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1003.2853
Kazunari Yamamoto
K. Yamamoto
On the Independent Crossing Approximation in Three Flavor Neutrino Oscillations
19 pages, 8 figures.
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In dense matter like the Supernovae and at high energy, neutrinos have two points where the nonadiabatic transitions could occur. With the present values of the oscillation parameters in the standard three flavor scenario, two nonadiabatic transitions can be regarded as independent, i.e., two can be treated by the two flavor formalism separately. However, in the presence of new physics, it is not clear in general whether such independence holds. We examine this question by assuming hypothetical range of the neutrino energy and by varying the mixing angles and the mass squared differences in the standard case. We found the cases where Independent Crossing Approximation breaks down for some unrealistic range of the mass squared difference and the mixing angle. We also discuss the criterion which gives such independence.
[ { "created": "Mon, 15 Mar 2010 06:55:57 GMT", "version": "v1" } ]
2010-03-16
[ [ "Yamamoto", "K.", "" ] ]
In dense matter like the Supernovae and at high energy, neutrinos have two points where the nonadiabatic transitions could occur. With the present values of the oscillation parameters in the standard three flavor scenario, two nonadiabatic transitions can be regarded as independent, i.e., two can be treated by the two flavor formalism separately. However, in the presence of new physics, it is not clear in general whether such independence holds. We examine this question by assuming hypothetical range of the neutrino energy and by varying the mixing angles and the mass squared differences in the standard case. We found the cases where Independent Crossing Approximation breaks down for some unrealistic range of the mass squared difference and the mixing angle. We also discuss the criterion which gives such independence.
0706.1934
J\"org Ruppert
Jorg Ruppert, Charles Gale, Thorsten Renk, Peter Lichard, Joseph I. Kapusta
Low Mass Dimuons Produced in Relativistic Nuclear Collisions
4 pages, 3 figures, updated hadronic analysis
Phys.Rev.Lett.100:162301,2008
10.1103/PhysRevLett.100.162301
null
hep-ph
null
The NA60 experiment has measured low-mass muon pair production in In-In collisions at 158 A GeV with unprecedented precision. We show that this data is reproduced very well by a dynamical model with parameters scaled from fits to measurements of hadronic transverse mass spectra and Hanbury-Brown and Twiss correlations in Pb-Pb and Pb-Au collisions at the same energy. The data is consistent with in-medium properties of $\rho$ and $\omega$-mesons at finite temperature and density as deduced from empirical forward-scattering amplitudes. Inclusion of the vacuum decay of the $\rho$-meson after freeze-out is necessary for an understanding of the mass and transverse momentum spectrum of dimuons with $M \apprle 0.9 {\rm GeV}/c^2$.
[ { "created": "Wed, 13 Jun 2007 15:40:26 GMT", "version": "v1" }, { "created": "Fri, 15 Jun 2007 13:29:12 GMT", "version": "v2" }, { "created": "Wed, 10 Oct 2007 18:07:54 GMT", "version": "v3" } ]
2008-11-26
[ [ "Ruppert", "Jorg", "" ], [ "Gale", "Charles", "" ], [ "Renk", "Thorsten", "" ], [ "Lichard", "Peter", "" ], [ "Kapusta", "Joseph I.", "" ] ]
The NA60 experiment has measured low-mass muon pair production in In-In collisions at 158 A GeV with unprecedented precision. We show that this data is reproduced very well by a dynamical model with parameters scaled from fits to measurements of hadronic transverse mass spectra and Hanbury-Brown and Twiss correlations in Pb-Pb and Pb-Au collisions at the same energy. The data is consistent with in-medium properties of $\rho$ and $\omega$-mesons at finite temperature and density as deduced from empirical forward-scattering amplitudes. Inclusion of the vacuum decay of the $\rho$-meson after freeze-out is necessary for an understanding of the mass and transverse momentum spectrum of dimuons with $M \apprle 0.9 {\rm GeV}/c^2$.
2103.07260
Li-Sheng Geng
Rui-Xiang Shi and Li-Sheng Geng
Magnetic moments of the spin-$\frac{3}{2}$ doubly charmed baryons in covariant baryon chiral perturbation theory
a sign problem corrected, and comparion with the lattice QCD data added
Phys. Rev. D 103, 114004 (2021)
10.1103/PhysRevD.103.114004
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the discovery of the spin-$\frac{1}{2}$ doubly charmed baryon $\Xi_{cc}^{++}$ and the subsequent theoretical studies of its magnetic moments, we study the magnetic moments of its spin-$\frac{3}{2}$ heavy quark spin symmetry counterparts, up to the next-to-leading order in covariant baryon chiral perturbation theory (BChPT) with the extended-on-mass-shell renormalization (EOMS) scheme. With the tree-level contributions fixed by the quark model while the two low energy constants (LECs) $C$ and $H$ controlling the loop contributions determined in two ways: the quark model (case 1) and lattice QCD simulations together with the quark model (case 2), we study the quark mass dependence of the magnetic moments and compare them with the predictions of the heavy baryon chiral perturbation theory (HB ChPT). It is shown that the difference is sizable in case 1, but not in case 2 due to the smaller LECs $C$ and $H$, similar to the case of spin-$\frac{1}{2}$ doubly charmed baryons. Second, we predict the magnetic moments of the spin-$\frac{3}{2}$ doubly charmed baryons and compare them with those of other approaches. The predicted magnetic moments in case 2 for the spin-$\frac{3}{2}$ doubly charmed baryons are closer to those of other approaches. In addition, the large differences in case 1 and case 2 for the predicted magnetic moments may indicate the inconsistency between the quark model and the lattice QCD simulations, which should be checked by future experimental or more lattice QCD data.
[ { "created": "Fri, 12 Mar 2021 13:29:56 GMT", "version": "v1" }, { "created": "Thu, 18 Mar 2021 14:37:22 GMT", "version": "v2" } ]
2021-06-09
[ [ "Shi", "Rui-Xiang", "" ], [ "Geng", "Li-Sheng", "" ] ]
Inspired by the discovery of the spin-$\frac{1}{2}$ doubly charmed baryon $\Xi_{cc}^{++}$ and the subsequent theoretical studies of its magnetic moments, we study the magnetic moments of its spin-$\frac{3}{2}$ heavy quark spin symmetry counterparts, up to the next-to-leading order in covariant baryon chiral perturbation theory (BChPT) with the extended-on-mass-shell renormalization (EOMS) scheme. With the tree-level contributions fixed by the quark model while the two low energy constants (LECs) $C$ and $H$ controlling the loop contributions determined in two ways: the quark model (case 1) and lattice QCD simulations together with the quark model (case 2), we study the quark mass dependence of the magnetic moments and compare them with the predictions of the heavy baryon chiral perturbation theory (HB ChPT). It is shown that the difference is sizable in case 1, but not in case 2 due to the smaller LECs $C$ and $H$, similar to the case of spin-$\frac{1}{2}$ doubly charmed baryons. Second, we predict the magnetic moments of the spin-$\frac{3}{2}$ doubly charmed baryons and compare them with those of other approaches. The predicted magnetic moments in case 2 for the spin-$\frac{3}{2}$ doubly charmed baryons are closer to those of other approaches. In addition, the large differences in case 1 and case 2 for the predicted magnetic moments may indicate the inconsistency between the quark model and the lattice QCD simulations, which should be checked by future experimental or more lattice QCD data.
1611.09855
Duccio Pappadopulo
Marco Farina, Duccio Pappadopulo, Fabrizio Rompineve, Andrea Tesi
The photo-philic QCD axion
22 pages, 5 figures. Experimental signature from CASPEr-wind added
JHEP 1701 (2017) 095
10.1007/JHEP01(2017)095
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a framework in which the QCD axion has an exponentially large coupling to photons, relying on the "clockwork" mechanism. We discuss the impact of present and future axion experiments on the parameter space of the model. In addition to the axion, the model predicts a large number of pseudo-scalars which can be light and observable at the LHC. In the most favorable scenario, axion Dark Matter will give a signal in multiple axion detection experiments and the pseudo-scalars will be discovered at the LHC, allowing to determine most of the parameters of the model.
[ { "created": "Tue, 29 Nov 2016 21:00:00 GMT", "version": "v1" }, { "created": "Mon, 30 Jan 2017 18:10:56 GMT", "version": "v2" } ]
2017-01-31
[ [ "Farina", "Marco", "" ], [ "Pappadopulo", "Duccio", "" ], [ "Rompineve", "Fabrizio", "" ], [ "Tesi", "Andrea", "" ] ]
We propose a framework in which the QCD axion has an exponentially large coupling to photons, relying on the "clockwork" mechanism. We discuss the impact of present and future axion experiments on the parameter space of the model. In addition to the axion, the model predicts a large number of pseudo-scalars which can be light and observable at the LHC. In the most favorable scenario, axion Dark Matter will give a signal in multiple axion detection experiments and the pseudo-scalars will be discovered at the LHC, allowing to determine most of the parameters of the model.
hep-ph/0111176
Domenico Falcone
D. Falcone
Baryon asymmetry and mass matrices
11 pages, RevTex. Comment added
Phys.Rev. D65 (2002) 077301
10.1103/PhysRevD.65.077301
DSF-35/2001
hep-ph
null
In the framework of the baryogenesis via leptogenesis mechanism we study the link between the amount of baryon asymmetry and neutrino mass matrices. In particular, neglecting phases, we find that if the Dirac neutrino mass matrix is related to the up quark mass matrix, the baryon asymmetry is about three orders smaller than the required value. If the Dirac neutrino mass matrix is related to the down quark or the charged lepton mass matrix, the baryon asymmetry is about two orders smaller than the required value. In order to get a sufficient amount of baryon asymmetry we need a more moderate hierarchy in the Dirac neutrino mass matrix.
[ { "created": "Wed, 14 Nov 2001 13:02:52 GMT", "version": "v1" }, { "created": "Fri, 23 Nov 2001 09:21:59 GMT", "version": "v2" } ]
2009-11-07
[ [ "Falcone", "D.", "" ] ]
In the framework of the baryogenesis via leptogenesis mechanism we study the link between the amount of baryon asymmetry and neutrino mass matrices. In particular, neglecting phases, we find that if the Dirac neutrino mass matrix is related to the up quark mass matrix, the baryon asymmetry is about three orders smaller than the required value. If the Dirac neutrino mass matrix is related to the down quark or the charged lepton mass matrix, the baryon asymmetry is about two orders smaller than the required value. In order to get a sufficient amount of baryon asymmetry we need a more moderate hierarchy in the Dirac neutrino mass matrix.
1210.8038
Diogo Boito
Martin Beneke, Diogo Boito, and Matthias Jamin
Perturbative expansion of tau hadronic spectral function moments and alpha_s extractions
35 pages, 7 figures
null
10.1007/JHEP01(2013)125
UAB-FT-723, TUM-HEP-863/12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Various moments of the hadronic spectral functions have been employed in the determination of the strong coupling alpha_s from tau decays. In this work we study the behaviour of their perturbative series under different assumptions for the large-order behaviour of the Adler function, extending previous work on the tau hadronic width. We find that the moments can be divided into a small number of classes, whose characteristics depend only on generic features of the moment weight function and Adler function series. Some moments that are commonly employed in alpha_s analyses from tau decays should be avoided because of their perturbative instability. This conclusion is corroborated by a simplified alpha_s extraction from individual moments. Furthermore, under reasonable assumptions for the higher-order behaviour of the perturbative series, fixed-order perturbation theory (FOPT) provides the preferred framework for the renormalization group improvement of all moments that show good perturbative behaviour. Finally, we provide further evidence for the plausibility of the description of the Adler function in terms of a small number of leading renormalon singularities.
[ { "created": "Tue, 30 Oct 2012 15:00:22 GMT", "version": "v1" } ]
2015-06-11
[ [ "Beneke", "Martin", "" ], [ "Boito", "Diogo", "" ], [ "Jamin", "Matthias", "" ] ]
Various moments of the hadronic spectral functions have been employed in the determination of the strong coupling alpha_s from tau decays. In this work we study the behaviour of their perturbative series under different assumptions for the large-order behaviour of the Adler function, extending previous work on the tau hadronic width. We find that the moments can be divided into a small number of classes, whose characteristics depend only on generic features of the moment weight function and Adler function series. Some moments that are commonly employed in alpha_s analyses from tau decays should be avoided because of their perturbative instability. This conclusion is corroborated by a simplified alpha_s extraction from individual moments. Furthermore, under reasonable assumptions for the higher-order behaviour of the perturbative series, fixed-order perturbation theory (FOPT) provides the preferred framework for the renormalization group improvement of all moments that show good perturbative behaviour. Finally, we provide further evidence for the plausibility of the description of the Adler function in terms of a small number of leading renormalon singularities.
2405.15309
Ying Li
Qin Chang, Lei Yang, Zhi-Tian Zou, Ying Li
Study of the $B^{+}\to\pi^{+}\left(\pi^{+}\pi^{-}\right)$ decay in PQCD Approach
17 pages, 5 figure
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Based on the fitting results of the LHCb collaboration on the contributions of various intermediate resonances to the $B^{+}\to\pi^{+}\pi^{+}\pi^{-}$ decay, we make systematically calculate the branching fractions and localized $CP$ asymmetries of the quasi-two-body $B^{+}\to \pi^{+} \left( \rho(770), \omega(782), \rho(1450), f_{2}\left(1270\right)\to\right)\pi^{+}\pi^{-}$ decays within the perturbative QCD (PQCD) approach. Our theoretical predictions for the branching fractions agree well with the data within the errors. In order to further test the framework of the three-body $B$ decays in PQCD and the wave functions of $\pi\pi$ pair, we also calculate the branching fractions of the corresponding two-body $B^{+}\to\pi^{+}\rho(770)$, $B^{+}\to\pi^{+}\omega(782)$ and $B^{+}\to\pi^{+}f_{2}\left(1270\right)$ decays under the narrow-width-approximation, which are in consistence with the experimental data. The direct $CP$ asymmetries of $B^{+}\to\pi^{+}(\rho(770/1450)\to) \pi^{+}\pi^{-}$ decays are found to be very small because these decay modes are tree-dominated. However, due to the large penguin contributions from the chiral enhanced annihilation diagrams, $B^{+}\to\pi^{+} (f_{2}\left(1270\right)\to )\pi^{+}\pi^{-}$ decay has a large direct $CP$ asymmetry, which is also discovered by LHCb collaboration. A relatively large $CP$ asymmetry is also expected in the $B^+\to\pi^+ (\omega\to)\pi^+\pi^-$ decay occurring via $\rho-\omega$ mixing, which would be measured LHCb and Belle-II experiments in future.
[ { "created": "Fri, 24 May 2024 07:52:09 GMT", "version": "v1" } ]
2024-05-27
[ [ "Chang", "Qin", "" ], [ "Yang", "Lei", "" ], [ "Zou", "Zhi-Tian", "" ], [ "Li", "Ying", "" ] ]
Based on the fitting results of the LHCb collaboration on the contributions of various intermediate resonances to the $B^{+}\to\pi^{+}\pi^{+}\pi^{-}$ decay, we make systematically calculate the branching fractions and localized $CP$ asymmetries of the quasi-two-body $B^{+}\to \pi^{+} \left( \rho(770), \omega(782), \rho(1450), f_{2}\left(1270\right)\to\right)\pi^{+}\pi^{-}$ decays within the perturbative QCD (PQCD) approach. Our theoretical predictions for the branching fractions agree well with the data within the errors. In order to further test the framework of the three-body $B$ decays in PQCD and the wave functions of $\pi\pi$ pair, we also calculate the branching fractions of the corresponding two-body $B^{+}\to\pi^{+}\rho(770)$, $B^{+}\to\pi^{+}\omega(782)$ and $B^{+}\to\pi^{+}f_{2}\left(1270\right)$ decays under the narrow-width-approximation, which are in consistence with the experimental data. The direct $CP$ asymmetries of $B^{+}\to\pi^{+}(\rho(770/1450)\to) \pi^{+}\pi^{-}$ decays are found to be very small because these decay modes are tree-dominated. However, due to the large penguin contributions from the chiral enhanced annihilation diagrams, $B^{+}\to\pi^{+} (f_{2}\left(1270\right)\to )\pi^{+}\pi^{-}$ decay has a large direct $CP$ asymmetry, which is also discovered by LHCb collaboration. A relatively large $CP$ asymmetry is also expected in the $B^+\to\pi^+ (\omega\to)\pi^+\pi^-$ decay occurring via $\rho-\omega$ mixing, which would be measured LHCb and Belle-II experiments in future.
1808.04154
Joe Davighi
Joe Davighi, Ben Gripaios
Topological terms in Composite Higgs Models
26 pages. Version accepted for publication in JHEP
null
10.1007/JHEP11(2018)169
DAMTP-2018-08-14
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply a recent classification of topological action terms to Composite Higgs models based on a variety of coset spaces $G/H$ and discuss their phenomenology. The topological terms, which can all be obtained by integrating (possibly only locally-defined) differential forms, come in one of two types, with substantially differing consequences for phenomenology. The first type of term (which appears in the minimal model based on $SO(5)/SO(4)$) is a field theory generalization of the Aharonov-Bohm phase in quantum mechanics. The phenomenological effects of such a term arise only at the non-perturbative level, and lead to $P$ and $CP$ violation in the Higgs sector. The second type of term (which appears in the model based on $SO(6)/SO(5)$) is a field theory generalization of the Dirac monopole in quantum mechanics and has physical effects even at the classical level. Perhaps most importantly, measuring the coefficient of such a term can allow one to probe the structure of the underlying microscopic theory. A particularly rich topological structure, with 6 distinct terms, is uncovered for the model based on $SO(6)/SO(4)$, containing 2 Higgs doublets and a singlet. Of the corresponding couplings, one is an integer and one is a phase.
[ { "created": "Mon, 13 Aug 2018 11:27:08 GMT", "version": "v1" }, { "created": "Wed, 28 Nov 2018 15:09:04 GMT", "version": "v2" } ]
2018-12-26
[ [ "Davighi", "Joe", "" ], [ "Gripaios", "Ben", "" ] ]
We apply a recent classification of topological action terms to Composite Higgs models based on a variety of coset spaces $G/H$ and discuss their phenomenology. The topological terms, which can all be obtained by integrating (possibly only locally-defined) differential forms, come in one of two types, with substantially differing consequences for phenomenology. The first type of term (which appears in the minimal model based on $SO(5)/SO(4)$) is a field theory generalization of the Aharonov-Bohm phase in quantum mechanics. The phenomenological effects of such a term arise only at the non-perturbative level, and lead to $P$ and $CP$ violation in the Higgs sector. The second type of term (which appears in the model based on $SO(6)/SO(5)$) is a field theory generalization of the Dirac monopole in quantum mechanics and has physical effects even at the classical level. Perhaps most importantly, measuring the coefficient of such a term can allow one to probe the structure of the underlying microscopic theory. A particularly rich topological structure, with 6 distinct terms, is uncovered for the model based on $SO(6)/SO(4)$, containing 2 Higgs doublets and a singlet. Of the corresponding couplings, one is an integer and one is a phase.
1912.10353
Bernard Pire
Bernard Pire, Lech Szymanowski, Samuel Wallon
Diffractive deeply virtual Compton scattering
5 pages, 3 figures. published in Phys. Rev. D 101 , 074005 (2020). v2 includes changes described in the erratum published in PHYSICAL REVIEW D 103, 059901(E) (2021)
Phys. Rev. D 101, 074005 (2020)
10.1103/PhysRevD.101.074005
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Diffractive deeply virtual Compton scattering (DiDVCS) is the process $\gamma^*(- Q^2) + N \rightarrow \rho^0 + \gamma^* (Q'^2)+ N'$, where N is a nucleon or light nucleus, in the kinematical regime of large rapidity gap between the $\rho^0$ and the final photon-nucleus system, and in the generalized Bjorken regime where both photon virtualities $Q^2$ and $ Q'^2$ are large. We show that this process has the unique virtue of combining the large diffractive cross sections at high energy with the tomographic ability of deeply virtual Compton scattering to scrutinize the quark and gluon content of nucleons and light nuclei. Its study at an electron-ion collider would enlighten the internal structure of hadrons.
[ { "created": "Sat, 21 Dec 2019 22:38:29 GMT", "version": "v1" }, { "created": "Tue, 23 Mar 2021 08:07:25 GMT", "version": "v2" } ]
2021-03-24
[ [ "Pire", "Bernard", "" ], [ "Szymanowski", "Lech", "" ], [ "Wallon", "Samuel", "" ] ]
Diffractive deeply virtual Compton scattering (DiDVCS) is the process $\gamma^*(- Q^2) + N \rightarrow \rho^0 + \gamma^* (Q'^2)+ N'$, where N is a nucleon or light nucleus, in the kinematical regime of large rapidity gap between the $\rho^0$ and the final photon-nucleus system, and in the generalized Bjorken regime where both photon virtualities $Q^2$ and $ Q'^2$ are large. We show that this process has the unique virtue of combining the large diffractive cross sections at high energy with the tomographic ability of deeply virtual Compton scattering to scrutinize the quark and gluon content of nucleons and light nuclei. Its study at an electron-ion collider would enlighten the internal structure of hadrons.
hep-ph/0505201
Dmitri Diakonov
Dmitri Diakonov and Victor Petrov
Estimate of the Theta+ width in the Relativistic Mean Field Approximation
25 pp., 11 figs, minor corrections
Phys.Rev.D72:074009,2005
10.1103/PhysRevD.72.074009
null
hep-ph
null
In the Relativistic Mean Field Approximation three quarks in baryons from the lowest octet and the decuplet are bound by the self-consistent chiral field, and there are additional quark-antiquark pairs whose wave function also follows from the mean field. We present a generating functional for the 3-quark, 5-quark, 7-quark ... wave functions inside the octet, decuplet and antidecuplet baryons treated in a universal and compact way. The 3-quark components have the SU(6)-symmetric wave functions but with specific relativistic corrections which are generally not small. In particular, the normalization of the 5-quark component in the nucleon is about 50% of the 3-quark component. We give explicitly the 5-quark wave functions of the nucleon and of the exotic Theta+. We develop a formalism how to compute observables related to the 3- and 5-quark Fock components of baryons, and apply it to estimate the Theta+ width which turns out to be very small, 2-4 MeV, although with a large uncertainty.
[ { "created": "Mon, 23 May 2005 18:52:36 GMT", "version": "v1" }, { "created": "Wed, 8 Jun 2005 15:27:14 GMT", "version": "v2" } ]
2010-11-19
[ [ "Diakonov", "Dmitri", "" ], [ "Petrov", "Victor", "" ] ]
In the Relativistic Mean Field Approximation three quarks in baryons from the lowest octet and the decuplet are bound by the self-consistent chiral field, and there are additional quark-antiquark pairs whose wave function also follows from the mean field. We present a generating functional for the 3-quark, 5-quark, 7-quark ... wave functions inside the octet, decuplet and antidecuplet baryons treated in a universal and compact way. The 3-quark components have the SU(6)-symmetric wave functions but with specific relativistic corrections which are generally not small. In particular, the normalization of the 5-quark component in the nucleon is about 50% of the 3-quark component. We give explicitly the 5-quark wave functions of the nucleon and of the exotic Theta+. We develop a formalism how to compute observables related to the 3- and 5-quark Fock components of baryons, and apply it to estimate the Theta+ width which turns out to be very small, 2-4 MeV, although with a large uncertainty.
2304.04793
Peera Simakachorn
Anish Ghoshal, Yann Gouttenoire, Lucien Heurtier and Peera Simakachorn
Primordial Black Hole Archaeology with Gravitational Waves from Cosmic Strings
21 pages, 9 figures (main text without references) + 4 pages, 3 figures (appendices). Version published in JHEP
JHEP 08 (2023) 196
10.1007/JHEP08(2023)196
IPPP/23/13
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Light primordial black holes (PBHs) with masses smaller than $10^9$ g ($10^{-24} M_\odot$) evaporate before the onset of Big-Bang nucleosynthesis, rendering their detection rather challenging. If efficiently produced, they may have dominated the universe energy density. We study how such an early matter-dominated era can be probed successfully using gravitational waves (GW) emitted by local and global cosmic strings. While previous studies showed that a matter era generates a single-step suppression of the GW spectrum, we instead find a "double-step" suppression for local-string GW whose spectral shape provides information on the duration of the matter era. The presence of the two steps in the GW spectrum originates from GW being produced through two events separated in time: loop formation and loop decay, taking place either before or after the matter era. The second step - called the "knee" - is a novel feature which is universal to any early matter-dominated era and is not only specific to PBHs. Detecting GWs from cosmic strings with LISA, ET, or BBO would set constraints on PBHs with masses between $10^6$ and $10^9$ g for local strings with tension $G\mu = 10^{-11}$, and PBHs masses between $10^4$ and $10^9$ g for global strings with symmetry-breaking scale $\eta = 10^{15}~\mathrm{GeV}$. Effects from the spin of PBHs are discussed.
[ { "created": "Mon, 10 Apr 2023 18:00:13 GMT", "version": "v1" }, { "created": "Thu, 31 Aug 2023 22:12:19 GMT", "version": "v2" } ]
2023-09-04
[ [ "Ghoshal", "Anish", "" ], [ "Gouttenoire", "Yann", "" ], [ "Heurtier", "Lucien", "" ], [ "Simakachorn", "Peera", "" ] ]
Light primordial black holes (PBHs) with masses smaller than $10^9$ g ($10^{-24} M_\odot$) evaporate before the onset of Big-Bang nucleosynthesis, rendering their detection rather challenging. If efficiently produced, they may have dominated the universe energy density. We study how such an early matter-dominated era can be probed successfully using gravitational waves (GW) emitted by local and global cosmic strings. While previous studies showed that a matter era generates a single-step suppression of the GW spectrum, we instead find a "double-step" suppression for local-string GW whose spectral shape provides information on the duration of the matter era. The presence of the two steps in the GW spectrum originates from GW being produced through two events separated in time: loop formation and loop decay, taking place either before or after the matter era. The second step - called the "knee" - is a novel feature which is universal to any early matter-dominated era and is not only specific to PBHs. Detecting GWs from cosmic strings with LISA, ET, or BBO would set constraints on PBHs with masses between $10^6$ and $10^9$ g for local strings with tension $G\mu = 10^{-11}$, and PBHs masses between $10^4$ and $10^9$ g for global strings with symmetry-breaking scale $\eta = 10^{15}~\mathrm{GeV}$. Effects from the spin of PBHs are discussed.
hep-ph/0305095
Roberto Martinez
John Morales, R. Martinez, Rodolfo A. Diaz, Rafael Hurtado
Higgs boson decay in the large N limit
20 pages, Title changed, input parameters updated, version to appear in the Brazilian Journal of Physics
Braz.J.Phys. 35 (2005) 597-606
null
null
hep-ph
null
The Equivalence Theorem is commonly used to calculate perturbatively amplitudes involving gauge bosons at energy scales higher than gauge boson masses. However, when the scalar sector is strongly interacting the theory is non-perturbative. We show that the Equivalence Theorem holds in the large N limit at next-to-leading order by calculating the decay widths h -> W^{+}W^{-} and h->\pi^{+}\pi^{-}. We also show, in the same scheme of calculations, that unitarity is fulfilled for the process h->\pi^{+}\pi^{-}.
[ { "created": "Fri, 9 May 2003 00:11:01 GMT", "version": "v1" }, { "created": "Mon, 27 Sep 2004 20:29:27 GMT", "version": "v2" }, { "created": "Fri, 10 Jun 2005 22:16:30 GMT", "version": "v3" } ]
2007-05-23
[ [ "Morales", "John", "" ], [ "Martinez", "R.", "" ], [ "Diaz", "Rodolfo A.", "" ], [ "Hurtado", "Rafael", "" ] ]
The Equivalence Theorem is commonly used to calculate perturbatively amplitudes involving gauge bosons at energy scales higher than gauge boson masses. However, when the scalar sector is strongly interacting the theory is non-perturbative. We show that the Equivalence Theorem holds in the large N limit at next-to-leading order by calculating the decay widths h -> W^{+}W^{-} and h->\pi^{+}\pi^{-}. We also show, in the same scheme of calculations, that unitarity is fulfilled for the process h->\pi^{+}\pi^{-}.
1111.5895
A. I. Milstein
R.N. Lee, A.I. Milstein, and V.M. Strakhovenko
Charge asymmetry in the differential cross section of high-energy e+e- photoproduction in the field of a heavy atom
19 pages, 7 figures
Physical Review A 85, 042104 (2012)
10.1103/PhysRevA.85.042104
null
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
First quasiclassical correction to the differential cross section of high-energy electron-positron photoproduction in the electric field of a heavy atom is obtained with the exact account of the field. This correction is responsible for the charge asymmetry ${\cal A}$ in this process. When the transverse momentum of at least one of the produced particles is much larger than the electron mass $m$, the charge asymmetry can be as large as tens percent. We also estimate the contribution $\tilde{\cal A}$ to the charge asymmetry coming from the Compton-type diagram. For heavy nuclei, this contribution is negligible. For light nuclei, $\tilde{\cal A}$ is noticeable only when the angle between the momenta of electron and positron is of order of $m/\omega$ ($\omega$ is the photon energy) while the transverse momenta of both particles are much larger than $m$.
[ { "created": "Fri, 25 Nov 2011 05:47:47 GMT", "version": "v1" } ]
2012-04-11
[ [ "Lee", "R. N.", "" ], [ "Milstein", "A. I.", "" ], [ "Strakhovenko", "V. M.", "" ] ]
First quasiclassical correction to the differential cross section of high-energy electron-positron photoproduction in the electric field of a heavy atom is obtained with the exact account of the field. This correction is responsible for the charge asymmetry ${\cal A}$ in this process. When the transverse momentum of at least one of the produced particles is much larger than the electron mass $m$, the charge asymmetry can be as large as tens percent. We also estimate the contribution $\tilde{\cal A}$ to the charge asymmetry coming from the Compton-type diagram. For heavy nuclei, this contribution is negligible. For light nuclei, $\tilde{\cal A}$ is noticeable only when the angle between the momenta of electron and positron is of order of $m/\omega$ ($\omega$ is the photon energy) while the transverse momenta of both particles are much larger than $m$.
hep-ph/9307226
null
G.F. Giudice and E. Roulet
Conditions on supersymmetry soft-breaking terms from GUTs
7 pages, CERN-TH.6940/93
Phys.Lett. B315 (1993) 107-112
10.1016/0370-2693(93)90165-E
null
hep-ph
null
We study the effect of integrating out the heavy fields in a supersymmetric GUT which does not contain small mass parameters in the limit of exact supersymmetry. The trilinear ($A$) and bilinear ($B$) coefficients of the supersymmetry soft-breaking terms of the low-energy effective theory are related in a simple and model-independent way to those of the underlying theory. {}From these relations, we obtain the bound $|B|\ge 2$, which, together with the requirements of stability of the potential and electroweak symmetry breaking, imposes severe constraints on the space of allowed supersymmetric parameters. In models based on supergravity with a flat K\"ahler metric, we obtain $B=2$, instead of the relation $B=A-1$ usually used in phenomenological applications. The low-energy theory contains also a supersymmetric mass term $\mu$ for the two Higgs doublets, which is of the order of the supersymmetry-breaking scale.
[ { "created": "Tue, 6 Jul 1993 17:53:36 GMT", "version": "v1" } ]
2009-10-22
[ [ "Giudice", "G. F.", "" ], [ "Roulet", "E.", "" ] ]
We study the effect of integrating out the heavy fields in a supersymmetric GUT which does not contain small mass parameters in the limit of exact supersymmetry. The trilinear ($A$) and bilinear ($B$) coefficients of the supersymmetry soft-breaking terms of the low-energy effective theory are related in a simple and model-independent way to those of the underlying theory. {}From these relations, we obtain the bound $|B|\ge 2$, which, together with the requirements of stability of the potential and electroweak symmetry breaking, imposes severe constraints on the space of allowed supersymmetric parameters. In models based on supergravity with a flat K\"ahler metric, we obtain $B=2$, instead of the relation $B=A-1$ usually used in phenomenological applications. The low-energy theory contains also a supersymmetric mass term $\mu$ for the two Higgs doublets, which is of the order of the supersymmetry-breaking scale.
hep-ph/0204039
Czyz Henryk
H.Czyz, A. Grzelinska, R. Zabawa
The analytical values of the sunrise master integrals for one of the masses equal to zero
null
Phys.Lett. B538 (2002) 52-58
10.1016/S0370-2693(02)01992-5
null
hep-ph
null
The analytical values of the sunrise master amplitudes were found for one mass equal to zero, two other arbitrary masses and an arbitrary external four momentum. Differential equations in the square of the external four momentum and masses were used to obtain the master integrals.
[ { "created": "Wed, 3 Apr 2002 15:44:26 GMT", "version": "v1" } ]
2015-06-25
[ [ "Czyz", "H.", "" ], [ "Grzelinska", "A.", "" ], [ "Zabawa", "R.", "" ] ]
The analytical values of the sunrise master amplitudes were found for one mass equal to zero, two other arbitrary masses and an arbitrary external four momentum. Differential equations in the square of the external four momentum and masses were used to obtain the master integrals.
2308.14825
Sebastian Grieninger
Sebastian Grieninger, Dmitri E. Kharzeev
Spacetime dynamics of chiral magnetic currents in a hot non-Abelian plasma
9+1 pages, 6+2 figures; matches version published in PRD; title change to conform with APS conventions
Phys. Rev. D 108, 126004 (2023)
10.1103/PhysRevD.108.126004
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The correlations of electric currents in hot non-Abelian plasma are responsible for the experimental manifestations of the chiral magnetic effect (CME) in heavy-ion collisions. We evaluate these correlations using holography, and show that they are driven by large-scale topological fluctuations. In a non-Abelian plasma with chiral fermions, local axial charge can be generated either by topological fluctuations (creating domains with nonzero Chern-Simons number) or by thermal fluctuations. Within holography, we investigate the dynamical creation of the axial charge and isolate the imprint of the topological dynamics on the spatial correlations of electric current. In particular, we show that the spatial extent of the current correlation is quite large ($\sim 1\ {\rm fm}$) and grows with time, which is consistent with sphaleronlike dynamics. We provide numerical estimates for this spatial size that can be used as an input in phenomenological analyses.
[ { "created": "Mon, 28 Aug 2023 18:22:28 GMT", "version": "v1" }, { "created": "Sun, 17 Dec 2023 18:56:02 GMT", "version": "v2" } ]
2023-12-19
[ [ "Grieninger", "Sebastian", "" ], [ "Kharzeev", "Dmitri E.", "" ] ]
The correlations of electric currents in hot non-Abelian plasma are responsible for the experimental manifestations of the chiral magnetic effect (CME) in heavy-ion collisions. We evaluate these correlations using holography, and show that they are driven by large-scale topological fluctuations. In a non-Abelian plasma with chiral fermions, local axial charge can be generated either by topological fluctuations (creating domains with nonzero Chern-Simons number) or by thermal fluctuations. Within holography, we investigate the dynamical creation of the axial charge and isolate the imprint of the topological dynamics on the spatial correlations of electric current. In particular, we show that the spatial extent of the current correlation is quite large ($\sim 1\ {\rm fm}$) and grows with time, which is consistent with sphaleronlike dynamics. We provide numerical estimates for this spatial size that can be used as an input in phenomenological analyses.
2207.04516
Pablo Mart\'inez-Mirav\'e
Evgeny Akhmedov and Pablo Mart\'inez-Mirav\'e
Solar $\bar{\nu}_e$ flux: Revisiting bounds on neutrino magnetic moments and solar magnetic field
34 pages, 7 figures, 5 tables. Matches the published version
JHEP 10 (2022) 144
10.1007/JHEP10(2022)144
null
hep-ph astro-ph.SR hep-ex
http://creativecommons.org/licenses/by/4.0/
The interaction of neutrino transition magnetic dipole moments with magnetic fields can give rise to the phenomenon of neutrino spin-flavour precession (SFP). For Majorana neutrinos, the combined action of SFP of solar neutrinos and flavour oscillations would manifest itself as a small, yet potentially detectable, flux of electron antineutrinos coming from the Sun. Non-observation of such a flux constrains the product of the neutrino magnetic moment $\mu$ and the strength of the solar magnetic field $B$. We derive a simple analytical expression for the expected $\bar{\nu}_e$ appearance probability in the three-flavour framework and we use it to revisit the existing experimental bounds on $\mu B$. A full numerical calculation has also been performed to check the validity of the analytical result. We also present our numerical results in energy-binned form, convenient for analyses of the data of the current and future experiments searching for the solar $\bar{\nu}_e$ flux. In addition, we give a comprehensive compilation of other existing limits on neutrino magnetic moments and of the expressions for the probed effective magnetic moments in terms of the fundamental neutrino magnetic moments and leptonic mixing parameters.
[ { "created": "Sun, 10 Jul 2022 18:51:31 GMT", "version": "v1" }, { "created": "Wed, 17 Aug 2022 14:29:32 GMT", "version": "v2" }, { "created": "Thu, 18 Aug 2022 17:33:34 GMT", "version": "v3" }, { "created": "Wed, 26 Oct 2022 16:00:06 GMT", "version": "v4" } ]
2022-10-27
[ [ "Akhmedov", "Evgeny", "" ], [ "Martínez-Miravé", "Pablo", "" ] ]
The interaction of neutrino transition magnetic dipole moments with magnetic fields can give rise to the phenomenon of neutrino spin-flavour precession (SFP). For Majorana neutrinos, the combined action of SFP of solar neutrinos and flavour oscillations would manifest itself as a small, yet potentially detectable, flux of electron antineutrinos coming from the Sun. Non-observation of such a flux constrains the product of the neutrino magnetic moment $\mu$ and the strength of the solar magnetic field $B$. We derive a simple analytical expression for the expected $\bar{\nu}_e$ appearance probability in the three-flavour framework and we use it to revisit the existing experimental bounds on $\mu B$. A full numerical calculation has also been performed to check the validity of the analytical result. We also present our numerical results in energy-binned form, convenient for analyses of the data of the current and future experiments searching for the solar $\bar{\nu}_e$ flux. In addition, we give a comprehensive compilation of other existing limits on neutrino magnetic moments and of the expressions for the probed effective magnetic moments in terms of the fundamental neutrino magnetic moments and leptonic mixing parameters.
1512.08176
Sayantan Choudhury
Sayantan Choudhury, Manibrata Sen, Soumya Sadhukhan
Can Dark Matter be an artifact of extended theories of gravity?
45 pages, 8 figures, Accepted for publication in European Physical Journal C
Eur. Phys. J. C 76 (2016) no.9, 494
10.1140/epjc/s10052-016-4323-2
TIFR/TH/15-46
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we propose different background models of extended theories of gravity, which are minimally coupled to the SM fields, to explain the possibility of genesis of dark matter without affecting the SM particle sector. We modify the gravity sector by allowing quantum corrections motivated from (1) local $f(R)$ gravity and (2) non-minimally coupled gravity with SM sector and dilaton field. Next we apply conformal transformation on the metric to transform the action back to the Einstein frame. We also show that an effective theory constructed from these extended theories of gravity and SM sector looks exactly the same. Using the relic constraint observed by Planck 2015, we constrain the scale of the effective field theory ($\Lambda_{UV}$) as well as the dark matter mass ($M$). We consider two cases- (1) light dark matter (LDM) and (2) heavy dark matter (HDM), and deduce upper bounds on thermally averaged cross section of dark matter annihilating to SM particles. Further we show that our model naturally incorporates self interactions of dark matter. Using these self interactions, we derive the constraints on the parameters of the (1) local $f(R)$ gravity and (2) non-minimally coupled gravity from dark matter self interaction. Finally, we propose some different UV complete models from a particle physics point of view, which can give rise to the same effective theory that we have deduced from extended theories of gravity.
[ { "created": "Sun, 27 Dec 2015 06:45:11 GMT", "version": "v1" }, { "created": "Thu, 28 Apr 2016 09:57:07 GMT", "version": "v2" }, { "created": "Thu, 18 Aug 2016 11:33:15 GMT", "version": "v3" } ]
2016-09-14
[ [ "Choudhury", "Sayantan", "" ], [ "Sen", "Manibrata", "" ], [ "Sadhukhan", "Soumya", "" ] ]
In this article, we propose different background models of extended theories of gravity, which are minimally coupled to the SM fields, to explain the possibility of genesis of dark matter without affecting the SM particle sector. We modify the gravity sector by allowing quantum corrections motivated from (1) local $f(R)$ gravity and (2) non-minimally coupled gravity with SM sector and dilaton field. Next we apply conformal transformation on the metric to transform the action back to the Einstein frame. We also show that an effective theory constructed from these extended theories of gravity and SM sector looks exactly the same. Using the relic constraint observed by Planck 2015, we constrain the scale of the effective field theory ($\Lambda_{UV}$) as well as the dark matter mass ($M$). We consider two cases- (1) light dark matter (LDM) and (2) heavy dark matter (HDM), and deduce upper bounds on thermally averaged cross section of dark matter annihilating to SM particles. Further we show that our model naturally incorporates self interactions of dark matter. Using these self interactions, we derive the constraints on the parameters of the (1) local $f(R)$ gravity and (2) non-minimally coupled gravity from dark matter self interaction. Finally, we propose some different UV complete models from a particle physics point of view, which can give rise to the same effective theory that we have deduced from extended theories of gravity.
hep-ph/0401063
Nikolai Uraltsev
Paolo Gambino and Nikolai Uraltsev
Moments of semileptonic B decay distributions in the 1/m_b expansion
16 pages, LaTeX, three figures
Eur.Phys.J.C34:181-189,2004
10.1140/epjc/s2004-01671-2
Bicocca-FT-03-34, UND-HEP-03-BIG08
hep-ph
null
We report the OPE-based predictions for a number of lepton energy and hadronic mass moments in the inclusive semileptonic B -> X_c \ell\nu decays with a lower cut on the charged lepton energy. We rely on the direct OPE approach where no expansion in the charm mass is employed and the theoretical input is a limited set of underlying OPE parameters including m_b and m_c. A Wilsonian treatment with a `hard' cutoff is applied using running low-scale masses m_Q(\mu) and kinetic expectation value \mu_\pi^2(\mu). This leaves for perturbative corrections only genuinely short-distance effects and makes them numerically small. Predictions are also given for the modified hadronic moments of the kinematic variable \cal N_X^2 which is a combination of M_X^2 and E_X. Measurement of such moments would allow a more reliable extraction of higher-order nonperturbative heavy quark parameters from experiment.
[ { "created": "Sun, 11 Jan 2004 20:34:48 GMT", "version": "v1" } ]
2014-11-17
[ [ "Gambino", "Paolo", "" ], [ "Uraltsev", "Nikolai", "" ] ]
We report the OPE-based predictions for a number of lepton energy and hadronic mass moments in the inclusive semileptonic B -> X_c \ell\nu decays with a lower cut on the charged lepton energy. We rely on the direct OPE approach where no expansion in the charm mass is employed and the theoretical input is a limited set of underlying OPE parameters including m_b and m_c. A Wilsonian treatment with a `hard' cutoff is applied using running low-scale masses m_Q(\mu) and kinetic expectation value \mu_\pi^2(\mu). This leaves for perturbative corrections only genuinely short-distance effects and makes them numerically small. Predictions are also given for the modified hadronic moments of the kinematic variable \cal N_X^2 which is a combination of M_X^2 and E_X. Measurement of such moments would allow a more reliable extraction of higher-order nonperturbative heavy quark parameters from experiment.
hep-ph/0405244
Bob McElrath
Tao Han, Paul Langacker, Bob McElrath
The Higgs Sector in a $U(1)^\prime$ Extension of the MSSM
49 pages, 17 figures
Phys.Rev. D70 (2004) 115006
10.1103/PhysRevD.70.115006
MADPH-04-1376; UPR-1043T; UCD-2004-20
hep-ph hep-ex
null
We consider the Higgs sector in an extension of the MSSM with extra SM singlets, involving an extra $U(1)^\prime$ gauge symmetry, in which the domain-wall problem is avoided and the effective $\mu$ parameter is decoupled from the new gauge boson $Z^\prime$ mass. The model involves a rich Higgs structure very different from that of the MSSM. In particular, there are large mixings between Higgs doublets and the SM singlets, significantly affecting the Higgs spectrum, production cross sections, decay modes, existing exclusion limits, and allowed parameter range. Scalars considerably lighter than the LEP2 bound (114 GeV) are allowed, and the range $\tan \beta \sim 1$ is both allowed and theoretically favored. Phenomenologically, we concentrate our study on the lighter (least model-dependent, yet characteristic) Higgs particles with significant SU(2)-doublet components to their wave functions, for the case of no explicit CP violation in the Higgs sector. We consider their spectra, including the dominant radiative corrections to their masses from the top/stop loop. We computed their production cross sections and reexamine the existing exclusion limits at LEP2. We outline the searching strategy for some representative scenarios at a future linear collider. We emphasize that gaugino, Higgsino, and singlino decay modes are indicative of extended models and have been given little attention. We present a comprehensive list of model scenarios in the Appendices.
[ { "created": "Tue, 25 May 2004 18:05:43 GMT", "version": "v1" }, { "created": "Tue, 8 Jun 2004 02:56:09 GMT", "version": "v2" } ]
2009-11-10
[ [ "Han", "Tao", "" ], [ "Langacker", "Paul", "" ], [ "McElrath", "Bob", "" ] ]
We consider the Higgs sector in an extension of the MSSM with extra SM singlets, involving an extra $U(1)^\prime$ gauge symmetry, in which the domain-wall problem is avoided and the effective $\mu$ parameter is decoupled from the new gauge boson $Z^\prime$ mass. The model involves a rich Higgs structure very different from that of the MSSM. In particular, there are large mixings between Higgs doublets and the SM singlets, significantly affecting the Higgs spectrum, production cross sections, decay modes, existing exclusion limits, and allowed parameter range. Scalars considerably lighter than the LEP2 bound (114 GeV) are allowed, and the range $\tan \beta \sim 1$ is both allowed and theoretically favored. Phenomenologically, we concentrate our study on the lighter (least model-dependent, yet characteristic) Higgs particles with significant SU(2)-doublet components to their wave functions, for the case of no explicit CP violation in the Higgs sector. We consider their spectra, including the dominant radiative corrections to their masses from the top/stop loop. We computed their production cross sections and reexamine the existing exclusion limits at LEP2. We outline the searching strategy for some representative scenarios at a future linear collider. We emphasize that gaugino, Higgsino, and singlino decay modes are indicative of extended models and have been given little attention. We present a comprehensive list of model scenarios in the Appendices.
hep-ph/0205292
Mizuno Shuntaro
Shuntaro Mizuno, Kei-ichi Maeda, Kohta Yamamoto
Dynamics of Scalar field in a Brane World
15pages, 8figures, submitted to Physical Review D
Phys.Rev. D67 (2003) 023516
10.1103/PhysRevD.67.023516
WU-AP/147/02
hep-ph astro-ph gr-qc hep-th
null
We study the dynamics of a scalar field in the brane cosmology. We assume that a scalar field is confined in our 4-dimensional world. As for the potential of the scalar field, we discuss three typical models: (1) a power-law potential, (2) an inverse-power-law potential, and (3) an exponential potential. We show that the behavior of the scalar field is very different from a conventional cosmology when the energy density square term is dominated.
[ { "created": "Sat, 25 May 2002 10:36:51 GMT", "version": "v1" } ]
2009-11-07
[ [ "Mizuno", "Shuntaro", "" ], [ "Maeda", "Kei-ichi", "" ], [ "Yamamoto", "Kohta", "" ] ]
We study the dynamics of a scalar field in the brane cosmology. We assume that a scalar field is confined in our 4-dimensional world. As for the potential of the scalar field, we discuss three typical models: (1) a power-law potential, (2) an inverse-power-law potential, and (3) an exponential potential. We show that the behavior of the scalar field is very different from a conventional cosmology when the energy density square term is dominated.
2201.07808
Qiang Li
Sitian Qian, Zhe Guan, Sen Deng, Yunxuan Song, Tianyu Mu, Jie Xiao, Tianyi Yang, Siguang Wang, Yajun Mao, Qiang Li, Meng Lu, Zhengyun You
Boosted tau lepton as a microscope and macroscope
6 pages, 5 figures; updated version to match the accepted one in Advances in High Energy Physics
null
null
null
hep-ph astro-ph.HE hep-ex
http://creativecommons.org/licenses/by/4.0/
Anomalies from the LHCb lepton flavour universality and Fermilab muon anomalous magnetic momentum, show tantalizing hints of possible new physics from the lepton sectors. Due to its large mass and shorter lifetime than muon, the tau lepton is believed to couple more to possible new physics beyond the standard model. Traditionally, tau leptons are probed through the decay products due to tau's short life time. On the other hand, at a high energy scale, a large fraction of tau leptons could be boosted to a much longer life time and fly a visible distance from several centimetres up to kilometer length scale, yet very informative to new physics beyond the standard model or high energy cosmic rays. In this article, we show unique yet promising tau physics by exploiting long-lived taus as a microscope or macroscope, to measure tau's anomalous magnetic momentum to an unprecedented level of accuracy and detect high energy cosmic neutrinos at the 1 TeV to 1 PeV scale, respectively.
[ { "created": "Wed, 19 Jan 2022 19:00:04 GMT", "version": "v1" }, { "created": "Fri, 26 Aug 2022 01:32:27 GMT", "version": "v2" } ]
2022-08-29
[ [ "Qian", "Sitian", "" ], [ "Guan", "Zhe", "" ], [ "Deng", "Sen", "" ], [ "Song", "Yunxuan", "" ], [ "Mu", "Tianyu", "" ], [ "Xiao", "Jie", "" ], [ "Yang", "Tianyi", "" ], [ "Wang", "Siguang", "" ], [ "Mao", "Yajun", "" ], [ "Li", "Qiang", "" ], [ "Lu", "Meng", "" ], [ "You", "Zhengyun", "" ] ]
Anomalies from the LHCb lepton flavour universality and Fermilab muon anomalous magnetic momentum, show tantalizing hints of possible new physics from the lepton sectors. Due to its large mass and shorter lifetime than muon, the tau lepton is believed to couple more to possible new physics beyond the standard model. Traditionally, tau leptons are probed through the decay products due to tau's short life time. On the other hand, at a high energy scale, a large fraction of tau leptons could be boosted to a much longer life time and fly a visible distance from several centimetres up to kilometer length scale, yet very informative to new physics beyond the standard model or high energy cosmic rays. In this article, we show unique yet promising tau physics by exploiting long-lived taus as a microscope or macroscope, to measure tau's anomalous magnetic momentum to an unprecedented level of accuracy and detect high energy cosmic neutrinos at the 1 TeV to 1 PeV scale, respectively.
1804.05357
Sreerup Raychaudhuri
Disha Bhatia, Ushoshi Maitra, Sreerup Raychaudhuri
Pinning down Anomalous $WW\gamma$ Couplings at the LHC
References updated
Phys. Rev. D 99, 095017 (2019)
10.1103/PhysRevD.99.095017
TIFR-TH/18-9
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We make a careful analysis of $W^\pm\gamma$ production at the LHC, identifying the $W^\pm$ through leptonic decays, with a view to exploring the sensitivity of the machine to anomalous $CP$-conserving $WW\gamma$ interactions. All the available kinematic variables are used, but we find that the most useful one is the opening angle in the transverse plane between the decay products of the $W^\pm$. It is shown that even a simple-minded analysis using this variable can lead to a much greater sensitivity at the LHC than the current constraints on the relevant parameters.
[ { "created": "Sun, 15 Apr 2018 13:20:19 GMT", "version": "v1" }, { "created": "Mon, 21 May 2018 15:10:28 GMT", "version": "v2" } ]
2019-05-22
[ [ "Bhatia", "Disha", "" ], [ "Maitra", "Ushoshi", "" ], [ "Raychaudhuri", "Sreerup", "" ] ]
We make a careful analysis of $W^\pm\gamma$ production at the LHC, identifying the $W^\pm$ through leptonic decays, with a view to exploring the sensitivity of the machine to anomalous $CP$-conserving $WW\gamma$ interactions. All the available kinematic variables are used, but we find that the most useful one is the opening angle in the transverse plane between the decay products of the $W^\pm$. It is shown that even a simple-minded analysis using this variable can lead to a much greater sensitivity at the LHC than the current constraints on the relevant parameters.
hep-ph/0703025
Peter Schweitzer
C. Cebulla, K. Goeke, J. Ossmann, P. Schweitzer
The nucleon form-factors of the energy momentum tensor in the Skyrme model
19 pages, 11 Figures, 2 Tables; correction in footnote 2, extension in App.D, some reformulations, references added, results and conclusions unchanged
Nucl.Phys.A794:87-114,2007
10.1016/j.nuclphysa.2007.08.004
RUB-TP2-01-2007
hep-ph
null
The nucleon form factors of the energy-momentum tensor are studied in the large-Nc limit in the framework of the Skyrme model.
[ { "created": "Fri, 2 Mar 2007 16:31:35 GMT", "version": "v1" }, { "created": "Fri, 21 Sep 2007 07:44:43 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cebulla", "C.", "" ], [ "Goeke", "K.", "" ], [ "Ossmann", "J.", "" ], [ "Schweitzer", "P.", "" ] ]
The nucleon form factors of the energy-momentum tensor are studied in the large-Nc limit in the framework of the Skyrme model.
0904.1090
Gabor Cynolter
G. Cynolter, E. Lendvai and G. Pocsik
S and T Parameters in the Fermion Condensate Model
14 pages, 5 figures
Mod.Phys.Lett.A24:2331-2344,2009
10.1142/S0217732309031594
ITP-Budapest 644
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the oblique electroweak corrections and confront them with the experiments in a composite Higgs version of the standard model. A vector-like weak doublet and a singlet fermion are added to the standard model without elementary Higgs. Due to quartic coupling there is a mixing between the components of the new fields triggering electroweak symmetry breaking. The Peskin-Takeuchi S and T electroweak parameters are presented. The new sector of vector-like fermions is slightly constrained, T gives an upper bound on the mixing angle of the new fermions, which is already constrained by self-consistent gap-equations. S gives no constraints on the masses. This extension can give a positive contribution to T, allowing for a heavy Higgs boson in electroweak precision tests of the Standard Model.
[ { "created": "Tue, 7 Apr 2009 09:36:41 GMT", "version": "v1" } ]
2009-11-18
[ [ "Cynolter", "G.", "" ], [ "Lendvai", "E.", "" ], [ "Pocsik", "G.", "" ] ]
We calculate the oblique electroweak corrections and confront them with the experiments in a composite Higgs version of the standard model. A vector-like weak doublet and a singlet fermion are added to the standard model without elementary Higgs. Due to quartic coupling there is a mixing between the components of the new fields triggering electroweak symmetry breaking. The Peskin-Takeuchi S and T electroweak parameters are presented. The new sector of vector-like fermions is slightly constrained, T gives an upper bound on the mixing angle of the new fermions, which is already constrained by self-consistent gap-equations. S gives no constraints on the masses. This extension can give a positive contribution to T, allowing for a heavy Higgs boson in electroweak precision tests of the Standard Model.
1302.6462
Sergio Scopetta
M. Rinaldi, S. Scopetta, V. Vento
Double parton correlations in constituent quark models
16 pages, 7 figures; references added; a figure added; conclusions unchanged. Final version accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.87.114021
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Double parton correlations, having effects on the double parton scattering processes occurring in high-energy hadron-hadron collisions, for example at the LHC, are studied in the valence quark region, within constituent quark models. In this framework, two particle correlations are present without any additional prescription, at variance with what happens, for example, in independent particle models, such as the MIT bag model in its simplest version. From the present analysis, conclusions similar to the ones obtained recenty in a modified version of the bag model can be drawn: correlations in the longitudinal momenta of the active quarks are found to be sizable, while those in transverse momentum are much smaller. However, the used framework allows to understand clearly the dynamical origin of the correlations. In particular, it is shown that the small size of the correlations in transverse momentum is a model dependent result, which would not occur if models with sizable quark orbital angular momentum were used to describe the proton. Our analysis permits therefore to clarify the dynamical origin of the double parton correlations and to establish which, among the features of the results, are model independent. The possibility to test experimentally the studied effects is discussed.
[ { "created": "Tue, 26 Feb 2013 15:46:30 GMT", "version": "v1" }, { "created": "Fri, 8 Mar 2013 16:41:40 GMT", "version": "v2" }, { "created": "Mon, 17 Jun 2013 15:10:47 GMT", "version": "v3" } ]
2015-06-15
[ [ "Rinaldi", "M.", "" ], [ "Scopetta", "S.", "" ], [ "Vento", "V.", "" ] ]
Double parton correlations, having effects on the double parton scattering processes occurring in high-energy hadron-hadron collisions, for example at the LHC, are studied in the valence quark region, within constituent quark models. In this framework, two particle correlations are present without any additional prescription, at variance with what happens, for example, in independent particle models, such as the MIT bag model in its simplest version. From the present analysis, conclusions similar to the ones obtained recenty in a modified version of the bag model can be drawn: correlations in the longitudinal momenta of the active quarks are found to be sizable, while those in transverse momentum are much smaller. However, the used framework allows to understand clearly the dynamical origin of the correlations. In particular, it is shown that the small size of the correlations in transverse momentum is a model dependent result, which would not occur if models with sizable quark orbital angular momentum were used to describe the proton. Our analysis permits therefore to clarify the dynamical origin of the double parton correlations and to establish which, among the features of the results, are model independent. The possibility to test experimentally the studied effects is discussed.
2011.09347
Kai Schmitz
Valerie Domcke, Kohei Kamada, Kyohei Mukaida, Kai Schmitz, Masaki Yamada
Wash-In Leptogenesis
5 pages + references and appendix, 1 figure, 2 tables. v2: matches version published in PRL
Phys. Rev. Lett. 126, 201802 (2021)
10.1103/PhysRevLett.126.201802
CERN-TH-2020-196, RESCEU-22/20, DESY 20-202, TU-1112
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
We present a leptogenesis mechanism based on the standard type-I seesaw model that successfully operates at right-handed-neutrino masses as low as a few 100 TeV. This mechanism, which we dub "wash-in leptogenesis", does not require any CP violation in the neutrino sector and can be implemented even in the regime of strong wash-out. The key idea behind wash-in leptogenesis is to generalize standard freeze-out leptogenesis to a nonminimal cosmological background in which the chemical potentials of all particles not in chemical equilibrium at the temperature of leptogenesis are allowed to take arbitrary values. This sets the stage for building a plethora of new baryogenesis models where chemical potentials generated at high temperatures are reprocessed to generate a nonvanishing B-L asymmetry at low temperatures. As concrete examples, we discuss wash-in leptogenesis after axion inflation and in the context of grand unification.
[ { "created": "Wed, 18 Nov 2020 15:32:18 GMT", "version": "v1" }, { "created": "Thu, 20 May 2021 16:22:53 GMT", "version": "v2" } ]
2021-05-21
[ [ "Domcke", "Valerie", "" ], [ "Kamada", "Kohei", "" ], [ "Mukaida", "Kyohei", "" ], [ "Schmitz", "Kai", "" ], [ "Yamada", "Masaki", "" ] ]
We present a leptogenesis mechanism based on the standard type-I seesaw model that successfully operates at right-handed-neutrino masses as low as a few 100 TeV. This mechanism, which we dub "wash-in leptogenesis", does not require any CP violation in the neutrino sector and can be implemented even in the regime of strong wash-out. The key idea behind wash-in leptogenesis is to generalize standard freeze-out leptogenesis to a nonminimal cosmological background in which the chemical potentials of all particles not in chemical equilibrium at the temperature of leptogenesis are allowed to take arbitrary values. This sets the stage for building a plethora of new baryogenesis models where chemical potentials generated at high temperatures are reprocessed to generate a nonvanishing B-L asymmetry at low temperatures. As concrete examples, we discuss wash-in leptogenesis after axion inflation and in the context of grand unification.
2105.04464
Qing-Hong Cao
Qing-Hong Cao, Hao-ran Jiang, Guojin Zeng
Single Top Quark Production with and without a Higgs Boson
null
null
10.1088/1674-1137/ac0e8b
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
One way to probe new physics beyond standard model is to check the correlation among higher dimension operators in effective field theory. We examine the strong correlation between the processes of $pp\rightarrow tHq$ and $pp\rightarrow tq$ which both depend on the same three operators. The correlation indicates that, according to the data of $pp\rightarrow tq$, $\sigma_{tHq}=\big[106.8 \pm 64.8\big]~{\rm fb}$ which is far below the current upper limit $\sigma_{tHq}\leq 900~{\rm fb}$.
[ { "created": "Mon, 10 May 2021 15:59:42 GMT", "version": "v1" }, { "created": "Thu, 20 May 2021 13:05:37 GMT", "version": "v2" } ]
2021-09-22
[ [ "Cao", "Qing-Hong", "" ], [ "Jiang", "Hao-ran", "" ], [ "Zeng", "Guojin", "" ] ]
One way to probe new physics beyond standard model is to check the correlation among higher dimension operators in effective field theory. We examine the strong correlation between the processes of $pp\rightarrow tHq$ and $pp\rightarrow tq$ which both depend on the same three operators. The correlation indicates that, according to the data of $pp\rightarrow tq$, $\sigma_{tHq}=\big[106.8 \pm 64.8\big]~{\rm fb}$ which is far below the current upper limit $\sigma_{tHq}\leq 900~{\rm fb}$.
2108.10331
Vazha Loladze
Emilie Bertholet, Sabyasachi Chakraborty, Vazha Loladze, Takemichi Okui, Abner Soffer, Kohsaku Tobioka
Heavy QCD Axion at Belle II: Displaced and Prompt Signals
7 pages, 4 figures; Version accepted for publication in PRD Letter, including experimental results published after version-1 that imply new limits on the axion parameters
null
10.1103/PhysRevD.105.L071701
KEK-TH-2343
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The QCD axion is a well-motivated addition to the standard model to solve the strong $C\!P$ problem. If the axion acquires mass dominantly from a hidden sector, it can be as heavy as $O(1)$ GeV, and the decay constant can be as low as $O(100)$ GeV without running into the axion quality problem. We propose new search strategies for such heavy QCD axions at the Belle II experiment, where the axions are expected to be produced via $B\to K a$. We find that a subsequent decay $a\to 3\pi$ with a displaced vertex leads to a unique signal with essentially no background, and that a dedicated search can explore the range $O(1$-$10)$ TeV of decay-constant values. We also show that $a\to \gamma\gamma$ can cover a significant portion of currently unexplored region of $150 \lesssim m_a \lesssim 500$ MeV.
[ { "created": "Mon, 23 Aug 2021 18:00:05 GMT", "version": "v1" }, { "created": "Sun, 27 Mar 2022 19:15:53 GMT", "version": "v2" } ]
2022-04-27
[ [ "Bertholet", "Emilie", "" ], [ "Chakraborty", "Sabyasachi", "" ], [ "Loladze", "Vazha", "" ], [ "Okui", "Takemichi", "" ], [ "Soffer", "Abner", "" ], [ "Tobioka", "Kohsaku", "" ] ]
The QCD axion is a well-motivated addition to the standard model to solve the strong $C\!P$ problem. If the axion acquires mass dominantly from a hidden sector, it can be as heavy as $O(1)$ GeV, and the decay constant can be as low as $O(100)$ GeV without running into the axion quality problem. We propose new search strategies for such heavy QCD axions at the Belle II experiment, where the axions are expected to be produced via $B\to K a$. We find that a subsequent decay $a\to 3\pi$ with a displaced vertex leads to a unique signal with essentially no background, and that a dedicated search can explore the range $O(1$-$10)$ TeV of decay-constant values. We also show that $a\to \gamma\gamma$ can cover a significant portion of currently unexplored region of $150 \lesssim m_a \lesssim 500$ MeV.
2105.11102
Dmitry Gorbunov
Dmitry Gorbunov, Igor Krasnov, Sergey Suvorov
Constraints on light scalars from PS191 results
12 pages, 10 figures; v2: replaced with journal version
null
10.1016/j.physletb.2021.136524
INR-TH-2021-012
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We argue that the fixed target experiment PS191 operating on a proton beam of 19.2 GeV at CERN in the eighties was sensitive to hypothetical light scalars produced by mesons and decaying to charged particles. The experiment was dedicated to searches for sterile neutrinos produced in weak meson decays and decaying into final states with pairs of charged particles: electrons and muons. Two charged tracks from the same point have been adopted as the signal signature. Exploiting the same signature we use the negative results of searches at PS191 and place new limits on the light scalars coupled to the Standard Model (SM) particles via mixing with the Higgs boson. In particular, previously allowed region of masses 100--150 MeV and mixing above 4$\times 10^{-4}$ is disfavored. Our analysis can be extended straightforwardly to models with other patterns of scalar couplings to SM particles.
[ { "created": "Mon, 24 May 2021 05:47:12 GMT", "version": "v1" }, { "created": "Tue, 20 Jul 2021 18:44:12 GMT", "version": "v2" } ]
2021-07-28
[ [ "Gorbunov", "Dmitry", "" ], [ "Krasnov", "Igor", "" ], [ "Suvorov", "Sergey", "" ] ]
We argue that the fixed target experiment PS191 operating on a proton beam of 19.2 GeV at CERN in the eighties was sensitive to hypothetical light scalars produced by mesons and decaying to charged particles. The experiment was dedicated to searches for sterile neutrinos produced in weak meson decays and decaying into final states with pairs of charged particles: electrons and muons. Two charged tracks from the same point have been adopted as the signal signature. Exploiting the same signature we use the negative results of searches at PS191 and place new limits on the light scalars coupled to the Standard Model (SM) particles via mixing with the Higgs boson. In particular, previously allowed region of masses 100--150 MeV and mixing above 4$\times 10^{-4}$ is disfavored. Our analysis can be extended straightforwardly to models with other patterns of scalar couplings to SM particles.
1803.02292
Zhen-Xing Zhao
Zhen-Xing Zhao
Weak Decays of Heavy Baryons in Light-Front Approach
23 pages, 2 figures, to be published in Chinese Physics C
null
10.1088/1674-1137/42/9/093101
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we perform a analysis of semi-leptonic and nonleptonic weak decays of heavy baryons: $\Lambda_{b},\Xi_{b},\Omega_{b}$ and $\Lambda_{c},\Xi_{c},\Omega_{c}$. For nonleptonic decay modes, we study only the factorizable channels induced by the external W-emission. The two spectator quarks in baryonic transitions are treated as a diquark and form factors are calculated in the light-front approach. Using the results for form factors, we also calculate some corresponding semi-leptonic and nonleptonic decay widths. We find that our results are comparable with the available experimental data and other theoretical predictions. Decay branching fractions for many channels are found to reach the level $10^{-3}\sim10^{-2}$, which are promising to be discovered in the future measurements at BESIII, LHCb and BelleII. The SU(3) symmetry in semi-leptonic decays is examined and sources of symmetry breaking are discussed.
[ { "created": "Tue, 6 Mar 2018 16:46:58 GMT", "version": "v1" }, { "created": "Wed, 6 Jun 2018 05:13:54 GMT", "version": "v2" } ]
2018-09-26
[ [ "Zhao", "Zhen-Xing", "" ] ]
In this work, we perform a analysis of semi-leptonic and nonleptonic weak decays of heavy baryons: $\Lambda_{b},\Xi_{b},\Omega_{b}$ and $\Lambda_{c},\Xi_{c},\Omega_{c}$. For nonleptonic decay modes, we study only the factorizable channels induced by the external W-emission. The two spectator quarks in baryonic transitions are treated as a diquark and form factors are calculated in the light-front approach. Using the results for form factors, we also calculate some corresponding semi-leptonic and nonleptonic decay widths. We find that our results are comparable with the available experimental data and other theoretical predictions. Decay branching fractions for many channels are found to reach the level $10^{-3}\sim10^{-2}$, which are promising to be discovered in the future measurements at BESIII, LHCb and BelleII. The SU(3) symmetry in semi-leptonic decays is examined and sources of symmetry breaking are discussed.
1501.04942
Patrick Otto Ludl
Patrick Otto Ludl and Walter Grimus
A complete survey of texture zeros in general and symmetric quark mass matrices
11 pages, no figures
null
10.1016/j.physletb.2015.03.033
UWThPh-2015-2
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a systematic analysis of all possible texture zeros in general and symmetric quark mass matrices. Using the values of masses and mixing parameters at the electroweak scale, we identify for both cases the maximally restrictive viable textures. Furthermore, we investigate the predictive power of these textures by applying a numerical predictivity measure recently defined by us. With this measure we find no predictive textures among the viable general quark mass matrices, while in the case of symmetric quark mass matrices most of the 15 maximally restrictive textures are predictive with respect to one or more light quark masses.
[ { "created": "Tue, 20 Jan 2015 20:10:03 GMT", "version": "v1" } ]
2015-06-23
[ [ "Ludl", "Patrick Otto", "" ], [ "Grimus", "Walter", "" ] ]
We perform a systematic analysis of all possible texture zeros in general and symmetric quark mass matrices. Using the values of masses and mixing parameters at the electroweak scale, we identify for both cases the maximally restrictive viable textures. Furthermore, we investigate the predictive power of these textures by applying a numerical predictivity measure recently defined by us. With this measure we find no predictive textures among the viable general quark mass matrices, while in the case of symmetric quark mass matrices most of the 15 maximally restrictive textures are predictive with respect to one or more light quark masses.
1004.0749
Xin Liu
Xin Liu and Zhen-jun Xiao
$B \to K_0^*(1430) K$ decays in the perturbative QCD approach
7 pages, 2 figures
Commun. Theor. Phys.53:540, 2010
10.1088/0253-6102/53/3/26
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we calculate the branching ratios of $B \to K_0^*(1430) K$ decays by employing the perturbative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that (a) the leading order pQCD predictions for the branching ratio $Br(B^+ \to K^+ \bar{K_0^*}(1430)^0)$ which is in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered $B \to K_0^*(1430) K$ decay modes are also presented and will be tested by the LHC experiments; (b) the annihilation contributions play an important role in these considered decays, for $B^0 \to {K_0^*}(1430)^\pm {K}^\mp$ decays, for example, which are found to be $(1-4) \times 10^{-6}$.
[ { "created": "Tue, 6 Apr 2010 01:45:34 GMT", "version": "v1" } ]
2015-05-18
[ [ "Liu", "Xin", "" ], [ "Xiao", "Zhen-jun", "" ] ]
In this article, we calculate the branching ratios of $B \to K_0^*(1430) K$ decays by employing the perturbative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that (a) the leading order pQCD predictions for the branching ratio $Br(B^+ \to K^+ \bar{K_0^*}(1430)^0)$ which is in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered $B \to K_0^*(1430) K$ decay modes are also presented and will be tested by the LHC experiments; (b) the annihilation contributions play an important role in these considered decays, for $B^0 \to {K_0^*}(1430)^\pm {K}^\mp$ decays, for example, which are found to be $(1-4) \times 10^{-6}$.
1404.3642
Markus Huber Q.
Markus Q. Huber, Lorenz von Smekal
Spurious divergences in Dyson-Schwinger equations
19 pages, 9 figs; agrees with published version
JHEP06(2014)015
10.1007/JHEP06(2014)015
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the treatment of spurious ultraviolet divergences in the equation of motion of the gluon propagator caused by a momentum cutoff and the resulting violation of gauge invariance. With present continuum studies of the gluon propagator from its Dyson-Schwinger equation reaching the level of quantitatively accurate descriptions, it becomes increasingly important to understand how to subtract these spurious divergences in an unambiguous way. Here we propose such a method. It is based entirely on the asymptotic perturbative behavior of the QCD Green's functions without affecting non-perturbative aspects such as mass terms or the asymptotic infrared behavior. As a particular example, this allows us to assess the possible influence of the tadpole diagram beyond perturbation theory. Finally, we test this method numerically by solving the system of Dyson-Schwinger equations of the gluon and ghost propagators.
[ { "created": "Mon, 14 Apr 2014 16:15:58 GMT", "version": "v1" }, { "created": "Thu, 5 Jun 2014 08:55:47 GMT", "version": "v2" } ]
2015-06-19
[ [ "Huber", "Markus Q.", "" ], [ "von Smekal", "Lorenz", "" ] ]
We revisit the treatment of spurious ultraviolet divergences in the equation of motion of the gluon propagator caused by a momentum cutoff and the resulting violation of gauge invariance. With present continuum studies of the gluon propagator from its Dyson-Schwinger equation reaching the level of quantitatively accurate descriptions, it becomes increasingly important to understand how to subtract these spurious divergences in an unambiguous way. Here we propose such a method. It is based entirely on the asymptotic perturbative behavior of the QCD Green's functions without affecting non-perturbative aspects such as mass terms or the asymptotic infrared behavior. As a particular example, this allows us to assess the possible influence of the tadpole diagram beyond perturbation theory. Finally, we test this method numerically by solving the system of Dyson-Schwinger equations of the gluon and ghost propagators.
1706.07808
David Marzocca
Dario Buttazzo, Admir Greljo, Gino Isidori, David Marzocca
B-physics anomalies: a guide to combined explanations
33 pages, 7 figures, 2 tables. Extended discussion and one plot added on single production of leptoquarks, typos corrected, references added
null
10.1007/JHEP11(2017)044
ZU-TH-18/17
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by additional experimental hints of Lepton Flavour Universality violation in B decays, both in charged- and in neutral-current processes, we analyse the ingredients necessary to provide a combined description of these phenomena. By means of an Effective Field Theory (EFT) approach, based on the hypothesis of New Physics coupled predominantly to the third generation of left-handed quarks and leptons, we show how this is possible. We demonstrate, in particular, how to solve the problems posed by electroweak precision tests and direct searches with a rather natural choice of model parameters, within the context of a $U(2)_q \times U(2)_\ell$ flavour symmetry. We further exemplify the general EFT findings by means of simplified models with explicit mediators in the TeV range: coloured scalar or vector leptoquarks and colour-less vectors. Among these, the case of an $SU(2)_L$-singlet vector leptoquark emerges as a particularly simple and successful framework.
[ { "created": "Fri, 23 Jun 2017 18:00:02 GMT", "version": "v1" }, { "created": "Wed, 18 Oct 2017 15:05:19 GMT", "version": "v2" } ]
2017-12-06
[ [ "Buttazzo", "Dario", "" ], [ "Greljo", "Admir", "" ], [ "Isidori", "Gino", "" ], [ "Marzocca", "David", "" ] ]
Motivated by additional experimental hints of Lepton Flavour Universality violation in B decays, both in charged- and in neutral-current processes, we analyse the ingredients necessary to provide a combined description of these phenomena. By means of an Effective Field Theory (EFT) approach, based on the hypothesis of New Physics coupled predominantly to the third generation of left-handed quarks and leptons, we show how this is possible. We demonstrate, in particular, how to solve the problems posed by electroweak precision tests and direct searches with a rather natural choice of model parameters, within the context of a $U(2)_q \times U(2)_\ell$ flavour symmetry. We further exemplify the general EFT findings by means of simplified models with explicit mediators in the TeV range: coloured scalar or vector leptoquarks and colour-less vectors. Among these, the case of an $SU(2)_L$-singlet vector leptoquark emerges as a particularly simple and successful framework.
hep-ph/0411005
Steven D. Bass
Steven D. Bass
The Spin Structure of the Proton
47 pages. To appear in Reviews of Modern Physics
Rev.Mod.Phys.77:1257-1302,2005
10.1103/RevModPhys.77.1257
null
hep-ph
null
This article reviews our present understanding of the QCD spin structure of the proton. We first outline the proton spin puzzle and its possible resolution in QCD. We then review the present and next generation of experiments to resolve the proton's spin-flavour structure, explaining the theoretical issues involved, the present status of experimental investigation, and the open questions and challenges for future investigation.
[ { "created": "Sat, 30 Oct 2004 14:59:59 GMT", "version": "v1" }, { "created": "Fri, 10 Jun 2005 12:35:00 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bass", "Steven D.", "" ] ]
This article reviews our present understanding of the QCD spin structure of the proton. We first outline the proton spin puzzle and its possible resolution in QCD. We then review the present and next generation of experiments to resolve the proton's spin-flavour structure, explaining the theoretical issues involved, the present status of experimental investigation, and the open questions and challenges for future investigation.
1508.00576
Gabriel Lee
Gabriel Lee and Carlos E.M. Wagner
Higgs Bosons in Heavy Supersymmetry with an Intermediate $m_A$
44 pages, 13 figures. v2 has some additional text and references, updated figures, and corrections in the appendix. v3 is published version in PRD with minor copyediting corrections from v2
Phys. Rev. D 92, 075032 (2015)
10.1103/PhysRevD.92.075032
EFI Preprint 15-24
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The minimal supersymmetric standard model leads to precise predictions of the properties of the light Higgs boson degrees of freedom that depend on only a few relevant supersymmetry breaking parameters. In particular, there is an upper bound on the mass of the lightest neutral Higgs boson, which for a supersymmetric spectrum of the order of a TeV is barely above the one of the Higgs resonance recently observed at the LHC. This bound can be raised by considering a heavier supersymmetric spectrum, relaxing the tension between theory and experiment. In a previous article, we studied the predictions for the lightest CP-even Higgs mass for large values of the scalar-top and heavy Higgs boson masses. In this article we perform a similar analysis, considering also the case of a CP-odd Higgs boson mass $m_A$ of the order of the weak scale. We perform the calculation using effective theory techniques, considering a two-Higgs doublet model and a Standard Model-like theory and resumming the large logarithmic corrections that appear at scales above and below $m_A$, respectively. We calculate the mass and couplings of the lightest CP-even Higgs boson and compare our results with the ones obtained by other methods.
[ { "created": "Mon, 3 Aug 2015 20:11:54 GMT", "version": "v1" }, { "created": "Fri, 21 Aug 2015 19:53:07 GMT", "version": "v2" }, { "created": "Sun, 25 Oct 2015 15:25:37 GMT", "version": "v3" } ]
2015-10-28
[ [ "Lee", "Gabriel", "" ], [ "Wagner", "Carlos E. M.", "" ] ]
The minimal supersymmetric standard model leads to precise predictions of the properties of the light Higgs boson degrees of freedom that depend on only a few relevant supersymmetry breaking parameters. In particular, there is an upper bound on the mass of the lightest neutral Higgs boson, which for a supersymmetric spectrum of the order of a TeV is barely above the one of the Higgs resonance recently observed at the LHC. This bound can be raised by considering a heavier supersymmetric spectrum, relaxing the tension between theory and experiment. In a previous article, we studied the predictions for the lightest CP-even Higgs mass for large values of the scalar-top and heavy Higgs boson masses. In this article we perform a similar analysis, considering also the case of a CP-odd Higgs boson mass $m_A$ of the order of the weak scale. We perform the calculation using effective theory techniques, considering a two-Higgs doublet model and a Standard Model-like theory and resumming the large logarithmic corrections that appear at scales above and below $m_A$, respectively. We calculate the mass and couplings of the lightest CP-even Higgs boson and compare our results with the ones obtained by other methods.
2211.09023
Chengqun Pang
Ya-rong Wang, Yang Ma, Cheng-qun Pang
Can the three new states around 2.2 GeV assign to $\omega(3D)$
5 pages,2 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Recently, the BESIII Collaboration reported three resonances: $X(2232)$ with $M = 2232 \pm 19 \pm 27$ MeV and $\Gamma = 93 \pm 53 \pm 20$ MeV, $X(2200)$ whose mass $M = 2200 \pm 11 \pm 17$ MeV and width $\Gamma = 74 \pm 20 \pm 24$ MeV as well as $X(2222)$ which has mass of $2222 \pm 7 \pm 2$ MeV and the width of $59 \pm 30 \pm 6$ MeV. The mass spectrum of $\omega$ meson family is studied utilizing the modified Godfrey-Isgur model, and the two-body strong decays of $X(2232)$, $X(2200)$ and $X(2222)$ within two different approaches of the $^3P_0$ model. We find that the newly discovered states $X(2232)$, $X(2200)$ and $X(2222)$ may be the same and are most likely to be the $\omega(3D)$ state. The discovery could be useful in establishing entire $\omega$ mesons.
[ { "created": "Tue, 15 Nov 2022 16:12:50 GMT", "version": "v1" } ]
2022-11-17
[ [ "Wang", "Ya-rong", "" ], [ "Ma", "Yang", "" ], [ "Pang", "Cheng-qun", "" ] ]
Recently, the BESIII Collaboration reported three resonances: $X(2232)$ with $M = 2232 \pm 19 \pm 27$ MeV and $\Gamma = 93 \pm 53 \pm 20$ MeV, $X(2200)$ whose mass $M = 2200 \pm 11 \pm 17$ MeV and width $\Gamma = 74 \pm 20 \pm 24$ MeV as well as $X(2222)$ which has mass of $2222 \pm 7 \pm 2$ MeV and the width of $59 \pm 30 \pm 6$ MeV. The mass spectrum of $\omega$ meson family is studied utilizing the modified Godfrey-Isgur model, and the two-body strong decays of $X(2232)$, $X(2200)$ and $X(2222)$ within two different approaches of the $^3P_0$ model. We find that the newly discovered states $X(2232)$, $X(2200)$ and $X(2222)$ may be the same and are most likely to be the $\omega(3D)$ state. The discovery could be useful in establishing entire $\omega$ mesons.
1309.1979
Alexander Berezhnoy
A. V. Berezhnoy and A. K. Likhoded
The relative yields of heavy hadrons as function of transverse momentum at LHC experiments
15 pages, 10 figures, revtex4, $f_{B_c}/f_{B}$ has been estimated for the LHCb fiducial region
Phys.Atom.Nucl. 78 (2015) 2, 292-300
10.1134/S1063778815020106
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that the dependence of ratio $f_s/f_d$ could be understood within the fragmentation approach. However, the validity of fragmentation model is questionable at low $p_T$, and contributions of nonfragmentation mechanisms are possible. It is demonstrated, that the precise measurements of $p_T$ dependence of $f_s/f_d$, $f_{\Lambda_b}/f_{B}$ and analogous values as function of $p_T$ can essentially improve our understanding of heavy hadron production.At large $p_T$ a plateau is expected in $f_s/f_d$ distribution. Contrary, a plateau is not expected in $f_{B_c}/f_{B}$ distribution on $p_T$.
[ { "created": "Sun, 8 Sep 2013 17:04:23 GMT", "version": "v1" }, { "created": "Wed, 25 Sep 2013 13:18:07 GMT", "version": "v2" }, { "created": "Thu, 14 Nov 2013 09:43:44 GMT", "version": "v3" }, { "created": "Fri, 21 Mar 2014 08:58:00 GMT", "version": "v4" } ]
2022-02-10
[ [ "Berezhnoy", "A. V.", "" ], [ "Likhoded", "A. K.", "" ] ]
It is shown that the dependence of ratio $f_s/f_d$ could be understood within the fragmentation approach. However, the validity of fragmentation model is questionable at low $p_T$, and contributions of nonfragmentation mechanisms are possible. It is demonstrated, that the precise measurements of $p_T$ dependence of $f_s/f_d$, $f_{\Lambda_b}/f_{B}$ and analogous values as function of $p_T$ can essentially improve our understanding of heavy hadron production.At large $p_T$ a plateau is expected in $f_s/f_d$ distribution. Contrary, a plateau is not expected in $f_{B_c}/f_{B}$ distribution on $p_T$.
1606.05452
Kazem Azizi
K. Azizi, G. Bozkir
Decuplet baryons in a hot medium
12 Pages, 4 Figures and 3 Tables
null
10.1140/epjc/s10052-016-4370-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The thermal properties of the light decuplet baryons are investigated in the framework of the thermal QCD sum rules. In particular, the behavior of the mass and residue of the $\Delta$, $\Sigma^{*}$, $\Xi^{*}$ and $\Omega$ baryons with respect to temperature are analyzed taking into account the additional operators coming up in the Wilson expansion at finite temperature. It is found that the mass and residue of these particles remain overall unaffected up to $T\simeq150~MeV$ but, beyond this point, they start to diminish, considerably.
[ { "created": "Fri, 17 Jun 2016 08:50:16 GMT", "version": "v1" }, { "created": "Mon, 12 Sep 2016 18:26:40 GMT", "version": "v2" } ]
2016-10-12
[ [ "Azizi", "K.", "" ], [ "Bozkir", "G.", "" ] ]
The thermal properties of the light decuplet baryons are investigated in the framework of the thermal QCD sum rules. In particular, the behavior of the mass and residue of the $\Delta$, $\Sigma^{*}$, $\Xi^{*}$ and $\Omega$ baryons with respect to temperature are analyzed taking into account the additional operators coming up in the Wilson expansion at finite temperature. It is found that the mass and residue of these particles remain overall unaffected up to $T\simeq150~MeV$ but, beyond this point, they start to diminish, considerably.
1908.09843
Subhajit Ghosh
Subhajit Ghosh, Rishi Khatri, and Tuhin S. Roy
Dark Neutrino interactions phase out the Hubble tension
12 pages and 7 figures. Includes extended discussion and additional figures. Published version
Phys. Rev. D 102, 123544 (2020)
10.1103/PhysRevD.102.123544
TIFR/TH/19-31
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New interactions of neutrinos can stop them from free streaming even after the weak interaction freeze-out. This results in a phase shift in the cosmic microwave background (CMB) acoustic peaks which can alleviate the Hubble tension. In addition, the perturbations in neutrinos do not decay away on horizon entry and contribute to metric perturbation enhancing the matter power spectrum. We demonstrate that this acoustic phase shift can be achieved using new interactions of standard left-handed neutrinos with dark matter without changing the number of effective relativistic degrees of freedom. Using Planck CMB and the WiggleZ galaxy survey $ (k\le 0.12 h \ {\rm Mpc}^{-1} ) $ data, we demonstrate that in this model the Hubble tension reduces to approximately $ 2.1 \sigma$. Our model predicts potentially observable modifications of the CMB B-modes and the matter power spectrum that can be observed in future data sets.
[ { "created": "Mon, 26 Aug 2019 18:00:03 GMT", "version": "v1" }, { "created": "Sun, 10 Jan 2021 05:49:45 GMT", "version": "v2" } ]
2021-01-12
[ [ "Ghosh", "Subhajit", "" ], [ "Khatri", "Rishi", "" ], [ "Roy", "Tuhin S.", "" ] ]
New interactions of neutrinos can stop them from free streaming even after the weak interaction freeze-out. This results in a phase shift in the cosmic microwave background (CMB) acoustic peaks which can alleviate the Hubble tension. In addition, the perturbations in neutrinos do not decay away on horizon entry and contribute to metric perturbation enhancing the matter power spectrum. We demonstrate that this acoustic phase shift can be achieved using new interactions of standard left-handed neutrinos with dark matter without changing the number of effective relativistic degrees of freedom. Using Planck CMB and the WiggleZ galaxy survey $ (k\le 0.12 h \ {\rm Mpc}^{-1} ) $ data, we demonstrate that in this model the Hubble tension reduces to approximately $ 2.1 \sigma$. Our model predicts potentially observable modifications of the CMB B-modes and the matter power spectrum that can be observed in future data sets.
1312.2123
C. J. A. P. Martins
A. Ach\'ucarro, A. Avgoustidis, A. M. M. Leite, A. Lopez-Eiguren, C. J. A. P. Martins, A. S. Nunes and J. Urrestilla
Evolution of Semilocal String Networks: I. Large-scale Properties
13 pages, 4 figures; v2: minimal changes, matches version published in PRD
Phys.Rev. D89 (2014) 063503
10.1103/PhysRevD.89.063503
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on a detailed numerical study of the evolution of semilocal string networks, based on the largest and most accurate field theory simulations of these objects to date. We focus on the large-scale network properties, confirming earlier indications (coming from smaller simulations) that linear scaling is the attractor solution for the entire parameter space of initial conditions that we are able to probe. We also provide a brief comparison of our numerical results with the predictions of a previously developed one-scale model for the overall evolution of these networks. Two subsequent papers will discuss in more detail the analytic modeling of the semilocal segment populations as well as optimized numerical diagnostics.
[ { "created": "Sat, 7 Dec 2013 18:24:25 GMT", "version": "v1" }, { "created": "Mon, 10 Mar 2014 11:28:02 GMT", "version": "v2" } ]
2014-03-24
[ [ "Achúcarro", "A.", "" ], [ "Avgoustidis", "A.", "" ], [ "Leite", "A. M. M.", "" ], [ "Lopez-Eiguren", "A.", "" ], [ "Martins", "C. J. A. P.", "" ], [ "Nunes", "A. S.", "" ], [ "Urrestilla", "J.", "" ] ]
We report on a detailed numerical study of the evolution of semilocal string networks, based on the largest and most accurate field theory simulations of these objects to date. We focus on the large-scale network properties, confirming earlier indications (coming from smaller simulations) that linear scaling is the attractor solution for the entire parameter space of initial conditions that we are able to probe. We also provide a brief comparison of our numerical results with the predictions of a previously developed one-scale model for the overall evolution of these networks. Two subsequent papers will discuss in more detail the analytic modeling of the semilocal segment populations as well as optimized numerical diagnostics.
0812.4728
Lei Guo
Dong Chuan-Fei, Ma Wen-Gan, Zhang Ren-You, Guo Lei and Wang Shao-Ming
SUSY QCD impact on top-pair production associated with a $Z^0$-boson at a photon-photon collider
22 pages and 13 figures
Commun.Theor.Phys.52:302-310,2009
10.1088/0253-6102/52/2/23
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The top-pair production in association with a $Z^0$-boson at a photon-photon collider is an important process in probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics. We describe the impact of the complete supersymmetric QCD(SQCD) next-to-leading order(NLO) radiative corrections on this process at a polarized or unpolarized photon collider, and make a comparison between the effects of the SQCD and the standard model(SM) QCD. We investigate the dependence of the lowest-order(LO) and QCD NLO corrected cross sections in both the SM and minimal supersymmetric standard model(MSSM) on colliding energy $\sqrt{s}$ in different polarized photon collision modes. The LO, SM NLO and SQCD NLO corrected distributions of the invariant mass of $t\bar t$-pair and the transverse momenta of final $Z^0$-boson are presented. Our numerical results show that the pure SQCD effects in \ggttz process can be more significant in the $+ +$ polarized photon collision mode than in other collision modes, and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to $-1.89 %$ when $\sqrt{s}$ goes up from $500 GeV$ to $1.5 TeV$.
[ { "created": "Sat, 27 Dec 2008 10:08:32 GMT", "version": "v1" } ]
2009-08-11
[ [ "Chuan-Fei", "Dong", "" ], [ "Wen-Gan", "Ma", "" ], [ "Ren-You", "Zhang", "" ], [ "Lei", "Guo", "" ], [ "Shao-Ming", "Wang", "" ] ]
The top-pair production in association with a $Z^0$-boson at a photon-photon collider is an important process in probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics. We describe the impact of the complete supersymmetric QCD(SQCD) next-to-leading order(NLO) radiative corrections on this process at a polarized or unpolarized photon collider, and make a comparison between the effects of the SQCD and the standard model(SM) QCD. We investigate the dependence of the lowest-order(LO) and QCD NLO corrected cross sections in both the SM and minimal supersymmetric standard model(MSSM) on colliding energy $\sqrt{s}$ in different polarized photon collision modes. The LO, SM NLO and SQCD NLO corrected distributions of the invariant mass of $t\bar t$-pair and the transverse momenta of final $Z^0$-boson are presented. Our numerical results show that the pure SQCD effects in \ggttz process can be more significant in the $+ +$ polarized photon collision mode than in other collision modes, and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to $-1.89 %$ when $\sqrt{s}$ goes up from $500 GeV$ to $1.5 TeV$.
hep-ph/0610071
Ignacio General
Stephen R. Cotanch, Ignacio J. General and Ping Wang
QCD Coulomb Gauge Approach to Exotic Hadrons
6 pages, 9 figures
Eur.Phys.J.A31:656-661,2007
10.1140/epja/i2006-10234-2
null
hep-ph
null
The Coulomb gauge Hamiltonian model is used to calculate masses for selected J^{PC} states consisting of exotic combinations of quarks and gluons: ggg glueballs (oddballs), q bar{q} g hybrid mesons and q bar{q} q bar{q} tetraquark systems. An odderon Regge trajectory is computed for the J^{--} glueballs with intercept much smaller than the pomeron, explaining its nonobservation. The lowest 1^{-+} hybrid meson mass is found to be just above 2.2 GeV while the lightest tetraquark state mass with these exotic quantum numbers is predicted around 1.4 GeV consistent with the observed pi(1400).
[ { "created": "Fri, 6 Oct 2006 04:39:56 GMT", "version": "v1" } ]
2008-11-26
[ [ "Cotanch", "Stephen R.", "" ], [ "General", "Ignacio J.", "" ], [ "Wang", "Ping", "" ] ]
The Coulomb gauge Hamiltonian model is used to calculate masses for selected J^{PC} states consisting of exotic combinations of quarks and gluons: ggg glueballs (oddballs), q bar{q} g hybrid mesons and q bar{q} q bar{q} tetraquark systems. An odderon Regge trajectory is computed for the J^{--} glueballs with intercept much smaller than the pomeron, explaining its nonobservation. The lowest 1^{-+} hybrid meson mass is found to be just above 2.2 GeV while the lightest tetraquark state mass with these exotic quantum numbers is predicted around 1.4 GeV consistent with the observed pi(1400).
1710.07860
Sebasti\'an Felipe Mantilla Serrano
S. F. Mantilla and R. Martinez
A new U(1) model anomaly free for three families to address fermion mass hierarchy and neutrino physics
Conference proceedings from XI Latin American Symposium of High Energy Physics (SILAFAE 2016) from November 14th to 18th of 2016 in Antigua Guatemala, Guatemala
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new non-universal abelian extension $\mathrm{G_{SM}}\otimes \mathrm{U(1)}_{X}$ to the Standard Model free from chiral anomalies is presented. The new $X$ charges distinguish among generations so as the fermion mass matrices get zero-textures from the fermion mass hierarchy can be obtained. Regarding to neutrino physics, the model inclues Majorana fermions which induce see-saw mechanisms to get small neutrino masses. Moreover, the suitability of the model is tested by searching for regions in the parameter space which reproduce current neutrino oscillation data.
[ { "created": "Sat, 21 Oct 2017 22:59:01 GMT", "version": "v1" } ]
2017-10-24
[ [ "Mantilla", "S. F.", "" ], [ "Martinez", "R.", "" ] ]
A new non-universal abelian extension $\mathrm{G_{SM}}\otimes \mathrm{U(1)}_{X}$ to the Standard Model free from chiral anomalies is presented. The new $X$ charges distinguish among generations so as the fermion mass matrices get zero-textures from the fermion mass hierarchy can be obtained. Regarding to neutrino physics, the model inclues Majorana fermions which induce see-saw mechanisms to get small neutrino masses. Moreover, the suitability of the model is tested by searching for regions in the parameter space which reproduce current neutrino oscillation data.
hep-ph/9804369
null
Aiichi Iwazaki
Radiations from Oscillating Axionic Boson Stars in an External Magnetic Field
9 Pages Revtex
Phys.Lett. B451 (1999) 123-128
10.1016/S0370-2693(99)00209-9
Nisho-98/2
hep-ph
null
We solve numerically a field equation of axions coupled with gravity and show solutions representing oscillating axionic boson stars with small mass $\sim 10^{-12}M_{\odot}$ and large radius $\sim 10^{8}$ cm. We present explicitly a relation between the mass and the radius of the boson stars with such a small mass. These axionic boson stars are shown to possess oscillating electric currents in an external magnetic field and to radiate electromagnetic fields with a frequency given by mass of the axions. We estimate the luminosity of the radiation in a strong magnetic field $10^{12}$G of neutron stars, typically $\sim 10^{24}$ erg/s with the axion mass being $10^{-5}$eV.
[ { "created": "Thu, 23 Apr 1998 07:05:07 GMT", "version": "v1" } ]
2009-10-31
[ [ "Iwazaki", "Aiichi", "" ] ]
We solve numerically a field equation of axions coupled with gravity and show solutions representing oscillating axionic boson stars with small mass $\sim 10^{-12}M_{\odot}$ and large radius $\sim 10^{8}$ cm. We present explicitly a relation between the mass and the radius of the boson stars with such a small mass. These axionic boson stars are shown to possess oscillating electric currents in an external magnetic field and to radiate electromagnetic fields with a frequency given by mass of the axions. We estimate the luminosity of the radiation in a strong magnetic field $10^{12}$G of neutron stars, typically $\sim 10^{24}$ erg/s with the axion mass being $10^{-5}$eV.
1907.13151
Maria Ramos
Andrew Blance, Mikael Chala, Maria Ramos and Michael Spannowsky
Novel $B$-decay signatures of light scalars at high energy facilities
11 pages, 14 figures
Phys. Rev. D 100, 115015 (2019)
10.1103/PhysRevD.100.115015
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We study the phenomenology of light scalars of masses $m_1$ and $m_2$ coupling to heavy flavour-violating vector bosons of mass $m_V$. For $m_{1,2}\lesssim $ few GeV, this scenario triggers the rare $B$ meson decays $B_s^0\to 3\mu^+ 3\mu^-$, $B^0\to 3\mu^+ 3\mu^-$, $B^+\to K^+ 3\mu^+ 3\mu^-$ and $B_s^0\to K^{0*} 3\mu^+ 3\mu^-$; the last two being the most important ones for $m_1\sim m_2$. None of these signals has been studied experimentally; therefore we propose analyses to test these channels at the LHCb. We demonstrate that the reach of this facility extends to branching ratios as small as $6.0\times 10^{-9}$, $1.6\times 10^{-9}$, $5.9\times 10^{-9}$ and $1.8\times 10^{-8}$ for the aforementioned channels, respectively. For $m_{1,2}\gg \mathcal{O}(1)$ GeV, we show that slightly modified versions of current multilepton and multitau searches at the LHC can probe wide regions of the parameter space of this scenario. Altogether, the potential of the searches we propose outperform other constraints such as those from meson mixing.
[ { "created": "Tue, 30 Jul 2019 18:01:21 GMT", "version": "v1" } ]
2019-12-11
[ [ "Blance", "Andrew", "" ], [ "Chala", "Mikael", "" ], [ "Ramos", "Maria", "" ], [ "Spannowsky", "Michael", "" ] ]
We study the phenomenology of light scalars of masses $m_1$ and $m_2$ coupling to heavy flavour-violating vector bosons of mass $m_V$. For $m_{1,2}\lesssim $ few GeV, this scenario triggers the rare $B$ meson decays $B_s^0\to 3\mu^+ 3\mu^-$, $B^0\to 3\mu^+ 3\mu^-$, $B^+\to K^+ 3\mu^+ 3\mu^-$ and $B_s^0\to K^{0*} 3\mu^+ 3\mu^-$; the last two being the most important ones for $m_1\sim m_2$. None of these signals has been studied experimentally; therefore we propose analyses to test these channels at the LHCb. We demonstrate that the reach of this facility extends to branching ratios as small as $6.0\times 10^{-9}$, $1.6\times 10^{-9}$, $5.9\times 10^{-9}$ and $1.8\times 10^{-8}$ for the aforementioned channels, respectively. For $m_{1,2}\gg \mathcal{O}(1)$ GeV, we show that slightly modified versions of current multilepton and multitau searches at the LHC can probe wide regions of the parameter space of this scenario. Altogether, the potential of the searches we propose outperform other constraints such as those from meson mixing.
0912.4171
Takayuki Matsuki
T. Matsuki, X. Liu, T. Morii, and K. Seo
Derivation of a 1/r^2 potential term for QQ-bar in a potential model
3 pages, QNP09 conference
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We clarify the difference among potential models so far proposed to explain mass spectra of heavy-light mesons via transformations of the vacuum. Applying our idea to QQ-bar quarkonium, we obtain the extra term, 1/r^2 with positive coefficient, other than non-relativistic potential terms expected for quarkonium.
[ { "created": "Mon, 21 Dec 2009 14:15:29 GMT", "version": "v1" } ]
2009-12-25
[ [ "Matsuki", "T.", "" ], [ "Liu", "X.", "" ], [ "Morii", "T.", "" ], [ "Seo", "K.", "" ] ]
We clarify the difference among potential models so far proposed to explain mass spectra of heavy-light mesons via transformations of the vacuum. Applying our idea to QQ-bar quarkonium, we obtain the extra term, 1/r^2 with positive coefficient, other than non-relativistic potential terms expected for quarkonium.
0910.1972
Jitesh Bhatt
Jitesh R. Bhatt and V. Sreekanth
Boson stars: Chemical potential and quark condensates
(8 pages, 7 figures) Extensively modified the introduction and new references added.
null
null
null
hep-ph astro-ph.HE astro-ph.SR gr-qc nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the properties of a star made of self-gravitating bosons gas in a mean-field approximation. A generalized set of Tolman-Oppenheimer-Volkov(TOV) equations is derived to incorporate the effect of chemical-potential in the general relativistic frame work. The metric-dependence of the chemical-potential gives a new class of solutions for the boson stars. It is demonstrated that the maximum mass and radius of the star change in a significant way when the effect of finite chemical-potential is considered. We also discuss the case of a boson star made of quark-condensates. It is found that when the self-interaction between the condensates is small as compared to their mass, the typical density is too high to form a diquark-boson star. Our results indicate that the star of quark-condensate may be formed in a low-density and high-pressure regime.
[ { "created": "Mon, 12 Oct 2009 11:48:26 GMT", "version": "v1" }, { "created": "Thu, 6 May 2010 16:41:49 GMT", "version": "v2" } ]
2010-05-07
[ [ "Bhatt", "Jitesh R.", "" ], [ "Sreekanth", "V.", "" ] ]
We study the properties of a star made of self-gravitating bosons gas in a mean-field approximation. A generalized set of Tolman-Oppenheimer-Volkov(TOV) equations is derived to incorporate the effect of chemical-potential in the general relativistic frame work. The metric-dependence of the chemical-potential gives a new class of solutions for the boson stars. It is demonstrated that the maximum mass and radius of the star change in a significant way when the effect of finite chemical-potential is considered. We also discuss the case of a boson star made of quark-condensates. It is found that when the self-interaction between the condensates is small as compared to their mass, the typical density is too high to form a diquark-boson star. Our results indicate that the star of quark-condensate may be formed in a low-density and high-pressure regime.
hep-ph/9309274
Sanghyeon Chang
Sanghyeon Chang and Jihn E. Kim
Fermion Doubling and a Natural Solution of the Strong CP Problem
SNUTP 93-68, 19 pages 1 TeX figure, ReVTeX 3.0
Phys.Rev.D50:2218-2224,1994
10.1103/PhysRevD.50.2218
null
hep-ph
null
We suggest the fermion doubling for all quarks and leptons. It is a generalization of the neutrino doubling of the seesaw mechanism. The new quarks and leptons are $SU(2)$ singlets and carry the electromagnetic charges of their lighter counterparts. An $SU(3)$ {\it anomaly free global symmetry} or a discrete symmetry can be introduced to restrict the Yukawa couplings. The form of mass matrix is belonging to that of Nelson and Barr even though our model does not belong to Barr's criterion. The weak CP violation of the Kobayashi-Maskawa form is obtained through the spontaneous breaking of CP symmetry at high energy scale. The strong CP solution is through a specific form of the mass matrix. At low energy, the particle content is the same as in the standard model. For a model with a global symmetry, in addition there exists a massless majoron.
[ { "created": "Thu, 16 Sep 1993 03:06:43 GMT", "version": "v1" }, { "created": "Fri, 8 Apr 1994 02:53:40 GMT", "version": "v2" } ]
2010-11-01
[ [ "Chang", "Sanghyeon", "" ], [ "Kim", "Jihn E.", "" ] ]
We suggest the fermion doubling for all quarks and leptons. It is a generalization of the neutrino doubling of the seesaw mechanism. The new quarks and leptons are $SU(2)$ singlets and carry the electromagnetic charges of their lighter counterparts. An $SU(3)$ {\it anomaly free global symmetry} or a discrete symmetry can be introduced to restrict the Yukawa couplings. The form of mass matrix is belonging to that of Nelson and Barr even though our model does not belong to Barr's criterion. The weak CP violation of the Kobayashi-Maskawa form is obtained through the spontaneous breaking of CP symmetry at high energy scale. The strong CP solution is through a specific form of the mass matrix. At low energy, the particle content is the same as in the standard model. For a model with a global symmetry, in addition there exists a massless majoron.
1101.2539
Felipe J. Llanes-Estrada
Felipe J. Llanes-Estrada, Jose Ramon Pelaez and Jacobo Ruiz de Elvira (Univ. Complutense Madrid)
Fock space expansion of sigma meson in leading-Nc
4 pages, 4 figures, Proceedings of QCD10, the 15th High-Energy Physics International Conference on Quantum Chromodynamics
Nuclear Physics B (Proc. Suppl.) 207-208 (2010) 169-172
10.1016/j.nuclphysbps.2010.10.044
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the leading-Nc behavior of the masses and transition matrix elements of some low-lying, few-particle configurations in QCD. A truncation of the Fock space produces an effective, symmetric Hamiltonian that we diagonalize. The lowest eigenvalue is identified as the sigma meson if the Hamiltonian is chosen to represent the scalar sector. As an application, the coefficients of the Nc powers are then fit to two-loop Unitarized SU(2) Chiral Perturbation Theory results for the sigma mass and width as a function of the number of colors, and we show that those results can be accommodated using the QCD Nc dependence previously derived for matrix elements, without the need for unnatural parameters or fine tunings. Finally, we show a very preliminary good quality fit, estimating the proportion of tetraquark/molecule-like (dominant), q-anti-q-like (subdominant) and exotic-like (marginal) configurations in the sigma.
[ { "created": "Thu, 13 Jan 2011 11:33:04 GMT", "version": "v1" } ]
2015-03-17
[ [ "Llanes-Estrada", "Felipe J.", "", "Univ. Complutense Madrid" ], [ "Pelaez", "Jose Ramon", "", "Univ. Complutense Madrid" ], [ "de Elvira", "Jacobo Ruiz", "", "Univ. Complutense Madrid" ] ]
We examine the leading-Nc behavior of the masses and transition matrix elements of some low-lying, few-particle configurations in QCD. A truncation of the Fock space produces an effective, symmetric Hamiltonian that we diagonalize. The lowest eigenvalue is identified as the sigma meson if the Hamiltonian is chosen to represent the scalar sector. As an application, the coefficients of the Nc powers are then fit to two-loop Unitarized SU(2) Chiral Perturbation Theory results for the sigma mass and width as a function of the number of colors, and we show that those results can be accommodated using the QCD Nc dependence previously derived for matrix elements, without the need for unnatural parameters or fine tunings. Finally, we show a very preliminary good quality fit, estimating the proportion of tetraquark/molecule-like (dominant), q-anti-q-like (subdominant) and exotic-like (marginal) configurations in the sigma.
2208.07882
Kevin Langhoff
Csaba Cs\'aki, Andrew Gomes, Yonit Hochberg, Eric Kuflik, Kevin Langhoff, Hitoshi Murayama
Super-Resonant Dark Matter
null
null
10.1007/JHEP11(2022)162
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We introduce Super-Resonant Dark Matter, a model of self-interacting dark matter based on the low energy effective theory of supersymmetric QCD. The structure of the theory ensures a resonant enhancement of the self-interactions of the low energy mesons, since their mass ratio is set by the number of colors and flavors. The velocity dependence of the resonantly enhanced self-interactions allows such theories to accommodate puzzles in small scale structure that arise from dark matter halos of different sizes. The dark matter mass is then predicted to be around 3-4 MeV, with its abundance set by freeze-in via a kinetically mixed dark photon.
[ { "created": "Tue, 16 Aug 2022 18:00:01 GMT", "version": "v1" } ]
2022-12-14
[ [ "Csáki", "Csaba", "" ], [ "Gomes", "Andrew", "" ], [ "Hochberg", "Yonit", "" ], [ "Kuflik", "Eric", "" ], [ "Langhoff", "Kevin", "" ], [ "Murayama", "Hitoshi", "" ] ]
We introduce Super-Resonant Dark Matter, a model of self-interacting dark matter based on the low energy effective theory of supersymmetric QCD. The structure of the theory ensures a resonant enhancement of the self-interactions of the low energy mesons, since their mass ratio is set by the number of colors and flavors. The velocity dependence of the resonantly enhanced self-interactions allows such theories to accommodate puzzles in small scale structure that arise from dark matter halos of different sizes. The dark matter mass is then predicted to be around 3-4 MeV, with its abundance set by freeze-in via a kinetically mixed dark photon.
hep-ph/0108087
Jose Antonio Martins Simoes
J.A. Martins Simoes, Y.A. Coutinho and C.M. Porto
Spontaneous parity breaking and fermion masses
3 pages; to appear in the proceedings of the International Europhysics Conference on High Energy Physics, July 12-18 2001, Budapest
null
null
null
hep-ph
null
We present a SU(2)_L * SU(2)_R * U(1) left-right symmetric model for elementary particles and their connection with the fermion mass spectrum. New mirror fermions and a minimal set of Higgs particles are proposed. The model can accommodate a consistent pattern for charged and neutral fermion masses as well as neutrino oscillations. The connection between the left and right sectors can be done by the neutral vector gauge boson Z and a new heavy Z'.
[ { "created": "Thu, 9 Aug 2001 16:55:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Simoes", "J. A. Martins", "" ], [ "Coutinho", "Y. A.", "" ], [ "Porto", "C. M.", "" ] ]
We present a SU(2)_L * SU(2)_R * U(1) left-right symmetric model for elementary particles and their connection with the fermion mass spectrum. New mirror fermions and a minimal set of Higgs particles are proposed. The model can accommodate a consistent pattern for charged and neutral fermion masses as well as neutrino oscillations. The connection between the left and right sectors can be done by the neutral vector gauge boson Z and a new heavy Z'.
hep-ph/0404011
Kanzo Nakayama
K. Nakayama and W. G. Love
Spin observables and the determination of the parity of $\Theta^+$ in photoproduction reactions
LaTeX, 11 pages, minor revision
Phys.Rev. C70 (2004) 012201
10.1103/PhysRevC.70.012201
null
hep-ph
null
Spin observables in the photoproduction of the $\Theta^+$ are explored for the purpose of determining the parity of the $\Theta^+$. Based on reflection symmetry in the scattering plane, we show that certain spin observables in the photoproduction of the $\Theta^+$ can be related directly to its parity. We also show that measurements of both the target nucleon asymmetry and the $% \Theta^+$ polarization may be useful in determining the parity of $\Theta^+$ in a model-independent way. Furthermore, we show that no combination of spin observables involving only the polarization of the photon and/or nucleon in the initial state can determine the parity of $\Theta^+$ unambiguously.
[ { "created": "Thu, 1 Apr 2004 18:59:23 GMT", "version": "v1" }, { "created": "Fri, 2 Apr 2004 20:28:09 GMT", "version": "v2" }, { "created": "Wed, 28 Jul 2004 16:00:07 GMT", "version": "v3" } ]
2009-11-10
[ [ "Nakayama", "K.", "" ], [ "Love", "W. G.", "" ] ]
Spin observables in the photoproduction of the $\Theta^+$ are explored for the purpose of determining the parity of the $\Theta^+$. Based on reflection symmetry in the scattering plane, we show that certain spin observables in the photoproduction of the $\Theta^+$ can be related directly to its parity. We also show that measurements of both the target nucleon asymmetry and the $% \Theta^+$ polarization may be useful in determining the parity of $\Theta^+$ in a model-independent way. Furthermore, we show that no combination of spin observables involving only the polarization of the photon and/or nucleon in the initial state can determine the parity of $\Theta^+$ unambiguously.
0709.3266
Vladimir Gudkov
V. Gudkov, H. M. Shimizu and G. L. Greene
Parametric Resonance Enhancement in Neutron Interferometry and Search for Non-Newtonian Gravity
null
Phys.Rev.C83:025501,2011
10.1103/PhysRevC.83.025501
null
hep-ph
null
The parametric resonance enhancement of the phase of neutrons due to non-Newtonian anomalous gravitational is considered. The existence of such resonances are confirmed by numerical calculations. A possible experimental scheme for the observation of this effect is discussed based on an existing neutron interferometer design.
[ { "created": "Thu, 20 Sep 2007 17:11:50 GMT", "version": "v1" } ]
2011-03-02
[ [ "Gudkov", "V.", "" ], [ "Shimizu", "H. M.", "" ], [ "Greene", "G. L.", "" ] ]
The parametric resonance enhancement of the phase of neutrons due to non-Newtonian anomalous gravitational is considered. The existence of such resonances are confirmed by numerical calculations. A possible experimental scheme for the observation of this effect is discussed based on an existing neutron interferometer design.
hep-ph/9812303
Felice Pisano
A. Doff and F. Pisano
Charge quantization in the largest leptoquark-bilepton chiral electroweak scheme
13 pages
Mod.Phys.Lett.A14:1133-1142,1999
10.1142/S0217732399001218
null
hep-ph
null
The uniqueness of the hypercharge assignments in the three fermion families leptoquark-bilepton $SU(3)_C \times SU(4)_L \times U(1)_N$ model is established. Although the gauge group contains an explicit U(1) factor, freedom from triangle anomalies combined with the requirement of nonvanishing charged fermion masses uniquely fix the electric charges of all fermions independently of the neutrinos being massless or not. The electric-charge quantization, family replication, and the existence of three colors are interwoven.
[ { "created": "Wed, 9 Dec 1998 18:13:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "Doff", "A.", "" ], [ "Pisano", "F.", "" ] ]
The uniqueness of the hypercharge assignments in the three fermion families leptoquark-bilepton $SU(3)_C \times SU(4)_L \times U(1)_N$ model is established. Although the gauge group contains an explicit U(1) factor, freedom from triangle anomalies combined with the requirement of nonvanishing charged fermion masses uniquely fix the electric charges of all fermions independently of the neutrinos being massless or not. The electric-charge quantization, family replication, and the existence of three colors are interwoven.
hep-ph/0401062
Ivan Vitev
Jianwei Qiu, Ivan Vitev
Nuclear shadowing in neutrino-nucleus deeply inelastic scattering
7 pages, 4 figures, RevTeX 4
Phys.Lett. B587 (2004) 52-61
10.1016/j.physletb.2004.02.065
null
hep-ph
null
In the framework of the collinear factorized pQCD approach we calculate the small-$x_B$ process-dependent nuclear modification to the structure functions measured in neutrino-nucleus deeply inelastic scattering. We include both heavy quark mass corrections $(M^2/Q^2)$ and resummed nuclear-enhanced dynamical power corrections in the quantity $(\xi^2/Q^2)(A^{1/3}-1)$ with $\xi^2$ evaluated to leading order in $\alpha_s$. Our formalism predicts a measurable difference in the shadowing pattern of the structure functions $F_2^A(x_B,Q^2)$ and $F_3^A(x_B,Q^2)$ and a significant low- and moderate-$Q^2$ modification of the QCD sum rules. We also comment on the relevance of our results to the NuTeV extraction of $\sin^2\theta_W$.
[ { "created": "Sat, 10 Jan 2004 14:22:36 GMT", "version": "v1" } ]
2009-11-10
[ [ "Qiu", "Jianwei", "" ], [ "Vitev", "Ivan", "" ] ]
In the framework of the collinear factorized pQCD approach we calculate the small-$x_B$ process-dependent nuclear modification to the structure functions measured in neutrino-nucleus deeply inelastic scattering. We include both heavy quark mass corrections $(M^2/Q^2)$ and resummed nuclear-enhanced dynamical power corrections in the quantity $(\xi^2/Q^2)(A^{1/3}-1)$ with $\xi^2$ evaluated to leading order in $\alpha_s$. Our formalism predicts a measurable difference in the shadowing pattern of the structure functions $F_2^A(x_B,Q^2)$ and $F_3^A(x_B,Q^2)$ and a significant low- and moderate-$Q^2$ modification of the QCD sum rules. We also comment on the relevance of our results to the NuTeV extraction of $\sin^2\theta_W$.
hep-ph/0211456
Harald Anlauf
Harald Anlauf
QED Radiative Processes in Deep Inelastic Scattering at HERA
137 pages, 25 figures. Habilitation thesis
null
null
null
hep-ph
null
High energy scattering processes of charged particles are accompanied by radiation of hard photons. Emission collinear to the incident particles, which leads to a reduction of the effective beam energy, and the possibility to directly measure these photons at the HERA electron-proton collider provides important physics opportunities. For deep inelastic scattering, the measurement of radiative processes extends the kinematic range accessible to the HERA experiments to lower Q^2, as well as helps in separating the proton structure functions without the need to run at different collider energies. QED corrections to these radiative processes are discussed, and the calculation of the model-independent leptonic corrections is described in some detail for the complete one-loop contributions as well as for the higher order leading logarithms.
[ { "created": "Fri, 29 Nov 2002 11:39:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Anlauf", "Harald", "" ] ]
High energy scattering processes of charged particles are accompanied by radiation of hard photons. Emission collinear to the incident particles, which leads to a reduction of the effective beam energy, and the possibility to directly measure these photons at the HERA electron-proton collider provides important physics opportunities. For deep inelastic scattering, the measurement of radiative processes extends the kinematic range accessible to the HERA experiments to lower Q^2, as well as helps in separating the proton structure functions without the need to run at different collider energies. QED corrections to these radiative processes are discussed, and the calculation of the model-independent leptonic corrections is described in some detail for the complete one-loop contributions as well as for the higher order leading logarithms.
2008.12773
Matthias Schlaffer
Elina Fuchs, Oleksii Matsedonskyi, Inbar Savoray, Matthias Schlaffer
Collider searches of scalar singlets across lifetimes
24 pages + appendices and references, 10 figures
null
10.1007/JHEP04(2021)019
FERMILAB-PUB-20-454-T, EFI-20-17
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spin-0 singlets arise in well-motivated extensions of the Standard Model. Their lifetime determines the best search strategies at hadron and lepton colliders. To cover a large range of singlet decay lengths, we investigate bounds from Higgs decays into a pair of singlets, considering signatures of invisible decays, displaced and delayed jets, and coupling fits of untagged decays. We examine the generic scalar singlet and the relaxion, and derive a matching as well as qualitative differences between them. For each model, we discuss its natural parameter space and the searches probing it.
[ { "created": "Fri, 28 Aug 2020 17:52:14 GMT", "version": "v1" } ]
2021-04-21
[ [ "Fuchs", "Elina", "" ], [ "Matsedonskyi", "Oleksii", "" ], [ "Savoray", "Inbar", "" ], [ "Schlaffer", "Matthias", "" ] ]
Spin-0 singlets arise in well-motivated extensions of the Standard Model. Their lifetime determines the best search strategies at hadron and lepton colliders. To cover a large range of singlet decay lengths, we investigate bounds from Higgs decays into a pair of singlets, considering signatures of invisible decays, displaced and delayed jets, and coupling fits of untagged decays. We examine the generic scalar singlet and the relaxion, and derive a matching as well as qualitative differences between them. For each model, we discuss its natural parameter space and the searches probing it.
hep-ph/0208186
Horace W. Crater
Horace Crater, Peter Van Alstine
Relativistic Calculation of the Meson Spectrum: a Fully Covariant Treatment Versus Standard Treatments
75 pages, 6 figures, revised contents
Phys.Rev. D70 (2004) 034026
10.1103/PhysRevD.70.034026
null
hep-ph nucl-th
null
A large number of treatments of the meson spectrum have been tried that consider mesons as quark - anti quark bound states. Recently, we used relativistic quantum "constraint" mechanics to introduce a fully covariant treatment defined by two coupled Dirac equations. For field-theoretic interactions, this procedure functions as a "quantum mechanical transform of Bethe-Salpeter equation". Here, we test its spectral fits against those provided by an assortment of models: Wisconsin model, Iowa State model, Brayshaw model, and the popular semi-relativistic treatment of Godfrey and Isgur. We find that the fit provided by the two-body Dirac model for the entire meson spectrum competes with the best fits to partial spectra provided by the others and does so with the smallest number of interaction functions without additional cutoff parameters necessary to make other approaches numerically tractable. We discuss the distinguishing features of our model that may account for the relative overall success of its fits. Note especially that in our approach for QCD, the resulting pion mass and associated Goldstone behavior depend sensitively on the preservation of relativistic couplings that are crucial for its success when solved nonperturbatively for the analogous two-body bound-states of QED.
[ { "created": "Tue, 20 Aug 2002 20:49:02 GMT", "version": "v1" }, { "created": "Wed, 20 Nov 2002 01:42:46 GMT", "version": "v2" }, { "created": "Sat, 24 Apr 2004 17:09:28 GMT", "version": "v3" } ]
2009-11-07
[ [ "Crater", "Horace", "" ], [ "Van Alstine", "Peter", "" ] ]
A large number of treatments of the meson spectrum have been tried that consider mesons as quark - anti quark bound states. Recently, we used relativistic quantum "constraint" mechanics to introduce a fully covariant treatment defined by two coupled Dirac equations. For field-theoretic interactions, this procedure functions as a "quantum mechanical transform of Bethe-Salpeter equation". Here, we test its spectral fits against those provided by an assortment of models: Wisconsin model, Iowa State model, Brayshaw model, and the popular semi-relativistic treatment of Godfrey and Isgur. We find that the fit provided by the two-body Dirac model for the entire meson spectrum competes with the best fits to partial spectra provided by the others and does so with the smallest number of interaction functions without additional cutoff parameters necessary to make other approaches numerically tractable. We discuss the distinguishing features of our model that may account for the relative overall success of its fits. Note especially that in our approach for QCD, the resulting pion mass and associated Goldstone behavior depend sensitively on the preservation of relativistic couplings that are crucial for its success when solved nonperturbatively for the analogous two-body bound-states of QED.
hep-ph/0010352
Anatoly Kotikov
A. V. Kotikov, G. Parente
Q^2 evolution of parton distributions at small x
4 pages, latex. Talk presented at the Diffraction 2000 Workshop, Cetraro, September 2000
Nucl.Phys.Proc.Suppl. 99A (2001) 196-199
10.1016/S0920-5632(01)01333-0
null
hep-ph
null
We investigate the Q^2 evolution of parton distributions at small x values, obtained in the case of flat initial conditions. The results are in excellent agreement with deep inelastic scattering experimental data from HERA.
[ { "created": "Tue, 31 Oct 2000 20:22:24 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kotikov", "A. V.", "" ], [ "Parente", "G.", "" ] ]
We investigate the Q^2 evolution of parton distributions at small x values, obtained in the case of flat initial conditions. The results are in excellent agreement with deep inelastic scattering experimental data from HERA.
2108.01653
Edward Basso
Edward E. Basso, Daniel J.H. Chung
Computation of Gravitational Particle Production Using Adiabatic Invariants
37 pages, 5 figures
null
10.1007/JHEP11(2021)146
null
hep-ph gr-qc hep-th physics.comp-ph
http://creativecommons.org/licenses/by/4.0/
Analytic and numerical techniques are presented for computing gravitational production of scalar particles in the limit that the inflaton mass is much larger than the Hubble expansion rate at the end of inflation. These techniques rely upon adiabatic invariants and time modeling of a typical inflaton field which has slow and fast time variation components. A faster computation time for numerical integration is achieved via subtraction of slowly varying components that are ultimately exponentially suppressed. The fast oscillatory remnant results in production of scalar particles with a mass larger than the inflationary Hubble expansion rate through a mechanism analogous to perturbative particle scattering. An improved effective Boltzmann collision equation description of this particle production mechanism is developed. This model allows computation of the spectrum using only adiabatic invariants, avoiding the need to explicitly solve the inflaton equations of motion.
[ { "created": "Tue, 3 Aug 2021 17:49:42 GMT", "version": "v1" }, { "created": "Wed, 4 Aug 2021 17:50:02 GMT", "version": "v2" }, { "created": "Thu, 2 Sep 2021 17:21:49 GMT", "version": "v3" }, { "created": "Sun, 17 Oct 2021 17:26:16 GMT", "version": "v4" } ]
2021-12-08
[ [ "Basso", "Edward E.", "" ], [ "Chung", "Daniel J. H.", "" ] ]
Analytic and numerical techniques are presented for computing gravitational production of scalar particles in the limit that the inflaton mass is much larger than the Hubble expansion rate at the end of inflation. These techniques rely upon adiabatic invariants and time modeling of a typical inflaton field which has slow and fast time variation components. A faster computation time for numerical integration is achieved via subtraction of slowly varying components that are ultimately exponentially suppressed. The fast oscillatory remnant results in production of scalar particles with a mass larger than the inflationary Hubble expansion rate through a mechanism analogous to perturbative particle scattering. An improved effective Boltzmann collision equation description of this particle production mechanism is developed. This model allows computation of the spectrum using only adiabatic invariants, avoiding the need to explicitly solve the inflaton equations of motion.
1410.3347
Peng-fei Yin
Zhao-Huan Yu, Xiao-Jun Bi, Qi-Shu Yan, Peng-Fei Yin
Tau Portal Dark Matter models at the LHC
10 pages, 5 figures
null
10.1103/PhysRevD.91.035008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the Galactic Center gamma-ray excess in the Fermi-LAT data, we study the signatures of a class of tau portal dark matter (DM) models where DM particles preferentially couple to tau leptons at the LHC. We consider the constraints from the DM direct detection and investigate the sensitivity of the LHC to di-tau plus missing energy signatures. We find that the LHC with a high luminosity of 3000 fb$^{-1}$ can test the tau portal DM models with fermionic mediators in the mass range of $120\sim450$ GeV.
[ { "created": "Mon, 13 Oct 2014 15:22:45 GMT", "version": "v1" } ]
2015-06-23
[ [ "Yu", "Zhao-Huan", "" ], [ "Bi", "Xiao-Jun", "" ], [ "Yan", "Qi-Shu", "" ], [ "Yin", "Peng-Fei", "" ] ]
Motivated by the Galactic Center gamma-ray excess in the Fermi-LAT data, we study the signatures of a class of tau portal dark matter (DM) models where DM particles preferentially couple to tau leptons at the LHC. We consider the constraints from the DM direct detection and investigate the sensitivity of the LHC to di-tau plus missing energy signatures. We find that the LHC with a high luminosity of 3000 fb$^{-1}$ can test the tau portal DM models with fermionic mediators in the mass range of $120\sim450$ GeV.
hep-ph/9506263
Jim Ball
James S. Ball and Anthony Pantziris (University of Utah, Salt Lake City, UT)
High Energy Hadron-Nucleus Cross Sections and Their Extrapolation to Cosmic Ray Energies
8 pages, 9 postscript figures. This manuscript replaces a partial manuscript incorrectly submitted
Phys.Rev. D53 (1996) 1224-1231
10.1103/PhysRevD.53.1224
null
hep-ph
null
Old models of the scattering of composite systems based on the Glauber model of multiple diffraction are applied to hadron-nucleus scattering. We obtain an excellent fit with only two free parameters to the highest energy hadron-nucleus data available. Because of the quality of the fit and the simplicity of the model it is argued that it should continue to be reliable up to the highest cosmic ray energies. Logarithmic extrapolations of proton-proton and proton-antiproton data are used to calculate the proton-air cross sections at very high energy. Finally, it is observed that if the exponential behavior of the proton-antiproton diffraction peak continues into the few TeV energy range it will violate partial wave unitarity. We propose a simple modification that will guarantee unitarity throughout the cosmic ray energy region.
[ { "created": "Wed, 7 Jun 1995 23:57:49 GMT", "version": "v1" }, { "created": "Wed, 19 Jul 1995 22:34:46 GMT", "version": "v2" } ]
2009-10-28
[ [ "Ball", "James S.", "", "University of Utah, Salt Lake\n City, UT" ], [ "Pantziris", "Anthony", "", "University of Utah, Salt Lake\n City, UT" ] ]
Old models of the scattering of composite systems based on the Glauber model of multiple diffraction are applied to hadron-nucleus scattering. We obtain an excellent fit with only two free parameters to the highest energy hadron-nucleus data available. Because of the quality of the fit and the simplicity of the model it is argued that it should continue to be reliable up to the highest cosmic ray energies. Logarithmic extrapolations of proton-proton and proton-antiproton data are used to calculate the proton-air cross sections at very high energy. Finally, it is observed that if the exponential behavior of the proton-antiproton diffraction peak continues into the few TeV energy range it will violate partial wave unitarity. We propose a simple modification that will guarantee unitarity throughout the cosmic ray energy region.
1404.5835
Hiroshi Yokoya
Shinya Kanemura, Hiroshi Yokoya, Ya-Juan Zheng
Complementarity in direct searches for additional Higgs bosons at the LHC and the International Linear Collider
42 pages, 55 eps files; revised Figs. 1-3 due to the small change of parameters, added references, version for publication in Nuclear Physics B
Nucl.Phys. B886 (2014) 524-553
10.1016/j.nuclphysb.2014.07.007
UT-HET-087
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss complementarity of discovery reaches of heavier neutral Higgs bosons and charged Higgs bosons at the LHC and the International Linear Collider (ILC) in two Higgs doublet models (2HDMs). We perform a comprehensive analysis on their production and decay processes for all types of Yukawa interaction under the softly-broken discrete symmetry which is introduced to avoid flavour changing neutral currents, and we investigate parameter spaces of discovering additional Higgs bosons at the ILC beyond the LHC reach. We find that the 500 GeV run of the ILC with the integrated luminosity of 500 fb^{-1} shows an advantage for discovering the additional Higgs bosons in the region where the LHC cannot discover them with the integrated luminosity of 300 fb^{-1}. For the 1 TeV run of the ILC with the integrated luminosity of 1 ab^{-1}, production processes of an additional Higgs boson associated with the top quark can be useful as discovery channels in some parameter spaces where the LHC with the integrated luminosity of 3000 fb^{-1} cannot reach. It is emphasized that the complementary study at the LHC and the ILC is useful not only to survey additional Higgs bosons at the TeV scale, but also to discriminate types of Yukawa interaction in the 2HDM.
[ { "created": "Wed, 23 Apr 2014 14:33:52 GMT", "version": "v1" }, { "created": "Mon, 28 Jul 2014 01:00:38 GMT", "version": "v2" } ]
2014-07-30
[ [ "Kanemura", "Shinya", "" ], [ "Yokoya", "Hiroshi", "" ], [ "Zheng", "Ya-Juan", "" ] ]
We discuss complementarity of discovery reaches of heavier neutral Higgs bosons and charged Higgs bosons at the LHC and the International Linear Collider (ILC) in two Higgs doublet models (2HDMs). We perform a comprehensive analysis on their production and decay processes for all types of Yukawa interaction under the softly-broken discrete symmetry which is introduced to avoid flavour changing neutral currents, and we investigate parameter spaces of discovering additional Higgs bosons at the ILC beyond the LHC reach. We find that the 500 GeV run of the ILC with the integrated luminosity of 500 fb^{-1} shows an advantage for discovering the additional Higgs bosons in the region where the LHC cannot discover them with the integrated luminosity of 300 fb^{-1}. For the 1 TeV run of the ILC with the integrated luminosity of 1 ab^{-1}, production processes of an additional Higgs boson associated with the top quark can be useful as discovery channels in some parameter spaces where the LHC with the integrated luminosity of 3000 fb^{-1} cannot reach. It is emphasized that the complementary study at the LHC and the ILC is useful not only to survey additional Higgs bosons at the TeV scale, but also to discriminate types of Yukawa interaction in the 2HDM.
hep-ph/0307274
Vladimir Dzhunushaliev
Vladimir Dzhunushaliev
The colored flux tube
one misprint is correcetd
Hadronic J.Suppl. 19 (2004) 309-321
null
null
hep-ph hep-th
null
It is shown that in the SU(2) Yang - Mills - Higgs theory with broken gauge symmetry a flux tube solution filled with a color longitudinal electric field exists. The origin of the gauge symmetry breakdown for this case is discussed.
[ { "created": "Tue, 22 Jul 2003 08:40:06 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2003 03:47:00 GMT", "version": "v2" }, { "created": "Tue, 30 Nov 2004 07:11:27 GMT", "version": "v3" } ]
2007-05-23
[ [ "Dzhunushaliev", "Vladimir", "" ] ]
It is shown that in the SU(2) Yang - Mills - Higgs theory with broken gauge symmetry a flux tube solution filled with a color longitudinal electric field exists. The origin of the gauge symmetry breakdown for this case is discussed.
hep-ph/9702399
Frank Ferrari
Frank Ferrari
Non-perturbative aspects of (supersymmetric) gauge theories
2 pages, in french, to appear in the proceedings of the ``5eme journees des jeunes chercheurs,'' Autrans, 1996
null
null
LPTENS-97/01
hep-ph hep-th
null
At an elementary level, we present some non-perturbative aspects of non-abelian gauge theories in four dimensional space-time. Some rigorous results have been obtained in the framework of supersymmetric theories, and a very rich physics related to the strong-coupling dynamics of gauge fields has been discovered. Some of the new phenomena which appeared may play a significant role in future phenomenological models. However, quantitative computations in non-supersymmetric theories, like quantum chromodynamics, is out of reach for the moment.
[ { "created": "Sat, 22 Feb 1997 16:48:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ferrari", "Frank", "" ] ]
At an elementary level, we present some non-perturbative aspects of non-abelian gauge theories in four dimensional space-time. Some rigorous results have been obtained in the framework of supersymmetric theories, and a very rich physics related to the strong-coupling dynamics of gauge fields has been discovered. Some of the new phenomena which appeared may play a significant role in future phenomenological models. However, quantitative computations in non-supersymmetric theories, like quantum chromodynamics, is out of reach for the moment.
hep-ph/9708257
Tetsuo Hatsuda
T. Hatsuda (Univ. of Tsukuba)
Pade Improvement of the Free Energy in High Temperature QCD
Typos corrected. Minor changes in the text and references. To appear in Phys. Rev. D
Phys.Rev. D56 (1997) 8111-8114
10.1103/PhysRevD.56.8111
null
hep-ph hep-lat nucl-th
null
Pade approximants (PA's) are constructed from the perturbative coefficients of the free energy through O(g^5) in hot QCD. Pade summation is shown to reduce the renormalization-scale dependence substantially even at temperature (T) as low as 250 MeV. Also, PA's predict that the free energy does not deviate more than 10 % from the Stefan-Boltzmann limit for T > 250 MeV.
[ { "created": "Wed, 6 Aug 1997 04:09:50 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 1997 06:40:48 GMT", "version": "v2" } ]
2016-09-06
[ [ "Hatsuda", "T.", "", "Univ. of Tsukuba" ] ]
Pade approximants (PA's) are constructed from the perturbative coefficients of the free energy through O(g^5) in hot QCD. Pade summation is shown to reduce the renormalization-scale dependence substantially even at temperature (T) as low as 250 MeV. Also, PA's predict that the free energy does not deviate more than 10 % from the Stefan-Boltzmann limit for T > 250 MeV.
hep-ph/9905557
Jeff Forshaw
J. R. Forshaw
High-t Diffraction
3 pages, 1 figure. Talk presented at 7th International Workshop on Deep Inelastic Scattering, Zeuthen, Germany, April 1999. Revised version: references altered
Nucl.Phys.Proc.Suppl.79:311-314,1999
10.1016/S0920-5632(99)00708-2
CERN-TH/99-143
hep-ph
null
The study of those rapidity gap processes where a large momentum is transferred across the rapidity gap provides an ideal opportunity to understand the gap producing mechanism wholly within the framework of QCD perturbation theory. The current theoretical and experimental status of this `high-t diffraction' is reviewed.
[ { "created": "Mon, 31 May 1999 09:14:19 GMT", "version": "v1" }, { "created": "Tue, 1 Jun 1999 13:47:04 GMT", "version": "v2" } ]
2008-11-26
[ [ "Forshaw", "J. R.", "" ] ]
The study of those rapidity gap processes where a large momentum is transferred across the rapidity gap provides an ideal opportunity to understand the gap producing mechanism wholly within the framework of QCD perturbation theory. The current theoretical and experimental status of this `high-t diffraction' is reviewed.
2206.05004
Kazem Azizi
H. Sundu, S. S. Agaev, K. Azizi
Axial-vector and pseudoscalar tetraquarks $[ud][\bar{c}\bar{s}]$
14 Pages, 4 Figures and 2 Tables
null
10.1140/epjc/s10052-023-11339-8
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
Spectroscopic parameters and widths of the fully open-flavor axial-vector and pseudoscalar tetraquarks $X_{\mathrm{AV}}$ and $X_{\mathrm{PS}}$ with content $[ud][\overline{c}\overline{s}]$ are calculated by means of the QCD sum rule methods. Masses and current couplings of $X_{\mathrm{AV}}$ and $X_{ \mathrm{PS}}$ are found using two-point sum rule computations performed by taking into account various vacuum condensates up to dimension $10$. The full width of the axial-vector state $X_{\mathrm{AV}}$ is evaluated by including into analysis $S$-wave decay modes $X_{\mathrm{AV}}\to D^{\ast }(2010)^{-}K^{+}$, $\overline{D}^{\ast }(2007)^{0}K^{0}$, $D^{-}K^{\ast }(892)^{+}$, and $\overline{D}^{0}K^{\ast }(892)^{0}$. In the case of $X_{ \mathrm{PS}}$, we consider $S$-wave decay $X_{\mathrm{PS}}\to \overline{D} _{0}^{\ast }(2300)^{0}K^{0}$, and $P$-wave processes $X_{\mathrm{PS}}\to D^{-}K^{\ast}(892)^{+}$ and $X_{\mathrm{PS}}\to \overline{D} ^{0}K^{\ast}(892)^{0}$. To determine partial widths of these decay modes, we employ the QCD light-cone sum rule method and soft-meson approximation, which are necessary to estimate strong couplings at tetraquark-meson-meson vertices $X_{\mathrm{AV}}D^{-}D^{\ast }(2010)^{-}K^{+} $, etc. Our predictions for the mass $m_{\mathrm{AV}}=(2800 \pm 75)~\mathrm{MeV}$ and width $\Gamma_{\mathrm{AV}}=(58 \pm 10)~\mathrm{MeV}$ of the tetraquark $X_{ \mathrm{AV}}$, as well as results $m_{\mathrm{PS}}=(3000 \pm 60)~\mathrm{MeV} $ and $\Gamma_{\mathrm{PS}}=(65 \pm 12)~\mathrm{MeV}$ for the same parameters of $X_{\mathrm{PS}}$ may be useful in future experimental studies of multiquark hadrons.
[ { "created": "Fri, 10 Jun 2022 11:28:25 GMT", "version": "v1" }, { "created": "Wed, 21 Sep 2022 08:46:41 GMT", "version": "v2" }, { "created": "Tue, 28 Feb 2023 17:13:49 GMT", "version": "v3" } ]
2023-03-22
[ [ "Sundu", "H.", "" ], [ "Agaev", "S. S.", "" ], [ "Azizi", "K.", "" ] ]
Spectroscopic parameters and widths of the fully open-flavor axial-vector and pseudoscalar tetraquarks $X_{\mathrm{AV}}$ and $X_{\mathrm{PS}}$ with content $[ud][\overline{c}\overline{s}]$ are calculated by means of the QCD sum rule methods. Masses and current couplings of $X_{\mathrm{AV}}$ and $X_{ \mathrm{PS}}$ are found using two-point sum rule computations performed by taking into account various vacuum condensates up to dimension $10$. The full width of the axial-vector state $X_{\mathrm{AV}}$ is evaluated by including into analysis $S$-wave decay modes $X_{\mathrm{AV}}\to D^{\ast }(2010)^{-}K^{+}$, $\overline{D}^{\ast }(2007)^{0}K^{0}$, $D^{-}K^{\ast }(892)^{+}$, and $\overline{D}^{0}K^{\ast }(892)^{0}$. In the case of $X_{ \mathrm{PS}}$, we consider $S$-wave decay $X_{\mathrm{PS}}\to \overline{D} _{0}^{\ast }(2300)^{0}K^{0}$, and $P$-wave processes $X_{\mathrm{PS}}\to D^{-}K^{\ast}(892)^{+}$ and $X_{\mathrm{PS}}\to \overline{D} ^{0}K^{\ast}(892)^{0}$. To determine partial widths of these decay modes, we employ the QCD light-cone sum rule method and soft-meson approximation, which are necessary to estimate strong couplings at tetraquark-meson-meson vertices $X_{\mathrm{AV}}D^{-}D^{\ast }(2010)^{-}K^{+} $, etc. Our predictions for the mass $m_{\mathrm{AV}}=(2800 \pm 75)~\mathrm{MeV}$ and width $\Gamma_{\mathrm{AV}}=(58 \pm 10)~\mathrm{MeV}$ of the tetraquark $X_{ \mathrm{AV}}$, as well as results $m_{\mathrm{PS}}=(3000 \pm 60)~\mathrm{MeV} $ and $\Gamma_{\mathrm{PS}}=(65 \pm 12)~\mathrm{MeV}$ for the same parameters of $X_{\mathrm{PS}}$ may be useful in future experimental studies of multiquark hadrons.
1009.5415
Hiroshi Okada
Qing-Hong Cao, Shaaban Khalil, Ernest Ma, Hiroshi Okada
Observable T_7 Lepton Flavor Symmetry at the Large Hadron Collider
4 pages, 1 table, 1 figure; version accepted for publication in Physical Review Letters
Phys.Rev.Lett.106:131801,2011
10.1103/PhysRevLett.106.131801
ANL-HEP-PR-10-50, UCRHEP-T496
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
More often than not, models of flavor symmetry rely on the use of nonrenormalizable operators (in the guise of flavons) to accomplish the phenomenologically successful tribimaximal mixing of neutrinos. We show instead how a simple renormalizable two-parameter neutrino mass model of tribimaximal mixing can be constructed with the non-Abelian discrete symmetry T_7 and the gauging of B-L. This is also achieved without the addition of auxiliary symmetries and particles present in almost all other proposals. Most importantly, it is verifiable at the Large Hadron Collider.
[ { "created": "Tue, 28 Sep 2010 00:14:30 GMT", "version": "v1" }, { "created": "Tue, 8 Mar 2011 19:06:41 GMT", "version": "v2" } ]
2011-04-05
[ [ "Cao", "Qing-Hong", "" ], [ "Khalil", "Shaaban", "" ], [ "Ma", "Ernest", "" ], [ "Okada", "Hiroshi", "" ] ]
More often than not, models of flavor symmetry rely on the use of nonrenormalizable operators (in the guise of flavons) to accomplish the phenomenologically successful tribimaximal mixing of neutrinos. We show instead how a simple renormalizable two-parameter neutrino mass model of tribimaximal mixing can be constructed with the non-Abelian discrete symmetry T_7 and the gauging of B-L. This is also achieved without the addition of auxiliary symmetries and particles present in almost all other proposals. Most importantly, it is verifiable at the Large Hadron Collider.
hep-ph/0511350
Giulia Zanderighi
G.Zanderighi
Semi-numerical evaluation of one-loop corrections
Invited talk at LoopFest IV, during the 2005 International Linear Collider Physics and Detector Workshop, Snowmass, CO (Snowmass05), 3 pages
ECONFC0508141:ALCPG1918,2005
null
FERMILAB-CONF-05-529-T, CERN-PH-TH/2005-240
hep-ph
null
We present a semi-numerical method to compute one-loop corrections to processes involving many particles. We treat in detail cases with up to five external legs and massless internal propagators, although the method is more general.
[ { "created": "Wed, 30 Nov 2005 15:33:31 GMT", "version": "v1" } ]
2008-11-26
[ [ "Zanderighi", "G.", "" ] ]
We present a semi-numerical method to compute one-loop corrections to processes involving many particles. We treat in detail cases with up to five external legs and massless internal propagators, although the method is more general.
2206.08028
Le Tho Hue
T.T. Hong, N.H.T. Nha, T. Phong Nguyen, L. T. T. Phuong, L.T. Hue
Decays $h\to e_ae_b$, $e_b\to e_a\gamma$, and $(g-2)_{e,\mu}$ in a 3-3-1 model with inverse seesaw neutrinos
35 pages, new references were added, numerical investigations were changed, version accepted for publication in PTEP
PTEP 2022 (2022) 9, 093B05
10.1093/ptep/ptac109
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We will show that the 3-3-1 model with new heavy right handed neutrinos as $SU(3)_L$ singlets can explain simultaneously the lepton flavor violating decays of the SM-like Higgs boson, charged lepton flavor violating decays $e_b\rightarrow e_a\gamma$, and the electron $(g-2)_e$ anomalies under recent experimental data. The discrepancy of $(g-2)_{\mu}$ predicted by the model under consideration and that of the standard model can reach $10^{-9}$. The decay rates of the standard model-like Higgs boson $h\to \tau e, \tau\mu$ can reach the values of $\mathcal{O}(10^{-4})$.
[ { "created": "Thu, 16 Jun 2022 09:31:54 GMT", "version": "v1" }, { "created": "Wed, 31 Aug 2022 08:05:58 GMT", "version": "v2" } ]
2022-09-22
[ [ "Hong", "T. T.", "" ], [ "Nha", "N. H. T.", "" ], [ "Nguyen", "T. Phong", "" ], [ "Phuong", "L. T. T.", "" ], [ "Hue", "L. T.", "" ] ]
We will show that the 3-3-1 model with new heavy right handed neutrinos as $SU(3)_L$ singlets can explain simultaneously the lepton flavor violating decays of the SM-like Higgs boson, charged lepton flavor violating decays $e_b\rightarrow e_a\gamma$, and the electron $(g-2)_e$ anomalies under recent experimental data. The discrepancy of $(g-2)_{\mu}$ predicted by the model under consideration and that of the standard model can reach $10^{-9}$. The decay rates of the standard model-like Higgs boson $h\to \tau e, \tau\mu$ can reach the values of $\mathcal{O}(10^{-4})$.
hep-ph/9807517
Morimitsu Tanimoto
Morimitsu Tanimoto
Large Neutrino Flavor Mixings and Lepton Mass Matrices
16 pages, LaTex file, no figure Reort-no: EHU-98-08
null
null
null
hep-ph
null
Recent atmospheric neutrino data at Super-Kamiokande suggest the near-maximal flavor mixing. Models for the lepton mass matrix, which give the near-maximal flavor mixing, are discussed in this report. Mass matrix models are classified according to the mechanism providing the large flavor mixing, and those are reviewed briefly. "Naturalness" of the mass matrix is also discussed in order to select the neutrino mass matrix. Details of the mass matrix with the $S_3$ flavor symmetry are presented.
[ { "created": "Tue, 28 Jul 1998 03:37:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tanimoto", "Morimitsu", "" ] ]
Recent atmospheric neutrino data at Super-Kamiokande suggest the near-maximal flavor mixing. Models for the lepton mass matrix, which give the near-maximal flavor mixing, are discussed in this report. Mass matrix models are classified according to the mechanism providing the large flavor mixing, and those are reviewed briefly. "Naturalness" of the mass matrix is also discussed in order to select the neutrino mass matrix. Details of the mass matrix with the $S_3$ flavor symmetry are presented.
0912.5108
Stanislaw Mrowczynski
Stanislaw Mrowczynski and Berndt Muller
Quasi-linear transport approach to equilibration of quark-gluon plasmas
12 pages, explanatory comments added, to appear in Phys. Rev. D
Phys.Rev.D81:065021,2010
10.1103/PhysRevD.81.065021
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the transport equations of quark-gluon plasma in the quasi-linear approximation. The equations are either of the Balescu-Lenard or Fokker-Planck form. The plasma's dynamics is assumed to be governed by longitudinal chromoelectric fields. The isotropic plasma, which is stable, and the two-stream system, which is unstable, are considered in detail. A process of equilibration is briefly discussed in both cases. The peaks of the two-stream distribution are shown to rapidly dissolve in time.
[ { "created": "Sun, 27 Dec 2009 21:11:44 GMT", "version": "v1" }, { "created": "Mon, 11 Jan 2010 13:56:53 GMT", "version": "v2" }, { "created": "Mon, 1 Feb 2010 09:50:37 GMT", "version": "v3" } ]
2010-04-29
[ [ "Mrowczynski", "Stanislaw", "" ], [ "Muller", "Berndt", "" ] ]
We derive the transport equations of quark-gluon plasma in the quasi-linear approximation. The equations are either of the Balescu-Lenard or Fokker-Planck form. The plasma's dynamics is assumed to be governed by longitudinal chromoelectric fields. The isotropic plasma, which is stable, and the two-stream system, which is unstable, are considered in detail. A process of equilibration is briefly discussed in both cases. The peaks of the two-stream distribution are shown to rapidly dissolve in time.
0907.0043
Vi Nham Tram
Vi-Nham Tram (LBL, Berkeley), Francois Arleo (Annecy, LAPTH)
Global analysis of J/psi suppression in cold nuclear matter
6 pages, 3 figures To appear in the proceedings of 3rd International Conference On Hard And Electromagnetic Probes Of High-Energy Nuclear Collisions (HP2008) Eur.Phys.J.C
Eur.Phys.J.C61:847-852,2009
10.1140/epjc/s10052-009-0864-y
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Interpreting the J/psi suppression reported in nucleus--nucleus collisions at SPS and RHIC requires the quantitative understanding of cold nuclear matter effects, such as the inelastic rescattering of J/psi states in nuclei or the nuclear modification of parton densities. With respect to our former Glauber analysis, we include in the present work the new PHENIX d--Au measurements, and analyze as well all existing data using the EPS08 nuclear parton densities recently released. The largest suppression reported in the new PHENIX analysis leads in turn to an increase of sigma from 3.5 +/- 0.3 mb to 5.4 +/- 2.5 mb using proton PDF. The stronger x-dependence of the G^{A}/G^p ratio in EPS08 as compared to e.g. EKS98 shifts the cross section towards larger values at fixed target energies (x_2 ~ 0.1) while decreasing somehow the value extracted at RHIC (x_2 ~10^{-2}).
[ { "created": "Wed, 1 Jul 2009 00:18:25 GMT", "version": "v1" } ]
2009-07-10
[ [ "Tram", "Vi-Nham", "", "LBL, Berkeley" ], [ "Arleo", "Francois", "", "Annecy, LAPTH" ] ]
Interpreting the J/psi suppression reported in nucleus--nucleus collisions at SPS and RHIC requires the quantitative understanding of cold nuclear matter effects, such as the inelastic rescattering of J/psi states in nuclei or the nuclear modification of parton densities. With respect to our former Glauber analysis, we include in the present work the new PHENIX d--Au measurements, and analyze as well all existing data using the EPS08 nuclear parton densities recently released. The largest suppression reported in the new PHENIX analysis leads in turn to an increase of sigma from 3.5 +/- 0.3 mb to 5.4 +/- 2.5 mb using proton PDF. The stronger x-dependence of the G^{A}/G^p ratio in EPS08 as compared to e.g. EKS98 shifts the cross section towards larger values at fixed target energies (x_2 ~ 0.1) while decreasing somehow the value extracted at RHIC (x_2 ~10^{-2}).
hep-ph/0011177
Pran Nath
Pran Nath
Physics From Extra Dimensions
Based on an invited review talk at the conference NANPino-2000 at Dubna, Russia, July 19-22,2000; 18 pages, Latex including 2 figures; Revised version with additional references, text unchanged
Part.Nucl.Lett.104:7-19,2001
null
null
hep-ph hep-th
null
A brief review of the recent developments in the physics from extra dimensions is given with a focus on the effects of Kaluza-Klein excitations in the Standard Model sector. It is shown that the current accurate data on the Fermi constant and on other electro-weak parameters puts a lower bound on the scale of extra dimensions of $\sim$ 3 TeV, and thus the observation of such dimensions lies beyond the reach of accelerators in the near future. The correction to the anomalous magnetic moment of the muon from extra dimensions is discussed and one finds that with the current limit on the scale of extra dimensions from the Fermi constant, the correction to $g_{\mu}-2$ does not compete with the potentially large contributions from the supersymmetric electro-weak correction. The possibility of generating Kaluza-Klein excitations associated with large radius compactifications at the LHC is discussed. It is shown that if such excitations are indeed produced their resonance structure will encode information on the number of compactified dimensions as well as on the nature of the specific orbifold compactification. A brief discussion of difficulties such as rapid proton decay that one encounters in theories with large radius compactifications is given.
[ { "created": "Tue, 14 Nov 2000 12:50:44 GMT", "version": "v1" }, { "created": "Wed, 6 Dec 2000 10:49:11 GMT", "version": "v2" } ]
2014-11-17
[ [ "Nath", "Pran", "" ] ]
A brief review of the recent developments in the physics from extra dimensions is given with a focus on the effects of Kaluza-Klein excitations in the Standard Model sector. It is shown that the current accurate data on the Fermi constant and on other electro-weak parameters puts a lower bound on the scale of extra dimensions of $\sim$ 3 TeV, and thus the observation of such dimensions lies beyond the reach of accelerators in the near future. The correction to the anomalous magnetic moment of the muon from extra dimensions is discussed and one finds that with the current limit on the scale of extra dimensions from the Fermi constant, the correction to $g_{\mu}-2$ does not compete with the potentially large contributions from the supersymmetric electro-weak correction. The possibility of generating Kaluza-Klein excitations associated with large radius compactifications at the LHC is discussed. It is shown that if such excitations are indeed produced their resonance structure will encode information on the number of compactified dimensions as well as on the nature of the specific orbifold compactification. A brief discussion of difficulties such as rapid proton decay that one encounters in theories with large radius compactifications is given.
1507.00654
Andrew Long
Andrew J. Long, Hiren H. Patel, and Mark Trodden
The Electroweak Vacuum Angle at Finite Temperature and Implications for Baryogenesis
17 pages, 2 figures
Phys. Rev. D 92, 043513 (2015)
10.1103/PhysRevD.92.043513
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We initiate a study of cosmological implications of sphaleron-mediated CP-violation arising from the electroweak vacuum angle under the reasonable assumption that the semiclassical suppression is lifted at finite temperature. In this article, we explore the implications for existing scenarios of baryogenesis. Many compelling models of baryogenesis rely on electroweak sphalerons to relax a $(B+L)$ charge asymmetry. Depending on the sign of the CP-violating parameter, it is shown that the erasure of positive $(B+L)$ will proceed more or less quickly than the relaxation of negative $(B+L)$. This is a higher order effect in the kinetic equation for baryon number, which we derive here through order $n_{B+L}^2$. Its impact on known baryogenesis models therefore seems minor, since phenomenologically $n_{B+L}$ is much smaller than the entropy density. However, there remains an intriguing unexplored possibility that baryogenesis could be achieved with the vacuum angle alone providing the required CP-violation.
[ { "created": "Thu, 2 Jul 2015 16:43:34 GMT", "version": "v1" } ]
2015-08-26
[ [ "Long", "Andrew J.", "" ], [ "Patel", "Hiren H.", "" ], [ "Trodden", "Mark", "" ] ]
We initiate a study of cosmological implications of sphaleron-mediated CP-violation arising from the electroweak vacuum angle under the reasonable assumption that the semiclassical suppression is lifted at finite temperature. In this article, we explore the implications for existing scenarios of baryogenesis. Many compelling models of baryogenesis rely on electroweak sphalerons to relax a $(B+L)$ charge asymmetry. Depending on the sign of the CP-violating parameter, it is shown that the erasure of positive $(B+L)$ will proceed more or less quickly than the relaxation of negative $(B+L)$. This is a higher order effect in the kinetic equation for baryon number, which we derive here through order $n_{B+L}^2$. Its impact on known baryogenesis models therefore seems minor, since phenomenologically $n_{B+L}$ is much smaller than the entropy density. However, there remains an intriguing unexplored possibility that baryogenesis could be achieved with the vacuum angle alone providing the required CP-violation.
0911.1120
Stephen West
Lawrence J. Hall, Karsten Jedamzik, John March-Russell, and Stephen M. West
Freeze-In Production of FIMP Dark Matter
30 pages, 7 figures, PDFLaTex. References added
JHEP 1003:080,2010
10.1007/JHEP03(2010)080
OUTP-09-18-P, UCB-PTH-09/32
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an alternate, calculable mechanism of dark matter genesis, "thermal freeze-in," involving a Feebly Interacting Massive Particle (FIMP) interacting so feebly with the thermal bath that it never attains thermal equilibrium. As with the conventional "thermal freeze-out" production mechanism, the relic abundance reflects a combination of initial thermal distributions together with particle masses and couplings that can be measured in the laboratory or astrophysically. The freeze-in yield is IR dominated by low temperatures near the FIMP mass and is independent of unknown UV physics, such as the reheat temperature after inflation. Moduli and modulinos of string theory compactifications that receive mass from weak-scale supersymmetry breaking provide implementations of the freeze-in mechanism, as do models that employ Dirac neutrino masses or GUT-scale-suppressed interactions. Experimental signals of freeze-in and FIMPs can be spectacular, including the production of new metastable coloured or charged particles at the LHC as well as the alteration of big bang nucleosynthesis.
[ { "created": "Thu, 5 Nov 2009 20:41:44 GMT", "version": "v1" }, { "created": "Tue, 8 Dec 2009 18:32:29 GMT", "version": "v2" } ]
2014-11-20
[ [ "Hall", "Lawrence J.", "" ], [ "Jedamzik", "Karsten", "" ], [ "March-Russell", "John", "" ], [ "West", "Stephen M.", "" ] ]
We propose an alternate, calculable mechanism of dark matter genesis, "thermal freeze-in," involving a Feebly Interacting Massive Particle (FIMP) interacting so feebly with the thermal bath that it never attains thermal equilibrium. As with the conventional "thermal freeze-out" production mechanism, the relic abundance reflects a combination of initial thermal distributions together with particle masses and couplings that can be measured in the laboratory or astrophysically. The freeze-in yield is IR dominated by low temperatures near the FIMP mass and is independent of unknown UV physics, such as the reheat temperature after inflation. Moduli and modulinos of string theory compactifications that receive mass from weak-scale supersymmetry breaking provide implementations of the freeze-in mechanism, as do models that employ Dirac neutrino masses or GUT-scale-suppressed interactions. Experimental signals of freeze-in and FIMPs can be spectacular, including the production of new metastable coloured or charged particles at the LHC as well as the alteration of big bang nucleosynthesis.
2211.12906
Eberhard Klempt
Volker Burkert, Eberhard Klempt and Ulrike Thoma
Light-quark baryons
11 pages, 7 figures, 2 tables
null
null
null
hep-ph nucl-ex
http://creativecommons.org/licenses/by-nc-sa/4.0/
This is a contribution to the review "50 Years of Quantum Chromdynamics" edited by F. Gross and E. Klempt [arXiv:2212.11107], to be published in EPJC. The contribution reviews the new baryon resonances derived from photoproduction experiments. Implications of the new results for the interpretation of baryons are discussed.
[ { "created": "Wed, 23 Nov 2022 12:21:30 GMT", "version": "v1" }, { "created": "Thu, 24 Nov 2022 17:55:13 GMT", "version": "v2" } ]
2022-12-27
[ [ "Burkert", "Volker", "" ], [ "Klempt", "Eberhard", "" ], [ "Thoma", "Ulrike", "" ] ]
This is a contribution to the review "50 Years of Quantum Chromdynamics" edited by F. Gross and E. Klempt [arXiv:2212.11107], to be published in EPJC. The contribution reviews the new baryon resonances derived from photoproduction experiments. Implications of the new results for the interpretation of baryons are discussed.
hep-ph/9807533
Qiao Cong Feng
Hong-an Peng, Cong-feng Qiao, Jia-sheng Xu and Zhen-min He
Demonstration of the double Q^2-rescaling model
19 page, RevTex, 5 figures in postscript
Commun.Theor.Phys.32:443-452,1999
10.1088/0253-6102/32/3/443
PKU-TP-98-31
hep-ph
null
In this paper we have demonstrated the double Q^2-rescaling model (DQ^2RM) of parton distribution functions of nucleon bounded in nucleus. With different x-region of l-A deep inelastic scattering process we take different approach: in high x-region (0.1\le x\le 0.7) we use the distorted QCD vacuum model which resulted from topologically multi -connected domain vacuum structure of nucleus; in low x-region (10^{-4}\le x\le10^{-3}) we adopt the Glauber (Mueller) multi- scattering formula for gluon coherently rescattering in nucleus. From these two approach we justified the rescaling parton distribution functions in bound nucleon are in agreement well with those we got from DQ^2RM, thus the validity for this phenomenologically model are demonstrated.
[ { "created": "Wed, 29 Jul 1998 10:02:41 GMT", "version": "v1" } ]
2018-01-17
[ [ "Peng", "Hong-an", "" ], [ "Qiao", "Cong-feng", "" ], [ "Xu", "Jia-sheng", "" ], [ "He", "Zhen-min", "" ] ]
In this paper we have demonstrated the double Q^2-rescaling model (DQ^2RM) of parton distribution functions of nucleon bounded in nucleus. With different x-region of l-A deep inelastic scattering process we take different approach: in high x-region (0.1\le x\le 0.7) we use the distorted QCD vacuum model which resulted from topologically multi -connected domain vacuum structure of nucleus; in low x-region (10^{-4}\le x\le10^{-3}) we adopt the Glauber (Mueller) multi- scattering formula for gluon coherently rescattering in nucleus. From these two approach we justified the rescaling parton distribution functions in bound nucleon are in agreement well with those we got from DQ^2RM, thus the validity for this phenomenologically model are demonstrated.
1312.3558
Damian Ejlli
Damian Ejlli and Alexander D. Dolgov
CMB constraints on mass and coupling constant of light pseudoscalar particles
Published version
Phys. Rev. D 90, 063514 (2014)
10.1103/PhysRevD.90.063514
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transformation of CMB photons into light pseudoscalar particles at post big bang nucleosynthesis epoch is considered. Using the present day value of a large scale magnetic field to estimate it at earlier cosmological epochs, the oscillation probability of photons into light pseudoscalar particles with an account of coherence breaking in cosmological plasma is calculated. Demanding that the photon transformation does not lead to an exceedingly large CMB spectral distortion and temperature anisotropy, the constraints on the coupling constant of axion like particles to photons, $ g_{\phi\gamma} B \lesssim (10^{-15} - 10^{-12}) \textrm{nG}\times \textrm{GeV}^{-1}$, are found for the axion like particle mass in the interval $10^{-25}$ eV $\lesssim m_{\phi}\lesssim 10^{-5}$ eV, where $B$ is the strength of the large scale magnetic field at the present time. Our results update the previously obtained ones since we use the density matrix formalism which is more accurate than the wave function approximation for the description of oscillations with an essential coherence breaking. In the axion like particle mass range $10^{-25}$ eV $\lesssim m_{\phi}\lesssim 10^{-14}$ eV, weaker limits, by at least 2 orders of magnitude $g_{\phi\gamma} B \lesssim 10^{-11}\textrm{nG}\times \textrm{GeV}^{-1}$, are obtained in comparison with the wave function approximation. In the mass range $10^{-14}$ eV $\lesssim m_{\phi}\lesssim 10^{-5}$ eV, on the other hand, limits that are stronger, by more than an order of magnitude are obtained. Our results are derived by using upper limits on spectral distortion parameter $\mu$ and temperature anisotropy $\Delta T/T$ found by COBE and expected sensitivities by PIXIE/PRISM.
[ { "created": "Thu, 12 Dec 2013 17:32:40 GMT", "version": "v1" }, { "created": "Mon, 1 Sep 2014 11:43:37 GMT", "version": "v2" }, { "created": "Mon, 15 Sep 2014 11:12:52 GMT", "version": "v3" } ]
2014-09-16
[ [ "Ejlli", "Damian", "" ], [ "Dolgov", "Alexander D.", "" ] ]
Transformation of CMB photons into light pseudoscalar particles at post big bang nucleosynthesis epoch is considered. Using the present day value of a large scale magnetic field to estimate it at earlier cosmological epochs, the oscillation probability of photons into light pseudoscalar particles with an account of coherence breaking in cosmological plasma is calculated. Demanding that the photon transformation does not lead to an exceedingly large CMB spectral distortion and temperature anisotropy, the constraints on the coupling constant of axion like particles to photons, $ g_{\phi\gamma} B \lesssim (10^{-15} - 10^{-12}) \textrm{nG}\times \textrm{GeV}^{-1}$, are found for the axion like particle mass in the interval $10^{-25}$ eV $\lesssim m_{\phi}\lesssim 10^{-5}$ eV, where $B$ is the strength of the large scale magnetic field at the present time. Our results update the previously obtained ones since we use the density matrix formalism which is more accurate than the wave function approximation for the description of oscillations with an essential coherence breaking. In the axion like particle mass range $10^{-25}$ eV $\lesssim m_{\phi}\lesssim 10^{-14}$ eV, weaker limits, by at least 2 orders of magnitude $g_{\phi\gamma} B \lesssim 10^{-11}\textrm{nG}\times \textrm{GeV}^{-1}$, are obtained in comparison with the wave function approximation. In the mass range $10^{-14}$ eV $\lesssim m_{\phi}\lesssim 10^{-5}$ eV, on the other hand, limits that are stronger, by more than an order of magnitude are obtained. Our results are derived by using upper limits on spectral distortion parameter $\mu$ and temperature anisotropy $\Delta T/T$ found by COBE and expected sensitivities by PIXIE/PRISM.
hep-ph/0508022
Ulrich Ellwanger
Ulrich Ellwanger, Cyril Hugonie
NMHDECAY 2.0: An updated program for Sparticle masses, Higgs masses, couplings and decay widths in the NMSSM
23 pages, names of the Higgs and Neutralino mixing mass matrices changed in order to agree with SLHA2
Comput.Phys.Commun.175:290-303,2006
10.1016/j.cpc.2006.04.004
LPT Orsay 05-52
hep-ph
null
We describe the the improved properties of the NMHDECAY program, that is designed to compute Higgs and sparticle masses and Higgs decay widths in the NMSSM. In the version 2.0, Higgs decays into squarks and sleptons are included, accompagnied by a calculation of the squark, gluino and slepton spectrum and tests against constraints from LEP and the Tevatron. Further radiative corrections are included in the Higgs mass calculation. A link to MicrOMEGAs allows to compute the dark matter relic density, and a rough (lowest order) calculation of the BR(s -> b gamma) is performed.
[ { "created": "Mon, 1 Aug 2005 16:01:08 GMT", "version": "v1" }, { "created": "Tue, 6 Feb 2007 13:27:19 GMT", "version": "v2" } ]
2011-06-02
[ [ "Ellwanger", "Ulrich", "" ], [ "Hugonie", "Cyril", "" ] ]
We describe the the improved properties of the NMHDECAY program, that is designed to compute Higgs and sparticle masses and Higgs decay widths in the NMSSM. In the version 2.0, Higgs decays into squarks and sleptons are included, accompagnied by a calculation of the squark, gluino and slepton spectrum and tests against constraints from LEP and the Tevatron. Further radiative corrections are included in the Higgs mass calculation. A link to MicrOMEGAs allows to compute the dark matter relic density, and a rough (lowest order) calculation of the BR(s -> b gamma) is performed.
hep-ph/9603346
Wim deBoer
A.V. Gladyshev, D.I. Kazakov, W. de Boer, G. Burkart, R. Ehret
MSSM Predictions of the neutral Higgs boson masses and LEP II production cross sections
latex + 6 eps figs, 22 pages, final version
Nucl.Phys. B498 (1997) 3-27
10.1016/S0550-3213(97)00253-8
IEKP-KA/96-03, JINR E2-95-401
hep-ph
null
Within the framework of the Minimal Supersymmetric Standard Model (MSSM) the Higgs masses and LEP II production cross sections are calculated for a wide range of the parameter space. In addition, the parameter space restricted by unification, electroweak symmetry breaking and other low energy constraints is considered in detail, in which case the masses of all SUSY partners can be estimated, so that their contributions to the radiative corrections can be calculated. Explicit analytical formulae for these contribution are derived. The radiative corrections from the Yukawa couplings of the third generation are found to dominate over the contributions from charginos and neutralinos. Large Higgs mass uncertainties are due to the top mass uncertainty and the unknown sign of the Higgs mixing parameter. For the low tanb scenario the mass of the lightest Higgs is found to be below 103 GeV for a top mass below 190 GeV. The cross section at a LEP energy of 192 GeV is sufficient to find or exclude this low tanb scenario for a top mass below 180 GeV. For the high tanb scenario only a small fraction of the parameter space can be covered, since the Higgs mass is predicted between 105 and 125 GeV in most cases. At the theoretically possible LEP II energy of 205 GeV part of the parameter space for the large tanb scenario would be accessible.
[ { "created": "Tue, 19 Mar 1996 16:22:00 GMT", "version": "v1" }, { "created": "Fri, 29 Mar 1996 14:23:30 GMT", "version": "v2" }, { "created": "Mon, 22 Apr 1996 15:09:02 GMT", "version": "v3" }, { "created": "Sat, 6 Jul 1996 18:04:15 GMT", "version": "v4" }, { "created": "Sun, 2 Feb 1997 18:47:51 GMT", "version": "v5" }, { "created": "Tue, 6 Feb 2001 12:23:47 GMT", "version": "v6" } ]
2009-10-28
[ [ "Gladyshev", "A. V.", "" ], [ "Kazakov", "D. I.", "" ], [ "de Boer", "W.", "" ], [ "Burkart", "G.", "" ], [ "Ehret", "R.", "" ] ]
Within the framework of the Minimal Supersymmetric Standard Model (MSSM) the Higgs masses and LEP II production cross sections are calculated for a wide range of the parameter space. In addition, the parameter space restricted by unification, electroweak symmetry breaking and other low energy constraints is considered in detail, in which case the masses of all SUSY partners can be estimated, so that their contributions to the radiative corrections can be calculated. Explicit analytical formulae for these contribution are derived. The radiative corrections from the Yukawa couplings of the third generation are found to dominate over the contributions from charginos and neutralinos. Large Higgs mass uncertainties are due to the top mass uncertainty and the unknown sign of the Higgs mixing parameter. For the low tanb scenario the mass of the lightest Higgs is found to be below 103 GeV for a top mass below 190 GeV. The cross section at a LEP energy of 192 GeV is sufficient to find or exclude this low tanb scenario for a top mass below 180 GeV. For the high tanb scenario only a small fraction of the parameter space can be covered, since the Higgs mass is predicted between 105 and 125 GeV in most cases. At the theoretically possible LEP II energy of 205 GeV part of the parameter space for the large tanb scenario would be accessible.
1610.06125
Sergey Koshkarev
Sergey Koshkarev
Production of the Doubly Heavy Baryons, $B_c$ Meson and the All-charm Tetraquark at AFTER@LHC with Double Intrinsic Heavy Mechanism
Version 2
Acta Physica Polonica B, Vol.48 No.2, p.163 (2017)
10.5506/APhysPolB.48.163
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the paper we discuss contribution of the doubly intrinsic heavy mechanism into the production of $B_c$ meson, the doubly heavy baryons and the all-charm tetraquark at a future fixed-target experiment at the LHC (AFTER@LHC). The production cross sections and the mean values of Feynman-x for the finale states are presented.
[ { "created": "Wed, 19 Oct 2016 17:48:48 GMT", "version": "v1" }, { "created": "Tue, 1 Nov 2016 17:16:49 GMT", "version": "v2" }, { "created": "Sun, 5 Mar 2017 22:22:23 GMT", "version": "v3" }, { "created": "Wed, 15 Mar 2017 12:24:06 GMT", "version": "v4" } ]
2017-03-16
[ [ "Koshkarev", "Sergey", "" ] ]
In the paper we discuss contribution of the doubly intrinsic heavy mechanism into the production of $B_c$ meson, the doubly heavy baryons and the all-charm tetraquark at a future fixed-target experiment at the LHC (AFTER@LHC). The production cross sections and the mean values of Feynman-x for the finale states are presented.
hep-ph/0111308
Juan E. Palomar
J. E. Palomar, S. Hirenzaki, E. Oset
Chiral loops and VMD in the V->PPgamma decays
16 pages, 4 figures. To be published in Nucl. Phys. A
Nucl.Phys. A707 (2002) 161-172
10.1016/S0375-9474(02)00960-0
FTUV-01-1123 ; IFIC-01-1123
hep-ph nucl-th
null
We evaluate radiative decays of $\rho$ and $\omega$ going to two neutral mesons, $\pi^{0} \pi^{0}$ and $\pi^{0} \eta$. We use the sequential vector decay mechanisms in addition to chiral loops and $\rho$-$\omega$ mixing. The chiral loops are obtained using elements of $U\chi PT$ successfully applied in the study of meson-meson interactions up to 1.2 GeV. The chiral loops are found very important in the case of the $\rho \to \pi^{0} \pi^{0} \gamma$ decay and small in the other cases. A good agreement with present measurements of $\rho \to \pi^{0} \pi^{0} \gamma$ and $\omega \to \pi^{0} \pi^{0}\gamma$ is obtained and predictions are made for the other decays where the rates obtained are rather small.
[ { "created": "Fri, 23 Nov 2001 17:58:23 GMT", "version": "v1" }, { "created": "Thu, 18 Apr 2002 10:05:52 GMT", "version": "v2" } ]
2009-11-07
[ [ "Palomar", "J. E.", "" ], [ "Hirenzaki", "S.", "" ], [ "Oset", "E.", "" ] ]
We evaluate radiative decays of $\rho$ and $\omega$ going to two neutral mesons, $\pi^{0} \pi^{0}$ and $\pi^{0} \eta$. We use the sequential vector decay mechanisms in addition to chiral loops and $\rho$-$\omega$ mixing. The chiral loops are obtained using elements of $U\chi PT$ successfully applied in the study of meson-meson interactions up to 1.2 GeV. The chiral loops are found very important in the case of the $\rho \to \pi^{0} \pi^{0} \gamma$ decay and small in the other cases. A good agreement with present measurements of $\rho \to \pi^{0} \pi^{0} \gamma$ and $\omega \to \pi^{0} \pi^{0}\gamma$ is obtained and predictions are made for the other decays where the rates obtained are rather small.
1808.02431
Sergey Godunov
S.I. Godunov, V.A. Novikov, M.I. Vysotsky, E.V. Zhemchugov
Dimuon resonance near 28 GeV and muon anomaly
11 pages, 2 figures, 2 tables
null
10.1134/S002136401906002X
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss if the resonance recently observed by CMS can be responsible for the deviation of the experimentally measured muon anomalous magnetic moment from the theoretical prediction.
[ { "created": "Tue, 7 Aug 2018 15:57:21 GMT", "version": "v1" } ]
2019-03-27
[ [ "Godunov", "S. I.", "" ], [ "Novikov", "V. A.", "" ], [ "Vysotsky", "M. I.", "" ], [ "Zhemchugov", "E. V.", "" ] ]
We discuss if the resonance recently observed by CMS can be responsible for the deviation of the experimentally measured muon anomalous magnetic moment from the theoretical prediction.
hep-ph/9508298
null
Jonathan L. Rosner
Table-Top Time Reversal Violation
11 pages, latex, 1 uuencoded figure (material and references added)
Am.J.Phys.64:982-985,1996
10.1119/1.18472
EFI-95-51
hep-ph
null
Many electrical and mechanical systems with two normal modes are appropriate for illustrating the quantum mechanics of neutral kaons. The illustration of CP- or time-reversal-violation in the neutral kaon system by mechanical or electrical analogues is more subtle. Some possibilities which could be realized in a table-top demonstration are suggested.
[ { "created": "Tue, 15 Aug 1995 22:15:54 GMT", "version": "v1" }, { "created": "Wed, 27 Sep 1995 16:57:17 GMT", "version": "v2" }, { "created": "Thu, 28 Sep 1995 15:30:12 GMT", "version": "v3" }, { "created": "Wed, 11 Oct 1995 18:13:02 GMT", "version": "v4" } ]
2008-11-26
[ [ "Rosner", "Jonathan L.", "" ] ]
Many electrical and mechanical systems with two normal modes are appropriate for illustrating the quantum mechanics of neutral kaons. The illustration of CP- or time-reversal-violation in the neutral kaon system by mechanical or electrical analogues is more subtle. Some possibilities which could be realized in a table-top demonstration are suggested.
1809.09437
Massimo Mannarelli
Massimo Mannarelli
The improved Ginzburg-Landau technique
7 pages, 5 figures. Presented at QCD@Work - International Workshop on QCD Theory and Experiment 25-28 June 2018, Matera, Italy
null
10.1051/epjconf/201819200021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss an innovative method for the description of inhomogeneous phases designed to improve the standard Ginzburg-Landau expansion. The method is characterized by two key ingredients. The first one is a moving average of the order parameter designed to account for the long-wavelength modulations of the condensate. The second one is a sum of the high frequency modes, to improve the description of the phase transition to the restored phase. The method is applied to compare the free energies of 1D and 2D inhomogeneous structures arising in the chirally symmetric broken phase.
[ { "created": "Tue, 25 Sep 2018 12:47:01 GMT", "version": "v1" } ]
2018-12-05
[ [ "Mannarelli", "Massimo", "" ] ]
We discuss an innovative method for the description of inhomogeneous phases designed to improve the standard Ginzburg-Landau expansion. The method is characterized by two key ingredients. The first one is a moving average of the order parameter designed to account for the long-wavelength modulations of the condensate. The second one is a sum of the high frequency modes, to improve the description of the phase transition to the restored phase. The method is applied to compare the free energies of 1D and 2D inhomogeneous structures arising in the chirally symmetric broken phase.
hep-ph/9512446
Howard Haber
M. Carena, H.E. Haber, and C.E.M. Wagner
Four-Generation Low Energy Supersymmetry with a Light Top Quark
24 pages, LaTeX with psfig and scipp style files, ps file available at ftp://scipp.ucsc.edu/pub/haber/fourgen.ps
Nucl.Phys.B472:55-78,1996
10.1016/0550-3213(96)00257-X
CERN-TH/95-311 and SCIPP 95/44
hep-ph
null
A supersymmetric model with four generations is proposed, in which the top quark is approximately degenerate in mass with the $W^{\pm}$ gauge boson, $m_t\simeq m_W$, leading to values of $R_b$ in better agreement with the present experimental data than in the Standard Model. The model shares many of the good features of the minimal supersymmetric extension of the Standard Model (MSSM), such as the unification of gauge and Yukawa couplings at a common high-energy scale. The model differs from the MSSM by re-interpreting the Tevatron ``top-quark'' events as the production of the fourth generation quark $t\pri$, which decays dominantly to $bW^+$. The top quark decays primarily into supersymmetric particles, $t\rta\widetilde t\widetilde\chi^0_1$, with $\widetilde t\rta c\widetilde\chi^0_1$, thereby evading previous searches. Light supersymmetric particles are predicted to lie in the mass range between 25 and 70 GeV, which together with the fourth generation leptons provide a rich spectrum of new physics which can be probed at LEP-2 and the Tevatron.
[ { "created": "Mon, 1 Jan 1996 05:56:15 GMT", "version": "v1" } ]
2008-11-26
[ [ "Carena", "M.", "" ], [ "Haber", "H. E.", "" ], [ "Wagner", "C. E. M.", "" ] ]
A supersymmetric model with four generations is proposed, in which the top quark is approximately degenerate in mass with the $W^{\pm}$ gauge boson, $m_t\simeq m_W$, leading to values of $R_b$ in better agreement with the present experimental data than in the Standard Model. The model shares many of the good features of the minimal supersymmetric extension of the Standard Model (MSSM), such as the unification of gauge and Yukawa couplings at a common high-energy scale. The model differs from the MSSM by re-interpreting the Tevatron ``top-quark'' events as the production of the fourth generation quark $t\pri$, which decays dominantly to $bW^+$. The top quark decays primarily into supersymmetric particles, $t\rta\widetilde t\widetilde\chi^0_1$, with $\widetilde t\rta c\widetilde\chi^0_1$, thereby evading previous searches. Light supersymmetric particles are predicted to lie in the mass range between 25 and 70 GeV, which together with the fourth generation leptons provide a rich spectrum of new physics which can be probed at LEP-2 and the Tevatron.
0801.2072
Gennady Kozlov
G.A. Kozlov
Bose-Einstein correlations and the stochastic scale of light hadrons emitter source
16 pages
null
10.1142/9789812834959_0010
null
hep-ph
null
Based on quantum field theory at finite temperature we carried out new results for two-particle Bose-Einstein correlation (BEC) function ${C_2}(Q)$ in case of light hadrons. The important parameters of BEC function related to the size of the emitting source, mean multiplicity, stochastic forces range with the particle energy and mass dependence, and the temperature of the source are obtained for the first time. Not only the correlation between identical hadrons are explored but even the off-correlation between non-identical particles are proposed. The correlations of two bosons in 4-momentum space presented in this paper offer useful and instructive complimentary viewpoints to theoretical and experimental works in multiparticle femtoscopy and interferometry measurements at hadron colliders. This paper is the first one to the next opening series of works concerning the searching of BEC with experimental data where the parameters above mentioned will be retrieved.
[ { "created": "Mon, 14 Jan 2008 13:16:01 GMT", "version": "v1" } ]
2017-08-23
[ [ "Kozlov", "G. A.", "" ] ]
Based on quantum field theory at finite temperature we carried out new results for two-particle Bose-Einstein correlation (BEC) function ${C_2}(Q)$ in case of light hadrons. The important parameters of BEC function related to the size of the emitting source, mean multiplicity, stochastic forces range with the particle energy and mass dependence, and the temperature of the source are obtained for the first time. Not only the correlation between identical hadrons are explored but even the off-correlation between non-identical particles are proposed. The correlations of two bosons in 4-momentum space presented in this paper offer useful and instructive complimentary viewpoints to theoretical and experimental works in multiparticle femtoscopy and interferometry measurements at hadron colliders. This paper is the first one to the next opening series of works concerning the searching of BEC with experimental data where the parameters above mentioned will be retrieved.
1203.5106
Kathryn Zurek
Clifford Cheung, Michele Papucci, Kathryn M. Zurek
Higgs and Dark Matter Hints of an Oasis in the Desert
29 pages, 13 figures
null
10.1007/JHEP07(2012)105
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent LHC results suggest a standard model (SM)-like Higgs boson in the vicinity of 125 GeV with no clear indications yet of physics beyond the SM. At the same time, the SM is incomplete, since additional dynamics are required to accommodate cosmological dark matter (DM). In this paper we show that interactions between weak scale DM and the Higgs which are strong enough to yield a thermal relic abundance consistent with observation can easily destabilize the electroweak vacuum or drive the theory into a non-perturbative regime at a low scale. As a consequence, new physics--beyond the DM itself--must enter at a cutoff well below the Planck scale and in some cases as low as O(10 - 1000 TeV), a range relevant to indirect probes of flavor and CP violation. In addition, this cutoff is correlated with the DM mass and scattering cross-section in a parameter space which will be probed experimentally in the near term. Specifically, we consider the SM plus additional spin 0 or 1/2 states with singlet, triplet, or doublet electroweak quantum numbers and quartic or Yukawa couplings to the Higgs boson. We derive explicit expressions for the full two-loop RGEs and one-loop threshold corrections for these theories.
[ { "created": "Thu, 22 Mar 2012 20:00:03 GMT", "version": "v1" } ]
2015-06-04
[ [ "Cheung", "Clifford", "" ], [ "Papucci", "Michele", "" ], [ "Zurek", "Kathryn M.", "" ] ]
Recent LHC results suggest a standard model (SM)-like Higgs boson in the vicinity of 125 GeV with no clear indications yet of physics beyond the SM. At the same time, the SM is incomplete, since additional dynamics are required to accommodate cosmological dark matter (DM). In this paper we show that interactions between weak scale DM and the Higgs which are strong enough to yield a thermal relic abundance consistent with observation can easily destabilize the electroweak vacuum or drive the theory into a non-perturbative regime at a low scale. As a consequence, new physics--beyond the DM itself--must enter at a cutoff well below the Planck scale and in some cases as low as O(10 - 1000 TeV), a range relevant to indirect probes of flavor and CP violation. In addition, this cutoff is correlated with the DM mass and scattering cross-section in a parameter space which will be probed experimentally in the near term. Specifically, we consider the SM plus additional spin 0 or 1/2 states with singlet, triplet, or doublet electroweak quantum numbers and quartic or Yukawa couplings to the Higgs boson. We derive explicit expressions for the full two-loop RGEs and one-loop threshold corrections for these theories.
1807.09643
Kimiko Yamashita
Chao-Qiang Geng, Da Huang, Kimiko Yamashita
LHC Searches for Top-philic Kaluza-Klein Graviton
20 pages, 7 figures, 2 tables, revised version accepted by JHEP
JHEP 10 (2018) 046
10.1007/JHEP10(2018)046
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the phenomenology of a massive graviton $G$ with non-universal couplings to the Standard Model (SM) particles. Such a particle can arise as a warped Kaluza-Klein graviton from a framework of the Randall-Sundrum extra-dimension model. In particular, we consider a case in which $G$ is top-philic, i.e., $G$ interacts strongly with the right-handed top quark, resulting in the large top-loop contributions to its production via the gluon fusion and its decays to the SM gauge bosons. We take into account the constraints from the current 13 TeV LHC data on the channels of $t\bar{t}$, $\gamma\gamma$, $jj (gg)$, $\gamma Z$, and $ZZ$. Consequently, it is found that the strongest limit for this spin-2 resonance $G$ comes from the $t\bar{t}$ pair search, which constrains the cutoff scale to be of ${\cal O}$(100 GeV) for the right-top coupling of ${\cal O}(1)$ and the massive graviton mass in the range $m_G$=2-5 TeV, significantly relaxed compared with the universal $G$ coupling case.
[ { "created": "Wed, 25 Jul 2018 14:47:17 GMT", "version": "v1" }, { "created": "Thu, 4 Oct 2018 12:24:46 GMT", "version": "v2" } ]
2018-10-12
[ [ "Geng", "Chao-Qiang", "" ], [ "Huang", "Da", "" ], [ "Yamashita", "Kimiko", "" ] ]
We study the phenomenology of a massive graviton $G$ with non-universal couplings to the Standard Model (SM) particles. Such a particle can arise as a warped Kaluza-Klein graviton from a framework of the Randall-Sundrum extra-dimension model. In particular, we consider a case in which $G$ is top-philic, i.e., $G$ interacts strongly with the right-handed top quark, resulting in the large top-loop contributions to its production via the gluon fusion and its decays to the SM gauge bosons. We take into account the constraints from the current 13 TeV LHC data on the channels of $t\bar{t}$, $\gamma\gamma$, $jj (gg)$, $\gamma Z$, and $ZZ$. Consequently, it is found that the strongest limit for this spin-2 resonance $G$ comes from the $t\bar{t}$ pair search, which constrains the cutoff scale to be of ${\cal O}$(100 GeV) for the right-top coupling of ${\cal O}(1)$ and the massive graviton mass in the range $m_G$=2-5 TeV, significantly relaxed compared with the universal $G$ coupling case.
1706.03666
Jussi Auvinen
Jussi Auvinen, Iurii Karpenko, Jonah E. Bernhard and Steffen A. Bass
Investigating the collision energy dependence of $\eta$/s in RHIC beam energy scan using Bayesian statistics
44 pages, 34 figures. Submitted to Phys. Rev. C
Phys. Rev. C 97, 044905 (2018)
10.1103/PhysRevC.97.044905
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the probability distributions of shear viscosity over the entropy density ratio $\eta/s$ in Au+Au collisions at $\sqrt{s_{NN}}=19.6, 39$, and $62.4$ GeV, using Bayesian inference and Gaussian process emulators for a model-to-data statistical analysis that probes the full input parameter space of a transport+viscous hydrodynamics hybrid model. We find the most likely value of $\eta/s$ to be larger at smaller $\sqrt{s_{NN}}$, although the uncertainties still allow for a constant value between 0.10 and 0.15 for the investigated collision energy range.
[ { "created": "Mon, 12 Jun 2017 14:45:24 GMT", "version": "v1" } ]
2018-04-18
[ [ "Auvinen", "Jussi", "" ], [ "Karpenko", "Iurii", "" ], [ "Bernhard", "Jonah E.", "" ], [ "Bass", "Steffen A.", "" ] ]
We determine the probability distributions of shear viscosity over the entropy density ratio $\eta/s$ in Au+Au collisions at $\sqrt{s_{NN}}=19.6, 39$, and $62.4$ GeV, using Bayesian inference and Gaussian process emulators for a model-to-data statistical analysis that probes the full input parameter space of a transport+viscous hydrodynamics hybrid model. We find the most likely value of $\eta/s$ to be larger at smaller $\sqrt{s_{NN}}$, although the uncertainties still allow for a constant value between 0.10 and 0.15 for the investigated collision energy range.
2008.10128
Jo\~ao Barata
Jo\~ao Barata, Fabio Dominguez, Carlos Salgado, Victor Vila
Simple implementation of color coherence for the resumation of soft BDMPS-Z gluons
5 pages, 1 figure; 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The evolution of QCD jets under the influence of a dense colored medium leads to the non trivial modification of the gluon emission spectrum. In the multiple soft scattering regime, for sufficiently large media, soft and wide angle emissions can be resummed (in the planar limit of QCD) due to the small formation time of each gluon emission. Similarly to DGLAP evolution, such cascades correspond to pure Markovian processes and interferences between partons are neglected. In this strict limit, color coherence effects are absent. In the vacuum this coherence effect is critical to guarantee that the shower is angular ordered. In the medium, it is known that such color coherence effects might play a role in suppressing radiation at intermediate emission angles. We present a simple procedure to implement color (de)coherence effects into the in-medium evolution equations obtained in the pure Markovian approximation. We verify that the result obtained is in accordance with previous studies regarding the role of in-medium color coherence in the evolution of the QCD antenna. The new evolution equation incorporates a novel emission kernel which enforces color coherence between emitters.
[ { "created": "Sun, 23 Aug 2020 23:14:10 GMT", "version": "v1" } ]
2020-08-25
[ [ "Barata", "João", "" ], [ "Dominguez", "Fabio", "" ], [ "Salgado", "Carlos", "" ], [ "Vila", "Victor", "" ] ]
The evolution of QCD jets under the influence of a dense colored medium leads to the non trivial modification of the gluon emission spectrum. In the multiple soft scattering regime, for sufficiently large media, soft and wide angle emissions can be resummed (in the planar limit of QCD) due to the small formation time of each gluon emission. Similarly to DGLAP evolution, such cascades correspond to pure Markovian processes and interferences between partons are neglected. In this strict limit, color coherence effects are absent. In the vacuum this coherence effect is critical to guarantee that the shower is angular ordered. In the medium, it is known that such color coherence effects might play a role in suppressing radiation at intermediate emission angles. We present a simple procedure to implement color (de)coherence effects into the in-medium evolution equations obtained in the pure Markovian approximation. We verify that the result obtained is in accordance with previous studies regarding the role of in-medium color coherence in the evolution of the QCD antenna. The new evolution equation incorporates a novel emission kernel which enforces color coherence between emitters.
hep-ph/9809392
Ugo Aglietti UA
U. Aglietti (Rome I University)
Effective Theories for Exclusive and Seminclusive Processes and Factorization
LaTex file, 4 pages, no figures; talk given at the QCD 98 Euroconference 2-8th July 1998 Montpellier (France) to be published in Nucl. Phys. B (Proc. Suppl.)
Nucl.Phys.Proc.Suppl. 74 (1999) 268-271
10.1016/S0920-5632(99)00176-0
Rome I preprint, ROME1/1221(98)
hep-ph
null
The effective theories for massless quarks describing exclusive and seminclusive processes are discussed, considering in particular the factorization problem.
[ { "created": "Tue, 15 Sep 1998 10:32:19 GMT", "version": "v1" } ]
2009-10-31
[ [ "Aglietti", "U.", "", "Rome I University" ] ]
The effective theories for massless quarks describing exclusive and seminclusive processes are discussed, considering in particular the factorization problem.
2008.13725
Oleksii Matsedonskyi
Oleksii Matsedonskyi
High-Temperature Electroweak Symmetry Breaking by SM Twins
8 pages, 4 figures; minor corrections, extended introductory part
null
10.1007/JHEP04(2021)036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse a possible adjustment of Twin Higgs models allowing to have broken electroweak (EW) symmetry at all temperatures below the sigma-model scale $\sim 1$TeV. The modification consists of increasing the Yukawa couplings of the twins of light SM fermions. The naturalness considerations then imply a presence of relatively light electroweak-charged fermions, which can be produced at the LHC, and decay into SM gauge and Higgs bosons and missing energy. Analysis of experimental bounds shows that such a modified model features an increased amount of fine-tuning compared to the original Twin Higgs models, but still less tuning than the usual pseudo-Nambu-Goldstone Higgs models not improved by $Z_2$ symmetry. The obtained modification in the evolution of the EW symmetry breaking strength can, in particular, have interesting implications for models of EW baryogenesis, which we comment on.
[ { "created": "Mon, 31 Aug 2020 16:44:23 GMT", "version": "v1" }, { "created": "Wed, 17 Mar 2021 12:22:11 GMT", "version": "v2" } ]
2021-04-21
[ [ "Matsedonskyi", "Oleksii", "" ] ]
We analyse a possible adjustment of Twin Higgs models allowing to have broken electroweak (EW) symmetry at all temperatures below the sigma-model scale $\sim 1$TeV. The modification consists of increasing the Yukawa couplings of the twins of light SM fermions. The naturalness considerations then imply a presence of relatively light electroweak-charged fermions, which can be produced at the LHC, and decay into SM gauge and Higgs bosons and missing energy. Analysis of experimental bounds shows that such a modified model features an increased amount of fine-tuning compared to the original Twin Higgs models, but still less tuning than the usual pseudo-Nambu-Goldstone Higgs models not improved by $Z_2$ symmetry. The obtained modification in the evolution of the EW symmetry breaking strength can, in particular, have interesting implications for models of EW baryogenesis, which we comment on.
hep-ph/9904392
Mahbub Majumdar
A.C. Davis (DAMTP), M. Majumdar (DAMTP)
Inflation in Supersymmetric Cosmic String Theories
5 pages
Phys.Lett. B460 (1999) 257-262
10.1016/S0370-2693(99)00801-1
DAMTP 1999-37
hep-ph
null
We examine a non-Abelian SUSY $SU(2) \times U(1)$ gauge theory and a SUSY U(1) theory originally used to investigate the microphysics of cosmic strings in supersymmetric theories. We show that both theories automatically include hybrid inflation. In the latter theory we use a $D$ term to break the symmetry. SUSY is broken during inflation and restored afterwards. Cosmic strings are formed at the end of inflation. The temperature anisotropy is calculated and found to vary as $(M_{GUT}/M_P)^2$.
[ { "created": "Mon, 19 Apr 1999 15:30:45 GMT", "version": "v1" } ]
2009-10-31
[ [ "Davis", "A. C.", "", "DAMTP" ], [ "Majumdar", "M.", "", "DAMTP" ] ]
We examine a non-Abelian SUSY $SU(2) \times U(1)$ gauge theory and a SUSY U(1) theory originally used to investigate the microphysics of cosmic strings in supersymmetric theories. We show that both theories automatically include hybrid inflation. In the latter theory we use a $D$ term to break the symmetry. SUSY is broken during inflation and restored afterwards. Cosmic strings are formed at the end of inflation. The temperature anisotropy is calculated and found to vary as $(M_{GUT}/M_P)^2$.
1210.7939
Arsen Yeghiazaryan
H. M. Asatrian, A. Hovhannisyan, A. Yeghiazaryan
Phase space analysis for three and four massive particles in final states
8 pages, 1 figure
Phys. Rev. D 86, 114023 (2012)
10.1103/PhysRevD.86.114023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose formulae for computing the phase space integrals of $1\to 3$ and $1\to 4$ processes with massive particles in final states. As an application of these formulae we study the final state mass effects in some interesting phenomenological cases, giving fully integrated analytic results for the corresponding phase spaces. We consider also the $B_s-\bar{B}_s$ process at NNLO and calculate one of the most complicated master integrals, which contributes to the $\Delta\Gamma_{B_s}$ at $O(\alpha_s^2)$.
[ { "created": "Tue, 30 Oct 2012 09:28:24 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2012 13:39:28 GMT", "version": "v2" }, { "created": "Mon, 12 Nov 2012 10:08:08 GMT", "version": "v3" }, { "created": "Fri, 21 Dec 2012 10:36:24 GMT", "version": "v4" } ]
2012-12-24
[ [ "Asatrian", "H. M.", "" ], [ "Hovhannisyan", "A.", "" ], [ "Yeghiazaryan", "A.", "" ] ]
We propose formulae for computing the phase space integrals of $1\to 3$ and $1\to 4$ processes with massive particles in final states. As an application of these formulae we study the final state mass effects in some interesting phenomenological cases, giving fully integrated analytic results for the corresponding phase spaces. We consider also the $B_s-\bar{B}_s$ process at NNLO and calculate one of the most complicated master integrals, which contributes to the $\Delta\Gamma_{B_s}$ at $O(\alpha_s^2)$.
1505.02013
Dipankar Chakrabarti
Dipankar Chakrabarti, Chandan Mondal, Asmita Mukherjee
Gravitational form factors and transverse spin sum rule in a light front quark-diquark model in AdS/QCD
28 pages, 7 figures
Phys. Rev. D 91, 114026 (2015)
10.1103/PhysRevD.91.114026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gravitational form factors are related to the matrix elements of the energy-momentum tensor $T^{\mu\nu}$. Using the light front wave functions of the scalar quark-diquark model for nucleon predicted by the soft-wall AdS/QCD, we calculate the flavor dependent $A(Q^2)$, $B(Q^2)$ and $\bar{C}(Q^2)$ form factors. We also present all the matrix element of the energy-momentum tensor in a transversely polarized state. Further, we evaluate the matrix element of Pauli-Lubanski operator in this model and show that the intrinsic spin sum rule involves the form factor $\bar{C}$. The longitudinal momentum densities in the transverse impact parameter space are also discussed for both unpolarized and transversely polarized nucleons.
[ { "created": "Fri, 8 May 2015 12:25:53 GMT", "version": "v1" } ]
2015-06-24
[ [ "Chakrabarti", "Dipankar", "" ], [ "Mondal", "Chandan", "" ], [ "Mukherjee", "Asmita", "" ] ]
The gravitational form factors are related to the matrix elements of the energy-momentum tensor $T^{\mu\nu}$. Using the light front wave functions of the scalar quark-diquark model for nucleon predicted by the soft-wall AdS/QCD, we calculate the flavor dependent $A(Q^2)$, $B(Q^2)$ and $\bar{C}(Q^2)$ form factors. We also present all the matrix element of the energy-momentum tensor in a transversely polarized state. Further, we evaluate the matrix element of Pauli-Lubanski operator in this model and show that the intrinsic spin sum rule involves the form factor $\bar{C}$. The longitudinal momentum densities in the transverse impact parameter space are also discussed for both unpolarized and transversely polarized nucleons.