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1302.1993
Rainer Stiele
Lisa M. Haas, Rainer Stiele, Jens Braun, Jan M. Pawlowski, Juergen Schaffner-Bielich
Improved Polyakov-loop potential for effective models from functional calculations
19 pages, 25 figures; version published in Phys. Rev. D
PhysRevD.87.076004,2013
10.1103/PhysRevD.87.076004
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the quark backreaction on the Polyakov loop and its impact on the thermodynamics of quantum chromodynamics. The dynamics of the gluons generating the Polyakov-loop potential is altered by the presence of dynamical quarks. However, this backreaction of the quarks has not yet been taken into account in Polyakov-loop extended model studies. In the present work, we show within a 2+1 flavour Polyakov-quark-meson model that a quark-improved Polyakov-loop potential leads to a smoother transition between the low-temperature hadronic phase and the high-temperature quark-gluon plasma phase. In particular, we discuss the dependence of our results on the remaining uncertainties that are the critical temperature and the parametrisation of the Polyakov-loop potential as well as the mass of the sigma-meson.
[ { "created": "Fri, 8 Feb 2013 11:03:47 GMT", "version": "v1" }, { "created": "Thu, 11 Apr 2013 20:59:34 GMT", "version": "v2" } ]
2013-04-15
[ [ "Haas", "Lisa M.", "" ], [ "Stiele", "Rainer", "" ], [ "Braun", "Jens", "" ], [ "Pawlowski", "Jan M.", "" ], [ "Schaffner-Bielich", "Juergen", "" ] ]
We investigate the quark backreaction on the Polyakov loop and its impact on the thermodynamics of quantum chromodynamics. The dynamics of the gluons generating the Polyakov-loop potential is altered by the presence of dynamical quarks. However, this backreaction of the quarks has not yet been taken into account in Polyakov-loop extended model studies. In the present work, we show within a 2+1 flavour Polyakov-quark-meson model that a quark-improved Polyakov-loop potential leads to a smoother transition between the low-temperature hadronic phase and the high-temperature quark-gluon plasma phase. In particular, we discuss the dependence of our results on the remaining uncertainties that are the critical temperature and the parametrisation of the Polyakov-loop potential as well as the mass of the sigma-meson.
hep-ph/9507373
George Siopsis
George Siopsis (The University of Tennessee, Knoxville)
On final-state effects in t-tbar production at threshold
12 pp. incl. 4 figures (RevTeX with epic, eepic and axodraw), to be published in Phys. Lett. B
Phys.Lett. B358 (1995) 360-364
10.1016/0370-2693(95)01037-Q
UTHEP-95-0103
hep-ph
null
We apply the relativistic Bethe-Salpeter formalism to the calculation of final-state effects in the production of a t-tbar pair at threshold. We find that final-state rescattering does not affect the momentum distribution of the t-tbar pair to lowest order in the strong coupling constant. This result correctly extends earlier results based on the non-relativistic Lippmann-Schwinger equation.
[ { "created": "Fri, 21 Jul 1995 15:25:00 GMT", "version": "v1" } ]
2009-10-28
[ [ "Siopsis", "George", "", "The University of Tennessee, Knoxville" ] ]
We apply the relativistic Bethe-Salpeter formalism to the calculation of final-state effects in the production of a t-tbar pair at threshold. We find that final-state rescattering does not affect the momentum distribution of the t-tbar pair to lowest order in the strong coupling constant. This result correctly extends earlier results based on the non-relativistic Lippmann-Schwinger equation.
2209.14033
Juan Antonio Aguilar-Saavedra
J. A. Aguilar-Saavedra
Laboratory-frame tests of quantum entanglement in $H \to WW$
LaTeX 7 pages. Added some discussions and an estimation of theoretical uncertainties. Final version published in PRD, with a typo fixed
null
10.1103/PhysRevD.107.076016
IFT-UAM/CSIC-22-119
hep-ph hep-ex quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum entanglement between the two $W$ bosons resulting from the decay of a Higgs boson may be investigated in the dilepton channel $H \to WW \to \ell \nu \ell \nu$ using laboratory-frame observables that only involve the charged leptons $\ell=e,\mu$. The dilepton invariant mass distribution, already measured by the ATLAS and CMS Collaborations at the LHC, can be used to observe the quantum entanglement of the $WW$ pair with a statistical sensitivity of $7\sigma$ with Run 2 data, and of $6\sigma$ when including theoretical systematics. As a by-product, the relation between $W$ rest frame (four-dimensional) angular distributions, $H \to WW$ decay amplitudes, and spin correlation coefficients, is written down.
[ { "created": "Wed, 28 Sep 2022 12:22:12 GMT", "version": "v1" }, { "created": "Thu, 27 Apr 2023 06:21:44 GMT", "version": "v2" } ]
2023-05-03
[ [ "Aguilar-Saavedra", "J. A.", "" ] ]
Quantum entanglement between the two $W$ bosons resulting from the decay of a Higgs boson may be investigated in the dilepton channel $H \to WW \to \ell \nu \ell \nu$ using laboratory-frame observables that only involve the charged leptons $\ell=e,\mu$. The dilepton invariant mass distribution, already measured by the ATLAS and CMS Collaborations at the LHC, can be used to observe the quantum entanglement of the $WW$ pair with a statistical sensitivity of $7\sigma$ with Run 2 data, and of $6\sigma$ when including theoretical systematics. As a by-product, the relation between $W$ rest frame (four-dimensional) angular distributions, $H \to WW$ decay amplitudes, and spin correlation coefficients, is written down.
1912.11472
Qiaoli Yang
Qiaoli Yang, Shiqin Dong
Probing Dark Matter Axions using the Hyperfine Structure Splitting of Hydrogen Atoms
17 pages, 6 figures; Version published in Phys.Lett.B
Phys.Lett.B 843 (2023) 138004
10.1016/j.physletb.2023.138004
null
hep-ph hep-ex physics.atm-clus
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
QCD axions can be a substantial part of dark matter if their mass $m_a\sim10^{-5}$eV. Since the axions were created by the misalignment mechanism, their local energy spectrum density is large. Consequently, the axion-induced atomic transition rate is enhanced if the atomic energy gap matches the axion mass. The hyperfine splitting between the spin 0 singlet ground state and the spin 1 triplet state of hydrogen is $0.59\times10^{-5}$eV, which is close to the preferred mass of dark matter axions. With an energy gap adjustment by applying a weak Zeeman magnetic field, dark matter axions can induce atomic hydrogen transitions. Furthermore, because the total spins of the hydrogen triplet and singlet differ, the axion-induced transitions are detectable by a Stern--Gerlach apparatus or a sensitive magnetic field detector. A potential realization of the proposed scheme can be similar to existing hydrogen masers.
[ { "created": "Tue, 24 Dec 2019 18:54:26 GMT", "version": "v1" }, { "created": "Mon, 13 Jan 2020 17:15:33 GMT", "version": "v2" }, { "created": "Mon, 2 May 2022 09:12:00 GMT", "version": "v3" }, { "created": "Mon, 19 Sep 2022 16:35:24 GMT", "version": "v4" }, { "created": "Sat, 17 Jun 2023 14:13:42 GMT", "version": "v5" } ]
2023-06-21
[ [ "Yang", "Qiaoli", "" ], [ "Dong", "Shiqin", "" ] ]
QCD axions can be a substantial part of dark matter if their mass $m_a\sim10^{-5}$eV. Since the axions were created by the misalignment mechanism, their local energy spectrum density is large. Consequently, the axion-induced atomic transition rate is enhanced if the atomic energy gap matches the axion mass. The hyperfine splitting between the spin 0 singlet ground state and the spin 1 triplet state of hydrogen is $0.59\times10^{-5}$eV, which is close to the preferred mass of dark matter axions. With an energy gap adjustment by applying a weak Zeeman magnetic field, dark matter axions can induce atomic hydrogen transitions. Furthermore, because the total spins of the hydrogen triplet and singlet differ, the axion-induced transitions are detectable by a Stern--Gerlach apparatus or a sensitive magnetic field detector. A potential realization of the proposed scheme can be similar to existing hydrogen masers.
hep-ph/9707427
null
Hitoshi Yamamoto (Harvard University)
Inclusive CP Asymmetries in Semileptonic Decays of B Mesons
7 pages, 1 figure. Two references added, and a few typos corrected
Nucl.Phys.Proc.Suppl. 65 (1998) 236-239
10.1016/S0920-5632(97)01008-6
HUTP-97/A038
hep-ph
null
We estimate the sensitivity of single lepton CP violation measurements with respect to that of traditional di-lepton measurements. We find that the sensitivity of the single lepton method is better than that of the di-lepton method. The achievable sensitivity with the currently available data is already in the range relevant to standard model predictions. We also give general expressions for inclusive decay time distributions on $\Upsilon 4S$ where the other $B$ is not measured, which will be used to obtain time dependent asymmetries. The expression is of general use whenever one deals with inclusive time-dependent as well as time-integrated measurements in $\Upsilon(4S)\to B^0\bar B^0$ where the final state of the other $B$ is not reconstructed or when only the time difference is measured.
[ { "created": "Tue, 22 Jul 1997 15:10:34 GMT", "version": "v1" }, { "created": "Thu, 24 Jul 1997 16:33:13 GMT", "version": "v2" } ]
2009-10-30
[ [ "Yamamoto", "Hitoshi", "", "Harvard University" ] ]
We estimate the sensitivity of single lepton CP violation measurements with respect to that of traditional di-lepton measurements. We find that the sensitivity of the single lepton method is better than that of the di-lepton method. The achievable sensitivity with the currently available data is already in the range relevant to standard model predictions. We also give general expressions for inclusive decay time distributions on $\Upsilon 4S$ where the other $B$ is not measured, which will be used to obtain time dependent asymmetries. The expression is of general use whenever one deals with inclusive time-dependent as well as time-integrated measurements in $\Upsilon(4S)\to B^0\bar B^0$ where the final state of the other $B$ is not reconstructed or when only the time difference is measured.
hep-ph/0002147
Nicolao Fornengo
N. Fornengo (Valencia and Torino), M.C. Gonzalez-Garcia (Valencia) and J.W.F. Valle (Valencia)
Updated Global Analysis of the Atmospheric Neutrino Data in terms of neutrino oscillations
26 pages, 1 table, 8 figures, typeset with ReVTeX. In order to reduce size, the version on the archive has low resolution figures. A full version of the paper can be found at http://www.to.infn.it/~fornengo/papers/
Nucl.Phys.B580:58-82,2000
10.1016/S0550-3213(00)00213-3
FTUV/00-13, IFIC/00-14
hep-ph astro-ph hep-ex
null
A global analysis of all the available atmospheric neutrino data is presented in terms of neutrino oscillations in the nu_mu -> nu_tau and nu_mu -> nu_s channels, where nu_s denotes a sterile neutrino. We perform our analysis of the contained events data as well as the upward-going neutrino-induced muon fluxes. In addition to the previous data samples of Frejus, Nusex, IMB and Kamioka experiments, we include the full data set of the 52 kton-yr of Super-Kamiokande, the recent 4.6 kton-yr contained events of Soudan2 and the results on upgoing muons from the MACRO and Baksan detectors. From the statistical analysis it emerges that the nu_mu -> nu_tau channel provides the best agreement with the combined data, with a best fit point of sin^2(2 theta) = 0.99 and Delta m^2 = 3.0 * 10^{-3} eV^2. Although somehow disfavoured, the nu_mu -> nu_s channels cannot be ruled out on the basis of the global fit to the full set of observables.
[ { "created": "Mon, 14 Feb 2000 15:11:51 GMT", "version": "v1" } ]
2009-09-17
[ [ "Fornengo", "N.", "", "Valencia and Torino" ], [ "Gonzalez-Garcia", "M. C.", "", "Valencia" ], [ "Valle", "J. W. F.", "", "Valencia" ] ]
A global analysis of all the available atmospheric neutrino data is presented in terms of neutrino oscillations in the nu_mu -> nu_tau and nu_mu -> nu_s channels, where nu_s denotes a sterile neutrino. We perform our analysis of the contained events data as well as the upward-going neutrino-induced muon fluxes. In addition to the previous data samples of Frejus, Nusex, IMB and Kamioka experiments, we include the full data set of the 52 kton-yr of Super-Kamiokande, the recent 4.6 kton-yr contained events of Soudan2 and the results on upgoing muons from the MACRO and Baksan detectors. From the statistical analysis it emerges that the nu_mu -> nu_tau channel provides the best agreement with the combined data, with a best fit point of sin^2(2 theta) = 0.99 and Delta m^2 = 3.0 * 10^{-3} eV^2. Although somehow disfavoured, the nu_mu -> nu_s channels cannot be ruled out on the basis of the global fit to the full set of observables.
0807.3607
Wan-Il Park
Seongcheol Kim, Wan-Il Park and Ewan D. Stewart
Thermal inflation, baryogenesis and axions
53 pages, 20 figures. Figures reformatted, minor changes in Section 3, references added
JHEP 0901:015,2009
10.1088/1126-6708/2009/01/015
KAIST-TH 2008/05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a previous paper, we proposed a simple extension of the Minimal Supersymmetric Standard Model which gives rise to thermal inflation and baryogenesis in a natural and remarkably consistent way. In this paper, we consider the $\lambda_\phi = 0$ special case of our model, which is the minimal way to incorporate a Peccei-Quinn symmetry. The axino/flatino becomes the lightest supersymmetric particle with $m_\axino \sim 1$ to $10 \GeV$ and is typically over-produced during the flaton decay. Interestingly though, the dark matter abundance is minimized for $m_\axino \sim 1 \GeV$, $f_a \sim 10^{11}$ to $10^{12} \GeV$ and $|\mu| \sim 400 \GeV$ to $2 \TeV$ at an abundance coincident with the observed abundance and with significant amounts of both axions and axinos. Futhermore, for these values the baryon abundance naturally matches the observed abundance.
[ { "created": "Wed, 23 Jul 2008 06:28:02 GMT", "version": "v1" }, { "created": "Tue, 4 Nov 2008 14:52:13 GMT", "version": "v2" } ]
2009-02-12
[ [ "Kim", "Seongcheol", "" ], [ "Park", "Wan-Il", "" ], [ "Stewart", "Ewan D.", "" ] ]
In a previous paper, we proposed a simple extension of the Minimal Supersymmetric Standard Model which gives rise to thermal inflation and baryogenesis in a natural and remarkably consistent way. In this paper, we consider the $\lambda_\phi = 0$ special case of our model, which is the minimal way to incorporate a Peccei-Quinn symmetry. The axino/flatino becomes the lightest supersymmetric particle with $m_\axino \sim 1$ to $10 \GeV$ and is typically over-produced during the flaton decay. Interestingly though, the dark matter abundance is minimized for $m_\axino \sim 1 \GeV$, $f_a \sim 10^{11}$ to $10^{12} \GeV$ and $|\mu| \sim 400 \GeV$ to $2 \TeV$ at an abundance coincident with the observed abundance and with significant amounts of both axions and axinos. Futhermore, for these values the baryon abundance naturally matches the observed abundance.
1507.06204
Qing-Hong Cao
Qing-Hong Cao, Bin Yan
Determining $V_{tb}$ at Electron-Positron Colliders
publish version
Phys. Rev. D 92, 094018 (2015)
10.1103/PhysRevD.92.094018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Verifying $V_{tb} \simeq 1$ is critical to test the three generation assumption of the Standard Model. So far our best knowledge of $V_{tb}$ is inferred either from the $3\times 3$ unitarity of CKM matrix or from single top-quark productions upon the assumption of universal weak couplings. The unitarity could be relaxed in new physics models with extra heavy quarks and the universality of weak couplings could also be broken if the $Wtb$ coupling is modified in new physics models. In this work we propose to measure $V_{tb}$ in the process of $e^+ e^- \to t\bar{t}$ without prior knowledge of the number of fermion generations or the strength of the $Wtb$ coupling. Using an effective Lagrangian approach, we perform a model-independent analysis of the interactions among electroweak gauge bosons and the third generation quarks, i.e. the $Wtb$, $Zt\bar{t}$ and $Zb\bar{b}$ couplings. The electroweak symmetry of the Standard Model specifies a pattern of deviations of the $Z$-$t_L$-$t_L$ and $W$-$t_L$-$b_L$ couplings after one imposes the known experimental constraint on the $Z$-$b_L$-$b_L$ coupling. We demonstrate that, making use of the predicted pattern and the accurate measurements of top-quark mass and width from the energy threshold scan experiments, one can determine $V_{tb}$ from the cross section and the forward-backward asymmetry of top-quark pair production at an {\it unpolarized} electron-positron collider.
[ { "created": "Wed, 22 Jul 2015 14:24:40 GMT", "version": "v1" }, { "created": "Sat, 28 Nov 2015 03:22:23 GMT", "version": "v2" } ]
2015-12-01
[ [ "Cao", "Qing-Hong", "" ], [ "Yan", "Bin", "" ] ]
Verifying $V_{tb} \simeq 1$ is critical to test the three generation assumption of the Standard Model. So far our best knowledge of $V_{tb}$ is inferred either from the $3\times 3$ unitarity of CKM matrix or from single top-quark productions upon the assumption of universal weak couplings. The unitarity could be relaxed in new physics models with extra heavy quarks and the universality of weak couplings could also be broken if the $Wtb$ coupling is modified in new physics models. In this work we propose to measure $V_{tb}$ in the process of $e^+ e^- \to t\bar{t}$ without prior knowledge of the number of fermion generations or the strength of the $Wtb$ coupling. Using an effective Lagrangian approach, we perform a model-independent analysis of the interactions among electroweak gauge bosons and the third generation quarks, i.e. the $Wtb$, $Zt\bar{t}$ and $Zb\bar{b}$ couplings. The electroweak symmetry of the Standard Model specifies a pattern of deviations of the $Z$-$t_L$-$t_L$ and $W$-$t_L$-$b_L$ couplings after one imposes the known experimental constraint on the $Z$-$b_L$-$b_L$ coupling. We demonstrate that, making use of the predicted pattern and the accurate measurements of top-quark mass and width from the energy threshold scan experiments, one can determine $V_{tb}$ from the cross section and the forward-backward asymmetry of top-quark pair production at an {\it unpolarized} electron-positron collider.
2008.01086
Teppei Kitahara
Syuhei Iguro, Teppei Kitahara
Implications for new physics from a novel puzzle in $\bar{B}_{(s)}^0 \to D^{(\ast)+}_{(s)} \lbrace \pi^-, K^- \rbrace$ decays
9 pages, 1 figure; v2: references added; v3: version published as a Rapid Communication in PRD
Phys. Rev. D 102, 071701 (2020)
10.1103/PhysRevD.102.071701
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Recently, the standard model predictions for the $B$-meson hadronic decays, $\bar{B}^0 \to D^{(\ast)+}K^-$ and $\bar{B}^0_s \to D^{(\ast)+}_s \pi^-$, have been updated based on the QCD factorization approach. This improvement sheds light on a novel puzzle in the $B$-meson hadronic decays: there are mild but universal tensions between data and the predicted branching ratios. Assuming the higher-order QCD corrections are not huge enough to solve the tension, we examine several new physics interpretations of this puzzle. We find that the tension can be partially explained by a left-handed $W^\prime$ model, which can be compatible with other flavor observables and collider bounds.
[ { "created": "Mon, 3 Aug 2020 18:00:01 GMT", "version": "v1" }, { "created": "Sat, 15 Aug 2020 08:25:15 GMT", "version": "v2" }, { "created": "Thu, 8 Oct 2020 03:17:07 GMT", "version": "v3" } ]
2020-11-11
[ [ "Iguro", "Syuhei", "" ], [ "Kitahara", "Teppei", "" ] ]
Recently, the standard model predictions for the $B$-meson hadronic decays, $\bar{B}^0 \to D^{(\ast)+}K^-$ and $\bar{B}^0_s \to D^{(\ast)+}_s \pi^-$, have been updated based on the QCD factorization approach. This improvement sheds light on a novel puzzle in the $B$-meson hadronic decays: there are mild but universal tensions between data and the predicted branching ratios. Assuming the higher-order QCD corrections are not huge enough to solve the tension, we examine several new physics interpretations of this puzzle. We find that the tension can be partially explained by a left-handed $W^\prime$ model, which can be compatible with other flavor observables and collider bounds.
hep-ph/0106166
Arthur Hebecker
A. Hebecker, J. March-Russell
A Minimal S^1/(Z_2 x Z_2') Orbifold GUT
13 pages. References corrected
Nucl.Phys.B613:3-16,2001
10.1016/S0550-3213(01)00374-1
CERN-TH/2001-156, LBNL-48220
hep-ph hep-th
null
We investigate supersymmetric SU(5) grand-unified theories (GUTs) realized in 5 space-time dimensions and broken down to the MSSM by SU(5)-violating boundary conditions on a S^1/(Z_2 x Z_2') orbifold with two 3-branes. The doublet-triplet splitting problem is entirely avoided by locating the MSSM Higgs doublets on the brane on which SU(5) is not a good symmetry. An extremely simple model is then described in which the MSSM matter is also located on this SU(5)-violating brane. Although this model does not unify the MSSM matter within SU(5) multiplets, it explains gauge coupling unification. A second model with MSSM matter in the SU(5)-symmetric bulk preserves both the SU(5) explanation of fermion quantum numbers as well as gauge-coupling unification. Both models naturally avoid problematic SU(5) predictions for the Yukawa couplings of the first two generations and are consistent with proton decay constraints. We analyse the running of gauge couplings above the compactification scale in terms of a 5d effective action and derive the implications for the values of compactification scale, unification scale and of the scale at which the bulk gauge theory becomes strongly coupled.
[ { "created": "Fri, 15 Jun 2001 19:58:34 GMT", "version": "v1" }, { "created": "Tue, 19 Jun 2001 22:05:03 GMT", "version": "v2" }, { "created": "Tue, 24 Jul 2001 09:27:55 GMT", "version": "v3" } ]
2014-11-17
[ [ "Hebecker", "A.", "" ], [ "March-Russell", "J.", "" ] ]
We investigate supersymmetric SU(5) grand-unified theories (GUTs) realized in 5 space-time dimensions and broken down to the MSSM by SU(5)-violating boundary conditions on a S^1/(Z_2 x Z_2') orbifold with two 3-branes. The doublet-triplet splitting problem is entirely avoided by locating the MSSM Higgs doublets on the brane on which SU(5) is not a good symmetry. An extremely simple model is then described in which the MSSM matter is also located on this SU(5)-violating brane. Although this model does not unify the MSSM matter within SU(5) multiplets, it explains gauge coupling unification. A second model with MSSM matter in the SU(5)-symmetric bulk preserves both the SU(5) explanation of fermion quantum numbers as well as gauge-coupling unification. Both models naturally avoid problematic SU(5) predictions for the Yukawa couplings of the first two generations and are consistent with proton decay constraints. We analyse the running of gauge couplings above the compactification scale in terms of a 5d effective action and derive the implications for the values of compactification scale, unification scale and of the scale at which the bulk gauge theory becomes strongly coupled.
hep-ph/0101223
Huitzu Tu
V. A. Bednyakov, H. V. Klapdor-Kleingrothaus, H. Tu
Higgs Bosons and the Indirect Search for WIMPs
10 pages, 4 figures. Talk given at Dark2000, Heidelberg, Germany, 10-15 July, 2000
Phys.Rev. D64 (2001) 075004
10.1103/PhysRevD.64.075004
null
hep-ph
null
We investigated the contribution of the MSSM Higgs bosons produced in the neutralino annihilation in the Earth and Sun to the total WIMPs detection signals. We found that this contribution is very important and results in a lower bound for the muon flux from the Sun of 10^{-7} - 10^{-8} m^{-2} yr^{-1} for neutralinos heavier than 200 GeV. We noticed that due to the SUSY charged Higgs bosons one can expect an energetic tau neutrino flux from the Sun at a level of 10^2 m^{-2} yr^{-1}.
[ { "created": "Fri, 19 Jan 2001 18:33:15 GMT", "version": "v1" } ]
2009-11-07
[ [ "Bednyakov", "V. A.", "" ], [ "Klapdor-Kleingrothaus", "H. V.", "" ], [ "Tu", "H.", "" ] ]
We investigated the contribution of the MSSM Higgs bosons produced in the neutralino annihilation in the Earth and Sun to the total WIMPs detection signals. We found that this contribution is very important and results in a lower bound for the muon flux from the Sun of 10^{-7} - 10^{-8} m^{-2} yr^{-1} for neutralinos heavier than 200 GeV. We noticed that due to the SUSY charged Higgs bosons one can expect an energetic tau neutrino flux from the Sun at a level of 10^2 m^{-2} yr^{-1}.
hep-ph/9211330
null
Pankaj Jain and Herman J. Munczek
q\bar q$ Bound States in the Bethe-Salpeter Formalism
4 pages 1 figure (not included, available upon request), report # KUHEP-20
null
null
null
hep-ph
null
We solve the Bethe-Salpeter equation in order to determine the spectrum of pseudoscalar and vector meson bound states for light as well as heavy quarks. The fermion propagators are obtained by solving the Schwinger-Dyson equation consistently with the Bethe-Salpeter equation, a procedure necessary for demonstrating the Goldstone nature of the pion in the chiral limit. Our results agree qualitatively and quantitatively with expectations both from current algebra for light quarks and from composite models for heavy quarks.}
[ { "created": "Sun, 29 Nov 1992 16:54:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jain", "Pankaj", "" ], [ "Munczek", "Herman J.", "" ] ]
We solve the Bethe-Salpeter equation in order to determine the spectrum of pseudoscalar and vector meson bound states for light as well as heavy quarks. The fermion propagators are obtained by solving the Schwinger-Dyson equation consistently with the Bethe-Salpeter equation, a procedure necessary for demonstrating the Goldstone nature of the pion in the chiral limit. Our results agree qualitatively and quantitatively with expectations both from current algebra for light quarks and from composite models for heavy quarks.}
0805.0994
Alexander E. Dorokhov
A.E. Dorokhov
Recent results on rare decay pi0 to e+e-
5 pages, 3 figures, talk at Int. Workshop on e+e- collisions from Phi to Psi, 7-10 April 2008, Frascati, Italy
Nucl.Phys.Proc.Suppl.181-182:37-41,2008
10.1016/j.nuclphysbps.2008.09.018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experimental and theoretical progress concerning the rare decay pi0 to e+e- is briefly reviewed. It includes the latest data from KTeV and a new model independent estimate of the decay branching which show the deviation between experiment and theory at the level of 3.3\sigma.
[ { "created": "Wed, 7 May 2008 14:32:23 GMT", "version": "v1" } ]
2008-11-07
[ [ "Dorokhov", "A. E.", "" ] ]
Experimental and theoretical progress concerning the rare decay pi0 to e+e- is briefly reviewed. It includes the latest data from KTeV and a new model independent estimate of the decay branching which show the deviation between experiment and theory at the level of 3.3\sigma.
1307.3152
Andrey Grabovsky
A.V. Grabovsky
On the solution to the NLO forward BFKL equation
6 pages
null
10.1007/JHEP09(2013)098
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is demonstrated that the NLO forward BFKL equation can be solved in the space of its Born eigenfunctions.
[ { "created": "Thu, 11 Jul 2013 15:55:21 GMT", "version": "v1" } ]
2015-06-16
[ [ "Grabovsky", "A. V.", "" ] ]
It is demonstrated that the NLO forward BFKL equation can be solved in the space of its Born eigenfunctions.
1012.4398
Christopher Smith
Christopher Smith
Rare K and B decays with non-standard missing energy
Talk given at CKM2010, 6th International Workshop on the CKM Unitarity Triangle, University of Warwick, UK, 6-10 September 2010
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The rare K and B semileptonic decays into neutrino pairs are well-known to be extremely sensitive to non-standard physics in the quark sector. In this talk, their capabilities to signal New Physics in the leptonic sector, or even to reveal entirely new invisible sectors, are analyzed.
[ { "created": "Mon, 20 Dec 2010 16:49:18 GMT", "version": "v1" } ]
2010-12-21
[ [ "Smith", "Christopher", "" ] ]
The rare K and B semileptonic decays into neutrino pairs are well-known to be extremely sensitive to non-standard physics in the quark sector. In this talk, their capabilities to signal New Physics in the leptonic sector, or even to reveal entirely new invisible sectors, are analyzed.
2203.03700
Howard Baer
Howard Baer, Vernon Barger, Dibyashree Sengupta and Xerxes Tata
Angular cuts to reduce the tautaubar+jet background to the higgsino signal at the LHC
17 pages plus 13 .png figures; contribution to Snowmass 2021
null
null
UH-511-1324-22
hep-ph
http://creativecommons.org/licenses/by/4.0/
We re-examine higgsino pair production in association with a hard QCD jet at the LHC. We focus on \ell^+\ell^- +MET +jet events from the production and subsequent decay, \tchi_2^0\to\tchi_1^0\ell^+\ell^-, of the heavier neutral higgsino. The novel feature of our analysis is that we propose angular cuts to reduce the irreducible background from Z(-> \tau\bar{\tau})+jet events more efficiently than the m_{\tau\tau}^2<0 cut that has been used by the ATLAS and CMS collaborations. Additional cuts, needed to reduce backgrounds from t\bar{t}, WWj and W/Z+\ell\bar{\ell} production, are also delineated. We evaluate the reach of LHC14 for 300 and 3000~fb^{-1} and stress that the dilepton mass distribution would serve to characterize the higgsino signal.
[ { "created": "Mon, 7 Mar 2022 20:58:48 GMT", "version": "v1" } ]
2022-03-09
[ [ "Baer", "Howard", "" ], [ "Barger", "Vernon", "" ], [ "Sengupta", "Dibyashree", "" ], [ "Tata", "Xerxes", "" ] ]
We re-examine higgsino pair production in association with a hard QCD jet at the LHC. We focus on \ell^+\ell^- +MET +jet events from the production and subsequent decay, \tchi_2^0\to\tchi_1^0\ell^+\ell^-, of the heavier neutral higgsino. The novel feature of our analysis is that we propose angular cuts to reduce the irreducible background from Z(-> \tau\bar{\tau})+jet events more efficiently than the m_{\tau\tau}^2<0 cut that has been used by the ATLAS and CMS collaborations. Additional cuts, needed to reduce backgrounds from t\bar{t}, WWj and W/Z+\ell\bar{\ell} production, are also delineated. We evaluate the reach of LHC14 for 300 and 3000~fb^{-1} and stress that the dilepton mass distribution would serve to characterize the higgsino signal.
hep-ph/9708342
Zoltan Trocsanyi
Zoltan Nagy and Zoltan Trocsanyi
Group independent color decomposition of next-to-leading order matrix elements for e^+ e^- \to four partons
11 pages, elsart style
Phys.Lett. B414 (1997) 187-194
10.1016/S0370-2693(97)01161-1
null
hep-ph
null
We present the next-to-leading order partonic cross sections involving an electroweak vector boson and four massless partons (quarks, gluons or long living gluinos) in a general gauge theory with a simple Lie Group. The vector boson couples to a massless lepton pair and a quark-antiquark pair. The cross sections are given in terms of group independent kinematical functions multiplying the eigenvalues of the Casimir operators of the Lie group. This kind of color decomposition is required for the calculation of O($\alpha_s^3$) corrections to the group independent kinematical functions in the four-jet production cross sections in electron-positron annihilation. The knowledge of these corrections facilitates the simultaneous precision meaurement of the strong coupling and the color charge factors using the four-jet LEP or SLC data as well as the test whether these data favour or exclude the existence of a light gluino.
[ { "created": "Wed, 13 Aug 1997 17:49:02 GMT", "version": "v1" } ]
2009-10-30
[ [ "Nagy", "Zoltan", "" ], [ "Trocsanyi", "Zoltan", "" ] ]
We present the next-to-leading order partonic cross sections involving an electroweak vector boson and four massless partons (quarks, gluons or long living gluinos) in a general gauge theory with a simple Lie Group. The vector boson couples to a massless lepton pair and a quark-antiquark pair. The cross sections are given in terms of group independent kinematical functions multiplying the eigenvalues of the Casimir operators of the Lie group. This kind of color decomposition is required for the calculation of O($\alpha_s^3$) corrections to the group independent kinematical functions in the four-jet production cross sections in electron-positron annihilation. The knowledge of these corrections facilitates the simultaneous precision meaurement of the strong coupling and the color charge factors using the four-jet LEP or SLC data as well as the test whether these data favour or exclude the existence of a light gluino.
hep-ph/0406285
Nick Evans
Nick Evans and Phil Membry
Higgsless W Unitarity from Decoupling Deconstruction
10 pages, 6 figures, additional discussion
null
null
SHEP-04-19
hep-ph
null
Recently there has been interest in electroweak models on a five dimensional interval that break the symmetry without a higgs boson. By warping the metric of the interval it may be possible to avoid experimental bounds on extra W bosons and delta rho. Five dimensional models necessarily require an explicit UV cut-off to remain perturbative, such as that provided by deconstruction. We study a simple deconstruction of this scenario with a chain of SU(2)^N+1 x U(1)_Y groups linked by bi-fundamental higgs. There are two interesting decoupling limits of this model, when the higgs vevs are taken large and when the SU(2) couplings grow, which might provide a perturbative realization. In fact it is very challenging to satisfy all the experimental bounds and the most compatible scenario has both a higgs and a relatively strongly coupled new W both close to 2 TeV
[ { "created": "Fri, 25 Jun 2004 09:33:22 GMT", "version": "v1" }, { "created": "Wed, 11 Aug 2004 09:15:39 GMT", "version": "v2" } ]
2007-05-23
[ [ "Evans", "Nick", "" ], [ "Membry", "Phil", "" ] ]
Recently there has been interest in electroweak models on a five dimensional interval that break the symmetry without a higgs boson. By warping the metric of the interval it may be possible to avoid experimental bounds on extra W bosons and delta rho. Five dimensional models necessarily require an explicit UV cut-off to remain perturbative, such as that provided by deconstruction. We study a simple deconstruction of this scenario with a chain of SU(2)^N+1 x U(1)_Y groups linked by bi-fundamental higgs. There are two interesting decoupling limits of this model, when the higgs vevs are taken large and when the SU(2) couplings grow, which might provide a perturbative realization. In fact it is very challenging to satisfy all the experimental bounds and the most compatible scenario has both a higgs and a relatively strongly coupled new W both close to 2 TeV
hep-ph/9411260
Timo van Ritbergen
S. A. Larin, T. van Ritbergen, J. A. M. Vermaseren
The Large Quark Mass Expansion of Gamma (Z^0 -> hadrons) and Gamma(tau^- -> nu_tau + hadrons) in the Order alpha_s^3
Postscript generation repaired, The complete postscript file of this article, including figures, is now available at ftp://nikhefh.nikhef.nl/pub/preprints/H94-30.ps.gz
Nucl.Phys. B438 (1995) 278-306
10.1016/0550-3213(94)00574-X
null
hep-ph
null
We present the analytical $\alpha_{s}^3$ correction to the $Z^{0}$ decay rate into hadrons. We calculate this correction up to (and including) terms of the order $(m_Z^2/m_{top}^2)^3$ in the large top quark mass expansion. We rely on the technique of the large mass expansion of individual Feynman diagrams and treat its application in detail. We convert the obtained results of six flavour QCD to the results in the effective theory with five active flavours, checking the decoupling relation of the QCD coupling constant. We also derive the large charm quark mass expansion of the semihadronic $\tau$ lepton decay rate in the $\alpha_{s}^3$ approximation.
[ { "created": "Thu, 10 Nov 1994 11:59:49 GMT", "version": "v1" }, { "created": "Mon, 17 Mar 1997 18:21:57 GMT", "version": "v2" } ]
2009-10-28
[ [ "Larin", "S. A.", "" ], [ "van Ritbergen", "T.", "" ], [ "Vermaseren", "J. A. M.", "" ] ]
We present the analytical $\alpha_{s}^3$ correction to the $Z^{0}$ decay rate into hadrons. We calculate this correction up to (and including) terms of the order $(m_Z^2/m_{top}^2)^3$ in the large top quark mass expansion. We rely on the technique of the large mass expansion of individual Feynman diagrams and treat its application in detail. We convert the obtained results of six flavour QCD to the results in the effective theory with five active flavours, checking the decoupling relation of the QCD coupling constant. We also derive the large charm quark mass expansion of the semihadronic $\tau$ lepton decay rate in the $\alpha_{s}^3$ approximation.
1206.3760
Diptimoy Ghosh
Alakabha Datta, Murugeswaran Duraisamy, Diptimoy Ghosh
Diagnosing New Physics in $b \to c \, \tau \, \nu_\tau$ decays in the light of the recent BaBar result
Some typos corrected (not updated in journal)
PhysRevD.86.034027(2012)
10.1103/PhysRevD.86.034027
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The BaBar Collaboration has recently reported the measurement of the ratio of the branching fractions of $\bar{B} \to D(D^{*}) \tau^{-} \bar{\nu_\tau}$ to $\bar{B} \to D(D^{*}) \ell^{-} \bar{\nu_\ell}$ which deviates from the Standard Model prediction by 2$\sigma$(2.7$\sigma$). This deviation goes up to 3.4$\sigma$ level when the two measurements in the $D$ and $D^*$ modes are taken together and could indicate new physics. Using an effective Lagrangian for the new physics we study the implication of these results and calculate other observables that can shed light on the nature of the new physics. We show that the measurements of the forward-backward asymmetries and the $\tau$ and $D^*$ polarization fractions can distinguish among the various couplings of the new physics operators.
[ { "created": "Sun, 17 Jun 2012 15:12:39 GMT", "version": "v1" }, { "created": "Sun, 22 Jul 2012 15:48:18 GMT", "version": "v2" }, { "created": "Mon, 22 Oct 2012 06:53:00 GMT", "version": "v3" }, { "created": "Mon, 12 Mar 2018 16:48:54 GMT", "version": "v4" } ]
2018-03-13
[ [ "Datta", "Alakabha", "" ], [ "Duraisamy", "Murugeswaran", "" ], [ "Ghosh", "Diptimoy", "" ] ]
The BaBar Collaboration has recently reported the measurement of the ratio of the branching fractions of $\bar{B} \to D(D^{*}) \tau^{-} \bar{\nu_\tau}$ to $\bar{B} \to D(D^{*}) \ell^{-} \bar{\nu_\ell}$ which deviates from the Standard Model prediction by 2$\sigma$(2.7$\sigma$). This deviation goes up to 3.4$\sigma$ level when the two measurements in the $D$ and $D^*$ modes are taken together and could indicate new physics. Using an effective Lagrangian for the new physics we study the implication of these results and calculate other observables that can shed light on the nature of the new physics. We show that the measurements of the forward-backward asymmetries and the $\tau$ and $D^*$ polarization fractions can distinguish among the various couplings of the new physics operators.
hep-ph/9504407
Wolfgang Ratzka
G. Piller, W. Ratzka, and W. Weise
Phenomenology of Nuclear Shadowing in Deep-Inelastic Scattering
26 pages, LaTeX, 16 PostScript figures available from http://www.physik.uni-regensburg.de/~c4080/prw/
Z.Phys. A352 (1995) 427-439
10.1007/BF01299761
ADP-95-10/T173, TUM/T39-95-1
hep-ph
null
We investigate shadowing effects in deep-inelastic scattering from nuclei at small values $x<0.1$ of the Bjorken variable. Unifying aspects of generalized vector meson dominance and color transparency we first develop a model for deep-inelastic scattering from free nucleons at small $x$. In application to nuclear targets we find that the coherent interaction of quark-antiquark fluctuations with nucleons in a nucleus leads to the observed shadowing at $x<0.1$. We compare our results with most of the recent data for a large variety of nuclei and examine in particular the $Q^2$ dependence of the shadowing effect. While the coherent interaction of low mass vector mesons causes a major part of the shadowing observed in the $Q^2$ range of current experiments, the coherent scattering of continuum quark-antiquark pairs is also important and guarantees a very weak overall $Q^2$ dependence of the effect. We also discuss shadowing in deuterium and its implications for the quark flavor structure of nucleons. Finally we comment on shadowing effects in high-energy photon-nucleus reactions with real photons.
[ { "created": "Thu, 27 Apr 1995 12:44:04 GMT", "version": "v1" }, { "created": "Thu, 27 Apr 1995 13:32:02 GMT", "version": "v2" } ]
2015-06-25
[ [ "Piller", "G.", "" ], [ "Ratzka", "W.", "" ], [ "Weise", "W.", "" ] ]
We investigate shadowing effects in deep-inelastic scattering from nuclei at small values $x<0.1$ of the Bjorken variable. Unifying aspects of generalized vector meson dominance and color transparency we first develop a model for deep-inelastic scattering from free nucleons at small $x$. In application to nuclear targets we find that the coherent interaction of quark-antiquark fluctuations with nucleons in a nucleus leads to the observed shadowing at $x<0.1$. We compare our results with most of the recent data for a large variety of nuclei and examine in particular the $Q^2$ dependence of the shadowing effect. While the coherent interaction of low mass vector mesons causes a major part of the shadowing observed in the $Q^2$ range of current experiments, the coherent scattering of continuum quark-antiquark pairs is also important and guarantees a very weak overall $Q^2$ dependence of the effect. We also discuss shadowing in deuterium and its implications for the quark flavor structure of nucleons. Finally we comment on shadowing effects in high-energy photon-nucleus reactions with real photons.
0904.1580
Ernest Ma
Ernest Ma (UC Riverside)
Deciphering the Seesaw Nature of Neutrino Mass from Unitarity Violation
7 pages, no figure, linear and lopsided seesaws discussed
Mod.Phys.Lett.A24:2161-2165,2009
10.1142/S0217732309031776
UCRHEP-T465 (April 2009)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If neutrino masses are obtained via the canonical seesaw mechanism, based on an underlying 2X2 mass matrix, unitarity violation of the neutrino mixing matrix is unavoidable, but its effect is extremely small. On the other hand, in the inverse (and linear) seesaw mechanisms, based on an underlying 3X3 mass matrix, it can be significant and possibly observable. This 3X3 matrix is examined in more detail, and a NEW variation (the lopsided seesaw) is proposed which has features of both mechanisms. A concrete example based on U(1)_N is discussed.
[ { "created": "Thu, 9 Apr 2009 18:31:20 GMT", "version": "v1" }, { "created": "Sun, 19 Apr 2009 15:31:16 GMT", "version": "v2" }, { "created": "Mon, 18 May 2009 20:13:02 GMT", "version": "v3" }, { "created": "Sun, 24 May 2009 17:29:38 GMT", "version": "v4" } ]
2010-11-15
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
If neutrino masses are obtained via the canonical seesaw mechanism, based on an underlying 2X2 mass matrix, unitarity violation of the neutrino mixing matrix is unavoidable, but its effect is extremely small. On the other hand, in the inverse (and linear) seesaw mechanisms, based on an underlying 3X3 mass matrix, it can be significant and possibly observable. This 3X3 matrix is examined in more detail, and a NEW variation (the lopsided seesaw) is proposed which has features of both mechanisms. A concrete example based on U(1)_N is discussed.
2201.05934
Gabriele Inghirami
Gabriele Inghirami and Hannah Elfner
The applicability of hydrodynamics in heavy ion collisions at $\sqrt{s_{\rm NN}}$= 2.4-7.7 GeV
Ancillary files with plots data and workflow provided. Version 2 corresponding to version accepted for publication by EPJC
null
10.1140/epjc/s10052-022-10718-x
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
To assess the degree of equilibration of the matter created in heavy-ion reactions at low to intermediate beam energies, a hadronic transport approach (SMASH) is employed. By using a coarse-graining method, we compute the energy momentum tensor of the system at fixed time steps and evaluate the degree of isotropy of the diagonal terms and the relative magnitude of the off-diagonal terms. This study focuses mostly on Au+Au collisions in the energy range $\sqrt{s_{\rm NN}}$ = 2.4-7.7 GeV, but central collisions of lighter ions like C+C, Ar+KCl and Ag+Ag are considered as well. We find that the conditions concerning local equilibration for a hydrodynamic description are reasonably satisfied in a large portion of the system for a significant amount of time (several fm/c) when considering the average evolution of many events, yet they are rarely fulfilled on an event by event basis. This is relevant for the application of hybrid approaches at low beam energies as they are or will be reached by the HADES experiment at GSI, the future CBM experiment at FAIR as well as the beam energy scan program at RHIC.
[ { "created": "Sat, 15 Jan 2022 23:39:59 GMT", "version": "v1" }, { "created": "Thu, 8 Sep 2022 21:41:41 GMT", "version": "v2" } ]
2022-09-12
[ [ "Inghirami", "Gabriele", "" ], [ "Elfner", "Hannah", "" ] ]
To assess the degree of equilibration of the matter created in heavy-ion reactions at low to intermediate beam energies, a hadronic transport approach (SMASH) is employed. By using a coarse-graining method, we compute the energy momentum tensor of the system at fixed time steps and evaluate the degree of isotropy of the diagonal terms and the relative magnitude of the off-diagonal terms. This study focuses mostly on Au+Au collisions in the energy range $\sqrt{s_{\rm NN}}$ = 2.4-7.7 GeV, but central collisions of lighter ions like C+C, Ar+KCl and Ag+Ag are considered as well. We find that the conditions concerning local equilibration for a hydrodynamic description are reasonably satisfied in a large portion of the system for a significant amount of time (several fm/c) when considering the average evolution of many events, yet they are rarely fulfilled on an event by event basis. This is relevant for the application of hybrid approaches at low beam energies as they are or will be reached by the HADES experiment at GSI, the future CBM experiment at FAIR as well as the beam energy scan program at RHIC.
1906.02512
Ilkka Helenius
Kari J. Eskola, Ilkka Helenius, Petja Paakkinen and Hannu Paukkunen
A QCD analysis of LHCb D-meson data in p+Pb collisions
29 pages, 13 figures. v2: version accepted for publication in JHEP
null
10.1007/JHEP05(2020)037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We scrutinize the recent LHCb data for D$^0$-meson production in p+Pb collisions within a next-to-leading order QCD framework. Our calculations are performed in the SACOT-$m_{\rm T}$ variant of the general-mass variable-flavour-number scheme (GM-VFNS), which has previously been shown to provide a realistic description of the LHC p+p data. Using the EPPS16 and nCTEQ15 nuclear parton distribution functions (PDFs) we show that a very good agreement is obtained also in the p+Pb case both for cross sections and nuclear modification ratios in the wide rapidity range covered by the LHCb data. Encouraged by the good correspondence, we quantify the impact of these data on the nuclear PDFs by the Hessian reweighting technique. We find compelling direct evidence of gluon shadowing at small momentum fractions $x$, with no signs of parton dynamics beyond the collinear factorization. We also compare our theoretical framework to a fixed-order calculation supplemented with a parton shower. While the two frameworks differ in the absolute cross sections, these differences largely cancel in the nuclear modification ratios. Thus, the constraints for nuclear PDFs appear solid.
[ { "created": "Thu, 6 Jun 2019 10:46:38 GMT", "version": "v1" }, { "created": "Thu, 7 May 2020 12:20:39 GMT", "version": "v2" } ]
2020-06-24
[ [ "Eskola", "Kari J.", "" ], [ "Helenius", "Ilkka", "" ], [ "Paakkinen", "Petja", "" ], [ "Paukkunen", "Hannu", "" ] ]
We scrutinize the recent LHCb data for D$^0$-meson production in p+Pb collisions within a next-to-leading order QCD framework. Our calculations are performed in the SACOT-$m_{\rm T}$ variant of the general-mass variable-flavour-number scheme (GM-VFNS), which has previously been shown to provide a realistic description of the LHC p+p data. Using the EPPS16 and nCTEQ15 nuclear parton distribution functions (PDFs) we show that a very good agreement is obtained also in the p+Pb case both for cross sections and nuclear modification ratios in the wide rapidity range covered by the LHCb data. Encouraged by the good correspondence, we quantify the impact of these data on the nuclear PDFs by the Hessian reweighting technique. We find compelling direct evidence of gluon shadowing at small momentum fractions $x$, with no signs of parton dynamics beyond the collinear factorization. We also compare our theoretical framework to a fixed-order calculation supplemented with a parton shower. While the two frameworks differ in the absolute cross sections, these differences largely cancel in the nuclear modification ratios. Thus, the constraints for nuclear PDFs appear solid.
hep-ph/9309319
Michael Dine
Michael Dine
Topics in String Phenomenology
20 pages, SCIPP 93/20
null
null
null
hep-ph
null
We consider two questions in string ``phenomenology.'' First, are there any generic string predictions? Second, are there any general lessons which string theory suggests for thinking about low energy models, particularly in the framework of supersymmetry? Among the topics we consider are the squark and slepton spectrum, flavor symmetries, discrete symmetries including $CP$, and Peccei-Quinn symmetries. We also note that in some cases, discrete symmetries can be used to constrain the form of supersymmetry breaking.
[ { "created": "Thu, 23 Sep 1993 21:09:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dine", "Michael", "" ] ]
We consider two questions in string ``phenomenology.'' First, are there any generic string predictions? Second, are there any general lessons which string theory suggests for thinking about low energy models, particularly in the framework of supersymmetry? Among the topics we consider are the squark and slepton spectrum, flavor symmetries, discrete symmetries including $CP$, and Peccei-Quinn symmetries. We also note that in some cases, discrete symmetries can be used to constrain the form of supersymmetry breaking.
hep-ph/9504309
Nonaka Toshihiko
Masayuki Koike, Toshihiko Nonaka and Tadashi Kon
Polarization Effects in Chargino Production at High Energy $\gamma\gamma$ Colliders
7 pages, latex , 3 figures are available upon request
Phys.Lett. B357 (1995) 232-236
10.1016/0370-2693(95)00759-E
RUP-5-95 ,ITP-SU-95/01
hep-ph
null
We investigate the chargino production process $\gamma\gamma\rightarrow\tilde{W}^{+}\tilde{W}^{-}$ at high energy $\gamma\gamma$ colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy $\gamma$ beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV $ee$ colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section and for us to extract the signal from the dominant background $\gamma\gamma\rightarrow{W}^{+}{W}^{-}$.
[ { "created": "Sat, 15 Apr 1995 06:40:32 GMT", "version": "v1" } ]
2019-08-15
[ [ "Koike", "Masayuki", "" ], [ "Nonaka", "Toshihiko", "" ], [ "Kon", "Tadashi", "" ] ]
We investigate the chargino production process $\gamma\gamma\rightarrow\tilde{W}^{+}\tilde{W}^{-}$ at high energy $\gamma\gamma$ colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy $\gamma$ beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV $ee$ colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section and for us to extract the signal from the dominant background $\gamma\gamma\rightarrow{W}^{+}{W}^{-}$.
1012.2485
Sandro Palestini
Sandro Palestini (CERN)
Angular distribution and rotations of frame in vector meson decays into lepton pairs
7 pages, 3 figures
Phys.Rev.D83:031503,2011
10.1103/PhysRevD.83.031503
CERN-PH-EP-2010-080
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss how the angular distribution of lepton pairs from decays of vector mesons depends on the choice of reference frame, and provide a geometrical description of the transformations of the coefficients of the angular distribution. Invariant expressions involving all coefficients are discussed, together with bounds and consistency relations.
[ { "created": "Sat, 11 Dec 2010 20:07:24 GMT", "version": "v1" } ]
2011-02-18
[ [ "Palestini", "Sandro", "", "CERN" ] ]
We discuss how the angular distribution of lepton pairs from decays of vector mesons depends on the choice of reference frame, and provide a geometrical description of the transformations of the coefficients of the angular distribution. Invariant expressions involving all coefficients are discussed, together with bounds and consistency relations.
1410.3984
Rafael L. Delgado
Rafael L. Delgado, Antonio Dobado and Felipe J. Llanes-Estrada
Strongly interacting $W_L W_L, Z_L Z_L$ and $hh$ from unitarized one-loop computations
3 pages, 3 figures, ICHEP2014 Proceedings
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, a new boson h has been discovered at the LHC which, so far, is compatible with the properties of the SM Higgs. However, the SM is not the most general low-energy dynamics for the minimal electroweak symmetry breaking sector with three Goldstone bosons and one light scalar. By using non-linear effective Lagrangian for these four particles we study different processes at one-loop precision, identifying the counterterms needed to cancel the divergences. Then we apply the IAM unitarization method on the partial waves, both to make more realistic predictions which could be tested at the LHC and to discuss the limitations of the one-loop computations. The studied processes are the elastic scattering amplitude for both the longitudinal components of the gauge bosons V = W, Z and the hh -> hh, as well as the inelastic VV -> hh.
[ { "created": "Wed, 15 Oct 2014 09:22:31 GMT", "version": "v1" } ]
2014-10-16
[ [ "Delgado", "Rafael L.", "" ], [ "Dobado", "Antonio", "" ], [ "Llanes-Estrada", "Felipe J.", "" ] ]
Recently, a new boson h has been discovered at the LHC which, so far, is compatible with the properties of the SM Higgs. However, the SM is not the most general low-energy dynamics for the minimal electroweak symmetry breaking sector with three Goldstone bosons and one light scalar. By using non-linear effective Lagrangian for these four particles we study different processes at one-loop precision, identifying the counterterms needed to cancel the divergences. Then we apply the IAM unitarization method on the partial waves, both to make more realistic predictions which could be tested at the LHC and to discuss the limitations of the one-loop computations. The studied processes are the elastic scattering amplitude for both the longitudinal components of the gauge bosons V = W, Z and the hh -> hh, as well as the inelastic VV -> hh.
2312.13723
Benjamin Roberts
Melina Filzinger, Ashlee R. Caddell, Dhruv Jani, Martin Steinel, Leonardo Giani, Nils Huntemann, Benjamin M. Roberts
Ultralight Dark Matter Search with Space-Time Separated Atomic Clocks and Cavities
7 pages, 2 figures
null
null
null
hep-ph astro-ph.CO physics.atom-ph
http://creativecommons.org/licenses/by/4.0/
We devise and demonstrate a method to search for non-gravitational couplings of ultralight dark matter to standard model particles using space-time separated atomic clocks and cavity-stabilized lasers. By making use of space-time separated sensors, which probe different values of an oscillating dark matter field, we can search for couplings that cancel in typical local experiments. We demonstrate this method using existing data from a frequency comparison of lasers stabilized to two optical cavities connected via a 2220 km fiber link [Nat. Commun. 13, 212 (2022)]. The absence of significant oscillations in the data results in constraints on the coupling of scalar dark matter to electrons, d_me, for masses between 1e-19 eV and 2e-15 eV. These are the first constraints on d_me alone in this mass range, and improve the dark matter constraints on any scalar-Fermion coupling by up to two orders of magnitude.
[ { "created": "Thu, 21 Dec 2023 10:40:35 GMT", "version": "v1" } ]
2023-12-22
[ [ "Filzinger", "Melina", "" ], [ "Caddell", "Ashlee R.", "" ], [ "Jani", "Dhruv", "" ], [ "Steinel", "Martin", "" ], [ "Giani", "Leonardo", "" ], [ "Huntemann", "Nils", "" ], [ "Roberts", "Benjamin M.", "" ] ]
We devise and demonstrate a method to search for non-gravitational couplings of ultralight dark matter to standard model particles using space-time separated atomic clocks and cavity-stabilized lasers. By making use of space-time separated sensors, which probe different values of an oscillating dark matter field, we can search for couplings that cancel in typical local experiments. We demonstrate this method using existing data from a frequency comparison of lasers stabilized to two optical cavities connected via a 2220 km fiber link [Nat. Commun. 13, 212 (2022)]. The absence of significant oscillations in the data results in constraints on the coupling of scalar dark matter to electrons, d_me, for masses between 1e-19 eV and 2e-15 eV. These are the first constraints on d_me alone in this mass range, and improve the dark matter constraints on any scalar-Fermion coupling by up to two orders of magnitude.
1606.03991
James Currie
James Currie, Thomas Gehrmann, Jan Niehues
Precise QCD predictions for the production of dijet final states in deep inelastic scattering
4 pages, 3 figures
Phys. Rev. Lett. 117, 042001 (2016)
10.1103/PhysRevLett.117.042001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of two-jet final states in deep inelastic scattering is an important QCD precision observable. We compute it for the first time to next-to-next-to-leading order (NNLO) in perturbative QCD. Our calculation is fully differential in the lepton and jet variables and allows one to impose cuts on the jets both in the laboratory and the Breit frame. We observe that the NNLO corrections are moderate in size, except at kinematical edges, and that their inclusion leads to a substantial reduction of the scale variation uncertainty on the predictions. Our results will enable the inclusion of deep inelastic dijet data in precision phenomenology studies.
[ { "created": "Mon, 13 Jun 2016 15:15:54 GMT", "version": "v1" } ]
2016-07-27
[ [ "Currie", "James", "" ], [ "Gehrmann", "Thomas", "" ], [ "Niehues", "Jan", "" ] ]
The production of two-jet final states in deep inelastic scattering is an important QCD precision observable. We compute it for the first time to next-to-next-to-leading order (NNLO) in perturbative QCD. Our calculation is fully differential in the lepton and jet variables and allows one to impose cuts on the jets both in the laboratory and the Breit frame. We observe that the NNLO corrections are moderate in size, except at kinematical edges, and that their inclusion leads to a substantial reduction of the scale variation uncertainty on the predictions. Our results will enable the inclusion of deep inelastic dijet data in precision phenomenology studies.
hep-ph/0106003
Valeri V. Kiselev
V.V.Kiselev
Evolution of flat universe with a cosmological term in modified Relativistic Theory of Gravitation as a scalar-tensor extension of General Relativity
23 pages, 3 eps-figures, title extended, arguements added, evolution eqs. unchanged, derivation and treatment of dimensional parameter improved
null
null
null
hep-ph astro-ph gr-qc hep-th
null
We consider the dynamics of tensor and scalar gravitational fields in the Relativistic Theory of Gravitation with the Minkowskian vacuum metric and generalize the formulation to the massless graviton. The potential of scalar field is determined in the presence of cosmological term under clear physical motivations. We find cosmological inflationary solutions and analyze conditions providing the transition to the regime of hot expanding universe.
[ { "created": "Fri, 1 Jun 2001 07:34:36 GMT", "version": "v1" }, { "created": "Thu, 7 Jun 2001 08:09:10 GMT", "version": "v2" }, { "created": "Wed, 17 Oct 2001 12:30:33 GMT", "version": "v3" }, { "created": "Thu, 4 Apr 2002 06:09:23 GMT", "version": "v4" } ]
2007-05-23
[ [ "Kiselev", "V. V.", "" ] ]
We consider the dynamics of tensor and scalar gravitational fields in the Relativistic Theory of Gravitation with the Minkowskian vacuum metric and generalize the formulation to the massless graviton. The potential of scalar field is determined in the presence of cosmological term under clear physical motivations. We find cosmological inflationary solutions and analyze conditions providing the transition to the regime of hot expanding universe.
2211.04716
Jerzy Kami\'nski
J. Z. Kami\'nski and K. Krajewska
Trident pair creation by a train of laser pulses: Resonance, threshold, and carrier envelope phase effects
15 pages, 9 figures
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
General formulation in the realm of strong-field quantum electrodynamics is provided for a process that occurs in the presence of a train of laser pulses and, in the tree level, is represented by a two-vertex Feynman diagram with exchange of a virtual photon. A scheme of retrieving resonances in the corresponding probability distributions is also formulated in these general settings. While the presented formalism is applicable to a variety of processes like electron-positron pair creation and annihilation, M\"oller scattering, Bhabha scattering, etc., we illustrate it for a trident process. Specifically, we consider electron-positron pair creation in the muon--laser-field collisions. We demonstrate that the probability distributions exhibit integrable singularities close to the threshold of pair creation. Also, a variety of resonances is observed that originate from the poles of the Feynman photon propagator. While those resonances are, in general, obscured by strong quantum interferences, we show that they can be isolated by changing the carrier envelope phase of the driving laser pulses. In that case, while transformed into the Lorentz-Breit-Wigner shape profile, the resonance position and width can be determined.
[ { "created": "Wed, 9 Nov 2022 07:19:50 GMT", "version": "v1" } ]
2022-11-10
[ [ "Kamiński", "J. Z.", "" ], [ "Krajewska", "K.", "" ] ]
General formulation in the realm of strong-field quantum electrodynamics is provided for a process that occurs in the presence of a train of laser pulses and, in the tree level, is represented by a two-vertex Feynman diagram with exchange of a virtual photon. A scheme of retrieving resonances in the corresponding probability distributions is also formulated in these general settings. While the presented formalism is applicable to a variety of processes like electron-positron pair creation and annihilation, M\"oller scattering, Bhabha scattering, etc., we illustrate it for a trident process. Specifically, we consider electron-positron pair creation in the muon--laser-field collisions. We demonstrate that the probability distributions exhibit integrable singularities close to the threshold of pair creation. Also, a variety of resonances is observed that originate from the poles of the Feynman photon propagator. While those resonances are, in general, obscured by strong quantum interferences, we show that they can be isolated by changing the carrier envelope phase of the driving laser pulses. In that case, while transformed into the Lorentz-Breit-Wigner shape profile, the resonance position and width can be determined.
hep-ph/0102335
Marc Vanderhaeghen
B. Pasquini, M. Gorchtein, D. Drechsel, A. Metz, and M. Vanderhaeghen
Dispersion relation formalism for virtual Compton scattering off the proton
51 pages, 15 figures
Eur.Phys.J. A11 (2001) 185-208
10.1007/s100500170084
null
hep-ph
null
We present in detail a dispersion relation formalism for virtual Compton scattering (VCS) off the proton from threshold into the $\Delta(1232)$-resonance region. Such a formalism can be used as a tool to extract the generalized polarizabilities of the proton from both unpolarized and polarized VCS observables over a larger energy range. We present calculations for existing and forthcoming VCS experiments and demonstrate that the VCS observables in the energy region between pion production threshold and the $\Delta(1232)$-resonance show an enhanced sensitivity to the generalized polarizabilities.
[ { "created": "Tue, 27 Feb 2001 19:48:48 GMT", "version": "v1" } ]
2016-09-06
[ [ "Pasquini", "B.", "" ], [ "Gorchtein", "M.", "" ], [ "Drechsel", "D.", "" ], [ "Metz", "A.", "" ], [ "Vanderhaeghen", "M.", "" ] ]
We present in detail a dispersion relation formalism for virtual Compton scattering (VCS) off the proton from threshold into the $\Delta(1232)$-resonance region. Such a formalism can be used as a tool to extract the generalized polarizabilities of the proton from both unpolarized and polarized VCS observables over a larger energy range. We present calculations for existing and forthcoming VCS experiments and demonstrate that the VCS observables in the energy region between pion production threshold and the $\Delta(1232)$-resonance show an enhanced sensitivity to the generalized polarizabilities.
hep-ph/9806416
Jose R. Pelaez
A. Dobado and J. R. Pelaez
Chiral symmetry and the pion gas virial expansion
16 Pages, 12 figures
Phys. Rev. D 59, 034004 (1998)
10.1103/PhysRevD.59.034004
SLAC-PUB-7857
hep-ph nucl-th
null
In this work we study the thermodynamic properties of the pion gas starting from the realistic elastic scattering phase-shifts obtained from Chiral Perturbation Theory and using the virial expansion. In particular we study the state equation and the behavior of the quark condensate as a function of the temperature and the density.
[ { "created": "Fri, 19 Jun 1998 02:49:10 GMT", "version": "v1" } ]
2016-08-25
[ [ "Dobado", "A.", "" ], [ "Pelaez", "J. R.", "" ] ]
In this work we study the thermodynamic properties of the pion gas starting from the realistic elastic scattering phase-shifts obtained from Chiral Perturbation Theory and using the virial expansion. In particular we study the state equation and the behavior of the quark condensate as a function of the temperature and the density.
hep-ph/0610433
C. Pallis
C. Pallis
CDM Abundance in non-Standard Cosmologies
Talk given at the 6th International Workshop on "The Identification of Dark Matter", 11-16 September 2006, Rhodes, Greece
null
10.1142/9789812770288_0080
null
hep-ph
null
The relic density of a cold dark matter (CDM) candidate is calculated in the context of three non-standard cosmological scenaria and its value is compared with the one obtained in the standard regime. In particular, we consider the decoupling of the CDM particle during: (i) A decaying-particle dominated phase or (ii) a kinetic-energy dominated phase or (iii) the decay of a massive particle under the complete or partial domination of kination. We use plausible values (from the viewpoint of supersymmetric models) for the mass and the thermal averaged cross section times the velocity of the cold relic and we investigate scenaria of equilibrium and non-equilibrium production. In the case (i) a low reheat temperature, in the range (1-20) GeV, significantly facilitates the achievement of an acceptable CDM abundance. On the other hand, the presence of kination in the case (ii) can lead to an enhancement of the CDM abundance up to three orders of magnitude. The latter enhancement can be avoided, in the case (iii). In a such situation, the temperature turns out to be frozen to a plateau value which is, mostly, lower than about 40 GeV.
[ { "created": "Tue, 31 Oct 2006 17:44:58 GMT", "version": "v1" } ]
2016-11-09
[ [ "Pallis", "C.", "" ] ]
The relic density of a cold dark matter (CDM) candidate is calculated in the context of three non-standard cosmological scenaria and its value is compared with the one obtained in the standard regime. In particular, we consider the decoupling of the CDM particle during: (i) A decaying-particle dominated phase or (ii) a kinetic-energy dominated phase or (iii) the decay of a massive particle under the complete or partial domination of kination. We use plausible values (from the viewpoint of supersymmetric models) for the mass and the thermal averaged cross section times the velocity of the cold relic and we investigate scenaria of equilibrium and non-equilibrium production. In the case (i) a low reheat temperature, in the range (1-20) GeV, significantly facilitates the achievement of an acceptable CDM abundance. On the other hand, the presence of kination in the case (ii) can lead to an enhancement of the CDM abundance up to three orders of magnitude. The latter enhancement can be avoided, in the case (iii). In a such situation, the temperature turns out to be frozen to a plateau value which is, mostly, lower than about 40 GeV.
hep-ph/9412349
Cheuk-Yin Wong
Lali Chatterjee and Cheuk-Yin Wong
Correction Factors for Reactions involving Quark-Antiquark Annihilation or Production
25 pages (REVTeX), includes 2 uuencoded compressed postscript figures
Phys.Rev.C51:2125-2134,1995
10.1103/PhysRevC.51.2125
ORNL-TH-941201
hep-ph
null
In reactions with $q \bar q$ production or $q\bar q$ annihilation, initial- and final-state interactions give rise to large corrections to the lowest-order cross sections. We evaluate the correction factor first for low relative kinetic energies by studying the distortion of the relative wave function. We then follow the procedure of Schwinger to interpolate this result with the well-known perturbative QCD vertex correction factors at high energies, to obtain an explicit semi-empirical correction factor applicable to the whole range of energies. The correction factor predicts an enhancement for $q\bar q$ in color-singlet states and a suppression for color-octet states, the effect increasing as the relative velocity decreases. Consequences on dilepton production in the quark-gluon plasma, the Drell-Yan process, and heavy quark production processes are discussed.
[ { "created": "Wed, 21 Dec 1994 20:07:17 GMT", "version": "v1" } ]
2009-09-25
[ [ "Chatterjee", "Lali", "" ], [ "Wong", "Cheuk-Yin", "" ] ]
In reactions with $q \bar q$ production or $q\bar q$ annihilation, initial- and final-state interactions give rise to large corrections to the lowest-order cross sections. We evaluate the correction factor first for low relative kinetic energies by studying the distortion of the relative wave function. We then follow the procedure of Schwinger to interpolate this result with the well-known perturbative QCD vertex correction factors at high energies, to obtain an explicit semi-empirical correction factor applicable to the whole range of energies. The correction factor predicts an enhancement for $q\bar q$ in color-singlet states and a suppression for color-octet states, the effect increasing as the relative velocity decreases. Consequences on dilepton production in the quark-gluon plasma, the Drell-Yan process, and heavy quark production processes are discussed.
2311.14475
Maxim Dvornikov
Mridupawan Deka (1), Maxim Dvornikov (1 and 2) ((1) JINR, (2) IZMIRAN)
Spin oscillations in neutrino gravitational scattering
7 pages in Revtex4.1, 6 eps figures; contribution to proceedings of XIX Workshop on High Energy Spin Physics, DSPIN-23 (September 4-8, 2023, JINR, Dubna, Russia); minimal changes; published in Phys.Atom.Nucl
Physics of Atomic Nuclei 87, 483-488 (2024)
10.1134/S1063778824700327
null
hep-ph astro-ph.HE gr-qc
http://creativecommons.org/licenses/by/4.0/
We study neutrino spin oscillations while the particles scatter off a rotating black hole surrounded by a thick magnetized accretion disk. Neutrino spin precession is caused by the interaction of the neutrino magnetic moment with the magnetic field in the disk which has both toroidal and poloidal components. Our calculation of the observed neutrino fluxes, accounting for spin oscillations, are based on numerical simulations of the propagation of a great number of incoming test particles using High Performance Parallel Computing. The obtained results significantly improve our previous findings. We briefly discuss the applications for the observations of astrophysical neutrinos.
[ { "created": "Fri, 24 Nov 2023 13:33:02 GMT", "version": "v1" }, { "created": "Wed, 7 Aug 2024 19:55:47 GMT", "version": "v2" } ]
2024-08-09
[ [ "Deka", "Mridupawan", "", "JINR" ], [ "Dvornikov", "Maxim", "", "1 and 2" ] ]
We study neutrino spin oscillations while the particles scatter off a rotating black hole surrounded by a thick magnetized accretion disk. Neutrino spin precession is caused by the interaction of the neutrino magnetic moment with the magnetic field in the disk which has both toroidal and poloidal components. Our calculation of the observed neutrino fluxes, accounting for spin oscillations, are based on numerical simulations of the propagation of a great number of incoming test particles using High Performance Parallel Computing. The obtained results significantly improve our previous findings. We briefly discuss the applications for the observations of astrophysical neutrinos.
2102.07159
Menglin Du Dr.
Meng-Lin Du, Vadim Baru, Feng-Kun Guo, Christoph Hanhart, Ulf-G. Mei{\ss}ner, Jos\'e A. Oller, and Qian Wang
Revisiting the nature of the $P_c$ pentaquarks
57 pages, 14 figures, and 13 tables
null
10.1007/JHEP08(2021)157
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The nature of the three narrow $P_c$ states, i.e., $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$, is under intense discussion since their discovery from the updated analysis by LHCb. In this work we extend our previous coupled-channel approach [Phys. Rev. Lett. \bf{124}, 072001 (2020)] by including the $\Lambda_c\bar{D}^{(*)}$ and $\eta_cp$ as explicitly in addition to the $J/\psi p$, as required by unitarity and heavy quark spin symmetry (HQSS). Since inelastic parameters are very badly constrained by the current data, three schemes are considered: (a) scheme I with pure contact interactions and without the $\Lambda_c\bar D^{(*)}$ interactions, (b) scheme II, where the one-pion exchange is added to scheme I, and (c) scheme III, where the $\Lambda_c \bar D^{(*)}$ are included in addition. It is shown that to obtain cutoff independent results, OPE in the multichannel system is to be supplemented with $S$-$D$ mixing contact terms. We demonstrate that the experimental data for the $J/\psi p$ invariant mass distribution are consistent with the interpretation of the $P_c(4312)$ and $P_c(4440)/P_c(4457)$ as $\Sigma_c\bar{D}$ and $\Sigma_c \bar{D}^{*}$ hadronic molecules, respectively, and that the data show clear evidence for a new narrow $P_c(4380)$, as a $\Sigma_c^*\bar D$ molecule, which should exist as a consequence of HQSS. While two equally good solutions are found in scheme I, only one of these solutions with the quantum numbers of the $P_c(4440)$ and $P_c(4457)$ being $J^P=3/2^-$ and $1/2^-$, respectively, survives the requirement of regulator independence once the OPE is included. Moreover, we predict the line shapes in the elastic and inelastic channels and demonstrate that those related to the $P_c(4440)$ and the $P_c(4457)$ in the corresponding $\Sigma_c^{(*)}\bar{D}$ and $\eta_cp$ mass distributions allow one to confirm the quantum numbers given above, once the data are available.
[ { "created": "Sun, 14 Feb 2021 14:07:56 GMT", "version": "v1" }, { "created": "Wed, 14 Jul 2021 17:18:37 GMT", "version": "v2" } ]
2022-11-09
[ [ "Du", "Meng-Lin", "" ], [ "Baru", "Vadim", "" ], [ "Guo", "Feng-Kun", "" ], [ "Hanhart", "Christoph", "" ], [ "Meißner", "Ulf-G.", "" ], [ "Oller", "José A.", "" ], [ "Wang", "Qian", "" ] ]
The nature of the three narrow $P_c$ states, i.e., $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$, is under intense discussion since their discovery from the updated analysis by LHCb. In this work we extend our previous coupled-channel approach [Phys. Rev. Lett. \bf{124}, 072001 (2020)] by including the $\Lambda_c\bar{D}^{(*)}$ and $\eta_cp$ as explicitly in addition to the $J/\psi p$, as required by unitarity and heavy quark spin symmetry (HQSS). Since inelastic parameters are very badly constrained by the current data, three schemes are considered: (a) scheme I with pure contact interactions and without the $\Lambda_c\bar D^{(*)}$ interactions, (b) scheme II, where the one-pion exchange is added to scheme I, and (c) scheme III, where the $\Lambda_c \bar D^{(*)}$ are included in addition. It is shown that to obtain cutoff independent results, OPE in the multichannel system is to be supplemented with $S$-$D$ mixing contact terms. We demonstrate that the experimental data for the $J/\psi p$ invariant mass distribution are consistent with the interpretation of the $P_c(4312)$ and $P_c(4440)/P_c(4457)$ as $\Sigma_c\bar{D}$ and $\Sigma_c \bar{D}^{*}$ hadronic molecules, respectively, and that the data show clear evidence for a new narrow $P_c(4380)$, as a $\Sigma_c^*\bar D$ molecule, which should exist as a consequence of HQSS. While two equally good solutions are found in scheme I, only one of these solutions with the quantum numbers of the $P_c(4440)$ and $P_c(4457)$ being $J^P=3/2^-$ and $1/2^-$, respectively, survives the requirement of regulator independence once the OPE is included. Moreover, we predict the line shapes in the elastic and inelastic channels and demonstrate that those related to the $P_c(4440)$ and the $P_c(4457)$ in the corresponding $\Sigma_c^{(*)}\bar{D}$ and $\eta_cp$ mass distributions allow one to confirm the quantum numbers given above, once the data are available.
hep-ph/0412203
Michael Chanowitz
Michael S. Chanowitz
The No-Higgs Signal: Strong WW Scattering at the LHC
16 pages, talk presented at Physics at LHC, July 13 - 17, 2004, Vienna, Austria, to be published in the proceedings
Czech.J.Phys.55:B45-B58,2005
null
LBNL-56734
hep-ph hep-ex
null
Strong WW scattering at the LHC is discussed as a manifestation of electroweak symmetry breaking in the absence of a light Higgs boson. The general framework of the Higgs mechanism -- with or without a Higgs boson -- is reviewed, and unitarity is shown to fix the scale of strong WW scattering. Strong WW scattering is also shown to be a possible outcome of five-dimensional models, which do not employ the usual Higgs mechanism at the TeV scale. Precision electroweak constraints are briefly discussed. Illustrative LHC signals are reviewed for models with QCD-like dynamics, stressing the complementarity of the W^{\pm}Z and like-charge W^+W^+ + W^-W^- channels.
[ { "created": "Tue, 14 Dec 2004 23:26:58 GMT", "version": "v1" } ]
2014-11-18
[ [ "Chanowitz", "Michael S.", "" ] ]
Strong WW scattering at the LHC is discussed as a manifestation of electroweak symmetry breaking in the absence of a light Higgs boson. The general framework of the Higgs mechanism -- with or without a Higgs boson -- is reviewed, and unitarity is shown to fix the scale of strong WW scattering. Strong WW scattering is also shown to be a possible outcome of five-dimensional models, which do not employ the usual Higgs mechanism at the TeV scale. Precision electroweak constraints are briefly discussed. Illustrative LHC signals are reviewed for models with QCD-like dynamics, stressing the complementarity of the W^{\pm}Z and like-charge W^+W^+ + W^-W^- channels.
hep-ph/0406268
Wan-lei Guo
Wan-lei Guo
Neutrino Mixing and Leptogenesis in Type II Seesaw Mechanism
RevTex 14 pages, 1 table. More discussions and references added. To appear in Phys. Rev. D
Phys.Rev.D70:053009,2004
10.1103/PhysRevD.70.053009
null
hep-ph
null
In the framework of type II seesaw mechanism we propose two simple but instructive ansatze for neutrino mixing and leptogenesis. In each ansatz, the effective Majorana neutrino mass matrix is composed of two parts -- the part with Z_2 symmetry arises from the ordinary type I seesaw mechanism and the part with S_3 symmetry arises from an additional Higgs triplet vacuum expectation value. The two ansatze can simultaneously account for the current neutrino oscillation data and the cosmological baryon number asymmetry via leptogenesis.
[ { "created": "Thu, 24 Jun 2004 08:29:32 GMT", "version": "v1" }, { "created": "Sun, 22 Aug 2004 11:15:24 GMT", "version": "v2" } ]
2008-11-26
[ [ "Guo", "Wan-lei", "" ] ]
In the framework of type II seesaw mechanism we propose two simple but instructive ansatze for neutrino mixing and leptogenesis. In each ansatz, the effective Majorana neutrino mass matrix is composed of two parts -- the part with Z_2 symmetry arises from the ordinary type I seesaw mechanism and the part with S_3 symmetry arises from an additional Higgs triplet vacuum expectation value. The two ansatze can simultaneously account for the current neutrino oscillation data and the cosmological baryon number asymmetry via leptogenesis.
1207.7052
Pietro Santorelli
Thomas Gutsche, Mikhail A. Ivanov, Jurgen G. Korner, Valery E. Lyubovitskij, Pietro Santorelli
Light baryons and their electromagnetic interactions in the covariant constituent quark model
18 pages, 7 figures
null
10.1103/PhysRevD.86.074013
DSF-2012-4 (Napoli); MZ-TH/12-31 (Mainz)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the confined covariant constituent quark model that was previously developed by us for mesons to the baryon sector. In our numerical calculation we use the same values for the constituent quark masses and the infrared cutoff as have been previously used in the meson sector. In a first application we describe the static properties of the proton and neutron, and the $\Lambda$-hyperon (magnetic moments and charge radii) and the behavior of the nucleon form factors at low momentum transfers. We discuss in some detail the conservation of gauge invariance of the electromagnetic transition matrix elements in the presence of a nonlocal coupling of the baryons to the three constituent quark fields.
[ { "created": "Mon, 30 Jul 2012 19:32:49 GMT", "version": "v1" } ]
2013-05-30
[ [ "Gutsche", "Thomas", "" ], [ "Ivanov", "Mikhail A.", "" ], [ "Korner", "Jurgen G.", "" ], [ "Lyubovitskij", "Valery E.", "" ], [ "Santorelli", "Pietro", "" ] ]
We extend the confined covariant constituent quark model that was previously developed by us for mesons to the baryon sector. In our numerical calculation we use the same values for the constituent quark masses and the infrared cutoff as have been previously used in the meson sector. In a first application we describe the static properties of the proton and neutron, and the $\Lambda$-hyperon (magnetic moments and charge radii) and the behavior of the nucleon form factors at low momentum transfers. We discuss in some detail the conservation of gauge invariance of the electromagnetic transition matrix elements in the presence of a nonlocal coupling of the baryons to the three constituent quark fields.
2312.08332
Lindber Salas
Alex Pomarol and Lindber Salas
Exploring the conformal transition from above and below
19 pages, 5 figures
null
null
null
hep-ph hep-lat hep-th
http://creativecommons.org/licenses/by/4.0/
We consider conformal transitions arising from the merging of IR and UV fixed points, expected to occur in QCD with a large enough number of flavors. We study the smoothness of physical quantities across this transition, being mostly determined by the logarithmic breaking of conformal invariance. We investigate this explicitly using holography where approaching the conformal transition either from outside or inside the conformal window (perturbed by a mass term) is characterized by the same dynamics. The mass of spin-1 mesons and $F_\pi$ are shown to be continuous across the transition, as well as the dilaton mass. This implies that the lightness of the dilaton cannot be a consequence of the spontaneous breaking of scale invariance when leaving the conformal window. Our analysis suggests that the light scalar observed in QCD lattice simulations is a $q\bar q$ meson that becomes light since the $q\bar q$-operator dimension reaches its minimal value.
[ { "created": "Wed, 13 Dec 2023 18:08:38 GMT", "version": "v1" } ]
2023-12-18
[ [ "Pomarol", "Alex", "" ], [ "Salas", "Lindber", "" ] ]
We consider conformal transitions arising from the merging of IR and UV fixed points, expected to occur in QCD with a large enough number of flavors. We study the smoothness of physical quantities across this transition, being mostly determined by the logarithmic breaking of conformal invariance. We investigate this explicitly using holography where approaching the conformal transition either from outside or inside the conformal window (perturbed by a mass term) is characterized by the same dynamics. The mass of spin-1 mesons and $F_\pi$ are shown to be continuous across the transition, as well as the dilaton mass. This implies that the lightness of the dilaton cannot be a consequence of the spontaneous breaking of scale invariance when leaving the conformal window. Our analysis suggests that the light scalar observed in QCD lattice simulations is a $q\bar q$ meson that becomes light since the $q\bar q$-operator dimension reaches its minimal value.
1705.07870
Andrei Angelescu
Andrei Angelescu
Scalar Production in Association with a Z Boson at LHC and ILC: the Mixed BEH-Radion Case of Warped Models
4 pages, 2 figures, Contribution to the proceedings of the 52nd Rencontres de Moriond 2017, EW Session; based on arXiv:1702.03984
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The radion scalar field might be the lightest new particle predicted by extra-dimensional extensions of the Standard Model, thus possibly leading to the first signatures of new physics at the LHC. We perform a study of its production in association with a $Z$ boson in the custodially protected warped model with a brane-localised Higgs boson addressing the gauge hierarchy problem, with Higgs-radion mixing effects included. While the considered radion production at the LHC would constrain some parts of the parameter space, it is only the ILC program that will be able to cover a significant part of this space through the studied process. Complementary tests of the same theoretical parameters can be realised through the high accuracy measurements of the Higgs couplings at ILC.
[ { "created": "Mon, 22 May 2017 17:31:33 GMT", "version": "v1" } ]
2017-05-23
[ [ "Angelescu", "Andrei", "" ] ]
The radion scalar field might be the lightest new particle predicted by extra-dimensional extensions of the Standard Model, thus possibly leading to the first signatures of new physics at the LHC. We perform a study of its production in association with a $Z$ boson in the custodially protected warped model with a brane-localised Higgs boson addressing the gauge hierarchy problem, with Higgs-radion mixing effects included. While the considered radion production at the LHC would constrain some parts of the parameter space, it is only the ILC program that will be able to cover a significant part of this space through the studied process. Complementary tests of the same theoretical parameters can be realised through the high accuracy measurements of the Higgs couplings at ILC.
0901.3589
Bin Zhang
Anupama Atre, Tao Han, Silvia Pascoli, Bin Zhang
The Search for Heavy Majorana Neutrinos
60 pages, 27 figures, minor changes,some references added, matches the published version
JHEP 0905:030,2009
10.1088/1126-6708/2009/05/030
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
The Majorana nature of neutrinos can be experimentally verified only via {\it lepton-number} violating processes involving charged leptons. We study 36 lepton-number violating ($\lv$) processes from the decays of tau leptons and pseudoscalar mesons. These decays are absent in the Standard Model but, in presence of Majorana neutrinos in the mass range $\sim 100 \mev$ to $5 \gev$, the rates for these processes would be enhanced due to their resonant contribution. We calculate the transition rates and branching fractions and compare them to the current bounds from direct experimental searches for $\dl=2$ tau and rare meson decays. The experimental non-observation of such $\lv$ processes places stringent bounds on the Majorana neutrino mass and mixing and we summarize the existing limits. We also extend the search to hadron collider experiments. We find that, at the Tevatron with $8 {fb}^{-1}$ integrated luminosity, there could be $2\sigma$ ($5\sigma$) sensitivity for resonant production of a Majorana neutrino in the $\mu^\pm \mu^\pm$ modes in the mass range of $\sim 10 - 180 {\gev} (10 - 120 {\gev})$. This reach can be extended to $\sim 10 - 375 {\gev} (10 - 250 mbox{\gev})$ at the LHC of 14 TeV with $100 {fb}^{-1}$. The production cross section at the LHC of 10 TeV is also presented for comparison. We study the $\mu^\pm e^\pm$ modes as well and find that the signal could be large enough even taking into account the current bound from neutrinoless double-beta decay. The signal from the gauge boson fusion channel $W^+ W^+\to \ell^+_1 \ell^+_2$ at the LHC is found to be very weak given the rather small mixing parameters. We comment on the search strategy when a $\tau$ lepton is involved in the final state.
[ { "created": "Fri, 23 Jan 2009 02:30:42 GMT", "version": "v1" }, { "created": "Thu, 7 May 2009 14:36:32 GMT", "version": "v2" } ]
2015-03-13
[ [ "Atre", "Anupama", "" ], [ "Han", "Tao", "" ], [ "Pascoli", "Silvia", "" ], [ "Zhang", "Bin", "" ] ]
The Majorana nature of neutrinos can be experimentally verified only via {\it lepton-number} violating processes involving charged leptons. We study 36 lepton-number violating ($\lv$) processes from the decays of tau leptons and pseudoscalar mesons. These decays are absent in the Standard Model but, in presence of Majorana neutrinos in the mass range $\sim 100 \mev$ to $5 \gev$, the rates for these processes would be enhanced due to their resonant contribution. We calculate the transition rates and branching fractions and compare them to the current bounds from direct experimental searches for $\dl=2$ tau and rare meson decays. The experimental non-observation of such $\lv$ processes places stringent bounds on the Majorana neutrino mass and mixing and we summarize the existing limits. We also extend the search to hadron collider experiments. We find that, at the Tevatron with $8 {fb}^{-1}$ integrated luminosity, there could be $2\sigma$ ($5\sigma$) sensitivity for resonant production of a Majorana neutrino in the $\mu^\pm \mu^\pm$ modes in the mass range of $\sim 10 - 180 {\gev} (10 - 120 {\gev})$. This reach can be extended to $\sim 10 - 375 {\gev} (10 - 250 mbox{\gev})$ at the LHC of 14 TeV with $100 {fb}^{-1}$. The production cross section at the LHC of 10 TeV is also presented for comparison. We study the $\mu^\pm e^\pm$ modes as well and find that the signal could be large enough even taking into account the current bound from neutrinoless double-beta decay. The signal from the gauge boson fusion channel $W^+ W^+\to \ell^+_1 \ell^+_2$ at the LHC is found to be very weak given the rather small mixing parameters. We comment on the search strategy when a $\tau$ lepton is involved in the final state.
hep-ph/0510092
Alexei Nefediev
A.V.Nefediev, Yu.A.Simonov (ITEP, Moscow)
QCD string and the Lorentz nature of confinement
LaTeX2e, 5 pages, uses jetpl.cls (included), to appear in JETP Lett
JETP Lett. 82 (2005) 557-561; Pisma Zh.Eksp.Teor.Fiz. 82 (2005) 633-637
10.1134/1.2161280
null
hep-ph
null
We address the question of the Lorentz nature of the effective long-range interquark interaction generated by the QCD string with quarks at the ends. Studying the Dyson-Schwinger equation for a heavy-light quark-antiquark system, we demonstrate explicitly how a Lorentz-scalar interaction appears in the Diraclike equation for the light quark, as a consequence of chiral symmetry breaking. We argue that the effective interquark interaction in the Hamiltonian of the QCD string with quarks at the ends stems from this effective scalar interaction.
[ { "created": "Fri, 7 Oct 2005 12:09:33 GMT", "version": "v1" } ]
2009-11-11
[ [ "Nefediev", "A. V.", "", "ITEP, Moscow" ], [ "Simonov", "Yu. A.", "", "ITEP, Moscow" ] ]
We address the question of the Lorentz nature of the effective long-range interquark interaction generated by the QCD string with quarks at the ends. Studying the Dyson-Schwinger equation for a heavy-light quark-antiquark system, we demonstrate explicitly how a Lorentz-scalar interaction appears in the Diraclike equation for the light quark, as a consequence of chiral symmetry breaking. We argue that the effective interquark interaction in the Hamiltonian of the QCD string with quarks at the ends stems from this effective scalar interaction.
1408.0961
Kei Yagyu
Hiroshi Okada, Takashi Toma and Kei Yagyu
Inert Extension of the Zee-Babu Model
21 pages, 6 figures
Phys. Rev. D 90, 095005 (2014)
10.1103/PhysRevD.90.095005
DCPT-14-146, IPPP-14-73, KIAS-P14049
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a two-loop induced Zee-Babu type neutrino mass model at the TeV scale. Although there is no dark matter candidate in the original Zee-Babu model, that is contained in our model by introducing an unbroken discrete $Z_2$ symmetry. The discrepancy between the experimental value of the muon anomalous magnetic moment (muon $g-2$) and its prediction in the standard model can be explained by contributions from additional vector-like charged-leptons which are necessary to give non-zero neutrino masses. The mass of vector-like leptons to be slightly above 300 GeV is favored and allowed from the muon $g-2$ and the current LHC data. We find that from the structure of neutrino mass matrix, doubly-charged scalar bosons in our model can mainly decay into the same-sign and same-flavour dilepton plus missing transverse momentum. By measuring an excess of these events at the LHC, our model can be distinguished from the other models including doubly-charged scalar bosons.
[ { "created": "Tue, 5 Aug 2014 13:32:48 GMT", "version": "v1" } ]
2014-11-11
[ [ "Okada", "Hiroshi", "" ], [ "Toma", "Takashi", "" ], [ "Yagyu", "Kei", "" ] ]
We propose a two-loop induced Zee-Babu type neutrino mass model at the TeV scale. Although there is no dark matter candidate in the original Zee-Babu model, that is contained in our model by introducing an unbroken discrete $Z_2$ symmetry. The discrepancy between the experimental value of the muon anomalous magnetic moment (muon $g-2$) and its prediction in the standard model can be explained by contributions from additional vector-like charged-leptons which are necessary to give non-zero neutrino masses. The mass of vector-like leptons to be slightly above 300 GeV is favored and allowed from the muon $g-2$ and the current LHC data. We find that from the structure of neutrino mass matrix, doubly-charged scalar bosons in our model can mainly decay into the same-sign and same-flavour dilepton plus missing transverse momentum. By measuring an excess of these events at the LHC, our model can be distinguished from the other models including doubly-charged scalar bosons.
2004.14856
Alexandros Kehagias
K. Farakos, A. Kehagias and G. Koutsoumbas
Gauge Field Localization in the Linear Dilaton Background
16 pages, 7 figures
null
10.1016/j.physletb.2020.135549
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study dynamical self-localization of gauge theories in higher dimensions. Specifically, we consider a 5D $U(1)$ gauge theory in the linear dilaton (clockwork) background, with anisotropic gauge couplings along the transverse (fifth) direction and the longitudinal (four-dimensional) directions. By using lattice techniques, we calculate the space plaquettes and the helicity moduli and we determine the phase diagram of the model. We find strong evidence that the model exhibits a new phase, a layer phase, where the four-dimensional physics decouples from the five-dimensional dynamics. The layer phase corresponds to a strong force along the fifth direction and a Coulomb phase along the four-dimensional longitudinal directions. This is in accordance with the clockwork mechanism where light particles with exponentially suppressed interactions are generated in theories with no fundamental small parameters.
[ { "created": "Wed, 29 Apr 2020 17:56:05 GMT", "version": "v1" } ]
2020-06-24
[ [ "Farakos", "K.", "" ], [ "Kehagias", "A.", "" ], [ "Koutsoumbas", "G.", "" ] ]
We study dynamical self-localization of gauge theories in higher dimensions. Specifically, we consider a 5D $U(1)$ gauge theory in the linear dilaton (clockwork) background, with anisotropic gauge couplings along the transverse (fifth) direction and the longitudinal (four-dimensional) directions. By using lattice techniques, we calculate the space plaquettes and the helicity moduli and we determine the phase diagram of the model. We find strong evidence that the model exhibits a new phase, a layer phase, where the four-dimensional physics decouples from the five-dimensional dynamics. The layer phase corresponds to a strong force along the fifth direction and a Coulomb phase along the four-dimensional longitudinal directions. This is in accordance with the clockwork mechanism where light particles with exponentially suppressed interactions are generated in theories with no fundamental small parameters.
hep-ph/0209261
Mijail Braun
M.A.Braun and B.Vlahovic
Estimates of the subthreshold production of charm
5 pages text in LaTex, 3 figures in PS
null
null
US-FT/17-99
hep-ph
null
Charm photoproduction rates off nuclei below the nucleon threshold are estimated using the phenomenologically known structure functions both for $x<1$ and $x>1$. The rates rapidly fall from values of the order 1 nb at the threshold to values of the order 1 pb at 6 GeV for Pb target.
[ { "created": "Mon, 23 Sep 2002 16:32:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Braun", "M. A.", "" ], [ "Vlahovic", "B.", "" ] ]
Charm photoproduction rates off nuclei below the nucleon threshold are estimated using the phenomenologically known structure functions both for $x<1$ and $x>1$. The rates rapidly fall from values of the order 1 nb at the threshold to values of the order 1 pb at 6 GeV for Pb target.
hep-ph/0102319
Hans Volker Klapdor
H.V. Klapdor-Kleingrothaus (MPI-Kernphysik, Heidelberg, Germany)
New Physics in the New Millennium with GENIUS: Double Beta Decay, Dark Matter, Solar Neutrinos
20 pages, revtex, 17 figures, Talk was presented at International Workshop on Non-Accelerator New Physics in Neutrino Observations (NANPino), Dubna, Russia, July 19-22, 2000, to be publ. in Particles and Nuclei, Letters, issues 1/2 in 2001, Conference Info - Home Page: http://www.nanp.ru/2000/, Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc/
Part.Nucl.Lett. 104 (2001) 20-39
null
null
hep-ph
null
Double beta decay is indispensable to solve the question of the neutrino mass matrix together with $\nu$ oscillation experiments. The most sensitive experiment since eight years - the Heidelberg-Moscow experiment in Gran-Sasso - already now, with the experimental limit of $<m_\nu > < 0.26$ eV excludes degenerate $\nu$ mass scenarios allowing neutrinos as hot dark matter in the universe for the small angle MSW solution of the solar neutrino problem. It probes cosmological models including hot dark matter already now on the level of future satellite experiments MAP and PLANCK. It further probes many topics of beyond Standard Model physics at the TeV scale. Future experiments should give access to the multi-TeV range and complement on many ways the search for new physics at future colliders like LHC and NLC. For neutrino physics some of them (GENIUS) will allow to test almost all neutrino mass scenarios allowed by the present neutrino oscillation experiments. At the same time GENIUS will cover a wide range of the parameter space of predictions of SUSY for neutralinos as cold dark matter. Further it has the potential to be a real-time detector for low-energy ($pp$ and $^7$Be) solar neutrinos. A GENIUS Test Facility has just been funded and will come into operation by end of 2001.
[ { "created": "Mon, 26 Feb 2001 17:37:13 GMT", "version": "v1" } ]
2009-09-25
[ [ "Klapdor-Kleingrothaus", "H. V.", "", "MPI-Kernphysik, Heidelberg, Germany" ] ]
Double beta decay is indispensable to solve the question of the neutrino mass matrix together with $\nu$ oscillation experiments. The most sensitive experiment since eight years - the Heidelberg-Moscow experiment in Gran-Sasso - already now, with the experimental limit of $<m_\nu > < 0.26$ eV excludes degenerate $\nu$ mass scenarios allowing neutrinos as hot dark matter in the universe for the small angle MSW solution of the solar neutrino problem. It probes cosmological models including hot dark matter already now on the level of future satellite experiments MAP and PLANCK. It further probes many topics of beyond Standard Model physics at the TeV scale. Future experiments should give access to the multi-TeV range and complement on many ways the search for new physics at future colliders like LHC and NLC. For neutrino physics some of them (GENIUS) will allow to test almost all neutrino mass scenarios allowed by the present neutrino oscillation experiments. At the same time GENIUS will cover a wide range of the parameter space of predictions of SUSY for neutralinos as cold dark matter. Further it has the potential to be a real-time detector for low-energy ($pp$ and $^7$Be) solar neutrinos. A GENIUS Test Facility has just been funded and will come into operation by end of 2001.
hep-ph/0106143
Volker Burkert
Volker D. Burkert (Jefferson Lab)
Excitation of Nucleon Resonances
9 pages, 2 figures
null
10.1142/9789812810878_0071
JLAB-PHY-01-13
hep-ph nucl-ex nucl-th
null
I discuss developments in the area of nucleon resonance excitations that are necessary to bring our understanding of nucleon structure in the regime of strong QCD to a qualitatively new level. They involve the collection of high quality data in various channels, a more rigorous approach in the search for "missing" quark model states, an effort to compute some critical quantities in nucleon resonance excitations from first principles, i.e. QCD, and a proposal aimed at obtaining an understanding of a fundamental quantity in nucleon structure.
[ { "created": "Thu, 14 Jun 2001 01:47:14 GMT", "version": "v1" } ]
2017-08-23
[ [ "Burkert", "Volker D.", "", "Jefferson Lab" ] ]
I discuss developments in the area of nucleon resonance excitations that are necessary to bring our understanding of nucleon structure in the regime of strong QCD to a qualitatively new level. They involve the collection of high quality data in various channels, a more rigorous approach in the search for "missing" quark model states, an effort to compute some critical quantities in nucleon resonance excitations from first principles, i.e. QCD, and a proposal aimed at obtaining an understanding of a fundamental quantity in nucleon structure.
hep-ph/9801455
Tanmay Vachaspati
Junseong Heo (Yale) and Tanmay Vachaspati (CWRU)
Z_3 Strings and their Interactions
8 pages; mainly corrected typos in tables
Phys.Rev. D58 (1998) 065011
10.1103/PhysRevD.58.065011
CWRU-P7-1998
hep-ph hep-th
null
We construct Z_3 vortex solutions in a model in which SU(3) is spontaneously broken to Z_3. The model is truncated to one in which there are only two dimensionless free parameters and the interaction of vortices within this restricted set of models is studied numerically. We find that there is a curve in the two dimensional space of parameters for which the energy of two asymptotically separated vortices equals the energy of the vortices at vanishing separation. This suggests that the inter-vortex potential for Z_3 strings might be flat for these couplings, much like the case of U(1) strings in the Bogomolnyi limit. However, we argue that the intervortex potential is attractive at short distances and repulsive at large separations leading to the possibility of unstable bound states of Z_3 vortices.
[ { "created": "Fri, 30 Jan 1998 16:56:16 GMT", "version": "v1" }, { "created": "Mon, 6 Jul 1998 20:57:25 GMT", "version": "v2" } ]
2009-10-31
[ [ "Heo", "Junseong", "", "Yale" ], [ "Vachaspati", "Tanmay", "", "CWRU" ] ]
We construct Z_3 vortex solutions in a model in which SU(3) is spontaneously broken to Z_3. The model is truncated to one in which there are only two dimensionless free parameters and the interaction of vortices within this restricted set of models is studied numerically. We find that there is a curve in the two dimensional space of parameters for which the energy of two asymptotically separated vortices equals the energy of the vortices at vanishing separation. This suggests that the inter-vortex potential for Z_3 strings might be flat for these couplings, much like the case of U(1) strings in the Bogomolnyi limit. However, we argue that the intervortex potential is attractive at short distances and repulsive at large separations leading to the possibility of unstable bound states of Z_3 vortices.
hep-ph/9611318
Alexander V. Kisselev
A.V. Kisselev and V.A. Petrov
Dependence of Deep Inelastic Structure Functions on Quark Masses
13 pages, plain LaTeX, 3 figures
Phys.Atom.Nucl.60:1533-1539,1997; Yad.Fiz.60:1680-1687,1997
null
IHEP 96-88
hep-ph
null
We argue that the difference between the structure functions corresponding to deep inelastic scattering with and without heavy quarks in the current fragmentation region scales at high $Q^2$ and fixed (low) $x_{Bj}$. The lower bound on charm contribution to the total structure function, $F_2^c(Q^2,x)$, is calculated and compared with the recent data on $F_2^c(Q^2,x)$ from H1 Collaboration.
[ { "created": "Wed, 13 Nov 1996 17:29:33 GMT", "version": "v1" } ]
2011-01-25
[ [ "Kisselev", "A. V.", "" ], [ "Petrov", "V. A.", "" ] ]
We argue that the difference between the structure functions corresponding to deep inelastic scattering with and without heavy quarks in the current fragmentation region scales at high $Q^2$ and fixed (low) $x_{Bj}$. The lower bound on charm contribution to the total structure function, $F_2^c(Q^2,x)$, is calculated and compared with the recent data on $F_2^c(Q^2,x)$ from H1 Collaboration.
2408.01296
Thomas G. Rizzo
Thomas G. Rizzo
Towards UV Models of Kinetic Mixing and Portal Matter: A More Complex Dark Matter Sector?
26 pages, 6 figs; text and refs updated
null
null
SLAC-PUB-17779
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Portal Matter, with both SM and dark charges, induces KM between the $U(1)_D$ dark photon and the SM gauge fields offering an attractive mechanism by which light thermal DM can obtain its observed relic density. If DM is fermionic, the CMB informs us that it must be Majorana/pseudo-Dirac in nature to avoid temperature-independent $s$-wave annihilation to SM states. How does this fit into a more complete picture with the SM? A first step along this path may not lie far away in energy due to the RGE running of the dark gauge coupling which can becomes non-perturbative before the $\sim 10$'s of TeV range. This implies that $U(1)_D$ must become embedded in a non-Abelian group, $G_D$, before this occurs. The breaking of this group then produces the PM masses and the heavy gauge fields associated with $G_D$ lead to new interactions between the SM and the dark sector. In the past we have examined a set of distinctive phenomenological features associated with this setup, based upon a number of simplifying assumptions. It behooves us to explore the impact of these assumptions on the predictions for possible experimental tests of these models. In past analyses we assumed that DM is a VL, complex singlet under $G_D$. If this assumption is relaxed, the dark sector must be augmented by additional fermion(s) and the scalar fields needed to break the symmetries while generating the needed Majorana-like mass terms for the DM. Here we analyze the simplest extension of this kind wherein the DM lies in a VL doublet of $G_D$, which we take to have the structure $SU(2)_I\times U(1)_{Y_I}$, leading to new phenomenology. We find that given the current LHC search constraints on the masses of heavy gauge bosons, the production of these new dark states with large rates is unlikely at colliders unless they are produced singly in $gg$-fusion or are resonantly enhanced.
[ { "created": "Fri, 2 Aug 2024 14:36:22 GMT", "version": "v1" }, { "created": "Wed, 14 Aug 2024 23:52:01 GMT", "version": "v2" } ]
2024-08-16
[ [ "Rizzo", "Thomas G.", "" ] ]
Portal Matter, with both SM and dark charges, induces KM between the $U(1)_D$ dark photon and the SM gauge fields offering an attractive mechanism by which light thermal DM can obtain its observed relic density. If DM is fermionic, the CMB informs us that it must be Majorana/pseudo-Dirac in nature to avoid temperature-independent $s$-wave annihilation to SM states. How does this fit into a more complete picture with the SM? A first step along this path may not lie far away in energy due to the RGE running of the dark gauge coupling which can becomes non-perturbative before the $\sim 10$'s of TeV range. This implies that $U(1)_D$ must become embedded in a non-Abelian group, $G_D$, before this occurs. The breaking of this group then produces the PM masses and the heavy gauge fields associated with $G_D$ lead to new interactions between the SM and the dark sector. In the past we have examined a set of distinctive phenomenological features associated with this setup, based upon a number of simplifying assumptions. It behooves us to explore the impact of these assumptions on the predictions for possible experimental tests of these models. In past analyses we assumed that DM is a VL, complex singlet under $G_D$. If this assumption is relaxed, the dark sector must be augmented by additional fermion(s) and the scalar fields needed to break the symmetries while generating the needed Majorana-like mass terms for the DM. Here we analyze the simplest extension of this kind wherein the DM lies in a VL doublet of $G_D$, which we take to have the structure $SU(2)_I\times U(1)_{Y_I}$, leading to new phenomenology. We find that given the current LHC search constraints on the masses of heavy gauge bosons, the production of these new dark states with large rates is unlikely at colliders unless they are produced singly in $gg$-fusion or are resonantly enhanced.
2006.15672
Daneng Yang
Haipeng An, Daneng Yang
Direct detection of freeze-in inelastic dark matter
7 pages, 7 figures
Physics Letters B, Volume 818, 10 July 2021, 136408
10.1016/j.physletb.2021.136408
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the current sensitivities of direct detection experiments have already reached the interesting parameter space of freeze-in dark matter models if the dark sector is in the inelastic dark matter framework and the excited dark matter state is cosmologically stable. Using results recently presented by the XENON1T experiment, we present constraints on these models. We also show that these models can explain the reported excess in the electron recoil signals if the mass gap between the ground state and the excited state is at keV scale.
[ { "created": "Sun, 28 Jun 2020 18:14:35 GMT", "version": "v1" }, { "created": "Wed, 1 Jul 2020 13:47:47 GMT", "version": "v2" }, { "created": "Fri, 28 May 2021 06:48:36 GMT", "version": "v3" } ]
2021-05-31
[ [ "An", "Haipeng", "" ], [ "Yang", "Daneng", "" ] ]
We show that the current sensitivities of direct detection experiments have already reached the interesting parameter space of freeze-in dark matter models if the dark sector is in the inelastic dark matter framework and the excited dark matter state is cosmologically stable. Using results recently presented by the XENON1T experiment, we present constraints on these models. We also show that these models can explain the reported excess in the electron recoil signals if the mass gap between the ground state and the excited state is at keV scale.
hep-ph/9504259
Masahiro Tanaka
Masahiro Tanaka (Tohoku University)
Three Generations or More for an Attractive Gravity?
17 pages, no figure
Phys.Rev. D53 (1996) 6941-6945
10.1103/PhysRevD.53.6941
TU-481
hep-ph gr-qc
null
We calculate the induced Einstein action from supersymmetric models in general space-time. Supersymmetric models consist of two kinds of supermultiplets, called scalar supermultiplets and vector supermultiplets, respectively. We show that the vector multiplets generate a negative Newton constant, while the scalar multiplets a positive one. Then we find that the positivity of Newton constant depends on the ratio of the number of scalar multiplets to one of vector multiplets. If we apply this result to two hopeful supersymmetric unified models: one is minimal SUSY standard model and another is minimal SUSY SU(5) GUT, we are led to the conclusion that we need more than or equal to three generations of quark and lepton multiplets to have a positive Newton constant, i.e., an attractive gravity.
[ { "created": "Sat, 8 Apr 1995 03:51:07 GMT", "version": "v1" } ]
2009-10-28
[ [ "Tanaka", "Masahiro", "", "Tohoku University" ] ]
We calculate the induced Einstein action from supersymmetric models in general space-time. Supersymmetric models consist of two kinds of supermultiplets, called scalar supermultiplets and vector supermultiplets, respectively. We show that the vector multiplets generate a negative Newton constant, while the scalar multiplets a positive one. Then we find that the positivity of Newton constant depends on the ratio of the number of scalar multiplets to one of vector multiplets. If we apply this result to two hopeful supersymmetric unified models: one is minimal SUSY standard model and another is minimal SUSY SU(5) GUT, we are led to the conclusion that we need more than or equal to three generations of quark and lepton multiplets to have a positive Newton constant, i.e., an attractive gravity.
hep-ph/0303245
Gerhart Seidl
K.R.S. Balaji, Manfred Lindner, Gerhart Seidl
Seesaw Neutrino Masses with Large Mixings from Dimensional Deconstruction
Revised version published in PRL
Phys.Rev.Lett. 91 (2003) 161803
10.1103/PhysRevLett.91.161803
TUM-HEP-503/03, DO-TH 03/05
hep-ph astro-ph
null
We demonstrate a dynamical origin for the dimension-five seesaw operator in dimensional deconstruction models. Light neutrino masses arise from the seesaw scale which corresponds to the inverse lattice spacing. It is shown that the deconstructing limit naturally prefers maximal leptonic mixing. Higher-order corrections which are allowed by gauge invariance can transform the bi-maximal into a bi-large mixing. These terms may appear to be non-renormalizable at scales smaller than the deconstruction scale.
[ { "created": "Fri, 28 Mar 2003 16:14:10 GMT", "version": "v1" }, { "created": "Tue, 8 Apr 2003 13:07:02 GMT", "version": "v2" }, { "created": "Tue, 22 Apr 2003 11:04:44 GMT", "version": "v3" }, { "created": "Sat, 25 Oct 2003 23:03:02 GMT", "version": "v4" } ]
2016-09-06
[ [ "Balaji", "K. R. S.", "" ], [ "Lindner", "Manfred", "" ], [ "Seidl", "Gerhart", "" ] ]
We demonstrate a dynamical origin for the dimension-five seesaw operator in dimensional deconstruction models. Light neutrino masses arise from the seesaw scale which corresponds to the inverse lattice spacing. It is shown that the deconstructing limit naturally prefers maximal leptonic mixing. Higher-order corrections which are allowed by gauge invariance can transform the bi-maximal into a bi-large mixing. These terms may appear to be non-renormalizable at scales smaller than the deconstruction scale.
1505.03496
Jonas Scheunert
Jonas Scheunert, Pedro Bicudo, Annabelle Uenver, Marc Wagner
Refined lattice/model investigation of $u d \bar{b} \bar{b}$ tetraquark candidates with heavy spin effects taken into account
6 pages, 1 figure, talk given at "Excited QCD 2015", Tatransk\'a Lomnica, Slovakia, March 8-14, 2015
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate four-quark systems consisting of two heavy anti-bottom quarks and two light up/down quarks. We propose to solve a coupled Schr\"odinger equation for the anti-bottom-anti-bottom separation using potentials computed via lattice QCD in the limit of static anti-bottom quarks. This coupled Schr\"odinger equation allows to incorporate effects due to the heavy anti-bottom spins. First exploratory numerical tests are discussed.
[ { "created": "Wed, 13 May 2015 18:57:54 GMT", "version": "v1" } ]
2015-05-14
[ [ "Scheunert", "Jonas", "" ], [ "Bicudo", "Pedro", "" ], [ "Uenver", "Annabelle", "" ], [ "Wagner", "Marc", "" ] ]
We investigate four-quark systems consisting of two heavy anti-bottom quarks and two light up/down quarks. We propose to solve a coupled Schr\"odinger equation for the anti-bottom-anti-bottom separation using potentials computed via lattice QCD in the limit of static anti-bottom quarks. This coupled Schr\"odinger equation allows to incorporate effects due to the heavy anti-bottom spins. First exploratory numerical tests are discussed.
hep-ph/9502224
null
M.B. Voloshin
Precision determination of $\alpha_s$ and $m_b$ from QCD sum rules for $b \overline b$.
15 pages + 4 figures in LaTeX (FEYNMAN macros used for Fig.3)
Int.J.Mod.Phys. A10 (1995) 2865-2880
10.1142/S0217751X95001364
TPI-MINN-95/1-T, UMN-TH-1326-95
hep-ph
null
The QCD sum rules for moments of production cross section of $b \overline b$ states in $e^+\,e^-$ annihilation are extremely sensitive to the values of $m_b$ and $\alpha_s$ for moments of large order $n$. This enables one to extract from the existing data on $\Upsilon$ resonances the values of these parameters with a high precision by using a non-relativistic expansion in $1/n$. It is found that the sum rules fit the data with $\alpha_s^{\overline {MS}} (1 \, GeV) = 0.336 \pm 0.011$ and $m_b=4827 \pm 7 MeV$, where the estimate of the errors includes the theoretical uncertainty due to subleading in $1/n$ terms and the experimental uncertainty of the $e^+\,e^-$ annihilation cross section above the $B \overline B$ threshold. The found value of $\alpha_s$, when evolved in two loops up to the $Z$ mass, gives $\alpha_s^{\overline {MS}} (M_Z) = 0.109 \pm 0.001$. The $b$ quark mass $m_b$ corresponds to the `on shell' value appropriate for one-loop perturbative calculations.
[ { "created": "Sat, 4 Feb 1995 18:41:28 GMT", "version": "v1" } ]
2015-06-25
[ [ "Voloshin", "M. B.", "" ] ]
The QCD sum rules for moments of production cross section of $b \overline b$ states in $e^+\,e^-$ annihilation are extremely sensitive to the values of $m_b$ and $\alpha_s$ for moments of large order $n$. This enables one to extract from the existing data on $\Upsilon$ resonances the values of these parameters with a high precision by using a non-relativistic expansion in $1/n$. It is found that the sum rules fit the data with $\alpha_s^{\overline {MS}} (1 \, GeV) = 0.336 \pm 0.011$ and $m_b=4827 \pm 7 MeV$, where the estimate of the errors includes the theoretical uncertainty due to subleading in $1/n$ terms and the experimental uncertainty of the $e^+\,e^-$ annihilation cross section above the $B \overline B$ threshold. The found value of $\alpha_s$, when evolved in two loops up to the $Z$ mass, gives $\alpha_s^{\overline {MS}} (M_Z) = 0.109 \pm 0.001$. The $b$ quark mass $m_b$ corresponds to the `on shell' value appropriate for one-loop perturbative calculations.
1504.07230
Xiaojun Bi
Su-Jie Lin, Xiao-Jun Bi, Peng-Fei Yin, Zhao-Huan Yu
Implications for dark matter annihilation from the AMS-02 $\bar{p}/p$ ratio
15 pages, 4 figures, 3 tables
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The AMS-02 collaboration has just released the cosmic antiproton to proton ratio $\bar{p}/p$ with a high precision up to $\sim 450$ GeV. In this work, we calculate the secondary antiprotons generated by cosmic ray interactions with the interstellar medium taking into account the uncertainties from the cosmic ray propagation. The $\bar{p}/p$ ratio predicted by these processes shows some tension with the AMS-02 data in some regions of propagation parameters, but the excess is not significant. We then try to derive upper bounds on the dark matter annihilation cross section from the $\bar{p}/p$ data or signal regions favored by the data. It is shown that the constraint derived by the AMS-02 data is similar to that from Fermi-LAT observations of dwarf galaxies. The signal region for dark matter is usually required $m_\chi \sim O(10)$ TeV and $\left<\sigma v\right>\sim\mathcal{O}(10^{-23})~\cm^3~\sec^{-1}$.
[ { "created": "Mon, 27 Apr 2015 19:56:27 GMT", "version": "v1" } ]
2015-04-28
[ [ "Lin", "Su-Jie", "" ], [ "Bi", "Xiao-Jun", "" ], [ "Yin", "Peng-Fei", "" ], [ "Yu", "Zhao-Huan", "" ] ]
The AMS-02 collaboration has just released the cosmic antiproton to proton ratio $\bar{p}/p$ with a high precision up to $\sim 450$ GeV. In this work, we calculate the secondary antiprotons generated by cosmic ray interactions with the interstellar medium taking into account the uncertainties from the cosmic ray propagation. The $\bar{p}/p$ ratio predicted by these processes shows some tension with the AMS-02 data in some regions of propagation parameters, but the excess is not significant. We then try to derive upper bounds on the dark matter annihilation cross section from the $\bar{p}/p$ data or signal regions favored by the data. It is shown that the constraint derived by the AMS-02 data is similar to that from Fermi-LAT observations of dwarf galaxies. The signal region for dark matter is usually required $m_\chi \sim O(10)$ TeV and $\left<\sigma v\right>\sim\mathcal{O}(10^{-23})~\cm^3~\sec^{-1}$.
1404.1408
Cheng-Hsien Li
Cheng-Hsien Li and Yong-Zhong Qian
A Pedagogical Discussion on Neutrino Wave-Packet Evolution
submitted to 2013 TAUP Conference Proceedings
Physics Procedia 61 (2015) 724-728
10.1016/j.phpro.2014.12.088
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a pedagogical discussion on the time evolution of a Gaussian neutrino wave packet in free space. A common treatment is to keep momentum terms up to the quadratic order in the expansion of the energy-momentum relation so that the Fourier transform can be evaluated analytically via Gaussian integrals. This leads to a solution representing a flat Gaussian distribution with a constant longitudinal width and a spreading transverse width, which suggests that special relativity would be violated if the neutrino wave packet were detected on its edge. However, we demonstrate that by including terms of higher order in momentum the correct geometry of the wave packet is restored. The corrected solution has a spherical wave front so that it complies with special relativity.
[ { "created": "Fri, 4 Apr 2014 22:59:16 GMT", "version": "v1" } ]
2015-03-27
[ [ "Li", "Cheng-Hsien", "" ], [ "Qian", "Yong-Zhong", "" ] ]
We present a pedagogical discussion on the time evolution of a Gaussian neutrino wave packet in free space. A common treatment is to keep momentum terms up to the quadratic order in the expansion of the energy-momentum relation so that the Fourier transform can be evaluated analytically via Gaussian integrals. This leads to a solution representing a flat Gaussian distribution with a constant longitudinal width and a spreading transverse width, which suggests that special relativity would be violated if the neutrino wave packet were detected on its edge. However, we demonstrate that by including terms of higher order in momentum the correct geometry of the wave packet is restored. The corrected solution has a spherical wave front so that it complies with special relativity.
1811.11230
Imrich Zborovsky
I. Zborovsk\'y
Three-component multiplicity distribution, oscillation of combinants and properties of clans in $pp$ collisions at the LHC
24 pages, 21 figures
Eur. Phys. J. C (2018) 78:816
10.1140/epjc/s10052-018-6287-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multiplicity distributions of charged particles measured by the ATLAS Collaboration in proton-proton collisions at $\sqrt{s}=8$ and 13 TeV are analyzed in the framework of a weighted superposition of three negative binomial distribution functions. The examination of the experimental data confirms the existence of a narrow peak at low multiplicities found earlier at $\sqrt{s}=0.9$ and 7 TeV. The peak is described by the third separate component of the total distribution. The energy dependence of the multiplicity characteristics of the three-component scenario is studied. It is demonstrated that the third multiplicity component might be responsible for oscillations of combinants observed lately in the analysis of the multiplicity distributions measured in proton-proton collisions at the LHC. Some consequences of the three-component description of the data for the clan parameters are analyzed.
[ { "created": "Tue, 27 Nov 2018 19:56:08 GMT", "version": "v1" } ]
2018-11-29
[ [ "Zborovský", "I.", "" ] ]
Multiplicity distributions of charged particles measured by the ATLAS Collaboration in proton-proton collisions at $\sqrt{s}=8$ and 13 TeV are analyzed in the framework of a weighted superposition of three negative binomial distribution functions. The examination of the experimental data confirms the existence of a narrow peak at low multiplicities found earlier at $\sqrt{s}=0.9$ and 7 TeV. The peak is described by the third separate component of the total distribution. The energy dependence of the multiplicity characteristics of the three-component scenario is studied. It is demonstrated that the third multiplicity component might be responsible for oscillations of combinants observed lately in the analysis of the multiplicity distributions measured in proton-proton collisions at the LHC. Some consequences of the three-component description of the data for the clan parameters are analyzed.
2308.05691
Junichiro Kawamura
Waleed Abdallah, Mustafa Ashry, Junichiro Kawamura and Ahmad Moursy
Semi-visible dark photon in a model with vector-like leptons for the $(g-2)_{e,\mu}$ and $W$-boson mass anomalies
20 pages, 3 figures, 2 tables; ver2 matched to published version
null
10.1103/PhysRevD.109.015031
CTPU-PTC-23-32
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We propose a model realizes that a semi-visible dark photon which can contribute to the anomalous magnetic moment ($g-2$) of both electron and muon. In this model, the electron $g-2$ is deviated from the Standard Model (SM) prediction by the 1-loop diagrams involving the vector-like leptons, while that of muon is deviated due to a non-vanishing gauge kinetic mixing with photons. We also argue that the $W$-boson mass can be deviated from the SM prediction due to the vector-like lepton loops, so that the value obtained by the CDF II experiment can be explained. Thus, this model simultaneously explains the recent three anomalies in $g-2$ of electron and muon as well as the $W$-boson mass. The constraints on the $\mathcal{O}(1)~\mathrm{GeV}$ dark photon can be avoided because of the semi-invisible decay of the dark photon, $A^\prime \to 2 N \to 2\nu \,2\chi \to 2\nu \,4e$, where $N$ is a SM singlet vector-like neutrino and $\chi$ is a CP-even Higgs boson of the $U(1)^\prime$ gauge symmetry.
[ { "created": "Thu, 10 Aug 2023 16:46:57 GMT", "version": "v1" }, { "created": "Thu, 1 Feb 2024 02:57:04 GMT", "version": "v2" } ]
2024-02-02
[ [ "Abdallah", "Waleed", "" ], [ "Ashry", "Mustafa", "" ], [ "Kawamura", "Junichiro", "" ], [ "Moursy", "Ahmad", "" ] ]
We propose a model realizes that a semi-visible dark photon which can contribute to the anomalous magnetic moment ($g-2$) of both electron and muon. In this model, the electron $g-2$ is deviated from the Standard Model (SM) prediction by the 1-loop diagrams involving the vector-like leptons, while that of muon is deviated due to a non-vanishing gauge kinetic mixing with photons. We also argue that the $W$-boson mass can be deviated from the SM prediction due to the vector-like lepton loops, so that the value obtained by the CDF II experiment can be explained. Thus, this model simultaneously explains the recent three anomalies in $g-2$ of electron and muon as well as the $W$-boson mass. The constraints on the $\mathcal{O}(1)~\mathrm{GeV}$ dark photon can be avoided because of the semi-invisible decay of the dark photon, $A^\prime \to 2 N \to 2\nu \,2\chi \to 2\nu \,4e$, where $N$ is a SM singlet vector-like neutrino and $\chi$ is a CP-even Higgs boson of the $U(1)^\prime$ gauge symmetry.
hep-ph/9905304
Sasa Prelovsek
S. Prelovsek, S. Fajfer and P. Singer
Probing $c\to u\gamma$ in $B_c\to B_u^*\gamma$ decay
5 pages, Talk presented at XXXIV Recontres de Moriond on 'Electroweak interactions and unified theories', Les Arcs, 13-20.3.1999
null
null
IJS-TP-99/10
hep-ph
null
Flavour changing neutral current (FCNC) transitions $c\to u\gamma$ and $c\to ul^+l^-$ are very rare in the standard model and present an interesting probe for the physics beyond it. We study long distance contamination to these short distance processes in different hadron decays. As the most suitable probe for $c\to u\gamma$ transition we propose $B_c\to B_u^*\gamma$ decay. Its detection at the branching ratio well above $10^{-8}$ would signal new physics. The $c\to ul^+l^-$ transition may be probed at high $m_{ll}$ in $D\to \pi l^+l^-$. The decays $D\to V\gamma$ and $D\to Vl^+l^-$ ($V$ is a light vector meson) are less suitable, since they are dominated by the long distance effects.
[ { "created": "Tue, 11 May 1999 12:58:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Prelovsek", "S.", "" ], [ "Fajfer", "S.", "" ], [ "Singer", "P.", "" ] ]
Flavour changing neutral current (FCNC) transitions $c\to u\gamma$ and $c\to ul^+l^-$ are very rare in the standard model and present an interesting probe for the physics beyond it. We study long distance contamination to these short distance processes in different hadron decays. As the most suitable probe for $c\to u\gamma$ transition we propose $B_c\to B_u^*\gamma$ decay. Its detection at the branching ratio well above $10^{-8}$ would signal new physics. The $c\to ul^+l^-$ transition may be probed at high $m_{ll}$ in $D\to \pi l^+l^-$. The decays $D\to V\gamma$ and $D\to Vl^+l^-$ ($V$ is a light vector meson) are less suitable, since they are dominated by the long distance effects.
hep-ph/0610220
Alfonso Rosado
A. Rosado
Effects of charged Higgs bosons in the deep inelastic process \nu_{\tau} {\cal N} \to \tau^- X and the possibility of detecting tau-neutrinos at cosmic neutrino detectors
18 pages, 2 figures, 8 tables
Pramana70:603-615,2008
10.1007/s12043-008-0022-3
null
hep-ph
null
We study the deep inelastic process $\nu_{\tau} + {\cal N} \to \tau^{-} + X$ (with ${\cal N} \equiv (n+p)/2$ an isoscalar nucleon), in the context of the two Higgs doublet model type II (2HDM(II)). We discuss the contribution to the total cross section of diagrams, in which a charged Higgs boson is exchanged. We present results which show the strong dependence of such contribution on $\tan\beta$ and $M_{H^{\pm}}$. We show that in the region $50 \leq \tan\beta \leq 200$ and 90 GeV $\leq M_{H^{\pm}}\leq$ 600 GeV with the additional experimental constraint on the involved model parameters $M_{H^{\pm}} \geq 1.5 \times \tan\beta$ GeV, the contribution of the charged Higgs boson exchange diagrams to the cross section of the charged current inclusive $\nu_{\tau} {\cal N}$ collision can become important. We obtain that this contribution for an inclusive dispersion generated through the collision of an ultrahigh energy tau-neutrino with $E_{\nu} \approx 10^{20}$ eV on a target nucleon can be larger than the value of the contribution of the $W^{\pm}$ exchange diagrams, provided that $M_{H^{\pm}} \approx 300$ GeV and $\tan\beta \approx 200$. Such enhancement and the induced variation on the mean inelasticity $<y >^{CC}$ could lead to sizeable effects in the acceptance of cosmic tau-neutrino detectors at experiments such as HiRes, PAO, and the CRTNT, which are anchored to the ground, and at experiments such as EUSO and OWL, which are proposed to orbit around the Earth.
[ { "created": "Tue, 17 Oct 2006 22:46:07 GMT", "version": "v1" }, { "created": "Thu, 6 Sep 2007 00:34:36 GMT", "version": "v2" } ]
2008-11-26
[ [ "Rosado", "A.", "" ] ]
We study the deep inelastic process $\nu_{\tau} + {\cal N} \to \tau^{-} + X$ (with ${\cal N} \equiv (n+p)/2$ an isoscalar nucleon), in the context of the two Higgs doublet model type II (2HDM(II)). We discuss the contribution to the total cross section of diagrams, in which a charged Higgs boson is exchanged. We present results which show the strong dependence of such contribution on $\tan\beta$ and $M_{H^{\pm}}$. We show that in the region $50 \leq \tan\beta \leq 200$ and 90 GeV $\leq M_{H^{\pm}}\leq$ 600 GeV with the additional experimental constraint on the involved model parameters $M_{H^{\pm}} \geq 1.5 \times \tan\beta$ GeV, the contribution of the charged Higgs boson exchange diagrams to the cross section of the charged current inclusive $\nu_{\tau} {\cal N}$ collision can become important. We obtain that this contribution for an inclusive dispersion generated through the collision of an ultrahigh energy tau-neutrino with $E_{\nu} \approx 10^{20}$ eV on a target nucleon can be larger than the value of the contribution of the $W^{\pm}$ exchange diagrams, provided that $M_{H^{\pm}} \approx 300$ GeV and $\tan\beta \approx 200$. Such enhancement and the induced variation on the mean inelasticity $<y >^{CC}$ could lead to sizeable effects in the acceptance of cosmic tau-neutrino detectors at experiments such as HiRes, PAO, and the CRTNT, which are anchored to the ground, and at experiments such as EUSO and OWL, which are proposed to orbit around the Earth.
2301.07975
Aleksei Nikolskii
I. P. Lokhtin, A. V. Nikolskii, A. M. Snigirev
On geometrical interpretation of alignment phenomenon
8 pages, 5 figures, the additional investigations done for the different types of region symmetry. Version accepted for publication in Eur. Phys. J. C
Eur.Phys.J.C 83 (2023) 4, 324
10.1140/epjc/s10052-023-11528-5
null
hep-ph astro-ph.HE hep-ex
http://creativecommons.org/licenses/by/4.0/
The observed alignment of spots in the x-ray films in cosmic ray emulsion experiments is analyzed and interpreted in the framework of geometrical approach. It is shown that the high degree of alignment can appear partly due to the selection procedure of most energetic particles itself and the threshold on the energy deposition together with the transverse momentum conservation.
[ { "created": "Thu, 19 Jan 2023 10:11:18 GMT", "version": "v1" }, { "created": "Tue, 18 Apr 2023 19:39:00 GMT", "version": "v2" } ]
2023-05-02
[ [ "Lokhtin", "I. P.", "" ], [ "Nikolskii", "A. V.", "" ], [ "Snigirev", "A. M.", "" ] ]
The observed alignment of spots in the x-ray films in cosmic ray emulsion experiments is analyzed and interpreted in the framework of geometrical approach. It is shown that the high degree of alignment can appear partly due to the selection procedure of most energetic particles itself and the threshold on the energy deposition together with the transverse momentum conservation.
hep-ph/0409146
Paolo Nason
Paolo Nason
A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
29 pages, 6 figures
JHEP 0411:040,2004
10.1088/1126-6708/2004/11/040
Bicocca-FT-04-11
hep-ph
null
I show that with simple extensions of the shower algorithms in Monte Carlo programs, one can implement NLO corrections to the hardest emission that overcome the problems of negative weighted events found in previous implementations. Simple variants of the same method can be used for an improved treatment of matrix element corrections in Shower Monte Carlo programs.
[ { "created": "Mon, 13 Sep 2004 15:09:18 GMT", "version": "v1" } ]
2011-05-05
[ [ "Nason", "Paolo", "" ] ]
I show that with simple extensions of the shower algorithms in Monte Carlo programs, one can implement NLO corrections to the hardest emission that overcome the problems of negative weighted events found in previous implementations. Simple variants of the same method can be used for an improved treatment of matrix element corrections in Shower Monte Carlo programs.
1003.4696
Passemar Emilie
Emilie Passemar
Precision SM calculations and theoretical interests beyond the SM in K_{l2} and K_{l3} decays
14 pages, 5 figures, Invited talk given at the KAON09 International Conference, June 9-12 2009, Tsukuba, Japan
PoS(KAON09)024,2009
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a brief overview of the recent theoretical progress to describe the K_{l2} and K_{l3} decays. We discuss the interesting probes of the Standard Model offered by these decays such as the extraction of |V_{us}| and the test of the CKM unitarity, the tests of lepton universality, the quark mass ratio determination and the test of the electroweak couplings of the light quarks to the W-boson.
[ { "created": "Wed, 24 Mar 2010 17:14:14 GMT", "version": "v1" } ]
2010-03-25
[ [ "Passemar", "Emilie", "" ] ]
We present a brief overview of the recent theoretical progress to describe the K_{l2} and K_{l3} decays. We discuss the interesting probes of the Standard Model offered by these decays such as the extraction of |V_{us}| and the test of the CKM unitarity, the tests of lepton universality, the quark mass ratio determination and the test of the electroweak couplings of the light quarks to the W-boson.
hep-ph/9705278
Erasmo Ferreira
Erasmo Ferreira (Universidade Federal do Rio de Janeiro) and Fl\'avio Pereira (Observat\'orio Nacional, CNPq, Rio de Janeiro)
Hadronic sizes and observables in high-energy scattering
Latex, using Revtex.style . 2 ps figures. To be published in Physical Review D , July 1997
Phys.Rev. D56 (1997) 179-183
10.1103/PhysRevD.56.179
null
hep-ph
null
The functional dependence of the high-energy observables of total cross section and slope parameter on the sizes of the colliding hadrons predicted by the model of the stochastic vacuum and the corresponding relations used in the geometric model of Povh and H\"ufner are confronted with the experimental data. The existence of a universal term in the expression for the slope, due purely to vacuum effects, independent of the energy and of the particular hadronic system, is investigated. Accounting for the two independent correlation functions of the QCD vacuum, we improve the simple and consistent description given by the model of the stochastic vacuum to the high-energy pp and pbar-p data, with a new determination of parameters of non-perturbative QCD. The increase of the hadronic radii with the energy accounts for the energy dependence of the observables.
[ { "created": "Fri, 9 May 1997 17:05:59 GMT", "version": "v1" } ]
2009-10-30
[ [ "Ferreira", "Erasmo", "", "Universidade Federal do Rio de Janeiro" ], [ "Pereira", "Flávio", "", "Observatório Nacional, CNPq, Rio de Janeiro" ] ]
The functional dependence of the high-energy observables of total cross section and slope parameter on the sizes of the colliding hadrons predicted by the model of the stochastic vacuum and the corresponding relations used in the geometric model of Povh and H\"ufner are confronted with the experimental data. The existence of a universal term in the expression for the slope, due purely to vacuum effects, independent of the energy and of the particular hadronic system, is investigated. Accounting for the two independent correlation functions of the QCD vacuum, we improve the simple and consistent description given by the model of the stochastic vacuum to the high-energy pp and pbar-p data, with a new determination of parameters of non-perturbative QCD. The increase of the hadronic radii with the energy accounts for the energy dependence of the observables.
hep-ph/9903235
Stephen Wong
J.I. Kapusta and S.M.H. Wong
Imaging the Space-Time Evolution of High Energy Nucleus-Nucleus Collisions with Bremsstrahlung
9 pages revtex style, 9 embedded PS figures
Phys.Rev. C59 (1999) 3317
10.1103/PhysRevC.59.3317
NUC-MINN-99/3-T
hep-ph nucl-th
null
The bremsstrahlung produced when heavy nuclei collide is estimated for central collisions at the Relativistic Heavy Ion Collider. Bremsstrahlung photons with energies below 100 to 200 MeV are sufficient to discern the gross features of the space-time evolution of electric charge, if they can be separated from other sources of photons experimentally. This is illustrated explicitly by considering two very different models, one Bjorken-like, the other Landau-like, both of which are constructed to give the same final charge rapidity distribution.
[ { "created": "Tue, 2 Mar 1999 22:38:02 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kapusta", "J. I.", "" ], [ "Wong", "S. M. H.", "" ] ]
The bremsstrahlung produced when heavy nuclei collide is estimated for central collisions at the Relativistic Heavy Ion Collider. Bremsstrahlung photons with energies below 100 to 200 MeV are sufficient to discern the gross features of the space-time evolution of electric charge, if they can be separated from other sources of photons experimentally. This is illustrated explicitly by considering two very different models, one Bjorken-like, the other Landau-like, both of which are constructed to give the same final charge rapidity distribution.
1912.02536
Johannes Bl\"umlein
J. Ablinger, A. Behring, J. Bl\"umlein, A. De Freitas, A. von Manteuffel, C. Schneider and K. Sch\"onwald
The three-loop single mass polarized pure singlet operator matrix element
25 pages Latex, 2 Figures
null
10.1016/j.nuclphysb.2020.114945
DESY 19--216, DO--TH 19/02, TTP 19--043, MSUHEP-19-026, SAGEX 19-30
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the massive polarized three-loop pure singlet operator matrix element $A_{Qq}^{(3), \rm PS}$ in the single mass case in the Larin scheme. This operator matrix element contributes to the massive polarized three-loop Wilson coefficient $H_{Qq}^{(3),\rm PS}$ in deep-inelastic scattering and constitutes a three-loop transition matrix element in the variable flavor number scheme. We provide analytic results in Mellin $N$ and in $x$ space and study the behaviour of this operator matrix element in the region of small and large values of the Bjorken variable $x$.
[ { "created": "Thu, 5 Dec 2019 12:35:33 GMT", "version": "v1" } ]
2020-02-12
[ [ "Ablinger", "J.", "" ], [ "Behring", "A.", "" ], [ "Blümlein", "J.", "" ], [ "De Freitas", "A.", "" ], [ "von Manteuffel", "A.", "" ], [ "Schneider", "C.", "" ], [ "Schönwald", "K.", "" ] ]
We calculate the massive polarized three-loop pure singlet operator matrix element $A_{Qq}^{(3), \rm PS}$ in the single mass case in the Larin scheme. This operator matrix element contributes to the massive polarized three-loop Wilson coefficient $H_{Qq}^{(3),\rm PS}$ in deep-inelastic scattering and constitutes a three-loop transition matrix element in the variable flavor number scheme. We provide analytic results in Mellin $N$ and in $x$ space and study the behaviour of this operator matrix element in the region of small and large values of the Bjorken variable $x$.
2101.06472
Manoranjan Dutta
Manoranjan Dutta (1), Satyabrata Mahapatra (1), Debasish Borah (2), Narendra Sahu (1) ((1) Indian Institute of Technology Hyderabad, (2) Indian Institute of Technology Guwahati)
Self-interacting Inelastic Dark Matter in the light of XENON1T excess
34 pages, 14 figures, version accepted for publication in PRD
Phys. Rev. D 103, 095018 (2021)
10.1103/PhysRevD.103.095018
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a self-interacting inelastic dark matter (DM) scenario as a possible origin of the recently reported excess of electron recoil events by the XENON1T experiment. Two quasi-degenerate Majorana fermion DM interact within themselves via a light hidden sector massive gauge boson and with the standard model particles via gauge kinetic mixing. We also consider an additional long-lived singlet scalar which helps in realising correct dark matter relic abundance via a hybrid setup comprising of both freeze-in and freeze-out mechanisms. While being consistent with the required DM phenomenology along with sufficient self-interactions to address the small scale issues of cold dark matter, the model with GeV scale DM can explain the XENON1T excess via inelastic down scattering of heavier DM component into the lighter one. All these requirements leave a very tiny parameter space keeping the model very predictive for near future experiments.
[ { "created": "Sat, 16 Jan 2021 16:36:54 GMT", "version": "v1" }, { "created": "Sat, 1 May 2021 00:39:06 GMT", "version": "v2" } ]
2021-05-26
[ [ "Dutta", "Manoranjan", "" ], [ "Mahapatra", "Satyabrata", "" ], [ "Borah", "Debasish", "" ], [ "Sahu", "Narendra", "" ] ]
We propose a self-interacting inelastic dark matter (DM) scenario as a possible origin of the recently reported excess of electron recoil events by the XENON1T experiment. Two quasi-degenerate Majorana fermion DM interact within themselves via a light hidden sector massive gauge boson and with the standard model particles via gauge kinetic mixing. We also consider an additional long-lived singlet scalar which helps in realising correct dark matter relic abundance via a hybrid setup comprising of both freeze-in and freeze-out mechanisms. While being consistent with the required DM phenomenology along with sufficient self-interactions to address the small scale issues of cold dark matter, the model with GeV scale DM can explain the XENON1T excess via inelastic down scattering of heavier DM component into the lighter one. All these requirements leave a very tiny parameter space keeping the model very predictive for near future experiments.
hep-ph/9910277
Haruhiko Terao
Jisuke Kubo (Kanazawa U.), Haruhiko Terao (Kanazawa U.), George Zoupanos (NTUA and Kanazawa U.)
Kaluza-Klein Thresholds and Regularization (In)dependence
39 pages, 12 figures uses epsf.sty
Nucl.Phys.B574:495-524,2000
10.1016/S0550-3213(00)00020-1
KANAZAWA-99-23
hep-ph hep-th
null
We present a method to control the regularization scheme dependence in the running of couplings in Kaluza-Klein theories. Specifically we consider the scalar theory in five dimensions, assuming that one dimension is compactified and we study various regularization schemes in order to analyze concretely the regularization scheme dependence of the Kaluza-Klein threshold effects. We find that in one-loop order, although the $\beta$-functions are different for the different schemes, the net difference in the running of the coupling among the different schemes is very small for the entire range of energies. Our results have been extended to include more than one radii, and the gauge coupling unification is re-examined. Strings are also used as a regulator. We obtain a particular regularization of effective field theory which can accurately describe the string Kaluza-Klein threshold effects.
[ { "created": "Fri, 8 Oct 1999 10:38:13 GMT", "version": "v1" } ]
2014-11-17
[ [ "Kubo", "Jisuke", "", "Kanazawa U." ], [ "Terao", "Haruhiko", "", "Kanazawa U." ], [ "Zoupanos", "George", "", "NTUA and Kanazawa U." ] ]
We present a method to control the regularization scheme dependence in the running of couplings in Kaluza-Klein theories. Specifically we consider the scalar theory in five dimensions, assuming that one dimension is compactified and we study various regularization schemes in order to analyze concretely the regularization scheme dependence of the Kaluza-Klein threshold effects. We find that in one-loop order, although the $\beta$-functions are different for the different schemes, the net difference in the running of the coupling among the different schemes is very small for the entire range of energies. Our results have been extended to include more than one radii, and the gauge coupling unification is re-examined. Strings are also used as a regulator. We obtain a particular regularization of effective field theory which can accurately describe the string Kaluza-Klein threshold effects.
hep-ph/0404126
Markus Eidemuller
Markus Eidemuller
Pentaquark and diquark-diquark clustering: a QCD sum rule approach
10 pages, 3 figures; discussions extended, references added, version to appear in Phys. Lett. B
Phys.Lett. B597 (2004) 314-320
10.1016/j.physletb.2004.07.029
IFIC/04-15
hep-ph
null
In this work we study the Theta(1540) in the framework of QCD sum rules based on (ud)^2\bar{s} diquark clustering as suggested by Jaffe and Wilczek. Within errors, the mass of the pentaquark is compatible with the experimentally measured value. The mass difference between the Theta and the pentaquark with the quantum numbers of the nucleon amounts to 70 MeV, consistent with the interpretation of the N(1440) as a pentaquark.
[ { "created": "Thu, 15 Apr 2004 14:17:07 GMT", "version": "v1" }, { "created": "Wed, 21 Apr 2004 13:30:38 GMT", "version": "v2" }, { "created": "Tue, 27 Jul 2004 14:04:32 GMT", "version": "v3" } ]
2009-11-10
[ [ "Eidemuller", "Markus", "" ] ]
In this work we study the Theta(1540) in the framework of QCD sum rules based on (ud)^2\bar{s} diquark clustering as suggested by Jaffe and Wilczek. Within errors, the mass of the pentaquark is compatible with the experimentally measured value. The mass difference between the Theta and the pentaquark with the quantum numbers of the nucleon amounts to 70 MeV, consistent with the interpretation of the N(1440) as a pentaquark.
hep-ph/0305216
Viktor Nikonov
A.V. Anisovich, V.V. Anisovich, V.A. Nikonov
Radiative decays of mesons in the quark model: relativistic and non-relativistic approaches
11 pages, Latex, 1 figure, We have extended the discussion of analytical properties of the amplitude
null
null
null
hep-ph
null
Different conclusions about quark nature of f0(980) based on the analysis of data on the reaction phi(1020) -> gamma f0(980) make it necessary to perform detailed comparison of formulae used by various groups for the calculation of partial widths of radiative decays. We carry out a comparative analysis of methods of calculation of radiative decays like phi -> gamma f0 and phi -> gamma eta performed by F.E.Close et al., Phys. Rev. D 65, 092003 (2002), and A.V.Anisovich et al., Eur. Phys. J. A 12, 103 (2001); Yad. Fiz. 65, 523 (2002).
[ { "created": "Tue, 20 May 2003 10:48:15 GMT", "version": "v1" }, { "created": "Fri, 30 Jan 2004 08:05:09 GMT", "version": "v2" } ]
2007-05-23
[ [ "Anisovich", "A. V.", "" ], [ "Anisovich", "V. V.", "" ], [ "Nikonov", "V. A.", "" ] ]
Different conclusions about quark nature of f0(980) based on the analysis of data on the reaction phi(1020) -> gamma f0(980) make it necessary to perform detailed comparison of formulae used by various groups for the calculation of partial widths of radiative decays. We carry out a comparative analysis of methods of calculation of radiative decays like phi -> gamma f0 and phi -> gamma eta performed by F.E.Close et al., Phys. Rev. D 65, 092003 (2002), and A.V.Anisovich et al., Eur. Phys. J. A 12, 103 (2001); Yad. Fiz. 65, 523 (2002).
1912.01275
Marcel Vos
Mar\c{c}a Boronat and Esteban Fullana and Juan Fuster and Pablo Gomis and Andr\'e Hoang and Vicent Mateu and Marcel Vos and Angelika Widl
Top quark mass measurement in radiative events at electron-positron colliders
10 pages + bibliography
null
10.1016/j.physletb.2020.135353
CLICdp-PUB-2019-005, IFIC-19-036, IFT-UAM/CSIC-19-122, UWThPh 2019-26
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this letter, we evaluate potential of linear $e^+e^-$ colliders to measure the top quark mass in radiative events and in a suitable short-distance scheme. We present a calculation of the differential cross section for production of a top quark pair in association with an energetic photon from initial state radiation, as a function of the invariant mass of the $t\bar{t}$ system. This {\it matched} calculation includes the QCD enhancement of the cross section around the $t\bar{t}$ production threshold and remains valid in the continuum well above the threshold. The uncertainty in the top mass determination is evaluated in realistic operating scenarios for the Compact Linear Collider (CLIC) and the International Linear Collider (ILC), including the statistical uncertainty and the theoretical and experimental systematic uncertainties. With this method, the top quark mass can be determined with a precision of $110$ MeV in the initial stage of CLIC, with $1$ ab$^{-1}$ at $\sqrt{s} =$ 380 GeV, and with a precision of approximately $150$ MeV at the ILC, with $L = 4$ ab$^{-1}$ at $\sqrt{s}= 500$ GeV. Radiative events allow measurements of the top quark mass at different renormalization scales, and we demonstrate that such a measurement can yield a statistically significant test of the evolution of the MSR mass $m_t^{\rm MSR}(R)$ for scales $R< m_t$.
[ { "created": "Tue, 3 Dec 2019 10:10:29 GMT", "version": "v1" } ]
2020-03-11
[ [ "Boronat", "Marça", "" ], [ "Fullana", "Esteban", "" ], [ "Fuster", "Juan", "" ], [ "Gomis", "Pablo", "" ], [ "Hoang", "André", "" ], [ "Mateu", "Vicent", "" ], [ "Vos", "Marcel", "" ], [ "Widl", "Angelika", "" ] ]
In this letter, we evaluate potential of linear $e^+e^-$ colliders to measure the top quark mass in radiative events and in a suitable short-distance scheme. We present a calculation of the differential cross section for production of a top quark pair in association with an energetic photon from initial state radiation, as a function of the invariant mass of the $t\bar{t}$ system. This {\it matched} calculation includes the QCD enhancement of the cross section around the $t\bar{t}$ production threshold and remains valid in the continuum well above the threshold. The uncertainty in the top mass determination is evaluated in realistic operating scenarios for the Compact Linear Collider (CLIC) and the International Linear Collider (ILC), including the statistical uncertainty and the theoretical and experimental systematic uncertainties. With this method, the top quark mass can be determined with a precision of $110$ MeV in the initial stage of CLIC, with $1$ ab$^{-1}$ at $\sqrt{s} =$ 380 GeV, and with a precision of approximately $150$ MeV at the ILC, with $L = 4$ ab$^{-1}$ at $\sqrt{s}= 500$ GeV. Radiative events allow measurements of the top quark mass at different renormalization scales, and we demonstrate that such a measurement can yield a statistically significant test of the evolution of the MSR mass $m_t^{\rm MSR}(R)$ for scales $R< m_t$.
1001.5261
Lisa L. Everett
Baris Altunkaynak, Lisa L. Everett, Ian-Woo Kim, Brent D. Nelson, and Yongyan Rao
Phenomenological Implications of Deflected Mirage Mediation: Comparison with Mirage Mediation
29 pages, 9 figures
JHEP 1005:054,2010
10.1007/JHEP05(2010)054
MADPH-10-1553
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compare the collider phenomenology of mirage mediation and deflected mirage mediation, which are two recently proposed "mixed" supersymmetry breaking scenarios motivated from string compactifications. The scenarios differ in that deflected mirage mediation includes contributions from gauge mediation in addition to the contributions from gravity mediation and anomaly mediation also present in mirage mediation. The threshold effects from gauge mediation can drastically alter the low energy spectrum from that of pure mirage mediation models, resulting in some cases in a squeezed gaugino spectrum and a gluino that is much lighter than other colored superpartners. We provide several benchmark deflected mirage mediation models and construct model lines as a function of the gauge mediation contributions, and discuss their discovery potential at the LHC.
[ { "created": "Thu, 28 Jan 2010 20:39:41 GMT", "version": "v1" } ]
2014-11-20
[ [ "Altunkaynak", "Baris", "" ], [ "Everett", "Lisa L.", "" ], [ "Kim", "Ian-Woo", "" ], [ "Nelson", "Brent D.", "" ], [ "Rao", "Yongyan", "" ] ]
We compare the collider phenomenology of mirage mediation and deflected mirage mediation, which are two recently proposed "mixed" supersymmetry breaking scenarios motivated from string compactifications. The scenarios differ in that deflected mirage mediation includes contributions from gauge mediation in addition to the contributions from gravity mediation and anomaly mediation also present in mirage mediation. The threshold effects from gauge mediation can drastically alter the low energy spectrum from that of pure mirage mediation models, resulting in some cases in a squeezed gaugino spectrum and a gluino that is much lighter than other colored superpartners. We provide several benchmark deflected mirage mediation models and construct model lines as a function of the gauge mediation contributions, and discuss their discovery potential at the LHC.
hep-ph/9812521
Fred Jegerlehner
S. Eidelman (BudkerINP, Novosibirsk), F. Jegerlehner (DESY Zeuthen), A.L. Kataev (INR-ASR, Moscow), O. Veretin (DESY Zeuthen)
Testing non-perturbative strong interaction effects via the Adler function
14 pages, 5 figures
Phys.Lett. B454 (1999) 369-380
10.1016/S0370-2693(99)00389-5
DESY 98-206
hep-ph
null
Based on the compilation of the available e^+e^- data, we present a non-perturbative estimation of the Adler function derived from the electromagnetic current correlator, and compare it with theoretical predictions from perturbative QCD (pQCD). The comparison is presented for the Euclidean region where pQCD is supposed to work best. We emphasize that such a comparison only makes sense if one takes into account the exact mass dependence of the perturbative predictions, which are available for the leading and next to leading (two-loop) order. In order to have the correct physical mass dependence in the evolution of the strong coupling as well, we utilize the MOM scheme beta-function to two-loops calculated recently. Three-loop effects, which are available as series expansions for low and high momentum transfer, are included by using Pade improvement. We discuss possible constraints on non-perturbative effects as suggested by the operator product expansion.
[ { "created": "Wed, 30 Dec 1998 23:05:07 GMT", "version": "v1" } ]
2009-10-31
[ [ "Eidelman", "S.", "", "BudkerINP, Novosibirsk" ], [ "Jegerlehner", "F.", "", "DESY Zeuthen" ], [ "Kataev", "A. L.", "", "INR-ASR, Moscow" ], [ "Veretin", "O.", "", "DESY Zeuthen" ] ]
Based on the compilation of the available e^+e^- data, we present a non-perturbative estimation of the Adler function derived from the electromagnetic current correlator, and compare it with theoretical predictions from perturbative QCD (pQCD). The comparison is presented for the Euclidean region where pQCD is supposed to work best. We emphasize that such a comparison only makes sense if one takes into account the exact mass dependence of the perturbative predictions, which are available for the leading and next to leading (two-loop) order. In order to have the correct physical mass dependence in the evolution of the strong coupling as well, we utilize the MOM scheme beta-function to two-loops calculated recently. Three-loop effects, which are available as series expansions for low and high momentum transfer, are included by using Pade improvement. We discuss possible constraints on non-perturbative effects as suggested by the operator product expansion.
2010.06623
Wei-Yang Liu
Wei-Yang Liu, Jiunn-Wei Chen
Renormalon Effects in Quasi Parton Distributions
16 pages, 5 figures
null
10.1103/PhysRevD.104.094501
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the renormalon ambiguity from bubble-chain diagrams in the isovector unpolarized quasi-parton distribution function (PDF) of a hadron. We confirm the assertion by Braun, Vladimirov and Zhang (arXiv:1810.00048) that the leading IR renormalon ambiguity is formally an $\mathcal{O}({\Lambda}^2_{QCD}/x^2P_z^2)$ effect, with $x$ the parton momentum fraction and $P_z$ the hadron momentum, together with a new $\mathcal{O}(\delta(x)\Lambda^2_{QCD}/P_z^2)$ contribution such that the quark number is conserved. This implies the convergence of the perturbative matching kernel between a quasi-PDF and a PDF would eventually fail for small $x$. However, in both the R-scheme designed to cancel the leading IR renormalon and the typically used RI/MOM scheme in lattice QCD for the same quasi-PDF, we find good convergence in the kernel based on three-loop bubble-chain diagram analyses. These results are encouraging for the quasi-PDF program. However, firm conclusions can only be drawn after the complete higher loop QCD calculations are carried out.
[ { "created": "Tue, 13 Oct 2020 18:28:10 GMT", "version": "v1" }, { "created": "Tue, 20 Oct 2020 13:28:33 GMT", "version": "v2" }, { "created": "Thu, 24 Dec 2020 11:30:40 GMT", "version": "v3" }, { "created": "Mon, 28 Dec 2020 03:32:32 GMT", "version": "v4" }, { "created": "Sun, 22 Aug 2021 20:34:33 GMT", "version": "v5" }, { "created": "Mon, 29 Nov 2021 18:30:18 GMT", "version": "v6" } ]
2021-11-30
[ [ "Liu", "Wei-Yang", "" ], [ "Chen", "Jiunn-Wei", "" ] ]
We investigate the renormalon ambiguity from bubble-chain diagrams in the isovector unpolarized quasi-parton distribution function (PDF) of a hadron. We confirm the assertion by Braun, Vladimirov and Zhang (arXiv:1810.00048) that the leading IR renormalon ambiguity is formally an $\mathcal{O}({\Lambda}^2_{QCD}/x^2P_z^2)$ effect, with $x$ the parton momentum fraction and $P_z$ the hadron momentum, together with a new $\mathcal{O}(\delta(x)\Lambda^2_{QCD}/P_z^2)$ contribution such that the quark number is conserved. This implies the convergence of the perturbative matching kernel between a quasi-PDF and a PDF would eventually fail for small $x$. However, in both the R-scheme designed to cancel the leading IR renormalon and the typically used RI/MOM scheme in lattice QCD for the same quasi-PDF, we find good convergence in the kernel based on three-loop bubble-chain diagram analyses. These results are encouraging for the quasi-PDF program. However, firm conclusions can only be drawn after the complete higher loop QCD calculations are carried out.
1504.03260
Sven Heinemeyer
K.J. de Vries, E.A. Bagnaschi, O. Buchmueller, R. Cavanaugh, M. Citron, A. De Roeck, M.J. Dolan, J.R. Ellis, H. Flaecher, S. Heinemeyer, G. Isidori, S. Malik, J. Marrouche, D. Martinez Santos, K.A. Olive, K. Sakurai, G. Weiglein
The pMSSM10 after LHC Run 1
47 pages, 29 figures
null
10.1140/epjc/s10052-015-3599-y
KCL-PH-TH/2015-15, LCTS/2015-07, CERN-PH-TH/2015-066, DESY 15-046, FTPI-MINN-15/13, UMN-TH-3427/15, SLAC-PUB-16245, FERMILAB-PUB-15-100-CMS
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a frequentist analysis of the parameter space of the pMSSM10, in which the following 10 soft SUSY-breaking parameters are specified independently at the mean scalar top mass scale Msusy = Sqrt[M_stop1 M_stop2]: the gaugino masses M_{1,2,3}, the 1st-and 2nd-generation squark masses M_squ1 = M_squ2, the third-generation squark mass M_squ3, a common slepton mass M_slep and a common trilinear mixing parameter A, the Higgs mixing parameter mu, the pseudoscalar Higgs mass M_A and tan beta. We use the MultiNest sampling algorithm with 1.2 x 10^9 points to sample the pMSSM10 parameter space. A dedicated study shows that the sensitivities to strongly-interacting SUSY masses of ATLAS and CMS searches for jets, leptons + MET signals depend only weakly on many of the other pMSSM10 parameters. With the aid of the Atom and Scorpion codes, we also implement the LHC searches for EW-interacting sparticles and light stops, so as to confront the pMSSM10 parameter space with all relevant SUSY searches. In addition, our analysis includes Higgs mass and rate measurements using the HiggsSignals code, SUSY Higgs exclusion bounds, the measurements B-physics observables, EW precision observables, the CDM density and searches for spin-independent DM scattering. We show that the pMSSM10 is able to provide a SUSY interpretation of (g-2)_mu, unlike the CMSSM, NUHM1 and NUHM2. As a result, we find (omitting Higgs rates) that the minimum chi^2/dof = 20.5/18 in the pMSSM10, corresponding to a chi^2 probability of 30.8 %, to be compared with chi^2/dof = 32.8/24 (31.1/23) (30.3/22) in the CMSSM (NUHM1) (NUHM2). We display 1-dimensional likelihood functions for SUSY masses, and show that they may be significantly lighter in the pMSSM10 than in the CMSSM, NUHM1 and NUHM2. We discuss the discovery potential of future LHC runs, e+e- colliders and direct detection experiments.
[ { "created": "Mon, 13 Apr 2015 17:13:28 GMT", "version": "v1" } ]
2015-09-30
[ [ "de Vries", "K. J.", "" ], [ "Bagnaschi", "E. A.", "" ], [ "Buchmueller", "O.", "" ], [ "Cavanaugh", "R.", "" ], [ "Citron", "M.", "" ], [ "De Roeck", "A.", "" ], [ "Dolan", "M. J.", "" ], [ "Ellis", "J. R.", "" ], [ "Flaecher", "H.", "" ], [ "Heinemeyer", "S.", "" ], [ "Isidori", "G.", "" ], [ "Malik", "S.", "" ], [ "Marrouche", "J.", "" ], [ "Santos", "D. Martinez", "" ], [ "Olive", "K. A.", "" ], [ "Sakurai", "K.", "" ], [ "Weiglein", "G.", "" ] ]
We present a frequentist analysis of the parameter space of the pMSSM10, in which the following 10 soft SUSY-breaking parameters are specified independently at the mean scalar top mass scale Msusy = Sqrt[M_stop1 M_stop2]: the gaugino masses M_{1,2,3}, the 1st-and 2nd-generation squark masses M_squ1 = M_squ2, the third-generation squark mass M_squ3, a common slepton mass M_slep and a common trilinear mixing parameter A, the Higgs mixing parameter mu, the pseudoscalar Higgs mass M_A and tan beta. We use the MultiNest sampling algorithm with 1.2 x 10^9 points to sample the pMSSM10 parameter space. A dedicated study shows that the sensitivities to strongly-interacting SUSY masses of ATLAS and CMS searches for jets, leptons + MET signals depend only weakly on many of the other pMSSM10 parameters. With the aid of the Atom and Scorpion codes, we also implement the LHC searches for EW-interacting sparticles and light stops, so as to confront the pMSSM10 parameter space with all relevant SUSY searches. In addition, our analysis includes Higgs mass and rate measurements using the HiggsSignals code, SUSY Higgs exclusion bounds, the measurements B-physics observables, EW precision observables, the CDM density and searches for spin-independent DM scattering. We show that the pMSSM10 is able to provide a SUSY interpretation of (g-2)_mu, unlike the CMSSM, NUHM1 and NUHM2. As a result, we find (omitting Higgs rates) that the minimum chi^2/dof = 20.5/18 in the pMSSM10, corresponding to a chi^2 probability of 30.8 %, to be compared with chi^2/dof = 32.8/24 (31.1/23) (30.3/22) in the CMSSM (NUHM1) (NUHM2). We display 1-dimensional likelihood functions for SUSY masses, and show that they may be significantly lighter in the pMSSM10 than in the CMSSM, NUHM1 and NUHM2. We discuss the discovery potential of future LHC runs, e+e- colliders and direct detection experiments.
1905.00858
Felix Karbstein
Felix Karbstein, Alexander Blinne, Holger Gies, Matt Zepf
Boosting quantum vacuum signatures by coherent harmonic focusing
9 pages, 6 figures; matches journal version; typos corrected
Phys. Rev. Lett. 123, 091802 (2019)
10.1103/PhysRevLett.123.091802
null
hep-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that coherent harmonic focusing provides an efficient mechanism to boost all-optical signatures of quantum vacuum nonlinearity in the collision of high-intensity laser fields, thereby offering a promising route to their first experimental detection. Assuming two laser pulses of given parameters at our disposal, we demonstrate a substantial increase of the number of signal photons measurable in experiments where one of the pulses undergoes coherent harmonic focusing before it collides with the fundamental-frequency pulse. Imposing a quantitative criterion to discern the signal photons from the background of the driving laser photons and accounting for the finite purity of polarization filtering, we find that signal photons arising from inelastic scattering processes constitute a promising signature. By contrast, quasi-elastic contributions which are conventionally assumed to form the most prospective signal remain background dominated. Our findings may result in a paradigm shift concerning which photonic signatures of quantum vacuum nonlinearity are accessible in experiment.
[ { "created": "Thu, 2 May 2019 17:10:09 GMT", "version": "v1" }, { "created": "Sat, 31 Aug 2019 06:59:34 GMT", "version": "v2" }, { "created": "Sat, 25 Jul 2020 13:04:43 GMT", "version": "v3" } ]
2020-07-28
[ [ "Karbstein", "Felix", "" ], [ "Blinne", "Alexander", "" ], [ "Gies", "Holger", "" ], [ "Zepf", "Matt", "" ] ]
We show that coherent harmonic focusing provides an efficient mechanism to boost all-optical signatures of quantum vacuum nonlinearity in the collision of high-intensity laser fields, thereby offering a promising route to their first experimental detection. Assuming two laser pulses of given parameters at our disposal, we demonstrate a substantial increase of the number of signal photons measurable in experiments where one of the pulses undergoes coherent harmonic focusing before it collides with the fundamental-frequency pulse. Imposing a quantitative criterion to discern the signal photons from the background of the driving laser photons and accounting for the finite purity of polarization filtering, we find that signal photons arising from inelastic scattering processes constitute a promising signature. By contrast, quasi-elastic contributions which are conventionally assumed to form the most prospective signal remain background dominated. Our findings may result in a paradigm shift concerning which photonic signatures of quantum vacuum nonlinearity are accessible in experiment.
2402.09331
Howard Georgi
Howard Georgi
Tuning to the Edge of the Abyss in SU(5)
4 pages, 2 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
I show that if a dimensionless parameter is tuned to be close to the boundary of the positivity domain and symmetry breaking is driven by a cubic term in the Lagrangian, the scale of the physics of symmetry breaking in a quantum field theory as measured by the Higgs mass can be much greater than the dimensional scales in the classical Lagrangian. Radiative corrections produce large and physically important corrections, helping to stabilize the large VEV. The resulting picture contrasts sharply with the "modern" view of QFT as an effective field theory. I describe how this mechanism might produce the GUT scale in an SU(5) model in which the dimensional parameters in the Lagrangian are at the low scale.
[ { "created": "Wed, 14 Feb 2024 17:23:15 GMT", "version": "v1" }, { "created": "Tue, 2 Apr 2024 17:57:41 GMT", "version": "v2" }, { "created": "Sat, 27 Apr 2024 21:05:29 GMT", "version": "v3" } ]
2024-04-30
[ [ "Georgi", "Howard", "" ] ]
I show that if a dimensionless parameter is tuned to be close to the boundary of the positivity domain and symmetry breaking is driven by a cubic term in the Lagrangian, the scale of the physics of symmetry breaking in a quantum field theory as measured by the Higgs mass can be much greater than the dimensional scales in the classical Lagrangian. Radiative corrections produce large and physically important corrections, helping to stabilize the large VEV. The resulting picture contrasts sharply with the "modern" view of QFT as an effective field theory. I describe how this mechanism might produce the GUT scale in an SU(5) model in which the dimensional parameters in the Lagrangian are at the low scale.
2308.07169
Jarkko Peuron
Kirill Boguslavski, Aleksi Kurkela, Tuomas Lappi, Florian Lindenbauer, Jarkko Peuron
Heavy quark diffusion coefficient during hydrodynamization -- non-equilibrium vs. equilibrium
6 pages, 5 figures, proceedings for the 11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2023)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the heavy quark momentum diffusion coefficient using effective kinetic theory for a system going through bottom-up isotropization until approximate hydrodynamization. We find that when comparing the nonthermal diffusion coefficient to the thermal one for the same energy density, the observed deviations throughout the whole evolution are within 30% from the thermal value. For thermal systems matched to other quantities we observe considerably larger deviations. We also observe that the diffusion coefficient in the transverse direction dominates at large occupation number, whereas for an underoccupied system the longitudinal diffusion coefficient dominates. Similarly, we study the jet quenching parameter, where we obtain a smooth evolution connecting the large values of the glasma phase with the smaller values in the hydrodynamical regime.
[ { "created": "Mon, 14 Aug 2023 14:24:55 GMT", "version": "v1" } ]
2023-08-15
[ [ "Boguslavski", "Kirill", "" ], [ "Kurkela", "Aleksi", "" ], [ "Lappi", "Tuomas", "" ], [ "Lindenbauer", "Florian", "" ], [ "Peuron", "Jarkko", "" ] ]
We compute the heavy quark momentum diffusion coefficient using effective kinetic theory for a system going through bottom-up isotropization until approximate hydrodynamization. We find that when comparing the nonthermal diffusion coefficient to the thermal one for the same energy density, the observed deviations throughout the whole evolution are within 30% from the thermal value. For thermal systems matched to other quantities we observe considerably larger deviations. We also observe that the diffusion coefficient in the transverse direction dominates at large occupation number, whereas for an underoccupied system the longitudinal diffusion coefficient dominates. Similarly, we study the jet quenching parameter, where we obtain a smooth evolution connecting the large values of the glasma phase with the smaller values in the hydrodynamical regime.
1002.0331
Alexander Kartavtsev
M. Garny, A. Hohenegger, A. Kartavtsev
Medium corrections to the CP-violating parameter in leptogenesis
13 pages, 9 figures
Phys.Rev.D81:085028,2010
10.1103/PhysRevD.81.085028
TUM-HEP-749/10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In two recent papers, arXiv:0909.1559 and arXiv:0911.4122, it has been demonstrated that one can obtain quantum corrected Boltzmann kinetic equations for leptogenesis using a top-down approach based on the Schwinger-Keldysh/Kadanoff-Baym formalism. These "Boltzmann-like" equations are similar to the ones obtained in the conventional bottom-up approach but differ in important details. In particular there is a discrepancy between the CP-violating parameter obtained in the first-principle derivation and in the framework of thermal field theory. Here we demonstrate that the two approaches can be reconciled if causal n-point functions are used in the thermal field theory approach. The new result for the medium correction to the CP-violating parameter is qualitatively different from the conventional one. The analogy to a toy model considered earlier enables us to write down consistent quantum corrected Boltzmann equations for thermal leptogenesis in the Standard Model (supplemented by three right-handed neutrinos) which include quantum statistical terms and medium corrected expressions for the CP-violating parameter.
[ { "created": "Tue, 2 Feb 2010 10:18:36 GMT", "version": "v1" }, { "created": "Mon, 3 May 2010 10:12:50 GMT", "version": "v2" } ]
2010-05-12
[ [ "Garny", "M.", "" ], [ "Hohenegger", "A.", "" ], [ "Kartavtsev", "A.", "" ] ]
In two recent papers, arXiv:0909.1559 and arXiv:0911.4122, it has been demonstrated that one can obtain quantum corrected Boltzmann kinetic equations for leptogenesis using a top-down approach based on the Schwinger-Keldysh/Kadanoff-Baym formalism. These "Boltzmann-like" equations are similar to the ones obtained in the conventional bottom-up approach but differ in important details. In particular there is a discrepancy between the CP-violating parameter obtained in the first-principle derivation and in the framework of thermal field theory. Here we demonstrate that the two approaches can be reconciled if causal n-point functions are used in the thermal field theory approach. The new result for the medium correction to the CP-violating parameter is qualitatively different from the conventional one. The analogy to a toy model considered earlier enables us to write down consistent quantum corrected Boltzmann equations for thermal leptogenesis in the Standard Model (supplemented by three right-handed neutrinos) which include quantum statistical terms and medium corrected expressions for the CP-violating parameter.
1909.05543
Xin-Qiang Li
Feng-Zhi Chen, Xin-Qiang Li, Ya-Dong Yang, and Xin Zhang
CP asymmetry in $\tau\to K_S\pi\nu_\tau$ decays within the Standard Model and beyond
41 pages, 8 figures, and 1 table; more references and discussions added, final version published in the journal
Phys. Rev. D 100, 113006 (2019)
10.1103/PhysRevD.100.113006
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the $2.8\sigma$ discrepancy observed between the BaBar measurement and the Standard Model prediction of the CP asymmetry in $\tau\to K_S\pi\nu_\tau$ decays, as well as the prospects of future measurements at Belle II, we revisit this observable in this paper. Firstly, we reproduce the known CP asymmetry due to $K^0 -\bar{K}^0$ mixing by means of the reciprocal basis, which is convenient when a $K_{S(L)}$ is involved in the final state. As the $K\pi$ tensor form factor plays a crucial role in generating a non-zero direct CP asymmetry that can arise only from the interference of vector and tensor operators, we then present a dispersive representation of this form factor, with its phase obtained in the context of chiral theory with resonances, which fulfills the requirements of unitarity and analyticity. Finally, the $\tau\to K_S\pi\nu_\tau$ decays are analyzed both within a model-independent low-energy effective theory framework and in a scalar leptoquark scenario. It is observed that the CP anomaly can be accommodated in the model-independent framework, even at the $1\sigma$ level, together with the constraint from the branching ratio of $\tau^-\to K_S\pi^-\nu_\tau$ decay; it can be, however, marginally reconciled only at the $2\sigma$ level, due to the specific relation between the scalar and tensor operators in the scalar leptoquark scenario. Once the combined constraints from the branching ratio and the decay spectrum of this decay are taken into account, these possibilities are however both excluded, even without exploiting further the stronger bounds from the (semi-)leptonic kaon decays under the assumption of lepton-flavour universality, as well as from the neutron electric dipole moment and $D-\bar{D}$ mixing under the assumption of $SU(2)$ invariance of the weak interactions.
[ { "created": "Thu, 12 Sep 2019 10:06:32 GMT", "version": "v1" }, { "created": "Tue, 17 Dec 2019 14:36:15 GMT", "version": "v2" } ]
2019-12-25
[ [ "Chen", "Feng-Zhi", "" ], [ "Li", "Xin-Qiang", "" ], [ "Yang", "Ya-Dong", "" ], [ "Zhang", "Xin", "" ] ]
Motivated by the $2.8\sigma$ discrepancy observed between the BaBar measurement and the Standard Model prediction of the CP asymmetry in $\tau\to K_S\pi\nu_\tau$ decays, as well as the prospects of future measurements at Belle II, we revisit this observable in this paper. Firstly, we reproduce the known CP asymmetry due to $K^0 -\bar{K}^0$ mixing by means of the reciprocal basis, which is convenient when a $K_{S(L)}$ is involved in the final state. As the $K\pi$ tensor form factor plays a crucial role in generating a non-zero direct CP asymmetry that can arise only from the interference of vector and tensor operators, we then present a dispersive representation of this form factor, with its phase obtained in the context of chiral theory with resonances, which fulfills the requirements of unitarity and analyticity. Finally, the $\tau\to K_S\pi\nu_\tau$ decays are analyzed both within a model-independent low-energy effective theory framework and in a scalar leptoquark scenario. It is observed that the CP anomaly can be accommodated in the model-independent framework, even at the $1\sigma$ level, together with the constraint from the branching ratio of $\tau^-\to K_S\pi^-\nu_\tau$ decay; it can be, however, marginally reconciled only at the $2\sigma$ level, due to the specific relation between the scalar and tensor operators in the scalar leptoquark scenario. Once the combined constraints from the branching ratio and the decay spectrum of this decay are taken into account, these possibilities are however both excluded, even without exploiting further the stronger bounds from the (semi-)leptonic kaon decays under the assumption of lepton-flavour universality, as well as from the neutron electric dipole moment and $D-\bar{D}$ mixing under the assumption of $SU(2)$ invariance of the weak interactions.
1012.2060
Thomas Gregoire
Tom Brown, Claudia Frugiuele and Thomas Gregoire
UV friendly T-parity in the SU(6)/Sp(6) little Higgs model
21 pages,4 figures. Clarifications added, typos corrected and references added. Published in JHEP
JHEP06(2011)108
10.1007/JHEP06(2011)108
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electroweak precision tests put stringent constraints on the parameter space of little Higgs models. Tree-level exchange of TeV scale particles in a generic little Higgs model produce higher dimensional operators that make contributions to electroweak observables that are typically too large. To avoid this problem a discrete symmetry dubbed T-parity can be introduced to forbid the dangerous couplings. However, it was realized that in simple group models such as the littlest Higgs model, the implementation of T-parity in a UV completion could present some challenges. The situation is analogous to the one in QCD where the pion can easily be defined as being odd under a new $Z_2$ symmetry in the chiral Lagrangian, but this $Z_2$ is not a symmetry of the quark Lagrangian. In this paper we examine the possibility of implementing a T-parity in the low energy $SU(6)/Sp(6)$ model that might be easier to realize in the UV. In our model, the T-parity acts on the low energy non-linear sigma model field in way which is different to what was originally proposed for the Littlest Higgs, and lead to a different low energy theory. In particular, the Higgs sector of this model is a inert two Higgs doublets model with an approximate custodial symmetry. We examine the contributions of the various sectors of the model to electroweak precision data, and to the dark matter abundance.
[ { "created": "Thu, 9 Dec 2010 17:51:49 GMT", "version": "v1" }, { "created": "Fri, 8 Jul 2011 21:06:48 GMT", "version": "v2" } ]
2015-03-17
[ [ "Brown", "Tom", "" ], [ "Frugiuele", "Claudia", "" ], [ "Gregoire", "Thomas", "" ] ]
Electroweak precision tests put stringent constraints on the parameter space of little Higgs models. Tree-level exchange of TeV scale particles in a generic little Higgs model produce higher dimensional operators that make contributions to electroweak observables that are typically too large. To avoid this problem a discrete symmetry dubbed T-parity can be introduced to forbid the dangerous couplings. However, it was realized that in simple group models such as the littlest Higgs model, the implementation of T-parity in a UV completion could present some challenges. The situation is analogous to the one in QCD where the pion can easily be defined as being odd under a new $Z_2$ symmetry in the chiral Lagrangian, but this $Z_2$ is not a symmetry of the quark Lagrangian. In this paper we examine the possibility of implementing a T-parity in the low energy $SU(6)/Sp(6)$ model that might be easier to realize in the UV. In our model, the T-parity acts on the low energy non-linear sigma model field in way which is different to what was originally proposed for the Littlest Higgs, and lead to a different low energy theory. In particular, the Higgs sector of this model is a inert two Higgs doublets model with an approximate custodial symmetry. We examine the contributions of the various sectors of the model to electroweak precision data, and to the dark matter abundance.
1901.10102
Saul Ramos-Sanchez
Yessenia Olguin-Trejo, Omar Perez-Figueroa, Ricardo Perez-Martinez and Saul Ramos-Sanchez
U(1)' coupling constant at low energies from heterotic orbifolds
19 pages, 4 figures, 4 tables; v2: matches version published in PLB
null
10.1016/j.physletb.2019.06.065
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Additional Abelian gauge interactions are generic to string compactifications. In heterotic string models, gauge coupling unification of such forces and other gauge interactions is natural due to their common origin. In this letter we study systematically the 1-loop running of the coupling constants in effective vacua emerging from Z8 heterotic orbifold compactifications that provide the matter spectrum of the MSSM plus some vectorlike exotics, restricting to vacua that yield a non-anomalous U(1)' symmetry, gauge coupling unification and the observed values of known gauge couplings. We determine the low-energy value of the U(1)' coupling constant for different scales of supersymmetry breakdown. We find that the U(1)' coupling constant is quite restricted in string models to lie in the range 0.46-0.7 for low-scale supersymmetry or 0.44-0.6 in other cases. We argue that the phenomenology of these string vacua should be further explored to solve some extant issues, such as the stability of the Higgs vacuum.
[ { "created": "Tue, 29 Jan 2019 05:07:24 GMT", "version": "v1" }, { "created": "Mon, 17 Jun 2019 17:04:25 GMT", "version": "v2" } ]
2019-07-10
[ [ "Olguin-Trejo", "Yessenia", "" ], [ "Perez-Figueroa", "Omar", "" ], [ "Perez-Martinez", "Ricardo", "" ], [ "Ramos-Sanchez", "Saul", "" ] ]
Additional Abelian gauge interactions are generic to string compactifications. In heterotic string models, gauge coupling unification of such forces and other gauge interactions is natural due to their common origin. In this letter we study systematically the 1-loop running of the coupling constants in effective vacua emerging from Z8 heterotic orbifold compactifications that provide the matter spectrum of the MSSM plus some vectorlike exotics, restricting to vacua that yield a non-anomalous U(1)' symmetry, gauge coupling unification and the observed values of known gauge couplings. We determine the low-energy value of the U(1)' coupling constant for different scales of supersymmetry breakdown. We find that the U(1)' coupling constant is quite restricted in string models to lie in the range 0.46-0.7 for low-scale supersymmetry or 0.44-0.6 in other cases. We argue that the phenomenology of these string vacua should be further explored to solve some extant issues, such as the stability of the Higgs vacuum.
1005.0397
Maria Ubiali Ms
Maria Ubiali, Richard D. Ball, Luigi Del Debbio, Stefano Forte, Alberto Guffanti, Jos\'e I. Latorre and Juan Rojo
Combined PDF and strong coupling uncertainties at the LHC with NNPDF2.0
4 pages, 2 figures, contribution for the proceedings of the conference "Rencontres de Moriond, QCD and High Energy Interactions", 2010
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present predictions for relevant LHC observables obtained with the NNPDF2.0 set. We compute the combined PDFs uncertainties on these observables, and show that combining errors in quadrature yields an excellent approximation to exact error propagation. We then compare the NNPDF2.0 results to the other global PDF fits using a common value of $\alpha_s$. At LHC 7 TeV, reasonable agreement, both in central values and in uncertainties, is found for NNPDF2.0, CTEQ6.6 and MSTW08.
[ { "created": "Mon, 3 May 2010 20:22:42 GMT", "version": "v1" } ]
2010-05-05
[ [ "Ubiali", "Maria", "" ], [ "Ball", "Richard D.", "" ], [ "Del Debbio", "Luigi", "" ], [ "Forte", "Stefano", "" ], [ "Guffanti", "Alberto", "" ], [ "Latorre", "José I.", "" ], [ "Rojo", "Juan", "" ] ]
We present predictions for relevant LHC observables obtained with the NNPDF2.0 set. We compute the combined PDFs uncertainties on these observables, and show that combining errors in quadrature yields an excellent approximation to exact error propagation. We then compare the NNPDF2.0 results to the other global PDF fits using a common value of $\alpha_s$. At LHC 7 TeV, reasonable agreement, both in central values and in uncertainties, is found for NNPDF2.0, CTEQ6.6 and MSTW08.
2401.16257
Maibam Ricky Devi
Maibam Ricky Devi
Neutrino Masses and Higher Degree Siegel Modular Forms
19 pages, 6 figures, 1 table
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we have analyzed a neutrino model within the distinct framework of modular forms with degree, $ g>1 $ . This offers a more generalized scenario of modular forms which is popularly known as Siegel modular forms. We explore the implications of this special case of automorphic forms for physics beyond the standard model (BSM) within the lepton sector. In our model, we explicitly treat the Yukawa couplings as Siegel modular forms with both degree and level being equivalent to 2. We restrict our modulus parameter for $ \tau_{1}=\tau_{2} $ spanning within the finite modular $ S_{4}\times Z_{2} $ space. This helps us for a broader understanding of the multiplets at higher degree and simplifies the process of model building of the fermion masses. At the end, we compute the unknown neutrino oscillation parameters and find the optimal values of the modulus parameters $ \tau_{1} $ and $ \tau_{3} $ for which the values of the Yukawa couplings are consistent at $ 3\sigma $ for the input parameters of neutrinos as given in NuFIT 5.2 and discuss its underlying physics.
[ { "created": "Mon, 29 Jan 2024 16:07:50 GMT", "version": "v1" }, { "created": "Fri, 9 Feb 2024 02:35:44 GMT", "version": "v2" } ]
2024-02-12
[ [ "Devi", "Maibam Ricky", "" ] ]
In this work, we have analyzed a neutrino model within the distinct framework of modular forms with degree, $ g>1 $ . This offers a more generalized scenario of modular forms which is popularly known as Siegel modular forms. We explore the implications of this special case of automorphic forms for physics beyond the standard model (BSM) within the lepton sector. In our model, we explicitly treat the Yukawa couplings as Siegel modular forms with both degree and level being equivalent to 2. We restrict our modulus parameter for $ \tau_{1}=\tau_{2} $ spanning within the finite modular $ S_{4}\times Z_{2} $ space. This helps us for a broader understanding of the multiplets at higher degree and simplifies the process of model building of the fermion masses. At the end, we compute the unknown neutrino oscillation parameters and find the optimal values of the modulus parameters $ \tau_{1} $ and $ \tau_{3} $ for which the values of the Yukawa couplings are consistent at $ 3\sigma $ for the input parameters of neutrinos as given in NuFIT 5.2 and discuss its underlying physics.
0910.3020
Peter Graham
Peter W. Graham, Ahmed Ismail, Surjeet Rajendran, Prashant Saraswat
A Little Solution to the Little Hierarchy Problem: A Vector-like Generation
19 pages, 3 figures. v2: Section 3 modified, version to appear in PRD.
Phys.Rev.D81:055016,2010
10.1103/PhysRevD.81.055016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a simple solution to the little hierarchy problem in the MSSM: a vector-like fourth generation. With O(1) Yukawa couplings for the new quarks, the Higgs mass can naturally be above 114 GeV. Unlike a chiral fourth generation, a vector-like generation can solve the little hierarchy problem while remaining consistent with precision electroweak and direct production constraints, and maintaining the success of the grand unified framework. The new quarks are predicted to lie between ~ 300 - 600 GeV and will thus be discovered or ruled out at the LHC. This scenario suggests exploration of several novel collider signatures.
[ { "created": "Fri, 16 Oct 2009 02:13:41 GMT", "version": "v1" }, { "created": "Wed, 31 Mar 2010 22:19:19 GMT", "version": "v2" } ]
2014-11-20
[ [ "Graham", "Peter W.", "" ], [ "Ismail", "Ahmed", "" ], [ "Rajendran", "Surjeet", "" ], [ "Saraswat", "Prashant", "" ] ]
We present a simple solution to the little hierarchy problem in the MSSM: a vector-like fourth generation. With O(1) Yukawa couplings for the new quarks, the Higgs mass can naturally be above 114 GeV. Unlike a chiral fourth generation, a vector-like generation can solve the little hierarchy problem while remaining consistent with precision electroweak and direct production constraints, and maintaining the success of the grand unified framework. The new quarks are predicted to lie between ~ 300 - 600 GeV and will thus be discovered or ruled out at the LHC. This scenario suggests exploration of several novel collider signatures.
1201.4640
Vladimir Saleev
Vladimir Saleev and Alexandra Shipilova
Inclusive b-jet and b\bar b-dijet production at the LHC via Reggeized gluons
13 pages, 9 figures
Phys.Rev. D86 (2012) 034032
10.1103/PhysRevD.86.034032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study inclusive $b$-jet and $b\bar b$-dijet production at the CERN LHC invoking the hypothesis of gluon Reggeization in $t$-channel exchanges at high energy. The $b$-jet cross section includes contributions from open $b$-quark production and from $b$-quark production via gluon-to-bottom-pair fragmentation. The transverse-momentum distributions of inclusive $b$-jet production measured with the ATLAS detector at the CERN LHC in different rapidity ranges are calculated both within multi-Regge kinematics and quasi-multi-Regge kinematics. The $b\bar b$-dijet cross-section is calculated within quasi-multi-Regge kinematics as a function of the dijet invariant mass $M_{jj}$, the azimuthal angle between the two jets $\Delta\phi$ and the angular variable $\chi$. At the numerical calculation, we adopt the Kimber-Martin-Ryskin and Bl\"umlein prescriptions to derive unintegrated gluon distribution function of the proton from its collinear counterpart, for which we use the Martin-Roberts-Stirling-Thorne set. We find good agreement with measurements by the ATLAS and CMS Collaborations at the LHC at the hadronic c.m.\ energy of $\sqrt S=7$ TeV.
[ { "created": "Mon, 23 Jan 2012 07:41:22 GMT", "version": "v1" }, { "created": "Mon, 16 Jul 2012 06:53:26 GMT", "version": "v2" } ]
2013-05-30
[ [ "Saleev", "Vladimir", "" ], [ "Shipilova", "Alexandra", "" ] ]
We study inclusive $b$-jet and $b\bar b$-dijet production at the CERN LHC invoking the hypothesis of gluon Reggeization in $t$-channel exchanges at high energy. The $b$-jet cross section includes contributions from open $b$-quark production and from $b$-quark production via gluon-to-bottom-pair fragmentation. The transverse-momentum distributions of inclusive $b$-jet production measured with the ATLAS detector at the CERN LHC in different rapidity ranges are calculated both within multi-Regge kinematics and quasi-multi-Regge kinematics. The $b\bar b$-dijet cross-section is calculated within quasi-multi-Regge kinematics as a function of the dijet invariant mass $M_{jj}$, the azimuthal angle between the two jets $\Delta\phi$ and the angular variable $\chi$. At the numerical calculation, we adopt the Kimber-Martin-Ryskin and Bl\"umlein prescriptions to derive unintegrated gluon distribution function of the proton from its collinear counterpart, for which we use the Martin-Roberts-Stirling-Thorne set. We find good agreement with measurements by the ATLAS and CMS Collaborations at the LHC at the hadronic c.m.\ energy of $\sqrt S=7$ TeV.
hep-ph/9505231
Antonio Pich
A. Pich
QUANTUM CHROMODYNAMICS
LaTeX, 51 pages, 32 figures (included in separate .uu file) Lectures at the 1994 European School of High-Energy Physics (Sorrento, 1994)
null
null
FTUV/95-19; IFIC/95-19
hep-ph
null
These lectures provide an overview of Quantum Chromodynamics (QCD), the $SU(3)_C$ gauge theory of the strong interactions. After briefly reviewing the empirical considerations which lead to the introduction of {\it colour}, the QCD Lagrangian is discussed. The running of the strong coupling and the associated property of {\it Asymptotic Freedom} are analyzed. Some selected experimental tests and the present knowledge of $\alpha_s$ are summarized. A short description of the QCD flavour symmetries and the {\it dynamical breaking of chiral symmetry} is also given.
[ { "created": "Thu, 4 May 1995 15:11:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pich", "A.", "" ] ]
These lectures provide an overview of Quantum Chromodynamics (QCD), the $SU(3)_C$ gauge theory of the strong interactions. After briefly reviewing the empirical considerations which lead to the introduction of {\it colour}, the QCD Lagrangian is discussed. The running of the strong coupling and the associated property of {\it Asymptotic Freedom} are analyzed. Some selected experimental tests and the present knowledge of $\alpha_s$ are summarized. A short description of the QCD flavour symmetries and the {\it dynamical breaking of chiral symmetry} is also given.
hep-ph/0507128
Pedro Miguel Martins Ferreira
A. Barroso and P.M. Ferreira
Charge breaking bounds in the Zee model
null
Phys.Rev. D72 (2005) 075010
10.1103/PhysRevD.72.075010
null
hep-ph
null
We study the possibility that charge breaking minima occur in the Zee model. We reach very different conclusions from those attained in simpler, two Higgs doublet models, and the reason for this is traced back to the existence of cubic terms in the potential. A scan of the Zee model's parameter space shows that CB is restricted to a narrow region of values of the parameters.
[ { "created": "Mon, 11 Jul 2005 15:21:34 GMT", "version": "v1" }, { "created": "Thu, 29 Sep 2005 14:09:08 GMT", "version": "v2" }, { "created": "Tue, 11 Oct 2005 15:46:08 GMT", "version": "v3" } ]
2009-11-11
[ [ "Barroso", "A.", "" ], [ "Ferreira", "P. M.", "" ] ]
We study the possibility that charge breaking minima occur in the Zee model. We reach very different conclusions from those attained in simpler, two Higgs doublet models, and the reason for this is traced back to the existence of cubic terms in the potential. A scan of the Zee model's parameter space shows that CB is restricted to a narrow region of values of the parameters.
1103.4762
Valery Lyubovitskij
Yubing Dong, Amand Faessler, Thomas Gutsche, S. Kumano, Valery E. Lyubovitskij
Strong three-body decays of Lambdac(2940)+
9 pages, 1 figure
Phys.Rev.D83:094005,2011
10.1103/PhysRevD.83.094005
KEK-TH-1444
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Lambdac(2940)+ baryon with quantum numbers J(P) = 1/2(+) is considered as a hadronic molecule composed of a nucleon and D* meson. We give predictions for the width of the strong three-body decay processes Lambdac(2940)+ to Lambdac(2286)+ pi(+) pi(-) and Lambdac(2940)+ to Lambdac(2286)+ pi(0) pi(0) in this interpretation. Upcoming experimental facilities like a Super B factory at KEK or LHCb might be able to provide data on these decay modes.
[ { "created": "Thu, 24 Mar 2011 13:30:59 GMT", "version": "v1" } ]
2011-05-13
[ [ "Dong", "Yubing", "" ], [ "Faessler", "Amand", "" ], [ "Gutsche", "Thomas", "" ], [ "Kumano", "S.", "" ], [ "Lyubovitskij", "Valery E.", "" ] ]
The Lambdac(2940)+ baryon with quantum numbers J(P) = 1/2(+) is considered as a hadronic molecule composed of a nucleon and D* meson. We give predictions for the width of the strong three-body decay processes Lambdac(2940)+ to Lambdac(2286)+ pi(+) pi(-) and Lambdac(2940)+ to Lambdac(2286)+ pi(0) pi(0) in this interpretation. Upcoming experimental facilities like a Super B factory at KEK or LHCb might be able to provide data on these decay modes.
1911.02591
Luca Di Luzio
Luca Di Luzio
Flavour Violating Axions
9 pages, 2 figures. Talk given at the Workshop `Flavour changing and conserving processes' 29-31 August 2019 (Capri Island, Italy). v2: references added
null
10.1051/epjconf/202023401005
DESY 19-193
hep-ph
http://creativecommons.org/licenses/by/4.0/
I review the physics case for flavour violating axions. In particular, I argue that relaxing the assumption of the universality of the Peccei-Quinn current opens up new pathways, including: the relaxation of the Supernova bound on the axion mass, a possible connection with the Standard Model flavour puzzle and the experimental opportunity of discovering the axion via flavoured axion searches.
[ { "created": "Wed, 6 Nov 2019 19:05:12 GMT", "version": "v1" }, { "created": "Fri, 20 Dec 2019 11:54:10 GMT", "version": "v2" } ]
2020-05-20
[ [ "Di Luzio", "Luca", "" ] ]
I review the physics case for flavour violating axions. In particular, I argue that relaxing the assumption of the universality of the Peccei-Quinn current opens up new pathways, including: the relaxation of the Supernova bound on the axion mass, a possible connection with the Standard Model flavour puzzle and the experimental opportunity of discovering the axion via flavoured axion searches.
1202.0148
Michael Sarrazin
Michael Sarrazin, Fabrice Petit
Matter swapping between two braneworlds from the equivalence between two-brane worlds and noncommutative two-sheeted spacetimes
3 pages. Published in the proceedings of the 2011 Europhysics Conference on High Energy Physics - HEP 2011, July 21-27 2011, Grenoble, France. Poster session contribution. The manuscript has overlap with arXiv:0903.2498 and arXiv:0809.2060, which are extensively more detailed. The present paper is deposited as a convenient summary of previous works and further studies
PoS(EPS-HEP2011)472
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that a two-brane world made of two domain walls can be seen as a noncommutative two-sheeted spacetime under certain assumptions. This equivalence implies a model-independent phenomenology: Matter swapping between the two 3-branes (or sheets) is predicted through fermionic oscillations induced by magnetic vector potentials. This phenomenon, which might be experimentally studied, could reveal the existence of extra dimensions in a new and very affordable way.
[ { "created": "Wed, 1 Feb 2012 11:33:27 GMT", "version": "v1" } ]
2012-02-02
[ [ "Sarrazin", "Michael", "" ], [ "Petit", "Fabrice", "" ] ]
It is shown that a two-brane world made of two domain walls can be seen as a noncommutative two-sheeted spacetime under certain assumptions. This equivalence implies a model-independent phenomenology: Matter swapping between the two 3-branes (or sheets) is predicted through fermionic oscillations induced by magnetic vector potentials. This phenomenon, which might be experimentally studied, could reveal the existence of extra dimensions in a new and very affordable way.
1205.1948
Juan Racker
J. Racker, Manuel Pe\~na, Nuria Rius
Leptogenesis with small violation of B-L
20 pages, 3 figures
null
10.1088/1475-7516/2012/07/030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze leptogenesis in the context of seesaw models with almost conserved lepton number, focusing on the L-conserving contribution to the flavoured CP asymmetries. We find that, contrary to previous claims, successful leptogenesis is feasible for masses of the lightest heavy neutrino as low as M1 ~ 10^6 GeV, without resorting to the resonant enhancement of the CP asymmetry for strongly degenerate heavy neutrinos. This lower limit renders thermal leptogenesis compatible with the gravitino bound in supersymmetric scenarios.
[ { "created": "Wed, 9 May 2012 11:57:50 GMT", "version": "v1" }, { "created": "Wed, 25 Sep 2013 18:06:18 GMT", "version": "v2" } ]
2015-06-05
[ [ "Racker", "J.", "" ], [ "Peña", "Manuel", "" ], [ "Rius", "Nuria", "" ] ]
We analyze leptogenesis in the context of seesaw models with almost conserved lepton number, focusing on the L-conserving contribution to the flavoured CP asymmetries. We find that, contrary to previous claims, successful leptogenesis is feasible for masses of the lightest heavy neutrino as low as M1 ~ 10^6 GeV, without resorting to the resonant enhancement of the CP asymmetry for strongly degenerate heavy neutrinos. This lower limit renders thermal leptogenesis compatible with the gravitino bound in supersymmetric scenarios.
hep-ph/9710258
David Dooling
David Dooling, Kyungsik Kang, Sin Kyu Kang
Bounds on the lightest Higgs boson mass with three and four fermion generations
24 pages, 10 figures, Some additional discussion added. Final version to be published in International Journal of Modern Physics A
Int.J.Mod.Phys. A14 (1999) 1605-1632
10.1142/S0217751X99000816
BROWN-HET-1094 ANL-HEP-PR-97-64
hep-ph
null
We present lower bounds on the Higgs boson mass in the Standard Model with three and four fermion generations SM(3,4), as well as upper bounds on the lightest Higgs boson mass in the minimal supersymmetric extension of the SM with three and four generations MSSM(3,4). Our analysis utilizes the SM(3,4) renormalization-group-improved one-loop effective potential of the Higgs boson to find the upper bounds on the Higgs mass in the MSSM(3,4) while the lower bounds in the SM(3,4) are derived from considerations of vacuum stability. All the bounds increase as the degenerate fourth generation mass increases, providing more room in theory space that respects the increasing experimental lower limit of the Higgs mass.
[ { "created": "Tue, 7 Oct 1997 01:29:49 GMT", "version": "v1" }, { "created": "Mon, 26 Oct 1998 21:24:41 GMT", "version": "v2" } ]
2009-10-30
[ [ "Dooling", "David", "" ], [ "Kang", "Kyungsik", "" ], [ "Kang", "Sin Kyu", "" ] ]
We present lower bounds on the Higgs boson mass in the Standard Model with three and four fermion generations SM(3,4), as well as upper bounds on the lightest Higgs boson mass in the minimal supersymmetric extension of the SM with three and four generations MSSM(3,4). Our analysis utilizes the SM(3,4) renormalization-group-improved one-loop effective potential of the Higgs boson to find the upper bounds on the Higgs mass in the MSSM(3,4) while the lower bounds in the SM(3,4) are derived from considerations of vacuum stability. All the bounds increase as the degenerate fourth generation mass increases, providing more room in theory space that respects the increasing experimental lower limit of the Higgs mass.
1212.0846
Vladimir Karmanov
V.A. Karmanov, J. Carbonell
Scattering states in Bethe-Salpeter equation
7 pages, 3 figures. Presented at the XXI International Baldin Seminar on High Energy Physics Problems, September 10-15, 2012, JINR, Dubna, Russia. To be published in the online journal Proceedings of Science - PoS(Baldin ISHEPP XXI)027 (2012)
null
null
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The off-mass shell scattering amplitude, satisfying the Bethe-Salpeter equation for spinless particles in Minkowski space with the ladder kernel, is computed for the first time.
[ { "created": "Tue, 4 Dec 2012 20:24:04 GMT", "version": "v1" } ]
2012-12-05
[ [ "Karmanov", "V. A.", "" ], [ "Carbonell", "J.", "" ] ]
The off-mass shell scattering amplitude, satisfying the Bethe-Salpeter equation for spinless particles in Minkowski space with the ladder kernel, is computed for the first time.
1311.5968
Mikhail Smolyakov
E.E. Boos, V.E. Bunichev, M.A. Perfilov, M.N. Smolyakov, I.P. Volobuev
The specificity of searches for $W^{\prime}$, $Z^{\prime}$ and $\gamma^{\prime}$ coming from extra dimensions
14 pages, 12 figures, LaTeX. References added, figures added, text enlarged
JHEP 06 (2014) 160
10.1007/JHEP06(2014)160
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the specificity of searches for hypothetical $W^{\prime}$, $Z^{\prime}$ and $\gamma^{\prime}$ bosons at hadron colliders in single top quark and $\mu^{+}\nu_{\mu}$ production and Drell-Yan processes assuming these particles to be the Kaluza-Klein excitations of the gauge bosons of the Standard Model. In this case any process mediated by $W$ is also mediated by the whole KK tower of its excitations, whereas to the processes mediated by $Z$ and $\gamma$ there is not only a contribution from their KK towers, but also from that of the graviton. The contributions of the towers above $W^{\prime}$, $Z^{\prime}$ and $\gamma^{\prime}$ and above the first excitation of the graviton are included with the help of effective four-fermion Lagrangians. We compute the cross-sections of these processes taking into account the contributions of the Standard Model gauge bosons, of their first KK modes and of the corresponding KK towers and discuss the impact of the interference between them. For pp-collisions at the LHC with the center of mass energy 14 TeV we found specific changes of the distribution tails due to the interference effects. Such a modification of distribution tails is characteristic for the processes mediated by particles coming from extra dimensions and should always be taken into account when looking for them.
[ { "created": "Sat, 23 Nov 2013 07:24:49 GMT", "version": "v1" }, { "created": "Thu, 28 Nov 2013 19:58:33 GMT", "version": "v2" }, { "created": "Mon, 30 Jun 2014 19:42:48 GMT", "version": "v3" } ]
2014-07-01
[ [ "Boos", "E. E.", "" ], [ "Bunichev", "V. E.", "" ], [ "Perfilov", "M. A.", "" ], [ "Smolyakov", "M. N.", "" ], [ "Volobuev", "I. P.", "" ] ]
We discuss the specificity of searches for hypothetical $W^{\prime}$, $Z^{\prime}$ and $\gamma^{\prime}$ bosons at hadron colliders in single top quark and $\mu^{+}\nu_{\mu}$ production and Drell-Yan processes assuming these particles to be the Kaluza-Klein excitations of the gauge bosons of the Standard Model. In this case any process mediated by $W$ is also mediated by the whole KK tower of its excitations, whereas to the processes mediated by $Z$ and $\gamma$ there is not only a contribution from their KK towers, but also from that of the graviton. The contributions of the towers above $W^{\prime}$, $Z^{\prime}$ and $\gamma^{\prime}$ and above the first excitation of the graviton are included with the help of effective four-fermion Lagrangians. We compute the cross-sections of these processes taking into account the contributions of the Standard Model gauge bosons, of their first KK modes and of the corresponding KK towers and discuss the impact of the interference between them. For pp-collisions at the LHC with the center of mass energy 14 TeV we found specific changes of the distribution tails due to the interference effects. Such a modification of distribution tails is characteristic for the processes mediated by particles coming from extra dimensions and should always be taken into account when looking for them.
hep-ph/9811500
Gautam Bhattacharyya
Subhendu Rakshit, Gautam Bhattacharyya and Amitava Raychaudhuri
R-parity-violating trilinear couplings and recent neutrino data
Latex, 8 pages, including 1 Fig; minor changes in the text, some references added, to appear in Phys. Rev. D (Rapid Communication)
Phys. Rev. D 59, 091701 (1999)
10.1103/PhysRevD.59.091701
SINP/TNP/98-31, CUPP--98/2
hep-ph
null
The nontrivial structure of the neutrino mass matrix, suggested by the recent Super-Kamiokande results and data from other neutrino experiments, can be reproduced in R-parity-violating supersymmetric theories. This requires sets of products of R-parity-violating trilinear couplings to take appropriately chosen values. It is shown that the existing constraints on these couplings are satisfied by these choices.
[ { "created": "Sat, 28 Nov 1998 08:17:30 GMT", "version": "v1" }, { "created": "Wed, 10 Feb 1999 10:18:42 GMT", "version": "v2" } ]
2016-08-25
[ [ "Rakshit", "Subhendu", "" ], [ "Bhattacharyya", "Gautam", "" ], [ "Raychaudhuri", "Amitava", "" ] ]
The nontrivial structure of the neutrino mass matrix, suggested by the recent Super-Kamiokande results and data from other neutrino experiments, can be reproduced in R-parity-violating supersymmetric theories. This requires sets of products of R-parity-violating trilinear couplings to take appropriately chosen values. It is shown that the existing constraints on these couplings are satisfied by these choices.