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hep-ph/0401065
Alexander Belyaev
A.Belyaev, M-H.Genest, C.Leroy, R.Mehdiyev
Signals from R-parity violating top quark decays at LHC
23 pages, 22 figures
JHEP0409:012,2004
10.1088/1126-6708/2004/09/012
FSU-HEP-031231
hep-ph
null
We evaluate the potential of the CERN LHC collider to observe rare decays of the top quark in channels involving R-parity violating (RPV) interactions. We stress the importance of calculating top quark production and decay simultaneously as a true 2->4 process. The process of tt-bar pair production followed by RPV decay of one of the top quarks is analyzed with fast detector simulation. We show that intermediate supersymmetric particles can be observed as resonances even if they are heavier than the top quark due to the significant off-shell top-quark mass effects. The approach where the top quark is produced on-mass-shell and then decays into 2- or 3-body final state would in general lead to incorrect kinematical distributions and rates. The rates of the 2 -> 4 process with top quark production and RPV 3-body decay depend on the total width of the heavy intermediate sfermion which could,therefore, be measured indirectly. We find that the LHC collider offers a unique potential to study rare top quark decays in the framework of supersymmetry with broken R-parity for branching fractions of RPV top decays as low as 10^{-6}
[ { "created": "Mon, 12 Jan 2004 20:56:46 GMT", "version": "v1" }, { "created": "Fri, 30 Jan 2004 19:01:17 GMT", "version": "v2" }, { "created": "Wed, 12 Jan 2005 22:51:28 GMT", "version": "v3" } ]
2008-11-26
[ [ "Belyaev", "A.", "" ], [ "Genest", "M-H.", "" ], [ "Leroy", "C.", "" ], [ "Mehdiyev", "R.", "" ] ]
We evaluate the potential of the CERN LHC collider to observe rare decays of the top quark in channels involving R-parity violating (RPV) interactions. We stress the importance of calculating top quark production and decay simultaneously as a true 2->4 process. The process of tt-bar pair production followed by RPV decay of one of the top quarks is analyzed with fast detector simulation. We show that intermediate supersymmetric particles can be observed as resonances even if they are heavier than the top quark due to the significant off-shell top-quark mass effects. The approach where the top quark is produced on-mass-shell and then decays into 2- or 3-body final state would in general lead to incorrect kinematical distributions and rates. The rates of the 2 -> 4 process with top quark production and RPV 3-body decay depend on the total width of the heavy intermediate sfermion which could,therefore, be measured indirectly. We find that the LHC collider offers a unique potential to study rare top quark decays in the framework of supersymmetry with broken R-parity for branching fractions of RPV top decays as low as 10^{-6}
1801.07091
Lian-Rong Dai
L.R.Dai, J.M.Dias and E.Oset
Disclosing $D^*\bar{D}^*$ molecular states in the $B_c^- \to \pi^- J/\psi \omega$ decay
13 pages, 6 figures
null
10.1140/epjc/s10052-018-5702-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $B_c^- \to \pi^- J/\psi \omega$ and $B_c^- \to \pi^- D^* \bar{D}^*$ reactions and show that they are related by the presence of two resonances, the $X(3940)$ and $X(3930)$, that are of molecular nature and couple most strongly to $D^* \bar{D}^*$, but also to $J/\psi\omega$. Because of that, in the $J/\psi\omega$ mass distribution we find a cusp with large strength at the $D^* \bar{D}^*$ threshold and predict the ratio of strengths between the peak of the cusp and the maximum of the $D^* \bar{D}^*$ distribution close to $D^* \bar{D}^*$ threshold, which are distinct features of the molecular nature of these two resonances.
[ { "created": "Mon, 22 Jan 2018 13:44:52 GMT", "version": "v1" } ]
2018-04-04
[ [ "Dai", "L. R.", "" ], [ "Dias", "J. M.", "" ], [ "Oset", "E.", "" ] ]
We study the $B_c^- \to \pi^- J/\psi \omega$ and $B_c^- \to \pi^- D^* \bar{D}^*$ reactions and show that they are related by the presence of two resonances, the $X(3940)$ and $X(3930)$, that are of molecular nature and couple most strongly to $D^* \bar{D}^*$, but also to $J/\psi\omega$. Because of that, in the $J/\psi\omega$ mass distribution we find a cusp with large strength at the $D^* \bar{D}^*$ threshold and predict the ratio of strengths between the peak of the cusp and the maximum of the $D^* \bar{D}^*$ distribution close to $D^* \bar{D}^*$ threshold, which are distinct features of the molecular nature of these two resonances.
hep-ph/0405058
Howard Baer
Howard Baer, Tadas Krupovnickas and Xerxes Tata
Two Photon Background and the Reach of a Linear Collider for Supersymmetry in WMAP Favored Coannihilation Regions
19 pages including 9 eps figures
JHEP 0406:061,2004
10.1088/1126-6708/2004/06/061
FSU-HEP-040505, UH-511-1050-04
hep-ph
null
A neutralino relic density in accord with WMAP measurements can be found in the minimal supergravity (mSUGRA) model in several regions of parameter space: the stau co-annihilation corridor at low m_0 and the hyperbolic branch/focus point (HB/FP) region at large m_0 at the edges of parameter space, and the bulk and Higgs boson funnel regions within. In the regions at the edge, the mass gap between the next-to-lightest SUSY particle (NLSP) and the lightest SUSY particle (LSP) becomes small, and backgrounds from $\gamma\gamma\to f\bar{f}$ ($f$ is a SM fermion) become important for NLSP detection at an $e^+e^-$ linear collider. We evaluate these backgrounds from bremsstrahlung and beamstrahlung photons, and demonstrate that these do not preclude the observability of the signal for the cases where either the stau or the chargino is the NLSP. We also delineate the additional portion of the stau coannihilation region, beyond what can be accessed via a search for selectrons and smuons, that can be probed by a search for di-tau-jet events plus missing energy. The reach of a LC for SUSY in the HB/FP region is shown for an updated value of $m_t\simeq 180$ GeV as recently measured by the $D\O$ experiment.
[ { "created": "Thu, 6 May 2004 19:02:33 GMT", "version": "v1" } ]
2011-01-25
[ [ "Baer", "Howard", "" ], [ "Krupovnickas", "Tadas", "" ], [ "Tata", "Xerxes", "" ] ]
A neutralino relic density in accord with WMAP measurements can be found in the minimal supergravity (mSUGRA) model in several regions of parameter space: the stau co-annihilation corridor at low m_0 and the hyperbolic branch/focus point (HB/FP) region at large m_0 at the edges of parameter space, and the bulk and Higgs boson funnel regions within. In the regions at the edge, the mass gap between the next-to-lightest SUSY particle (NLSP) and the lightest SUSY particle (LSP) becomes small, and backgrounds from $\gamma\gamma\to f\bar{f}$ ($f$ is a SM fermion) become important for NLSP detection at an $e^+e^-$ linear collider. We evaluate these backgrounds from bremsstrahlung and beamstrahlung photons, and demonstrate that these do not preclude the observability of the signal for the cases where either the stau or the chargino is the NLSP. We also delineate the additional portion of the stau coannihilation region, beyond what can be accessed via a search for selectrons and smuons, that can be probed by a search for di-tau-jet events plus missing energy. The reach of a LC for SUSY in the HB/FP region is shown for an updated value of $m_t\simeq 180$ GeV as recently measured by the $D\O$ experiment.
2312.01799
Jiaxing Zhao
Jiaxing Zhao and Baoyi Chen
$J/\psi$ polarization in relativistic heavy ion collisions
6 pages, 4 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
Understanding the polarization property of $J/\psi$ is critical to constrain its production mechanism. In addition, the polarization of $J/\psi$ can reveal the impact of strong electromagnetic and vorticity fields in relativistic heavy ion collisions. In this study, we analyzed the yield and polarization of $J/\psi$ in relativistic heavy ion collisions at different centrality and transverse momentum regions, using three different reference frames: the Collins-Soper frame, the helicity frame, and the event plane frame. The polarization of initially produced $J/\psi$ is determined by the NRQCD calculation and is similar to that of $pp$ collisions. However, both unpolarization and transverse polarization are considered for the regenerated $J/\psi$. Our results indicate that the polarization at high $p_T$ is similar to that observed in $pp$ collisions. However, at low $p_T$, where regenerated $J/\psi$ dominates, it is likely that the polarized charm quarks in the rotational QGP medium are responsible for this phenomenon. Our study supplies a baseline for future research on the effects of strong electromagnetic and vorticity fields on $J/\psi$ polarization.
[ { "created": "Mon, 4 Dec 2023 10:44:11 GMT", "version": "v1" } ]
2023-12-05
[ [ "Zhao", "Jiaxing", "" ], [ "Chen", "Baoyi", "" ] ]
Understanding the polarization property of $J/\psi$ is critical to constrain its production mechanism. In addition, the polarization of $J/\psi$ can reveal the impact of strong electromagnetic and vorticity fields in relativistic heavy ion collisions. In this study, we analyzed the yield and polarization of $J/\psi$ in relativistic heavy ion collisions at different centrality and transverse momentum regions, using three different reference frames: the Collins-Soper frame, the helicity frame, and the event plane frame. The polarization of initially produced $J/\psi$ is determined by the NRQCD calculation and is similar to that of $pp$ collisions. However, both unpolarization and transverse polarization are considered for the regenerated $J/\psi$. Our results indicate that the polarization at high $p_T$ is similar to that observed in $pp$ collisions. However, at low $p_T$, where regenerated $J/\psi$ dominates, it is likely that the polarized charm quarks in the rotational QGP medium are responsible for this phenomenon. Our study supplies a baseline for future research on the effects of strong electromagnetic and vorticity fields on $J/\psi$ polarization.
hep-ph/0112199
Bernd Andreas Kniehl
Bernd A. Kniehl, Lennart Zwirner (Hamburg U.)
J/psi Inclusive Production in ep Deep-Inelastic Scattering at DESY HERA
27 pages (Latex), 9 figures (Postscript), to appear in Nucl. Phys. B
Nucl.Phys.B621:337-358,2002
10.1016/S0550-3213(01)00564-8
DESY 01-196, MPI/PhT/2001-29
hep-ph hep-ex
null
We calculate the cross section of J/psi plus jet associated production in ep deep-inelastic scattering within the factorization formalism of nonrelativistic quantum chromodynamics. Our analytic results disagree with previous analyses, both for the colour-singlet and colour-octet channels. Our theoretical predictions agree reasonably well with recent data taken by the H1 Collaboration at DESY HERA, significantly better than those obtained within the colour-singlet model.
[ { "created": "Fri, 14 Dec 2001 11:21:49 GMT", "version": "v1" } ]
2011-03-23
[ [ "Kniehl", "Bernd A.", "", "Hamburg U." ], [ "Zwirner", "Lennart", "", "Hamburg U." ] ]
We calculate the cross section of J/psi plus jet associated production in ep deep-inelastic scattering within the factorization formalism of nonrelativistic quantum chromodynamics. Our analytic results disagree with previous analyses, both for the colour-singlet and colour-octet channels. Our theoretical predictions agree reasonably well with recent data taken by the H1 Collaboration at DESY HERA, significantly better than those obtained within the colour-singlet model.
hep-ph/0509168
Manuel Paucar
A.V.Gladyshev, D.I.Kazakov, M.G.Paucar
Production of Long-Lived Sleptons at LHC
LaTex, 8 pages, 6 eps figures
Mod.Phys.Lett. A20 (2005) 3085-3094
10.1142/S0217732305019195
null
hep-ph
null
We analyse the MSSM parameter space and discuss the narrow band near the so-called co-annihilation region where sleptons may be long-lived particles. This region is consistent with the WMAP restrictions on the Dark matter and depends on the value of $\tan\beta$. In this region staus are long-lived and may go through the detector. Due to a relatively small mass (150 $\div$ 850 GeV) their production cross-section at LHC may reach a few % pb.
[ { "created": "Fri, 16 Sep 2005 12:54:02 GMT", "version": "v1" } ]
2009-11-11
[ [ "Gladyshev", "A. V.", "" ], [ "Kazakov", "D. I.", "" ], [ "Paucar", "M. G.", "" ] ]
We analyse the MSSM parameter space and discuss the narrow band near the so-called co-annihilation region where sleptons may be long-lived particles. This region is consistent with the WMAP restrictions on the Dark matter and depends on the value of $\tan\beta$. In this region staus are long-lived and may go through the detector. Due to a relatively small mass (150 $\div$ 850 GeV) their production cross-section at LHC may reach a few % pb.
1402.3738
Fred Jegerlehner
Fred Jegerlehner
Higgs inflation and the cosmological constant
39 pages, 25 figures, 1 table. Replacement: typos corrected, Eq (3) corrected, notation adjusted
Acta Phys.Polon. B45 (2014) 1215-1254
10.5506/APhysPolB.45.1215
DESY~14-013, HU-EP-14/05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Higgs not only induces the masses of all SM particles, the Higgs, given its special mass value, is the natural candidate for the inflaton and in fact is ruling the evolution of the early universe, by providing the necessary dark energy which remains the dominant energy density. SM running couplings not only allow us to extrapolate SM physics up to the Planck scale, but equally important they are triggering the Higgs mechanism. This is possible by the fact that the bare mass term in the Higgs potential changes sign at about mu_0 = 1.4x10^16 GeV and in the symmetric phase is enhanced by quadratic terms in the Planck mass. Such a huge Higgs mass term is able to play a key role in triggering inflation in the early universe. In this article we extend our previous investigation by working out the details of a Higgs inflation scenario. We show how different terms contributing to the Higgs Lagrangian are affecting inflation. Given the SM and its extrapolation to scales mu>mu_0 we find a calculable cosmological constant V(0) which is weakly scale dependent and actually remains large during inflation. This is different to the Higgs fluctuation field dependent Delta V(phi), which decays exponentially during inflation, and actually would not provide a sufficient amount of inflation. The fluctuation field has a different effective mass which shifts the bare Higgs transition point to a lower value mu'_0 = 7.7x10^14 GeV. The vacuum energy V(0) being proportional to M_Pl^4 has a coefficient which vanishes near the Higgs transition point, such that the bare and the renormalized cosmological constant match at this point. The role of the Higgs in reheating and baryogenesis is emphasized.
[ { "created": "Sun, 16 Feb 2014 00:23:52 GMT", "version": "v1" }, { "created": "Wed, 2 Jul 2014 02:14:49 GMT", "version": "v2" } ]
2015-06-18
[ [ "Jegerlehner", "Fred", "" ] ]
The Higgs not only induces the masses of all SM particles, the Higgs, given its special mass value, is the natural candidate for the inflaton and in fact is ruling the evolution of the early universe, by providing the necessary dark energy which remains the dominant energy density. SM running couplings not only allow us to extrapolate SM physics up to the Planck scale, but equally important they are triggering the Higgs mechanism. This is possible by the fact that the bare mass term in the Higgs potential changes sign at about mu_0 = 1.4x10^16 GeV and in the symmetric phase is enhanced by quadratic terms in the Planck mass. Such a huge Higgs mass term is able to play a key role in triggering inflation in the early universe. In this article we extend our previous investigation by working out the details of a Higgs inflation scenario. We show how different terms contributing to the Higgs Lagrangian are affecting inflation. Given the SM and its extrapolation to scales mu>mu_0 we find a calculable cosmological constant V(0) which is weakly scale dependent and actually remains large during inflation. This is different to the Higgs fluctuation field dependent Delta V(phi), which decays exponentially during inflation, and actually would not provide a sufficient amount of inflation. The fluctuation field has a different effective mass which shifts the bare Higgs transition point to a lower value mu'_0 = 7.7x10^14 GeV. The vacuum energy V(0) being proportional to M_Pl^4 has a coefficient which vanishes near the Higgs transition point, such that the bare and the renormalized cosmological constant match at this point. The role of the Higgs in reheating and baryogenesis is emphasized.
hep-ph/0511202
Antonio Enrique Carcamo Hernandez acarcamo
A. Carcamo
The Gell-Mann-Okubo and Colemann-Glashow relations for octet and decuplet baryons in the $SU_q(3)$ quantum algebra
19 pages, 4 figures. Corrected typos
J.Math.Phys.47:073509,2006
10.1063/1.2218672
null
hep-ph
null
The q-deformed Clebsch-Gordan coefficients corresponding to the $\lrpy{3}\times\lrpy{21}$ reduction of the $SU_q(3)$ quantum algebra are computed. From these results and using the quantum Clebsch-Gordan coefficients for the $\lrpy{21}\times\lrpy{21}$ reduction found by Zhong Qi Ma, the q-deformed Gell-Mann-Okubo mass relations for octet and decuplet baryons are determined by generalizing the procedure used for the SU(3) algebra. We also determine the Coleman-Glashow relations for octet and decuplet baryons in the $SU_q(3)$ algebra. Finally, by using the experimental particle masses of the octet and decuplet baryons, two values of the $q$-parameter are found and adjusted for the predicted masses expressions (one for the Gell-Mann-Okubo mass relations and the other for the Coleman-Glashow relations) and a possible physical interpretation is given.
[ { "created": "Wed, 16 Nov 2005 17:36:24 GMT", "version": "v1" }, { "created": "Sat, 17 Jun 2006 23:54:05 GMT", "version": "v2" }, { "created": "Thu, 10 Aug 2006 13:08:49 GMT", "version": "v3" } ]
2014-11-18
[ [ "Carcamo", "A.", "" ] ]
The q-deformed Clebsch-Gordan coefficients corresponding to the $\lrpy{3}\times\lrpy{21}$ reduction of the $SU_q(3)$ quantum algebra are computed. From these results and using the quantum Clebsch-Gordan coefficients for the $\lrpy{21}\times\lrpy{21}$ reduction found by Zhong Qi Ma, the q-deformed Gell-Mann-Okubo mass relations for octet and decuplet baryons are determined by generalizing the procedure used for the SU(3) algebra. We also determine the Coleman-Glashow relations for octet and decuplet baryons in the $SU_q(3)$ algebra. Finally, by using the experimental particle masses of the octet and decuplet baryons, two values of the $q$-parameter are found and adjusted for the predicted masses expressions (one for the Gell-Mann-Okubo mass relations and the other for the Coleman-Glashow relations) and a possible physical interpretation is given.
hep-ph/0107193
Willy van Neerven
W.L. van Neerven
Production of Heavy Quarks in Deep-Inelastic Lepton-Hadron Scattering scattering
18 pages LaTeX, 3 postscript figures. To appear in the proceedings of the conference MRST 2001, London, Ontario, Canada, May 15-18
null
10.1063/1.1435523
null
hep-ph
null
We will give a review of the computation of exact next-to-leading order corrections to heavy quark production in deep inelastic lepton-hadron scattering and discuss the progress made in this field over the past ten years. In this approach, hereafter called EXACT, where the heavy quark mass is taken to be of the same order of magnitude as the other large scales in the process, one can apply perturbation theory in all orders of the strong coupling constant alpha_s. The results are compared with another approach, called the variable flavor number scheme (VFNS), where the heavy quark is also treated as a massless quark. It turns out that the differences between the two approaches are very small provided both of them are carried out up to next-to-next-to-leading order.
[ { "created": "Tue, 17 Jul 2001 14:38:23 GMT", "version": "v1" } ]
2009-11-07
[ [ "van Neerven", "W. L.", "" ] ]
We will give a review of the computation of exact next-to-leading order corrections to heavy quark production in deep inelastic lepton-hadron scattering and discuss the progress made in this field over the past ten years. In this approach, hereafter called EXACT, where the heavy quark mass is taken to be of the same order of magnitude as the other large scales in the process, one can apply perturbation theory in all orders of the strong coupling constant alpha_s. The results are compared with another approach, called the variable flavor number scheme (VFNS), where the heavy quark is also treated as a massless quark. It turns out that the differences between the two approaches are very small provided both of them are carried out up to next-to-next-to-leading order.
2010.05014
Xiang Liu
Hong-Tao An, Kan Chen, Xiang Liu
Manifestly exotic pentaquarks with a single heavy quark
19 pages, 15 figures and 3 tables
Phys. Rev. D105, 034018 (2022)
10.1103/PhysRevD.105.034018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the observed $X(2900)$, we study systematically the mass spectra of the ground pentaquark states with the $qqqq\bar{Q}$ ($Q=c,b$; $q=n,s$; $n=u,d$) configuration in the framework of the Chromomagnetic Interaction model. We present a detailed analysis of their stabilities and decay behaviors. Our results indicate that there may exist narrow states or even stable states. We hope that the present study may inspire experimentalist's interest in searching for such a type of the exotic pentaquark state.
[ { "created": "Sat, 10 Oct 2020 14:34:28 GMT", "version": "v1" }, { "created": "Sun, 30 Jan 2022 02:27:39 GMT", "version": "v2" }, { "created": "Sat, 12 Feb 2022 02:43:37 GMT", "version": "v3" }, { "created": "Sat, 19 Feb 2022 00:42:37 GMT", "version": "v4" } ]
2022-02-22
[ [ "An", "Hong-Tao", "" ], [ "Chen", "Kan", "" ], [ "Liu", "Xiang", "" ] ]
Inspired by the observed $X(2900)$, we study systematically the mass spectra of the ground pentaquark states with the $qqqq\bar{Q}$ ($Q=c,b$; $q=n,s$; $n=u,d$) configuration in the framework of the Chromomagnetic Interaction model. We present a detailed analysis of their stabilities and decay behaviors. Our results indicate that there may exist narrow states or even stable states. We hope that the present study may inspire experimentalist's interest in searching for such a type of the exotic pentaquark state.
1905.09412
Zhaoxia Heng
Zhaoxia Heng, Lin Guo, Pengqiang Sun, Wei Wei
Charged Higgs bosons in the NMSSM under current LHC constraints
15 pages,6 figures. Accepted by Modern Physics Letters A
Modern Physics Letters A, Vol. 33, No. 1 (2019) 1950230
10.1142/S0217732319502304
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charged Higgs boson is a crucial prediction of new physics beyond the SM. In this work, we perform a comprehensive scan over the parameter space of NMSSM considering various experimental constraints including the direct search limits from the 13 TeV LHC, and consider the scenario that the next-to-lightest CP-even Higgs boson is SM-like. We find that the masses of charged Higgs bosons can be as light as 350 GeV, the lightest CP-even Higgs boson $h_1$ is predominantly singlet and can be as light as 48 GeV, and the lightest CP-odd Higgs boson $a_1$ is also singlet-dominated and can be as light as 82 GeV. The charged Higgs bosons mainly decay to $t\bar{b}$ or $\bar{t} b$, but the branching ratio of the exotic decays $H^\pm\to W^\pm h_1$ and $H^\pm\to W^\pm a_1$ can maximally reach to 20\% and 11\%, respectively, which can be used to distinguish the NMSSM from MSSM. Such a heavy charged Higgs boson is unaccessible at the 13 TeV LHC with a luminosity of 36.1 $\rm fb^{-1}$ and its detection needs higher energy and/or higher luminosity.
[ { "created": "Thu, 23 May 2019 00:26:49 GMT", "version": "v1" }, { "created": "Mon, 17 Jun 2019 00:46:50 GMT", "version": "v2" } ]
2019-06-18
[ [ "Heng", "Zhaoxia", "" ], [ "Guo", "Lin", "" ], [ "Sun", "Pengqiang", "" ], [ "Wei", "Wei", "" ] ]
Charged Higgs boson is a crucial prediction of new physics beyond the SM. In this work, we perform a comprehensive scan over the parameter space of NMSSM considering various experimental constraints including the direct search limits from the 13 TeV LHC, and consider the scenario that the next-to-lightest CP-even Higgs boson is SM-like. We find that the masses of charged Higgs bosons can be as light as 350 GeV, the lightest CP-even Higgs boson $h_1$ is predominantly singlet and can be as light as 48 GeV, and the lightest CP-odd Higgs boson $a_1$ is also singlet-dominated and can be as light as 82 GeV. The charged Higgs bosons mainly decay to $t\bar{b}$ or $\bar{t} b$, but the branching ratio of the exotic decays $H^\pm\to W^\pm h_1$ and $H^\pm\to W^\pm a_1$ can maximally reach to 20\% and 11\%, respectively, which can be used to distinguish the NMSSM from MSSM. Such a heavy charged Higgs boson is unaccessible at the 13 TeV LHC with a luminosity of 36.1 $\rm fb^{-1}$ and its detection needs higher energy and/or higher luminosity.
hep-ph/9504220
John Collins
Xavier Artru and John Collins
Measuring transverse spin correlations by 4-particle correlations in $e^+ e^-\to 2 \ {\rm jets}$
19 pages in RevTeX 3.0 and epsf, with 3 figure files (tarred, compressed uuencoded encapsulated postcript). Postscript version of paper available at ftp://ftp.phys.psu.edu/pub/preprint/psuth158/psuth158.ps Revised version has extra references, and correction of misprint in Eq. (7)
Z.Phys.C69:277-286,1996
10.1007/s002880050028
PSU/TH/158
hep-ph
null
The azimuthal distribution of pairs of particles in a jet is sensitive to the transverse polarization of the quark initiating the jet, but with a sensitivity that involves a nonperturbative analyzing power. We show in detail how to measure the analyzing power from 4-hadron correlations in $e^+ e^- \to 2 \ {\rm jets}$. We explain the combinations of particle flavor that are likely to give the biggest effect.
[ { "created": "Tue, 4 Apr 1995 22:07:37 GMT", "version": "v1" }, { "created": "Tue, 18 Apr 1995 19:42:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Artru", "Xavier", "" ], [ "Collins", "John", "" ] ]
The azimuthal distribution of pairs of particles in a jet is sensitive to the transverse polarization of the quark initiating the jet, but with a sensitivity that involves a nonperturbative analyzing power. We show in detail how to measure the analyzing power from 4-hadron correlations in $e^+ e^- \to 2 \ {\rm jets}$. We explain the combinations of particle flavor that are likely to give the biggest effect.
2112.13533
Shinya Matsuzaki
Chuan-Xin Cui, Hiroyuki Ishida, Mamiya Kawaguchi, Jin-Yang Li, Shinya Matsuzaki, and Akio Tomiya
QCD knows new quarks
22 pages, 5 figures; analysis updated, several discussions and references added; claims further refined
Universe 2024, 10(2), 68
10.3390/universe10020068
null
hep-ph hep-ex hep-lat nucl-th
http://creativecommons.org/licenses/by/4.0/
We find that a big gap between indicators for the breaking strengths of the global chiral SU(2) and U(1) axial symmetries in QCD of the Standard Model (SM) can be interpreted as a new fine-tuning problem. This may thus imply calling for a class of Beyond the SM, which turns out to favor having a new chiral symmetry and the associated massless new quark insensitive to the chiral SU(2) symmetry for the lightest up and down quarks, so that the fine-tuning is relaxed. Our statistical estimate shows that QCD of the SM is by more than 300 standard deviations off the desired parameter space, which is free from the fine-tuning, and the significance will be greater as the lattice measurements on the QCD hadron observables get more accurate. As one viable candidate, we introduce a dark QCD model with massless new quarks, which can survive current experimental, cosmological, and astrophysical limits, and also leave various phenomenological and cosmological consequences, to be probed in the future. This is a new indication from QCD, which gives a new avenue to deeper understand QCD, and provides a new guideline to consider going beyond the SM.
[ { "created": "Mon, 27 Dec 2021 06:18:12 GMT", "version": "v1" }, { "created": "Mon, 14 Feb 2022 06:54:22 GMT", "version": "v2" }, { "created": "Fri, 16 Dec 2022 04:23:34 GMT", "version": "v3" }, { "created": "Thu, 26 Oct 2023 03:13:01 GMT", "version": "v4" } ]
2024-02-05
[ [ "Cui", "Chuan-Xin", "" ], [ "Ishida", "Hiroyuki", "" ], [ "Kawaguchi", "Mamiya", "" ], [ "Li", "Jin-Yang", "" ], [ "Matsuzaki", "Shinya", "" ], [ "Tomiya", "Akio", "" ] ]
We find that a big gap between indicators for the breaking strengths of the global chiral SU(2) and U(1) axial symmetries in QCD of the Standard Model (SM) can be interpreted as a new fine-tuning problem. This may thus imply calling for a class of Beyond the SM, which turns out to favor having a new chiral symmetry and the associated massless new quark insensitive to the chiral SU(2) symmetry for the lightest up and down quarks, so that the fine-tuning is relaxed. Our statistical estimate shows that QCD of the SM is by more than 300 standard deviations off the desired parameter space, which is free from the fine-tuning, and the significance will be greater as the lattice measurements on the QCD hadron observables get more accurate. As one viable candidate, we introduce a dark QCD model with massless new quarks, which can survive current experimental, cosmological, and astrophysical limits, and also leave various phenomenological and cosmological consequences, to be probed in the future. This is a new indication from QCD, which gives a new avenue to deeper understand QCD, and provides a new guideline to consider going beyond the SM.
hep-ph/0101105
Peter Richardson
Peter Richardson
Simulations of R-parity Violating SUSY Models
207 pages, PhD thesis
null
null
null
hep-ph
null
In recent years there has been a great deal of interest in R-parity violating supersymmetric models. We explain the motivation for studying these models and explore the various phenomenological consequences of R-parity violation. It has become essential for the experimental study of any new model to have a Monte Carlo event generator which includes the processes predicted by that model. We review the techniques used in the construction of these simulations and show how we have extended the HERWIG event generator to include R-parity violating processes. We discuss how to treat the emission of QCD radiation in these processes including colour coherence effects via the angular-ordered parton shower. We then make use of this simulation to investigate the discovery potential for resonant slepton production, via either supersymmetric gauge or R-parity violating decay modes, in hadron-hadron collisions. Finally, we look at the possibility that the KARMEN time anomaly can be explained by the existence of a light neutralino which is produced and decays via R-parity violation.
[ { "created": "Wed, 10 Jan 2001 19:58:41 GMT", "version": "v1" } ]
2009-09-25
[ [ "Richardson", "Peter", "" ] ]
In recent years there has been a great deal of interest in R-parity violating supersymmetric models. We explain the motivation for studying these models and explore the various phenomenological consequences of R-parity violation. It has become essential for the experimental study of any new model to have a Monte Carlo event generator which includes the processes predicted by that model. We review the techniques used in the construction of these simulations and show how we have extended the HERWIG event generator to include R-parity violating processes. We discuss how to treat the emission of QCD radiation in these processes including colour coherence effects via the angular-ordered parton shower. We then make use of this simulation to investigate the discovery potential for resonant slepton production, via either supersymmetric gauge or R-parity violating decay modes, in hadron-hadron collisions. Finally, we look at the possibility that the KARMEN time anomaly can be explained by the existence of a light neutralino which is produced and decays via R-parity violation.
hep-ph/9207258
Jean Orloff
J.-M. Fr\`ere J.M. Moreno M. Tytgat J. Orloff
LEP1 vs. Future Colliders: Effective Operators And Extended Gauge Group
14 pages , CERN-TH.6573/92 ULB.TH.04/92 (phyzzx, 3 eps-figs incl.)
Phys.Lett. B292 (1992) 348-352
10.1016/0370-2693(92)91186-D
null
hep-ph
null
In an effective Lagrangian approach to physics beyond the Standard Model, it has been argued that imposing $SU(2) \times U(1)$ invariance severely restricts the discovery potential of future colliders. We exhibit a possible way out in an extended gauge group context.
[ { "created": "Fri, 24 Jul 1992 18:30:36 GMT", "version": "v1" } ]
2009-10-22
[ [ "Orloff", "J. -M. Frère J. M. Moreno M. Tytgat J.", "" ] ]
In an effective Lagrangian approach to physics beyond the Standard Model, it has been argued that imposing $SU(2) \times U(1)$ invariance severely restricts the discovery potential of future colliders. We exhibit a possible way out in an extended gauge group context.
hep-ph/9703230
Abdelhak Djouadi
Abdelhak Djouadi (LPM, Univ. Montpellier)
SUSY Higgs Boson Decays
10 pages, latex, 3 figures
null
null
PM-97-01
hep-ph
null
I discuss the decay modes of the neutral and charged Higgs bosons in the minimal supersymmetric extension of the Standard Model. Special emphasis will be put on the the QCD corrections to the hadronic decay modes, the below threshold -three body- decays and the decays into supersymmetric particles, charginos, neutralinos and sfermions. A Fortran code calculating the various Higgs decay branching ratios is then briefly presented. [Talk given at the Ringberg Workshop The Higgs Puzzle, Ringberg Castle, Tegernsee, Germany, December 8-13 1996; to appear in the proceedings.]
[ { "created": "Tue, 4 Mar 1997 14:46:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Djouadi", "Abdelhak", "", "LPM, Univ. Montpellier" ] ]
I discuss the decay modes of the neutral and charged Higgs bosons in the minimal supersymmetric extension of the Standard Model. Special emphasis will be put on the the QCD corrections to the hadronic decay modes, the below threshold -three body- decays and the decays into supersymmetric particles, charginos, neutralinos and sfermions. A Fortran code calculating the various Higgs decay branching ratios is then briefly presented. [Talk given at the Ringberg Workshop The Higgs Puzzle, Ringberg Castle, Tegernsee, Germany, December 8-13 1996; to appear in the proceedings.]
1709.08342
Hannu Paukkunen
Hannu Paukkunen (for the LHeC study group)
An update on nuclear PDFs at the LHeC
A transcript of the talk given in XXV International Workshop on Deep-Inelastic Scattering and Related Subjects
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The prospects for a measurement of nuclear parton distribution functions (PDFs) at the Large Hadron--Electron Collider are discussed in the light of recent progress made in the front of global analysis of nuclear PDFs.
[ { "created": "Mon, 25 Sep 2017 06:44:11 GMT", "version": "v1" } ]
2019-08-12
[ [ "Paukkunen", "Hannu", "", "for the LHeC study group" ] ]
The prospects for a measurement of nuclear parton distribution functions (PDFs) at the Large Hadron--Electron Collider are discussed in the light of recent progress made in the front of global analysis of nuclear PDFs.
2205.07350
Fernando Cornet-Gomez
Francisco J. Botella, Fernando Cornet-Gomez, Carlos Mir\'o and Miguel Nebot
Leptonic $g-2$ in 2HDM
Contribution to the 2022 Electroweak session of the 56th Rencontres de Moriond
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The experimental observations of the electron and muon anomalous magnetic moment present discrepancies with respect to the Standard Model predictions. A class of flavor conserving Two Higgs Doublet model, stable under renormalization, that is capable of explaining both anomalies simultaneously is presented. This model can also explain an excess observed by ATLAS in $\sigma(pp\to S)_{[\text{ggF}]}\times \text{Br}(S\to\tau^+\tau^-)$.
[ { "created": "Sun, 15 May 2022 18:20:41 GMT", "version": "v1" } ]
2022-05-17
[ [ "Botella", "Francisco J.", "" ], [ "Cornet-Gomez", "Fernando", "" ], [ "Miró", "Carlos", "" ], [ "Nebot", "Miguel", "" ] ]
The experimental observations of the electron and muon anomalous magnetic moment present discrepancies with respect to the Standard Model predictions. A class of flavor conserving Two Higgs Doublet model, stable under renormalization, that is capable of explaining both anomalies simultaneously is presented. This model can also explain an excess observed by ATLAS in $\sigma(pp\to S)_{[\text{ggF}]}\times \text{Br}(S\to\tau^+\tau^-)$.
2208.01293
Dominik St\"ockinger
Matthias Wei{\ss}wange, Dumitru M. Ghilencea, Dominik St\"ockinger
Quantum scale invariance in gauge theories and applications to muon production
20 pages, version to be published in Phys.Rev.D
null
10.1103/PhysRevD.107.085008
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss quantum scale invariance in (scale invariant) gauge theories with both ultraviolet (UV) and infrared (IR) divergences. Firstly, their BRST invariance is checked in two apparently unrelated approaches using a scale invariant regularisation (SIR). These approaches are then shown to be equivalent. Secondly, for the Abelian case we discuss both UV and IR quantum corrections present in such theories. We present the Feynman rules in a form suitable for offshell Green functions calculations, together with their one-loop renormalisation. This information is then used for the muon production cross section at one-loop in a quantum scale invariant theory. Such a theory contains not only new UV poles but also IR poles. While the UV poles bring new quantum corrections (in the form of counterterms), finite or divergent, that we compute, it is shown that the IR poles do not bring new physics. The IR quantum corrections, both finite and divergent, cancel out similarly to the way the IR poles themselves cancel in the traditional approach to IR divergences (in the cross section, after summing over virtual and real corrections). Hence, the evanescent interactions induced by the scale-invariant analytical continuation of the SIR scheme do not affect IR physics, as illustrated at one-loop for the muon production ($e^+ e^- \to \mu^+\mu^-$) cross section.
[ { "created": "Tue, 2 Aug 2022 07:37:54 GMT", "version": "v1" }, { "created": "Thu, 16 Mar 2023 09:07:53 GMT", "version": "v2" } ]
2023-04-19
[ [ "Weißwange", "Matthias", "" ], [ "Ghilencea", "Dumitru M.", "" ], [ "Stöckinger", "Dominik", "" ] ]
We discuss quantum scale invariance in (scale invariant) gauge theories with both ultraviolet (UV) and infrared (IR) divergences. Firstly, their BRST invariance is checked in two apparently unrelated approaches using a scale invariant regularisation (SIR). These approaches are then shown to be equivalent. Secondly, for the Abelian case we discuss both UV and IR quantum corrections present in such theories. We present the Feynman rules in a form suitable for offshell Green functions calculations, together with their one-loop renormalisation. This information is then used for the muon production cross section at one-loop in a quantum scale invariant theory. Such a theory contains not only new UV poles but also IR poles. While the UV poles bring new quantum corrections (in the form of counterterms), finite or divergent, that we compute, it is shown that the IR poles do not bring new physics. The IR quantum corrections, both finite and divergent, cancel out similarly to the way the IR poles themselves cancel in the traditional approach to IR divergences (in the cross section, after summing over virtual and real corrections). Hence, the evanescent interactions induced by the scale-invariant analytical continuation of the SIR scheme do not affect IR physics, as illustrated at one-loop for the muon production ($e^+ e^- \to \mu^+\mu^-$) cross section.
2006.11879
Amit Adhikary
Amit Adhikary, Rahool Kumar Barman, Biplob Bhattacherjee
Prospects of non-resonant di-Higgs searches and Higgs boson self-coupling measurement at the HE-LHC using machine learning techniques
Version 2; Modified significance formula used; version accepted for publication in JHEP
JHEP 2012 (2020) 179
10.1007/JHEP12(2020)179
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The prospects of observing the non-resonant di-Higgs production in the Standard Model at the proposed high energy upgrade of the LHC, $viz.$ the HE-LHC$~$($\sqrt{s}=27~{\rm TeV}$ and $\mathcal{L} = 15~{\rm ab^{-1}}$) is studied. Various di-Higgs final states are considered based on their cleanliness and signal yields. The search for the non-resonant double Higgs production at the HE-LHC is performed in the $b\bar{b}\gamma\gamma$, $b\bar{b}\tau^{+}\tau^{-}$, $b\bar{b}WW^{*}$, $WW^{*}\gamma\gamma$, $b\bar{b}ZZ^{*}$ and $b\bar{b}\mu^{+}\mu^{-}$ channels. The signal-background discrimination is performed through multivariate analyses using the Boosted Decision Tree Decorrelated$~$(BDTD) algorithm in the$~$TMVA framework, the XGBoost toolkit and Deep Neural Network$~$(DNN). The variation in the kinematics of Higgs pair production as a function of the self-coupling of the Higgs boson, $\lambda_{h}$, is also studied. The ramifications of varying $\lambda_{h}$ on the $b\bar{b}\gamma\gamma$, $b\bar{b}\tau^{+}\tau^{-}$ and $b\bar{b}WW^{*}$ search analyses optimized for the SM hypothesis is also explored.
[ { "created": "Sun, 21 Jun 2020 19:05:43 GMT", "version": "v1" }, { "created": "Sat, 16 Jan 2021 18:08:01 GMT", "version": "v2" } ]
2021-01-19
[ [ "Adhikary", "Amit", "" ], [ "Barman", "Rahool Kumar", "" ], [ "Bhattacherjee", "Biplob", "" ] ]
The prospects of observing the non-resonant di-Higgs production in the Standard Model at the proposed high energy upgrade of the LHC, $viz.$ the HE-LHC$~$($\sqrt{s}=27~{\rm TeV}$ and $\mathcal{L} = 15~{\rm ab^{-1}}$) is studied. Various di-Higgs final states are considered based on their cleanliness and signal yields. The search for the non-resonant double Higgs production at the HE-LHC is performed in the $b\bar{b}\gamma\gamma$, $b\bar{b}\tau^{+}\tau^{-}$, $b\bar{b}WW^{*}$, $WW^{*}\gamma\gamma$, $b\bar{b}ZZ^{*}$ and $b\bar{b}\mu^{+}\mu^{-}$ channels. The signal-background discrimination is performed through multivariate analyses using the Boosted Decision Tree Decorrelated$~$(BDTD) algorithm in the$~$TMVA framework, the XGBoost toolkit and Deep Neural Network$~$(DNN). The variation in the kinematics of Higgs pair production as a function of the self-coupling of the Higgs boson, $\lambda_{h}$, is also studied. The ramifications of varying $\lambda_{h}$ on the $b\bar{b}\gamma\gamma$, $b\bar{b}\tau^{+}\tau^{-}$ and $b\bar{b}WW^{*}$ search analyses optimized for the SM hypothesis is also explored.
1109.4781
Jianhui Zhang
Wolfgang Hollik and Jian-Hui Zhang
Radiative Corrections to $H^0\to WW/ZZ$ in the MSSM
13 pages, 7 figures, version to appear in PRD
Phys.Rev.D84:055022,2011
10.1103/PhysRevD.84.055022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The electroweak $\mathcal O(\alpha)$ radiative corrections to the decay of the heavy CP-even MSSM Higgs boson to weak gauge bosons are presented. Due to the suppression of the tree-level $H^0WW/H^0ZZ$ coupling, the electroweak contributions to the partial decay width are significant. Although the effective Born decay width can be rather small for certain $M_{A^0}$ values (especially for large $\tan\beta$), the corrected partial widths at different values of $M_{A^0}$ are of comparable size.
[ { "created": "Thu, 22 Sep 2011 11:51:21 GMT", "version": "v1" } ]
2011-10-21
[ [ "Hollik", "Wolfgang", "" ], [ "Zhang", "Jian-Hui", "" ] ]
The electroweak $\mathcal O(\alpha)$ radiative corrections to the decay of the heavy CP-even MSSM Higgs boson to weak gauge bosons are presented. Due to the suppression of the tree-level $H^0WW/H^0ZZ$ coupling, the electroweak contributions to the partial decay width are significant. Although the effective Born decay width can be rather small for certain $M_{A^0}$ values (especially for large $\tan\beta$), the corrected partial widths at different values of $M_{A^0}$ are of comparable size.
1807.11511
Ben Keeshan
Ben Keeshan, Heather E. Logan, and Terry Pilkington (Carleton U.)
Custodial symmetry violation in the Georgi-Machacek model
28 pages, 9 figures, v2: 18 figures, new appendix,comments and parameter scans added, v2 accepted for publication in PRD, v3: Typos fixed
Phys. Rev. D 102, 015001 (2020)
10.1103/PhysRevD.102.015001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effects of custodial symmetry violation in the Georgi-Machacek (GM) model. The GM model adds isospin-triplet scalars to the Standard Model in a way that preserves custodial symmetry at tree level; however, this custodial symmetry has long been known to be violated at the one-loop level by hypercharge interactions. We consider the custodial-symmetric GM model to arise at some high scale as a result of an unspecified ultraviolet completion, and quantify the custodial symmetry violation induced as the model is run down to the weak scale. The measured value of the eletroweak rho parameter (along with unitarity considerations) lets us constrain the scale of the ultraviolet completion to lie below tens to hundreds of TeV. Subject to this constraint, we quantify the size of other custodial-symmetry-violating effects at the weak scale, including custodial symmetry violation in the couplings of the 125 GeV Higgs boson to W and Z boson pairs and mixings and mass splittings among the additional Higgs bosons in the theory. We find that these effects are small enough that they are unlikely to be probed by the Large Hadron Collider, but may be detectable at a future $e^+e^-$ collider.
[ { "created": "Mon, 30 Jul 2018 18:07:49 GMT", "version": "v1" }, { "created": "Sun, 31 May 2020 20:34:12 GMT", "version": "v2" }, { "created": "Mon, 13 Jul 2020 18:27:04 GMT", "version": "v3" } ]
2020-07-15
[ [ "Keeshan", "Ben", "", "Carleton U." ], [ "Logan", "Heather E.", "", "Carleton U." ], [ "Pilkington", "Terry", "", "Carleton U." ] ]
We study the effects of custodial symmetry violation in the Georgi-Machacek (GM) model. The GM model adds isospin-triplet scalars to the Standard Model in a way that preserves custodial symmetry at tree level; however, this custodial symmetry has long been known to be violated at the one-loop level by hypercharge interactions. We consider the custodial-symmetric GM model to arise at some high scale as a result of an unspecified ultraviolet completion, and quantify the custodial symmetry violation induced as the model is run down to the weak scale. The measured value of the eletroweak rho parameter (along with unitarity considerations) lets us constrain the scale of the ultraviolet completion to lie below tens to hundreds of TeV. Subject to this constraint, we quantify the size of other custodial-symmetry-violating effects at the weak scale, including custodial symmetry violation in the couplings of the 125 GeV Higgs boson to W and Z boson pairs and mixings and mass splittings among the additional Higgs bosons in the theory. We find that these effects are small enough that they are unlikely to be probed by the Large Hadron Collider, but may be detectable at a future $e^+e^-$ collider.
2005.11328
Debasish Borah
Debasish Borah, Suruj Jyoti Das, Abhijit Kumar Saha
Cosmic Inflation in Minimal $U(1)_{B-L}$ Model: Implications for (Non) Thermal Dark Matter and Leptogenesis
48 pages, 18 figures, minor revision, matches version accepted for publication in Eur. Phys. J. C
null
10.1140/epjc/s10052-021-08944-w
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possibility of realising cosmic inflation, dark matter (DM), baryon asymmetry of the universe (BAU) and light neutrino masses in non-supersymmetric minimal gauged $B-L$ extension of the standard model with three right handed neutrinos. The singlet scalar field responsible for spontaneous breaking of $B-L$ gauge symmetry also plays the role of inflaton by virtue of its non-minimal coupling to gravity. While the lightest right handed neutrino is the DM candidate, being stabilised by an additional $Z_2$ symmetry, we show by performing a detailed renormalisation group evolution (RGE) improved study of inflationary dynamics that thermal DM is generally overproduced due to insufficient annihilations through gauge and scalar portals. This happens due to strict upper limits obtained on gauge and other dimensionless couplings responsible for DM annihilation while assuming the non-minimal coupling to gravity to be at most of order unity. The non-thermal DM scenario is viable, with or without $Z_2$ symmetry, although in such a case the $B-L$ gauge sector remains decoupled from the inflationary dynamics due to tiny couplings. We also show that the reheat temperature predicted by the model prefers non-thermal leptogenesis with hierarchical right handed neutrinos while being consistent with other requirements.
[ { "created": "Fri, 22 May 2020 18:00:02 GMT", "version": "v1" }, { "created": "Thu, 4 Feb 2021 04:38:51 GMT", "version": "v2" } ]
2021-03-17
[ [ "Borah", "Debasish", "" ], [ "Das", "Suruj Jyoti", "" ], [ "Saha", "Abhijit Kumar", "" ] ]
We study the possibility of realising cosmic inflation, dark matter (DM), baryon asymmetry of the universe (BAU) and light neutrino masses in non-supersymmetric minimal gauged $B-L$ extension of the standard model with three right handed neutrinos. The singlet scalar field responsible for spontaneous breaking of $B-L$ gauge symmetry also plays the role of inflaton by virtue of its non-minimal coupling to gravity. While the lightest right handed neutrino is the DM candidate, being stabilised by an additional $Z_2$ symmetry, we show by performing a detailed renormalisation group evolution (RGE) improved study of inflationary dynamics that thermal DM is generally overproduced due to insufficient annihilations through gauge and scalar portals. This happens due to strict upper limits obtained on gauge and other dimensionless couplings responsible for DM annihilation while assuming the non-minimal coupling to gravity to be at most of order unity. The non-thermal DM scenario is viable, with or without $Z_2$ symmetry, although in such a case the $B-L$ gauge sector remains decoupled from the inflationary dynamics due to tiny couplings. We also show that the reheat temperature predicted by the model prefers non-thermal leptogenesis with hierarchical right handed neutrinos while being consistent with other requirements.
1103.3491
K. S. Babu
K.S. Babu
Recent Progress in SUSY GUTs
Based on talk presented at ICHEP 2010, Paris, To be published in PoS ICHEP 2010, 4 pages LaTeX
PoS ICHEP2010:379,2010
null
OSU-HEP-11-05
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After a brief review of the motivations for grand unification, I discuss the main challenges facing realistic SUSY GUT model building. Achieving doublet-triplet splitting without fine--tuning is chief among them. Symmetry breaking should occur consistently without unwanted Goldston bosons, \mu-term of order TeV for the MSSM Higgs fileds should emerge naturally, and realistic fermion masses with small quark mixing angles and large lepton mixing angles should be generated with some predictivity. Significant progress has been made over the years towards achieving these goals in the context of supersymmetric SO(10) GUT. A complete SO(10) model is presented along this line wherein, somewhat surprisingly, the GUT scale threshold corrections to the gauge couplings are found to be small. This results in a predictive scenario for proton lifetime. An interesting correlation between the d=6 (p\to e^+\pi^0) and d=5 (p\to \nu-bar K^+) decay amplitudes is observed. This class of models predicts that both proton decay modes should be observable with an improvement in the current sensitivity by about a factor of five to ten.
[ { "created": "Thu, 17 Mar 2011 19:34:18 GMT", "version": "v1" } ]
2011-11-10
[ [ "Babu", "K. S.", "" ] ]
After a brief review of the motivations for grand unification, I discuss the main challenges facing realistic SUSY GUT model building. Achieving doublet-triplet splitting without fine--tuning is chief among them. Symmetry breaking should occur consistently without unwanted Goldston bosons, \mu-term of order TeV for the MSSM Higgs fileds should emerge naturally, and realistic fermion masses with small quark mixing angles and large lepton mixing angles should be generated with some predictivity. Significant progress has been made over the years towards achieving these goals in the context of supersymmetric SO(10) GUT. A complete SO(10) model is presented along this line wherein, somewhat surprisingly, the GUT scale threshold corrections to the gauge couplings are found to be small. This results in a predictive scenario for proton lifetime. An interesting correlation between the d=6 (p\to e^+\pi^0) and d=5 (p\to \nu-bar K^+) decay amplitudes is observed. This class of models predicts that both proton decay modes should be observable with an improvement in the current sensitivity by about a factor of five to ten.
hep-ph/0106322
Antonio Lopez Maroto
J.A.R. Cembranos, A. Dobado, A.L. Maroto
Brane-skyrmions and wrapped states
35 pages, 7 figures. Revised version. Appendix and new references included. To appear in Phys. Rev. D
Phys.Rev.D65:026005,2002
10.1103/PhysRevD.65.026005
null
hep-ph hep-th
null
In the context of a brane world and including an induced curvature term in the brane action, we obtain the effective lagrangian for the Goldstone bosons (branons) associated with the spontaneous breaking of the translational invariance in the bulk. In addition to the branons, this effective action has Skyrmion-like solitonic states which can be understood as holes in the brane. We study their main properties such as mass and size, the Skyrmion-branon interaction and their possible fermionic quantization. We also consider states where the brane is wrapped around the extra dimensions and their relation with the brane-skyrmions. Finally, we extend our results to higher-dimensional branes, such as those appearing in M-theory, where brane-skyrmions could also be present.
[ { "created": "Thu, 28 Jun 2001 10:12:23 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2001 18:20:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cembranos", "J. A. R.", "" ], [ "Dobado", "A.", "" ], [ "Maroto", "A. L.", "" ] ]
In the context of a brane world and including an induced curvature term in the brane action, we obtain the effective lagrangian for the Goldstone bosons (branons) associated with the spontaneous breaking of the translational invariance in the bulk. In addition to the branons, this effective action has Skyrmion-like solitonic states which can be understood as holes in the brane. We study their main properties such as mass and size, the Skyrmion-branon interaction and their possible fermionic quantization. We also consider states where the brane is wrapped around the extra dimensions and their relation with the brane-skyrmions. Finally, we extend our results to higher-dimensional branes, such as those appearing in M-theory, where brane-skyrmions could also be present.
hep-ph/0512346
Rasulkhozha S. Sharafiddinov
Rasulkhozha S. Sharafiddinov
Family Structure of Leptons and Their Currents of an Axial Vector Nature
19 pages, LaTex
FizikaB16:1-16,2007
null
null
hep-ph
null
Each of neutrinos has a non - zero mass and regardless of whether it is a Dirac or a Majorana mass, can possess both anapole and electric dipole moments. Between their form factors appears a connection, for example, at the longitudinal neutrinos scattering on spinless nuclei. We discuss a theory, in which a mass consists of vector and axial - vector components responsible for separateness of leptonic current into the vector and axial - vector parts of the same charge or dipole moment. Such a model can explain the absence of truly neutral neutrinos vector interactions and the availability of an axial - vector structure of a Majorana mass. Thereby it relates the two neutrinos of a different nature. We derive an equation which unites the masses to a ratio of the anapole and electric dipole form factors of any lepton and its neutrino as a consequence of their unification in families of doublets and singlets. This testifies in favor of the existence of the left (right) dileptons and paradileptons of the axial - vector currents. Each of them answers to conservation of an axial - vector charge and any lepton flavor. Therefore, an axial - vector mass, anapole and electric dipole moment of the neutrino become proportional respectively to an axial - vector mass, anapole and electric dipole moment of a particle of the same families.
[ { "created": "Wed, 28 Dec 2005 04:10:13 GMT", "version": "v1" }, { "created": "Wed, 15 Mar 2006 03:27:57 GMT", "version": "v2" }, { "created": "Wed, 3 Jan 2007 08:51:03 GMT", "version": "v3" }, { "created": "Sun, 24 Jun 2007 06:19:44 GMT", "version": "v4" } ]
2008-11-26
[ [ "Sharafiddinov", "Rasulkhozha S.", "" ] ]
Each of neutrinos has a non - zero mass and regardless of whether it is a Dirac or a Majorana mass, can possess both anapole and electric dipole moments. Between their form factors appears a connection, for example, at the longitudinal neutrinos scattering on spinless nuclei. We discuss a theory, in which a mass consists of vector and axial - vector components responsible for separateness of leptonic current into the vector and axial - vector parts of the same charge or dipole moment. Such a model can explain the absence of truly neutral neutrinos vector interactions and the availability of an axial - vector structure of a Majorana mass. Thereby it relates the two neutrinos of a different nature. We derive an equation which unites the masses to a ratio of the anapole and electric dipole form factors of any lepton and its neutrino as a consequence of their unification in families of doublets and singlets. This testifies in favor of the existence of the left (right) dileptons and paradileptons of the axial - vector currents. Each of them answers to conservation of an axial - vector charge and any lepton flavor. Therefore, an axial - vector mass, anapole and electric dipole moment of the neutrino become proportional respectively to an axial - vector mass, anapole and electric dipole moment of a particle of the same families.
hep-ph/0105195
Boris Kopeliovich
M.B. Johnson, B.Z. Kopeliovich, I.K. Potashnikova, and P.L. McGaughey, J.M. Moss, J.C. Peng, G. Garvey, M. Leitch, C.N. Brown, D.M. Kaplan
Energy Loss versus Shadowing in the Drell-Yan Reaction on Nuclei
43 pages including 17 figures
Phys.Rev. C65 (2002) 025203
10.1103/PhysRevC.65.025203
null
hep-ph nucl-th
null
We present a new analysis of the E772 and E866 experiments on the nuclear dependence of Drell-Yan (DY) lepton pair production resulting from the bombardment of $^2H$, Be, C, Ca, Fe, and W targets by 800 GeV/c protons at Fermilab. We employ a light-cone formulation of the DY reaction in the rest frame of the nucleus, where the dimuons detected at small values of Bjorken x_2 << 1 may be considered to originate from the decay of a heavy photon radiated from an incident quark in a bremsstrahlung process. We infer the energy loss of the quark by examining the suppression of the nuclear-dependent DY ratios seen as a function of projectile momentum fraction x_1 and dimuon mass M. Shadowing, which also leads to nuclear suppression of dimuons, is calculated within the same approach employing the results of phenomenological fits to deep inelastic scattering data from HERA. The analysis yields -dE/dz =2.73 +/- 0.37 +/- 0.5 GeV/fm for the rate of quark energy loss per unit path length, a value consistent with theoretical expectations including the effects of the inelastic interaction of the incident proton at the surface of the nucleus. This is the first observation of a nonzero energy loss effect in such experiments.
[ { "created": "Fri, 18 May 2001 21:59:08 GMT", "version": "v1" }, { "created": "Sun, 27 May 2001 13:04:15 GMT", "version": "v2" } ]
2009-11-07
[ [ "Johnson", "M. B.", "" ], [ "Kopeliovich", "B. Z.", "" ], [ "Potashnikova", "I. K.", "" ], [ "McGaughey", "P. L.", "" ], [ "Moss", "J. M.", "" ], [ "Peng", "J. C.", "" ], [ "Garvey", "G.", "" ], [ "Leitch", "M.", "" ], [ "Brown", "C. N.", "" ], [ "Kaplan", "D. M.", "" ] ]
We present a new analysis of the E772 and E866 experiments on the nuclear dependence of Drell-Yan (DY) lepton pair production resulting from the bombardment of $^2H$, Be, C, Ca, Fe, and W targets by 800 GeV/c protons at Fermilab. We employ a light-cone formulation of the DY reaction in the rest frame of the nucleus, where the dimuons detected at small values of Bjorken x_2 << 1 may be considered to originate from the decay of a heavy photon radiated from an incident quark in a bremsstrahlung process. We infer the energy loss of the quark by examining the suppression of the nuclear-dependent DY ratios seen as a function of projectile momentum fraction x_1 and dimuon mass M. Shadowing, which also leads to nuclear suppression of dimuons, is calculated within the same approach employing the results of phenomenological fits to deep inelastic scattering data from HERA. The analysis yields -dE/dz =2.73 +/- 0.37 +/- 0.5 GeV/fm for the rate of quark energy loss per unit path length, a value consistent with theoretical expectations including the effects of the inelastic interaction of the incident proton at the surface of the nucleus. This is the first observation of a nonzero energy loss effect in such experiments.
hep-ph/9308339
null
A. Djouadi
New Fermions at e$^+$e$^-$ Colliders: I. Production and Decay
21 pages (no figures), Preprint UdeM-LPN-TH-93-157
Z. Phys. C63 (1994) 317-326
10.1007/BF01411024
null
hep-ph
null
We analyze the production in $e^+e^-$ collisions of new heavy fermions stemming from extensions of the Standard Model. We write down the most general expression for the production of two heavy fermions and their subsequent decays, allowing for the polarization of the e$^+$e$^-$ initial state and taking into account the final polarization of the fermions. We then discuss the various decay modes including cascade and three body decays, and the production mechanisms, both pair production and single production in association with ordinary fermions.
[ { "created": "Wed, 25 Aug 1993 20:21:15 GMT", "version": "v1" } ]
2009-10-22
[ [ "Djouadi", "A.", "" ] ]
We analyze the production in $e^+e^-$ collisions of new heavy fermions stemming from extensions of the Standard Model. We write down the most general expression for the production of two heavy fermions and their subsequent decays, allowing for the polarization of the e$^+$e$^-$ initial state and taking into account the final polarization of the fermions. We then discuss the various decay modes including cascade and three body decays, and the production mechanisms, both pair production and single production in association with ordinary fermions.
hep-ph/0702151
Guy Engelhard
Guy Engelhard, Yuval Grossman, Yosef Nir
Relating leptogenesis parameters to light neutrino masses
5 pages, 1 figure
JHEP 0707:029,2007
10.1088/1126-6708/2007/07/029
null
hep-ph
null
We obtain model independent relations among neutrino masses and leptogenesis parameters. We find exact relations that involve the CP asymmetries $\epsilon_{N_\alpha}$, the washout parameters $\tilde m_\alpha$ and $\theta_{\alpha\beta}$, and the neutrino masses $m_i$ and $M_\alpha$, as well as powerful inequalities that involve just $\tilde m_\alpha$ and $m_i$. We prove that the Yukawa interactions of at least two of the heavy singlet neutrinos are in the strong washout region ($\tilde m_\alpha\gg10^{-3} eV$).
[ { "created": "Thu, 15 Feb 2007 10:27:33 GMT", "version": "v1" } ]
2010-02-03
[ [ "Engelhard", "Guy", "" ], [ "Grossman", "Yuval", "" ], [ "Nir", "Yosef", "" ] ]
We obtain model independent relations among neutrino masses and leptogenesis parameters. We find exact relations that involve the CP asymmetries $\epsilon_{N_\alpha}$, the washout parameters $\tilde m_\alpha$ and $\theta_{\alpha\beta}$, and the neutrino masses $m_i$ and $M_\alpha$, as well as powerful inequalities that involve just $\tilde m_\alpha$ and $m_i$. We prove that the Yukawa interactions of at least two of the heavy singlet neutrinos are in the strong washout region ($\tilde m_\alpha\gg10^{-3} eV$).
hep-ph/0208267
Ralf Hofmann
Ralf Hofmann
The curvaton as a Bose-Einstein condensate of chiral pseudo Nambu-Goldstone bosons
19 pages, 5 figures, Section 1 deleted, minor text reformulations, changes in Eqs. (18), (51), (52), (54), and (65), Figs. 3,4, and 5 changed, 2 references added
Nucl.Phys. B740 (2006) 195-211
10.1016/j.nuclphysb.2006.02.002
MPI-PhT 2002-41
hep-ph
null
Explaining cosmic inflation by the effective dynamics of an $SU(N_C)$ pure gauge theory of scale $\La\sim 10^{-6} M_p$ is lacking an explanation of the (Gaussian) spatial curvature perturbations needed to seed the formation of large-scale structure after inflation. In this work it is demonstrated how fundamentally charged fermions of mass $m_F\sim 10^{-12} \La$, whose approximate chiral symmetry is spontaneously broken during inflation, can cure this shortcoming. The associated gas of weakly interacting pseudo Nambu-Goldstone bosons (PNGB) undergoes Bose-Einstein (BE) condensation well before the end of inflation. This causes the occurence of condensed light scalar fields effectively acting as a curvaton. Fermions may also be charged under a gauge group $G$ with a weak coupling $g$. Since fermions charged under $SU(N_C)$ are confined after inflation the decay of Nambu-Goldstone bosons, which reside in the condensates and in the PNGB radiation generated at reheating, is mainly into fermions {\sl solely} charged under $G$. The associated decay rate $\Gamma$ is estimated using PCAC and large $N_C$ counting. PNGB decay takes place during radiation domination after cosmological scales have entered the horizon. Neglecting the effects of the spontaneous breaking of G induced by the BE condensation, it is demonstrated that the observed spectrum of spatial curvature perturbations $P^{1/2}_\xi\sim 5\times 10^{-5}$ is compatible with $g\sim 10^{-3}$, a ratio $r_{\tiny{dec}}\sim 10^{-4}$ of curvaton to radiation energy at PNGB decay, and a curvaton effective equation of state $p_{\tiny{curv}}=-0.9 \rho_{\tiny{curv}}$.
[ { "created": "Thu, 29 Aug 2002 11:36:44 GMT", "version": "v1" }, { "created": "Mon, 22 Sep 2003 15:04:30 GMT", "version": "v2" } ]
2015-06-25
[ [ "Hofmann", "Ralf", "" ] ]
Explaining cosmic inflation by the effective dynamics of an $SU(N_C)$ pure gauge theory of scale $\La\sim 10^{-6} M_p$ is lacking an explanation of the (Gaussian) spatial curvature perturbations needed to seed the formation of large-scale structure after inflation. In this work it is demonstrated how fundamentally charged fermions of mass $m_F\sim 10^{-12} \La$, whose approximate chiral symmetry is spontaneously broken during inflation, can cure this shortcoming. The associated gas of weakly interacting pseudo Nambu-Goldstone bosons (PNGB) undergoes Bose-Einstein (BE) condensation well before the end of inflation. This causes the occurence of condensed light scalar fields effectively acting as a curvaton. Fermions may also be charged under a gauge group $G$ with a weak coupling $g$. Since fermions charged under $SU(N_C)$ are confined after inflation the decay of Nambu-Goldstone bosons, which reside in the condensates and in the PNGB radiation generated at reheating, is mainly into fermions {\sl solely} charged under $G$. The associated decay rate $\Gamma$ is estimated using PCAC and large $N_C$ counting. PNGB decay takes place during radiation domination after cosmological scales have entered the horizon. Neglecting the effects of the spontaneous breaking of G induced by the BE condensation, it is demonstrated that the observed spectrum of spatial curvature perturbations $P^{1/2}_\xi\sim 5\times 10^{-5}$ is compatible with $g\sim 10^{-3}$, a ratio $r_{\tiny{dec}}\sim 10^{-4}$ of curvaton to radiation energy at PNGB decay, and a curvaton effective equation of state $p_{\tiny{curv}}=-0.9 \rho_{\tiny{curv}}$.
hep-ph/0111402
Ismd31
Nicolas Borghini, Phuong Mai Dinh, Jean-Yves Ollitrault
Thermalization and elliptic flow at RHIC
6 pages, talk given at XXXI International Symposium on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. URL http://ismd31.ccnu.edu.cn/
null
null
null
hep-ph
null
We discuss signatures of thermalisation in heavy ion collisions based on elliptic flow. We then propose a new method to analyse elliptic flow, based on multiparticle azimuthal correlations. This method allows one to test quantitatively the collective behaviour of the interacting system.
[ { "created": "Thu, 29 Nov 2001 11:19:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Borghini", "Nicolas", "" ], [ "Dinh", "Phuong Mai", "" ], [ "Ollitrault", "Jean-Yves", "" ] ]
We discuss signatures of thermalisation in heavy ion collisions based on elliptic flow. We then propose a new method to analyse elliptic flow, based on multiparticle azimuthal correlations. This method allows one to test quantitatively the collective behaviour of the interacting system.
hep-ph/0607190
Ernest Ma
Ernest Ma (UC Riverside)
Suitability of A_4 as a Family Symmetry in Grand Unification
6 pages, no figure
Mod.Phys.Lett.A21:2931-2936,2006
10.1142/S0217732306022262
UCRHEP-T418 (July 2006)
hep-ph
null
In the recent successful applications of the non-Abelian discrete symmetry A_4 to the tribimaximal mixing of neutrinos, lepton doublets and singlets do not transform in the same way. It appears thus to be unsuitable as a family symmetry in grand unification. A simple resolution of this dilemma is proposed.
[ { "created": "Mon, 17 Jul 2006 15:30:47 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
In the recent successful applications of the non-Abelian discrete symmetry A_4 to the tribimaximal mixing of neutrinos, lepton doublets and singlets do not transform in the same way. It appears thus to be unsuitable as a family symmetry in grand unification. A simple resolution of this dilemma is proposed.
2210.04270
Xiao-Dong Ma
Yi Liao and Xiao-Dong Ma
One-loop Matching of Scotogenic Model onto Standard Model Effective Field Theory up to Dimension 7
28 pages, 2 figures, matched with the published version in JHEP
null
10.1007/JHEP12(2022)053
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The scotogenic neutrino seesaw model is a minimal extension of the standard model with three $\mathbb{Z}_2$-odd right-handed singlet fermions $N$ and one $\mathbb{Z}_2$-odd Higgs doublet $\eta$ that can accommodate the tiny neutrino mass and provide a dark matter candidate in a unified picture. Due to lack of experimental signatures for electroweak scale new physics, it is appealing to assume these new particles are well above the electroweak scale and take the effective field theory approach to study their effects on low energy observables. In this work we apply the recently developed functional matching formalism to the one-loop matching of the model onto the standard model effective field theory up to dimension seven for the case when all new states $N$ and $\eta$ are heavy to be integrated out. This is a realistic example which has no tree-level matching due to the $\mathbb{Z}_2$ symmetry. Using the matching results, we analyze their phenomenological implications for several physical processes, including the lepton number violating effect, the CDF $W$ mass excess, and the lepton flavor violating decays like $\mu\to e\gamma$ and $\mu\to 3e$.
[ { "created": "Sun, 9 Oct 2022 14:05:17 GMT", "version": "v1" }, { "created": "Sat, 3 Dec 2022 02:38:52 GMT", "version": "v2" } ]
2022-12-28
[ [ "Liao", "Yi", "" ], [ "Ma", "Xiao-Dong", "" ] ]
The scotogenic neutrino seesaw model is a minimal extension of the standard model with three $\mathbb{Z}_2$-odd right-handed singlet fermions $N$ and one $\mathbb{Z}_2$-odd Higgs doublet $\eta$ that can accommodate the tiny neutrino mass and provide a dark matter candidate in a unified picture. Due to lack of experimental signatures for electroweak scale new physics, it is appealing to assume these new particles are well above the electroweak scale and take the effective field theory approach to study their effects on low energy observables. In this work we apply the recently developed functional matching formalism to the one-loop matching of the model onto the standard model effective field theory up to dimension seven for the case when all new states $N$ and $\eta$ are heavy to be integrated out. This is a realistic example which has no tree-level matching due to the $\mathbb{Z}_2$ symmetry. Using the matching results, we analyze their phenomenological implications for several physical processes, including the lepton number violating effect, the CDF $W$ mass excess, and the lepton flavor violating decays like $\mu\to e\gamma$ and $\mu\to 3e$.
hep-ph/0303020
Stefan Leupold
Stefan Leupold (Giessen U., Germany)
Rho meson properties from combining QCD-based models
16 pages, 1 figure, Revtex4
Nucl.Phys. A743 (2004) 283-302
10.1016/j.nuclphysa.2004.08.005
null
hep-ph
null
Aiming at the calculation of the properties of rho-mesons, non-perturbative QCD-based methods are discussed concerning their potentials as well as their short-comings. The latter are overcome by combining these techniques. The utilized methods are (i) the chiral constituent quark model deduced from the instanton vacuum model and large-N_c arguments, (ii) chiral perturbation theory unitarized by the inverse amplitude method and (iii) QCD sum rules. Advantages of the combination of these methods are especially the absence of un-physical quark-production thresholds and parameter-free results. Already in the chiral limit and in leading order in 1/N_c one obtains a reasonable result for the mass of the rho-meson, namely m_rho = 790 \pm 30 MeV. Using the KSFR relation the universality of the rho-meson coupling is recovered. The latter is found to be g = 6.0 \pm 0.3.
[ { "created": "Tue, 4 Mar 2003 15:15:59 GMT", "version": "v1" } ]
2009-11-10
[ [ "Leupold", "Stefan", "", "Giessen U., Germany" ] ]
Aiming at the calculation of the properties of rho-mesons, non-perturbative QCD-based methods are discussed concerning their potentials as well as their short-comings. The latter are overcome by combining these techniques. The utilized methods are (i) the chiral constituent quark model deduced from the instanton vacuum model and large-N_c arguments, (ii) chiral perturbation theory unitarized by the inverse amplitude method and (iii) QCD sum rules. Advantages of the combination of these methods are especially the absence of un-physical quark-production thresholds and parameter-free results. Already in the chiral limit and in leading order in 1/N_c one obtains a reasonable result for the mass of the rho-meson, namely m_rho = 790 \pm 30 MeV. Using the KSFR relation the universality of the rho-meson coupling is recovered. The latter is found to be g = 6.0 \pm 0.3.
hep-ph/0307147
J. -Alexis Rodriguez L.
R. Martinez, N. Poveda and J.-Alexis Rodriguez
The upper bound of the lightest Higgs boson in a supersymmetric $SU(3)_L \otimes U(1)_X$ gauge model
Universidad Nacional de Colombia, 14 pages, 2 figures, RevTeX. Typos corrected. Version be published in Physical Review D
null
10.1103/PhysRevD.69.075013
null
hep-ph
null
A supersymmetric version of the $SU(3)_L \otimes U(1)_X$ gauge model is presented. The model is embedded in a $SU(6)_L \otimes U(1)_X$ gauge group and it has been built up completely quiral anomaly free and without any exotic charges in the fermionic content. The Minimal Supersymmetric Standard Model can be seen as an effective theory of this larger symmetry. We analyze how the spectrum of the new model can shift the upper bound on the CP-even Higgs boson and we find that it can be moved up to 143 GeV.
[ { "created": "Thu, 10 Jul 2003 16:42:14 GMT", "version": "v1" }, { "created": "Thu, 11 Sep 2003 04:01:34 GMT", "version": "v2" }, { "created": "Tue, 17 Feb 2004 12:41:30 GMT", "version": "v3" } ]
2009-11-10
[ [ "Martinez", "R.", "" ], [ "Poveda", "N.", "" ], [ "Rodriguez", "J. -Alexis", "" ] ]
A supersymmetric version of the $SU(3)_L \otimes U(1)_X$ gauge model is presented. The model is embedded in a $SU(6)_L \otimes U(1)_X$ gauge group and it has been built up completely quiral anomaly free and without any exotic charges in the fermionic content. The Minimal Supersymmetric Standard Model can be seen as an effective theory of this larger symmetry. We analyze how the spectrum of the new model can shift the upper bound on the CP-even Higgs boson and we find that it can be moved up to 143 GeV.
1407.5342
Peter Winslow
Stefano Profumo, Michael J. Ramsey-Musolf, Carroll L. Wainwright, Peter Winslow
Singlet-Catalyzed Electroweak Phase Transitions and Precision Higgs Studies
12 pages, 4 figures. Further discussion added on possible impact of future collider options including HL-LHC, ILC, TLEP, CEPC, VHE-LHC, and SppC. Submitted to PRD
Phys. Rev. D 91, 035018 (2015)
10.1103/PhysRevD.91.035018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We update the phenomenology of gauge singlet extensions of the Standard Model scalar sector and their implications for the electroweak phase transition. Considering the introduction of one real scalar singlet to the scalar potential, we analyze present constraints on the potential parameters from Higgs coupling measurements at the Large Hadron Collider (LHC) and electroweak precision observables for the kinematic regime in which no new scalar decay modes arise. We then show how future precision measurements of Higgs boson signal strengths and Higgs self-coupling could probe the scalar potential parameter space associated with a strong first-order electroweak phase transition. We illustrate using benchmark precision for several future collider options, including the High Luminosity LHC (HL-LHC), the International Linear Collider (ILC), TLEP, China Electron Positron Collider (CEPC), and a 100 TeV proton-proton collider, such as the Very High Energy LHC (VHE-LHC) or the Super proton-proton Collider (SPPC). For the regions of parameter space leading to a strong first order electroweak phase transition, we find that there exists considerable potential for observable deviations from purely Standard Model Higgs properties at these prospective future colliders.
[ { "created": "Sun, 20 Jul 2014 21:55:23 GMT", "version": "v1" }, { "created": "Thu, 4 Sep 2014 20:58:16 GMT", "version": "v2" } ]
2015-03-05
[ [ "Profumo", "Stefano", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Wainwright", "Carroll L.", "" ], [ "Winslow", "Peter", "" ] ]
We update the phenomenology of gauge singlet extensions of the Standard Model scalar sector and their implications for the electroweak phase transition. Considering the introduction of one real scalar singlet to the scalar potential, we analyze present constraints on the potential parameters from Higgs coupling measurements at the Large Hadron Collider (LHC) and electroweak precision observables for the kinematic regime in which no new scalar decay modes arise. We then show how future precision measurements of Higgs boson signal strengths and Higgs self-coupling could probe the scalar potential parameter space associated with a strong first-order electroweak phase transition. We illustrate using benchmark precision for several future collider options, including the High Luminosity LHC (HL-LHC), the International Linear Collider (ILC), TLEP, China Electron Positron Collider (CEPC), and a 100 TeV proton-proton collider, such as the Very High Energy LHC (VHE-LHC) or the Super proton-proton Collider (SPPC). For the regions of parameter space leading to a strong first order electroweak phase transition, we find that there exists considerable potential for observable deviations from purely Standard Model Higgs properties at these prospective future colliders.
1512.07561
Jorge Casalderrey-Solana
Jorge Casalderrey-Solana, Daniel Pablos and Konrad Tywoniuk
Jet formation and interference in a thin QCD medium
33 pages
null
null
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In heavy-ion collisions, an abundant production of high-energy QCD jets allows to study how these multiparticle sprays are modified as they pass through the quark-gluon plasma. In order to shed new light on this process, we compute the inclusive two-gluon rate off a hard quark propagating through a color deconfined medium at first order in medium opacity. We explicitly impose an energy ordering of the two emitted gluons, such that the "hard" gluon can be thought of as belonging to the jet substructure while the other is a "soft" emission (which can be collinear or medium-induced). Our analysis focusses on two specific limits that clarify the modification of the additional angle- and formation time-ordering of splittings. In one limit, the formation time of the "hard" gluon is short compared to the "soft" gluon formation time, leading to a probabilistic formula for production of and subsequent radiation off a quark-gluon antenna. In the other limit, the ordering of formation is reverted, which automatically leads to the fact that the jet substructure is resolved by the medium. We observe in this case a characteristic delay: the jet radiates as one color current (quark) up to the formation of the "hard" gluon, at which point we observe the onset of radiation of the new color current (gluon). Our computation supports a picture in which the in-medium jet dynamics are described as a collection of subsequent antennas which are resolved by the medium according to their transverse extent.
[ { "created": "Wed, 23 Dec 2015 17:53:47 GMT", "version": "v1" } ]
2015-12-24
[ [ "Casalderrey-Solana", "Jorge", "" ], [ "Pablos", "Daniel", "" ], [ "Tywoniuk", "Konrad", "" ] ]
In heavy-ion collisions, an abundant production of high-energy QCD jets allows to study how these multiparticle sprays are modified as they pass through the quark-gluon plasma. In order to shed new light on this process, we compute the inclusive two-gluon rate off a hard quark propagating through a color deconfined medium at first order in medium opacity. We explicitly impose an energy ordering of the two emitted gluons, such that the "hard" gluon can be thought of as belonging to the jet substructure while the other is a "soft" emission (which can be collinear or medium-induced). Our analysis focusses on two specific limits that clarify the modification of the additional angle- and formation time-ordering of splittings. In one limit, the formation time of the "hard" gluon is short compared to the "soft" gluon formation time, leading to a probabilistic formula for production of and subsequent radiation off a quark-gluon antenna. In the other limit, the ordering of formation is reverted, which automatically leads to the fact that the jet substructure is resolved by the medium. We observe in this case a characteristic delay: the jet radiates as one color current (quark) up to the formation of the "hard" gluon, at which point we observe the onset of radiation of the new color current (gluon). Our computation supports a picture in which the in-medium jet dynamics are described as a collection of subsequent antennas which are resolved by the medium according to their transverse extent.
hep-ph/0403270
Peter Renkel
Ehud Duchovni, Eugene Prosso and Peter Renkel
A New Algorithm for Inclusive Search of SUSY Signal
18 pages, 9 figures, 1 Appendix
Eur.Phys.J.C40N5:43-49,2005
10.1140/epjcd/s2005-02-005-1
WIC/07/04-MAR-DPP
hep-ph hep-ex
null
A new algorithm designed to reduce the model dependence in future SUSY searches at the LHC is described. This algorithm can dynamically adapt itself to a wide range of possible SUSY final states thus reducing the need for detailed model-driven analysis. Preliminary study of its performance on simulated MSSM, GMSB and AMSB final states is described, and a comparison with traditional search procedures, whenever available, is performed.
[ { "created": "Thu, 25 Mar 2004 20:33:19 GMT", "version": "v1" }, { "created": "Thu, 29 Apr 2004 15:03:23 GMT", "version": "v2" } ]
2011-09-13
[ [ "Duchovni", "Ehud", "" ], [ "Prosso", "Eugene", "" ], [ "Renkel", "Peter", "" ] ]
A new algorithm designed to reduce the model dependence in future SUSY searches at the LHC is described. This algorithm can dynamically adapt itself to a wide range of possible SUSY final states thus reducing the need for detailed model-driven analysis. Preliminary study of its performance on simulated MSSM, GMSB and AMSB final states is described, and a comparison with traditional search procedures, whenever available, is performed.
1009.5391
Keith Hamilton
Keith Hamilton
A positive-weight next-to-leading order simulation of weak boson pair production
32 pages, 9 figures; v2 references added; v3 commented on singly resonant contributions and damping factors
JHEP 1101:009,2011
10.1007/JHEP01(2011)009
MCnet/10/18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we describe simulations of ZZ, WZ and WW production based on the positive weight next-to-leading-order matching scheme, Powheg, in the Herwig++ event generator. Building on earlier efforts within the Herwig++ framework, the simulation includes a full description of truncated showering effects, required to correctly model soft, wide angle, emissions in angular-ordered parton showers. We utilize simple relations among each of the diboson cross sections, holding to order alpha_S, in constructing the simulation. Spin correlation effects are also included in the decays of the vector bosons at the tree order. A large part of this work is concerned with a full and thorough validation of the simulations through comparisons with alternative methods and calculations.
[ { "created": "Mon, 27 Sep 2010 20:20:59 GMT", "version": "v1" }, { "created": "Sat, 2 Oct 2010 09:00:08 GMT", "version": "v2" }, { "created": "Fri, 26 Nov 2010 16:20:52 GMT", "version": "v3" } ]
2011-03-07
[ [ "Hamilton", "Keith", "" ] ]
In this article we describe simulations of ZZ, WZ and WW production based on the positive weight next-to-leading-order matching scheme, Powheg, in the Herwig++ event generator. Building on earlier efforts within the Herwig++ framework, the simulation includes a full description of truncated showering effects, required to correctly model soft, wide angle, emissions in angular-ordered parton showers. We utilize simple relations among each of the diboson cross sections, holding to order alpha_S, in constructing the simulation. Spin correlation effects are also included in the decays of the vector bosons at the tree order. A large part of this work is concerned with a full and thorough validation of the simulations through comparisons with alternative methods and calculations.
1112.5910
Zhi-Gang Wang
Zhi-Gang Wang
Analysis of the light-flavor scalar and axial-vector diquark states with QCD sum rules
10 pages, 5 figures, revised version
Commun. Theor. Phys. 59 (2013) 451-456
10.1088/0253-6102/59/4/11
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we study the light-flavor scalar and axial-vector diquark states in the vacuum and in the nuclear matter using the QCD sum rules in an systematic way, and make reasonable predictions for their masses in the vacuum and in the nuclear matter.
[ { "created": "Tue, 27 Dec 2011 02:57:45 GMT", "version": "v1" }, { "created": "Thu, 12 Apr 2012 07:56:23 GMT", "version": "v2" } ]
2017-01-25
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we study the light-flavor scalar and axial-vector diquark states in the vacuum and in the nuclear matter using the QCD sum rules in an systematic way, and make reasonable predictions for their masses in the vacuum and in the nuclear matter.
1808.05815
Dharmesh Rathaud
D. P. Rathaud and Ajay Kumar Rai
Interaction and Identification of the Meson-Baryon molecules
19 pages, 7 Figures, 10 Tables, Comments and Suggestions are invited
Indian J Physics (2021)
10.1007/s12648-020-01954-6
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The challenges with the molecular model of the multiquark systems are the identification of the hadronic molecules and the interaction between two color neutral hadrons. We study the di-hadronic molecular systems with proposed interaction potential as s-wave one boson exchange potential along with Screen Yukawa-like potential, and arrived with the proposal that within hadronic molecule the two color neutral hadrons experience the dipole-like interaction. The present study is the continuation of our previous study \cite{arxiv-Rathaud-penta}. With the proposed interaction potential, the mass spectra of $\Sigma_{s}K^{*}$, $\Sigma_{c}K^{*}$, $\Sigma_{b}K^{*}$, $\Sigma_{s}D^{*}$, $\Sigma_{c}D^{*}$, $\Sigma_{b}D^{*}$, $\Sigma_{s}B^{*}$, $\Sigma_{c}B^{*}$, $\Sigma_{b}B^{*}$, $\Xi_{s}K^{*}$, $\Xi_{c}K^{*}$, $\Xi_{b}K^{*}$, $\Xi_{s}D^{*}$, $\Xi_{c}D^{*}$, $\Xi_{b}D^{*}$, $\Xi_{s}B^{*}$, $\Xi_{c}B^{*}$, $\Xi_{b}B^{*}$ meson-baryon molecules are predicted. The Weinberg compositeness theorem which provides clue for the compositeness of the state is used for determination of the scattering length and effective range. The present study predict $P_{c}(4450)$ pentaquark sate as $\Sigma_{c}D^{*}$ molecule with $I(J^{P})=\frac{1}{2}(\frac{3}{2}^{-})$. The formalism also predicts some very interesting open as well as hidden flavour near threshold molecular pentaquark states.
[ { "created": "Fri, 17 Aug 2018 10:05:26 GMT", "version": "v1" } ]
2021-02-08
[ [ "Rathaud", "D. P.", "" ], [ "Rai", "Ajay Kumar", "" ] ]
The challenges with the molecular model of the multiquark systems are the identification of the hadronic molecules and the interaction between two color neutral hadrons. We study the di-hadronic molecular systems with proposed interaction potential as s-wave one boson exchange potential along with Screen Yukawa-like potential, and arrived with the proposal that within hadronic molecule the two color neutral hadrons experience the dipole-like interaction. The present study is the continuation of our previous study \cite{arxiv-Rathaud-penta}. With the proposed interaction potential, the mass spectra of $\Sigma_{s}K^{*}$, $\Sigma_{c}K^{*}$, $\Sigma_{b}K^{*}$, $\Sigma_{s}D^{*}$, $\Sigma_{c}D^{*}$, $\Sigma_{b}D^{*}$, $\Sigma_{s}B^{*}$, $\Sigma_{c}B^{*}$, $\Sigma_{b}B^{*}$, $\Xi_{s}K^{*}$, $\Xi_{c}K^{*}$, $\Xi_{b}K^{*}$, $\Xi_{s}D^{*}$, $\Xi_{c}D^{*}$, $\Xi_{b}D^{*}$, $\Xi_{s}B^{*}$, $\Xi_{c}B^{*}$, $\Xi_{b}B^{*}$ meson-baryon molecules are predicted. The Weinberg compositeness theorem which provides clue for the compositeness of the state is used for determination of the scattering length and effective range. The present study predict $P_{c}(4450)$ pentaquark sate as $\Sigma_{c}D^{*}$ molecule with $I(J^{P})=\frac{1}{2}(\frac{3}{2}^{-})$. The formalism also predicts some very interesting open as well as hidden flavour near threshold molecular pentaquark states.
2306.03893
Sebastian Zell
Arthur Poisson, Inar Timiryasov, Sebastian Zell
Critical Points in Palatini Higgs Inflation with Small Non-Minimal Coupling
42 pages, 11 figures, 1 appendix
null
null
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate inflation driven by the Higgs boson in the Palatini formulation of General Relativity. Our analysis primarily focuses on a small non-minimal coupling of the Higgs field to gravity in the range $0<\xi\lesssim 1$. We incorporate the renormalization group running of the relevant parameters as computed within the Standard Model and allow for small corrections. In addition to $\xi$, our model features two tunable parameters: the low-energy value of the top Yukawa coupling and an effective jump of the Higgs self-interaction. Our results indicate that critical points leading to a large enhancement of the power spectrum can be produced. However, the observed amplitude of perturbations in the CMB cannot be matched within this setting. On the one hand, this makes it difficult to generate a sizable abundance of primordial black holes. On the other hand, our finding can be viewed as further evidence that Palatini Higgs inflation has favourable high-energy properties due to robustness against quantum corrections.
[ { "created": "Tue, 6 Jun 2023 17:53:38 GMT", "version": "v1" } ]
2023-06-07
[ [ "Poisson", "Arthur", "" ], [ "Timiryasov", "Inar", "" ], [ "Zell", "Sebastian", "" ] ]
We investigate inflation driven by the Higgs boson in the Palatini formulation of General Relativity. Our analysis primarily focuses on a small non-minimal coupling of the Higgs field to gravity in the range $0<\xi\lesssim 1$. We incorporate the renormalization group running of the relevant parameters as computed within the Standard Model and allow for small corrections. In addition to $\xi$, our model features two tunable parameters: the low-energy value of the top Yukawa coupling and an effective jump of the Higgs self-interaction. Our results indicate that critical points leading to a large enhancement of the power spectrum can be produced. However, the observed amplitude of perturbations in the CMB cannot be matched within this setting. On the one hand, this makes it difficult to generate a sizable abundance of primordial black holes. On the other hand, our finding can be viewed as further evidence that Palatini Higgs inflation has favourable high-energy properties due to robustness against quantum corrections.
hep-ph/0003282
Mariusz Sadzikowski
Mariusz Sadzikowski and Wojciech Broniowski
Non-uniform chiral phase in effective chiral quark models
null
Phys.Lett. B488 (2000) 63-67
10.1016/S0370-2693(00)00830-3
null
hep-ph
null
We analyze the phase diagram in effective chiral quark models (the Nambu-Jona-Lasinio model, the sigma-model with quarks) and show that at the mean-field level a phase with a periodically-modulated chiral fields separates the usual phases with broken and restored chiral symmetry. A possible signal of such a phase is the production of multipion jets travelling in opposite directions, with individual pions having momenta of the order of several hundred MeV. This signal can be interpreted in terms of disoriented chiral condensates.
[ { "created": "Wed, 29 Mar 2000 10:20:20 GMT", "version": "v1" } ]
2009-10-31
[ [ "Sadzikowski", "Mariusz", "" ], [ "Broniowski", "Wojciech", "" ] ]
We analyze the phase diagram in effective chiral quark models (the Nambu-Jona-Lasinio model, the sigma-model with quarks) and show that at the mean-field level a phase with a periodically-modulated chiral fields separates the usual phases with broken and restored chiral symmetry. A possible signal of such a phase is the production of multipion jets travelling in opposite directions, with individual pions having momenta of the order of several hundred MeV. This signal can be interpreted in terms of disoriented chiral condensates.
hep-ph/0409235
Gary Prezeau
Gary Pr\'ezeau
Light neutrino and heavy particle exchange in $\nbb$-decay
4 pages
Phys.Lett. B633 (2006) 93-97
10.1016/j.physletb.2005.11.048
null
hep-ph
null
A simple and precise method is presented to compare contributions to neutrinoless double-beta decay ($\nbb$-decay) from heavy particle exchange and light Majorana neutrino exchange. This procedure makes no assumptions about the momentum transfer between the two nucleons involved in the $\nbb$-decay process. It is shown that for a general particle physics model, the characteristic $\nbb$-decay scale $> 4.4$ TeV when all the coupling constants are assumed to be natural and of ${\cal{O}}(1)$.
[ { "created": "Mon, 20 Sep 2004 20:24:31 GMT", "version": "v1" } ]
2016-08-16
[ [ "Prézeau", "Gary", "" ] ]
A simple and precise method is presented to compare contributions to neutrinoless double-beta decay ($\nbb$-decay) from heavy particle exchange and light Majorana neutrino exchange. This procedure makes no assumptions about the momentum transfer between the two nucleons involved in the $\nbb$-decay process. It is shown that for a general particle physics model, the characteristic $\nbb$-decay scale $> 4.4$ TeV when all the coupling constants are assumed to be natural and of ${\cal{O}}(1)$.
2203.02899
Zheng Li Wang
Zheng-Li Wang and Bing-Song Zou
Two dynamical generated $a_0$ resonances by interactions between vector mesons
arXiv admin note: substantial text overlap with arXiv:2107.14470
null
10.1140/epjc/s10052-022-10460-4
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We study dynamically generated $a_0$ resonances by interactions between vector mesons including their coupling to channels of pseudoscalar mesons within coupled-channel approach. Both vector and pseudoscalar mesons are considered as $t$-channel exchanged mesons for calculating interactions between vector mesons. Analogous to $a_0(980)$ as a $K\bar K-\pi\eta$ dynamically generated state, there is an $a_0(1710)$ as a coupled channel dynamically generated state near $K^*\bar{K}^*$ threshold. The channels involved are $\rho\phi,K^*\bar{K}^*,\rho\omega, K\bar{K},\pi\eta$. This $a_0$ mainly decays to $\rho\omega$, $\pi\eta$ and $K\bar{K}$. This pole is much tied to the coupled channel effect. If we turn off either $\rho\phi$ or $K^*\bar{K}^*$, the pole disappears. In addition, it is found that $a_0(1450)$ may also be dynamically generated by $\rho\omega$ interactions due to $\pi$ and $\eta$ exchange.
[ { "created": "Sun, 6 Mar 2022 07:57:33 GMT", "version": "v1" } ]
2022-06-22
[ [ "Wang", "Zheng-Li", "" ], [ "Zou", "Bing-Song", "" ] ]
We study dynamically generated $a_0$ resonances by interactions between vector mesons including their coupling to channels of pseudoscalar mesons within coupled-channel approach. Both vector and pseudoscalar mesons are considered as $t$-channel exchanged mesons for calculating interactions between vector mesons. Analogous to $a_0(980)$ as a $K\bar K-\pi\eta$ dynamically generated state, there is an $a_0(1710)$ as a coupled channel dynamically generated state near $K^*\bar{K}^*$ threshold. The channels involved are $\rho\phi,K^*\bar{K}^*,\rho\omega, K\bar{K},\pi\eta$. This $a_0$ mainly decays to $\rho\omega$, $\pi\eta$ and $K\bar{K}$. This pole is much tied to the coupled channel effect. If we turn off either $\rho\phi$ or $K^*\bar{K}^*$, the pole disappears. In addition, it is found that $a_0(1450)$ may also be dynamically generated by $\rho\omega$ interactions due to $\pi$ and $\eta$ exchange.
1904.04200
Darius Faroughy
Barry M. Dillon, Darius A. Faroughy, Jernej F. Kamenik
Uncovering latent jet substructure
8 pages, 3 figures; v2: matches published version. Additional clarifying comments added in sections I and II. Updated references
Phys. Rev. D 100, 056002 (2019)
10.1103/PhysRevD.100.056002
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply techniques from Bayesian generative statistical modeling to uncover hidden features in jet substructure observables that discriminate between different a priori unknown underlying short distance physical processes in multi-jet events. In particular, we use a mixed membership model known as Latent Dirichlet Allocation to build a data-driven unsupervised top-quark tagger and $t\bar t$ event classifier. We compare our proposal to existing traditional and machine learning approaches to top jet tagging. Finally, employing a toy vector-scalar boson model as a benchmark, we demonstrate the potential for discovering New Physics signatures in multi-jet events in a model independent and unsupervised way.
[ { "created": "Mon, 8 Apr 2019 17:17:46 GMT", "version": "v1" }, { "created": "Mon, 23 Sep 2019 10:08:45 GMT", "version": "v2" } ]
2019-09-24
[ [ "Dillon", "Barry M.", "" ], [ "Faroughy", "Darius A.", "" ], [ "Kamenik", "Jernej F.", "" ] ]
We apply techniques from Bayesian generative statistical modeling to uncover hidden features in jet substructure observables that discriminate between different a priori unknown underlying short distance physical processes in multi-jet events. In particular, we use a mixed membership model known as Latent Dirichlet Allocation to build a data-driven unsupervised top-quark tagger and $t\bar t$ event classifier. We compare our proposal to existing traditional and machine learning approaches to top jet tagging. Finally, employing a toy vector-scalar boson model as a benchmark, we demonstrate the potential for discovering New Physics signatures in multi-jet events in a model independent and unsupervised way.
2207.13659
Loyd Waites III
Loyd Waites, Adrian Thompson, Adriana Bungau, Janet M. Conrad, Bhaskar Dutta, Wei-Chih Huang, Doojin Kim, Michael Shaevitz, and Joshua Spitz
Axion-Like Particle Production at Beam Dump Experiments with Distinct Nuclear Excitation Lines
8 pages including references, 4 figures, one table, 8 equations, PRL format
null
10.1103/PhysRevD.107.095010
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Searches for axion-like particles (ALPs) are motivated by the strong CP problem in particle physics and by unexplained dark matter in astrophysics. In this letter, we discuss novel ALP searches using monoenergetic nuclear de-excitation photons from a beam dump, using IsoDAR as an example. We show that IsoDAR can set limits that close a gap in traditional QCD axion searches using the ALP-photon coupling, as well as provide sensitivity to large regions of new parameter space in models where ALPs couple to nucleons and electrons. We also show how isotope decay-at-rest experiments may be designed to improve potential ALP production and optimize detection sensitivity.
[ { "created": "Wed, 27 Jul 2022 17:26:40 GMT", "version": "v1" }, { "created": "Tue, 16 Aug 2022 15:58:48 GMT", "version": "v2" }, { "created": "Wed, 26 Apr 2023 22:08:43 GMT", "version": "v3" }, { "created": "Thu, 25 May 2023 20:06:27 GMT", "version": "v4" } ]
2023-05-29
[ [ "Waites", "Loyd", "" ], [ "Thompson", "Adrian", "" ], [ "Bungau", "Adriana", "" ], [ "Conrad", "Janet M.", "" ], [ "Dutta", "Bhaskar", "" ], [ "Huang", "Wei-Chih", "" ], [ "Kim", "Doojin", "" ], [ "Shaevitz", "Michael", "" ], [ "Spitz", "Joshua", "" ] ]
Searches for axion-like particles (ALPs) are motivated by the strong CP problem in particle physics and by unexplained dark matter in astrophysics. In this letter, we discuss novel ALP searches using monoenergetic nuclear de-excitation photons from a beam dump, using IsoDAR as an example. We show that IsoDAR can set limits that close a gap in traditional QCD axion searches using the ALP-photon coupling, as well as provide sensitivity to large regions of new parameter space in models where ALPs couple to nucleons and electrons. We also show how isotope decay-at-rest experiments may be designed to improve potential ALP production and optimize detection sensitivity.
1801.00592
Stephan Narison
Stephan Narison (LUPM-CNRS Montpellier-FR)
QCD Parameters Correlations from Heavy Quarkonia
22 pages, 1 Table, 16 Figures. Extended version of talks presented at QCD 17 (Montpellier-FR) and HEPMAD 16/17 (Antananarivo-MG). New Addendum where more detailed discussions on the extraction of alpha_s from the M_\chi_0c(0b)-M_\eta_c(b) mass-splittings are given
null
10.1142/S0217751X18500458
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Correlations between the QCD coupling \alpha_s, the gluon condensate < \alpha_s G^2 >, and the c,b-quark running masses m_c,b in the MS-scheme are explicitly studied (for the first time) from the (axial-)vector and (pseudo)scalar charmonium and bottomium ratios of Laplace sum rules (LSR) evaluated at the \mu-subtraction stability point where PT @N2LO, N3LO and < \alpha_s G^2> @NLO corrections are included. Our results clarify the (apparent) discrepancies between different estimates of < \alpha_s G^2> from J/\psi sum rule but also shows the sensitivity of the sum rules on the choice of the \mu-subtraction scale which does not permit a high-precision estimate of m_c,b. We obtain from the (axial-)vector [resp. (pseudo)scalar] channels <\alpha_s G^2>=(8.5+- 3.0)> [resp. (6.34+-.39)] 10^-2 GeV^4, m_c(m_c)= 1256(30) [resp. 1266(16)] MeV and m_b(m_b)=4192(15) MeV. Combined with our recent determinations from vector channel, one obtains the average: m_c(m_c)= 1263(14) MeV and m_b(m_b) 4184(11) MeV. Adding our value of the gluon condensate with different previous estimates, we obtain the new sum rule average: <\alpha_s G^2>=(6.35+- 0.35) 10^-2 GeV^4. The mass-splittings M_\chi_0c(0b)-M_\eta_c(b) give @N2LO: \alpha_s(M_Z)=0.1183(19)(3) in good agreement with the world average (see more detailed discussions in the section: addendum). .
[ { "created": "Tue, 2 Jan 2018 10:02:53 GMT", "version": "v1" }, { "created": "Sun, 7 Jan 2018 22:56:32 GMT", "version": "v2" }, { "created": "Sun, 14 Jan 2018 11:33:20 GMT", "version": "v3" }, { "created": "Mon, 3 Dec 2018 15:49:47 GMT", "version": "v4" } ]
2018-12-04
[ [ "Narison", "Stephan", "", "LUPM-CNRS Montpellier-FR" ] ]
Correlations between the QCD coupling \alpha_s, the gluon condensate < \alpha_s G^2 >, and the c,b-quark running masses m_c,b in the MS-scheme are explicitly studied (for the first time) from the (axial-)vector and (pseudo)scalar charmonium and bottomium ratios of Laplace sum rules (LSR) evaluated at the \mu-subtraction stability point where PT @N2LO, N3LO and < \alpha_s G^2> @NLO corrections are included. Our results clarify the (apparent) discrepancies between different estimates of < \alpha_s G^2> from J/\psi sum rule but also shows the sensitivity of the sum rules on the choice of the \mu-subtraction scale which does not permit a high-precision estimate of m_c,b. We obtain from the (axial-)vector [resp. (pseudo)scalar] channels <\alpha_s G^2>=(8.5+- 3.0)> [resp. (6.34+-.39)] 10^-2 GeV^4, m_c(m_c)= 1256(30) [resp. 1266(16)] MeV and m_b(m_b)=4192(15) MeV. Combined with our recent determinations from vector channel, one obtains the average: m_c(m_c)= 1263(14) MeV and m_b(m_b) 4184(11) MeV. Adding our value of the gluon condensate with different previous estimates, we obtain the new sum rule average: <\alpha_s G^2>=(6.35+- 0.35) 10^-2 GeV^4. The mass-splittings M_\chi_0c(0b)-M_\eta_c(b) give @N2LO: \alpha_s(M_Z)=0.1183(19)(3) in good agreement with the world average (see more detailed discussions in the section: addendum). .
1409.2806
Pierre Sikivie
P. Sikivie
Axion Dark Matter Detection using Atomic Transitions
5 pages, 2 figures. An error of a factor 4 in the event rate is corrected
null
10.1103/PhysRevLett.113.201301
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.
[ { "created": "Tue, 9 Sep 2014 16:39:07 GMT", "version": "v1" }, { "created": "Sun, 31 May 2020 21:33:46 GMT", "version": "v2" } ]
2020-06-02
[ [ "Sikivie", "P.", "" ] ]
Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.
hep-ph/9610386
Christophe Royon
Ch. Royon
QCD dipole prediction for DIS and diffractive structure functions
4 pages, latex file, 2 figures Invited talk given at the 28th International Conference on High Energy Physics (ICHEP 96), 25-31 July 1996, Warsaw, Poland
null
10.1063/1.53627
null
hep-ph
null
The $F_{2}$, $F_{G}$, $R=F_{L}/F_{T}$ proton structure functions are derived in the QCD dipole picture of BFKL dynamics. We get a three parameter fit describing the 1994 H1 proton structure function $F_{2}$ data in the low $x$, moderate $Q^{2}$ range. Without any additional parameter, the gluon density and the longitudinal structure functions are predicted.The diffractive dissociation processes are also discussed, and a new prediction for the proton diffractive structure function is obtained.
[ { "created": "Thu, 17 Oct 1996 09:41:20 GMT", "version": "v1" } ]
2009-10-30
[ [ "Royon", "Ch.", "" ] ]
The $F_{2}$, $F_{G}$, $R=F_{L}/F_{T}$ proton structure functions are derived in the QCD dipole picture of BFKL dynamics. We get a three parameter fit describing the 1994 H1 proton structure function $F_{2}$ data in the low $x$, moderate $Q^{2}$ range. Without any additional parameter, the gluon density and the longitudinal structure functions are predicted.The diffractive dissociation processes are also discussed, and a new prediction for the proton diffractive structure function is obtained.
1811.10333
Jing-Juan Qi
Jing-Juan Qi, Zhen-Yang Wang, Xin-Heng Guo, Zhen-Hua Zhang
Study of localized $CP$ violation in $B^-\rightarrow \pi^- \pi^+\pi^-$ and the branching ratio of $B^-\rightarrow \sigma(600)\pi^-$ in the QCD factorization approach
arXiv admin note: substantial text overlap with arXiv:1811.02167
null
10.1016/j.nuclphysb.2019.114788
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, within the QCD factorization approach, we study the localized integrated $CP$ violation in the $B^-\rightarrow \pi^-\pi^+\pi^-$ decay and the branching fraction of the $B^-\rightarrow\sigma\pi^-$ decay. Both the resonance and nonresonance contributions are included when we study the localized $CP$ asymmetry in the $B^-\rightarrow \pi^-\pi^+\pi^-$ decay. The resonance contributions from the scalar $\sigma(600)$ and vector $\rho^0(770)$ mesons are included. For the $\sigma(600)$ meson, we apply both the Breit-Wigner and Bugg models to deal with its propagator, and obtain $\mathcal{B}(B^-\rightarrow \sigma(600)\pi^-)<1.67\times10^{-6}$ and $\mathcal{B}(B^-\rightarrow \sigma(600) \pi^-)<1.946\times10^{-5}$ in these two models, respectively. We find that there is no allowed divergence parameters $\rho_S$ and $\phi_S$ to satisfy the experimental data $\mathcal{A_{CP}}(\pi^-\pi^+\pi^-)=0.584\pm0.082\pm0.027\pm0.007$ in the region $m_{\pi^+\pi^- \mathrm{high}}^2>15$ $\mathrm{GeV}^2$ and $m_{\pi^+\pi^-\mathrm{low}}^2<0.4$ $\mathrm{GeV}^2$ and the upper limit of $\mathcal{B}(B^-\rightarrow \sigma(600)\pi^-)$ in the Breit-Wigner model, however, there exists the region $\rho_S\in[1.70,3.34]$ and $\phi_S \in [0.50,4.50]$ satisfying the data for $\mathcal{A_{CP}}(\pi^-\pi^+\pi^-)$ and the upper limit of $\mathcal{B}(B^-\rightarrow \sigma(600)\pi^-)$ in the Bugg model. This reveals that the Bugg model is more plausible than the Breit-Wigner model to describe the propagator of the $\sigma(600)$ meson even though the finite width effects are considered in both models. The large values of $\rho_S$ indicate that the contributions from weak annihilation and hard spectator scattering processes are both large, especially, the weak annihilation contribution should not be negleted for $B$ decays to final states including a scalar meson.
[ { "created": "Mon, 26 Nov 2018 12:46:41 GMT", "version": "v1" }, { "created": "Sun, 17 Nov 2019 01:35:07 GMT", "version": "v2" } ]
2019-11-19
[ [ "Qi", "Jing-Juan", "" ], [ "Wang", "Zhen-Yang", "" ], [ "Guo", "Xin-Heng", "" ], [ "Zhang", "Zhen-Hua", "" ] ]
In this work, within the QCD factorization approach, we study the localized integrated $CP$ violation in the $B^-\rightarrow \pi^-\pi^+\pi^-$ decay and the branching fraction of the $B^-\rightarrow\sigma\pi^-$ decay. Both the resonance and nonresonance contributions are included when we study the localized $CP$ asymmetry in the $B^-\rightarrow \pi^-\pi^+\pi^-$ decay. The resonance contributions from the scalar $\sigma(600)$ and vector $\rho^0(770)$ mesons are included. For the $\sigma(600)$ meson, we apply both the Breit-Wigner and Bugg models to deal with its propagator, and obtain $\mathcal{B}(B^-\rightarrow \sigma(600)\pi^-)<1.67\times10^{-6}$ and $\mathcal{B}(B^-\rightarrow \sigma(600) \pi^-)<1.946\times10^{-5}$ in these two models, respectively. We find that there is no allowed divergence parameters $\rho_S$ and $\phi_S$ to satisfy the experimental data $\mathcal{A_{CP}}(\pi^-\pi^+\pi^-)=0.584\pm0.082\pm0.027\pm0.007$ in the region $m_{\pi^+\pi^- \mathrm{high}}^2>15$ $\mathrm{GeV}^2$ and $m_{\pi^+\pi^-\mathrm{low}}^2<0.4$ $\mathrm{GeV}^2$ and the upper limit of $\mathcal{B}(B^-\rightarrow \sigma(600)\pi^-)$ in the Breit-Wigner model, however, there exists the region $\rho_S\in[1.70,3.34]$ and $\phi_S \in [0.50,4.50]$ satisfying the data for $\mathcal{A_{CP}}(\pi^-\pi^+\pi^-)$ and the upper limit of $\mathcal{B}(B^-\rightarrow \sigma(600)\pi^-)$ in the Bugg model. This reveals that the Bugg model is more plausible than the Breit-Wigner model to describe the propagator of the $\sigma(600)$ meson even though the finite width effects are considered in both models. The large values of $\rho_S$ indicate that the contributions from weak annihilation and hard spectator scattering processes are both large, especially, the weak annihilation contribution should not be negleted for $B$ decays to final states including a scalar meson.
1802.09403
Vincent Mathieu
JPAC Collaboration: V. Mathieu, J. Nys, C. Fern\'andez-Ram\'irez, A. Jackura, A. Pilloni, N. Sherrill, A. Szczepaniak and G. Fox
Vector Meson Photoproduction with a Linearly Polarized Beam
Code avalaible on the JPAC website: http://www.indiana.edu/~jpac/index.html
Phys. Rev. D 97, 094003 (2018)
10.1103/PhysRevD.97.094003
JLAB-THY-18-2650
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a model based on Regge theory to describe photoproduction of light vector mesons. We fit the SLAC data and make predictions for the energy and momentum transfer dependence of the spin-density matrix elements in photoproduction of $\omega$, $\rho^0$ and $\phi$ mesons at $E_\gamma \sim 8.5$ GeV, which are soon to be measured at Jefferson Lab.
[ { "created": "Mon, 26 Feb 2018 15:32:57 GMT", "version": "v1" } ]
2018-05-16
[ [ "JPAC Collaboration", "", "" ], [ "Mathieu", "V.", "" ], [ "Nys", "J.", "" ], [ "Fernández-Ramírez", "C.", "" ], [ "Jackura", "A.", "" ], [ "Pilloni", "A.", "" ], [ "Sherrill", "N.", "" ], [ "Szczepaniak", "A.", "" ], [ "Fox", "G.", "" ] ]
We propose a model based on Regge theory to describe photoproduction of light vector mesons. We fit the SLAC data and make predictions for the energy and momentum transfer dependence of the spin-density matrix elements in photoproduction of $\omega$, $\rho^0$ and $\phi$ mesons at $E_\gamma \sim 8.5$ GeV, which are soon to be measured at Jefferson Lab.
2304.06063
Spencer Chang
Layne Bradshaw, Spencer Chang
Primary Observables for Top Quark Collider Signals
37 pages, final published version in PRD
Phys.Rev.D 108 (2023) 1, 015019
10.1103/PhysRevD.108.015019
null
hep-ph hep-ex
http://creativecommons.org/licenses/by-nc-sa/4.0/
At the HL-LHC and future high energy colliders, a sample of a billion top quarks will be produced, allowing precision searches for new physics in top quark decay and production. To aid in this endeavor, we characterize the independent three and four point on-shell amplitudes involving top quarks, under the assumption of $SU(3)_c\times U(1)_{em}$ invariance. The four point amplitudes factorize into primary and descendent amplitudes, where descendants are primaries multiplied by Mandelstam variables. By enumerating the allowed amplitudes, we can check for amplitude redundancies to find the number of independent terms and convert those into a Lagrangian which parameterizes these amplitudes. These results are then cross checked by utilizing the Hilbert series to count the number of independent Lagrangian operators. Interestingly, we find situations where the Hilbert series has cancellations which, if na\"{i}vely interpreted, would lead to the incorrect conclusion that that there are no primary operators at a given mass dimension. We characterize the four fermion ($ffff$) and two fermion, two gauge boson ($ffVV$) operators respectively up to dimension 12 and 13. Finally, by combining unitarity bounds on the coupling strengths and simple estimates of the branching ratio sensitivities, we highlight interesting amplitudes for top quark decay that should be studied more closely at the HL-LHC. Of those highlighted, there are both new charge current and flavor changing neutral current decays that occur at dimension 8 and 10 in SMEFT.
[ { "created": "Wed, 12 Apr 2023 18:00:00 GMT", "version": "v1" }, { "created": "Thu, 7 Sep 2023 23:15:13 GMT", "version": "v2" } ]
2023-09-11
[ [ "Bradshaw", "Layne", "" ], [ "Chang", "Spencer", "" ] ]
At the HL-LHC and future high energy colliders, a sample of a billion top quarks will be produced, allowing precision searches for new physics in top quark decay and production. To aid in this endeavor, we characterize the independent three and four point on-shell amplitudes involving top quarks, under the assumption of $SU(3)_c\times U(1)_{em}$ invariance. The four point amplitudes factorize into primary and descendent amplitudes, where descendants are primaries multiplied by Mandelstam variables. By enumerating the allowed amplitudes, we can check for amplitude redundancies to find the number of independent terms and convert those into a Lagrangian which parameterizes these amplitudes. These results are then cross checked by utilizing the Hilbert series to count the number of independent Lagrangian operators. Interestingly, we find situations where the Hilbert series has cancellations which, if na\"{i}vely interpreted, would lead to the incorrect conclusion that that there are no primary operators at a given mass dimension. We characterize the four fermion ($ffff$) and two fermion, two gauge boson ($ffVV$) operators respectively up to dimension 12 and 13. Finally, by combining unitarity bounds on the coupling strengths and simple estimates of the branching ratio sensitivities, we highlight interesting amplitudes for top quark decay that should be studied more closely at the HL-LHC. Of those highlighted, there are both new charge current and flavor changing neutral current decays that occur at dimension 8 and 10 in SMEFT.
hep-ph/9403267
null
Daniel Boyanovsky, Richard Holman, Da-Shin Lee, Jo\~ao P. Silva
A Note on Thermal Activation
21 pages in LaTeX (1 figure, not included), CMU-HEP94-08
Nucl.Phys. B441 (1995) 595-608
10.1140/epjc/s2004-01858-5
null
hep-ph
null
Thermal activation is mediated by field configurations that correspond to saddle points of the energy functional. The rate of probability flow along the unstable functional directions, i.e the activation rate, is usually obtained from the imaginary part of a suitable analytic continuation of the equilibrium free energy. In this note we provide a real-time, non-equilibrium interpretation of this imaginary part which is analogous to the real-time interpretation of the imaginary part of the one-loop effective potential in theories with symmetry breaking. We argue that in situations in which the system is strongly out of equilibrium the rate will be time dependent and illustrate this with an example.
[ { "created": "Thu, 10 Mar 1994 22:55:47 GMT", "version": "v1" } ]
2017-01-18
[ [ "Boyanovsky", "Daniel", "" ], [ "Holman", "Richard", "" ], [ "Lee", "Da-Shin", "" ], [ "Silva", "João P.", "" ] ]
Thermal activation is mediated by field configurations that correspond to saddle points of the energy functional. The rate of probability flow along the unstable functional directions, i.e the activation rate, is usually obtained from the imaginary part of a suitable analytic continuation of the equilibrium free energy. In this note we provide a real-time, non-equilibrium interpretation of this imaginary part which is analogous to the real-time interpretation of the imaginary part of the one-loop effective potential in theories with symmetry breaking. We argue that in situations in which the system is strongly out of equilibrium the rate will be time dependent and illustrate this with an example.
hep-ph/0510280
Kaushik Bhattacharya
Kaushik Bhattacharya
Gauge invariance of elementary particle processes taking place in presence of a background magnetic field
Latex file, 16 pages
Int.J.Mod.Phys. A21 (2006) 3151-3170
10.1142/S0217751X06031594
null
hep-ph
null
Elementary particle scatterings and decays in presence of a background magnetic field are very common in physics, specially after the observation that the core of the neutron stars can sustain a magnetic field of the order of $10^{13} {\rm G}$. The important point about these calculations is that they are done in a background of a gauge field and as a result the calculations are prone to gauge arbitrariness. In this work we will investigate how this gauge arbitrariness is eradicated in processes where the initial and final particles taking part in the interactions are electrically neutral. Some comments on those processes where the initial or final state consists of electrically charged particles is presented at the end of the article.
[ { "created": "Fri, 21 Oct 2005 09:06:55 GMT", "version": "v1" } ]
2009-11-11
[ [ "Bhattacharya", "Kaushik", "" ] ]
Elementary particle scatterings and decays in presence of a background magnetic field are very common in physics, specially after the observation that the core of the neutron stars can sustain a magnetic field of the order of $10^{13} {\rm G}$. The important point about these calculations is that they are done in a background of a gauge field and as a result the calculations are prone to gauge arbitrariness. In this work we will investigate how this gauge arbitrariness is eradicated in processes where the initial and final particles taking part in the interactions are electrically neutral. Some comments on those processes where the initial or final state consists of electrically charged particles is presented at the end of the article.
1704.08262
Piotr Pietrulewicz
Daniele Bertolini, Daniel Kolodrubetz, Duff Neill, Piotr Pietrulewicz, Iain W. Stewart, Frank J. Tackmann, Wouter J. Waalewijn
Soft Functions for Generic Jet Algorithms and Observables at Hadron Colliders
33 pages + appendices, 17 figures, v2: journal version, v3: fixed typo in eq.(4.37)
null
10.1007/JHEP07(2017)099
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We introduce a method to compute one-loop soft functions for exclusive $N$-jet processes at hadron colliders, allowing for different definitions of the algorithm that determines the jet regions and of the measurements in those regions. In particular, we generalize the $N$-jettiness hemisphere decomposition of [Jouttenus 2011] in a manner that separates the dependence on the jet boundary from the observables measured inside the jet and beam regions. Results are given for several factorizable jet definitions, including anti-$k_T$, XCone, and other geometric partitionings. We calculate explicitly the soft functions for angularity measurements, including jet mass and jet broadening, in $pp \to L + 1$ jet and explore the differences for various jet vetoes and algorithms. This includes a consistent treatment of rapidity divergences when applicable. We also compute analytic results for these soft functions in an expansion for a small jet radius $R$. We find that the small-$R$ results, including corrections up to $\mathcal{O}(R^2)$, accurately capture the full behavior over a large range of $R$.
[ { "created": "Wed, 26 Apr 2017 18:00:10 GMT", "version": "v1" }, { "created": "Wed, 26 Jul 2017 08:27:58 GMT", "version": "v2" }, { "created": "Sat, 7 Oct 2017 08:53:11 GMT", "version": "v3" } ]
2017-10-10
[ [ "Bertolini", "Daniele", "" ], [ "Kolodrubetz", "Daniel", "" ], [ "Neill", "Duff", "" ], [ "Pietrulewicz", "Piotr", "" ], [ "Stewart", "Iain W.", "" ], [ "Tackmann", "Frank J.", "" ], [ "Waalewijn", "Wouter J.", "" ] ]
We introduce a method to compute one-loop soft functions for exclusive $N$-jet processes at hadron colliders, allowing for different definitions of the algorithm that determines the jet regions and of the measurements in those regions. In particular, we generalize the $N$-jettiness hemisphere decomposition of [Jouttenus 2011] in a manner that separates the dependence on the jet boundary from the observables measured inside the jet and beam regions. Results are given for several factorizable jet definitions, including anti-$k_T$, XCone, and other geometric partitionings. We calculate explicitly the soft functions for angularity measurements, including jet mass and jet broadening, in $pp \to L + 1$ jet and explore the differences for various jet vetoes and algorithms. This includes a consistent treatment of rapidity divergences when applicable. We also compute analytic results for these soft functions in an expansion for a small jet radius $R$. We find that the small-$R$ results, including corrections up to $\mathcal{O}(R^2)$, accurately capture the full behavior over a large range of $R$.
1407.2191
Sylvain Mogliacci
Sylvain Mogliacci
Probing the finite density equation of state of QCD via resummed perturbation theory
83 pages, 15 figures, PhD thesis
null
null
null
hep-ph hep-lat hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this Ph.D. thesis, the primary goal is to present a recent investigation of the finite density thermodynamics of hot and dense quark-gluon plasma. As we are interested in a temperature regime, in which naive perturbation theory is known to lose its predictive power, we clearly need to use a refined approach. To this end, we adopt a resummed perturbation theory point of view and employ two different frameworks. We first use hard-thermal-loop perturbation theory (HLTpt) at leading order to obtain the pressure for nonvanishing quark chemical potentials, and next, inspired by dimensional reduction, resum the known four-loop weak coupling expansion for the quantity. We present and analyze our findings for various cumulants of conserved charges. This provides us with information, through correlations and fluctuations, on the degrees of freedom effectively present in the quark-gluon plasma right above the deconfinement transition. Moreover, we compare our results with state-of-the-art lattice Monte Carlo simulations as well as with a recent three-loop mass truncated HTLpt calculation. We obtain very good agreement between the two different perturbative schemes, as well as between them and lattice data, down to surprisingly low temperatures right above the phase transition. We also quantitatively test the convergence of an approximation, which is used in higher order loop calculations in HTLpt. This method based on expansions in mass parameters, is unavoidable beyond leading order, thus motivating our investigation. We find the ensuing convergence to be very fast, validating its use in higher order computations.
[ { "created": "Tue, 8 Jul 2014 18:13:14 GMT", "version": "v1" } ]
2014-07-09
[ [ "Mogliacci", "Sylvain", "" ] ]
In this Ph.D. thesis, the primary goal is to present a recent investigation of the finite density thermodynamics of hot and dense quark-gluon plasma. As we are interested in a temperature regime, in which naive perturbation theory is known to lose its predictive power, we clearly need to use a refined approach. To this end, we adopt a resummed perturbation theory point of view and employ two different frameworks. We first use hard-thermal-loop perturbation theory (HLTpt) at leading order to obtain the pressure for nonvanishing quark chemical potentials, and next, inspired by dimensional reduction, resum the known four-loop weak coupling expansion for the quantity. We present and analyze our findings for various cumulants of conserved charges. This provides us with information, through correlations and fluctuations, on the degrees of freedom effectively present in the quark-gluon plasma right above the deconfinement transition. Moreover, we compare our results with state-of-the-art lattice Monte Carlo simulations as well as with a recent three-loop mass truncated HTLpt calculation. We obtain very good agreement between the two different perturbative schemes, as well as between them and lattice data, down to surprisingly low temperatures right above the phase transition. We also quantitatively test the convergence of an approximation, which is used in higher order loop calculations in HTLpt. This method based on expansions in mass parameters, is unavoidable beyond leading order, thus motivating our investigation. We find the ensuing convergence to be very fast, validating its use in higher order computations.
0711.2908
Shin'ichiro Ando
Shin'ichiro Ando (Caltech), John F. Beacom (Ohio State), Stefano Profumo (UCSC/Caltech), David Rainwater (Rochester)
Probing new physics with long-lived charged particles produced by atmospheric and astrophysical neutrinos
27 pages, 6 figures; accepted for publication in JCAP
JCAP 0804:029,2008
10.1088/1475-7516/2008/04/029
null
hep-ph astro-ph
null
As suggested by some extensions of the Standard Model of particle physics, dark matter may be a super-weakly interacting lightest stable particle, while the next-to-lightest particle (NLP) is charged and meta-stable. One could test such a possibility with neutrino telescopes, by detecting the charged NLPs produced in high-energy neutrino collisions with Earth matter. We study the production of charged NLPs by both atmospheric and astrophysical neutrinos; only the latter, which is largely uncertain and has not been detected yet, was the focus of previous studies. We compute the resulting fluxes of the charged NLPs, compare those of different origins, and analyze the dependence on the underlying particle physics setup. We point out that even if the astrophysical neutrino flux is very small, atmospheric neutrinos, especially those from the prompt decay of charmed mesons, may provide a detectable flux of NLP pairs at neutrino telescopes such as IceCube. We also comment on the flux of charged NLPs expected from proton-nucleon collisions, and show that, for theoretically motivated and phenomenologically viable models, it is typically sub-dominant and below detectable rates.
[ { "created": "Mon, 19 Nov 2007 20:04:33 GMT", "version": "v1" }, { "created": "Wed, 26 Mar 2008 19:21:25 GMT", "version": "v2" } ]
2009-01-06
[ [ "Ando", "Shin'ichiro", "", "Caltech" ], [ "Beacom", "John F.", "", "Ohio State" ], [ "Profumo", "Stefano", "", "UCSC/Caltech" ], [ "Rainwater", "David", "", "Rochester" ] ]
As suggested by some extensions of the Standard Model of particle physics, dark matter may be a super-weakly interacting lightest stable particle, while the next-to-lightest particle (NLP) is charged and meta-stable. One could test such a possibility with neutrino telescopes, by detecting the charged NLPs produced in high-energy neutrino collisions with Earth matter. We study the production of charged NLPs by both atmospheric and astrophysical neutrinos; only the latter, which is largely uncertain and has not been detected yet, was the focus of previous studies. We compute the resulting fluxes of the charged NLPs, compare those of different origins, and analyze the dependence on the underlying particle physics setup. We point out that even if the astrophysical neutrino flux is very small, atmospheric neutrinos, especially those from the prompt decay of charmed mesons, may provide a detectable flux of NLP pairs at neutrino telescopes such as IceCube. We also comment on the flux of charged NLPs expected from proton-nucleon collisions, and show that, for theoretically motivated and phenomenologically viable models, it is typically sub-dominant and below detectable rates.
hep-ph/9610336
Dirk Jungnickel
D.-U. Jungnickel and C. Wetterich (ITP Heidelberg)
Nonperturbative Flow Equations and Low--Energy QCD
34 pages, 4 figures ; Based on invited talks by the authors at the `Workshop on Quantum Chromodynamics: Confinement, Collisions, and Chaos', Paris, France, June 1996, and `QCD 96', Yaroslavl, Russia, May 1996
null
null
HD-THEP-96-40
hep-ph
null
We review the formalism of the effective average action in quantum field theory which corresponds to a coarse grained free energy in statistical mechanics. The associated exact renormalization group equation and possible nonperturbative approximations for its solution are discussed. This is applied to QCD where one observes the consecutive emergence of mesonic bound states and spontaneous chiral symmetry breaking as the coarse graining scale is lowered. We finally present a study of the phenomenological importance of non--renormalizable terms in the effective linear meson model.
[ { "created": "Fri, 11 Oct 1996 17:48:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jungnickel", "D. -U.", "", "ITP Heidelberg" ], [ "Wetterich", "C.", "", "ITP Heidelberg" ] ]
We review the formalism of the effective average action in quantum field theory which corresponds to a coarse grained free energy in statistical mechanics. The associated exact renormalization group equation and possible nonperturbative approximations for its solution are discussed. This is applied to QCD where one observes the consecutive emergence of mesonic bound states and spontaneous chiral symmetry breaking as the coarse graining scale is lowered. We finally present a study of the phenomenological importance of non--renormalizable terms in the effective linear meson model.
hep-ph/0402147
Karol Kampf
Jiri Horejsi, Karol Kampf
Contribution of dimension-six bosonic operators to Higgs decay into two photons at one-loop level
null
Mod.Phys.Lett. A19 (2004) 1681-1694
10.1142/S0217732304014045
null
hep-ph
null
The decay of the Higgs boson into two photons is examined in a model-independent way within the effective Lagrangian approach. Contribution of one-loop diagrams including SU(2) x U(1) invariant dimension-six bosonic operators is evaluated explicitly. The calculation is intended to fill a gap that exists in the current literature of the subject.
[ { "created": "Fri, 13 Feb 2004 18:36:15 GMT", "version": "v1" }, { "created": "Thu, 1 Jul 2004 13:23:59 GMT", "version": "v2" } ]
2009-11-10
[ [ "Horejsi", "Jiri", "" ], [ "Kampf", "Karol", "" ] ]
The decay of the Higgs boson into two photons is examined in a model-independent way within the effective Lagrangian approach. Contribution of one-loop diagrams including SU(2) x U(1) invariant dimension-six bosonic operators is evaluated explicitly. The calculation is intended to fill a gap that exists in the current literature of the subject.
1810.03097
Jale Y. S\'ung\'u
J.Y. S\"ung\"u and A.C. Jumasahatov
Probing Axial-Vector Charmonia $\chi_{c1}(1P)$ and $\chi_{c1}(2P)$
12 pages, 8 figures, article
null
10.1088/1361-6471/ab0115
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the ground-state heavy quarkonium $\chi_{c1}(1P)$ and its first excited state $\chi_{c1}(2P)$ with quantum numbers $J^{PC}=1^{++}$. The masses and decay constants of these charmonium states are computed using two-point QCD sum rule method by including quark, gluon and mixed condensates up to dimension-8. We compare our numerical results with the available experimental data as well as existing theoretical predictions in the literature.
[ { "created": "Sun, 7 Oct 2018 07:55:17 GMT", "version": "v1" }, { "created": "Tue, 9 Oct 2018 15:47:50 GMT", "version": "v2" } ]
2019-03-27
[ [ "Süngü", "J. Y.", "" ], [ "Jumasahatov", "A. C.", "" ] ]
We investigate the ground-state heavy quarkonium $\chi_{c1}(1P)$ and its first excited state $\chi_{c1}(2P)$ with quantum numbers $J^{PC}=1^{++}$. The masses and decay constants of these charmonium states are computed using two-point QCD sum rule method by including quark, gluon and mixed condensates up to dimension-8. We compare our numerical results with the available experimental data as well as existing theoretical predictions in the literature.
hep-ph/0610218
Patrick Aurenche
Patrick Aurenche (LAPTH)
Photon and dilepton production in heavy ion collisions at LHC
7 pages
null
null
null
hep-ph
null
We review various production mechanisms of photons and small mass dileptons at large transverse momentum in heavy ion collisions at the LHC. Their relevance as a signal for quark-gluon plasma formation is discussed.
[ { "created": "Tue, 17 Oct 2006 18:24:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Aurenche", "Patrick", "", "LAPTH" ] ]
We review various production mechanisms of photons and small mass dileptons at large transverse momentum in heavy ion collisions at the LHC. Their relevance as a signal for quark-gluon plasma formation is discussed.
0908.2027
Stefan Groote
S. Groote, H. Liivat, I. Ots, T. Sepp
Probing scalar particle and unparticle couplings in e+ e- -> t tbar with transversely polarized beams
28 pages in LaTeX, including 7 encapsulated PostScript figures, published version
Eur.Phys.J.C66:271-281,2010
10.1140/epjc/s10052-010-1237-2
MZ-TH/09-29
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In searching for indications of new physics scalar particle and unparticle couplings in e^+ e^- \to t\bar t, we consider the role of transversely polarized initial beams at e^+ e^- colliders. By using a general relativistic spin density matrix formalism for describing the particles spin states, we find analytical expressions for the squared amplitude of the process with t or \bar t polarization measured, including the anomalous coupling contributions. Thanks to the transversely polarized initial beams these contributions are first order anomalous coupling corrections to the Standard Model (SM) contributions. We present and analyse the main features of the SM and anomalous coupling contributions. We show how differences between SM and anomalous coupling contributions provide means to search for anomalous coupling manifestations at future e^+ e^- linear colliders.
[ { "created": "Fri, 14 Aug 2009 09:40:14 GMT", "version": "v1" }, { "created": "Thu, 15 Apr 2010 10:56:39 GMT", "version": "v2" } ]
2010-05-25
[ [ "Groote", "S.", "" ], [ "Liivat", "H.", "" ], [ "Ots", "I.", "" ], [ "Sepp", "T.", "" ] ]
In searching for indications of new physics scalar particle and unparticle couplings in e^+ e^- \to t\bar t, we consider the role of transversely polarized initial beams at e^+ e^- colliders. By using a general relativistic spin density matrix formalism for describing the particles spin states, we find analytical expressions for the squared amplitude of the process with t or \bar t polarization measured, including the anomalous coupling contributions. Thanks to the transversely polarized initial beams these contributions are first order anomalous coupling corrections to the Standard Model (SM) contributions. We present and analyse the main features of the SM and anomalous coupling contributions. We show how differences between SM and anomalous coupling contributions provide means to search for anomalous coupling manifestations at future e^+ e^- linear colliders.
hep-ph/0607156
Jeppe R. Andersen
Jeppe R. Andersen
Multi-Jet Processes in the High Energy Limit of QCD
5 pages, 1 figure, prepared for the proceedings of the 14th International Workshop on Deep Inelastic Scattering (DIS06), Tsukuba, Japan, 20-24 April 2006
null
10.1142/9789812706706_0121
CAVENDISH-HEP-06-16
hep-ph
null
We discuss how the multi-Regge factorisation of QCD amplitudes can be used in the study of multi-jet processes at colliders. We describe how the next-to-leading logarithmic (NLL) BFKL evolution can be combined with energy and momentum conservation. By recalculating the quark contribution to the next-to-leading logarithmic corrections to the BFKL kernel we can study several properties of the NLL corrections. We demonstrate that in the standard analysis, the NLL corrections to a single gluon emission includes contributions from significantly more energetic quark--anti-quark configurations, something that could contribute to the sizable NLL corrections in the standard BFKL analysis.
[ { "created": "Thu, 13 Jul 2006 18:53:31 GMT", "version": "v1" } ]
2017-08-23
[ [ "Andersen", "Jeppe R.", "" ] ]
We discuss how the multi-Regge factorisation of QCD amplitudes can be used in the study of multi-jet processes at colliders. We describe how the next-to-leading logarithmic (NLL) BFKL evolution can be combined with energy and momentum conservation. By recalculating the quark contribution to the next-to-leading logarithmic corrections to the BFKL kernel we can study several properties of the NLL corrections. We demonstrate that in the standard analysis, the NLL corrections to a single gluon emission includes contributions from significantly more energetic quark--anti-quark configurations, something that could contribute to the sizable NLL corrections in the standard BFKL analysis.
2309.06156
Hiwa Ahmed
Hiwa A. Ahmed, Yidian Chen, Mei Huang
$D_{(s)}-$ mesons semileptonic form factors in the 4-flavor holographic QCD
arXiv admin note: text overlap with arXiv:2308.14975
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate semileptonic form factors of $D_{(s)}$ meson from a modified soft-wall 4-flavor holographic model. The model successfully reproduces the masses and decay constants of various mesons, including $\rho$, $K^*$, $D^*$, $D_s^*$, $a_1$, $K_1$, $f_1$, $D_1$,$D_{s1}$, $\pi$, $K$, $\eta$, $D$, and $D_s$. Moreover, we study the semileptonic decay processes $D^{+} \to (\pi, K, \eta) l^{+} \nu_{l}$ and $D_{s}^{+} \to ( K, \eta) l^{+} \nu_{l}$, associated with the vector meson exchange, as well as $D_{(s)}^{+} \to K^{} l^{+} \nu_{l}$, associated with the vector and axial vector meson exchange. The form factors $f_{+}(q^{2})$ for $D \to\pi$ and $D_{(s)}\to K$ decays agree excellently with experimental and lattice data, outperforming other theoretical approaches. The $f_{+}(q^{2})$ form factor for $D^{+} \to \eta $ is compatible with experimental data, while a slight discrepancy is observed for $D_{s}^{+} \to \eta $ at large $q^{2}$. Additionally, we predict the vector form factors $V(q^{2})$ and $A_{1}(q^{2})$ for $D \to K^{}$ and $D_{s} \to K^{}$ decays, respectively. The results agree well with other approaches and lattice data at maximum recoil ($q^{2}=0$).
[ { "created": "Tue, 12 Sep 2023 11:58:28 GMT", "version": "v1" } ]
2023-09-13
[ [ "Ahmed", "Hiwa A.", "" ], [ "Chen", "Yidian", "" ], [ "Huang", "Mei", "" ] ]
We investigate semileptonic form factors of $D_{(s)}$ meson from a modified soft-wall 4-flavor holographic model. The model successfully reproduces the masses and decay constants of various mesons, including $\rho$, $K^*$, $D^*$, $D_s^*$, $a_1$, $K_1$, $f_1$, $D_1$,$D_{s1}$, $\pi$, $K$, $\eta$, $D$, and $D_s$. Moreover, we study the semileptonic decay processes $D^{+} \to (\pi, K, \eta) l^{+} \nu_{l}$ and $D_{s}^{+} \to ( K, \eta) l^{+} \nu_{l}$, associated with the vector meson exchange, as well as $D_{(s)}^{+} \to K^{} l^{+} \nu_{l}$, associated with the vector and axial vector meson exchange. The form factors $f_{+}(q^{2})$ for $D \to\pi$ and $D_{(s)}\to K$ decays agree excellently with experimental and lattice data, outperforming other theoretical approaches. The $f_{+}(q^{2})$ form factor for $D^{+} \to \eta $ is compatible with experimental data, while a slight discrepancy is observed for $D_{s}^{+} \to \eta $ at large $q^{2}$. Additionally, we predict the vector form factors $V(q^{2})$ and $A_{1}(q^{2})$ for $D \to K^{}$ and $D_{s} \to K^{}$ decays, respectively. The results agree well with other approaches and lattice data at maximum recoil ($q^{2}=0$).
hep-ph/9806303
Antonio Pich
A. Pich
Effective Field Theory
106 pages, 20 figures. Lectures at the 1997 Les Houches Summer School "Probing the Standard Model of Particle Interactions"
null
null
FTUV/98-46, IFIC/98-47
hep-ph
null
These lectures provide an introduction to the basic ideas and methods of Effective Field Theory, and a description of a few interesting phenomenological applications in particle physics. The main conceptual foundations are discussed in sections 2 and 3, which cover the momentum expansion and the most important issues associated with the renormalization process. Section 4 presents an overview of Chiral Perturbation Theory, the low-energy realization of Quantum Chromodynamics in the light quark sector. The Chiral Perturbation Theory framework is applied to weak transitions in section 5, where the physics of non-leptonic kaon decays is analyzed. The so-called Heavy Quark Effective Theory is briefly discussed in section 6. The electroweak chiral Effective Field Theory is described in section 7, which contains a brief overview of the effective Lagrangian associated with the spontaneous electroweak symmetry breaking. Some summarizing comments are finally given in section 8.
[ { "created": "Mon, 8 Jun 1998 12:53:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pich", "A.", "" ] ]
These lectures provide an introduction to the basic ideas and methods of Effective Field Theory, and a description of a few interesting phenomenological applications in particle physics. The main conceptual foundations are discussed in sections 2 and 3, which cover the momentum expansion and the most important issues associated with the renormalization process. Section 4 presents an overview of Chiral Perturbation Theory, the low-energy realization of Quantum Chromodynamics in the light quark sector. The Chiral Perturbation Theory framework is applied to weak transitions in section 5, where the physics of non-leptonic kaon decays is analyzed. The so-called Heavy Quark Effective Theory is briefly discussed in section 6. The electroweak chiral Effective Field Theory is described in section 7, which contains a brief overview of the effective Lagrangian associated with the spontaneous electroweak symmetry breaking. Some summarizing comments are finally given in section 8.
2109.01675
Hector Gisbert Mullor
Rigo Bause, Hector Gisbert, Marcel Golz, Gudrun Hiller
Interplay of dineutrino modes with semileptonic rare $\boldsymbol{B}$-decays
40 pages, 4 figures, 10 tables. v2: minor clarifications, fits the accepted version of JHEP
JHEP 12 (2021) 061
10.1007/JHEP12(2021)061
DO-TH 21/17
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a systematic global analysis of dineutrino modes $b \to q \,\nu \bar \nu$, $q=d,s$, and charged dilepton $b \to q \,\ell^+ \ell^-$ transitions. We derive improved or even entirely new limits on dineutrino branching ratios including decays $B^0 \to (K^0 , X_s)\, \nu \bar \nu$, $B_s \to \phi \,\nu \bar \nu$ and $B^0 \to (\pi^0, \rho^0)\, \nu \bar \nu$ from dineutrino modes which presently are best constrained: $B^+ \to (K^+,\pi^+, \rho^+) \,\nu \bar \nu$ and $B^0 \to K^{*0} \,\nu \bar \nu$. Using SMEFT we obtain new flavor constraints from the dineutrino modes, which are stronger than the corresponding ones from charged dilepton rare $b$-decay or Drell-Yan data, for $e \tau$ and $\tau \tau$ final states, as well as for $\mu \tau$ ones in $b \to s$ processes. The method also allows to put novel constraints on semileptonic four-fermion operators with top quarks. Implications for ditau modes $b \to s \, \tau^+ \tau^-$ and $b \to d \, \tau^+ \tau^-$ are worked out. Furthermore, the interplay between dineutrinos and charged dileptons allows for concrete, novel tests of lepton universality in rare $B$-decays. Performing a global fit to $b \to s \,\mu^+ \mu^-, \,s \gamma$ transitions we find that lepton universality predicts the ratio of the $B^0 \to K^{*0} \,\nu \bar \nu$ to $B^0 \to K^0 \,\nu \bar \nu$ ($B^+ \to K^+ \,\nu \bar \nu$) branching fractions to be within 1.7 to 2.6 (1.6 to 2.4) at $1\,\sigma$, a region that includes the standard model, and that can be narrowed with improved charged dilepton data. There is sizable room outside this region where universality is broken and that can be probed with the Belle II experiment. Using results of a fit to $B^0 \to \mu^+ \mu^-$, $B^0_s\to \bar{K}^{\ast 0}\,\mu^+\mu^-$ and $ B^+ \to \pi^+\, \mu^+ \mu^-$ data we obtain an analogous relation for $|\Delta b|=|\Delta d|=1$ transitions.
[ { "created": "Fri, 3 Sep 2021 18:00:02 GMT", "version": "v1" }, { "created": "Wed, 8 Dec 2021 14:05:40 GMT", "version": "v2" } ]
2021-12-20
[ [ "Bause", "Rigo", "" ], [ "Gisbert", "Hector", "" ], [ "Golz", "Marcel", "" ], [ "Hiller", "Gudrun", "" ] ]
We present a systematic global analysis of dineutrino modes $b \to q \,\nu \bar \nu$, $q=d,s$, and charged dilepton $b \to q \,\ell^+ \ell^-$ transitions. We derive improved or even entirely new limits on dineutrino branching ratios including decays $B^0 \to (K^0 , X_s)\, \nu \bar \nu$, $B_s \to \phi \,\nu \bar \nu$ and $B^0 \to (\pi^0, \rho^0)\, \nu \bar \nu$ from dineutrino modes which presently are best constrained: $B^+ \to (K^+,\pi^+, \rho^+) \,\nu \bar \nu$ and $B^0 \to K^{*0} \,\nu \bar \nu$. Using SMEFT we obtain new flavor constraints from the dineutrino modes, which are stronger than the corresponding ones from charged dilepton rare $b$-decay or Drell-Yan data, for $e \tau$ and $\tau \tau$ final states, as well as for $\mu \tau$ ones in $b \to s$ processes. The method also allows to put novel constraints on semileptonic four-fermion operators with top quarks. Implications for ditau modes $b \to s \, \tau^+ \tau^-$ and $b \to d \, \tau^+ \tau^-$ are worked out. Furthermore, the interplay between dineutrinos and charged dileptons allows for concrete, novel tests of lepton universality in rare $B$-decays. Performing a global fit to $b \to s \,\mu^+ \mu^-, \,s \gamma$ transitions we find that lepton universality predicts the ratio of the $B^0 \to K^{*0} \,\nu \bar \nu$ to $B^0 \to K^0 \,\nu \bar \nu$ ($B^+ \to K^+ \,\nu \bar \nu$) branching fractions to be within 1.7 to 2.6 (1.6 to 2.4) at $1\,\sigma$, a region that includes the standard model, and that can be narrowed with improved charged dilepton data. There is sizable room outside this region where universality is broken and that can be probed with the Belle II experiment. Using results of a fit to $B^0 \to \mu^+ \mu^-$, $B^0_s\to \bar{K}^{\ast 0}\,\mu^+\mu^-$ and $ B^+ \to \pi^+\, \mu^+ \mu^-$ data we obtain an analogous relation for $|\Delta b|=|\Delta d|=1$ transitions.
hep-ph/0001192
Pavel Baikov
P.A. Baikov and V.A. Smirnov (Institute of Nuclear Physics of Moscow State University)
Equivalence of Recurrence Relations for Feynman Integrals with the Same Total Number of External and Loop Momenta
8 pp., LaTeX with axodraw.sty
Phys.Lett. B477 (2000) 367-372
10.1016/S0370-2693(00)00222-7
NPI MSU 2000--4/608
hep-ph hep-th
null
We show that the problem of solving recurrence relations for L-loop (R+1)-point Feynman integrals within the method of integration by parts is equivalent to the corresponding problem for (L+R)-loop vacuum or (L+R-1)-loop propagator-type integrals. Using this property we solve recurrence relations for two-loop massless vertex diagrams, with arbitrary numerators and integer powers of propagators in the case when two legs are on the light cone, by reducing the problem to the well-known solution of the corresponding recurrence relations for massless three-loop propagator diagrams with specific boundary conditions.
[ { "created": "Wed, 19 Jan 2000 11:50:25 GMT", "version": "v1" } ]
2009-10-31
[ [ "Baikov", "P. A.", "", "Institute of Nuclear Physics of Moscow\n State University" ], [ "Smirnov", "V. A.", "", "Institute of Nuclear Physics of Moscow\n State University" ] ]
We show that the problem of solving recurrence relations for L-loop (R+1)-point Feynman integrals within the method of integration by parts is equivalent to the corresponding problem for (L+R)-loop vacuum or (L+R-1)-loop propagator-type integrals. Using this property we solve recurrence relations for two-loop massless vertex diagrams, with arbitrary numerators and integer powers of propagators in the case when two legs are on the light cone, by reducing the problem to the well-known solution of the corresponding recurrence relations for massless three-loop propagator diagrams with specific boundary conditions.
hep-ph/0302172
Ben Gripaios
B. M. Gripaios, J. G. Milhano
Improved Variational Analysis of Deconfinement in SU(N) Gauge Theory
8 pages
Phys.Lett. B564 (2003) 104-110
10.1016/S0370-2693(03)00558-6
OUTP-03 07P
hep-ph
null
A variational analysis of the pure SU(N) gauge theory in 3+1 dimensions at finite temperature is performed, extending the work of Kogan, Kovner and Milhano in hep-ph/0208053 . A de-confining phase transition is found at a temperature of 470 MeV, somewhat higher than lattice estimates. This value is however rather sensitive, for reasons which are discussed. A more robust quantity is the ratio of the transition temperature to the lightest glueball mass in the model. This is 0.18, in agreement with the lattice estimate for SU(3) to two significant figures. Ways of further improving the calculation are discussed.
[ { "created": "Wed, 19 Feb 2003 15:34:21 GMT", "version": "v1" } ]
2009-11-10
[ [ "Gripaios", "B. M.", "" ], [ "Milhano", "J. G.", "" ] ]
A variational analysis of the pure SU(N) gauge theory in 3+1 dimensions at finite temperature is performed, extending the work of Kogan, Kovner and Milhano in hep-ph/0208053 . A de-confining phase transition is found at a temperature of 470 MeV, somewhat higher than lattice estimates. This value is however rather sensitive, for reasons which are discussed. A more robust quantity is the ratio of the transition temperature to the lightest glueball mass in the model. This is 0.18, in agreement with the lattice estimate for SU(3) to two significant figures. Ways of further improving the calculation are discussed.
hep-ph/9705455
null
J.J.M. Verbaarschot
Spectral Fluctuations of the QCD Dirac Operator
7 pages, 2 figures, Latex, Talk given at the Workshop on New Nonperturbative Methods and Quantization on the Light Cone, Les Houches, France, Feb 24-Mar 7, 1997
null
null
null
hep-ph
null
Recently, QCD Dirac spectra have been obtained for reasonably large lattices. We argue that correlations of these spectra are universal and can be obtained from a random matrix model with the global symmetries of QCD. Analytical arguments are presented to support this claim. Detailed comparisons with lattice results are made. We analyze spectral correlations in the bulk of the spectrum and find that long range fluctuations are strongly suppressed in complete agreement with random matrix theory. We study the valence quark mass dependence of the lattice QCD Dirac operator showing that the average spectral density near zero virtuality is given by chiral random matrix theory. This agrees with recent lattice calculations of the microscopic spectral density. of this lecture, we introduce a schematic random matrix model for the chiral phase transition at nonzero chemical potential. We consider both real, complex and quaternion real matrix elements. We find a remarkable triality for the distribution of of the eigenvalues in the complex plane. In particular, this elucidates the nature of the quenched approximation in each case.
[ { "created": "Wed, 28 May 1997 21:07:20 GMT", "version": "v1" } ]
2009-09-25
[ [ "Verbaarschot", "J. J. M.", "" ] ]
Recently, QCD Dirac spectra have been obtained for reasonably large lattices. We argue that correlations of these spectra are universal and can be obtained from a random matrix model with the global symmetries of QCD. Analytical arguments are presented to support this claim. Detailed comparisons with lattice results are made. We analyze spectral correlations in the bulk of the spectrum and find that long range fluctuations are strongly suppressed in complete agreement with random matrix theory. We study the valence quark mass dependence of the lattice QCD Dirac operator showing that the average spectral density near zero virtuality is given by chiral random matrix theory. This agrees with recent lattice calculations of the microscopic spectral density. of this lecture, we introduce a schematic random matrix model for the chiral phase transition at nonzero chemical potential. We consider both real, complex and quaternion real matrix elements. We find a remarkable triality for the distribution of of the eigenvalues in the complex plane. In particular, this elucidates the nature of the quenched approximation in each case.
1003.4664
Eulogio Oset
Bao-Xi Sun, E.J. Garzon and E. Oset
Radiative decay into gamma-baryon of dynamically generated resonances from the vector-baryon interaction
20 pages, 8 figures
Phys.Rev.D82:034028,2010
10.1103/PhysRevD.82.034028
FTUV-10-0324, IFIC-10-0324
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the radiative decay into $\gamma$ and a baryon of the SU(3) octet and decuplet of nine and ten resonances that are dynamically generated from the interaction of vector mesons with baryons of the octet and the decuplet respectively. We obtain quite different partial decay widths for the various resonances, and for different charge states of the same resonance, suggesting that the experimental investigation of these radiative decays should bring much information on the nature of these resonances. For the case of baryons of the octet we determine the helicity amplitudes and compare them with experimental data when available.
[ { "created": "Wed, 24 Mar 2010 15:08:13 GMT", "version": "v1" } ]
2014-11-20
[ [ "Sun", "Bao-Xi", "" ], [ "Garzon", "E. J.", "" ], [ "Oset", "E.", "" ] ]
We study the radiative decay into $\gamma$ and a baryon of the SU(3) octet and decuplet of nine and ten resonances that are dynamically generated from the interaction of vector mesons with baryons of the octet and the decuplet respectively. We obtain quite different partial decay widths for the various resonances, and for different charge states of the same resonance, suggesting that the experimental investigation of these radiative decays should bring much information on the nature of these resonances. For the case of baryons of the octet we determine the helicity amplitudes and compare them with experimental data when available.
hep-ph/9910307
Dayeeta Roy
D.Roy, T.Morii, H.Toki, A.Titov
Is there window for "supersoft" Pomeron in $J/\psi$ photoproduction at low energy?
9 pages including 2 figs
Prog.Theor.Phys. 103 (2000) 747-753
10.1143/PTP.103.747
null
hep-ph
null
The low energy $J/\psi$ photoproduction cross-section has been studied on the basis of the Pomeron model. To incorporate the discrepancy between experimental data and the predictionns by the conventional models, i.e. the sum of the soft Pomeron with intercept 1.08 and the hard Pomeron with intercept 1.418, a Regge trajectory associated with a scalar meson (f,a) exchange which we call "supersoft" Pomeron, is introduced additionally. To distinguish between the conventional model and this new additional Pomeron, observations related to other polarization observables in upcoming polarized experiments are discussed.
[ { "created": "Tue, 12 Oct 1999 07:32:20 GMT", "version": "v1" } ]
2009-10-31
[ [ "Roy", "D.", "" ], [ "Morii", "T.", "" ], [ "Toki", "H.", "" ], [ "Titov", "A.", "" ] ]
The low energy $J/\psi$ photoproduction cross-section has been studied on the basis of the Pomeron model. To incorporate the discrepancy between experimental data and the predictionns by the conventional models, i.e. the sum of the soft Pomeron with intercept 1.08 and the hard Pomeron with intercept 1.418, a Regge trajectory associated with a scalar meson (f,a) exchange which we call "supersoft" Pomeron, is introduced additionally. To distinguish between the conventional model and this new additional Pomeron, observations related to other polarization observables in upcoming polarized experiments are discussed.
0904.3037
Stanley J. Brodsky
Stanley J. Brodsky
Novel High Transverse Momentum Phenomena in Hadronic and Nuclear Collisions
Invited Talk, 4th International Workshop on High-PT Physics at the LHC 09
PoS High-pTphysics09:013,2009
null
SLAC-PUB 13571
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I discuss a number of novel phenomenological features of QCD in high transverse momentum reactions. The presence of direct higher-twist processes, where a proton is produced directly in the hard subprocess, can explain the "baryon anomaly" -- the large proton-to-pion ratio seen at RHIC in high centrality heavy ion collisions. Direct hadronic processes can also account for the deviation from leading-twist PQCD scaling at fixed x_T = 2p_T/\sqrt s. I suggest that the "ridge" -- the same-side long-range rapidity correlation observed at RHIC in high centrality heavy ion collisions is due to the imprint of semihard DGLAP gluon radiation from initial-state partons which have transverse momenta biased toward the trigger. Rescattering interactions from gluon-exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam-Tung relation in Drell-Yan reactions, nuclear shadowing --all leading-twist dynamics not incorporated in the light-front wavefunctions of the target computed in isolation. Antishadowing is shown to be quark flavor specific and thus different in charged and neutral deep inelastic lepton-nucleus scattering. I also discuss the consequences of color-octet intrinsic heavy quark distributions in the proton for heavy particle and Higgs production at high x_F. The AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories allows one to compute the analytic form of frame-independent light-front wavefunctions of mesons and baryons and to compute quark and gluon hadronization at the amplitude level.
[ { "created": "Sat, 18 Apr 2009 07:12:28 GMT", "version": "v1" } ]
2010-12-17
[ [ "Brodsky", "Stanley J.", "" ] ]
I discuss a number of novel phenomenological features of QCD in high transverse momentum reactions. The presence of direct higher-twist processes, where a proton is produced directly in the hard subprocess, can explain the "baryon anomaly" -- the large proton-to-pion ratio seen at RHIC in high centrality heavy ion collisions. Direct hadronic processes can also account for the deviation from leading-twist PQCD scaling at fixed x_T = 2p_T/\sqrt s. I suggest that the "ridge" -- the same-side long-range rapidity correlation observed at RHIC in high centrality heavy ion collisions is due to the imprint of semihard DGLAP gluon radiation from initial-state partons which have transverse momenta biased toward the trigger. Rescattering interactions from gluon-exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam-Tung relation in Drell-Yan reactions, nuclear shadowing --all leading-twist dynamics not incorporated in the light-front wavefunctions of the target computed in isolation. Antishadowing is shown to be quark flavor specific and thus different in charged and neutral deep inelastic lepton-nucleus scattering. I also discuss the consequences of color-octet intrinsic heavy quark distributions in the proton for heavy particle and Higgs production at high x_F. The AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories allows one to compute the analytic form of frame-independent light-front wavefunctions of mesons and baryons and to compute quark and gluon hadronization at the amplitude level.
2112.04518
Prabhat Solanki
Biplob Bhattacherjee, Tapasi Ghosh, Rhitaja Sengupta, Prabhat Solanki
Dedicated Triggers for Displaced Jets using Timing Information from Electromagnetic Calorimeter at HL-LHC
64 pages, 34 figures, 6 tables
null
10.1007/JHEP08(2022)254
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In this paper, we study the prospect of ECAL barrel timing to develop triggers dedicated to long-lived particles decaying to jets, at the level-1 of HL-LHC. We construct over 20 timing based variables, and identify three of them which have better performances and are robust against increasing PU. We estimate the QCD prompt jet background rates accurately using the "stitching" procedure for varying thresholds defining our triggers, and compute the signal efficiencies for different LLP scenarios for a permissible background rate. The trigger efficiencies can go up to $\mathcal{O}(80\%)$ for the most optimal trigger for pair-produced heavy LLPs having high decay lengths, which degrades with decreasing mass and decay length of the LLP. We also discuss the prospect of including the information of displaced L1 tracks to our triggers, which further improves the results, especially for LLPs characterised by lower decay lengths.
[ { "created": "Wed, 8 Dec 2021 19:00:12 GMT", "version": "v1" } ]
2022-09-14
[ [ "Bhattacherjee", "Biplob", "" ], [ "Ghosh", "Tapasi", "" ], [ "Sengupta", "Rhitaja", "" ], [ "Solanki", "Prabhat", "" ] ]
In this paper, we study the prospect of ECAL barrel timing to develop triggers dedicated to long-lived particles decaying to jets, at the level-1 of HL-LHC. We construct over 20 timing based variables, and identify three of them which have better performances and are robust against increasing PU. We estimate the QCD prompt jet background rates accurately using the "stitching" procedure for varying thresholds defining our triggers, and compute the signal efficiencies for different LLP scenarios for a permissible background rate. The trigger efficiencies can go up to $\mathcal{O}(80\%)$ for the most optimal trigger for pair-produced heavy LLPs having high decay lengths, which degrades with decreasing mass and decay length of the LLP. We also discuss the prospect of including the information of displaced L1 tracks to our triggers, which further improves the results, especially for LLPs characterised by lower decay lengths.
1408.5887
Jusak Tandean
Gaber Faisel, Shu-Yu Ho, Jusak Tandean
Exploring X-Ray Lines as Scotogenic Signals
12 pages, no figures, slightly revised, references added, main conclusions unchanged, journal version
Phys. Lett. B 738 (2014) 380-385
10.1016/j.physletb.2014.09.063
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider some implications of X-ray lines from certain astronomical objects as potential effects of dark matter decay in the context of the scotogenic model, where neutrinos acquire mass radiatively via one-loop interactions with dark matter. As an example, we focus on the 3.5 keV line recently detected in the X-ray spectra of galaxy clusters, assuming that it stands future scrutiny. We explore the scenario in which the line originates from the slow decay of fermionic dark matter in the model. After obtaining a number of benchmark points representing the parameter space consistent with the new data and various other constraints, we make predictions on several observables in leptonic processes. They include the effective Majorana mass in neutrinoless double-beta decay, the sum of neutrino masses, and the rate of flavor-changing decay mu -> e gamma, as well as the cross sections of e+e- collisions into final states containing nonstandard particles in the model. These are testable in ongoing or future experiments and thus offer means to probe the scotogenic scenario studied.
[ { "created": "Mon, 25 Aug 2014 19:56:55 GMT", "version": "v1" }, { "created": "Fri, 10 Oct 2014 19:25:46 GMT", "version": "v2" } ]
2014-10-28
[ [ "Faisel", "Gaber", "" ], [ "Ho", "Shu-Yu", "" ], [ "Tandean", "Jusak", "" ] ]
We consider some implications of X-ray lines from certain astronomical objects as potential effects of dark matter decay in the context of the scotogenic model, where neutrinos acquire mass radiatively via one-loop interactions with dark matter. As an example, we focus on the 3.5 keV line recently detected in the X-ray spectra of galaxy clusters, assuming that it stands future scrutiny. We explore the scenario in which the line originates from the slow decay of fermionic dark matter in the model. After obtaining a number of benchmark points representing the parameter space consistent with the new data and various other constraints, we make predictions on several observables in leptonic processes. They include the effective Majorana mass in neutrinoless double-beta decay, the sum of neutrino masses, and the rate of flavor-changing decay mu -> e gamma, as well as the cross sections of e+e- collisions into final states containing nonstandard particles in the model. These are testable in ongoing or future experiments and thus offer means to probe the scotogenic scenario studied.
2305.01002
Yongchao Zhang
P. S. Bhupal Dev, Jean-Fran\c{c}ois Fortin, Steven P. Harris, Kuver Sinha, Yongchao Zhang
First Constraints on the Photon Coupling of Axion-like Particles from Multimessenger Studies of the Neutron Star Merger GW170817
8+8 pages, 4+5 figures, some updates and minor changes, version to appear in PRL
null
null
INT-PUB-23-014
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
We use multimessenger observations of the neutron star merger event GW170817 to derive new constraints on axion-like particles (ALPs) coupling to photons. ALPs are produced via Primakoff and photon coalescence processes in the merger, escape the remnant and decay back into two photons, giving rise to a photon signal approximately along the line-of-sight to the merger. We analyze the spectral and temporal information of the ALP-induced photon signal, and use the Fermi-LAT observations of GW170817 to derive our new ALP constraints. We also show the improved prospects with future MeV gamma-ray missions, taking the spectral and temporal coverage of Fermi-LAT as an example.
[ { "created": "Mon, 1 May 2023 18:00:04 GMT", "version": "v1" }, { "created": "Tue, 27 Feb 2024 13:56:53 GMT", "version": "v2" } ]
2024-02-28
[ [ "Dev", "P. S. Bhupal", "" ], [ "Fortin", "Jean-François", "" ], [ "Harris", "Steven P.", "" ], [ "Sinha", "Kuver", "" ], [ "Zhang", "Yongchao", "" ] ]
We use multimessenger observations of the neutron star merger event GW170817 to derive new constraints on axion-like particles (ALPs) coupling to photons. ALPs are produced via Primakoff and photon coalescence processes in the merger, escape the remnant and decay back into two photons, giving rise to a photon signal approximately along the line-of-sight to the merger. We analyze the spectral and temporal information of the ALP-induced photon signal, and use the Fermi-LAT observations of GW170817 to derive our new ALP constraints. We also show the improved prospects with future MeV gamma-ray missions, taking the spectral and temporal coverage of Fermi-LAT as an example.
1407.7414
Thomas Wolkanowski
Jonas Schneitzer, Thomas Wolkanowski and Francesco Giacosa
The role of the next-to-leading order triangle-shaped diagram in two-body hadronic decays
18 pages, 6 figures, 1 table
Nucl.Phys.B888:287-299,2014
10.1016/j.nuclphysb.2014.10.003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The next-to-leading-order contribution to the amplitude of a two-body decay process is a triangle-shaped diagram in which the unstable state is exchanged by the emitted particles. In this work we calculate this diagram in the framework of a scalar quantum field theory and we estimate its role in hadronic physics, i.e., we apply our results to the well-known scalar-isoscalar resonances $f_{0}(500)$, $f_{0}(980)$, $f_{0}(1370)$, $f_{0}(1500)$, $f_{0}(1710)$ and the scalar-isovector resonance $a_{0}(1450)$. It turns out that, with the exception of the broad resonance $f_{0}(500)$, the next-to-leading-order contribution is small and can be neglected.
[ { "created": "Mon, 28 Jul 2014 13:39:32 GMT", "version": "v1" }, { "created": "Sat, 18 Oct 2014 21:10:15 GMT", "version": "v2" } ]
2014-10-30
[ [ "Schneitzer", "Jonas", "" ], [ "Wolkanowski", "Thomas", "" ], [ "Giacosa", "Francesco", "" ] ]
The next-to-leading-order contribution to the amplitude of a two-body decay process is a triangle-shaped diagram in which the unstable state is exchanged by the emitted particles. In this work we calculate this diagram in the framework of a scalar quantum field theory and we estimate its role in hadronic physics, i.e., we apply our results to the well-known scalar-isoscalar resonances $f_{0}(500)$, $f_{0}(980)$, $f_{0}(1370)$, $f_{0}(1500)$, $f_{0}(1710)$ and the scalar-isovector resonance $a_{0}(1450)$. It turns out that, with the exception of the broad resonance $f_{0}(500)$, the next-to-leading-order contribution is small and can be neglected.
hep-ph/9904268
J. Gunion
R. Casalbuoni, A. Deandrea, S. De Curtis, D. Dominici, R. Gatto and J.F. Gunion
Analysis of Narrow s-channel Resonances at Lepton Colliders
63 pages, 16 figures
JHEP 9908 (1999) 011
10.1088/1126-6708/1999/08/011
UCD-99-5
hep-ph
null
The procedures for studying a single narrow s-channel resonance or nearly degenerate resonances at a lepton collider, especially a muon collider, are discussed. In particular, we examine four methods for determining the parameters of a narrow s-channel resonance: scanning the resonance, measuring the convoluted cross section, measuring the Breit-Wigner area, and sitting on the resonance while varying the beam energy resolution. This latter procedure is new and appears to be potentially very powerful. Our focus is on computing the errors in resonance parameters resulting from uncertainty in the beam energy spread. Means for minimizing these errors are discussed. The discussion is applied to the examples of a light SM-Higgs, of the lightest pseudogoldstone boson of strong electroweak breaking, and of the two spin-1 resonances of the Degenerate BESS model (assuming that the beam energy spread is less than their mass splitting). We also examine the most effective procedures for nearly degenerate resonances, and apply these to the case of Degenerate BESS resonances with mass splitting of order the beam energy spread.
[ { "created": "Thu, 8 Apr 1999 18:18:38 GMT", "version": "v1" } ]
2009-10-31
[ [ "Casalbuoni", "R.", "" ], [ "Deandrea", "A.", "" ], [ "De Curtis", "S.", "" ], [ "Dominici", "D.", "" ], [ "Gatto", "R.", "" ], [ "Gunion", "J. F.", "" ] ]
The procedures for studying a single narrow s-channel resonance or nearly degenerate resonances at a lepton collider, especially a muon collider, are discussed. In particular, we examine four methods for determining the parameters of a narrow s-channel resonance: scanning the resonance, measuring the convoluted cross section, measuring the Breit-Wigner area, and sitting on the resonance while varying the beam energy resolution. This latter procedure is new and appears to be potentially very powerful. Our focus is on computing the errors in resonance parameters resulting from uncertainty in the beam energy spread. Means for minimizing these errors are discussed. The discussion is applied to the examples of a light SM-Higgs, of the lightest pseudogoldstone boson of strong electroweak breaking, and of the two spin-1 resonances of the Degenerate BESS model (assuming that the beam energy spread is less than their mass splitting). We also examine the most effective procedures for nearly degenerate resonances, and apply these to the case of Degenerate BESS resonances with mass splitting of order the beam energy spread.
2205.15758
Anderson Kohara
Hiren Kakkad, Anderson Kendi Kohara, Piotr Kotko
Evolution equation for elastic scattering of hadrons
6 pages, 3 figures and 2 tables
null
10.1140/epjc/s10052-022-10747-6
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We turn high energy elastic scattering of hadrons into an initial value problem using an evolution equation based on the Regge Field Theory, which has a form of the complex nonlinear reaction-diffusion equation, with time being played by the logarithm of energy. The initial conditions are provided by the data-driven models for the real and imaginary parts of the amplitude. Numerical calculations of pp differential cross sections and forward quantities for LHC energies agree very well with experimental data extending up to, and including the diffractive cone. Furthermore, we show that at current accessible energies the non-linear effects play an important role, as the impact parameter space profiles approach the unitarity bound. The equation also predicts some other effects discussed in the literature, like the hollowness of nuclear matter or existence of stationary points in momentum transfer t.
[ { "created": "Tue, 31 May 2022 12:49:08 GMT", "version": "v1" }, { "created": "Thu, 4 Aug 2022 10:29:48 GMT", "version": "v2" } ]
2022-09-28
[ [ "Kakkad", "Hiren", "" ], [ "Kohara", "Anderson Kendi", "" ], [ "Kotko", "Piotr", "" ] ]
We turn high energy elastic scattering of hadrons into an initial value problem using an evolution equation based on the Regge Field Theory, which has a form of the complex nonlinear reaction-diffusion equation, with time being played by the logarithm of energy. The initial conditions are provided by the data-driven models for the real and imaginary parts of the amplitude. Numerical calculations of pp differential cross sections and forward quantities for LHC energies agree very well with experimental data extending up to, and including the diffractive cone. Furthermore, we show that at current accessible energies the non-linear effects play an important role, as the impact parameter space profiles approach the unitarity bound. The equation also predicts some other effects discussed in the literature, like the hollowness of nuclear matter or existence of stationary points in momentum transfer t.
0902.3059
Iosif Khriplovich
A.G. Grozin, I.B. Khriplovich, and A.S. Rudenko
Upper limits on electric dipole moments of tau-lepton, heavy quarks, and W-boson
8 pages, 7 figures; misprint corrected, results do not change
Nucl.Phys.B821:285-290,2009
10.1016/j.nuclphysb.2009.06.026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss upper limits on the electric dipole moments (EDM) of the tau-lepton, heavy quarks, and W-boson, which follow from the precision measurements of the electron and neutron EDM.
[ { "created": "Wed, 18 Feb 2009 19:16:41 GMT", "version": "v1" }, { "created": "Wed, 4 Mar 2009 13:45:53 GMT", "version": "v2" } ]
2009-08-11
[ [ "Grozin", "A. G.", "" ], [ "Khriplovich", "I. B.", "" ], [ "Rudenko", "A. S.", "" ] ]
We discuss upper limits on the electric dipole moments (EDM) of the tau-lepton, heavy quarks, and W-boson, which follow from the precision measurements of the electron and neutron EDM.
hep-ph/9208260
null
K. S. Babu and R. R. Volkas
Bounds on mini-charged neutrinos in the minimal standard model
13 pages, LaTeX, UM-P-92/27
Phys.Rev.D46:2764-2768,1992
10.1103/PhysRevD.46.R2764
null
hep-ph
null
In the minimal Standard Model (MSM) with three generations of quarks and leptons, neutrinos can have tiny charges consistent with electromagnetic gauge invariance. There are three types of non-standard electric charge, given by $Q_{st} + \epsilon(L_i - L_j)$, where $i, j = e, \mu, \tau$ $(i \neq j)$, $Q_{st}$ is standard electric charge, $L_i$ is a family-lepton--number, and $\epsilon$ is an arbitrary parameter which is put equal to zero in the usual incarnation of the MSM. These three non-standard electric charges are of considerable theoretical interest because they are compatible with the MSM Lagrangian and $SU(3)_c \otimes SU(2)_L \otimes U(1)_Y$ gauge anomaly cancellation. The two most conspicuous implications of such non-standard electric charges are the presence of two generations of massless charged neutrinos and a breakdown in electromagnetic universality for $e$, $\mu$ and $\tau$. We use results from (i) charge conservation in $\beta$-decay, (ii) physical consequences of charged atoms in various contexts, (iii) the anomalous magnetic moments of charged leptons, (iv) neutrino-electron scattering, (v) energy loss in red giant and white dwarf stars, and (vi) limits on a cosmologically induced thermal photon mass, to place bounds on $\epsilon$. While the constraints derived for $\epsilon$ 10^{-21}$), the $L_{\mu}-L_{\tau}$ case allows $\epsilon$ to be as large as $10^{-14}$.
[ { "created": "Mon, 31 Aug 1992 06:00:41 GMT", "version": "v1" } ]
2009-12-30
[ [ "Babu", "K. S.", "" ], [ "Volkas", "R. R.", "" ] ]
In the minimal Standard Model (MSM) with three generations of quarks and leptons, neutrinos can have tiny charges consistent with electromagnetic gauge invariance. There are three types of non-standard electric charge, given by $Q_{st} + \epsilon(L_i - L_j)$, where $i, j = e, \mu, \tau$ $(i \neq j)$, $Q_{st}$ is standard electric charge, $L_i$ is a family-lepton--number, and $\epsilon$ is an arbitrary parameter which is put equal to zero in the usual incarnation of the MSM. These three non-standard electric charges are of considerable theoretical interest because they are compatible with the MSM Lagrangian and $SU(3)_c \otimes SU(2)_L \otimes U(1)_Y$ gauge anomaly cancellation. The two most conspicuous implications of such non-standard electric charges are the presence of two generations of massless charged neutrinos and a breakdown in electromagnetic universality for $e$, $\mu$ and $\tau$. We use results from (i) charge conservation in $\beta$-decay, (ii) physical consequences of charged atoms in various contexts, (iii) the anomalous magnetic moments of charged leptons, (iv) neutrino-electron scattering, (v) energy loss in red giant and white dwarf stars, and (vi) limits on a cosmologically induced thermal photon mass, to place bounds on $\epsilon$. While the constraints derived for $\epsilon$ 10^{-21}$), the $L_{\mu}-L_{\tau}$ case allows $\epsilon$ to be as large as $10^{-14}$.
hep-ph/0612222
Hiroshi Nunokawa
Hiroshi Nunokawa
Resolving the Octant theta(23) Degeneracy by Neutrino Oscillation Experiments
3 pages, 4 figures, talk given at NOW2006, Otrant, Lecce, Italy, September 9-16, 2006
Nucl.Phys.Proc.Suppl.168:212-214,2007
10.1016/j.nuclphysbps.2007.02.080
null
hep-ph
null
We discuss how and to what extent the degeneracy associated with theta(23), if it's not maximal, can be resolved by future oscillation experiments which utilize conventional neutrino beam from accelerator and/or reactor neutrinos.
[ { "created": "Tue, 19 Dec 2006 03:50:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nunokawa", "Hiroshi", "" ] ]
We discuss how and to what extent the degeneracy associated with theta(23), if it's not maximal, can be resolved by future oscillation experiments which utilize conventional neutrino beam from accelerator and/or reactor neutrinos.
hep-ph/0404034
Johannes Bluemlein
Sergey I. Alekhin and Johannes Bl\"umlein
Mellin Representation for the Heavy Flavor Contributions to Deep Inelastic Structure Functions
13 pages Letex, 1 style file, 10 eps figures
Phys.Lett. B594 (2004) 299-307
10.1016/j.physletb.2004.05.042
DESY 03-204, SFB-CPP/04-02
hep-ph hep-ex
null
We derive semi--analytic expressions for the analytic continuation of the Mellin transforms of the heavy flavor QCD coefficient functions for neutral current deep inelastic scattering in leading and next-to-leading order to complex values of the Mellin variable $N$. These representations are used in Mellin--space QCD evolution programs to provide fast evaluations of the heavy flavor contributions to the structure functions $F_2(x,Q^2), F_L(x,Q^2)$ and $g_1(x,Q^2)$.
[ { "created": "Sun, 4 Apr 2004 06:07:09 GMT", "version": "v1" } ]
2010-04-05
[ [ "Alekhin", "Sergey I.", "" ], [ "Blümlein", "Johannes", "" ] ]
We derive semi--analytic expressions for the analytic continuation of the Mellin transforms of the heavy flavor QCD coefficient functions for neutral current deep inelastic scattering in leading and next-to-leading order to complex values of the Mellin variable $N$. These representations are used in Mellin--space QCD evolution programs to provide fast evaluations of the heavy flavor contributions to the structure functions $F_2(x,Q^2), F_L(x,Q^2)$ and $g_1(x,Q^2)$.
2212.06852
T\'essio B. De Melo
Asmaa Abada, Nicol\'as Bernal, Antonio E. C\'arcamo Hern\'andez, Sergey Kovalenko, T\'essio B. de Melo, Takashi Toma
Phenomenological and cosmological implications of a scotogenic three-loop neutrino mass model
30 pages, 5 figures. Extended discussion on the muon g-2. Matches published version in JHEP
null
10.1007/JHEP03(2023)035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a scotogenic model for generating neutrino masses through a three-loop seesaw. It is a minimally extended inert doublet model with a spontaneously broken global symmetry $U(1)'$ and a preserved $\mathbb{Z}_2$ symmetry. The three-loop suppression allows the new particles to have masses at the TeV scale without fine-tuning the Yukawa couplings. The model leads to a rich phenomenology while satisfying all the current constraints imposed by neutrinoless double-beta decay, charged-lepton flavor violation, and electroweak precision observables. The relatively large Yukawa couplings lead to sizable rates for charged lepton flavor violation processes, well within future experimental reach. The model could also successfully explain the $W$ mass anomaly and provides viable fermionic or scalar dark matter candidates.
[ { "created": "Tue, 13 Dec 2022 19:00:05 GMT", "version": "v1" }, { "created": "Wed, 8 Mar 2023 18:57:01 GMT", "version": "v2" } ]
2023-03-22
[ [ "Abada", "Asmaa", "" ], [ "Bernal", "Nicolás", "" ], [ "Hernández", "Antonio E. Cárcamo", "" ], [ "Kovalenko", "Sergey", "" ], [ "de Melo", "Téssio B.", "" ], [ "Toma", "Takashi", "" ] ]
We propose a scotogenic model for generating neutrino masses through a three-loop seesaw. It is a minimally extended inert doublet model with a spontaneously broken global symmetry $U(1)'$ and a preserved $\mathbb{Z}_2$ symmetry. The three-loop suppression allows the new particles to have masses at the TeV scale without fine-tuning the Yukawa couplings. The model leads to a rich phenomenology while satisfying all the current constraints imposed by neutrinoless double-beta decay, charged-lepton flavor violation, and electroweak precision observables. The relatively large Yukawa couplings lead to sizable rates for charged lepton flavor violation processes, well within future experimental reach. The model could also successfully explain the $W$ mass anomaly and provides viable fermionic or scalar dark matter candidates.
1610.05962
Pedro Simoni Pasquini
Pedro Pasquini, S. C. Chuli\'a and J. W. F. Valle
Neutrino oscillations from warped flavor symmetry: predictions for long baseline experiments T2K, NOvA and DUNE
12 pages, 15 figures, 1 table, latex
Phys. Rev. D 95, 095030 (2017)
10.1103/PhysRevD.95.095030
IFIC/16-72
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Here we study the pattern of neutrino oscillations emerging from a previously proposed warped model construction incorporating $\Delta(27)$ flavor symmetry. In addition to a complete description of fermion masses, the model predicts the lepton mixing matrix in terms of two parameters. The good measurement of $\theta_{13}$ makes these two parameters nearly proportional, leading to an approximate one-parameter description of neutrino oscillations. There is a sharp fourfold degenerate correlation between $\delta_{CP}$ and the atmospheric mixing angle $\theta_{23}$, so that maximal $\theta_{23}$ also implies maximal leptonic CP violation. The predicted electron neutrino and anti-neutrino appearance probabilities indicate that the model should be tested at the T2K, NO$\nu$A and DUNE long baseline oscillation experiments.
[ { "created": "Wed, 19 Oct 2016 11:19:11 GMT", "version": "v1" } ]
2017-06-07
[ [ "Pasquini", "Pedro", "" ], [ "Chuliá", "S. C.", "" ], [ "Valle", "J. W. F.", "" ] ]
Here we study the pattern of neutrino oscillations emerging from a previously proposed warped model construction incorporating $\Delta(27)$ flavor symmetry. In addition to a complete description of fermion masses, the model predicts the lepton mixing matrix in terms of two parameters. The good measurement of $\theta_{13}$ makes these two parameters nearly proportional, leading to an approximate one-parameter description of neutrino oscillations. There is a sharp fourfold degenerate correlation between $\delta_{CP}$ and the atmospheric mixing angle $\theta_{23}$, so that maximal $\theta_{23}$ also implies maximal leptonic CP violation. The predicted electron neutrino and anti-neutrino appearance probabilities indicate that the model should be tested at the T2K, NO$\nu$A and DUNE long baseline oscillation experiments.
1211.6332
Agustin Sabio Vera
G. Chachamis, A. Sabio Vera, C. Salas
Bootstrap and momentum transfer dependence in small x evolution equations
null
null
10.1103/PhysRevD.87.016007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using Monte Carlo integration techniques, we investigate running coupling effects compatible with the high energy bootstrap condition to all orders in the strong coupling in evolution equations valid at small values of Bjorken x in deep inelastic scattering. A model for the running of the coupling with analytic behavior in the infrared region and compatible with power corrections to jet observables is used. As a difference to the fixed coupling case, where the momentum transfer acts as an effective strong cut-off of the diffusion to infrared scales, in our running coupling study the dependence on the momentum transfer is much milder.
[ { "created": "Tue, 27 Nov 2012 15:53:09 GMT", "version": "v1" } ]
2013-05-30
[ [ "Chachamis", "G.", "" ], [ "Vera", "A. Sabio", "" ], [ "Salas", "C.", "" ] ]
Using Monte Carlo integration techniques, we investigate running coupling effects compatible with the high energy bootstrap condition to all orders in the strong coupling in evolution equations valid at small values of Bjorken x in deep inelastic scattering. A model for the running of the coupling with analytic behavior in the infrared region and compatible with power corrections to jet observables is used. As a difference to the fixed coupling case, where the momentum transfer acts as an effective strong cut-off of the diffusion to infrared scales, in our running coupling study the dependence on the momentum transfer is much milder.
0711.2428
Philippe Brax
Philippe Brax
Embedding Dark Energy in Supergravity
7 pages,to appear in the conference proceedings of the 9th workshop on non-perturbative QCD, Institut d'Astrophysique de Paris, 4-8 June 2007
ECONFC0706044:24,2007
null
null
hep-ph
null
We give a brief overview of some of the constraints on the embedding of dark energy in supergravity.
[ { "created": "Thu, 15 Nov 2007 14:50:06 GMT", "version": "v1" } ]
2008-11-26
[ [ "Brax", "Philippe", "" ] ]
We give a brief overview of some of the constraints on the embedding of dark energy in supergravity.
2204.09569
Eligio Lisi
Eligio Lisi and Antonio Marrone
Majorana neutrino mass constraints in the landscape of nuclear matrix elements
Minor clarifications and additions in the text. Matches published version, Phys. Rev. D 106 (2022) 1, 013009
null
10.1103/PhysRevD.106.013009
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We discuss up-to-date constraints on the Majorana neutrino mass $m_{\beta\beta}$ from neutrinoless double beta decay ($0\nu\beta\beta$) searches in experiments using different isotopes: KamLAND-Zen and EXO ($^{136}$Xe), GERDA and MAJORANA ($^{76}$Ge) and CUORE ($^{130}$Te). Best fits and upper bounds on $m_{\beta\beta}$ are explored in the general landscape of nuclear matrix elements (NME), as well as for specific NME values obtained in representative nuclear models. By approximating the likelihood of $0\nu\beta\beta$ signals through quadratic forms, the analysis of separate and combined isotope data becomes exceedingly simple, and allows to clarify various aspects of multi-isotope data combinations. In particular, we analyze the relative impact of different data in setting upper bounds on $m_{\beta\beta}$, as well as the conditions leading to nonzero $m_{\beta\beta}$ at best fit, for variable values of the NMEs. Detailed results on $m_{\beta\beta}$ from various combinations of data are reported in graphical and numerical form. Implications for future $0\nu\beta\beta$ data analyses and NME calculations are briefly discussed.
[ { "created": "Wed, 20 Apr 2022 16:09:49 GMT", "version": "v1" }, { "created": "Wed, 8 Feb 2023 16:01:17 GMT", "version": "v2" } ]
2023-02-09
[ [ "Lisi", "Eligio", "" ], [ "Marrone", "Antonio", "" ] ]
We discuss up-to-date constraints on the Majorana neutrino mass $m_{\beta\beta}$ from neutrinoless double beta decay ($0\nu\beta\beta$) searches in experiments using different isotopes: KamLAND-Zen and EXO ($^{136}$Xe), GERDA and MAJORANA ($^{76}$Ge) and CUORE ($^{130}$Te). Best fits and upper bounds on $m_{\beta\beta}$ are explored in the general landscape of nuclear matrix elements (NME), as well as for specific NME values obtained in representative nuclear models. By approximating the likelihood of $0\nu\beta\beta$ signals through quadratic forms, the analysis of separate and combined isotope data becomes exceedingly simple, and allows to clarify various aspects of multi-isotope data combinations. In particular, we analyze the relative impact of different data in setting upper bounds on $m_{\beta\beta}$, as well as the conditions leading to nonzero $m_{\beta\beta}$ at best fit, for variable values of the NMEs. Detailed results on $m_{\beta\beta}$ from various combinations of data are reported in graphical and numerical form. Implications for future $0\nu\beta\beta$ data analyses and NME calculations are briefly discussed.
0907.4549
Achilleas Vamvasakis
Achilleas Vamvasakis
Phenomenology and Cosmology of Supersymmetric Grand Unified Theories
99 pages including 11 figures
null
null
UT-STPD-1-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the major objectives of this dissertation has been the seek for inflationary models, coming from supersymmetric theories, which are compatible with recent cosmological data and, more specifically, with measurements of the spectral index from the WMAP3 data. A particular particle physics model, the extended SUSY Pati-Salam model with Yukawa quasi-unification, was examined thoroughly with respect to its cosmology and it was found that it incorporates a number of inflationary scenarios which can become compatible with recent data. The study of these scenarios brought out variations of cosmological models which might be important in cosmological research.
[ { "created": "Mon, 27 Jul 2009 06:28:30 GMT", "version": "v1" } ]
2009-07-28
[ [ "Vamvasakis", "Achilleas", "" ] ]
One of the major objectives of this dissertation has been the seek for inflationary models, coming from supersymmetric theories, which are compatible with recent cosmological data and, more specifically, with measurements of the spectral index from the WMAP3 data. A particular particle physics model, the extended SUSY Pati-Salam model with Yukawa quasi-unification, was examined thoroughly with respect to its cosmology and it was found that it incorporates a number of inflationary scenarios which can become compatible with recent data. The study of these scenarios brought out variations of cosmological models which might be important in cosmological research.
0801.2539
Dan Hooper
Dan Hooper, Tilman Plehn and Alberto Vallinotto
Neutralino Dark Matter and Trilepton Searches in the MSSM
13 pages, 14 figures
Phys.Rev.D77:095014,2008
10.1103/PhysRevD.77.095014
FERMILAB-PUB-07-666-A
hep-ph astro-ph
null
Searches for supersymmetry are among the most exciting physics goals at Run II of the Tevatron. In particular, in supersymmetric models with light charginos, neutralinos and sleptons, associated chargino--neutralino production can potentially be observed as multi-lepton events with missing energy. We discuss how, in the generic TeV-scale MSSM, the prospects for these chargino-neutralino searches are impacted by cosmological considerations, namely the neutralino relic abundance and direct detection limits. We also discuss what an observation of chargino-neutralino production at the Tevatron would imply for the prospects of future direct dark matter searches without assuming specific patterns of supersymmetry breaking.
[ { "created": "Wed, 16 Jan 2008 17:17:31 GMT", "version": "v1" } ]
2008-11-26
[ [ "Hooper", "Dan", "" ], [ "Plehn", "Tilman", "" ], [ "Vallinotto", "Alberto", "" ] ]
Searches for supersymmetry are among the most exciting physics goals at Run II of the Tevatron. In particular, in supersymmetric models with light charginos, neutralinos and sleptons, associated chargino--neutralino production can potentially be observed as multi-lepton events with missing energy. We discuss how, in the generic TeV-scale MSSM, the prospects for these chargino-neutralino searches are impacted by cosmological considerations, namely the neutralino relic abundance and direct detection limits. We also discuss what an observation of chargino-neutralino production at the Tevatron would imply for the prospects of future direct dark matter searches without assuming specific patterns of supersymmetry breaking.
1710.02461
Yohei Ema
Yohei Ema, Kazunori Nakayama
Explosive Axion Production from Saxion
17 pages, 3 figures
null
10.1016/j.physletb.2017.11.035
UT-17-31
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dynamics of saxion in a supersymmetric axion model and its effect on the axion production is studied in detail. We find that the axion production is very efficient when the saxion oscillation amplitude is much larger than the Peccei-Quinn scale, due to a spike-like behavior of the effective axion mass. We also consider the axino production and several cosmological consequences. The possibility of detection of gravitational waves from the non-linear dynamics of the saxion and axion is discussed.
[ { "created": "Fri, 6 Oct 2017 15:49:00 GMT", "version": "v1" } ]
2018-01-17
[ [ "Ema", "Yohei", "" ], [ "Nakayama", "Kazunori", "" ] ]
The dynamics of saxion in a supersymmetric axion model and its effect on the axion production is studied in detail. We find that the axion production is very efficient when the saxion oscillation amplitude is much larger than the Peccei-Quinn scale, due to a spike-like behavior of the effective axion mass. We also consider the axino production and several cosmological consequences. The possibility of detection of gravitational waves from the non-linear dynamics of the saxion and axion is discussed.
hep-ph/9811228
Valery Sinev
L.A.Mikaelyan, V.V.Sinev
Searches for Sterile Neutrinos at Reactor
8 pages, LaTeX 2.09, 3 Postscript figures. Talk presented at RAS Nuclear Physics Department Conference, Moscow, November, 1998
Phys.Atom.Nucl.62:2008-2012,1999; Yad.Fiz.62:2177-2181,1999
null
null
hep-ph
null
We show that in a reactor disappearance oscillation experiment the sensitivity to the mixing parameter can be substantially improved for $(1 - 5\cdot10^{-4}) eV^{2}$ mass parameter range which includes both the LSND and the atmospheric neutrino oscillation regions. The objectives are: to search for the sterile neutrinos and to get a better understanding of the atmospheric neutrino oscillation mechanism. The parameters of the underground (600 m.w.e.) Krasnoyarsk reactor and data from the CHOOZ reactor oscillation experiment are used to estimate the effect and background rates.
[ { "created": "Tue, 3 Nov 1998 10:33:09 GMT", "version": "v1" }, { "created": "Thu, 5 Nov 1998 09:08:00 GMT", "version": "v2" }, { "created": "Wed, 18 Nov 1998 07:19:02 GMT", "version": "v3" } ]
2011-04-15
[ [ "Mikaelyan", "L. A.", "" ], [ "Sinev", "V. V.", "" ] ]
We show that in a reactor disappearance oscillation experiment the sensitivity to the mixing parameter can be substantially improved for $(1 - 5\cdot10^{-4}) eV^{2}$ mass parameter range which includes both the LSND and the atmospheric neutrino oscillation regions. The objectives are: to search for the sterile neutrinos and to get a better understanding of the atmospheric neutrino oscillation mechanism. The parameters of the underground (600 m.w.e.) Krasnoyarsk reactor and data from the CHOOZ reactor oscillation experiment are used to estimate the effect and background rates.
0905.2739
Srubabati Goswami
Srubabati Goswami, Subrata Khan, Werner Rodejohann
Minimal Textures in Seesaw Mass Matrices and their low and high Energy Phenomenology
Typos corrected
Phys.Lett.B680:255-262,2009
10.1016/j.physletb.2009.08.056
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In an attempt to find minimal scenarios we study the implications of Dirac and Majorana mass matrices with texture zeros within the type I seesaw mechanism. For the Dirac mass matrices we consider 5 zero textures which we show to be the most minimal form that can successfully account for low energy phenomenology if the Majorana mass matrices are chosen minimal as well. For those, we consider both diagonal and even more minimal non-diagonal forms. The latter can be motivated e.g. by simple U(1) flavour symmetries and have two degenerate eigenvalues. We classify the allowed textures and discuss the ramifications for leptogenesis and lepton flavour violation.
[ { "created": "Sun, 17 May 2009 14:00:32 GMT", "version": "v1" }, { "created": "Thu, 9 Jul 2009 09:01:08 GMT", "version": "v2" } ]
2009-11-19
[ [ "Goswami", "Srubabati", "" ], [ "Khan", "Subrata", "" ], [ "Rodejohann", "Werner", "" ] ]
In an attempt to find minimal scenarios we study the implications of Dirac and Majorana mass matrices with texture zeros within the type I seesaw mechanism. For the Dirac mass matrices we consider 5 zero textures which we show to be the most minimal form that can successfully account for low energy phenomenology if the Majorana mass matrices are chosen minimal as well. For those, we consider both diagonal and even more minimal non-diagonal forms. The latter can be motivated e.g. by simple U(1) flavour symmetries and have two degenerate eigenvalues. We classify the allowed textures and discuss the ramifications for leptogenesis and lepton flavour violation.
hep-ph/0610005
Yue Chongxing
Chong-Xing Yue, Li Li, Shuo Yang, and Li-Na Wang
Signals of the littlest Higgs model with T-parity at $e\gamma$ and $ep$ collisions
11 pages, 4 figures
null
null
null
hep-ph
null
Littlest Higgs model with T-parity predicts the existence of the neutral, weakly interacting, new gauge boson $B_{H}$, which can be seen as an attractive dark matter candidate. We study production of the new gauge boson $B_{H}$ via $e\gamma$ and $ep$ collisions. We find that $B_{H}$ can be abundantly produced via the subprocesses $e^{-}\gamma\to L^{-}B_{H}$ and $\gamma q\to B_{H}Q$, which might give rise to characteristic signals. Some discussions about the $SM$ backgrounds for this kind of signals are also given.
[ { "created": "Sat, 30 Sep 2006 07:01:03 GMT", "version": "v1" }, { "created": "Mon, 9 Oct 2006 00:17:22 GMT", "version": "v2" }, { "created": "Thu, 23 Nov 2006 00:12:32 GMT", "version": "v3" } ]
2007-05-23
[ [ "Yue", "Chong-Xing", "" ], [ "Li", "Li", "" ], [ "Yang", "Shuo", "" ], [ "Wang", "Li-Na", "" ] ]
Littlest Higgs model with T-parity predicts the existence of the neutral, weakly interacting, new gauge boson $B_{H}$, which can be seen as an attractive dark matter candidate. We study production of the new gauge boson $B_{H}$ via $e\gamma$ and $ep$ collisions. We find that $B_{H}$ can be abundantly produced via the subprocesses $e^{-}\gamma\to L^{-}B_{H}$ and $\gamma q\to B_{H}Q$, which might give rise to characteristic signals. Some discussions about the $SM$ backgrounds for this kind of signals are also given.
0912.1173
Yutaka Hosotani
Yutaka Hosotani, Shusaku Noda and Nobuhiro Uekusa
The electroweak gauge couplings in SO(5) x U(1) gauge-Higgs unification
42 pages, 2 figures. Many comments and references are added
Prog.Theor.Phys.123:757-790,2010
10.1143/PTP.123.757
OU-HET 649/2009
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The electroweak currents of quarks and leptons in the $SO(5) \times U(1)$ gauge-Higgs unification model in the Randall-Sundrum warped space are determined. The 4D gauge couplings deviate from those in the standard model and the weak universality is slightly violated. It is shown that the model is free from 4D anomalies and the deviations of the gauge couplings are tiny, less than 1% except for the top quark. The $Zt_L \bar t_L$, $Zt_R \bar t_R$, $Zb_L \bar b_L$ and $Zb_R \bar b_R$ couplings deviate from those in the standard model by -7%, 18%, 0.3% and 0.9% with the warp factor $z_L = 10^{15}$, respectively. The violation of the $\mu$-$e$, $\tau$-$e$ and $t$-$e$ universality in the charged current interactions is ${\cal O}(10^{-8})$, ${\cal O}(10^{-6})$ and 2.3%, respectively.
[ { "created": "Mon, 7 Dec 2009 07:01:11 GMT", "version": "v1" }, { "created": "Wed, 24 Feb 2010 07:41:41 GMT", "version": "v2" } ]
2014-11-20
[ [ "Hosotani", "Yutaka", "" ], [ "Noda", "Shusaku", "" ], [ "Uekusa", "Nobuhiro", "" ] ]
The electroweak currents of quarks and leptons in the $SO(5) \times U(1)$ gauge-Higgs unification model in the Randall-Sundrum warped space are determined. The 4D gauge couplings deviate from those in the standard model and the weak universality is slightly violated. It is shown that the model is free from 4D anomalies and the deviations of the gauge couplings are tiny, less than 1% except for the top quark. The $Zt_L \bar t_L$, $Zt_R \bar t_R$, $Zb_L \bar b_L$ and $Zb_R \bar b_R$ couplings deviate from those in the standard model by -7%, 18%, 0.3% and 0.9% with the warp factor $z_L = 10^{15}$, respectively. The violation of the $\mu$-$e$, $\tau$-$e$ and $t$-$e$ universality in the charged current interactions is ${\cal O}(10^{-8})$, ${\cal O}(10^{-6})$ and 2.3%, respectively.
hep-ph/9909247
null
Keith A. Olive
Cosmology II: From the Planck Time to BBN
17 pages, latex, Summary of talk given at the David N. Schramm Memorial Symposium: Inner Space/Outer Space II, Fermilab, May 1999
null
null
UMN-TH-1814/99, TPI-MINN-99/39
hep-ph astro-ph
null
Progress in early Universe cosmology, including strings, extra dimensions, inflation, phase transitions, and baryogenesis, is reviewed.
[ { "created": "Fri, 3 Sep 1999 17:53:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Olive", "Keith A.", "" ] ]
Progress in early Universe cosmology, including strings, extra dimensions, inflation, phase transitions, and baryogenesis, is reviewed.
hep-ph/0112317
Gsponer
Andre Gsponer, and Jean-Pierre Hurni
Lanczos's equation to replace Dirac's equation ?
7 pages. Version 2 with an errata
Published in J.D. Brown et al., eds., Proceedings of the Cornelius Lanczos International Centenary Conference, Raleigh, North Carolina, December 12--17, 1993 (ISBN 0-89871-339-0, SIAM, Philadelphia, 1994) 509--512
null
Independent Scientific Research Institute report number ISRI-94-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lanczos's quaternionic interpretation of Dirac's equation provides a unified description for all elementary particles of spin 0, 1/2, 1, and 3/2. The Lagrangian formulation given by Einstein and Mayer in 1933 predicts two main classes of solutions. (1) Point like partons which come in two families, quarks and leptons. The correct fractional or integral electric and baryonic charges, and zero mass for the neutrino and the u-quark, are set by eigenvalue equations. The electro-weak interaction of the partons is the same as with the Standard model, with the same two free parameters: e and sin^2 theta. There is no need for a Higgs symmetry breaking mechanism. (2) Extended hadrons for which there is no simple eigenvalue equation for the mass. The strong interaction is essentially non-local. The pion mass and pion-nucleon coupling constant determine to first order the nucleon size, mass and anomalous magnetic moment.
[ { "created": "Sun, 23 Dec 2001 04:05:49 GMT", "version": "v1" }, { "created": "Sat, 18 Oct 2008 17:39:33 GMT", "version": "v2" } ]
2008-10-18
[ [ "Gsponer", "Andre", "" ], [ "Hurni", "Jean-Pierre", "" ] ]
Lanczos's quaternionic interpretation of Dirac's equation provides a unified description for all elementary particles of spin 0, 1/2, 1, and 3/2. The Lagrangian formulation given by Einstein and Mayer in 1933 predicts two main classes of solutions. (1) Point like partons which come in two families, quarks and leptons. The correct fractional or integral electric and baryonic charges, and zero mass for the neutrino and the u-quark, are set by eigenvalue equations. The electro-weak interaction of the partons is the same as with the Standard model, with the same two free parameters: e and sin^2 theta. There is no need for a Higgs symmetry breaking mechanism. (2) Extended hadrons for which there is no simple eigenvalue equation for the mass. The strong interaction is essentially non-local. The pion mass and pion-nucleon coupling constant determine to first order the nucleon size, mass and anomalous magnetic moment.
hep-ph/9409376
Marek Karliner
John Ellis, Marek Karliner, Mark A. Samuel and Eric Steinfelds
The Anomalous Magnetic Moments of the Electron and the Muon - Improved QED Predictions Using Pade Approximants
8 pages (LateX); SLAC-PUB-6670, CERN-TH-7451/94, TAUP-2201-94, OSU-RN-393/94. Typo corrected
null
null
null
hep-ph
null
We use Pade Approximants to obtain improved predictions for the anomalous magnetic moments of the electron and the muon. These are needed because of the very precise experimental values presently obtained for the electron, and soon to be obtained at BNL for the muon. The Pade prediction for the QED contribution to the anomalous magnetic moment of the muon differs significantly from the naive perturbative prediction.
[ { "created": "Wed, 21 Sep 1994 16:23:00 GMT", "version": "v1" }, { "created": "Thu, 22 Sep 1994 14:09:00 GMT", "version": "v2" } ]
2008-02-03
[ [ "Ellis", "John", "" ], [ "Karliner", "Marek", "" ], [ "Samuel", "Mark A.", "" ], [ "Steinfelds", "Eric", "" ] ]
We use Pade Approximants to obtain improved predictions for the anomalous magnetic moments of the electron and the muon. These are needed because of the very precise experimental values presently obtained for the electron, and soon to be obtained at BNL for the muon. The Pade prediction for the QED contribution to the anomalous magnetic moment of the muon differs significantly from the naive perturbative prediction.
1708.00800
Scientific Information Service CERN
R. Rosenfeld
Physics Beyond the Standard Model
5 pages, contribution to the CERN-Latin-American School of High-Energy Physics, Ibarra, Ecuador, 4 - 17 March 2015,
CERN Yellow Report CERN 2016-005, pp. 159-164
10.5170/CERN-2016-005.159
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In these three lectures I review the need to go beyond the Standard Glashow- Weinberg-Salam Model and discuss some of the approaches that are explored in this direction.
[ { "created": "Wed, 2 Aug 2017 15:42:01 GMT", "version": "v1" } ]
2017-08-03
[ [ "Rosenfeld", "R.", "" ] ]
In these three lectures I review the need to go beyond the Standard Glashow- Weinberg-Salam Model and discuss some of the approaches that are explored in this direction.
0907.3044
Karim Ghorbani
Karim Ghorbani
$K_{S}$ $\to$ $\gamma \gamma$ at one-loop revisited
9 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have calculated the decay amplitude for the process $K_{S}$ $\to$ $\gamma \gamma$ at one loop order in chiral perturbation theory. As a new improvement we have included the weak mass term which is only relevant for processes with external fields in the final state. This term was ignored in earlier publications for this decay. We find that the inclusion of $G_{8}^{\prime}$ brings the theoretical decay rate into a good agreement with experiment.
[ { "created": "Fri, 17 Jul 2009 11:14:44 GMT", "version": "v1" } ]
2009-07-20
[ [ "Ghorbani", "Karim", "" ] ]
We have calculated the decay amplitude for the process $K_{S}$ $\to$ $\gamma \gamma$ at one loop order in chiral perturbation theory. As a new improvement we have included the weak mass term which is only relevant for processes with external fields in the final state. This term was ignored in earlier publications for this decay. We find that the inclusion of $G_{8}^{\prime}$ brings the theoretical decay rate into a good agreement with experiment.