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2104.14254
Piotr Korcyl
Salvatore Cali, Krzysztof Cichy, Piotr Korcyl, Piotr Kotko, Krzysztof Kutak, Cyrille Marquet
On systematic effects in the numerical solutions of the JIMWLK equation
21 pages, 18 figures, references updated
null
10.1140/epjc/s10052-021-09380-6
IFJPAN-IV-2021-7
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the high energy limit of hadron collisions, the evolution of the gluon density in the longitudinal momentum fraction can be deduced from the Balitsky hierarchy of equations or, equivalently, from the nonlinear Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner (JIMWLK) equation. The solutions of the latter can be studied numerically by using its reformulation in terms of a Langevin equation. In this paper, we present a comprehensive study of systematic effects associated with the numerical framework, in particular the ones related to the inclusion of the running coupling. We consider three proposed ways in which the running of the coupling constant can be included: "square root" and "noise" prescriptions and the recent proposal by Hatta and Iancu. We implement them both in position and momentum spaces and we investigate and quantify the differences in the resulting evolved gluon distributions. We find that the systematic differences associated with the implementation technicalities can be of a similar magnitude as differences in running coupling prescriptions in some cases, or much smaller in other cases.
[ { "created": "Thu, 29 Apr 2021 10:53:02 GMT", "version": "v1" }, { "created": "Thu, 6 May 2021 09:11:03 GMT", "version": "v2" } ]
2021-08-18
[ [ "Cali", "Salvatore", "" ], [ "Cichy", "Krzysztof", "" ], [ "Korcyl", "Piotr", "" ], [ "Kotko", "Piotr", "" ], [ "Kutak", "Krzysztof", "" ], [ "Marquet", "Cyrille", "" ] ]
In the high energy limit of hadron collisions, the evolution of the gluon density in the longitudinal momentum fraction can be deduced from the Balitsky hierarchy of equations or, equivalently, from the nonlinear Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner (JIMWLK) equation. The solutions of the latter can be studied numerically by using its reformulation in terms of a Langevin equation. In this paper, we present a comprehensive study of systematic effects associated with the numerical framework, in particular the ones related to the inclusion of the running coupling. We consider three proposed ways in which the running of the coupling constant can be included: "square root" and "noise" prescriptions and the recent proposal by Hatta and Iancu. We implement them both in position and momentum spaces and we investigate and quantify the differences in the resulting evolved gluon distributions. We find that the systematic differences associated with the implementation technicalities can be of a similar magnitude as differences in running coupling prescriptions in some cases, or much smaller in other cases.
2007.08067
Naoki Yamatsu
Naoki Yamatsu
$USp(32)$ Special Grand Unification
16 pages, 3 tables, no figures
null
null
KYUSHU-HET-215
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a grand unified theory (GUT) based on a $USp(32)$ GUT gauge group broken to its subgroups including a special subgroup. A GUT based on an $SO(32)$ GUT gauge group has been discussed on six-dimensional (6D) orbifold space $M^4\times T^2/\mathbb{Z}_2$. It is inspired by the $SO(32)$ string theory behind the $SU(16)$ GUT whose $SU(16)$ is broken to a special subgroup $SO(10)$. Alternative direction is to embed an $SU(16)$ gauge group into a $USp(32)$ GUT gauge group, which is inspired by a non-supersymmetric symplectic-type $USp(32)$ string theory. In a $USp(32)$ GUT, one generation of the SM fermions is embedded into a 6D bulk Weyl fermion in a $USp(32)$ defining representation. For a three generation model, all the 6D and 4D gauge anomalies in the bulk and on the fixed points are canceled out without exotic chiral fermions at low energies. The SM Higgs scalar is embedded into a 6D bulk scalar field in a $USp(32)$ adjoint representation.
[ { "created": "Thu, 16 Jul 2020 01:40:34 GMT", "version": "v1" } ]
2020-07-17
[ [ "Yamatsu", "Naoki", "" ] ]
We discuss a grand unified theory (GUT) based on a $USp(32)$ GUT gauge group broken to its subgroups including a special subgroup. A GUT based on an $SO(32)$ GUT gauge group has been discussed on six-dimensional (6D) orbifold space $M^4\times T^2/\mathbb{Z}_2$. It is inspired by the $SO(32)$ string theory behind the $SU(16)$ GUT whose $SU(16)$ is broken to a special subgroup $SO(10)$. Alternative direction is to embed an $SU(16)$ gauge group into a $USp(32)$ GUT gauge group, which is inspired by a non-supersymmetric symplectic-type $USp(32)$ string theory. In a $USp(32)$ GUT, one generation of the SM fermions is embedded into a 6D bulk Weyl fermion in a $USp(32)$ defining representation. For a three generation model, all the 6D and 4D gauge anomalies in the bulk and on the fixed points are canceled out without exotic chiral fermions at low energies. The SM Higgs scalar is embedded into a 6D bulk scalar field in a $USp(32)$ adjoint representation.
hep-ph/9711469
Philippe Ruelle
J.-M. Gerard and J. Weyers
Isospin amplitudes and CP violation in $(B \to K\pi)$ decays
6 pages, no figure
Eur.Phys.J.C7:1-3,1999
10.1007/s100529800980
UCL-IPT-97-18
hep-ph
null
We present a simple isospin invariant parametrization for $(B \to K\pi)$ decay amplitudes which consistently includes CP violation and (quasi-elastic) hadronic final states interactions. We find that the observed $(B \to K\pi)$ decays do not lead to a significant bound on the angle $\gamma$ of the unitarity triangle. On the other hand, we claim that a sizeable CP violation asymmetry in $(B^{\pm} \to K\pi^{\pm})$ rates is by no means excluded.
[ { "created": "Tue, 25 Nov 1997 14:27:46 GMT", "version": "v1" } ]
2010-11-23
[ [ "Gerard", "J. -M.", "" ], [ "Weyers", "J.", "" ] ]
We present a simple isospin invariant parametrization for $(B \to K\pi)$ decay amplitudes which consistently includes CP violation and (quasi-elastic) hadronic final states interactions. We find that the observed $(B \to K\pi)$ decays do not lead to a significant bound on the angle $\gamma$ of the unitarity triangle. On the other hand, we claim that a sizeable CP violation asymmetry in $(B^{\pm} \to K\pi^{\pm})$ rates is by no means excluded.
hep-ph/9504205
Joakim Edsjo
J. Edsjo (Uppsala University)
Neutrino-induced Muon Fluxes from Neutralino Annihilations in the Sun and in the Earth
4 pages, 2 figures (uuencoded compressed tar-files), uses espcrc2.sty
Nucl.Phys.Proc.Suppl.43:265-268,1995
10.1016/0920-5632(95)00487-T
null
hep-ph
null
The flux of neutrino-induced muons at the surface of the Earth is calculated from injection of neutralino annihilation products in the core of the Sun and the Earth. An improved treatment of neutrino propagation through the Sun is performed and the results are presented in an easy-to-use parameterization. For an explicit supersymmetric model, an observable neutralino annihilation signal is demonstrated.
[ { "created": "Mon, 3 Apr 1995 15:44:40 GMT", "version": "v1" } ]
2010-11-01
[ [ "Edsjo", "J.", "", "Uppsala University" ] ]
The flux of neutrino-induced muons at the surface of the Earth is calculated from injection of neutralino annihilation products in the core of the Sun and the Earth. An improved treatment of neutrino propagation through the Sun is performed and the results are presented in an easy-to-use parameterization. For an explicit supersymmetric model, an observable neutralino annihilation signal is demonstrated.
hep-ph/9912260
Gi-Chol Cho
Gi-Chol Cho (Scuola Normale Superiore and KEK), Kaoru Hagiwara (KEK)
Supersymmetry versus precision experiments revisited
61 pages, 16 figures. References added. version to appear in Nuclear Physics B
Nucl.Phys.B574:623-674,2000
10.1016/S0550-3213(00)00027-4
KEK-TH-648, SNS-PH-99-16
hep-ph
null
We study constraints on the supersymmetric standard model from the updated electroweak precision measurements --- the Z-pole experiments and the $W$-boson mass measurements. The supersymmetric-particle contributions to the universal gauge-boson-propagator corrections are parametrized by the three oblique parameters Sz, Tz and mw. The oblique corrections, the Zqq and Zll vertex corrections, and the vertex and box corrections to the \mu-decay width are separately studied in detail. We first study individual contribution from the four sectors of the model, the squarks, the sleptons, the supersymmetric fermions (charginos and neutralinos), and the supersymmetric Higgs bosons, to the universal oblique parameters, where the sum of individual contributions gives the total correction. We find that the light squarks or sleptons, whose masses just above the present direct search limits, always make the fit worse than that of the Standard Model (SM), whereas the light charginos and neutralinos generally make the fit slightly better. The contribution from the supersymmetric Higgs sector is found small. We then study the vertex/box corrections carefully when both the supersymmetric fermions (-inos) and the supersymmetric scalars (squarks and sleptons) are light, and find that no significant improvement over the SM fit is achieved. The best overall fit to the precision measurements are found when charginos of mass $\sim 100\gev$ with a dominant wino-component are present and the doublet squarks and sleptons are all much heavier. The improvement over the SM is marginal, however, where the total \chi^2 of the fit to the 22 data points decreases by about one unit, due mainly to a slightly better fit to the $Z$-boson total width.
[ { "created": "Tue, 7 Dec 1999 14:41:29 GMT", "version": "v1" }, { "created": "Tue, 18 Jan 2000 11:14:02 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cho", "Gi-Chol", "", "Scuola Normale Superiore and KEK" ], [ "Hagiwara", "Kaoru", "", "KEK" ] ]
We study constraints on the supersymmetric standard model from the updated electroweak precision measurements --- the Z-pole experiments and the $W$-boson mass measurements. The supersymmetric-particle contributions to the universal gauge-boson-propagator corrections are parametrized by the three oblique parameters Sz, Tz and mw. The oblique corrections, the Zqq and Zll vertex corrections, and the vertex and box corrections to the \mu-decay width are separately studied in detail. We first study individual contribution from the four sectors of the model, the squarks, the sleptons, the supersymmetric fermions (charginos and neutralinos), and the supersymmetric Higgs bosons, to the universal oblique parameters, where the sum of individual contributions gives the total correction. We find that the light squarks or sleptons, whose masses just above the present direct search limits, always make the fit worse than that of the Standard Model (SM), whereas the light charginos and neutralinos generally make the fit slightly better. The contribution from the supersymmetric Higgs sector is found small. We then study the vertex/box corrections carefully when both the supersymmetric fermions (-inos) and the supersymmetric scalars (squarks and sleptons) are light, and find that no significant improvement over the SM fit is achieved. The best overall fit to the precision measurements are found when charginos of mass $\sim 100\gev$ with a dominant wino-component are present and the doublet squarks and sleptons are all much heavier. The improvement over the SM is marginal, however, where the total \chi^2 of the fit to the 22 data points decreases by about one unit, due mainly to a slightly better fit to the $Z$-boson total width.
hep-ph/0204257
Subhendra Mohanty
Subhendra Mohanty, B.Mukhopadhyay and A.R.Prasanna
Baryogenesis from primordial tensor perturbations
9 pages Latex file
null
null
null
hep-ph astro-ph
null
During inflation primordial quantum fluctuations of the spacetime metric become classical and there is a spontaneous CPT violation by the spin connection coupling terms of the metric with fermions. The energy levels of the left and the right chirality neutrinos is split which gives rise to a net lepton asymmetry at equilibrium. A net baryon asymmetry of the same magnitude can be generated from this lepton asymmetry either by a GUT, $B-L$ symmetry or by electroweak sphaleron processes which preserve $B+L$ symmetry. If the amplitude of the primordial tensor perturbations is of the order of $10^{-6}$ (as is expected from inflation models) and the lepton/baryon number violating processes freeze out at the GUT era $T_d \sim 10^{16} Gev$ then a baryon number asymmetry of the correct magnitude $10^{-10}$ can be generated.
[ { "created": "Mon, 22 Apr 2002 12:16:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mohanty", "Subhendra", "" ], [ "Mukhopadhyay", "B.", "" ], [ "Prasanna", "A. R.", "" ] ]
During inflation primordial quantum fluctuations of the spacetime metric become classical and there is a spontaneous CPT violation by the spin connection coupling terms of the metric with fermions. The energy levels of the left and the right chirality neutrinos is split which gives rise to a net lepton asymmetry at equilibrium. A net baryon asymmetry of the same magnitude can be generated from this lepton asymmetry either by a GUT, $B-L$ symmetry or by electroweak sphaleron processes which preserve $B+L$ symmetry. If the amplitude of the primordial tensor perturbations is of the order of $10^{-6}$ (as is expected from inflation models) and the lepton/baryon number violating processes freeze out at the GUT era $T_d \sim 10^{16} Gev$ then a baryon number asymmetry of the correct magnitude $10^{-10}$ can be generated.
hep-ph/9602211
Ricardo Flores, UofMissouri-St. Louis
John Ellis (TH, CERN), Ricardo A. Flores (UM-St. Louis)
Implications of the Strange Spin of the Nucleon for the Neutron Electric Dipole Moment in Supersymmetric Theories
11 pages, uuencoded compressed postscript file including text and 3 figures
Phys.Lett.B377:83-88,1996
10.1016/0370-2693(96)00312-7
CERN-TH/96-18
hep-ph
null
Supersymmetric model contributions to the neutron electric dipole moment arise via quark electric dipole moment operators, whose matrix elements are usually calculated using the Naive Quark Model (NQM). However, experiments indicate that the NQM does not describe well the quark contributions $\Delta q$ to the nucleon spin, and so may provide misleading estimates of electric dipole operator matrix elements. Taking the $\Delta q$ from experiment, we indeed find consistently smaller estimates of the neutron electric dipole moment for given values of the supersymmetric model parameters. This weakens previous constraints on CP violation in supersymmetric models, which we exemplify analytically in the case where the lightest supersymmetric particle (LSP) is a $U(1)$ gaugino $\tilde{B}$, and display numerically for other LSP candidates.
[ { "created": "Fri, 2 Feb 1996 02:38:26 GMT", "version": "v1" } ]
2009-09-11
[ [ "Ellis", "John", "", "TH, CERN" ], [ "Flores", "Ricardo A.", "", "UM-St. Louis" ] ]
Supersymmetric model contributions to the neutron electric dipole moment arise via quark electric dipole moment operators, whose matrix elements are usually calculated using the Naive Quark Model (NQM). However, experiments indicate that the NQM does not describe well the quark contributions $\Delta q$ to the nucleon spin, and so may provide misleading estimates of electric dipole operator matrix elements. Taking the $\Delta q$ from experiment, we indeed find consistently smaller estimates of the neutron electric dipole moment for given values of the supersymmetric model parameters. This weakens previous constraints on CP violation in supersymmetric models, which we exemplify analytically in the case where the lightest supersymmetric particle (LSP) is a $U(1)$ gaugino $\tilde{B}$, and display numerically for other LSP candidates.
0912.0937
Anson Hook
Anson Hook and Jay G. Wacker
Collective Quartics from Simple Groups
22 pages, 2 figures
JHEP 1006:041,2010
10.1007/JHEP06(2010)041
SLAC-PUB-13865
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article classifies Little Higgs models that have collective quartic couplings. There are two classes of collective quartics: Special Cosets and Special Quartics. After taking into account dangerous singlets, the smallest Special Coset models are SU(5)/SO(5) and SU(6)/Sp(6). The smallest Special Quartic model is SU(5)/SU(3) x SU(2) x U(1) and has not previously been considered as a candidate Little Higgs model.
[ { "created": "Mon, 7 Dec 2009 15:17:53 GMT", "version": "v1" }, { "created": "Sat, 10 Apr 2010 02:53:44 GMT", "version": "v2" } ]
2014-11-20
[ [ "Hook", "Anson", "" ], [ "Wacker", "Jay G.", "" ] ]
This article classifies Little Higgs models that have collective quartic couplings. There are two classes of collective quartics: Special Cosets and Special Quartics. After taking into account dangerous singlets, the smallest Special Coset models are SU(5)/SO(5) and SU(6)/Sp(6). The smallest Special Quartic model is SU(5)/SU(3) x SU(2) x U(1) and has not previously been considered as a candidate Little Higgs model.
hep-ph/9502406
null
E.A. Kuraev, Z.K. Silagadze
Once more about the $\omega \to 3\pi$ contact term
13 pages, LaTex, without some figures. To appear in Yad. Fiz.
Phys.Atom.Nucl.58:1589-1596,1995; Yad.Fiz.58N9:1687-1694,1995
null
BUDKERINP 93-52 (Novosibirsk)
hep-ph
null
The manifestations of the $\omega \to 3\pi$ contact term and its unitary partners are investigated in the framework of the chiral effective lagrangian theory with vector mesons. We conclude that nowadays the existence and magnitude of the contact term can be extracted neither from theory, nor experiment. The theoretical uncertainty is caused by the one-loop corrections. Some speculations about them lead to the generalized KSRF relation $\frac{f_\pi^2g^2_{\rho \pi \pi}}{m_\rho^2}=\frac{m_K}{2\sqrt{2} \pi f_\pi}$.
[ { "created": "Tue, 28 Feb 1995 13:11:56 GMT", "version": "v1" } ]
2019-08-15
[ [ "Kuraev", "E. A.", "" ], [ "Silagadze", "Z. K.", "" ] ]
The manifestations of the $\omega \to 3\pi$ contact term and its unitary partners are investigated in the framework of the chiral effective lagrangian theory with vector mesons. We conclude that nowadays the existence and magnitude of the contact term can be extracted neither from theory, nor experiment. The theoretical uncertainty is caused by the one-loop corrections. Some speculations about them lead to the generalized KSRF relation $\frac{f_\pi^2g^2_{\rho \pi \pi}}{m_\rho^2}=\frac{m_K}{2\sqrt{2} \pi f_\pi}$.
1204.6038
Prashant Saraswat
Peter W. Graham, David E. Kaplan, Surjeet Rajendran, Prashant Saraswat
Displaced Supersymmetry
35 pages, 4 figures
JHEP 1207 (2012) 149
10.1007/JHEP07(2012)149
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The apparent absence of light superpartners at the LHC strongly constrains the viability of the MSSM as a solution to the hierarchy problem. These constraints can be significantly alleviated by R-parity violation (RPV). Bilinear R-parity violation, with the single operator L H_u, does not require any special flavor structure and can be naturally embedded in a GUT while avoiding constraints from proton decay (unlike baryon-number-violating RPV). The LSP in this scenario can be naturally long-lived, giving rise to displaced vertices. Many collider searches, particularly those selecting b-jets or leptons, are insensitive to events with such detector-scale displaced decays owing to cuts on track quality and impact parameter. We demonstrate that for decay lengths in the window ~1-1000 mm, constraints on superpartner masses can be as low as ~450 GeV for squarks and ~40 GeV for LSPs. In some parts of parameter space light LSPs can dominate the Higgs decay width, hiding the Higgs from existing searches. This framework motivates collider searches for detector-scale displaced vertices. LHCb may be ideally suited to trigger on such events, while ATLAS and CMS may need to trigger on missing energy in the event.
[ { "created": "Thu, 26 Apr 2012 20:00:00 GMT", "version": "v1" } ]
2012-10-02
[ [ "Graham", "Peter W.", "" ], [ "Kaplan", "David E.", "" ], [ "Rajendran", "Surjeet", "" ], [ "Saraswat", "Prashant", "" ] ]
The apparent absence of light superpartners at the LHC strongly constrains the viability of the MSSM as a solution to the hierarchy problem. These constraints can be significantly alleviated by R-parity violation (RPV). Bilinear R-parity violation, with the single operator L H_u, does not require any special flavor structure and can be naturally embedded in a GUT while avoiding constraints from proton decay (unlike baryon-number-violating RPV). The LSP in this scenario can be naturally long-lived, giving rise to displaced vertices. Many collider searches, particularly those selecting b-jets or leptons, are insensitive to events with such detector-scale displaced decays owing to cuts on track quality and impact parameter. We demonstrate that for decay lengths in the window ~1-1000 mm, constraints on superpartner masses can be as low as ~450 GeV for squarks and ~40 GeV for LSPs. In some parts of parameter space light LSPs can dominate the Higgs decay width, hiding the Higgs from existing searches. This framework motivates collider searches for detector-scale displaced vertices. LHCb may be ideally suited to trigger on such events, while ATLAS and CMS may need to trigger on missing energy in the event.
2308.10314
Rafiqul Rahaman
Tathagata Ghosh, Rafiqul Rahaman, and Santosh Kumar Rai
Search for a leptophobic doubly charged Higgs in same-sign four-lepton and six-lepton signatures in a left-right symmetric model
32 pages, 8 figures, and 4 tables
null
null
HRI-RECAPP-2023-04
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We investigate the possibility of multi-lepton (four and six) signatures, including an exotic signature of same-sign four-lepton (SS4L) as signals of pair production of a doubly charged Higgs in the minimal left-right symmetric model, extended with two doublet scalars. The right-handed neutrino masses are generated in this model through a dimension-$5$ lepton-number violating operator allowing the triplet scalar interactions with leptons to become negligibly small. This leads to interesting six-lepton and SS4L signatures that can be observed at the high-luminosity phase of the Large Hadron Collider (HL-LHC) with almost no background for doubly charged Higgs with mass below 500 GeV.
[ { "created": "Sun, 20 Aug 2023 16:24:50 GMT", "version": "v1" } ]
2023-08-22
[ [ "Ghosh", "Tathagata", "" ], [ "Rahaman", "Rafiqul", "" ], [ "Rai", "Santosh Kumar", "" ] ]
We investigate the possibility of multi-lepton (four and six) signatures, including an exotic signature of same-sign four-lepton (SS4L) as signals of pair production of a doubly charged Higgs in the minimal left-right symmetric model, extended with two doublet scalars. The right-handed neutrino masses are generated in this model through a dimension-$5$ lepton-number violating operator allowing the triplet scalar interactions with leptons to become negligibly small. This leads to interesting six-lepton and SS4L signatures that can be observed at the high-luminosity phase of the Large Hadron Collider (HL-LHC) with almost no background for doubly charged Higgs with mass below 500 GeV.
1507.03470
Rob Verheyen
Wim Beenakker, Tom van Daal, Ronald Kleiss, Rob Verheyen
Renormalization group invariants in supersymmetric theories: one- and two-loop results
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We stress the potential usefulness of renormalization group invariants. Especially particular combinations thereof could for instance be used as probes into patterns of supersymmetry breaking in the MSSM at inaccessibly high energies. We search for these renormalization group invariants in two systematic ways: on the one hand by making use of symmetry arguments and on the other by means of a completely automated exhaustive search through a large class of candidate invariants. At the one-loop level, we find all known invariants for the MSSM and in fact several more, and extend our results to the more constrained pMSSM and dMSSM, leading to even more invariants. Extending our search to the two-loop level we find that the number of invariants is considerably reduced.
[ { "created": "Mon, 13 Jul 2015 14:24:42 GMT", "version": "v1" }, { "created": "Thu, 10 Sep 2015 07:32:46 GMT", "version": "v2" } ]
2015-09-11
[ [ "Beenakker", "Wim", "" ], [ "van Daal", "Tom", "" ], [ "Kleiss", "Ronald", "" ], [ "Verheyen", "Rob", "" ] ]
We stress the potential usefulness of renormalization group invariants. Especially particular combinations thereof could for instance be used as probes into patterns of supersymmetry breaking in the MSSM at inaccessibly high energies. We search for these renormalization group invariants in two systematic ways: on the one hand by making use of symmetry arguments and on the other by means of a completely automated exhaustive search through a large class of candidate invariants. At the one-loop level, we find all known invariants for the MSSM and in fact several more, and extend our results to the more constrained pMSSM and dMSSM, leading to even more invariants. Extending our search to the two-loop level we find that the number of invariants is considerably reduced.
hep-ph/9810402
Joao M. Soares
Joao M. Soares
Form factor relations for pseudoscalar to vector meson transitions
Latex, 9 pages, submitted to Phys. Rev. D (May 1998)
null
null
null
hep-ph
null
In semi-leptonic and other weak decays of mesons, the hadronic matrix elements of the operators in the weak Hamiltonian are parametrized by standard sets of independent, Lorentz invariant, form factors. For the case of pseudoscalar to vector meson transitions, it has been shown that a Quark Model description leads to relations between some of the form factors. Here, I give an alternate, and more general, proof of those relations and thus confirm that, in the Quark Model, not all the form factors for pseudoscalar to vector meson transitions are independent. As an application of this result, a Quark Model measurement of the CKM parameter |Vub| can be obtained, where the dependence on all hadronic form factors is eliminated.
[ { "created": "Mon, 19 Oct 1998 13:50:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "Soares", "Joao M.", "" ] ]
In semi-leptonic and other weak decays of mesons, the hadronic matrix elements of the operators in the weak Hamiltonian are parametrized by standard sets of independent, Lorentz invariant, form factors. For the case of pseudoscalar to vector meson transitions, it has been shown that a Quark Model description leads to relations between some of the form factors. Here, I give an alternate, and more general, proof of those relations and thus confirm that, in the Quark Model, not all the form factors for pseudoscalar to vector meson transitions are independent. As an application of this result, a Quark Model measurement of the CKM parameter |Vub| can be obtained, where the dependence on all hadronic form factors is eliminated.
hep-ph/9712226
Georg Weiglein
G. Weiglein
QCD Corrections to Electroweak Precision Observables in SUSY Theories
5 pages, LaTeX, 1 Postscript figure; to appear in the proceedings of the International Europhysics Conference on High-Energy Physics, Jerusalem, Israel, August 19-26, 1997; the paper is also available via www at http://www-itp.physik.uni-karlsruhe.de/prep/prep97/preplist97.html
null
null
KA-TP-25-1997
hep-ph
null
The two-loop QCD corrections to the $\rho$ parameter are derived in the Minimal Supersymmetric Standard Model. They turn out to be sizable and modify the one-loop result by up to 30%. Furthermore exact results for the gluonic corrections to $\Delta r$ are presented and compared with the leading contribution entering via the $\rho$ parameter.
[ { "created": "Tue, 2 Dec 1997 01:53:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Weiglein", "G.", "" ] ]
The two-loop QCD corrections to the $\rho$ parameter are derived in the Minimal Supersymmetric Standard Model. They turn out to be sizable and modify the one-loop result by up to 30%. Furthermore exact results for the gluonic corrections to $\Delta r$ are presented and compared with the leading contribution entering via the $\rho$ parameter.
1203.3648
Amand Faessler
Amand Faessler
The Neutrinoless Double Beta Decay, Physics beyond the Standard Model and the Neutrino Mass
13 pages, 5 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Neutrinoless double beta Decay allows to determine the effectice Majorana electron neutrino mass. For this the following conditions have to be satisfied: (i) The neutrino must be a Majorana particle, i. e. identical to the antiparticle. (ii) The half life has to be measured. (iii)The transition matrix element must be reliably calculated. (iv) The leading mechanism must be the light Majorana neutrino exchange. The present contribution studies the accuracy with which one can calculate by different methods: (1) Quasi-Particle Random Phase Approach (QRPA), (2) the Shell Model (SM), (3) the (before the variation) angular momentum projected Hartree-Fock-Bogoliubov method (PHFB)and the (4) Interacting Boson Approach (IBA). In the second part we investigate how to determine experimentally the leading mechanism for the Neutrinoless Double Beta Decay. Is it (a) the light Majorana neutrino exchange as one assumes to determine the effective Majorana neutrino mass, ist it the heavy left (b) or right handed (c) Majorana neutrino exchange allowed by left-right symmetric Grand Unified Theories (GUT's). Is it a mechanism due to Supersymmetry e.g. with gluino exchange and R-parity and lepton number violating terms. At the end we assume, that Klapdor et al. have indeed measured the Neutrinoless Double Beta Decay(, although contested,)and that the light Majorana neutrino exchange is the leading mechanism. With our matrix elements we obtain then an effective Majorana neutrino mass of: <m(nu)> = 0.24 [eV], exp (pm) 0.02; theor. (pm) 0.01 [eV]
[ { "created": "Fri, 16 Mar 2012 09:44:57 GMT", "version": "v1" } ]
2012-03-19
[ [ "Faessler", "Amand", "" ] ]
The Neutrinoless double beta Decay allows to determine the effectice Majorana electron neutrino mass. For this the following conditions have to be satisfied: (i) The neutrino must be a Majorana particle, i. e. identical to the antiparticle. (ii) The half life has to be measured. (iii)The transition matrix element must be reliably calculated. (iv) The leading mechanism must be the light Majorana neutrino exchange. The present contribution studies the accuracy with which one can calculate by different methods: (1) Quasi-Particle Random Phase Approach (QRPA), (2) the Shell Model (SM), (3) the (before the variation) angular momentum projected Hartree-Fock-Bogoliubov method (PHFB)and the (4) Interacting Boson Approach (IBA). In the second part we investigate how to determine experimentally the leading mechanism for the Neutrinoless Double Beta Decay. Is it (a) the light Majorana neutrino exchange as one assumes to determine the effective Majorana neutrino mass, ist it the heavy left (b) or right handed (c) Majorana neutrino exchange allowed by left-right symmetric Grand Unified Theories (GUT's). Is it a mechanism due to Supersymmetry e.g. with gluino exchange and R-parity and lepton number violating terms. At the end we assume, that Klapdor et al. have indeed measured the Neutrinoless Double Beta Decay(, although contested,)and that the light Majorana neutrino exchange is the leading mechanism. With our matrix elements we obtain then an effective Majorana neutrino mass of: <m(nu)> = 0.24 [eV], exp (pm) 0.02; theor. (pm) 0.01 [eV]
hep-ph/0505078
Krzysztof Turzynski
Krzysztof Turzynski
Decoupling, lepton flavour violation and leptogenesis
6 pages, 2 figures, talk given at the XXXXth Recontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Italy, 5-12 Mar 2005
null
null
IFT-05/11
hep-ph
null
Several classes of neutrino mass models, which can naturally account for hierarchical masses and the bi-large pattern of neutrino mixing, are constructed from a bottom-up perspective based on the idea of decoupling of one right-chiral neutrino from the seesaw mechanism. The interplay between the predictions for the lepton-flavour violation in the MSSM with universal soft masses and for leptogenesis is studied. In particular, classes of neutrino mass models in which successful leptogenesis implies BR(mu->e gamma) potentially observable in upcoming experiments are identified.
[ { "created": "Tue, 10 May 2005 16:27:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Turzynski", "Krzysztof", "" ] ]
Several classes of neutrino mass models, which can naturally account for hierarchical masses and the bi-large pattern of neutrino mixing, are constructed from a bottom-up perspective based on the idea of decoupling of one right-chiral neutrino from the seesaw mechanism. The interplay between the predictions for the lepton-flavour violation in the MSSM with universal soft masses and for leptogenesis is studied. In particular, classes of neutrino mass models in which successful leptogenesis implies BR(mu->e gamma) potentially observable in upcoming experiments are identified.
1509.06219
Mustafa Savci
T. M. Aliev, M. Savc{\i}
Magnetic moment for the negative parity $\Lambda \to \Sigma^0$ transition in light cone QCD sum rules
7 pages, no figures, LaTeX formatted
null
10.1016/j.physletb.2016.04.046
metu-phys-hep-09-20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The magnetic moment of the $\Lambda \to \Sigma^0$ transition between negative parity, baryons is calculated in framework of the QCD sum rules approach, using the general form of the interpolating currents. The pollution arising from the positive--to--positive, and positive to negative parity baryons are eliminated by constructing the sum rules for different Lorentz structures. Nonzero value of the considered magnetic moment can be attributed to the violation of the $SU(3)$ symmetry.
[ { "created": "Mon, 21 Sep 2015 13:25:55 GMT", "version": "v1" } ]
2016-06-22
[ [ "Aliev", "T. M.", "" ], [ "Savcı", "M.", "" ] ]
The magnetic moment of the $\Lambda \to \Sigma^0$ transition between negative parity, baryons is calculated in framework of the QCD sum rules approach, using the general form of the interpolating currents. The pollution arising from the positive--to--positive, and positive to negative parity baryons are eliminated by constructing the sum rules for different Lorentz structures. Nonzero value of the considered magnetic moment can be attributed to the violation of the $SU(3)$ symmetry.
hep-ph/9204217
Frank Hoogeveen
J. Bijnens, F. Hoogeveen
Two--Body Decays of $B_s$ Mesons
13p
Phys.Lett. B283 (1992) 434-438
10.1016/0370-2693(92)90044-5
null
hep-ph
null
We have calculated the decay rates of the $B_s$ meson in a number of exclusive two--body decay channels using the Bauer--Stech--Wirbel model for current matrix elements. The influence of the free parameters of the model on the predictions is studied. The total branching ratio of the $B_s$ into final states which only contain stable charged particles is found to be about $10^{-3}$.
[ { "created": "Mon, 13 Apr 1992 09:08:18 GMT", "version": "v1" } ]
2019-08-17
[ [ "Bijnens", "J.", "" ], [ "Hoogeveen", "F.", "" ] ]
We have calculated the decay rates of the $B_s$ meson in a number of exclusive two--body decay channels using the Bauer--Stech--Wirbel model for current matrix elements. The influence of the free parameters of the model on the predictions is studied. The total branching ratio of the $B_s$ into final states which only contain stable charged particles is found to be about $10^{-3}$.
2104.04328
Waqas Ahmed
Waqas Ahmed, Athanasios Karozas, George K. Leontaris
Gravitino Dark matter, Non Thermal Leptogenesis and Low reheating temperature in No-scale Higgs Inflation
31 pages, 20 figures
Phys. Rev. D 104, 055025 (2021)
10.1103/PhysRevD.104.055025
null
hep-ph gr-qc
http://creativecommons.org/licenses/by-nc-sa/4.0/
We revisit Higgs inflation in the framework of a minimal extension of the Standard Model gauge symmetry by a $U(1)_{B-L}$ factor. Various aspects are taken into account with particular focus on the role of the supersymmetry breaking (SUSY) scale and the cosmological constraints associated with the gravitino. The scalar potential of the model is considered in the context of no-scale supergravity consisting of the F-part constructed from the K\"ahler function, the D-terms and soft SUSY contributions. We investigate several limiting cases and by varying the SUSY scale from a few TeV up to intermediate energies, for a spectral index around $n_s\sim 0.9655$ and reheating temperature $T_r\le 10^{9}$ GeV we find that the value of the tensor-to-scalar ratio ranges from $r\approx 10^{-3}$ to $10^{-2}$. Furthermore, it is shown that for certain regions of the parameter space the gravitino can live sufficiently long and as such is a potential candidate for a dark matter component. In general, the inflationary scenario is naturally implemented and it is consistent with non-thermal leptogenesis whereas the dominant decay channel of the inflaton yields right-handed neutrinos. Other aspects of cosmology and particle physics phenomenology are briefly discussed. Finally, we investigate the case where the inflaton is initially relaxed in a false minimum and estimate its probability to decay to the true vacuum.
[ { "created": "Fri, 9 Apr 2021 12:21:43 GMT", "version": "v1" }, { "created": "Wed, 22 Sep 2021 07:33:58 GMT", "version": "v2" } ]
2021-09-29
[ [ "Ahmed", "Waqas", "" ], [ "Karozas", "Athanasios", "" ], [ "Leontaris", "George K.", "" ] ]
We revisit Higgs inflation in the framework of a minimal extension of the Standard Model gauge symmetry by a $U(1)_{B-L}$ factor. Various aspects are taken into account with particular focus on the role of the supersymmetry breaking (SUSY) scale and the cosmological constraints associated with the gravitino. The scalar potential of the model is considered in the context of no-scale supergravity consisting of the F-part constructed from the K\"ahler function, the D-terms and soft SUSY contributions. We investigate several limiting cases and by varying the SUSY scale from a few TeV up to intermediate energies, for a spectral index around $n_s\sim 0.9655$ and reheating temperature $T_r\le 10^{9}$ GeV we find that the value of the tensor-to-scalar ratio ranges from $r\approx 10^{-3}$ to $10^{-2}$. Furthermore, it is shown that for certain regions of the parameter space the gravitino can live sufficiently long and as such is a potential candidate for a dark matter component. In general, the inflationary scenario is naturally implemented and it is consistent with non-thermal leptogenesis whereas the dominant decay channel of the inflaton yields right-handed neutrinos. Other aspects of cosmology and particle physics phenomenology are briefly discussed. Finally, we investigate the case where the inflaton is initially relaxed in a false minimum and estimate its probability to decay to the true vacuum.
hep-ph/0303081
Milind Vamav Diwan
M.V. Diwan, D. Beavis, Mu-Chun Chen, J. Gallardo, R.L. Hahn, S. Kahn, H. Kirk, W. Marciano, W. Morse, Z. Parsa, N. Samios, Y. Semertzidis, B. Viren, W. Weng, P. Yamin, M. Yeh, W. Frati, K. Lande, A.K. Mann, R.Van Berg, P. Wildenhain, J.R. Klein, I. Mocioiu, R. Shrock, K.T. McDonald
Very Long Baseline Neutrino Oscillation Experiment for Precise Measurements of Mixing Parameters and CP Violating Effects
12 pages, 10 figures
Phys.Rev.D68:012002,2003
10.1103/PhysRevD.68.012002
null
hep-ph
null
We analyze the prospects of a feasible, Brookhaven National Laboratory based, very long baseline (BVLB) neutrino oscillation experiment consisting of a conventional horn produced low energy wide band beam and a detector of 500 kT fiducial mass with modest requirements on event recognition and resolution. Such an experiment is intended primarily to determine CP violating effects in the neutrino sector for 3-generation mixing. We analyze the sensitivity of such an experiment. We conclude that this experiment will allow determination of the CP phase $\delta_{CP}$ and the currently unknown mixing parameter $\theta_{13}$, if $\sin ^2 2 \theta_{13} \geq 0.01$, a value $\sim 15$ times lower than the present experimental upper limit. In addition to $\theta_{13}$ and $\delta_{CP}$, the experiment has great potential for precise measurements of most other parameters in the neutrino mixing matrix including $\Delta m^2_{32}$, $\sin^2 2\theta_{23}$, $\Delta m^2_{21}\times \sin 2 \theta_{12}$, and the mass ordering of neutrinos through the observation of the matter effect in the $\nu_\mu \to \nu_e$ appearance channel.
[ { "created": "Mon, 10 Mar 2003 19:40:18 GMT", "version": "v1" }, { "created": "Fri, 16 May 2003 16:42:34 GMT", "version": "v2" } ]
2008-11-26
[ [ "Diwan", "M. V.", "" ], [ "Beavis", "D.", "" ], [ "Chen", "Mu-Chun", "" ], [ "Gallardo", "J.", "" ], [ "Hahn", "R. L.", "" ], [ "Kahn", "S.", "" ], [ "Kirk", "H.", "" ], [ "Marciano", "W.", "" ], [ "Morse", "W.", "" ], [ "Parsa", "Z.", "" ], [ "Samios", "N.", "" ], [ "Semertzidis", "Y.", "" ], [ "Viren", "B.", "" ], [ "Weng", "W.", "" ], [ "Yamin", "P.", "" ], [ "Yeh", "M.", "" ], [ "Frati", "W.", "" ], [ "Lande", "K.", "" ], [ "Mann", "A. K.", "" ], [ "Van Berg", "R.", "" ], [ "Wildenhain", "P.", "" ], [ "Klein", "J. R.", "" ], [ "Mocioiu", "I.", "" ], [ "Shrock", "R.", "" ], [ "McDonald", "K. T.", "" ] ]
We analyze the prospects of a feasible, Brookhaven National Laboratory based, very long baseline (BVLB) neutrino oscillation experiment consisting of a conventional horn produced low energy wide band beam and a detector of 500 kT fiducial mass with modest requirements on event recognition and resolution. Such an experiment is intended primarily to determine CP violating effects in the neutrino sector for 3-generation mixing. We analyze the sensitivity of such an experiment. We conclude that this experiment will allow determination of the CP phase $\delta_{CP}$ and the currently unknown mixing parameter $\theta_{13}$, if $\sin ^2 2 \theta_{13} \geq 0.01$, a value $\sim 15$ times lower than the present experimental upper limit. In addition to $\theta_{13}$ and $\delta_{CP}$, the experiment has great potential for precise measurements of most other parameters in the neutrino mixing matrix including $\Delta m^2_{32}$, $\sin^2 2\theta_{23}$, $\Delta m^2_{21}\times \sin 2 \theta_{12}$, and the mass ordering of neutrinos through the observation of the matter effect in the $\nu_\mu \to \nu_e$ appearance channel.
hep-ph/9709204
Martti Raidal
Martti Raidal
Bileptons - Present Constraints and Future Prospects at Colliders
6 pages, talk presented in workshop "Beyond the Desert 97", Castle Ringberg
null
null
FTUV/97-55, IFIC/97-57
hep-ph
null
Bosons which couple to two leptons and carry lepton number L=2, generically called bileptons, appear in many extensions of the standard model. We review the present constraints on bilepton parameters coming from low and high energy data. In particular, we point out that the amplitude of $\mu-e$ conversion in nuclei is enhanced by large logarithms if compared with the $\mu\to e\gamma$ one. Bilepton couplings will be tested most stringently at future colliders. For wide range of neutrino masses the cross section of one of the processes $e^-e^- (\mu^-\mu^-)\to \ell_i^-\ell_i^-,$ $i=e,\mu, \tau,$ mediated by scalar triplet bilepton, has such a lower bound that it should be observed at future facilities.
[ { "created": "Mon, 1 Sep 1997 08:23:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Raidal", "Martti", "" ] ]
Bosons which couple to two leptons and carry lepton number L=2, generically called bileptons, appear in many extensions of the standard model. We review the present constraints on bilepton parameters coming from low and high energy data. In particular, we point out that the amplitude of $\mu-e$ conversion in nuclei is enhanced by large logarithms if compared with the $\mu\to e\gamma$ one. Bilepton couplings will be tested most stringently at future colliders. For wide range of neutrino masses the cross section of one of the processes $e^-e^- (\mu^-\mu^-)\to \ell_i^-\ell_i^-,$ $i=e,\mu, \tau,$ mediated by scalar triplet bilepton, has such a lower bound that it should be observed at future facilities.
1303.1189
Stefano Forte
The NNPDF Collaboration: Richard D. Ball, Valerio Bertone, Luigi Del Debbio, Stefano Forte, Alberto Guffanti, Juan Rojo and Maria Ubiali
Theoretical issues in PDF determination and associated uncertainties
18 pages, 13 figures. Final version, to be published in Phys. Lett. B. Tab. 2 added and Fig 13 updated. Several small improvements, including revised discussion of Ref.[24]
null
null
CERN-PH-TH/2013-035, Edinburgh 2013/02, FR-PHENO-2013-003, IFUM-1008-FT, TTK-13-06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study several sources of theoretical uncertainty in the determination of parton distributions (PDFs) which may affect current PDF sets used for precision physics at the Large Hadron Collider, and explain discrepancies between them. We consider in particular the use of fixed-flavor versus variable-flavor number renormalization schemes, higher twist corrections, and nuclear corrections. We perform our study in the framework of the NNPDF2.3 global PDF determination, by quantifying in each case the impact of different theoretical assumptions on the output PDFs. We also study in each case the implications for benchmark cross sections at the LHC. We find that the impact in a global fit of a fixed-flavor number scheme is substantial, the impact of higher twists is negligible, and the impact of nuclear corrections is moderate and circumscribed.
[ { "created": "Tue, 5 Mar 2013 21:01:27 GMT", "version": "v1" }, { "created": "Wed, 8 May 2013 16:40:02 GMT", "version": "v2" } ]
2013-05-09
[ [ "The NNPDF Collaboration", "", "" ], [ "Ball", "Richard D.", "" ], [ "Bertone", "Valerio", "" ], [ "Del Debbio", "Luigi", "" ], [ "Forte", "Stefano", "" ], [ "Guffanti", "Alberto", "" ], [ "Rojo", "Juan", "" ], [ "Ubiali", "Maria", "" ] ]
We study several sources of theoretical uncertainty in the determination of parton distributions (PDFs) which may affect current PDF sets used for precision physics at the Large Hadron Collider, and explain discrepancies between them. We consider in particular the use of fixed-flavor versus variable-flavor number renormalization schemes, higher twist corrections, and nuclear corrections. We perform our study in the framework of the NNPDF2.3 global PDF determination, by quantifying in each case the impact of different theoretical assumptions on the output PDFs. We also study in each case the implications for benchmark cross sections at the LHC. We find that the impact in a global fit of a fixed-flavor number scheme is substantial, the impact of higher twists is negligible, and the impact of nuclear corrections is moderate and circumscribed.
hep-ph/0202119
Ahmet T. Alan
A.T.Alan and A.Senol
Single Top Production at HERA and THERA
8 pages, 3 figures, RevTeX4, references added
Europhys.Lett. 59 (2002) 669-673
10.1209/epl/i2002-00177-6
null
hep-ph
null
We study the single top production mediated by flavor changing neutral current via both of the $t-q-\gamma$ and $t-q-Z$ vertices (here q represents c and u quarks) in ep collisions at two colliders HERA and THERA. Contribution of the second vertex becomes even more important as the couplings take more improved values provided by the higher luminosities of colliders. In addition to these improvements if the CM energy of the collider is increased, the production will be dominated by the anomalous $t-q-Z$ vertex.
[ { "created": "Wed, 13 Feb 2002 12:00:42 GMT", "version": "v1" }, { "created": "Fri, 15 Feb 2002 10:57:34 GMT", "version": "v2" } ]
2009-11-07
[ [ "Alan", "A. T.", "" ], [ "Senol", "A.", "" ] ]
We study the single top production mediated by flavor changing neutral current via both of the $t-q-\gamma$ and $t-q-Z$ vertices (here q represents c and u quarks) in ep collisions at two colliders HERA and THERA. Contribution of the second vertex becomes even more important as the couplings take more improved values provided by the higher luminosities of colliders. In addition to these improvements if the CM energy of the collider is increased, the production will be dominated by the anomalous $t-q-Z$ vertex.
0711.4747
Pietro Colangelo
P. Colangelo, F. De Fazio, F. Jugeau, S. Nicotri
Investigating AdS/QCD duality through scalar glueball correlators
LaTex, 24 pages, 1 figure, published version
Int. J. Mod. Phys. A Vol. 24, No. 22 (2009) 4177-4192
null
BARI-TH/07-585, DCPT/09/130, IPPP/09/65
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate AdS/QCD duality for the two-point correlation function of the lowest dimension scalar glueball operator, in the case of the IR soft wall model. We point out the role of the boundary conditions for the bulk-to-boundary propagator in determining the gluon condensates. We show that a low energy QCD theorem can be obtained within the AdS approach, together with a gluon condensate close to the commonly accepted value and robust against perturbation of the background dilaton field.
[ { "created": "Thu, 29 Nov 2007 16:42:40 GMT", "version": "v1" }, { "created": "Thu, 3 Sep 2009 11:33:02 GMT", "version": "v2" } ]
2009-09-03
[ [ "Colangelo", "P.", "" ], [ "De Fazio", "F.", "" ], [ "Jugeau", "F.", "" ], [ "Nicotri", "S.", "" ] ]
We investigate AdS/QCD duality for the two-point correlation function of the lowest dimension scalar glueball operator, in the case of the IR soft wall model. We point out the role of the boundary conditions for the bulk-to-boundary propagator in determining the gluon condensates. We show that a low energy QCD theorem can be obtained within the AdS approach, together with a gluon condensate close to the commonly accepted value and robust against perturbation of the background dilaton field.
1007.0498
Emanuele Re
Emanuele Re
Single-top production with the POWHEG method
5 pages, 2 figures. Submitted to the proceedings of the XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects, DIS 2010, April 19-23, 2010, Firenze, Italy
PoS DIS2010:172,2010
null
IPPP/10/46, DCPT/10/92
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe briefly the POWHEG method and present results for single-top s- and t-channel production at hadron colliders.
[ { "created": "Sat, 3 Jul 2010 13:59:54 GMT", "version": "v1" } ]
2010-11-19
[ [ "Re", "Emanuele", "" ] ]
We describe briefly the POWHEG method and present results for single-top s- and t-channel production at hadron colliders.
2004.00024
Hongxi Xing
Hui Zhang, Jinfeng Liao, Enke Wang, Qian Wang, Hongxi Xing
Deciphering the nature of X(3872) in heavy ion collisions
5 pages, 5 figures, published version in Phys. Rev. Lett
Phys. Rev. Lett. 126, 012301 (2021)
10.1103/PhysRevLett.126.012301
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exploring the nature of exotic multiquark candidates such as the $X(3872)$ plays a pivotal role in understanding quantum chromodynamics (QCD). Despite significant efforts, consensus on their internal structures is still lacking. As a prime example, it remains a pressing open question to decipher the $X(3872)$ state between two popular exotic configurations: a loose hadronic molecule or a compact tetraquark. We demonstrate a novel approach to help address this problem by studying the $X(3872)$ production in heavy ion collisions, where a hot fireball with ample light as well as charm (anti-)quarks is available for producing the exotics. Adopting a multiphase transport model (AMPT) for describing such collisions and implementing appropriate production mechanism of either molecule or tetraquark picture, we compute and compare a series of observables for $X(3872)$ in Pb-Pb collisions at the Large Hadron Collider. We find the fireball volume plays a crucial role, leading to a 2-order-of-magnitude difference in the $X(3872)$ yield and a markedly different centrality dependence between hadronic molecules and compact tetraquarks, thus offering a unique opportunity for distinguishing the two scenarios. We also make the first prediction of $X(3872)$ elliptic flow coefficient to be tested by future experimental measurements.
[ { "created": "Tue, 31 Mar 2020 18:00:06 GMT", "version": "v1" }, { "created": "Mon, 8 Feb 2021 05:28:33 GMT", "version": "v2" } ]
2021-02-09
[ [ "Zhang", "Hui", "" ], [ "Liao", "Jinfeng", "" ], [ "Wang", "Enke", "" ], [ "Wang", "Qian", "" ], [ "Xing", "Hongxi", "" ] ]
Exploring the nature of exotic multiquark candidates such as the $X(3872)$ plays a pivotal role in understanding quantum chromodynamics (QCD). Despite significant efforts, consensus on their internal structures is still lacking. As a prime example, it remains a pressing open question to decipher the $X(3872)$ state between two popular exotic configurations: a loose hadronic molecule or a compact tetraquark. We demonstrate a novel approach to help address this problem by studying the $X(3872)$ production in heavy ion collisions, where a hot fireball with ample light as well as charm (anti-)quarks is available for producing the exotics. Adopting a multiphase transport model (AMPT) for describing such collisions and implementing appropriate production mechanism of either molecule or tetraquark picture, we compute and compare a series of observables for $X(3872)$ in Pb-Pb collisions at the Large Hadron Collider. We find the fireball volume plays a crucial role, leading to a 2-order-of-magnitude difference in the $X(3872)$ yield and a markedly different centrality dependence between hadronic molecules and compact tetraquarks, thus offering a unique opportunity for distinguishing the two scenarios. We also make the first prediction of $X(3872)$ elliptic flow coefficient to be tested by future experimental measurements.
hep-ph/0403065
Ren-Jie Zhang
Tatsuo Kobayashi, Stuart Raby, Ren-Jie Zhang
Constructing 5d orbifold grand unified theories from heterotic strings
15 pages, 3 figures, 1 table, revtex4
Phys.Lett.B593:262-270,2004
10.1016/j.physletb.2004.04.058
KUNS-1901, MCTP-04-12, OHSTPY-HEP-T-04-003
hep-ph hep-th
null
A three-generation Pati-Salam model is constructed by compactifying the heterotic string on a particular T^6/Z_6 Abelian symmetric orbifold with two discrete Wilson lines. The compactified space is taken to be the Lie algebra lattice G_2+SU(3)+SO(4). When one dimension of the SO(4) lattice is large compared to the string scale, this model reproduces many features of a 5d SO(10) grand unified theory compactified on an S^1/Z_2 orbifold. (Of course, with two large extra dimensions we can obtain a 6d SO(10) grand unified theory.) We identify the orbifold parities and other ingredients of the orbifold grand unified theories in the string model. Our construction provides a UV completion of orbifold grand unified theories, and gives new insights into both field theoretical and string theoretical constructions.
[ { "created": "Fri, 5 Mar 2004 19:00:56 GMT", "version": "v1" }, { "created": "Fri, 5 Mar 2004 21:29:33 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kobayashi", "Tatsuo", "" ], [ "Raby", "Stuart", "" ], [ "Zhang", "Ren-Jie", "" ] ]
A three-generation Pati-Salam model is constructed by compactifying the heterotic string on a particular T^6/Z_6 Abelian symmetric orbifold with two discrete Wilson lines. The compactified space is taken to be the Lie algebra lattice G_2+SU(3)+SO(4). When one dimension of the SO(4) lattice is large compared to the string scale, this model reproduces many features of a 5d SO(10) grand unified theory compactified on an S^1/Z_2 orbifold. (Of course, with two large extra dimensions we can obtain a 6d SO(10) grand unified theory.) We identify the orbifold parities and other ingredients of the orbifold grand unified theories in the string model. Our construction provides a UV completion of orbifold grand unified theories, and gives new insights into both field theoretical and string theoretical constructions.
2111.12108
Seokhoon Yun
Francesco D'Eramo, Seokhoon Yun
Flavor Violating Axions in the Early Universe
6 pages, 4 figures, journal version
Phys. Rev. D 105 (2022), 075002
10.1103/PhysRevD.105.075002
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavor violating axion couplings can be in action before recombination, and they can fill the early universe with an additional radiation component. Working within a model-independent framework, we consider an effective field theory for the axion field and quantify axion production. Current cosmological data exclude already a fraction of the available parameter space, and the bounds will improve significantly with future CMB-S4 surveys. Remarkably, we find that future cosmological bounds will be comparable or even stronger than the ones obtained in our terrestrial laboratories.
[ { "created": "Tue, 23 Nov 2021 19:01:52 GMT", "version": "v1" }, { "created": "Mon, 28 Feb 2022 17:58:46 GMT", "version": "v2" }, { "created": "Thu, 7 Apr 2022 14:37:59 GMT", "version": "v3" } ]
2022-04-08
[ [ "D'Eramo", "Francesco", "" ], [ "Yun", "Seokhoon", "" ] ]
Flavor violating axion couplings can be in action before recombination, and they can fill the early universe with an additional radiation component. Working within a model-independent framework, we consider an effective field theory for the axion field and quantify axion production. Current cosmological data exclude already a fraction of the available parameter space, and the bounds will improve significantly with future CMB-S4 surveys. Remarkably, we find that future cosmological bounds will be comparable or even stronger than the ones obtained in our terrestrial laboratories.
hep-ph/9902442
Bruno Machet
Q. Ho-Kim, B. Machet, X.Y. Pham
The decays "neutrino{heavy} -> neutrino{light} + photon" and "neutrino{heavy} -> neutrino{light} e+ e-" of massive neutrinos
12 pages, LaTeX 2e (epsf) with 9 postscript figures and one logo. Some comments and references added
Eur.Phys.J.C13:117-123,2000
10.1007/s100520000292
PAR-LPTHE-99/06
hep-ph
null
If, as recently reported by the Super-Kamiokande collaboration, the neutrinos are massive, the heaviest one would not be stable and, though chargeless, could in particular decay into a lighter neutrino and a photon by quantum loop effects. The corresponding rate is computed in the standard model with massive Dirac neutrinos as a function of the neutrino masses and mixing angles. The lifetime of the decaying neutrino is estimated to be approximately 10^44 years for a mass 5 10^{-2} eV. If kinematically possible, the decay of a heavy neutrino into a lighter one plus an e+ e- pair occurs at tree level and its one-loop radiative corrections get enhanced by a large logarithm of the electron mass acting as an infrared cutoff. It then largely dominates the photonic mode by several orders of magnitude, corresponding to a lifetime approximately equal to 10^{-2} year for a mass 1.1 MeV.
[ { "created": "Tue, 23 Feb 1999 14:33:04 GMT", "version": "v1" }, { "created": "Tue, 8 Jun 1999 13:32:40 GMT", "version": "v2" } ]
2015-06-25
[ [ "Ho-Kim", "Q.", "" ], [ "Machet", "B.", "" ], [ "Pham", "X. Y.", "" ] ]
If, as recently reported by the Super-Kamiokande collaboration, the neutrinos are massive, the heaviest one would not be stable and, though chargeless, could in particular decay into a lighter neutrino and a photon by quantum loop effects. The corresponding rate is computed in the standard model with massive Dirac neutrinos as a function of the neutrino masses and mixing angles. The lifetime of the decaying neutrino is estimated to be approximately 10^44 years for a mass 5 10^{-2} eV. If kinematically possible, the decay of a heavy neutrino into a lighter one plus an e+ e- pair occurs at tree level and its one-loop radiative corrections get enhanced by a large logarithm of the electron mass acting as an infrared cutoff. It then largely dominates the photonic mode by several orders of magnitude, corresponding to a lifetime approximately equal to 10^{-2} year for a mass 1.1 MeV.
2110.15270
Lianrong Dai
L. R. Dai, R. Molina, E. Oset
Prediction of new $T_{cc}$ states of $D^{*} D^{*}$ and $D^{*}_s D^{*}$ molecular nature
21 pages,12 figures,1 table. Minor changes made and references added
null
10.1103/PhysRevD.105.016029
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the theoretical framework used of describe the $T_{cc}$ state as a molecular state of $D^* D$ and make predictions for the $D^*D^*$ and $D^*_s D^*$ systems, finding that they lead to bound states only in the $J^P=1^+$ channel. Using input needed to describe the $T_{cc}$ state, basically one parameter to regularize the loops of the Bethe-Salpeter equation, we find bound states with bindings of the order of the MeV and similar widths for $D^*D^*$ system, while the $D^{*}_s D^{*}$ system develops a strong cusp around threshold.
[ { "created": "Thu, 28 Oct 2021 16:27:06 GMT", "version": "v1" }, { "created": "Fri, 5 Nov 2021 15:26:37 GMT", "version": "v2" } ]
2022-02-09
[ [ "Dai", "L. R.", "" ], [ "Molina", "R.", "" ], [ "Oset", "E.", "" ] ]
We extend the theoretical framework used of describe the $T_{cc}$ state as a molecular state of $D^* D$ and make predictions for the $D^*D^*$ and $D^*_s D^*$ systems, finding that they lead to bound states only in the $J^P=1^+$ channel. Using input needed to describe the $T_{cc}$ state, basically one parameter to regularize the loops of the Bethe-Salpeter equation, we find bound states with bindings of the order of the MeV and similar widths for $D^*D^*$ system, while the $D^{*}_s D^{*}$ system develops a strong cusp around threshold.
1202.6073
Pedro Machado
Roni Harnik (Fermilab), Joachim Kopp (Fermilab), Pedro A. N. Machado (University of S\~ao Paulo, IPhT CEA-Saclay, Fermilab)
Exploring nu signals in dark matter detectors
38 pages, 8 figures, 1 table; v3: eq 3 and nuclear recoil plots corrected, footnote added, conclusions unchanged
JCAP 07 (2012) 026
10.1088/1475-7516/2012/07/026
FERMILAB-PUB-12-048-T
hep-ph astro-ph.SR hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate standard and non-standard solar neutrino signals in direct dark matter detection experiments. It is well known that even without new physics, scattering of solar neutrinos on nuclei or electrons is an irreducible background for direct dark matter searches, once these experiments each the ton scale. Here, we entertain the possibility that neutrino interactions are enhanced by new physics, such as new light force carriers (for instance a "dark photon") or neutrino magnetic moments. We consider models with only the three standard neutrino flavors, as well as scenarios with extra sterile neutrinos. We find that low-energy neutrino--electron and neutrino--nucleus scattering rates can be enhanced by several orders of magnitude, potentially enough to explain the event excesses observed in CoGeNT and CRESST. We also investigate temporal modulation in these neutrino signals, which can arise from geometric effects, oscillation physics, non-standard neutrino energy loss, and direction-dependent detection efficiencies. We emphasize that, in addition to providing potential explanations for existing signals, models featuring new physics in the neutrino sector can also be very relevant to future dark matter searches, where, on the one hand, they can be probed and constrained, but on the other hand, their signatures could also be confused with dark matter signals.
[ { "created": "Mon, 27 Feb 2012 21:18:57 GMT", "version": "v1" }, { "created": "Wed, 11 Jul 2012 16:52:10 GMT", "version": "v2" }, { "created": "Mon, 3 Aug 2015 15:27:01 GMT", "version": "v3" } ]
2015-08-04
[ [ "Harnik", "Roni", "", "Fermilab" ], [ "Kopp", "Joachim", "", "Fermilab" ], [ "Machado", "Pedro A. N.", "", "University of São Paulo, IPhT CEA-Saclay, Fermilab" ] ]
We investigate standard and non-standard solar neutrino signals in direct dark matter detection experiments. It is well known that even without new physics, scattering of solar neutrinos on nuclei or electrons is an irreducible background for direct dark matter searches, once these experiments each the ton scale. Here, we entertain the possibility that neutrino interactions are enhanced by new physics, such as new light force carriers (for instance a "dark photon") or neutrino magnetic moments. We consider models with only the three standard neutrino flavors, as well as scenarios with extra sterile neutrinos. We find that low-energy neutrino--electron and neutrino--nucleus scattering rates can be enhanced by several orders of magnitude, potentially enough to explain the event excesses observed in CoGeNT and CRESST. We also investigate temporal modulation in these neutrino signals, which can arise from geometric effects, oscillation physics, non-standard neutrino energy loss, and direction-dependent detection efficiencies. We emphasize that, in addition to providing potential explanations for existing signals, models featuring new physics in the neutrino sector can also be very relevant to future dark matter searches, where, on the one hand, they can be probed and constrained, but on the other hand, their signatures could also be confused with dark matter signals.
2103.12766
Natascia Vignaroli
Salvatore Bottaro, Alessandro Strumia, Natascia Vignaroli
Minimal Dark Matter bound states at future colliders
v2, to appear on JHEP
JHEP 06 (2021) 143
10.1007/JHEP06(2021)143
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The hypothesis that Dark Matter is one electroweak multiplet leads to predictive candidates with multi-TeV masses that can form electroweak bound states. Bound states with the same quantum numbers as electroweak vectors are found to be especially interesting, as they can be produced resonantly with large cross sections at lepton colliders. Such bound states exist e.g. if DM is an automatically stable fermionic weak 5-plet with mass $M \approx$ 14 TeV such that the DM abundance is reproduced thermally. In this model, a muon collider could resolve three such bound states. Production rates are so large that details of DM spectroscopy can be probed with larger statistics: we compute the characteristic pattern of single and multiple $\gamma$ lines.
[ { "created": "Tue, 23 Mar 2021 18:07:24 GMT", "version": "v1" }, { "created": "Fri, 11 Jun 2021 10:44:54 GMT", "version": "v2" } ]
2021-06-28
[ [ "Bottaro", "Salvatore", "" ], [ "Strumia", "Alessandro", "" ], [ "Vignaroli", "Natascia", "" ] ]
The hypothesis that Dark Matter is one electroweak multiplet leads to predictive candidates with multi-TeV masses that can form electroweak bound states. Bound states with the same quantum numbers as electroweak vectors are found to be especially interesting, as they can be produced resonantly with large cross sections at lepton colliders. Such bound states exist e.g. if DM is an automatically stable fermionic weak 5-plet with mass $M \approx$ 14 TeV such that the DM abundance is reproduced thermally. In this model, a muon collider could resolve three such bound states. Production rates are so large that details of DM spectroscopy can be probed with larger statistics: we compute the characteristic pattern of single and multiple $\gamma$ lines.
2405.19557
Anatoly Borisov
Anatoly V. Borisov
Electron radiation in a constant background field simulating a Lorentz-violating vacuum
11 pages, no figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The power and the probability of electromagnetic radiation from an electron in a constant background tensor field violating Lorentz invariance are calculated. The case of a background field of the quasielectric type is considered. The angular distribution and the polarization of the radiation are studied. Using present experimental constraints on the background field strength, it is shown that the radiation effect can manifest itself under astrophysical conditions at ultrahigh electron energy.
[ { "created": "Wed, 29 May 2024 22:53:31 GMT", "version": "v1" } ]
2024-05-31
[ [ "Borisov", "Anatoly V.", "" ] ]
The power and the probability of electromagnetic radiation from an electron in a constant background tensor field violating Lorentz invariance are calculated. The case of a background field of the quasielectric type is considered. The angular distribution and the polarization of the radiation are studied. Using present experimental constraints on the background field strength, it is shown that the radiation effect can manifest itself under astrophysical conditions at ultrahigh electron energy.
hep-ph/9307302
Yuji Koike
Y. Koike
rho, omega, phi-Nucleon Scattering Lengths from QCD Sum Rules
Latex file. 12 pages. One figure not modified. More expanded discussion which clarify the origin of the discrepancy with Hatsuda-Lee is added. Phys.Rev.C in press
Phys.Rev.C51:1488-1493,1995
10.1103/PhysRevC.51.1488
null
hep-ph nucl-th
null
The QCD sum rule method is applied to derive a formula for the rho, omega, phi meson-nucleon spin-isospin-averaged scattering lengths $a_{\rho,\omega,\phi}$. We found that the crucial matrix elements are $\langle\bar{q}\gamma_\mu D_\nu q\rangle_N$ ($q=u,d$) (twist-2 nucleon matrix element) for $a_{\rho,\omega}$ and $m_s\langle\bar{s}s\rangle_N$ for $a_\phi$, and obtained $a_\rho =0.14\pm 0.07$ fm, $a_\omega =0.11\pm 0.06$ fm and $a_\phi =0.035\pm 0.020$ fm. These small numbers originate from a common factor $1/(m_N+m_{\rho,\omega,\phi})$. Our result suggests a slight increase ($< 60$ MeV for $\rho$, $\omega$, and $<15$ MeV for $\phi$) of the effective mass of these vector mesons in the nuclear matter (in the {\it dilute} nucleon gas approximation). The origin of the discrepancy with the previous study was clarified.
[ { "created": "Tue, 20 Jul 1993 03:13:28 GMT", "version": "v1" }, { "created": "Wed, 21 Dec 1994 11:15:04 GMT", "version": "v2" } ]
2008-11-26
[ [ "Koike", "Y.", "" ] ]
The QCD sum rule method is applied to derive a formula for the rho, omega, phi meson-nucleon spin-isospin-averaged scattering lengths $a_{\rho,\omega,\phi}$. We found that the crucial matrix elements are $\langle\bar{q}\gamma_\mu D_\nu q\rangle_N$ ($q=u,d$) (twist-2 nucleon matrix element) for $a_{\rho,\omega}$ and $m_s\langle\bar{s}s\rangle_N$ for $a_\phi$, and obtained $a_\rho =0.14\pm 0.07$ fm, $a_\omega =0.11\pm 0.06$ fm and $a_\phi =0.035\pm 0.020$ fm. These small numbers originate from a common factor $1/(m_N+m_{\rho,\omega,\phi})$. Our result suggests a slight increase ($< 60$ MeV for $\rho$, $\omega$, and $<15$ MeV for $\phi$) of the effective mass of these vector mesons in the nuclear matter (in the {\it dilute} nucleon gas approximation). The origin of the discrepancy with the previous study was clarified.
hep-ph/9910341
Christophe Royon
F. D\'eliot, C. Royon, E. Perez (DAPNIA-SPP, Saclay), G. Moreau, M. Chemtob (SPhT Saclay)
Resonant sneutrino production at Tevatron Run II
4 pages
Phys.Lett. B475 (2000) 184-189
10.1016/S0370-2693(00)00065-4
null
hep-ph
null
We consider the single chargino production at Tevatron $p \bar p \to \tilde \nu_i \to \tilde \chi^{\pm}_1 l_i^{\mp}$ as induced by the resonant sneutrino production via a dominant \RPV coupling of type $\l'_{ijk} L_i Q_j D_k^c$. Within a supergravity model, we study the three leptons final state. The comparison with the expected background demonstrate that this signature allows to extend the sensitivity on the \susyq mass spectrum beyond the present LEP limits and to probe the relevant \RPV coupling down to values one order of magnitude smaller than the most stringent low energy indirect bounds. The trilepton signal offers also the opportunity to reconstruct the neutralino mass in a model independent way with good accuracy.
[ { "created": "Thu, 14 Oct 1999 15:27:53 GMT", "version": "v1" } ]
2009-10-31
[ [ "Déliot", "F.", "", "DAPNIA-SPP, Saclay" ], [ "Royon", "C.", "", "DAPNIA-SPP, Saclay" ], [ "Perez", "E.", "", "DAPNIA-SPP, Saclay" ], [ "Moreau", "G.", "", "SPhT Saclay" ], [ "Chemtob", "M.", "", "SPhT Saclay" ] ]
We consider the single chargino production at Tevatron $p \bar p \to \tilde \nu_i \to \tilde \chi^{\pm}_1 l_i^{\mp}$ as induced by the resonant sneutrino production via a dominant \RPV coupling of type $\l'_{ijk} L_i Q_j D_k^c$. Within a supergravity model, we study the three leptons final state. The comparison with the expected background demonstrate that this signature allows to extend the sensitivity on the \susyq mass spectrum beyond the present LEP limits and to probe the relevant \RPV coupling down to values one order of magnitude smaller than the most stringent low energy indirect bounds. The trilepton signal offers also the opportunity to reconstruct the neutralino mass in a model independent way with good accuracy.
hep-ph/0111470
Soon-Tae Hong
Soon-Tae Hong
Sum rules for strange form factors and flavor singlet axial charges
15 pages, revised with references added
Phys.Lett. B585 (2004) 122-130
10.1016/j.physletb.2004.01.072
null
hep-ph
null
In chiral models with SU(3) group structure, strange form factors of baryon octet are evaluated by constructing their sum rules to yield theoretical predictions comparable to the recent experimental data of SAMPLE Collaboration. We also study sum rules for the flavor singlet axial currents for the EMC experiment in a modified quark model.
[ { "created": "Fri, 30 Nov 2001 15:48:42 GMT", "version": "v1" }, { "created": "Thu, 10 Jan 2002 16:45:01 GMT", "version": "v2" } ]
2009-11-07
[ [ "Hong", "Soon-Tae", "" ] ]
In chiral models with SU(3) group structure, strange form factors of baryon octet are evaluated by constructing their sum rules to yield theoretical predictions comparable to the recent experimental data of SAMPLE Collaboration. We also study sum rules for the flavor singlet axial currents for the EMC experiment in a modified quark model.
hep-ph/0305233
Francesco Vissani
Francesco Vissani, Mohan Narayan, Veniamin Berezinsky
U(e3) from physics above the GUT scale
10 pages, 1 figure
Phys.Lett. B571 (2003) 209-216
10.1016/j.physletb.2003.07.002
null
hep-ph
null
We consider non-renormalizable 1/M_X interaction terms as a perturbation of the conventional neutrino mass matrix. Particular attention is given to the gravitational interaction with M_X=M_Pl. We find that for the degenerate neutrino mass spectrum, the considered perturbation generates a non-zero U(e3) which is within reach of the high performance neutrino factories and just on the borderline to be of interest for supernova physics. For the hierarchical mass spectrum this effect is small. For 1/M_X interaction terms with M_X about the GUT scale, a detectable U(e3) term is induced for the hierarchical mass spectra also. Numerical estimates are given for all the above mentioned cases and renormalization effects are considered.
[ { "created": "Wed, 21 May 2003 17:56:57 GMT", "version": "v1" } ]
2009-11-10
[ [ "Vissani", "Francesco", "" ], [ "Narayan", "Mohan", "" ], [ "Berezinsky", "Veniamin", "" ] ]
We consider non-renormalizable 1/M_X interaction terms as a perturbation of the conventional neutrino mass matrix. Particular attention is given to the gravitational interaction with M_X=M_Pl. We find that for the degenerate neutrino mass spectrum, the considered perturbation generates a non-zero U(e3) which is within reach of the high performance neutrino factories and just on the borderline to be of interest for supernova physics. For the hierarchical mass spectrum this effect is small. For 1/M_X interaction terms with M_X about the GUT scale, a detectable U(e3) term is induced for the hierarchical mass spectra also. Numerical estimates are given for all the above mentioned cases and renormalization effects are considered.
0802.0022
Nick Kersting
P. Huang, N. Kersting, H.H. Yang (Sichuan U., Chengdu)
Hidden Thresholds: A Technique for Reconstructing New Physics Masses at Hadron Colliders
15 pages, 6 figures; Discussion simplified
null
null
SCUPHY-TH-08002
hep-ph
null
We present an improved method of reconstructing New Physics (NP) masses from invariant mass endpoints. While the traditional method focuses on a single NP decay, our method considers the decays of two or more NP particles ($ABC...$) in a grander decay chain: $ anything \to ABC... \to ... \to jets + leptons$. Though the center-of-mass energy $E_{CM}$ of `anything' varies unpredictably at a hadron collider, a sample of many events nonetheless expresses features of threshold production $E_{CM} = m_A + m_B + ...$: invariant masses constructed from the final jet and lepton momenta are correlated in a way that makes their threshold endpoints visually obvious in a scatterplot. We illustrate this technique for the production of two neutralinos in the MSSM: $anything \to \widetilde{\chi}_{i}^0 \widetilde{\chi}_{j}^0$ ($i,j=2,3,4$) which subsequently decay via on- or off-shell sleptons to four leptons. Assuming the relevant SUSY spectrum is below $1 TeV$ and squarks/gluinos eventually decay to neutralinos, our MC study shows that one low-luminosity year at the LHC ($10-30 fb^{-1}$) can quantitatively determine on- versus off-shell decays and find the relevant neutralino and slepton masses to less than 10 percent.
[ { "created": "Thu, 31 Jan 2008 22:49:03 GMT", "version": "v1" }, { "created": "Sun, 3 Feb 2008 17:20:43 GMT", "version": "v2" }, { "created": "Thu, 22 May 2008 16:11:06 GMT", "version": "v3" } ]
2008-05-22
[ [ "Huang", "P.", "", "Sichuan U., Chengdu" ], [ "Kersting", "N.", "", "Sichuan U., Chengdu" ], [ "Yang", "H. H.", "", "Sichuan U., Chengdu" ] ]
We present an improved method of reconstructing New Physics (NP) masses from invariant mass endpoints. While the traditional method focuses on a single NP decay, our method considers the decays of two or more NP particles ($ABC...$) in a grander decay chain: $ anything \to ABC... \to ... \to jets + leptons$. Though the center-of-mass energy $E_{CM}$ of `anything' varies unpredictably at a hadron collider, a sample of many events nonetheless expresses features of threshold production $E_{CM} = m_A + m_B + ...$: invariant masses constructed from the final jet and lepton momenta are correlated in a way that makes their threshold endpoints visually obvious in a scatterplot. We illustrate this technique for the production of two neutralinos in the MSSM: $anything \to \widetilde{\chi}_{i}^0 \widetilde{\chi}_{j}^0$ ($i,j=2,3,4$) which subsequently decay via on- or off-shell sleptons to four leptons. Assuming the relevant SUSY spectrum is below $1 TeV$ and squarks/gluinos eventually decay to neutralinos, our MC study shows that one low-luminosity year at the LHC ($10-30 fb^{-1}$) can quantitatively determine on- versus off-shell decays and find the relevant neutralino and slepton masses to less than 10 percent.
hep-ph/0207169
null
M. I. Kotsky, L. N. Lipatov, A. Principe, M. I. Vyazovsky
Radiative corrections to the quark-gluon-Reggeized quark vertex in QCD
13 pages, LaTeX, uses axodraw.sty
Nucl.Phys. B648 (2003) 277-292
10.1016/S0550-3213(02)00967-7
BUDKERINP /2002-32
hep-ph
null
This paper is devoted to the calculation of the quark-gluon-Reggeized quark effective vertex in perturbative QCD in the next-to-leading order. The case of QCD with massive quarks is considered. This vertex has a number of applications, in particular, the result can be used for determination of the next-to-leading correction to the massive Reggeized quark trajectory.
[ { "created": "Sun, 14 Jul 2002 02:55:48 GMT", "version": "v1" } ]
2009-11-07
[ [ "Kotsky", "M. I.", "" ], [ "Lipatov", "L. N.", "" ], [ "Principe", "A.", "" ], [ "Vyazovsky", "M. I.", "" ] ]
This paper is devoted to the calculation of the quark-gluon-Reggeized quark effective vertex in perturbative QCD in the next-to-leading order. The case of QCD with massive quarks is considered. This vertex has a number of applications, in particular, the result can be used for determination of the next-to-leading correction to the massive Reggeized quark trajectory.
1909.05769
Florent Scarpa
Florent Scarpa, Dani\"el Boer, Miguel G. Echevarria, Jean-Philippe Lansberg, Cristian Pisano, Marc Schlegel
Studies of gluon TMDs and their evolution using quarkonium-pair production at the LHC
16 pages, 6 figures
null
10.1140/epjc/s10052-020-7619-1
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
$J/\psi$- or $\Upsilon$-pair production at the LHC are promising processes to study the gluon transverse momentum distributions (TMDs) which remain very poorly known. In this article, we improve on previous results by including the TMD evolution in the computation of the observables such as the pair-transverse-momentum spectrum and asymmetries arising from the linear polarization of gluons inside unpolarized protons. We show that the azimuthal asymmetries generated by the gluon polarization are reduced compared to the tree level case but are still of measurable size (in the 5%-10% range). Such asymmetries should be measurable in the available data sets of $J/\psi$ pairs and in the future data sets of the high-luminosity LHC for $\Upsilon$ pairs.
[ { "created": "Thu, 12 Sep 2019 15:57:58 GMT", "version": "v1" } ]
2020-02-26
[ [ "Scarpa", "Florent", "" ], [ "Boer", "Daniël", "" ], [ "Echevarria", "Miguel G.", "" ], [ "Lansberg", "Jean-Philippe", "" ], [ "Pisano", "Cristian", "" ], [ "Schlegel", "Marc", "" ] ]
$J/\psi$- or $\Upsilon$-pair production at the LHC are promising processes to study the gluon transverse momentum distributions (TMDs) which remain very poorly known. In this article, we improve on previous results by including the TMD evolution in the computation of the observables such as the pair-transverse-momentum spectrum and asymmetries arising from the linear polarization of gluons inside unpolarized protons. We show that the azimuthal asymmetries generated by the gluon polarization are reduced compared to the tree level case but are still of measurable size (in the 5%-10% range). Such asymmetries should be measurable in the available data sets of $J/\psi$ pairs and in the future data sets of the high-luminosity LHC for $\Upsilon$ pairs.
2405.04838
Benoit Loiseau
J.-P. Dedonder, R. Kami\'nski, L. Le\'sniak, B. Loiseau, P. \.Zenczykowski
Amplitude analysis of $ B^0 \to K^0_S K^+ K^-$ decays in a quasi-two-body QCD factorization approach
32 pages, 9 figures, submitted to Phys. Rev. D
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
The $B^0 \to K^0_S K^+ K^- $ decay amplitude is derived within a quasi-two-body QCD factorization framework in terms of kaon form factors and $B^0$ to two-kaon-transition functions. The final state kaon-kaon interactions in the $S$, $P$, and $D$ waves are taken into account. The unitarity constraints are satisfied for the two kaons in scalar states. It is shown that with few terms of the full decay amplitude one may reach a fair agreement with the total branching fraction and Dalitz-plot projections published in 2010 by the Belle Collaboration and in 2012 by the $\textit{BABAR}$ Collaboration. With 13 free parameters, our model fits the corresponding 422 data with a $\chi^2$ of 583.6 which leads to a $\chi^2$ per degree of freedom equal to 1.43. The dominant branching fraction arises from the $f_0(K^+K^-) K^0_S$ mode with 83.0$\%$ of the total branching. The next important mode is dominated by $\phi K^0_S$ plus small $\omega K^0_S$ and $\rho^0 K^0_S$ modes with 18.3$\%$ of the total. Then follows the $a_0^\pm K^\mp$ mode with 6.2$\%$. Adding the other smaller modes, the total percentage sum is 107.7$\%$ which indicates a small interference contribution. In most regions of the Dalitz plot, our model gives rather small $CP$ asymmetry, but in some parts its values can be large and positive or negative. Its predicted total value is equal to -0.11$\%$. The calculated time dependent $\textit{CP}$-asymmetry parameters agree, within errors, with those obtained by the $\textit{BABAR}$ analysis. Our model amplitude can be the basis for a parametrization in experimental Dalitz plot analyses of LHCb and Belle II Collaborations.
[ { "created": "Wed, 8 May 2024 06:24:34 GMT", "version": "v1" } ]
2024-05-13
[ [ "Dedonder", "J. -P.", "" ], [ "Kamiński", "R.", "" ], [ "Leśniak", "L.", "" ], [ "Loiseau", "B.", "" ], [ "Żenczykowski", "P.", "" ] ]
The $B^0 \to K^0_S K^+ K^- $ decay amplitude is derived within a quasi-two-body QCD factorization framework in terms of kaon form factors and $B^0$ to two-kaon-transition functions. The final state kaon-kaon interactions in the $S$, $P$, and $D$ waves are taken into account. The unitarity constraints are satisfied for the two kaons in scalar states. It is shown that with few terms of the full decay amplitude one may reach a fair agreement with the total branching fraction and Dalitz-plot projections published in 2010 by the Belle Collaboration and in 2012 by the $\textit{BABAR}$ Collaboration. With 13 free parameters, our model fits the corresponding 422 data with a $\chi^2$ of 583.6 which leads to a $\chi^2$ per degree of freedom equal to 1.43. The dominant branching fraction arises from the $f_0(K^+K^-) K^0_S$ mode with 83.0$\%$ of the total branching. The next important mode is dominated by $\phi K^0_S$ plus small $\omega K^0_S$ and $\rho^0 K^0_S$ modes with 18.3$\%$ of the total. Then follows the $a_0^\pm K^\mp$ mode with 6.2$\%$. Adding the other smaller modes, the total percentage sum is 107.7$\%$ which indicates a small interference contribution. In most regions of the Dalitz plot, our model gives rather small $CP$ asymmetry, but in some parts its values can be large and positive or negative. Its predicted total value is equal to -0.11$\%$. The calculated time dependent $\textit{CP}$-asymmetry parameters agree, within errors, with those obtained by the $\textit{BABAR}$ analysis. Our model amplitude can be the basis for a parametrization in experimental Dalitz plot analyses of LHCb and Belle II Collaborations.
1608.03765
Radek \v{Z}leb\v{c}\'ik
Leif L\"onnblad and Radek \v{Z}leb\v{c}\'ik
Generation of central exclusive final states
null
null
10.1140/epjc/s10052-016-4513-y
MCnet-16-35
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a scheme for the generation of central exclusive final states in the Pythia 8 program. The implementation allows for the investigation of higher order corrections to such exclusive processes as approximated by the initial-state parton shower in Pythia 8. To achieve this, the spin and colour decomposition of the initial-state shower has been worked out, in order to determine the probability that a partonic state generated from an inclusive sub-process followed by a series of initial-state parton splittings can be considered as an approximation of an exclusive colour- and spin-singlet process. We use our implementation to investigate effects of parton showers on some examples of central exclusive processes, and find sizeable effects on di-jet production, while the effects on e.g. central exclusive Higgs production are minor.
[ { "created": "Fri, 12 Aug 2016 12:02:41 GMT", "version": "v1" }, { "created": "Mon, 15 Aug 2016 13:02:13 GMT", "version": "v2" }, { "created": "Mon, 7 Nov 2016 09:59:57 GMT", "version": "v3" } ]
2016-12-21
[ [ "Lönnblad", "Leif", "" ], [ "Žlebčík", "Radek", "" ] ]
We present a scheme for the generation of central exclusive final states in the Pythia 8 program. The implementation allows for the investigation of higher order corrections to such exclusive processes as approximated by the initial-state parton shower in Pythia 8. To achieve this, the spin and colour decomposition of the initial-state shower has been worked out, in order to determine the probability that a partonic state generated from an inclusive sub-process followed by a series of initial-state parton splittings can be considered as an approximation of an exclusive colour- and spin-singlet process. We use our implementation to investigate effects of parton showers on some examples of central exclusive processes, and find sizeable effects on di-jet production, while the effects on e.g. central exclusive Higgs production are minor.
1907.08760
Guo-Liang Yu
Guo-Liang Yu, Zhi-Gang Wang
The analysis of the excited bottom and bottom strange states $B_{1}(5721)$, $B_{2}^{*}(5747)$, $B_{s1}(5830)$, $B_{s2}^{*}(5840)$, $B_{J}(5840)$ and $B_{J}(5970)$ in B meson family
null
Chin.Phys.C 44 (2020) 3, 033103
10.1088/1674-1137/44/3/033103
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to make a further confirmation about the assignments of the excited bottom and bottom strange mesons $B_{1}(5721)$, $B_{2}^{*}(5747)$, $B_{s1}(5830)$, $B_{s2}^{*}(5840)$ and meanwhile identify the possible assignments of $B_{J}(5840)$, $B_{J}(5970)$, we study the strong decays of these states with the $^{3}P_{0}$ decay model. Our analysis support $B_{1}(5721)$ and $B_{2}^{*}(5747)$ to be the $1P_{1}'$ and $1^{3}P_{2}$ assignments and the $B_{s1}(5830)$, $B_{s2}^{*}(5840)$ to be the strange partner of $B_{1}(5721)$ and $B_{2}^{*}(5747)$. Besides, we tentatively identify the recently observed $B_{J}(5840)$, $B_{J}(5970)$ as the $2^{3}S_{1}$ and $1^{3}D_{3}$ states, respectively. It is noticed that this conclusion needs further confirmation by measuring the decay channel to $B\pi$ of $B_{J}(5840)$ and $B_{J}(5970)$ in experiments.
[ { "created": "Sat, 20 Jul 2019 05:26:23 GMT", "version": "v1" } ]
2023-04-14
[ [ "Yu", "Guo-Liang", "" ], [ "Wang", "Zhi-Gang", "" ] ]
In order to make a further confirmation about the assignments of the excited bottom and bottom strange mesons $B_{1}(5721)$, $B_{2}^{*}(5747)$, $B_{s1}(5830)$, $B_{s2}^{*}(5840)$ and meanwhile identify the possible assignments of $B_{J}(5840)$, $B_{J}(5970)$, we study the strong decays of these states with the $^{3}P_{0}$ decay model. Our analysis support $B_{1}(5721)$ and $B_{2}^{*}(5747)$ to be the $1P_{1}'$ and $1^{3}P_{2}$ assignments and the $B_{s1}(5830)$, $B_{s2}^{*}(5840)$ to be the strange partner of $B_{1}(5721)$ and $B_{2}^{*}(5747)$. Besides, we tentatively identify the recently observed $B_{J}(5840)$, $B_{J}(5970)$ as the $2^{3}S_{1}$ and $1^{3}D_{3}$ states, respectively. It is noticed that this conclusion needs further confirmation by measuring the decay channel to $B\pi$ of $B_{J}(5840)$ and $B_{J}(5970)$ in experiments.
hep-ph/9807333
N. B. Demchuk
N.B. Demchuk
Heavy quark limit in the light front quark model
14 pages, 1 figure
JHEP 9808:008,1998
10.1088/1126-6708/1998/08/008
PSU/TH/203
hep-ph
null
An explicit relativistic light-front model is presented which gives the momentum transfer dependent form factors of weak hadronic currents among heavy pseudoscalar and vector mesons in the whole accessible kinematical region $0\leq q^2 \leq q^2_{\max} $. It is shown that in the limit of infinite masses of active quarks these form factors can be expressed in terms of universal Isgur-Wise function. The explisit expression for this function is obtained. It is shown that neglecting of pair creation from the vacuum in calculations of form factors does not violate Luke's theorem.
[ { "created": "Fri, 10 Jul 1998 19:02:21 GMT", "version": "v1" }, { "created": "Fri, 11 Sep 1998 15:21:20 GMT", "version": "v2" } ]
2010-02-03
[ [ "Demchuk", "N. B.", "" ] ]
An explicit relativistic light-front model is presented which gives the momentum transfer dependent form factors of weak hadronic currents among heavy pseudoscalar and vector mesons in the whole accessible kinematical region $0\leq q^2 \leq q^2_{\max} $. It is shown that in the limit of infinite masses of active quarks these form factors can be expressed in terms of universal Isgur-Wise function. The explisit expression for this function is obtained. It is shown that neglecting of pair creation from the vacuum in calculations of form factors does not violate Luke's theorem.
1705.07935
Peter Athron
The GAMBIT Collaboration: Peter Athron, Csaba Bal\'azs, Torsten Bringmann, Andy Buckley, Marcin Chrz\k{a}szcz, Jan Conrad, Jonathan M. Cornell, Lars A. Dal, Joakim Edsj\"o, Ben Farmer, Paul Jackson, Abram Krislock, Anders Kvellestad, Farvah Mahmoudi, Gregory D. Martinez, Antje Putze, Are Raklev, Christopher Rogan, Roberto Ruiz de Austri, Aldo Saavedra, Christopher Savage, Pat Scott, Nicola Serra, Christoph Weniger, Martin White
Global fits of GUT-scale SUSY models with GAMBIT
50 pages, 21 figures, 7 tables, v2 accepted for publication in EPJC, v3 update Zenodo link
null
10.1140/epjc/s10052-017-5167-0
CoEPP-MN-17-9, gambit-physics-2017
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the most comprehensive global fits to date of three supersymmetric models motivated by grand unification: the Constrained Minimal Supersymmetric Standard Model (CMSSM), and its Non-Universal Higgs Mass generalisations NUHM1 and NUHM2. We include likelihoods from a number of direct and indirect dark matter searches, a large collection of electroweak precision and flavour observables, direct searches for supersymmetry at LEP and Runs I and II of the LHC, and constraints from Higgs observables. Our analysis improves on existing results not only in terms of the number of included observables, but also in the level of detail with which we treat them, our sampling techniques for scanning the parameter space, and our treatment of nuisance parameters. We show that stau co-annihilation is now ruled out in the CMSSM at more than 95\% confidence. Stop co-annihilation turns out to be one of the most promising mechanisms for achieving an appropriate relic density of dark matter in all three models, whilst avoiding all other constraints. We find high-likelihood regions of parameter space featuring light stops and charginos, making them potentially detectable in the near future at the LHC. We also show that tonne-scale direct detection will play a largely complementary role, probing large parts of the remaining viable parameter space, including essentially all models with multi-TeV neutralinos.
[ { "created": "Mon, 22 May 2017 18:22:56 GMT", "version": "v1" }, { "created": "Fri, 10 Nov 2017 06:54:35 GMT", "version": "v2" }, { "created": "Tue, 23 Oct 2018 07:38:35 GMT", "version": "v3" } ]
2020-08-06
[ [ "The GAMBIT Collaboration", "", "" ], [ "Athron", "Peter", "" ], [ "Balázs", "Csaba", "" ], [ "Bringmann", "Torsten", "" ], [ "Buckley", "Andy", "" ], [ "Chrząszcz", "Marcin", "" ], [ "Conrad", "Jan", "" ], [ "Cornell", "Jonathan M.", "" ], [ "Dal", "Lars A.", "" ], [ "Edsjö", "Joakim", "" ], [ "Farmer", "Ben", "" ], [ "Jackson", "Paul", "" ], [ "Krislock", "Abram", "" ], [ "Kvellestad", "Anders", "" ], [ "Mahmoudi", "Farvah", "" ], [ "Martinez", "Gregory D.", "" ], [ "Putze", "Antje", "" ], [ "Raklev", "Are", "" ], [ "Rogan", "Christopher", "" ], [ "de Austri", "Roberto Ruiz", "" ], [ "Saavedra", "Aldo", "" ], [ "Savage", "Christopher", "" ], [ "Scott", "Pat", "" ], [ "Serra", "Nicola", "" ], [ "Weniger", "Christoph", "" ], [ "White", "Martin", "" ] ]
We present the most comprehensive global fits to date of three supersymmetric models motivated by grand unification: the Constrained Minimal Supersymmetric Standard Model (CMSSM), and its Non-Universal Higgs Mass generalisations NUHM1 and NUHM2. We include likelihoods from a number of direct and indirect dark matter searches, a large collection of electroweak precision and flavour observables, direct searches for supersymmetry at LEP and Runs I and II of the LHC, and constraints from Higgs observables. Our analysis improves on existing results not only in terms of the number of included observables, but also in the level of detail with which we treat them, our sampling techniques for scanning the parameter space, and our treatment of nuisance parameters. We show that stau co-annihilation is now ruled out in the CMSSM at more than 95\% confidence. Stop co-annihilation turns out to be one of the most promising mechanisms for achieving an appropriate relic density of dark matter in all three models, whilst avoiding all other constraints. We find high-likelihood regions of parameter space featuring light stops and charginos, making them potentially detectable in the near future at the LHC. We also show that tonne-scale direct detection will play a largely complementary role, probing large parts of the remaining viable parameter space, including essentially all models with multi-TeV neutralinos.
hep-ph/9605233
Patricia Ball
Patricia Ball (CERN)
The Exclusive Decay $B\to\rho e \nu$ Beyond Model Calculations
6 pages + titlepage, latex2e, requires a4wide.sty and epsf.sty, 3 postscript figures included, Talk given at XXXIth Rencontres de Moriond, Electroweak Session, Les Arcs 1800 (France), March 96
null
null
null
hep-ph
null
Due to its comparatively theoretical ``simplicity'', the decay channel $B\to\rho e \nu$ offers one of the best possibilities to determine the CKM matrix element $|V_{ub}|$ accurately. I present a new calculation of the relevant hadronic form factors from light-cone sum rules. I also review the results from lattice calculations and find that they agree with the results from light-cone sum rules where comparison is possible.\\ This paper relies on work done in collaboration with V.M.\ Braun.
[ { "created": "Mon, 6 May 1996 22:54:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ball", "Patricia", "", "CERN" ] ]
Due to its comparatively theoretical ``simplicity'', the decay channel $B\to\rho e \nu$ offers one of the best possibilities to determine the CKM matrix element $|V_{ub}|$ accurately. I present a new calculation of the relevant hadronic form factors from light-cone sum rules. I also review the results from lattice calculations and find that they agree with the results from light-cone sum rules where comparison is possible.\\ This paper relies on work done in collaboration with V.M.\ Braun.
2003.04319
Peter Denton
Peter B. Denton
A Return To Neutrino Normalcy
5 pages, 2 figures, comments welcome; v2: 7 pages, 3 figures, discussion expanded
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Understanding the structure of the fermion mixing matrices is an important question in particle physics. The quark mixing matrix is approximately diagonal while the lepton mixing matrix has large off-diagonal elements. Attempting to understand these structures has been the focus of an large body of literature over the last several decades. In this article we propose a new set of conditions to test the structure of mass matrices called normalcy based on how close to diagonal the mixing matrix is. The mass ordering and the octant of $\theta_{23}$ represent two of these conditions. We point out that the quark matrix easily satisfies all six normalcy conditions while none of them are known to be fully satisfied for leptons at high significance. All of the conditions that can be tested for leptons suggest that the matrix could satisfy the normalcy conditions and upcoming experiments such as DUNE and T2HK will most likely determine if the lepton mass matrix satisfies all of them or not.
[ { "created": "Mon, 9 Mar 2020 18:00:00 GMT", "version": "v1" }, { "created": "Fri, 5 Feb 2021 23:39:50 GMT", "version": "v2" } ]
2021-02-09
[ [ "Denton", "Peter B.", "" ] ]
Understanding the structure of the fermion mixing matrices is an important question in particle physics. The quark mixing matrix is approximately diagonal while the lepton mixing matrix has large off-diagonal elements. Attempting to understand these structures has been the focus of an large body of literature over the last several decades. In this article we propose a new set of conditions to test the structure of mass matrices called normalcy based on how close to diagonal the mixing matrix is. The mass ordering and the octant of $\theta_{23}$ represent two of these conditions. We point out that the quark matrix easily satisfies all six normalcy conditions while none of them are known to be fully satisfied for leptons at high significance. All of the conditions that can be tested for leptons suggest that the matrix could satisfy the normalcy conditions and upcoming experiments such as DUNE and T2HK will most likely determine if the lepton mass matrix satisfies all of them or not.
2005.00552
Jaume Tarr\'us Castell\`a
Joan Soto and Jaume Tarr\'us Castell\`a
Nonrelativistic effective field theory for heavy exotic hadrons
14 pages, 1 figure. Journal version. Misprints corrected
Phys. Rev. D 102, 014012 (2020)
10.1103/PhysRevD.102.014012
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an effective field theory to describe hadrons with two heavy quarks without any assumption on the typical distance between the heavy quarks with respect to the typical hadronic scale. The construction is based on Non-Relativistic QCD and inspired in the strong coupling regime of Potential Non-Relativistic QCD. We construct the effective theory at leading and next-to-leading order in the inverse heavy-quark mass expansion for arbitrary quantum numbers of the light degrees of freedom. Hence our results hold for hybrids, tetraquarks, double heavy baryons and pentaquarks, for which we also present the corresponding operators at Non-Relativistic level. At leading order, the effective theory enjoys heavy quark spin symmetry and corresponds to the Born-Oppenheimer approximation. At next-to-leading order, spin and velocity dependent terms arise, which produce splittings in the heavy-quark spin symmetry multiplets. A concrete application to double heavy baryons is presented in an accompanying paper.
[ { "created": "Fri, 1 May 2020 18:02:07 GMT", "version": "v1" }, { "created": "Mon, 13 Jul 2020 10:55:48 GMT", "version": "v2" }, { "created": "Mon, 13 Sep 2021 13:58:57 GMT", "version": "v3" } ]
2021-09-14
[ [ "Soto", "Joan", "" ], [ "Castellà", "Jaume Tarrús", "" ] ]
We propose an effective field theory to describe hadrons with two heavy quarks without any assumption on the typical distance between the heavy quarks with respect to the typical hadronic scale. The construction is based on Non-Relativistic QCD and inspired in the strong coupling regime of Potential Non-Relativistic QCD. We construct the effective theory at leading and next-to-leading order in the inverse heavy-quark mass expansion for arbitrary quantum numbers of the light degrees of freedom. Hence our results hold for hybrids, tetraquarks, double heavy baryons and pentaquarks, for which we also present the corresponding operators at Non-Relativistic level. At leading order, the effective theory enjoys heavy quark spin symmetry and corresponds to the Born-Oppenheimer approximation. At next-to-leading order, spin and velocity dependent terms arise, which produce splittings in the heavy-quark spin symmetry multiplets. A concrete application to double heavy baryons is presented in an accompanying paper.
1711.09837
Eugenio Megias
Eugenio Megias, Enrique Ruiz Arriola, Lorenzo Luis Salcedo
Thermodynamic characterizations of exotic and missing states
3 pages, 2 figures. Presented by E.Megias at the XVII International Conference on Hadron Spectroscopy and Structure (Hadron 2017), 25-29 September 2017, Salamanca, Spain
null
null
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Thermal shifts and fluctuations at finite temperature below the deconfinement crossover of QCD from hadronic matter to the Quark-Gluon Plasma provide a viable way to look for exotic and missing states with given quantum numbers in the hadronic spectrum. We study a realization of the Hadron Resonance Gas model in the light quark ($uds$) flavor sector of QCD to study: i) the entropy shifts, and ii) the fluctuations of electric charge, baryon number and strangeness; and extract from them the possible existence of missing and exotic states from a comparison with lattice data. The analysis of the entropy shift based on the free energy of the Polyakov loop suggests the existence of exotic hybrids $g q \bar q$ and $gqqq$.
[ { "created": "Mon, 27 Nov 2017 17:14:58 GMT", "version": "v1" } ]
2017-11-28
[ [ "Megias", "Eugenio", "" ], [ "Arriola", "Enrique Ruiz", "" ], [ "Salcedo", "Lorenzo Luis", "" ] ]
Thermal shifts and fluctuations at finite temperature below the deconfinement crossover of QCD from hadronic matter to the Quark-Gluon Plasma provide a viable way to look for exotic and missing states with given quantum numbers in the hadronic spectrum. We study a realization of the Hadron Resonance Gas model in the light quark ($uds$) flavor sector of QCD to study: i) the entropy shifts, and ii) the fluctuations of electric charge, baryon number and strangeness; and extract from them the possible existence of missing and exotic states from a comparison with lattice data. The analysis of the entropy shift based on the free energy of the Polyakov loop suggests the existence of exotic hybrids $g q \bar q$ and $gqqq$.
1506.03786
Andrew Fowlie Dr.
Andrew Fowlie
The little-hierarchy problem is a little problem: understanding the difference between the big- and little-hierarchy problems with Bayesian probability
17 pages, 1 figure. Fixed typos, missing references, expanded a few points and added brief discussion of fine-tuning in frequentist statistics
null
null
null
hep-ph physics.hist-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experiments are once again under way at the LHC. This time around, however, the mood in the high-energy physics community is pessimistic. There is a growing suspicion that naturalness arguments that predict new physics near the weak scale are faulty and that prospects for a new discovery are limited. We argue that such doubts originate from a misunderstanding of the foundations of naturalness arguments. In spite of the first run at the LHC, which aggravated the little-hierarchy problem, there is no cause for doubting naturalness or natural theories. Naturalness is grounded in Bayesian probability logic - it is not a scientific theory and it makes no sense to claim that it could be falsified or that it is under pressure from experimental data. We should remain optimistic about discovery prospects; natural theories, such as supersymmetry, generally predict new physics close to the weak scale. Furthermore, from a Bayesian perspective, we briefly discuss 't Hooft's technical naturalness and a contentious claim that the little-hierarchy problem hints that the Standard Model is a fundamental theory.
[ { "created": "Thu, 11 Jun 2015 19:19:14 GMT", "version": "v1" }, { "created": "Mon, 6 Jul 2015 15:00:19 GMT", "version": "v2" } ]
2015-07-08
[ [ "Fowlie", "Andrew", "" ] ]
Experiments are once again under way at the LHC. This time around, however, the mood in the high-energy physics community is pessimistic. There is a growing suspicion that naturalness arguments that predict new physics near the weak scale are faulty and that prospects for a new discovery are limited. We argue that such doubts originate from a misunderstanding of the foundations of naturalness arguments. In spite of the first run at the LHC, which aggravated the little-hierarchy problem, there is no cause for doubting naturalness or natural theories. Naturalness is grounded in Bayesian probability logic - it is not a scientific theory and it makes no sense to claim that it could be falsified or that it is under pressure from experimental data. We should remain optimistic about discovery prospects; natural theories, such as supersymmetry, generally predict new physics close to the weak scale. Furthermore, from a Bayesian perspective, we briefly discuss 't Hooft's technical naturalness and a contentious claim that the little-hierarchy problem hints that the Standard Model is a fundamental theory.
1407.7995
Henryk Czyz
Henryk Czyz, Johann H. Kuhn, Szymon Tracz
Nucleon form factors and final state radiative corrections to $e^+e^-\to \bar p p \gamma$
the model of the form factors was improved
Phys. Rev. D 90, 114021 (2014)
10.1103/PhysRevD.90.114021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New parametrisation for the electric and the magnetic form factors of proton and neutron are presented. The proton form factors describe well the recent measurements by BaBar collaboration and earlier ones of the ratio of the form factors in space-like region. The neutron form factors are consistent with earlier measurements of neutron pair production and ratio of the form factors in the space-like region. These form factors are implemented into the generator PHOKHARA, which simulates the reactions $e^+e^-\to \bar p p \gamma$ and $e^+e^-\to \bar n n\gamma$. The influence of final state radiation is investigated.
[ { "created": "Wed, 30 Jul 2014 10:43:34 GMT", "version": "v1" }, { "created": "Wed, 19 Nov 2014 21:40:02 GMT", "version": "v2" } ]
2014-12-24
[ [ "Czyz", "Henryk", "" ], [ "Kuhn", "Johann H.", "" ], [ "Tracz", "Szymon", "" ] ]
New parametrisation for the electric and the magnetic form factors of proton and neutron are presented. The proton form factors describe well the recent measurements by BaBar collaboration and earlier ones of the ratio of the form factors in space-like region. The neutron form factors are consistent with earlier measurements of neutron pair production and ratio of the form factors in the space-like region. These form factors are implemented into the generator PHOKHARA, which simulates the reactions $e^+e^-\to \bar p p \gamma$ and $e^+e^-\to \bar n n\gamma$. The influence of final state radiation is investigated.
hep-ph/9704425
Tony Duncan
A. Duncan, Will Loinaz, and R.S. Willey (University of Pittsburgh)
Gauge Invariant Effective Potentials and Higgs Mass Bounds
30 pages (Latex) plus 5 embedded figures; minor corrections, one reference added
Phys. Rev. D 56, 3874 (1997)
10.1103/PhysRevD.56.3874
null
hep-ph
null
The problem of defining a gauge invariant effective potential with a strict energetic interpretation is examined in the context of spontaneously broken gauge theories. It is shown that such a potential can be defined in terms of a composite gauge invariant order parameter in physical gauges. This effective potential is computed through one loop order in a model with scalars and fermions coupled to an abelian gauge theory, which serves as a simple model of the situation in electroweak theory, where vacuum stability arguments based on the scalar effective potential have been used to place lower bounds on the Higgs mass.
[ { "created": "Mon, 28 Apr 1997 19:12:57 GMT", "version": "v1" }, { "created": "Mon, 12 May 1997 18:47:05 GMT", "version": "v2" } ]
2016-08-25
[ [ "Duncan", "A.", "", "University of Pittsburgh" ], [ "Loinaz", "Will", "", "University of Pittsburgh" ], [ "Willey", "R. S.", "", "University of Pittsburgh" ] ]
The problem of defining a gauge invariant effective potential with a strict energetic interpretation is examined in the context of spontaneously broken gauge theories. It is shown that such a potential can be defined in terms of a composite gauge invariant order parameter in physical gauges. This effective potential is computed through one loop order in a model with scalars and fermions coupled to an abelian gauge theory, which serves as a simple model of the situation in electroweak theory, where vacuum stability arguments based on the scalar effective potential have been used to place lower bounds on the Higgs mass.
hep-ph/0510211
Luca Haiberger
L. Haiberger, M. Weingran, H. Wenz, and S. Schiller
An experiment to detect gravity at sub-mm scale with high-Q mechanical oscillators
19 pages, to appear in Proceedings of the Tenth Marcel Grossmann Meeting on General Relativity, edited by M. Novello, S. Perez-Bergliaffa and R. Ruffini, World Scientific. Revision: portable format and revised figures
null
10.1142/9789812704030_0056
null
hep-ph
null
Silicon double paddle oscillators are well suited for the detection of weak forces because of their high Q factor (about 10^5 at room temperature). We describe an experiment aimed at the detection of gravitational forces between masses at sub-mm distance using such an oscillator. Gravitational excitation is produced by a rotating aluminium disk with platinum segments. The force sensitivity of this apparatus is about 10 fN at room temperature for 1000 s averaging time at room temperature. The current limitations to detection of the gravitational force are mentioned.
[ { "created": "Sun, 16 Oct 2005 11:08:51 GMT", "version": "v1" }, { "created": "Thu, 20 Oct 2005 21:38:36 GMT", "version": "v2" } ]
2016-11-09
[ [ "Haiberger", "L.", "" ], [ "Weingran", "M.", "" ], [ "Wenz", "H.", "" ], [ "Schiller", "S.", "" ] ]
Silicon double paddle oscillators are well suited for the detection of weak forces because of their high Q factor (about 10^5 at room temperature). We describe an experiment aimed at the detection of gravitational forces between masses at sub-mm distance using such an oscillator. Gravitational excitation is produced by a rotating aluminium disk with platinum segments. The force sensitivity of this apparatus is about 10 fN at room temperature for 1000 s averaging time at room temperature. The current limitations to detection of the gravitational force are mentioned.
1211.3352
Paulo Victor Recchia Gomes Silva
D. A. Fagundes, M. J. Menon, P. V. R. G. Silva
Reply to "Commentary on "Total Hadronic Cross Section Data and the Froissart-Martin Bound", by Fagundes, Menon and Silva"
16 pages, 1 figure, 2 tables, discussion extended and improved in sections III and IV (one paragraph reformulated after Eq. (2)), 5 references added and 3 updated, section III (Reply to Criticisms) and conclusions unchanged
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A reply to the above mentioned commentary by M.M. Block and F. Halzen on our quoted work is presented. We answer to each point raised by these authors and argument that our data reductions, strategies and methodology are adequate to the nonlinear-fit-problem in focus. In order to exemplify some arguments, additional information from our subsequent analysis is referred to. A brief commentary on the recent results by Block and Halzen is also presented. We understand that this reply gives support to the results and conclusions presented in our quoted work.
[ { "created": "Wed, 14 Nov 2012 16:31:48 GMT", "version": "v1" }, { "created": "Thu, 6 Dec 2012 13:10:41 GMT", "version": "v2" } ]
2012-12-07
[ [ "Fagundes", "D. A.", "" ], [ "Menon", "M. J.", "" ], [ "Silva", "P. V. R. G.", "" ] ]
A reply to the above mentioned commentary by M.M. Block and F. Halzen on our quoted work is presented. We answer to each point raised by these authors and argument that our data reductions, strategies and methodology are adequate to the nonlinear-fit-problem in focus. In order to exemplify some arguments, additional information from our subsequent analysis is referred to. A brief commentary on the recent results by Block and Halzen is also presented. We understand that this reply gives support to the results and conclusions presented in our quoted work.
0807.3758
Shmuel Nussinov
Frank T. Avignone III, Richard J Creswick, Shmuel Nussinov
Searching direction dependent daily modulation in dark matter detectors
12 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Channeling of recoil ions in various crystals strongly depends on their direction. This, along with the WIMP wind due to the rotation of the galactic disc generates {\it daily} modulations of the channeling. Since channeling affect the characteristics of the WIMP induced recoil events these modulations may be observed in single crystal detectors and serve as a WIMP signature. We suggest in particular searching for such modulations in the DAMA scintillation data.
[ { "created": "Wed, 23 Jul 2008 22:14:48 GMT", "version": "v1" } ]
2008-07-25
[ [ "Avignone", "Frank T.", "III" ], [ "Creswick", "Richard J", "" ], [ "Nussinov", "Shmuel", "" ] ]
Channeling of recoil ions in various crystals strongly depends on their direction. This, along with the WIMP wind due to the rotation of the galactic disc generates {\it daily} modulations of the channeling. Since channeling affect the characteristics of the WIMP induced recoil events these modulations may be observed in single crystal detectors and serve as a WIMP signature. We suggest in particular searching for such modulations in the DAMA scintillation data.
hep-ph/0207312
Paul Stoler
Paul Stoler
Baryon Form Factors at High Momentum Transfer and GPD's
null
null
10.1142/9789812776211_0037
null
hep-ph
null
Nucleon elastic and transition form factors at high momentum transfer -t are treated in terms of generalized parton distributions in a two-body framework. In this framework the high -t dependence of the form factors give information about the high k_perp, or short distance b_perp correlations of nucleon model wave functions. Applications are made to elastic and resonance nucleon form factors, and real Compton Scattering.
[ { "created": "Thu, 25 Jul 2002 15:57:13 GMT", "version": "v1" } ]
2017-08-23
[ [ "Stoler", "Paul", "" ] ]
Nucleon elastic and transition form factors at high momentum transfer -t are treated in terms of generalized parton distributions in a two-body framework. In this framework the high -t dependence of the form factors give information about the high k_perp, or short distance b_perp correlations of nucleon model wave functions. Applications are made to elastic and resonance nucleon form factors, and real Compton Scattering.
hep-ph/0411162
Yasuhiko Tsue
K.Watanabe, Y.Tsue, S.Nishiyama (Kochi Univ., Japan)
Amplification of Quantum Meson Modes in the Late Time of Chiral Phase Transition
17 pages, 16 figures
Prog.Theor.Phys. 113 (2005) 369-384
10.1143/PTP.113.369
null
hep-ph
null
It is shown that there exists a possibility of amplification of amplitudes of quantum pion modes with low momenta in the late time of chiral phase transition by using the Gaussian wave functional approximation in the O(4) linear sigma model. It is also shown that the amplification occurs in the mechanism of the resonance by forced oscillation as well as the parametric resonance induced by the small oscillation of the chiral condensate. These mechanisms are investigated in both the case of spatially homogeneous system and the spatially expanded system described by the Bjorken coordinate.
[ { "created": "Fri, 12 Nov 2004 06:53:32 GMT", "version": "v1" } ]
2009-11-10
[ [ "Watanabe", "K.", "", "Kochi Univ., Japan" ], [ "Tsue", "Y.", "", "Kochi Univ., Japan" ], [ "Nishiyama", "S.", "", "Kochi Univ., Japan" ] ]
It is shown that there exists a possibility of amplification of amplitudes of quantum pion modes with low momenta in the late time of chiral phase transition by using the Gaussian wave functional approximation in the O(4) linear sigma model. It is also shown that the amplification occurs in the mechanism of the resonance by forced oscillation as well as the parametric resonance induced by the small oscillation of the chiral condensate. These mechanisms are investigated in both the case of spatially homogeneous system and the spatially expanded system described by the Bjorken coordinate.
1505.04448
Raymundo Ramos
Christopher D. Carone, Raymundo Ramos
Dark chiral symmetry breaking and the origin of the electroweak scale
15 pages LaTeX, two pdf figures, to appear in Phys. Lett. B
null
10.1016/j.physletb.2015.05.044
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a classically scale-invariant model in which strong dynamics in a dark sector sets the scale of electroweak symmetry breaking. Our model is distinct from others of this type that have appeared in the recent literature. We show that the Higgs sector of the model is phenomenologically viable and that the spectrum of dark sector states includes a partially composite dark matter candidate.
[ { "created": "Sun, 17 May 2015 20:05:27 GMT", "version": "v1" } ]
2015-11-24
[ [ "Carone", "Christopher D.", "" ], [ "Ramos", "Raymundo", "" ] ]
We study a classically scale-invariant model in which strong dynamics in a dark sector sets the scale of electroweak symmetry breaking. Our model is distinct from others of this type that have appeared in the recent literature. We show that the Higgs sector of the model is phenomenologically viable and that the spectrum of dark sector states includes a partially composite dark matter candidate.
2005.11332
Lauri Niemi
Lauri Niemi, Michael J. Ramsey-Musolf, Tuomas V.I. Tenkanen, David J. Weir
Thermodynamics of a two-step electroweak phase transition
null
Phys. Rev. Lett. 126, 171802 (2021)
10.1103/PhysRevLett.126.171802
HIP-2020-11/TH, ACFI-T20-05
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New field content beyond that of the Standard Model of particle physics can alter the thermal history of electroweak symmetry breaking in the early universe. In particular, the symmetry breaking may have occurred through a sequence of successive phase transitions. We study the thermodynamics of such scenario in a real triplet extension of the Standard Model, using nonperturbative lattice simulations. Two-step electroweak phase transition is found to occur in a narrow region of allowed parameter space with the second transition always being first order. The first transition into the phase of non-vanishing triplet vacuum expectation value is first order in a non-negligible portion of the two-step parameter space. A comparison with 2-loop perturbative calculation is provided and significant discrepancies with the nonperturbative results are identified.
[ { "created": "Fri, 22 May 2020 18:00:11 GMT", "version": "v1" }, { "created": "Tue, 11 May 2021 12:05:21 GMT", "version": "v2" } ]
2021-05-12
[ [ "Niemi", "Lauri", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Tenkanen", "Tuomas V. I.", "" ], [ "Weir", "David J.", "" ] ]
New field content beyond that of the Standard Model of particle physics can alter the thermal history of electroweak symmetry breaking in the early universe. In particular, the symmetry breaking may have occurred through a sequence of successive phase transitions. We study the thermodynamics of such scenario in a real triplet extension of the Standard Model, using nonperturbative lattice simulations. Two-step electroweak phase transition is found to occur in a narrow region of allowed parameter space with the second transition always being first order. The first transition into the phase of non-vanishing triplet vacuum expectation value is first order in a non-negligible portion of the two-step parameter space. A comparison with 2-loop perturbative calculation is provided and significant discrepancies with the nonperturbative results are identified.
1007.0043
Michael Chanowitz
Michael S. Chanowitz
Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing
Adds discussion of alternative fourth family masses, including new best fit, and reconciles with published version
Phys. Rev. D:035018, 2010
10.1103/PhysRevD.82.035018
LBNL-3802E
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Limits on the Higgs boson mass restrict CKM mixing of a possible fourth family beyond the constraints previously obtained from precision electroweak data alone. Existing experimental and theoretical bounds on the Higgs mass already significantly restrict the allowed parameter space. Zero CKM mixing is excluded and mixing of order the Cabibbo angle is allowed. Upper and lower limits on 3-4 CKM mixing are exhibited as a function of the Higgs mass. We use the default inputs of the Electroweak Working Group and also explore the sensitivity of both the three and four family fits to alternative inputs.
[ { "created": "Wed, 30 Jun 2010 22:46:06 GMT", "version": "v1" }, { "created": "Fri, 27 Aug 2010 17:52:55 GMT", "version": "v2" } ]
2014-11-21
[ [ "Chanowitz", "Michael S.", "" ] ]
Limits on the Higgs boson mass restrict CKM mixing of a possible fourth family beyond the constraints previously obtained from precision electroweak data alone. Existing experimental and theoretical bounds on the Higgs mass already significantly restrict the allowed parameter space. Zero CKM mixing is excluded and mixing of order the Cabibbo angle is allowed. Upper and lower limits on 3-4 CKM mixing are exhibited as a function of the Higgs mass. We use the default inputs of the Electroweak Working Group and also explore the sensitivity of both the three and four family fits to alternative inputs.
1009.3557
Gi-Chol Cho
Yumiko Aida, Eri Asakawa, Gi-Chol Cho, Hikaru Matsuo (Ochanomizu University)
Leptonic decays of D_s and B^+ mesons in supersymmetric standard model with R-parity violating interactions
14 pages, 5 figures. Typos corrected. Version to appear in Phys.Rev.D
Phys.Rev.D82:115008,2010
10.1103/PhysRevD.82.115008
OCHA-PP-303
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate leptonic decays $D_s \to \tau \nu_\tau$ and $B^+ \to \tau \nu_\tau$ in R-parity violating (RPV) supersymmetric standard model. Taking account of interference between the s-channel slepton exchange and the $t$-channel squark exchange diagrams, we find that the supersymmetric contributions are cancelled between two diagrams so that the RPV couplings could be sizable under the experimental bounds. Constraints on the relative sign between the RPV couplings in $s$- and $t$-channel diagrams are also discussed.
[ { "created": "Sat, 18 Sep 2010 14:17:27 GMT", "version": "v1" }, { "created": "Tue, 2 Nov 2010 21:56:58 GMT", "version": "v2" } ]
2010-12-24
[ [ "Aida", "Yumiko", "", "Ochanomizu\n University" ], [ "Asakawa", "Eri", "", "Ochanomizu\n University" ], [ "Cho", "Gi-Chol", "", "Ochanomizu\n University" ], [ "Matsuo", "Hikaru", "", "Ochanomizu\n University" ] ]
We investigate leptonic decays $D_s \to \tau \nu_\tau$ and $B^+ \to \tau \nu_\tau$ in R-parity violating (RPV) supersymmetric standard model. Taking account of interference between the s-channel slepton exchange and the $t$-channel squark exchange diagrams, we find that the supersymmetric contributions are cancelled between two diagrams so that the RPV couplings could be sizable under the experimental bounds. Constraints on the relative sign between the RPV couplings in $s$- and $t$-channel diagrams are also discussed.
1704.03824
Seung-il Nam
Seung-il Nam
Quasi-distribution amplitudes for pion and kaon via the nonlocal chiral-quark model
12 pages, 8 figures, accepted for publication via Mod. Phys. Lett. A
Mod. Phys. Lett. A, Vol. 32, No. 39 (2017) 1750218
10.1142/S0217732317502182
PKNU-NuHaTh-2017-02
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the pseudoscalar (PS) meson ($\pi$ and $K$) quasi-distribution amplitude (QDA), which is supposed to be an asymptotic analog to the meson distribution amplitude (DA) $\phi_{\pi,K}(x)$ in the limit of the large longitudinal PS-meson momentum, i.e. $p_3\to\infty$, in the nonperturbative region. For this purpose, we employ the nonlocal chiral-quark model (NLChQM) in the light-front formalism with a minimal Fock-state for the mesons $\sim q\bar{q}$ at the low-energy scale parameter of the model $\Lambda\sim1$ GeV. As a trial, we extract the transverse-momentum distribution amplitude (TMDA) from the light-front wave function within the model, and convert it to QDA with help of the virtuality-distribution amplitude. By doing that, we derive an analytical expression for the nonperturbative QDA with the current-quark mass correction up to $\mathcal{O}(\Delta m_q)$. Numerically, we confirm that the obtained TMDA reproduces the experimental data for the photon-pion transition form factor $F_{\gamma\gamma^*\pi^0}(Q^2)$ at the low-$Q^2$ qualitatively well. We also observe that the obtained QDA approaches to DA as $p_3$ increases, showing the symmetric and asymmetric curves with respect to $x$ for the pion and kaon, respectively, due to the current-quark mass difference $m_{u,d}\ll m_s$. Assigning $\xi\equiv2x-1$, the moments $\langle\xi^n\rangle_{\pi,K}$ are computed, using the pion and kaon QDAs, and there appear only a few percent deviations in the moments for $p_3\gtrsim30\Lambda$ in comparison to the values calculated directly from DAs. It turns out that the higher moments are more sensitive to the change of $p_3$, whereas the lower ones depend less on it.
[ { "created": "Wed, 12 Apr 2017 16:34:03 GMT", "version": "v1" }, { "created": "Wed, 15 Nov 2017 12:47:13 GMT", "version": "v2" } ]
2017-12-20
[ [ "Nam", "Seung-il", "" ] ]
We investigate the pseudoscalar (PS) meson ($\pi$ and $K$) quasi-distribution amplitude (QDA), which is supposed to be an asymptotic analog to the meson distribution amplitude (DA) $\phi_{\pi,K}(x)$ in the limit of the large longitudinal PS-meson momentum, i.e. $p_3\to\infty$, in the nonperturbative region. For this purpose, we employ the nonlocal chiral-quark model (NLChQM) in the light-front formalism with a minimal Fock-state for the mesons $\sim q\bar{q}$ at the low-energy scale parameter of the model $\Lambda\sim1$ GeV. As a trial, we extract the transverse-momentum distribution amplitude (TMDA) from the light-front wave function within the model, and convert it to QDA with help of the virtuality-distribution amplitude. By doing that, we derive an analytical expression for the nonperturbative QDA with the current-quark mass correction up to $\mathcal{O}(\Delta m_q)$. Numerically, we confirm that the obtained TMDA reproduces the experimental data for the photon-pion transition form factor $F_{\gamma\gamma^*\pi^0}(Q^2)$ at the low-$Q^2$ qualitatively well. We also observe that the obtained QDA approaches to DA as $p_3$ increases, showing the symmetric and asymmetric curves with respect to $x$ for the pion and kaon, respectively, due to the current-quark mass difference $m_{u,d}\ll m_s$. Assigning $\xi\equiv2x-1$, the moments $\langle\xi^n\rangle_{\pi,K}$ are computed, using the pion and kaon QDAs, and there appear only a few percent deviations in the moments for $p_3\gtrsim30\Lambda$ in comparison to the values calculated directly from DAs. It turns out that the higher moments are more sensitive to the change of $p_3$, whereas the lower ones depend less on it.
1208.1444
Sergey Alekhin
S. Alekhin, J. Bluemlein, S.-O. Moch
ABM11 parton distributions and benchmarks
To appear in the proceedings of 20th International Workshop on Deep Inelastic Scattering and Related Subjects (DIS 2012), Bonn (Germany), 26-30 Mar 2012
null
null
DESY 12-139; LPN12-086; SFB/CPP-12-53
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a determination of the nucleon parton distribution functions (PDFs) and of the strong coupling constant $\alpha_s$ at next-to-next-to-leading order (NNLO) in QCD based on the world data for deep-inelastic scattering and the fixed-target data for the Drell-Yan process. The analysis is performed in the fixed-flavor number scheme for $n_f=3,4,5$ and uses the $\bar{MS}$ scheme for $\alpha_s$ and the heavy quark masses. The fit results are compared with other PDFs and used to compute the benchmark cross sections at hadron colliders to the NNLO accuracy.
[ { "created": "Tue, 7 Aug 2012 15:22:01 GMT", "version": "v1" } ]
2012-08-08
[ [ "Alekhin", "S.", "" ], [ "Bluemlein", "J.", "" ], [ "Moch", "S. -O.", "" ] ]
We present a determination of the nucleon parton distribution functions (PDFs) and of the strong coupling constant $\alpha_s$ at next-to-next-to-leading order (NNLO) in QCD based on the world data for deep-inelastic scattering and the fixed-target data for the Drell-Yan process. The analysis is performed in the fixed-flavor number scheme for $n_f=3,4,5$ and uses the $\bar{MS}$ scheme for $\alpha_s$ and the heavy quark masses. The fit results are compared with other PDFs and used to compute the benchmark cross sections at hadron colliders to the NNLO accuracy.
hep-ph/9710535
J.-Alexis Rodriguez L.
R. Diaz (1), R. Martinez (1) and J.-Alexis Rodriguez (1,2) ((1) Universidad Nacional de Colombia, (2) Centro Internacional de Fisica)
Compositeness and the asymmetries of leptons at the Z^0 peak
Latex, 13 pages, 4 figures
null
null
null
hep-ph
null
We study the effects on the leptonic asymmetries A_{FB}, A_{pol} and A_{LR} coming from a model of compositeness. We consider the effects coming from the self-energies and the vertex correction to $Z l^+ l^-$. Thus we use the Altarelli parametrization of the oblique corrections. We get the asymptotic limits of these corrections in terms of the parameters $(m^*, \Lambda, f, f')$ and we get bounds for the quotient $m^*/\Lambda$ with different values of $(f, f')$. We conclude that both asymmetries produce bounds for such quotient when $f'$ overweigth to $f$, and this fact is related with the breakdown of the custodial symmetry.
[ { "created": "Wed, 29 Oct 1997 23:13:34 GMT", "version": "v1" }, { "created": "Wed, 16 Sep 1998 23:49:40 GMT", "version": "v2" } ]
2007-05-23
[ [ "Diaz", "R.", "" ], [ "Martinez", "R.", "" ], [ "Rodriguez", "J. -Alexis", "" ] ]
We study the effects on the leptonic asymmetries A_{FB}, A_{pol} and A_{LR} coming from a model of compositeness. We consider the effects coming from the self-energies and the vertex correction to $Z l^+ l^-$. Thus we use the Altarelli parametrization of the oblique corrections. We get the asymptotic limits of these corrections in terms of the parameters $(m^*, \Lambda, f, f')$ and we get bounds for the quotient $m^*/\Lambda$ with different values of $(f, f')$. We conclude that both asymmetries produce bounds for such quotient when $f'$ overweigth to $f$, and this fact is related with the breakdown of the custodial symmetry.
hep-ph/0608044
Boris Kopeliovich
B.Z. Kopeliovich, J. Nemchik, Ivan Schmidt
Time Evolution of Jets and Perturbative Color Neutralization
Based on talk given by B.K. at the Fifth International Conference on Perspectives in Hadronic Physics, Trieste, May 2006
Nucl.Phys.A782:224-233,2007
10.1016/j.nuclphysa.2006.10.059
USM-TH-192
hep-ph
null
In-medium production of leading hadrons in hard reactions, carrying the main fraction of the jet momentum, involves two stages: (i) the parton originated from the hard process propagates through the medium radiating gluons due to the initial hard collision, as well as to multiple interactions in the medium; (ii) perturbative color neutralization, e.g. picking up an anti-colored parton produced perturbatively, followed by evolution and attenuation of the (pre)hadron in the medium. The color neutralization (or production) length for leading hadrons is controlled by coherence, energy conservation and Sudakov suppression. The pT-broadening is a sensitive and model independent probe for the production length. The color neutralization time is expected to shrink with rising hard scale. In particular, we found a very fast energy dissipation by a highly virtual parton: half of the jet energy is radiated during the first Fermi. Energy conservation makes the production of leading hadrons at longer times difficult.
[ { "created": "Fri, 4 Aug 2006 05:35:25 GMT", "version": "v1" } ]
2016-08-16
[ [ "Kopeliovich", "B. Z.", "" ], [ "Nemchik", "J.", "" ], [ "Schmidt", "Ivan", "" ] ]
In-medium production of leading hadrons in hard reactions, carrying the main fraction of the jet momentum, involves two stages: (i) the parton originated from the hard process propagates through the medium radiating gluons due to the initial hard collision, as well as to multiple interactions in the medium; (ii) perturbative color neutralization, e.g. picking up an anti-colored parton produced perturbatively, followed by evolution and attenuation of the (pre)hadron in the medium. The color neutralization (or production) length for leading hadrons is controlled by coherence, energy conservation and Sudakov suppression. The pT-broadening is a sensitive and model independent probe for the production length. The color neutralization time is expected to shrink with rising hard scale. In particular, we found a very fast energy dissipation by a highly virtual parton: half of the jet energy is radiated during the first Fermi. Energy conservation makes the production of leading hadrons at longer times difficult.
hep-ph/0412035
John F. Donoghue
John F. Donoghue, Barry R. Holstein, Tobias Huber and Andreas Ross
Long distance effects and strangeness in the nucleon
21 pages, 2 figures, to be published in a memorial volume for Dubravko Tadic in Fizika B
Fizika B14 (2005) 217-244
null
null
hep-ph
null
We discuss the calculation of the strange magnetic radius of the proton in chiral perturbation theory. In particular we investigate the low energy component of the loop integrals involving kaons. We separate the chiral calculation into a low energy part and a high energy component through use of a momentum space separation scale. This separation shows that most of the chiral calculation comes from high energies where the effective field theory treatment is not valid. The resulting low energy prediction is in better agreement with dispersive treatments. Finally, we briefly discuss magnetic moments and show how our techniques can help resolve an old puzzle in understanding the magnetic moments of the proton and Sigma^+.
[ { "created": "Thu, 2 Dec 2004 16:44:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Donoghue", "John F.", "" ], [ "Holstein", "Barry R.", "" ], [ "Huber", "Tobias", "" ], [ "Ross", "Andreas", "" ] ]
We discuss the calculation of the strange magnetic radius of the proton in chiral perturbation theory. In particular we investigate the low energy component of the loop integrals involving kaons. We separate the chiral calculation into a low energy part and a high energy component through use of a momentum space separation scale. This separation shows that most of the chiral calculation comes from high energies where the effective field theory treatment is not valid. The resulting low energy prediction is in better agreement with dispersive treatments. Finally, we briefly discuss magnetic moments and show how our techniques can help resolve an old puzzle in understanding the magnetic moments of the proton and Sigma^+.
2107.07487
Takashi Shimomura
Takeshi Araki, Kento Asai and Takashi Shimomura
Electron Beam Dump Constraints on Light Bosons with Lepton Flavor Violating Couplings
22 pages, 9 figures
null
10.1007/JHEP11(2021)082
UME-PP-019, STUPP-21-248, KYUSHU-HET-227
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study constraints on light and feebly interacting bosons with lepton flavor violation from electron beam dump experiments. Scalar, vector, and dipole interactions of the bosons are analyzed, respectively, and excluded regions from the searches for decays into electron-positron pairs are derived. It is found that parameter regions unconstrained by flavor violating decays of muon can be excluded using the results of the E137 experiment. We also discuss the impact of the search for flavor violating decays of the light bosons in electron beam dump experiments.
[ { "created": "Thu, 15 Jul 2021 17:40:49 GMT", "version": "v1" } ]
2021-12-01
[ [ "Araki", "Takeshi", "" ], [ "Asai", "Kento", "" ], [ "Shimomura", "Takashi", "" ] ]
We study constraints on light and feebly interacting bosons with lepton flavor violation from electron beam dump experiments. Scalar, vector, and dipole interactions of the bosons are analyzed, respectively, and excluded regions from the searches for decays into electron-positron pairs are derived. It is found that parameter regions unconstrained by flavor violating decays of muon can be excluded using the results of the E137 experiment. We also discuss the impact of the search for flavor violating decays of the light bosons in electron beam dump experiments.
1101.3592
Xing-Gang Wu
Tao Zhong, Xing-Gang Wu, Jia-Wei Zhang, Yun-Qing Tang and Zhen-Yun Fang
New results on Pionic Twist-3 Distribution Amplitudes within the QCD Sum Rules
9 pages, 6 figures and 6 tables. To be published in Phys.Rev.D
Phys.Rev.D83:036002,2011
10.1103/PhysRevD.83.036002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an improved calculation on the pionic twist-3 distribution amplitudes $\phi^{\pi}_{p}$ and $\phi^{\pi}_{\sigma}$, which are studied within the QCD sum rules. By adding all the uncertainties in quadrature, it is found that $<\xi^2_p>=0.248^{+0.076}_{-0.052}$, $<\xi^4_p>=0.262^{+0.080}_{-0.055}$, $<\xi^2_\sigma>=0.102^{+0.035}_{-0.025}$ and $<\xi^4_\sigma>=0.094^{+0.028}_{-0.020}$. Furthermore, with the help of these moments, we construct a model for the twist-3 wave functions $\psi^{\pi}_{p,\sigma}(x,\mathbf{k}_\bot)$, which have better end-point behavior and are helpful for perturbative QCD approach. The obtained twist-3 distribution amplitudes are adopted to calculate the $B\to\pi$ transition form factor $f^+_{B\pi}$ within the QCD light-cone sum rules up to next-to-leading order. By suitable choice of the parameters, we obtain a consistent $f^+_{B\pi}$ with those obtained in the literature.
[ { "created": "Wed, 19 Jan 2011 00:32:07 GMT", "version": "v1" } ]
2011-02-18
[ [ "Zhong", "Tao", "" ], [ "Wu", "Xing-Gang", "" ], [ "Zhang", "Jia-Wei", "" ], [ "Tang", "Yun-Qing", "" ], [ "Fang", "Zhen-Yun", "" ] ]
We present an improved calculation on the pionic twist-3 distribution amplitudes $\phi^{\pi}_{p}$ and $\phi^{\pi}_{\sigma}$, which are studied within the QCD sum rules. By adding all the uncertainties in quadrature, it is found that $<\xi^2_p>=0.248^{+0.076}_{-0.052}$, $<\xi^4_p>=0.262^{+0.080}_{-0.055}$, $<\xi^2_\sigma>=0.102^{+0.035}_{-0.025}$ and $<\xi^4_\sigma>=0.094^{+0.028}_{-0.020}$. Furthermore, with the help of these moments, we construct a model for the twist-3 wave functions $\psi^{\pi}_{p,\sigma}(x,\mathbf{k}_\bot)$, which have better end-point behavior and are helpful for perturbative QCD approach. The obtained twist-3 distribution amplitudes are adopted to calculate the $B\to\pi$ transition form factor $f^+_{B\pi}$ within the QCD light-cone sum rules up to next-to-leading order. By suitable choice of the parameters, we obtain a consistent $f^+_{B\pi}$ with those obtained in the literature.
1310.7487
David Weir
Anders Tranberg, David J. Weir
On the quantum stability of Q-balls
JHEP format, 17+1 pages, 9 figures; v2: improvements to several figures, text rewritten to improve legibility, conclusions unchanged, published in JHEP
JHEP 04(2014)184
10.1007/JHEP04(2014)184
HIP-2013-22/TH
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the evolution and decay of Q-balls under the influence of quantum fluctuations. We argue that the most important effect resulting from these fluctuations is the modification of the effective potential in which the Q-ball evolves. This is in addition to spontaneous decay into elementary particle excitations and fission into smaller Q-balls previously considered in the literature, which -- like most tunnelling processes -- are likely to be strongly suppressed. We illustrate the effect of quantum fluctuations in a particular model $\phi^6$ potential, for which we implement the inhomogeneous Hartree approximation to quantum dynamics and solve for the evolution of Q-balls in 3+1 dimensions. We find that the stability range as a function of (field space) angular velocity $\omega$ is modified significantly compared to the classical case, so that small-$\omega$ Q-balls are less stable than in the classical limit, and large-$\omega$ Q-balls are more stable. This can be understood qualitatively in a simple way.
[ { "created": "Mon, 28 Oct 2013 16:46:56 GMT", "version": "v1" }, { "created": "Mon, 5 May 2014 09:15:03 GMT", "version": "v2" } ]
2014-05-06
[ [ "Tranberg", "Anders", "" ], [ "Weir", "David J.", "" ] ]
We consider the evolution and decay of Q-balls under the influence of quantum fluctuations. We argue that the most important effect resulting from these fluctuations is the modification of the effective potential in which the Q-ball evolves. This is in addition to spontaneous decay into elementary particle excitations and fission into smaller Q-balls previously considered in the literature, which -- like most tunnelling processes -- are likely to be strongly suppressed. We illustrate the effect of quantum fluctuations in a particular model $\phi^6$ potential, for which we implement the inhomogeneous Hartree approximation to quantum dynamics and solve for the evolution of Q-balls in 3+1 dimensions. We find that the stability range as a function of (field space) angular velocity $\omega$ is modified significantly compared to the classical case, so that small-$\omega$ Q-balls are less stable than in the classical limit, and large-$\omega$ Q-balls are more stable. This can be understood qualitatively in a simple way.
1402.3409
Jeremiah Birrell
Jeremiah Birrell and Johann Rafelski
Proposal for Resonant Detection of Relic Massive Neutrinos
8 pages, 8 figures, to appear in European Physical Journal C
null
10.1140/epjc/s10052-015-3310-3
null
hep-ph astro-ph.CO nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel method for detecting the relic neutrino background that takes advantage of structured quantum degeneracy to amplify the drag force from neutrinos scattering off a detector. Developing this idea, we present a characterization of the present day relic neutrino distribution in an arbitrary frame, including the influence of neutrino mass and neutrino reheating by $e^+e^-$ annihilation. We present explicitly the neutrino velocity and de Broglie wavelength distributions for the case of an Earthbound observer. Considering that relic neutrinos could exhibit quantum liquid features at the present day temperature and density, we discuss the impact of neutrino fluid correlations on the possibility of resonant detection.
[ { "created": "Fri, 14 Feb 2014 09:41:19 GMT", "version": "v1" }, { "created": "Wed, 7 May 2014 06:14:45 GMT", "version": "v2" }, { "created": "Wed, 22 Oct 2014 19:56:46 GMT", "version": "v3" }, { "created": "Sun, 8 Feb 2015 23:49:36 GMT", "version": "v4" } ]
2015-06-18
[ [ "Birrell", "Jeremiah", "" ], [ "Rafelski", "Johann", "" ] ]
We present a novel method for detecting the relic neutrino background that takes advantage of structured quantum degeneracy to amplify the drag force from neutrinos scattering off a detector. Developing this idea, we present a characterization of the present day relic neutrino distribution in an arbitrary frame, including the influence of neutrino mass and neutrino reheating by $e^+e^-$ annihilation. We present explicitly the neutrino velocity and de Broglie wavelength distributions for the case of an Earthbound observer. Considering that relic neutrinos could exhibit quantum liquid features at the present day temperature and density, we discuss the impact of neutrino fluid correlations on the possibility of resonant detection.
2005.13063
Matthew Inglis-Whalen
Matthew Inglis-Whalen, Michael Luke, Aris Spourdalakis
Rapidity Logarithms in SCET Without Modes
14 pages, 4 figures; v2: wording changes, discussion of consistency constraints on rapidity anomalous dimensions added, double column formatting
null
10.1016/j.nuclphysa.2021.122260
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We re-examine observables with rapidity divergences in the context of a formulation of Soft-Collinear Effective Theory in which infrared degrees of freedom are not explicitly separated into modes. We consider the Sudakov form factor with a massive vector boson and Drell-Yan production of lepton pairs at small transverse momentum as demonstrative examples. In this formalism, rapidity divergences introduce a scheme dependence into the effective theory and are associated with large logarithms appearing in the soft matching conditions. This scheme dependence may be used to derive the corresponding rapidity renormalization group equations, and rates naturally factorize into hard, soft and jet contributions without the introduction of explicit modes.
[ { "created": "Tue, 26 May 2020 21:53:07 GMT", "version": "v1" }, { "created": "Wed, 19 May 2021 17:59:41 GMT", "version": "v2" } ]
2021-07-28
[ [ "Inglis-Whalen", "Matthew", "" ], [ "Luke", "Michael", "" ], [ "Spourdalakis", "Aris", "" ] ]
We re-examine observables with rapidity divergences in the context of a formulation of Soft-Collinear Effective Theory in which infrared degrees of freedom are not explicitly separated into modes. We consider the Sudakov form factor with a massive vector boson and Drell-Yan production of lepton pairs at small transverse momentum as demonstrative examples. In this formalism, rapidity divergences introduce a scheme dependence into the effective theory and are associated with large logarithms appearing in the soft matching conditions. This scheme dependence may be used to derive the corresponding rapidity renormalization group equations, and rates naturally factorize into hard, soft and jet contributions without the introduction of explicit modes.
hep-ph/0205282
David London
Alakabha Datta and David London
Measuring alpha using B -> K(*) Kbar(*) Decays
6 pages, LaTeX, no figures. Talk given by David London at Flavor Physics and CP Violation (FPCP), Philadelphia, PA, USA, May 2002
null
null
UdeM-GPP-TH-02-97
hep-ph
null
We describe a new method for obtaining the CP phase alpha via measurements of B_{d,s} -> K(*) Kbar(*) decays. This method is particularly appropriate for hadron colliders since some of the branching ratios are small [O(10^{-6})], and since B_s decays are involved. By comparing the value of alpha extracted from this method with that obtained in B -> pi pi or B -> rho pi decays, one can detect the presence of new physics in the b -> d penguin amplitude. The method does require theoretical input, but model calculations suggest that the theoretical uncertainty is at most 5%, and might well be even smaller. These estimates can be tested experimentally. The method is therefore quite clean.
[ { "created": "Fri, 24 May 2002 15:21:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Datta", "Alakabha", "" ], [ "London", "David", "" ] ]
We describe a new method for obtaining the CP phase alpha via measurements of B_{d,s} -> K(*) Kbar(*) decays. This method is particularly appropriate for hadron colliders since some of the branching ratios are small [O(10^{-6})], and since B_s decays are involved. By comparing the value of alpha extracted from this method with that obtained in B -> pi pi or B -> rho pi decays, one can detect the presence of new physics in the b -> d penguin amplitude. The method does require theoretical input, but model calculations suggest that the theoretical uncertainty is at most 5%, and might well be even smaller. These estimates can be tested experimentally. The method is therefore quite clean.
2408.05903
Jian-Wei Cui
Zhen-Yu Lei and Jian-Wei Cui
A minimal neutrino oscillation affected QCD axion model
8 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Combining the KSVZ axion model and the type-I seesaw mechanism, we construct a minimal axion model that may affect the phenomenon of neutrino oscillation. This minimal model requires flavor mixed axion-neutrinos interactions and two additional standard model (SM) singlet scalars which generate specific patterns of lepton mass matrices. These patterns yield a particular texture of Majorana neutrino mass matrix. We find that this texture, combined with existing neutrino experimental data, predicts an Inverted Hierarchy of neutrino masses with $17\lesssim m_1/m_3\lesssim 44$, and a hierarchy between the two VEVs of SM-singlet scalars. Finally, we examine the potential effect of this model on neutrino oscillation phenomena.
[ { "created": "Mon, 12 Aug 2024 03:12:45 GMT", "version": "v1" } ]
2024-08-13
[ [ "Lei", "Zhen-Yu", "" ], [ "Cui", "Jian-Wei", "" ] ]
Combining the KSVZ axion model and the type-I seesaw mechanism, we construct a minimal axion model that may affect the phenomenon of neutrino oscillation. This minimal model requires flavor mixed axion-neutrinos interactions and two additional standard model (SM) singlet scalars which generate specific patterns of lepton mass matrices. These patterns yield a particular texture of Majorana neutrino mass matrix. We find that this texture, combined with existing neutrino experimental data, predicts an Inverted Hierarchy of neutrino masses with $17\lesssim m_1/m_3\lesssim 44$, and a hierarchy between the two VEVs of SM-singlet scalars. Finally, we examine the potential effect of this model on neutrino oscillation phenomena.
2306.04127
Margarete Muhlleitner
Felix Egle, Margarete M\"uhlleitner, Rui Santos, Jo\~ao Viana
Electroweak Corrections to Higgs Boson Decays in a Complex Singlet Extension of the SM and their Phenomenological Impact
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The complex singlet extension CxSM of the Standard Model (SM) is a simple extension of the SM with two visible Higgs bosons in the spectrum and a Dark Matter (DM) candidate. In this paper we complete the computation of the next-to-leading (NLO) electroweak (EW) corrections to on-shell and non-loop-induced Higgs decays. Our calculations are implemented in the code EWsHDECAY which also includes the relevant QCD corrections. Performing an extensive parameter scan in the model and including all relevant theoretical and experimental single- and di-Higgs as well as DM constraints, we obtain a viable parameter sample. We find that current DM constraints are able to test the model in DM mass regions where collider searches are not sensitive. The relative EW corrections turn out to be large for scenarios with relatively large couplings, threshold effects or small leading-order (LO) widths. Otherwise, they are of typical EW size and can amount up to about 20-25%. The theory uncertainty derived from the change of the renormalization scheme dependence then is of a few per cent. While the NLO corrections applied in the constraints due to single- and di-Higgs searches impact the validity of specific parameter points, the overall shape of the allowed parameter region is not yet sensitive to the EW corrections. This picture will change with further increased experimental precision in the future and necessitates precise predictions on the theory side as presented in this paper.
[ { "created": "Wed, 7 Jun 2023 03:50:28 GMT", "version": "v1" } ]
2023-06-08
[ [ "Egle", "Felix", "" ], [ "Mühlleitner", "Margarete", "" ], [ "Santos", "Rui", "" ], [ "Viana", "João", "" ] ]
The complex singlet extension CxSM of the Standard Model (SM) is a simple extension of the SM with two visible Higgs bosons in the spectrum and a Dark Matter (DM) candidate. In this paper we complete the computation of the next-to-leading (NLO) electroweak (EW) corrections to on-shell and non-loop-induced Higgs decays. Our calculations are implemented in the code EWsHDECAY which also includes the relevant QCD corrections. Performing an extensive parameter scan in the model and including all relevant theoretical and experimental single- and di-Higgs as well as DM constraints, we obtain a viable parameter sample. We find that current DM constraints are able to test the model in DM mass regions where collider searches are not sensitive. The relative EW corrections turn out to be large for scenarios with relatively large couplings, threshold effects or small leading-order (LO) widths. Otherwise, they are of typical EW size and can amount up to about 20-25%. The theory uncertainty derived from the change of the renormalization scheme dependence then is of a few per cent. While the NLO corrections applied in the constraints due to single- and di-Higgs searches impact the validity of specific parameter points, the overall shape of the allowed parameter region is not yet sensitive to the EW corrections. This picture will change with further increased experimental precision in the future and necessitates precise predictions on the theory side as presented in this paper.
1204.6085
Jason Evans
Jason L. Evans, Masahiro Ibe and Tsutomu T. Yanagida
The Lightest Higgs Boson Mass in the MSSM with Strongly Interacting Spectators
31 pages, 13 figures
null
10.1103/PhysRevD.86.015017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new mechanism for producing a Higgs boson mass near 125 GeV within the MSSM. By coupling the MSSM Higgs boson to a set of strongly interacting fields, large corrections to the Higgs quartic coupling are induced. Although the Higgs doublets do not participate in the strong dynamics, they feel the effects of the strongly coupled sector via (semi-)perturbative interactions. These same strong dynamics are also capable of generating the $\mu$-term. Additionally, this strong sector is in the conformal window, which drives the couplings to an infrared fixed point and naturally generates model parameters of the appropriate size.
[ { "created": "Thu, 26 Apr 2012 23:46:49 GMT", "version": "v1" } ]
2013-05-30
[ [ "Evans", "Jason L.", "" ], [ "Ibe", "Masahiro", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
We propose a new mechanism for producing a Higgs boson mass near 125 GeV within the MSSM. By coupling the MSSM Higgs boson to a set of strongly interacting fields, large corrections to the Higgs quartic coupling are induced. Although the Higgs doublets do not participate in the strong dynamics, they feel the effects of the strongly coupled sector via (semi-)perturbative interactions. These same strong dynamics are also capable of generating the $\mu$-term. Additionally, this strong sector is in the conformal window, which drives the couplings to an infrared fixed point and naturally generates model parameters of the appropriate size.
1805.02441
Giorgio Torrieri
Melissa Mendes, Giorgio Torrieri
A quark-gluon plasma inspired model of the universe: Introduction and Inflation
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explain how a $SU(N_c)$ gauge theory, decoupled from the standard model and with a high-lying strong coupling scale, can incorporate apparently unrelated cosmological features, such as Inflation and dark matter, using well-understood dynamics from Quark-Gluon Plasma Physics. In our scenario, the evolution of the universe is throughoutly hot: Inflation occurs due to the bulk viscosity peak during the mixed phase to deconfinement, while dark matter is composed of weakly interacting glueballs formed in the same phase. We parametrize the temperature dependence of the EoS and the viscosity expected from gauge theory, solve the Friedmann-Robertson-Walker (FRW) equations and compute the number of efoldings as a function of the free parameters of the model.
[ { "created": "Mon, 7 May 2018 11:09:05 GMT", "version": "v1" } ]
2018-05-08
[ [ "Mendes", "Melissa", "" ], [ "Torrieri", "Giorgio", "" ] ]
We explain how a $SU(N_c)$ gauge theory, decoupled from the standard model and with a high-lying strong coupling scale, can incorporate apparently unrelated cosmological features, such as Inflation and dark matter, using well-understood dynamics from Quark-Gluon Plasma Physics. In our scenario, the evolution of the universe is throughoutly hot: Inflation occurs due to the bulk viscosity peak during the mixed phase to deconfinement, while dark matter is composed of weakly interacting glueballs formed in the same phase. We parametrize the temperature dependence of the EoS and the viscosity expected from gauge theory, solve the Friedmann-Robertson-Walker (FRW) equations and compute the number of efoldings as a function of the free parameters of the model.
2310.16353
Andr\'es G\'omez Arias
Gernot Eichmann, Andr\'es G\'omez, Jan Horak, Jan M. Pawlowski, Jonas Wessely, Nicolas Wink
Bound states from the spectral Bethe-Salpeter equation
15 pages, 16 figures
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the bound state properties of three-dimensional scalar $\phi^4$ theory in the broken phase. To this end, we extend the recently developed technique of spectral Dyson-Schwinger equations to solve the Bethe-Salpeter equation and determine the bound state spectrum. We employ consistent truncations for the two-, three- and four-point functions of the theory that recover the scaling properties in the infinite coupling limit. Our result for the mass of the lowest-lying bound state in this limit agrees very well with lattice determinations.
[ { "created": "Wed, 25 Oct 2023 04:31:02 GMT", "version": "v1" } ]
2023-10-26
[ [ "Eichmann", "Gernot", "" ], [ "Gómez", "Andrés", "" ], [ "Horak", "Jan", "" ], [ "Pawlowski", "Jan M.", "" ], [ "Wessely", "Jonas", "" ], [ "Wink", "Nicolas", "" ] ]
We compute the bound state properties of three-dimensional scalar $\phi^4$ theory in the broken phase. To this end, we extend the recently developed technique of spectral Dyson-Schwinger equations to solve the Bethe-Salpeter equation and determine the bound state spectrum. We employ consistent truncations for the two-, three- and four-point functions of the theory that recover the scaling properties in the infinite coupling limit. Our result for the mass of the lowest-lying bound state in this limit agrees very well with lattice determinations.
1309.1643
Alexander Bednyakov
A.V. Bednyakov, A.F. Pikelner, and V.N. Velizhanin
Three-loop beta-functions and anomalous dimensions in the Standard Model
8 pages, 5 figures, Talk presented at ACAT 2013. To be submitted to the proceedings of ACAT 2013
null
10.1088/1742-6596/523/1/012045
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk the methods and computer tools which were used in our recent calculation of the three-loop Standard Model renormalization group coefficients are discussed. A brief review of the techniques based on special features of dimensional regularization and minimal subtraction schemes is given. Our treatment of gamma5 is presented in some details. In addition, for a reasonable set of initial parameters the numerical estimates of the obtained three-loop contributions are presented.
[ { "created": "Fri, 6 Sep 2013 13:58:29 GMT", "version": "v1" } ]
2015-06-17
[ [ "Bednyakov", "A. V.", "" ], [ "Pikelner", "A. F.", "" ], [ "Velizhanin", "V. N.", "" ] ]
In this talk the methods and computer tools which were used in our recent calculation of the three-loop Standard Model renormalization group coefficients are discussed. A brief review of the techniques based on special features of dimensional regularization and minimal subtraction schemes is given. Our treatment of gamma5 is presented in some details. In addition, for a reasonable set of initial parameters the numerical estimates of the obtained three-loop contributions are presented.
2404.00690
James Cline
Gerald X. Gilbert-Thorple and J\^os\'e J. Jesus
Scatophobic Dark Matter
8 pages, 4 of which are references, two figures. v2: added references
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
An outstanding mystery of dark matter physics is the lack of direct detection signals to date. We suggest that dark matter is scatophobic: due to a repulsive long-range interaction, it is repelled by objects with a large net scat charge, such as the Earth, and is therefore not able to reach direct detection experiments. This represents the first step in a broader theoretical paradigm that we dub the "anti-anthropic principle."
[ { "created": "Sun, 31 Mar 2024 13:54:33 GMT", "version": "v1" }, { "created": "Sun, 7 Apr 2024 07:59:57 GMT", "version": "v2" } ]
2024-04-09
[ [ "Gilbert-Thorple", "Gerald X.", "" ], [ "Jesus", "Jôsé J.", "" ] ]
An outstanding mystery of dark matter physics is the lack of direct detection signals to date. We suggest that dark matter is scatophobic: due to a repulsive long-range interaction, it is repelled by objects with a large net scat charge, such as the Earth, and is therefore not able to reach direct detection experiments. This represents the first step in a broader theoretical paradigm that we dub the "anti-anthropic principle."
0807.0545
Cristian Pisano
C. Pisano, D. Boer and P.J. Mulders
T-odd Effects in Photon-Jet Production at the Tevatron
4 pages, 3 figures, to appear in the proceedings of 16th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2008), London, U.K., 7-11 Apr 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The angular distribution in photon-jet production in p\bar{p} -> \gamma jet X is studied within a generalized factorization scheme taking into account the transverse momentum of the partons in the initial hadrons. Within this scheme an anomalously large cos(2\phi) asymmetry observed in the Drell-Yan process could be attributed to the T-odd, spin and transverse momentum dependent parton distribution function h_1^{\perp q}(x, p_{\perp}^2). The same function is expected to produce a cos(2\phi) asymmetry in the photon-jet production cross section. This particular azimuthal asymmetry is estimated to be smaller than the Drell-Yan asymmetry but still of considerable size for Tevatron kinematics, offering a new possibility to study T-odd effects at the Tevatron.
[ { "created": "Thu, 3 Jul 2008 12:22:58 GMT", "version": "v1" } ]
2008-07-04
[ [ "Pisano", "C.", "" ], [ "Boer", "D.", "" ], [ "Mulders", "P. J.", "" ] ]
The angular distribution in photon-jet production in p\bar{p} -> \gamma jet X is studied within a generalized factorization scheme taking into account the transverse momentum of the partons in the initial hadrons. Within this scheme an anomalously large cos(2\phi) asymmetry observed in the Drell-Yan process could be attributed to the T-odd, spin and transverse momentum dependent parton distribution function h_1^{\perp q}(x, p_{\perp}^2). The same function is expected to produce a cos(2\phi) asymmetry in the photon-jet production cross section. This particular azimuthal asymmetry is estimated to be smaller than the Drell-Yan asymmetry but still of considerable size for Tevatron kinematics, offering a new possibility to study T-odd effects at the Tevatron.
1011.3082
Tracy Slatyer
Douglas P. Finkbeiner, Lisa Goodenough, Tracy R. Slatyer, Mark Vogelsberger, Neal Weiner
Consistent Scenarios for Cosmic-Ray Excesses from Sommerfeld-Enhanced Dark Matter Annihilation
Related web application at http://astrometry.fas.harvard.edu/mvogelsb/sommerfeld . v2: added brief clarification regarding propagation parameters, plots now show effect of relaxing CMB bounds. 35 pages in JCAP format, 4 figures. Accepted for publication in JCAP
JCAP 1105:002,2011
10.1088/1475-7516/2011/05/002
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Anomalies in direct and indirect detection have motivated models of dark matter consisting of a multiplet of nearly-degenerate states, coupled by a new GeV-scale interaction. We perform a careful analysis of the thermal freezeout of dark matter annihilation in such a scenario. We compute the range of "boost factors" arising from Sommerfeld enhancement in the local halo for models which produce the correct relic density, and show the effect of including constraints on the saturated enhancement from the cosmic microwave background (CMB). We find that boost factors from Sommerfeld enhancement of up to ~800 are possible in the local halo. When the CMB bounds on the saturated enhancement are applied, the maximal boost factor is reduced to ~400 for 1-2 TeV dark matter and sub-GeV force carriers, but remains large enough to explain the observed Fermi and PAMELA electronic signals. We describe regions in the DM mass-boost factor plane where the cosmic ray data is well fit for a range of final states, and show that Sommerfeld enhancement alone is enough to provide the large annihilation cross sections required to fit the data, although for light mediator masses (less than ~200 MeV) there is tension with the CMB constraints in the absence of astrophysical boost factors from substructure. Additionally, we consider the circumstances under which WIMPonium formation is relevant and find for heavy WIMPs (greater than ~2 TeV) and soft-spectrum annihilation channels it can be an important consideration; we find regions with dark matter mass greater than 2.8 TeV that are consistent with the CMB bounds and have ~600-700 present-day boost factors.
[ { "created": "Sat, 13 Nov 2010 00:57:28 GMT", "version": "v1" }, { "created": "Tue, 12 Apr 2011 16:13:30 GMT", "version": "v2" } ]
2015-03-17
[ [ "Finkbeiner", "Douglas P.", "" ], [ "Goodenough", "Lisa", "" ], [ "Slatyer", "Tracy R.", "" ], [ "Vogelsberger", "Mark", "" ], [ "Weiner", "Neal", "" ] ]
Anomalies in direct and indirect detection have motivated models of dark matter consisting of a multiplet of nearly-degenerate states, coupled by a new GeV-scale interaction. We perform a careful analysis of the thermal freezeout of dark matter annihilation in such a scenario. We compute the range of "boost factors" arising from Sommerfeld enhancement in the local halo for models which produce the correct relic density, and show the effect of including constraints on the saturated enhancement from the cosmic microwave background (CMB). We find that boost factors from Sommerfeld enhancement of up to ~800 are possible in the local halo. When the CMB bounds on the saturated enhancement are applied, the maximal boost factor is reduced to ~400 for 1-2 TeV dark matter and sub-GeV force carriers, but remains large enough to explain the observed Fermi and PAMELA electronic signals. We describe regions in the DM mass-boost factor plane where the cosmic ray data is well fit for a range of final states, and show that Sommerfeld enhancement alone is enough to provide the large annihilation cross sections required to fit the data, although for light mediator masses (less than ~200 MeV) there is tension with the CMB constraints in the absence of astrophysical boost factors from substructure. Additionally, we consider the circumstances under which WIMPonium formation is relevant and find for heavy WIMPs (greater than ~2 TeV) and soft-spectrum annihilation channels it can be an important consideration; we find regions with dark matter mass greater than 2.8 TeV that are consistent with the CMB bounds and have ~600-700 present-day boost factors.
hep-ph/0507142
Ryo Takahasi
Ryo Takahashi and Morimitsu Tanimoto
Model of Mass Varying Neutrinos in SUSY
references are added, to be published in Physics Letters B
Phys.Lett. B633 (2006) 675-680
10.1016/j.physletb.2005.11.017
null
hep-ph
null
We discuss the mass varying neutrino scenario in the supersymmetric theory. In the case of the model with the single superfield, one needs the soft SUSY breaking terms or the $\mu$ term. However, fine-tunings of some parameters are required to be consistent with the cosmological data. In order to avoid the fine-tuning, we discuss the model with two superfields, which is consistent with the cosmological data. However, it is found that the left-handed neutrino mixes with the neutrino of the dark sector maximally. Adding a right- handed neutrino, which does not couple to the dark sector, we obtain a favorable model in the phenomenology of the neutrino experiments. In this model, the deceleration of the cosmological expansion converts to the acceleration near $z\simeq 0.5$. The speed of sound $c_s$ becomes imaginary if we put $\omega_0=-0.9$, which corresponds to $m_\nu^0=3.17\eV$. On the other hand, if we take $\omega_0=-0.998$, which leads to $m_\nu^0=0.05\eV$, $c_s^2$ becomes positive since $\omega$ evolves rapidly near the present epoch in our model.
[ { "created": "Tue, 12 Jul 2005 11:20:34 GMT", "version": "v1" }, { "created": "Thu, 14 Jul 2005 06:07:53 GMT", "version": "v2" }, { "created": "Tue, 19 Jul 2005 03:48:29 GMT", "version": "v3" }, { "created": "Thu, 21 Jul 2005 05:22:08 GMT", "version": "v4" }, { "created": "Fri, 28 Oct 2005 05:58:51 GMT", "version": "v5" }, { "created": "Tue, 1 Nov 2005 10:29:13 GMT", "version": "v6" }, { "created": "Thu, 10 Nov 2005 05:20:42 GMT", "version": "v7" } ]
2009-11-11
[ [ "Takahashi", "Ryo", "" ], [ "Tanimoto", "Morimitsu", "" ] ]
We discuss the mass varying neutrino scenario in the supersymmetric theory. In the case of the model with the single superfield, one needs the soft SUSY breaking terms or the $\mu$ term. However, fine-tunings of some parameters are required to be consistent with the cosmological data. In order to avoid the fine-tuning, we discuss the model with two superfields, which is consistent with the cosmological data. However, it is found that the left-handed neutrino mixes with the neutrino of the dark sector maximally. Adding a right- handed neutrino, which does not couple to the dark sector, we obtain a favorable model in the phenomenology of the neutrino experiments. In this model, the deceleration of the cosmological expansion converts to the acceleration near $z\simeq 0.5$. The speed of sound $c_s$ becomes imaginary if we put $\omega_0=-0.9$, which corresponds to $m_\nu^0=3.17\eV$. On the other hand, if we take $\omega_0=-0.998$, which leads to $m_\nu^0=0.05\eV$, $c_s^2$ becomes positive since $\omega$ evolves rapidly near the present epoch in our model.
hep-ph/9902213
Domenec Espriu
D.Espriu
QCD
Talk delivered at the XXVI International Meeting on Fundamental Physics. La Toja, June 1998. 26 pages. 9 figures. LaTeX, uses epsfig
null
null
UB-ECM-PF-99/03
hep-ph
null
This is the written version of the lecture on deep inelastic scattering and related topics in QCD, delivered in the course of the XXVI International Meeting on Fundamental Physics to an audience of young experimentalists. The aim is fundamentally pedagogical. I review the theoretical setting of the Altarelli-Parisi equations, discuss recent determinations of $\alpha_s$ from deep-inelastic scattering and then move to the kinematical region explored by HERA. In the way I mention some unsolved theoretical problems. I discuss low-x physics and to what extent $\log{1/x}$ resummations are called for.
[ { "created": "Mon, 1 Feb 1999 14:05:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Espriu", "D.", "" ] ]
This is the written version of the lecture on deep inelastic scattering and related topics in QCD, delivered in the course of the XXVI International Meeting on Fundamental Physics to an audience of young experimentalists. The aim is fundamentally pedagogical. I review the theoretical setting of the Altarelli-Parisi equations, discuss recent determinations of $\alpha_s$ from deep-inelastic scattering and then move to the kinematical region explored by HERA. In the way I mention some unsolved theoretical problems. I discuss low-x physics and to what extent $\log{1/x}$ resummations are called for.
2307.05450
Valery Lyubovitskij
Valery E. Lyubovitskij, Ivan Schmidt
Bulk-to-boundary propagators with arbitrary total angular momentum $J$ in soft-wall AdS/QCD
12 pages, 3 figures
Phys. Rev. D 108, 054030 (2023)
10.1103/PhysRevD.108.054030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the equations of motion for the bulk-to-boundary propagators of the anti-de Sitter (AdS) boson and fermion fields with arbitrary total angular momentum $J$, in a soft-wall AdS/QCD model and solve it analytically. It provides the opportunity to study transition form factors induced by these bulk-to-boundary propagators, both for on-shell and off-shell hadrons. This is a continuation of our study of hadron form factors induced by the bulk-to-boundary propagator with total angular momentum $J=1$ (e.g., electromagnetic form factors of mesons, nucleons, and nucleon resonances).
[ { "created": "Tue, 11 Jul 2023 17:26:08 GMT", "version": "v1" }, { "created": "Mon, 25 Sep 2023 14:37:31 GMT", "version": "v2" } ]
2023-09-26
[ [ "Lyubovitskij", "Valery E.", "" ], [ "Schmidt", "Ivan", "" ] ]
We derive the equations of motion for the bulk-to-boundary propagators of the anti-de Sitter (AdS) boson and fermion fields with arbitrary total angular momentum $J$, in a soft-wall AdS/QCD model and solve it analytically. It provides the opportunity to study transition form factors induced by these bulk-to-boundary propagators, both for on-shell and off-shell hadrons. This is a continuation of our study of hadron form factors induced by the bulk-to-boundary propagator with total angular momentum $J=1$ (e.g., electromagnetic form factors of mesons, nucleons, and nucleon resonances).
1810.06122
Martin Kirakosyan
Martin Kirakosyan, Aleksandr Kovalenko, Andrey Leonidov
Sound propagation and Mach cone in anisotropic hydrodynamics
9 pages, 4 figures
null
10.1140/epjc/s10052-019-6919-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This letter is based on a kinetic theory approach to anisotropic hydrodynamics. We derive the sound wave equation in anisotropic hydrodynamics and show that a corresponding wave front is ellipsoidal. The phenomenon of Mach cone emission in anisotropic hydrodynamics is studied. It is shown that Mach cone in anisotropic case becomes asymmetric, i. e. in this limit they're two different angles, left and right with respect to the ultrasonic particle direction, which are determined by the direction of ultrasonic particle propagation and the asymmetry coefficient.
[ { "created": "Sun, 14 Oct 2018 22:54:32 GMT", "version": "v1" }, { "created": "Tue, 12 Feb 2019 21:16:27 GMT", "version": "v2" } ]
2019-06-26
[ [ "Kirakosyan", "Martin", "" ], [ "Kovalenko", "Aleksandr", "" ], [ "Leonidov", "Andrey", "" ] ]
This letter is based on a kinetic theory approach to anisotropic hydrodynamics. We derive the sound wave equation in anisotropic hydrodynamics and show that a corresponding wave front is ellipsoidal. The phenomenon of Mach cone emission in anisotropic hydrodynamics is studied. It is shown that Mach cone in anisotropic case becomes asymmetric, i. e. in this limit they're two different angles, left and right with respect to the ultrasonic particle direction, which are determined by the direction of ultrasonic particle propagation and the asymmetry coefficient.
2304.04931
Giang Bui Thi Ha
Bui Thi Ha Giang, Dang Van Soa, Le Mai Dung
Investigation of the scalar unparticle and anomalous couplings at muon colliders in final states with multiple photons in the Randall- Sundrum model
13 figures, 2 tables. arXiv admin note: text overlap with arXiv:1807.00457
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The influence of the scalar unparticle and anomalous couplings at muon colliders in final states with multiple photons in the Randall-Sundrum model is evaluated in detail. The results indicate that with fixed collision energies, the total cross-sections for the production of multiple photons depend strongly on the polarization of the muon beams, the parameters of unparticle physics (the scaling dimension $d_{U}$, operator $\mathcal{O}_{U}$, the energy scale $\Lambda_{U}$) and also the strength of anomalous couplings. Numerical evaluation shows that the cross-sections for the production of four photons in finale states with the contribution of scalar anomalous couplings are much larger than that of the unparticle under the same conditions. In the Higgs-radion mixing, the cross sections achieve the maximum value at the radion-dominated state, $m_{\phi} = 125$ GeV, in which the cross-section is much enhanced and can be measurable in current experiments.
[ { "created": "Tue, 11 Apr 2023 02:06:44 GMT", "version": "v1" }, { "created": "Wed, 13 Mar 2024 14:29:32 GMT", "version": "v2" } ]
2024-03-14
[ [ "Giang", "Bui Thi Ha", "" ], [ "Van Soa", "Dang", "" ], [ "Dung", "Le Mai", "" ] ]
The influence of the scalar unparticle and anomalous couplings at muon colliders in final states with multiple photons in the Randall-Sundrum model is evaluated in detail. The results indicate that with fixed collision energies, the total cross-sections for the production of multiple photons depend strongly on the polarization of the muon beams, the parameters of unparticle physics (the scaling dimension $d_{U}$, operator $\mathcal{O}_{U}$, the energy scale $\Lambda_{U}$) and also the strength of anomalous couplings. Numerical evaluation shows that the cross-sections for the production of four photons in finale states with the contribution of scalar anomalous couplings are much larger than that of the unparticle under the same conditions. In the Higgs-radion mixing, the cross sections achieve the maximum value at the radion-dominated state, $m_{\phi} = 125$ GeV, in which the cross-section is much enhanced and can be measurable in current experiments.
hep-ph/9804375
Holger Gies
Walter Dittrich, Holger Gies (Tubingen U.)
Light propagation in non-trivial QED vacua
13 pages, REVTeX, 3 figures, to appear in Phys. Rev. D
Phys.Rev. D58 (1998) 025004
10.1103/PhysRevD.58.025004
UNITU-DITT-2-1998
hep-ph hep-th
null
Within the framework of effective action QED, we derive the light cone condition for homogeneous non-trivial QED vacua in the geometric optics approximation. Our result generalizes the ``unified formula'' suggested by Latorre, Pascual and Tarrach and allows for the calculation of velocity shifts and refractive indices for soft photons travelling through these vacua. Furthermore, we clarify the connection between the light velocity shift and the scale anomaly. This study motivates the introduction of a so-called effective action charge that characterizes the velocity modifying properties of the vacuum. Several applications are given concerning vacuum modifications caused by, e.g., strong fields, Casimir systems and high temperature.
[ { "created": "Thu, 23 Apr 1998 15:53:56 GMT", "version": "v1" } ]
2009-10-31
[ [ "Dittrich", "Walter", "", "Tubingen U." ], [ "Gies", "Holger", "", "Tubingen U." ] ]
Within the framework of effective action QED, we derive the light cone condition for homogeneous non-trivial QED vacua in the geometric optics approximation. Our result generalizes the ``unified formula'' suggested by Latorre, Pascual and Tarrach and allows for the calculation of velocity shifts and refractive indices for soft photons travelling through these vacua. Furthermore, we clarify the connection between the light velocity shift and the scale anomaly. This study motivates the introduction of a so-called effective action charge that characterizes the velocity modifying properties of the vacuum. Several applications are given concerning vacuum modifications caused by, e.g., strong fields, Casimir systems and high temperature.
1011.2310
Tzu Chiang Yuan
Kingman Cheung, Po-Yan Tseng and Tzu-Chiang Yuan
Cosmic Antiproton Constraints on Effective Interactions of the Dark Matter
19 pages, 4 figures, 2 tables
JCAP 1101:004,2011
10.1088/1475-7516/2011/01/004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using an effective interaction approach to describe the interactions between the dark matter particle and the light degrees of freedom of the standard model, we calculate the antiproton flux due to the annihilation of the dark matter in the Galactic Halo and compare to the most recent antiproton spectrum of the PAMELA experiment. We obtain useful constraints on the size of the effective interactions that are comparable to those deduced from collider and gamma-ray experiments.
[ { "created": "Wed, 10 Nov 2010 08:34:15 GMT", "version": "v1" } ]
2011-05-13
[ [ "Cheung", "Kingman", "" ], [ "Tseng", "Po-Yan", "" ], [ "Yuan", "Tzu-Chiang", "" ] ]
Using an effective interaction approach to describe the interactions between the dark matter particle and the light degrees of freedom of the standard model, we calculate the antiproton flux due to the annihilation of the dark matter in the Galactic Halo and compare to the most recent antiproton spectrum of the PAMELA experiment. We obtain useful constraints on the size of the effective interactions that are comparable to those deduced from collider and gamma-ray experiments.
1609.09078
Bhubanjyoti Bhattacharya
Bhubanjyoti Bhattacharya, Alakabha Datta, Jean-Pascal Gu\'evin, David London, and Ryoutaro Watanabe
Simultaneous Explanation of the $R_K$ and $R_{D^{(*)}}$ Puzzles: a Model Analysis
33 pages, 4 figures; Version 3: Mistakes in code corrected, leading to modified results: VB model now just barely viable. Still, principal conclusions of the paper remain largely unchanged
J. High Energ. Phys. (2017) 2017: 15
10.1007/JHEP01(2017)015
UdeM-GPP-TH-16-252; UMISS-HEP-2016-02; UH-511-1265-2016; CTPU-16-28; WSU-HEP-1605
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
$R_K$ and $R_{D^{(*)}}$ are two $B$-decay measurements that presently exhibit discrepancies with the SM. Recently, using an effective field theory approach, it was demonstrated that a new-physics model can simultaneously explain both the $R_K$ and $R_{D^{(*)}}$ puzzles. There are two UV completions that can give rise to the effective Lagrangian: (i) $VB$: a vector boson that transforms as an $SU(2)_L$ triplet, as in the SM, (ii) $U_1$: an $SU(2)_L$-singlet vector leptoquark. In this paper, we examine these models individually. A key point is that $VB$ contributes to $B^0_s$-${\bar B}^0_s$ mixing and $\tau \to 3\mu$, while $U_1$ does not. We show that, when constraints from these processes are taken into account, the $VB$ model is just barely viable. It predicts ${\cal B} (\tau^-\to\mu^-\mu^+\mu^-) \simeq 2.1 \times 10^{-8}$. This is measurable at Belle II and LHCb, and therefore constitutes a smoking-gun signal of $VB$. For $U_1$, there are several observables that may point to this model. Perhaps the most interesting is the lepton-flavor-violating decay $\Upsilon(3S) \to \mu \tau$, which has previously been overlooked in the literature. $U_1$ predicts ${\cal B}(\Upsilon(3S) \to \mu \tau)|_{\rm max} = 8.0 \times 10^{-7}$. Thus, if a large value of ${\cal B}(\Upsilon(3S) \to \mu \tau)$ is observed -- and this should be measurable at Belle II -- the $U_1$ model would be indicated.
[ { "created": "Wed, 28 Sep 2016 20:00:02 GMT", "version": "v1" }, { "created": "Thu, 6 Oct 2016 19:39:25 GMT", "version": "v2" }, { "created": "Tue, 6 Dec 2016 20:56:07 GMT", "version": "v3" } ]
2017-01-10
[ [ "Bhattacharya", "Bhubanjyoti", "" ], [ "Datta", "Alakabha", "" ], [ "Guévin", "Jean-Pascal", "" ], [ "London", "David", "" ], [ "Watanabe", "Ryoutaro", "" ] ]
$R_K$ and $R_{D^{(*)}}$ are two $B$-decay measurements that presently exhibit discrepancies with the SM. Recently, using an effective field theory approach, it was demonstrated that a new-physics model can simultaneously explain both the $R_K$ and $R_{D^{(*)}}$ puzzles. There are two UV completions that can give rise to the effective Lagrangian: (i) $VB$: a vector boson that transforms as an $SU(2)_L$ triplet, as in the SM, (ii) $U_1$: an $SU(2)_L$-singlet vector leptoquark. In this paper, we examine these models individually. A key point is that $VB$ contributes to $B^0_s$-${\bar B}^0_s$ mixing and $\tau \to 3\mu$, while $U_1$ does not. We show that, when constraints from these processes are taken into account, the $VB$ model is just barely viable. It predicts ${\cal B} (\tau^-\to\mu^-\mu^+\mu^-) \simeq 2.1 \times 10^{-8}$. This is measurable at Belle II and LHCb, and therefore constitutes a smoking-gun signal of $VB$. For $U_1$, there are several observables that may point to this model. Perhaps the most interesting is the lepton-flavor-violating decay $\Upsilon(3S) \to \mu \tau$, which has previously been overlooked in the literature. $U_1$ predicts ${\cal B}(\Upsilon(3S) \to \mu \tau)|_{\rm max} = 8.0 \times 10^{-7}$. Thus, if a large value of ${\cal B}(\Upsilon(3S) \to \mu \tau)$ is observed -- and this should be measurable at Belle II -- the $U_1$ model would be indicated.
2301.01739
Tobias Hurth
Tobias Hurth and Robert Szafron
Refactorisation in subleading $\bar B \to X_s \gamma$
24 pages, 4 figures
null
10.1016/j.nuclphysb.2023.116200
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We establish refactorisation conditions between the subleading ${O}_8$-${O}_8$ contributions to the inclusive $\bar B \to X_s \gamma$ decay suffering from endpoint divergences and prove a factorisation theorem for these contributions to all orders in the strong coupling constant. This allows for higher-order calculations of the resolved contributions and consistent summation of large logarithms, consequently reducing the recently found large-scale dependence in these contributions. We implement the concept of refactorisation in a heavy flavour application of SCET, which includes nonperturbative functions as additional subtlety not present in collider applications.
[ { "created": "Wed, 4 Jan 2023 18:12:40 GMT", "version": "v1" } ]
2023-05-17
[ [ "Hurth", "Tobias", "" ], [ "Szafron", "Robert", "" ] ]
We establish refactorisation conditions between the subleading ${O}_8$-${O}_8$ contributions to the inclusive $\bar B \to X_s \gamma$ decay suffering from endpoint divergences and prove a factorisation theorem for these contributions to all orders in the strong coupling constant. This allows for higher-order calculations of the resolved contributions and consistent summation of large logarithms, consequently reducing the recently found large-scale dependence in these contributions. We implement the concept of refactorisation in a heavy flavour application of SCET, which includes nonperturbative functions as additional subtlety not present in collider applications.
hep-ph/9810482
Dan Pirjol
Michael Gronau, Dan Pirjol and Tung-Mow Yan
Model-independent electroweak penguins in B decays to two pseudoscalars
17 pages ReVTeX with one included eps figure
Phys.Rev.D60:034021,1999; Erratum-ibid.D69:119901,2004
10.1103/PhysRevD.60.034021 10.1103/PhysRevD.69.119901
CLNS 98/1582, TECHNION-PH-98-88
hep-ph
null
We study the effects of electroweak penguin (EWP) amplitudes in $B$ meson decays into two charmless pseudoscalars in the approximation of retaining only the dominant EWP operators $Q_9$ and $Q_{10}$. Using flavor SU(3) symmetry, we derive a set of model-independent relations between EWP contributions and tree-level decay amplitudes one of which was noted recently by Neubert and Rosner. Two new applications of these relations are demonstrated in which uncertainties due to EWP corrections are eliminated in order to determine a weak phase. Whereas the weak angle $\alpha$ can be obtained from $B\to\pi\pi$ free of hadronic uncertainties, a determination of $\gamma$ from $B^{0,\pm}\to K\pi^{\pm}$ requires the knowledge of a ratio of certain tree-level hadronic matrix elements. The smallness of this ratio implies a useful constraint on $\gamma$ if rescattering can be neglected.
[ { "created": "Mon, 26 Oct 1998 14:34:15 GMT", "version": "v1" } ]
2014-11-17
[ [ "Gronau", "Michael", "" ], [ "Pirjol", "Dan", "" ], [ "Yan", "Tung-Mow", "" ] ]
We study the effects of electroweak penguin (EWP) amplitudes in $B$ meson decays into two charmless pseudoscalars in the approximation of retaining only the dominant EWP operators $Q_9$ and $Q_{10}$. Using flavor SU(3) symmetry, we derive a set of model-independent relations between EWP contributions and tree-level decay amplitudes one of which was noted recently by Neubert and Rosner. Two new applications of these relations are demonstrated in which uncertainties due to EWP corrections are eliminated in order to determine a weak phase. Whereas the weak angle $\alpha$ can be obtained from $B\to\pi\pi$ free of hadronic uncertainties, a determination of $\gamma$ from $B^{0,\pm}\to K\pi^{\pm}$ requires the knowledge of a ratio of certain tree-level hadronic matrix elements. The smallness of this ratio implies a useful constraint on $\gamma$ if rescattering can be neglected.
hep-ph/0510121
Paul Romatschke
Paul Romatschke and Raju Venugopalan
Collective non-Abelian instabilities in a melting Color Glass Condensate
4 pages, 4 figures, revtex4; v2: typos corrected, discussion on growth rate in expanding system added, accepted for publication in PRL
Phys.Rev.Lett.96:062302,2006
10.1103/PhysRevLett.96.062302
BI-TP 2005/43
hep-ph hep-lat nucl-th
null
We present first results for 3+1-D simulations of SU(2) Yang-Mills equations for matter expanding into the vacuum after a heavy ion collision. Violations of boost invariance cause a Weibel instability leading soft modes to grow with proper time $\tau$ as $\exp(\Gamma \sqrt{g^2\mu \tau})$, where $g^2\mu$ is a scale arising from the saturation of gluons in the nuclear wavefunction. The scale for the growth rate $\Gamma$ is set by a plasmon mass, defined as $\omega_{\rm pl}= \kappa_0 \sqrt{\frac{g^2\mu}{\tau}}$, generated dynamically in the collision. We compare the numerical ratio $\Gamma/\kappa_0$ to the corresponding value predicted by the Hard Thermal Loop formalism for anisotropic plasmas.
[ { "created": "Mon, 10 Oct 2005 19:26:20 GMT", "version": "v1" }, { "created": "Thu, 19 Jan 2006 09:20:28 GMT", "version": "v2" } ]
2010-04-06
[ [ "Romatschke", "Paul", "" ], [ "Venugopalan", "Raju", "" ] ]
We present first results for 3+1-D simulations of SU(2) Yang-Mills equations for matter expanding into the vacuum after a heavy ion collision. Violations of boost invariance cause a Weibel instability leading soft modes to grow with proper time $\tau$ as $\exp(\Gamma \sqrt{g^2\mu \tau})$, where $g^2\mu$ is a scale arising from the saturation of gluons in the nuclear wavefunction. The scale for the growth rate $\Gamma$ is set by a plasmon mass, defined as $\omega_{\rm pl}= \kappa_0 \sqrt{\frac{g^2\mu}{\tau}}$, generated dynamically in the collision. We compare the numerical ratio $\Gamma/\kappa_0$ to the corresponding value predicted by the Hard Thermal Loop formalism for anisotropic plasmas.
0812.4136
Rumin Wang
C. S. Kim, Ru-Min Wang and Ya-Dong Yang
Studying Double Charm Decays of B_{u,d} and B_{s} Mesons in the MSSM with R-parity Violation
28 pages and 6 figures, matches published version
Phys.Rev.D79:055004,2009
10.1103/PhysRevD.79.055004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the possible large direct CP asymmetry of \bar{B}^0_d \to D^+ D^- decay measured by Belle collaboration, we investigate double charm B_{u,d} and B_s decays in the minimal supersymmetric standard model with R-parity violation. We derive the bounds on relevant R-parity violating couplings from the current experimental data, which show quite consistent measurements among relative collaborations. Using the constrained parameter spaces, we explore R-parity violating effects on other observables in these decays, which have not been measured or have not been well measured yet. We find that the R-parity violating effects on the mixing-induced CP asymmetries of \bar{B}^0_d \to D^{(*)+} D^{(*)-} and \bar{B}^0_s \to D^{(*)+}_s D^{(*)-}_s decays could be very large, nevertheless the R-parity violating effects on the direct CP asymmetries could not be large enough to explain the large direct CP violation of \bar{B}^0_d \to D^{+} D^{-} from Belle. Our results could be used to probe R-parity violating effects and will correlate with searches for direct R-parity violating signals in future experiments.
[ { "created": "Mon, 22 Dec 2008 09:36:35 GMT", "version": "v1" }, { "created": "Mon, 2 Mar 2009 13:05:08 GMT", "version": "v2" }, { "created": "Mon, 9 Mar 2009 14:18:43 GMT", "version": "v3" } ]
2009-11-19
[ [ "Kim", "C. S.", "" ], [ "Wang", "Ru-Min", "" ], [ "Yang", "Ya-Dong", "" ] ]
Motivated by the possible large direct CP asymmetry of \bar{B}^0_d \to D^+ D^- decay measured by Belle collaboration, we investigate double charm B_{u,d} and B_s decays in the minimal supersymmetric standard model with R-parity violation. We derive the bounds on relevant R-parity violating couplings from the current experimental data, which show quite consistent measurements among relative collaborations. Using the constrained parameter spaces, we explore R-parity violating effects on other observables in these decays, which have not been measured or have not been well measured yet. We find that the R-parity violating effects on the mixing-induced CP asymmetries of \bar{B}^0_d \to D^{(*)+} D^{(*)-} and \bar{B}^0_s \to D^{(*)+}_s D^{(*)-}_s decays could be very large, nevertheless the R-parity violating effects on the direct CP asymmetries could not be large enough to explain the large direct CP violation of \bar{B}^0_d \to D^{+} D^{-} from Belle. Our results could be used to probe R-parity violating effects and will correlate with searches for direct R-parity violating signals in future experiments.
0807.4923
Tatsuru Kikuchi
Tatsuru Kikuchi and Takayuki Kubo
B-L assisted Anomaly Mediation and the radiative B-L symmetry breaking
20 pages, 7 figures; version to appear in Phys. Lett. B
Phys.Lett.B669:81-87,2008
10.1016/j.physletb.2008.09.040
KEK-TH-1265
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Anomaly mediated supersymmetry breaking implemented in the minimal supersymmetric standard model (MSSM) is known to suffer from the tachyonic slepton problem leading to breakdown of electric charge conservation. We show however that when MSSM is extended to explain small neutrino masses by gauging the B-L symmetry, the slepton masses can be positive due to the Z' mediation contributions. We obtain various soft supersymmetry breaking mass spectra, which are different from those obtained in the conventional anomaly mediation scenario. Then there would be a distinct signature of this scenario at the LHC.
[ { "created": "Wed, 30 Jul 2008 19:13:20 GMT", "version": "v1" }, { "created": "Thu, 31 Jul 2008 19:22:58 GMT", "version": "v2" }, { "created": "Tue, 23 Sep 2008 15:45:57 GMT", "version": "v3" } ]
2008-11-26
[ [ "Kikuchi", "Tatsuru", "" ], [ "Kubo", "Takayuki", "" ] ]
Anomaly mediated supersymmetry breaking implemented in the minimal supersymmetric standard model (MSSM) is known to suffer from the tachyonic slepton problem leading to breakdown of electric charge conservation. We show however that when MSSM is extended to explain small neutrino masses by gauging the B-L symmetry, the slepton masses can be positive due to the Z' mediation contributions. We obtain various soft supersymmetry breaking mass spectra, which are different from those obtained in the conventional anomaly mediation scenario. Then there would be a distinct signature of this scenario at the LHC.
1705.10366
Tobias Hurth
Michael Benzke, Tobias Hurth, and Sascha Turczyk
Subleading Power Factorization in $\bar B \to X_s \ell^+\ell^-$
32 pages,18 figures
null
10.1007/JHEP10(2017)031
MITP/17-019
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the factorization to subleading power in the flavor changing neutral current process $\bar B\to X_s \ell^+ \ell^-$. In particular, we compute the so-called resolved contributions and explore the numerical impact on observables. In these contributions the virtual photon couples to light partons instead of connecting directly to the effective weak-interaction vertex. They represent an irreducible uncertainty in the inclusive $\bar B \to X_s \ell^+ \ell^-$ decay which cannot be removed by relaxing the experimentally necessary cuts in the hadronic mass spectrum.
[ { "created": "Mon, 29 May 2017 19:12:12 GMT", "version": "v1" } ]
2017-10-25
[ [ "Benzke", "Michael", "" ], [ "Hurth", "Tobias", "" ], [ "Turczyk", "Sascha", "" ] ]
We analyze the factorization to subleading power in the flavor changing neutral current process $\bar B\to X_s \ell^+ \ell^-$. In particular, we compute the so-called resolved contributions and explore the numerical impact on observables. In these contributions the virtual photon couples to light partons instead of connecting directly to the effective weak-interaction vertex. They represent an irreducible uncertainty in the inclusive $\bar B \to X_s \ell^+ \ell^-$ decay which cannot be removed by relaxing the experimentally necessary cuts in the hadronic mass spectrum.
1710.02149
Satyanarayan Mukhopadhyay
Dorival Goncalves, Tao Han, Satyanarayan Mukhopadhyay
Off-shell Higgs Probe to Naturalness
5 pages, 4 figures; v2: results for 27 TeV LHC upgrade included and scale dependence of couplings specified; v3: revised figures, main conclusions unchanged
Phys. Rev. Lett. 120, 111801 (2018)
10.1103/PhysRevLett.120.111801
PITT-PACC-1711
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Examining the Higgs sector at high energy scales through off-shell Higgs production can potentially shed light on the naturalness problem of the Higgs mass. We propose such a study at the LHC by utilizing a representative model with a new scalar field ($S$) coupled to the Standard Model Higgs doublet ($H$) in a form $ |S|^2 |H|^2$. In the process $p p \rightarrow h^* \rightarrow ZZ$, the dominant momentum-dependent part of the one-loop scalar singlet corrections, especially above the new threshold at $2m_S$, leads to a measurable deviation in the differential distribution of the $Z$-pair invariant mass, in accordance with the quadratic divergence cancellation to the Higgs mass. We find that it is conceivable to probe such new physics at the $5\sigma$ level at the high-luminosity LHC, improving further with the upgraded $27$ TeV LHC, without requiring the precise measurement of the Higgs boson total width. The discovery of such a Higgs portal could also have important implications for thermal dark matter as well as for electroweak baryogenesis.
[ { "created": "Thu, 5 Oct 2017 18:00:02 GMT", "version": "v1" }, { "created": "Mon, 23 Oct 2017 20:17:24 GMT", "version": "v2" }, { "created": "Tue, 3 Jul 2018 17:45:28 GMT", "version": "v3" } ]
2018-07-04
[ [ "Goncalves", "Dorival", "" ], [ "Han", "Tao", "" ], [ "Mukhopadhyay", "Satyanarayan", "" ] ]
Examining the Higgs sector at high energy scales through off-shell Higgs production can potentially shed light on the naturalness problem of the Higgs mass. We propose such a study at the LHC by utilizing a representative model with a new scalar field ($S$) coupled to the Standard Model Higgs doublet ($H$) in a form $ |S|^2 |H|^2$. In the process $p p \rightarrow h^* \rightarrow ZZ$, the dominant momentum-dependent part of the one-loop scalar singlet corrections, especially above the new threshold at $2m_S$, leads to a measurable deviation in the differential distribution of the $Z$-pair invariant mass, in accordance with the quadratic divergence cancellation to the Higgs mass. We find that it is conceivable to probe such new physics at the $5\sigma$ level at the high-luminosity LHC, improving further with the upgraded $27$ TeV LHC, without requiring the precise measurement of the Higgs boson total width. The discovery of such a Higgs portal could also have important implications for thermal dark matter as well as for electroweak baryogenesis.
0710.3925
Begum Umme Jamil
U. Jamil and J. K. Sarma
Regge behaviour of structure functions and solution of Dokshitzer-Gribov-Lipatov-Altarelli-Parisi Evolution equations in next-to-leading order at low-x
15 pages, 4 figures
null
null
null
hep-ph
null
Deuteron and proton structure functions are derived from Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations of singlet and non-singlet structure functions in next-to-leading order (NLO) at low-x assuming the Regge behaviour of singlet and non-singlet structure functions at this limit and results are compared with New Muon Collaboration (NMC) and E665 collaboration data sets.
[ { "created": "Sun, 21 Oct 2007 12:03:19 GMT", "version": "v1" } ]
2007-10-23
[ [ "Jamil", "U.", "" ], [ "Sarma", "J. K.", "" ] ]
Deuteron and proton structure functions are derived from Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations of singlet and non-singlet structure functions in next-to-leading order (NLO) at low-x assuming the Regge behaviour of singlet and non-singlet structure functions at this limit and results are compared with New Muon Collaboration (NMC) and E665 collaboration data sets.
1804.05066
Jessica Turner
K. Moffat, S. Pascoli, S.T. Petcov, H. Schulz, J. Turner
Three-Flavoured Non-Resonant Leptogenesis at Intermediate Scales
29 pages, 13 figures, minor text modification consistent with version accepted in PRD
Phys. Rev. D 98, 015036 (2018)
10.1103/PhysRevD.98.015036
IPPP/18/25, FERMILAB-PUB-18-100-T, IPMU18-0062, SISSA 17/2018/FISI
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Leptogenesis can successfully explain the matter-antimatter asymmetry via out-of-equilibrium decays of heavy Majorana neutrinos in the early Universe. In this article, we focus on non-resonant thermal leptogenesis and the possibility of lowering its scale. In order to do so, we calculate the lepton asymmetry produced from the decays of one and two heavy Majorana neutrinos using three-flavoured density matrix equations in an exhaustive exploration of the model parameter space. We find regions of the parameter space where thermal leptogenesis is viable at intermediate scales, $T\sim 10^{6}$ GeV. However, the viability of thermal leptogenesis at such scales requires a certain degree of cancellation between the tree and one-loop level contribution to the light neutrino mass matrix and we quantify such fine-tuning.
[ { "created": "Fri, 13 Apr 2018 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 4 Sep 2018 22:36:17 GMT", "version": "v2" } ]
2018-09-06
[ [ "Moffat", "K.", "" ], [ "Pascoli", "S.", "" ], [ "Petcov", "S. T.", "" ], [ "Schulz", "H.", "" ], [ "Turner", "J.", "" ] ]
Leptogenesis can successfully explain the matter-antimatter asymmetry via out-of-equilibrium decays of heavy Majorana neutrinos in the early Universe. In this article, we focus on non-resonant thermal leptogenesis and the possibility of lowering its scale. In order to do so, we calculate the lepton asymmetry produced from the decays of one and two heavy Majorana neutrinos using three-flavoured density matrix equations in an exhaustive exploration of the model parameter space. We find regions of the parameter space where thermal leptogenesis is viable at intermediate scales, $T\sim 10^{6}$ GeV. However, the viability of thermal leptogenesis at such scales requires a certain degree of cancellation between the tree and one-loop level contribution to the light neutrino mass matrix and we quantify such fine-tuning.
1503.00156
Daniel Boyanovsky
D. Boyanovsky
Effective Field Theory out of Equilibrium: Brownian quantum fields
33 pages 4 figs, typos fixed, refs.updated, published version
New J. Phys. 17 (2015) 063017
10.1088/1367-2630/17/6/063017
null
hep-ph cond-mat.stat-mech hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The emergence of an effective field theory out of equilibrium is studied in the case in which a light field --the system-- interacts with very heavy fields in a finite temperature bath. We obtain the reduced density matrix for the light field, its time evolution is determined by an effective action that includes the \emph{influence action} from correlations of the heavy degrees of freedom. The non-equilibrium effective field theory yields a Langevin equation of motion for the light field in terms of dissipative and noise kernels that obey a generalized fluctuation dissipation relation. These are completely determined by the spectral density of the bath which is analyzed in detail for several cases. At $T=0$ we elucidate the effect of thresholds in the renormalization aspects and the asymptotic emergence of a local effective field theory with unitary time evolution. At $T\neq 0$ new "anomalous" thresholds arise, in particular the \emph{decay} of the environmental heavy fields into the light field leads to \emph{dissipative} dynamics of the light field. Even when the heavy bath particles are thermally suppressed this dissipative contribution leads to the \emph{thermalization} of the light field which is confirmed by a quantum kinetics analysis. We obtain the quantum master equation and show explicitly that its solution in the field basis is precisely the influence action that determines the effective non-equilibrium field theory. The Lindblad form of the quantum master equation features \emph{time dependent dissipative coefficients}. Their time dependence is crucial to extract renormalization effects at asymptotically long time. The dynamics from the quantum master equation is in complete agreement with that of the effective action, Langevin dynamics and quantum kinetics, thus providing a unified framework to effective field theory out of equilibrium.
[ { "created": "Sat, 28 Feb 2015 16:50:15 GMT", "version": "v1" }, { "created": "Fri, 19 Jun 2015 19:41:02 GMT", "version": "v2" } ]
2015-06-22
[ [ "Boyanovsky", "D.", "" ] ]
The emergence of an effective field theory out of equilibrium is studied in the case in which a light field --the system-- interacts with very heavy fields in a finite temperature bath. We obtain the reduced density matrix for the light field, its time evolution is determined by an effective action that includes the \emph{influence action} from correlations of the heavy degrees of freedom. The non-equilibrium effective field theory yields a Langevin equation of motion for the light field in terms of dissipative and noise kernels that obey a generalized fluctuation dissipation relation. These are completely determined by the spectral density of the bath which is analyzed in detail for several cases. At $T=0$ we elucidate the effect of thresholds in the renormalization aspects and the asymptotic emergence of a local effective field theory with unitary time evolution. At $T\neq 0$ new "anomalous" thresholds arise, in particular the \emph{decay} of the environmental heavy fields into the light field leads to \emph{dissipative} dynamics of the light field. Even when the heavy bath particles are thermally suppressed this dissipative contribution leads to the \emph{thermalization} of the light field which is confirmed by a quantum kinetics analysis. We obtain the quantum master equation and show explicitly that its solution in the field basis is precisely the influence action that determines the effective non-equilibrium field theory. The Lindblad form of the quantum master equation features \emph{time dependent dissipative coefficients}. Their time dependence is crucial to extract renormalization effects at asymptotically long time. The dynamics from the quantum master equation is in complete agreement with that of the effective action, Langevin dynamics and quantum kinetics, thus providing a unified framework to effective field theory out of equilibrium.
1408.4820
Andrzej Buras
Andrzej J. Buras
$\Delta I=1/2$ Rule and $\hat B_K$ : 2014
References, two plots and additional comments on the LHC bounds added, conclusions unchanged: 11 pages, 3 Figures, invited talk presented at QCD@Work 2014, Giovinazzo (Bari,Italy) June 16-19, 2014. To be published by EPJ Web of Conferences
null
null
FLAVOUR(267104)-ERC-82
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I summarize the status of the $\Delta I=1/2$ rule in $K\to\pi\pi$ decays within an {\it analytic} approach based on the dual representation of QCD as a theory of weakly interacting mesons for large $N$, where $N$ is the number of colours. This approximate approach, developed in the 1980s by William Bardeen, Jean-Marc G\'erard and myself, allowed us already 28 years ago to identify the dominant dynamics behind the $\Delta I=1/2$ rule. However, the recent inclusion of lowest-lying vector meson contributions in addition to the pseudoscalar ones to hadronic matrix elements of current-current operators and the calculation of the corresponding Wilson coefficients in a momentum scheme at the NLO improved significantly the matching between quark-gluon short distance contributions and meson long distance contributions over our results in 1986. We obtain satisfactory description of the ${\rm Re}A_2$ amplitude and ${\rm Re}A_0/{\rm Re}A_2=16.0\pm 1.5$ to be compared with its experimental value of $22.3$. While this difference could be the result of present theoretical uncertainties in our approach, it cannot be excluded that New Physics (NP) is here at work. The analysis by Fulvia De Fazio, Jennifer Girrbach-Noe and myself shows that indeed a tree-level $Z^\prime$ or $G^\prime$ exchanges with masses in the reach of the LHC and special couplings to quarks can significantly improve the theoretical status of the $\Delta I=1/2$ rule. I stress that our approach allows to understand the physics behind recent numerical results obtained in lattice QCD not only for the $\Delta I=1/2$ rule but also for the parameter $\hat B_K$ that enters the evaluation of $\varepsilon_K$. In contrast to the $\Delta I=1/2$ rule the chapter on $\hat B_K$ in QCD appears to be basically closed.
[ { "created": "Wed, 20 Aug 2014 21:14:31 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 2014 08:16:00 GMT", "version": "v2" } ]
2014-10-08
[ [ "Buras", "Andrzej J.", "" ] ]
I summarize the status of the $\Delta I=1/2$ rule in $K\to\pi\pi$ decays within an {\it analytic} approach based on the dual representation of QCD as a theory of weakly interacting mesons for large $N$, where $N$ is the number of colours. This approximate approach, developed in the 1980s by William Bardeen, Jean-Marc G\'erard and myself, allowed us already 28 years ago to identify the dominant dynamics behind the $\Delta I=1/2$ rule. However, the recent inclusion of lowest-lying vector meson contributions in addition to the pseudoscalar ones to hadronic matrix elements of current-current operators and the calculation of the corresponding Wilson coefficients in a momentum scheme at the NLO improved significantly the matching between quark-gluon short distance contributions and meson long distance contributions over our results in 1986. We obtain satisfactory description of the ${\rm Re}A_2$ amplitude and ${\rm Re}A_0/{\rm Re}A_2=16.0\pm 1.5$ to be compared with its experimental value of $22.3$. While this difference could be the result of present theoretical uncertainties in our approach, it cannot be excluded that New Physics (NP) is here at work. The analysis by Fulvia De Fazio, Jennifer Girrbach-Noe and myself shows that indeed a tree-level $Z^\prime$ or $G^\prime$ exchanges with masses in the reach of the LHC and special couplings to quarks can significantly improve the theoretical status of the $\Delta I=1/2$ rule. I stress that our approach allows to understand the physics behind recent numerical results obtained in lattice QCD not only for the $\Delta I=1/2$ rule but also for the parameter $\hat B_K$ that enters the evaluation of $\varepsilon_K$. In contrast to the $\Delta I=1/2$ rule the chapter on $\hat B_K$ in QCD appears to be basically closed.