ]
We study the sensitivity to physics beyond the standard model of precise top-quark pair production measurements at future lepton colliders. A global effective-field-theory approach is employed, including all dimension-six operators of the Warsaw basis which involve a top-quark and give rise to tree-level amplitudes that interfere with standard-model $e^+e^-\to t\,\bar t\to bW^+\bar bW^-$ ones in the limit of vanishing $b$-quark mass. Four-fermion and CP-violating contributions are taken into account. Circular-collider-, ILC- and CLIC-like benchmark run scenarios are examined. We compare the constraining power of various observables to a set of statistically optimal ones which maximally exploit the information contained in the fully differential $bW^+\bar bW^-$ distribution. The enhanced sensitivity gained on the linear contributions of dimension-six operators leads to bounds that are insensitive to quadratic ones. Even with statistically optimal observables, two centre-of-mass energies are required for constraining simultaneously two- and four-fermion operators. The impact of the centre-of-mass energy lever arm is discussed, that of beam polarization as well. A realistic estimate of the precision that can be achieved in ILC- and CLIC-like operating scenarios yields individual limits on the electroweak couplings of the top quark that are one to three orders of magnitude better than constraints set with Tevatron and LHC run I data, and three to two hundred times better than the most optimistic projections made for the high-luminosity phase of the LHC. Clean global constraints can moreover be obtained at lepton colliders, robustly covering the multidimensional effective-field-theory space with minimal model dependence.
1809.10290
Ahmad Jafar Arifi
A. J. Arifi, H. Nagahiro, A. Hosaka
Three-Body Decay of $\Lambda_c^{*}(2595)$ and $\Lambda_c^{*}(2625)$ with the Inclusion of Direct Two-Pion Coupling
11 pages, 15 figures
Phys. Rev. D 98, 114007 (2018)
10.1103/PhysRevD.98.114007
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the three-body decays of $\Lambda_c^*(2595)$ and $\Lambda_c^*(2625)$ into $\Lambda_c \pi \pi$ by including a direct process going through the two-pion coupling of $\Lambda_c^*\Lambda_c \pi \pi$ in addition to the sequential processes going through $\Sigma_c(2455)$ and $\Sigma_c^*(2520)$. The strength of the direct coupling is related to that of the Yukawa coupling by the chiral partner structure between $\Lambda_c$'s and $\Sigma_c$'s, while the strength of the Yukawa coupling is estimated by the quark model. It is found that the direct process gives a considerable contribution especially in the decay of $\Lambda_c^*(2625)$. A clear indication of the direct process is seen in an asymmetric pattern in the angular correlation between the two pions. We discuss the usefulness of the detailed analysis of the decays for the study of the structure of $\Lambda_c^*$.
[ { "created": "Thu, 27 Sep 2018 01:04:01 GMT", "version": "v1" } ]
2018-12-19
[ [ "Arifi", "A. J.", "" ], [ "Nagahiro", "H.", "" ], [ "Hosaka", "A.", "" ] ]
We investigate the three-body decays of $\Lambda_c^*(2595)$ and $\Lambda_c^*(2625)$ into $\Lambda_c \pi \pi$ by including a direct process going through the two-pion coupling of $\Lambda_c^*\Lambda_c \pi \pi$ in addition to the sequential processes going through $\Sigma_c(2455)$ and $\Sigma_c^*(2520)$. The strength of the direct coupling is related to that of the Yukawa coupling by the chiral partner structure between $\Lambda_c$'s and $\Sigma_c$'s, while the strength of the Yukawa coupling is estimated by the quark model. It is found that the direct process gives a considerable contribution especially in the decay of $\Lambda_c^*(2625)$. A clear indication of the direct process is seen in an asymmetric pattern in the angular correlation between the two pions. We discuss the usefulness of the detailed analysis of the decays for the study of the structure of $\Lambda_c^*$.
1209.5416
Tom Steele
T.G. Steele, Zhi-Wei Wang
Is Radiative Electroweak Symmetry Breaking Consistent with a 125 GeV Higgs Mass?
5 pages, 3 eps figures included with LaTeX source. v3 contains extended analysis and discussion
Phys. Rev. Lett. 110 (2013) 151601
10.1103/PhysRevLett.110.151601
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mechanism of radiative electroweak symmetry breaking occurs through loop corrections, and unlike conventional symmetry breaking where the Higgs mass is a parameter, the radiatively-generated Higgs mass is dynamically predicted. Pade approximations and an averaging method are developed to extend the Higgs mass predictions in radiative electroweak symmetry breaking from five- to nine-loop order in the scalar sector of the Standard Model, resulting in an upper bound on the Higgs mass of 141 GeV. The mass predictions are well-described by a geometric series behaviour, converging to an asymptotic Higgs mass of 124 GeV consistent with the recent ATLAS/CMS observations. Similarly, we find that the Higgs self-coupling converges to $\lambda=0.23$, which is significantly larger than its conventional symmetry breaking counterpart for a 124 GeV Higgs mass. In addition to this significant enhancement of the Higgs self-coupling and $HH\rightarrow HH$ scattering, we find that Higgs decays to gauge bosons are unaltered and the scattering processes $W_{L}^{+}W_{L}^{+}\rightarrow HH$, $Z_{L}Z_{L}\rightarrow HH$ are also enhanced, providing signals to distinguish conventional and radiative electroweak symmetry breaking mechanisms.
[ { "created": "Mon, 24 Sep 2012 20:46:26 GMT", "version": "v1" }, { "created": "Fri, 19 Oct 2012 21:23:40 GMT", "version": "v2" }, { "created": "Fri, 5 Apr 2013 16:35:57 GMT", "version": "v3" } ]
2013-08-22
[ [ "Steele", "T. G.", "" ], [ "Wang", "Zhi-Wei", "" ] ]
The mechanism of radiative electroweak symmetry breaking occurs through loop corrections, and unlike conventional symmetry breaking where the Higgs mass is a parameter, the radiatively-generated Higgs mass is dynamically predicted. Pade approximations and an averaging method are developed to extend the Higgs mass predictions in radiative electroweak symmetry breaking from five- to nine-loop order in the scalar sector of the Standard Model, resulting in an upper bound on the Higgs mass of 141 GeV. The mass predictions are well-described by a geometric series behaviour, converging to an asymptotic Higgs mass of 124 GeV consistent with the recent ATLAS/CMS observations. Similarly, we find that the Higgs self-coupling converges to $\lambda=0.23$, which is significantly larger than its conventional symmetry breaking counterpart for a 124 GeV Higgs mass. In addition to this significant enhancement of the Higgs self-coupling and $HH\rightarrow HH$ scattering, we find that Higgs decays to gauge bosons are unaltered and the scattering processes $W_{L}^{+}W_{L}^{+}\rightarrow HH$, $Z_{L}Z_{L}\rightarrow HH$ are also enhanced, providing signals to distinguish conventional and radiative electroweak symmetry breaking mechanisms.
hep-ph/0205143
Arthur Hebecker
Arthur Hebecker, John March-Russell
The Flavour Hierarchy and See-Saw Neutrinos from Bulk Masses in 5d Orbifold GUTs
10 pages LaTeX, 1 figure. Minor comments and reference added. Version to be published in PLB
Phys.Lett. B541 (2002) 338-345
10.1016/S0370-2693(02)02244-X
CERN-TH/2002-101
hep-ph
null
In supersymmetric grand unified theories (GUTs) based on S^1/(Z_2 x Z'_2) orbifold constructions in 5 dimensions, Standard Model (SM) matter and Higgs fields can be realized in terms of 5d hypermultiplets. These hypermultiplets can naturally have large bulk masses, leading to a localization of the zero modes at one of the two branes or to an exponential suppression of the mass of the lowest-lying non-zero mode. We demonstrate that these dynamical features allow for the construction of an elegant 3-generation SU(5) model in 5 dimensions that explains all the hierarchies between fermion masses and CKM matrix elements in geometrical terms. Moreover, if U(1)_\chi (where SU(5) x U(1)_\chi \subset SO(10)) is gauged in the bulk, but broken by the orbifold action at the SM brane, the right-handed neutrino mass scale is naturally suppressed relative to M_GUT. Together with our construction in the charged fermion sector this leads, via the usual see-saw mechanism, to a realistic light neutrino mass scale and large neutrino mixing angles.
[ { "created": "Tue, 14 May 2002 16:27:03 GMT", "version": "v1" }, { "created": "Fri, 5 Jul 2002 12:45:32 GMT", "version": "v2" } ]
2009-11-07
[ [ "Hebecker", "Arthur", "" ], [ "March-Russell", "John", "" ] ]
In supersymmetric grand unified theories (GUTs) based on S^1/(Z_2 x Z'_2) orbifold constructions in 5 dimensions, Standard Model (SM) matter and Higgs fields can be realized in terms of 5d hypermultiplets. These hypermultiplets can naturally have large bulk masses, leading to a localization of the zero modes at one of the two branes or to an exponential suppression of the mass of the lowest-lying non-zero mode. We demonstrate that these dynamical features allow for the construction of an elegant 3-generation SU(5) model in 5 dimensions that explains all the hierarchies between fermion masses and CKM matrix elements in geometrical terms. Moreover, if U(1)_\chi (where SU(5) x U(1)_\chi \subset SO(10)) is gauged in the bulk, but broken by the orbifold action at the SM brane, the right-handed neutrino mass scale is naturally suppressed relative to M_GUT. Together with our construction in the charged fermion sector this leads, via the usual see-saw mechanism, to a realistic light neutrino mass scale and large neutrino mixing angles.
hep-ph/0411371
Jean-Rene Cudell
O.V. Selyugin, J.R. Cudell and E. Predazzi
Large-distance effects on spin observables at RHIC
LaTeX, 5 pages, 3 figures, presented by O.V.S. at the 16th International Spin Physics Symposium, spin2004, October 10-16 2004, Trieste, Italy. Fig. 3 corrected in version 2
null
10.1142/9789812701909_0105
null
hep-ph
null
The impact of large-distance contributions on the behaviour of the slopes of the spin-non-flip and of the spin-flip amplitudes is analysed. It is shown that the long tail of the hadron potential in impact parameter space leads to a larger value of the slope for the spin-flip amplitude (without the kinematic factor sqrt(|t|)) than for the spin-non-flip amplitude. This effect is taken into account in the calculation of the analysing power in proton-nucleus reactions at high energies.
[ { "created": "Mon, 29 Nov 2004 14:04:58 GMT", "version": "v1" }, { "created": "Wed, 22 Dec 2004 13:48:07 GMT", "version": "v2" } ]
2017-08-23
[ [ "Selyugin", "O. V.", "" ], [ "Cudell", "J. R.", "" ], [ "Predazzi", "E.", "" ] ]
The impact of large-distance contributions on the behaviour of the slopes of the spin-non-flip and of the spin-flip amplitudes is analysed. It is shown that the long tail of the hadron potential in impact parameter space leads to a larger value of the slope for the spin-flip amplitude (without the kinematic factor sqrt(|t|)) than for the spin-non-flip amplitude. This effect is taken into account in the calculation of the analysing power in proton-nucleus reactions at high energies.
1312.0874
Bennie F. L. Ward
B.F.L. Ward (1), S.K. Majhi (2), A. Mukhopadhyay (1), S.A. Yost (3) ((1) Baylor Univesity, Waco, TX, USA, (2) Indian Association for the Cultivation of Science, Kolkata, IN, (3) The Citadel, Charleston, SC, USA)
Comparisons of Predictions from Exact Amplitude-Based Resummation Methods with LHC and Cosmological Data
9 pages, 2 figures; presented by B.F.L. Ward at RADCOR 2013, Durham, UK
null
null
BU-HEPP-13-04
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the current status of the comparisons with the respective data of the predictions of our approach of exact amplitude-based resummation in quantum field theory in two areas of investigation: precision QCD calculations of all four of us as needed for LHC physics and the resummed quantum gravity realization by one of us (B.F.L.W.) of Einstein's theory of general relativity as formulated by Feynman. The agreement between the theoretical predictions and the data exhibited continues to be encouraging.
[ { "created": "Tue, 3 Dec 2013 16:18:02 GMT", "version": "v1" } ]
2013-12-04
[ [ "Ward", "B. F. L.", "" ], [ "Majhi", "S. K.", "" ], [ "Mukhopadhyay", "A.", "" ], [ "Yost", "S. A.", "" ] ]
We present the current status of the comparisons with the respective data of the predictions of our approach of exact amplitude-based resummation in quantum field theory in two areas of investigation: precision QCD calculations of all four of us as needed for LHC physics and the resummed quantum gravity realization by one of us (B.F.L.W.) of Einstein's theory of general relativity as formulated by Feynman. The agreement between the theoretical predictions and the data exhibited continues to be encouraging.
1411.7686
Pratishruti Saha
Pratishruti Saha
Search for New Physics in Rare Top Decays
Contribution to TOP 2014 - the 7th International Workshop on Top Quark Physics
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Top physics provides a fertile ground for new-physics searches. At present, most top observables appear to be in good agreement with the respective Standard Model predictions. However, in the case of decay modes that are suppressed in the Standard Model, new-physics contributions of comparable magnitude may exist and yet go unnoticed because their impact on the total decay width is small. Hence it is interesting to probe rare top decays. This analysis focuses on the decay $t \to b \bar b c$. Useful observables are identified and prospects for measuring new-physics parameters are examined.
[ { "created": "Thu, 27 Nov 2014 19:30:14 GMT", "version": "v1" } ]
2014-12-01
[ [ "Saha", "Pratishruti", "" ] ]
Top physics provides a fertile ground for new-physics searches. At present, most top observables appear to be in good agreement with the respective Standard Model predictions. However, in the case of decay modes that are suppressed in the Standard Model, new-physics contributions of comparable magnitude may exist and yet go unnoticed because their impact on the total decay width is small. Hence it is interesting to probe rare top decays. This analysis focuses on the decay $t \to b \bar b c$. Useful observables are identified and prospects for measuring new-physics parameters are examined.
hep-ph/9402210
Chris Quigg
Estia J. Eichten and Chris Quigg
Mesons with Beauty and Charm: Spectroscopy
32 pages + 2 uuencoded PostScript figures Fermilab-Pub-94/032-T
Phys.Rev.D49:5845-5856,1994
10.1103/PhysRevD.49.5845
null
hep-ph
null
Applying knowledge of the interaction between heavy quarks derived from the study of $c\overline{c}$ and $b\overline{b}$ bound states, we calculate the spectrum of $c\overline{b}$ mesons. We compute transition rates for the electromagnetic and hadronic cascades that lead from excited states to the $^1\text{S}_0$ ground state, and briefly consider the prospects for experimental observation of the spectrum.
[ { "created": "Wed, 2 Feb 1994 21:08:39 GMT", "version": "v1" } ]
2009-09-25
[ [ "Eichten", "Estia J.", "" ], [ "Quigg", "Chris", "" ] ]
Applying knowledge of the interaction between heavy quarks derived from the study of $c\overline{c}$ and $b\overline{b}$ bound states, we calculate the spectrum of $c\overline{b}$ mesons. We compute transition rates for the electromagnetic and hadronic cascades that lead from excited states to the $^1\text{S}_0$ ground state, and briefly consider the prospects for experimental observation of the spectrum.
1409.6347
Sener Ozonder
Sener Ozonder
Triple- and Quadruple-Gluon Azimuthal Correlations from Glasma and Higher-Dimensional Ridges
Only the published version includes the latest changes (more explanations and references)
Phys. Rev. D 91, 034005 (2015)
10.1103/PhysRevD.91.034005
INT-PUB-14-022
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the triple- and quadruple-gluon inclusive distributions with arbitrary rapidity and azimuthal angle dependences in the gluon saturation regime by using glasma diagrams. Also, we predict higher-dimensional ridges in triple- and quadruple-hadron correlations for p-p and p-Pb collisions at LHC, which have yet to be measured. In p-p and p-Pb collisions at the top LHC energies, gluon saturation is expected to occur since smaller Bjorken-$x$ values are being probed. Glasma diagrams, which are enhanced at small-$x$, include the gluon saturation effects, and they are used for calculating the long-range rapidity correlations ("ridges") and $v_n$ moments of the azimuthal distribution of detected hadrons. The glasma description reproduces the systematics of the data on both p-p and p-Pb ridges. As an alternative, relativistic hydrodynamics has also been applied to these small systems quite successfully. With the triple- and quadruple-gluon azimuthal correlations, this work aims to set the stage by going beyond the double-gluon azimuthal correlations in order to settle unambiguously the origin of "collectivity" in p-p and p-Pb collisions. We derive the triple- and quadruple-gluon azimuthal correlation functions in terms of unintegrated gluon distributions at arbitrary rapidities and azimuthal angles of the produced gluons. Then, unintegrated gluon distributions from the running coupling Balitsky-Kovchegov evolution equation are used to calculate the triple- and quadruple-gluon correlations for various parameters of gluon momenta, initial scale for small-$x$ evolution and beam energy.
[ { "created": "Mon, 22 Sep 2014 21:34:17 GMT", "version": "v1" }, { "created": "Wed, 11 Feb 2015 02:24:24 GMT", "version": "v2" } ]
2015-02-12
[ [ "Ozonder", "Sener", "" ] ]
We calculate the triple- and quadruple-gluon inclusive distributions with arbitrary rapidity and azimuthal angle dependences in the gluon saturation regime by using glasma diagrams. Also, we predict higher-dimensional ridges in triple- and quadruple-hadron correlations for p-p and p-Pb collisions at LHC, which have yet to be measured. In p-p and p-Pb collisions at the top LHC energies, gluon saturation is expected to occur since smaller Bjorken-$x$ values are being probed. Glasma diagrams, which are enhanced at small-$x$, include the gluon saturation effects, and they are used for calculating the long-range rapidity correlations ("ridges") and $v_n$ moments of the azimuthal distribution of detected hadrons. The glasma description reproduces the systematics of the data on both p-p and p-Pb ridges. As an alternative, relativistic hydrodynamics has also been applied to these small systems quite successfully. With the triple- and quadruple-gluon azimuthal correlations, this work aims to set the stage by going beyond the double-gluon azimuthal correlations in order to settle unambiguously the origin of "collectivity" in p-p and p-Pb collisions. We derive the triple- and quadruple-gluon azimuthal correlation functions in terms of unintegrated gluon distributions at arbitrary rapidities and azimuthal angles of the produced gluons. Then, unintegrated gluon distributions from the running coupling Balitsky-Kovchegov evolution equation are used to calculate the triple- and quadruple-gluon correlations for various parameters of gluon momenta, initial scale for small-$x$ evolution and beam energy.
hep-ph/0209207
Martti Raidal
A. Dedes, J. Ellis and M. Raidal
Higgs-Mediated $B_{s,d}^0\to\mu\tau, e\tau$ and $\tau\to3\mu, e\mu\mu$ Decays in Supersymmetric Seesaw Models
13 pages, 8 postscript figures
Phys.Lett.B549:159-169,2002
10.1016/S0370-2693(02)02900-3
CERN-TH/2002-239
hep-ph
null
We study the rates allowed for the Higgs-mediated decays $B_{s,d}^0\to\mu\tau, e\tau$ and $\tau\to \mu\mu\mu, e\mu\mu$ in supersymmetric seesaw models, assuming that the only source of lepton flavour violation (LFV) is the renormalization of soft supersymmetry-breaking terms due to off-diagonal singlet-neutrino Yukawa interactions. These decays are strongly correlated with, and constrained by, the branching ratios for $B_{s,d}^0\to\mu\mu$ and $\tau\to \mu(e)\gamma.$ Parametrizing the singlet-neutrino Yukawa couplings $Y_\nu$ and masses $M_{N_i}$ in terms of low-energy neutrino data, and allowing the flavour-universal soft masses for sleptons and for squarks, as well as those for the two Higgs doublets, to be different at the unification scale, we scan systematically over the model parameter space. Neutrino data and the present experimental constraints set upper limits on the Higgs-mediated LFV decay rates $Br(B_{s}^0\to\mu\tau, e\tau)\lsim 4\times 10^{-9}$ and $Br(\tau\to\mu\mu\mu, e\mu\mu)\lsim 4\times 10^{-10}$.
[ { "created": "Wed, 18 Sep 2002 16:31:20 GMT", "version": "v1" } ]
2009-09-11
[ [ "Dedes", "A.", "" ], [ "Ellis", "J.", "" ], [ "Raidal", "M.", "" ] ]
We study the rates allowed for the Higgs-mediated decays $B_{s,d}^0\to\mu\tau, e\tau$ and $\tau\to \mu\mu\mu, e\mu\mu$ in supersymmetric seesaw models, assuming that the only source of lepton flavour violation (LFV) is the renormalization of soft supersymmetry-breaking terms due to off-diagonal singlet-neutrino Yukawa interactions. These decays are strongly correlated with, and constrained by, the branching ratios for $B_{s,d}^0\to\mu\mu$ and $\tau\to \mu(e)\gamma.$ Parametrizing the singlet-neutrino Yukawa couplings $Y_\nu$ and masses $M_{N_i}$ in terms of low-energy neutrino data, and allowing the flavour-universal soft masses for sleptons and for squarks, as well as those for the two Higgs doublets, to be different at the unification scale, we scan systematically over the model parameter space. Neutrino data and the present experimental constraints set upper limits on the Higgs-mediated LFV decay rates $Br(B_{s}^0\to\mu\tau, e\tau)\lsim 4\times 10^{-9}$ and $Br(\tau\to\mu\mu\mu, e\mu\mu)\lsim 4\times 10^{-10}$.
1001.5456
Roberto Barcelo
Roberto Barcelo, Manuel Masip
Extra Higgs bosons in ttbar production at the LHC
18 pages, version to appear in PRD
Phys.Rev.D81:075019,2010
10.1103/PhysRevD.81.075019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The top quark has a large Yukawa coupling with the Higgs boson. In the usual extensions of the standard model the Higgs sector includes extra scalars, which also tend to couple strongly with the top quark. Unlike the Higgs, these fields have a natural mass above 2m_t, so they could introduce anomalies in ttbar production at the LHC. We study their effect on the ttbar invariant mass distribution at sqrt{s}=7 TeV. We focus on the bosons (H,A) of the minimal SUSY model and on the scalar field (r) associated to the new scale f in Little Higgs (LH) models. We show that in all cases the interference with the standard amplitude dominates over the narrow-width contribution. As a consequence, the mass difference between H and A or the contribution of an extra T-quark loop in LH models become important effects in order to determine if these fields are observable there. We find that a 1 fb^{-1} luminosity could probe the region tan beta \le 3 of SUSY and v/(sqrt{2}f) \ge 0.3 in LH models.
[ { "created": "Fri, 29 Jan 2010 19:19:39 GMT", "version": "v1" }, { "created": "Tue, 2 Feb 2010 16:30:27 GMT", "version": "v2" }, { "created": "Mon, 15 Feb 2010 14:31:21 GMT", "version": "v3" }, { "created": "Tue, 6 Apr 2010 10:39:14 GMT", "version": "v4" } ]
2015-03-13
[ [ "Barcelo", "Roberto", "" ], [ "Masip", "Manuel", "" ] ]
The top quark has a large Yukawa coupling with the Higgs boson. In the usual extensions of the standard model the Higgs sector includes extra scalars, which also tend to couple strongly with the top quark. Unlike the Higgs, these fields have a natural mass above 2m_t, so they could introduce anomalies in ttbar production at the LHC. We study their effect on the ttbar invariant mass distribution at sqrt{s}=7 TeV. We focus on the bosons (H,A) of the minimal SUSY model and on the scalar field (r) associated to the new scale f in Little Higgs (LH) models. We show that in all cases the interference with the standard amplitude dominates over the narrow-width contribution. As a consequence, the mass difference between H and A or the contribution of an extra T-quark loop in LH models become important effects in order to determine if these fields are observable there. We find that a 1 fb^{-1} luminosity could probe the region tan beta \le 3 of SUSY and v/(sqrt{2}f) \ge 0.3 in LH models.
1811.12394
Nikolay Volchanskiy
N. Volchanskiy, V. Beylin, V. Kuksa
Models of hypercolor based on symplectic gauge group with three heavy vectorlike hyperquarks
15 pages
Int. J. Mod. Phys. D, ID 1941002 (2019)
10.1142/S0218271819410025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study possibilities to extend the Standard Model (SM) by three flavors of vectorlike heavy quarks in pseudoreal representation of symplectic hypercolor gauge group. This extension of SM predicts a rich spectra of heavy composite hypermesons and hyperbaryons (all of them carry integer spins) including fourteen pseudo-Nambu--Goldstone states emerging in dynamical breaking of the global symmetry group of the H-quarks, SU(6), to its Sp(6) subgroup. The properties of the lightest states depend strongly on the choice of heavy-quark hypercharges. Our focus is placed on the variants of the model with partially composite Higgs boson, i.e. the experimentally observed boson is comprised of the elementary SM Higgs and a mixture of H-hadrons.
[ { "created": "Thu, 29 Nov 2018 18:57:36 GMT", "version": "v1" } ]
2019-02-01
[ [ "Volchanskiy", "N.", "" ], [ "Beylin", "V.", "" ], [ "Kuksa", "V.", "" ] ]
We study possibilities to extend the Standard Model (SM) by three flavors of vectorlike heavy quarks in pseudoreal representation of symplectic hypercolor gauge group. This extension of SM predicts a rich spectra of heavy composite hypermesons and hyperbaryons (all of them carry integer spins) including fourteen pseudo-Nambu--Goldstone states emerging in dynamical breaking of the global symmetry group of the H-quarks, SU(6), to its Sp(6) subgroup. The properties of the lightest states depend strongly on the choice of heavy-quark hypercharges. Our focus is placed on the variants of the model with partially composite Higgs boson, i.e. the experimentally observed boson is comprised of the elementary SM Higgs and a mixture of H-hadrons.
hep-ph/9609346
D. Delepine
D. Delepine
Electroweak baryogenesis and the Minimal Supersymmetric Standard Model
8 pages with 1 figure(eps)
NATO Adv.Study Inst.Ser.B Phys.363:293-299,1997
null
UCL-IPT-96-12
hep-ph
null
In principle, the baryon asymmetry of the Universe can be generated at the electroweak phase transition but the experimental lower limit on the Higgs mass seems to rule out a Standard Model scenario. However, it has been shown recently that in the Minimal Supersymmetric Standard Model, the electroweak phase transition can be a strong enough first order one for baryogenesis if the mass of one top squark is close to or smaller than the top mass.
[ { "created": "Fri, 13 Sep 1996 11:13:39 GMT", "version": "v1" } ]
2009-02-16
[ [ "Delepine", "D.", "" ] ]
In principle, the baryon asymmetry of the Universe can be generated at the electroweak phase transition but the experimental lower limit on the Higgs mass seems to rule out a Standard Model scenario. However, it has been shown recently that in the Minimal Supersymmetric Standard Model, the electroweak phase transition can be a strong enough first order one for baryogenesis if the mass of one top squark is close to or smaller than the top mass.