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1906.11098
R. Sekhar Chivukula
R. Sekhar Chivukula, Dennis Foren, Kirtimaan A Mohan, Dipan Sengupta, and Elizabeth Simmons
Scattering Amplitudes of Massive Spin-2 Kaluza-Klein States Grow Only as ${\cal O}(s)$
10 pages, one included tikz figure. References added. Modified per referee comments, and shortened
Phys. Rev. D 101, 055013 (2020)
10.1103/PhysRevD.101.055013
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the results of the first complete calculation of the tree-level $2\to 2$ high-energy scattering amplitudes of the longitudinal modes of massive spin-2 Kaluza-Klein states, both in the case where the internal space is a torus and in the Randall-Sundrum model where the internal space has constant negative curvature. While individual contributions to this amplitude grow as ${\cal O}(s^5$), we demonstrate explicitly that intricate cancellations occur between different contributions, reducing the growth to ${\cal O}(s)$, a slower rate of growth than previously argued in the literature. These cancellations require subtle relationships between the masses of the Kaluza-Klein states and their interactions, and reflect the underlying higher-dimensional diffeomorphism invariance. Our results provide fresh perspective on the range of validity of (effective) field theories involving massive spin-2 KK particles, with significant implications for the theory and phenomenology of these states.
[ { "created": "Wed, 26 Jun 2019 13:46:00 GMT", "version": "v1" }, { "created": "Mon, 1 Jul 2019 18:20:57 GMT", "version": "v2" }, { "created": "Thu, 17 Oct 2019 02:59:35 GMT", "version": "v3" } ]
2020-03-11
[ [ "Chivukula", "R. Sekhar", "" ], [ "Foren", "Dennis", "" ], [ "Mohan", "Kirtimaan A", "" ], [ "Sengupta", "Dipan", "" ], [ "Simmons", "Elizabeth", "" ] ]
We present the results of the first complete calculation of the tree-level $2\to 2$ high-energy scattering amplitudes of the longitudinal modes of massive spin-2 Kaluza-Klein states, both in the case where the internal space is a torus and in the Randall-Sundrum model where the internal space has constant negative curvature. While individual contributions to this amplitude grow as ${\cal O}(s^5$), we demonstrate explicitly that intricate cancellations occur between different contributions, reducing the growth to ${\cal O}(s)$, a slower rate of growth than previously argued in the literature. These cancellations require subtle relationships between the masses of the Kaluza-Klein states and their interactions, and reflect the underlying higher-dimensional diffeomorphism invariance. Our results provide fresh perspective on the range of validity of (effective) field theories involving massive spin-2 KK particles, with significant implications for the theory and phenomenology of these states.
1310.2005
Bo-Qiang Ma
Yujie Chi, Bo-Qiang Ma
Quark to $\Lambda$-hyperon spin transfers in the current-fragmentation region
14 latex pages, 8 figures. Final version for publication in PLB
null
10.1016/j.physletb.2013.09.044
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a study on the struck quark to the $\Lambda$-hyperon fragmentation processes by taking into account the anti-quark fragmentations and intermediate decays from other hyperons. We concentrate on how the longitudinally polarized quark fragments to the longitudinally polarized $\Lambda$, how unpolarized quark and anti-quark fragment to the unpolarized $\Lambda$, and how quark and anti-quark fragment to the $\Lambda$ through the intermediate decay processes. We calculate the effective fragmentation functions in the light-cone SU(6) quark-spectator-diquark model via the Gribov-Lipatov relation, with the Melosh-Wigner rotation effect also included. The calculated results are in reasonable agreement with the HERMES semi-inclusive $ep$ experimental data and the OPAL and ALEPH $e^{+}e^{-}$ annihilation experimental data.
[ { "created": "Tue, 8 Oct 2013 05:12:43 GMT", "version": "v1" } ]
2013-10-09
[ [ "Chi", "Yujie", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We perform a study on the struck quark to the $\Lambda$-hyperon fragmentation processes by taking into account the anti-quark fragmentations and intermediate decays from other hyperons. We concentrate on how the longitudinally polarized quark fragments to the longitudinally polarized $\Lambda$, how unpolarized quark and anti-quark fragment to the unpolarized $\Lambda$, and how quark and anti-quark fragment to the $\Lambda$ through the intermediate decay processes. We calculate the effective fragmentation functions in the light-cone SU(6) quark-spectator-diquark model via the Gribov-Lipatov relation, with the Melosh-Wigner rotation effect also included. The calculated results are in reasonable agreement with the HERMES semi-inclusive $ep$ experimental data and the OPAL and ALEPH $e^{+}e^{-}$ annihilation experimental data.
2012.07867
Damiano Francesco Giuseppe Fiorillo
Damiano F. G. Fiorillo, Gianpiero Mangano, Stefano Morisi and Ofelia Pisanti
IceCube constraints on Violation of Equivalence Principle
9 pages, 3 figures
JCAP 04 (2021) 079
10.1088/1475-7516/2021/04/079
null
hep-ph astro-ph.HE gr-qc hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Among the information provided by high energy neutrinos, a promising possibility is to analyze the effects of a Violation of Equivalence Principle (VEP) on neutrino oscillations. We analyze the recently released IceCube data on atmospheric neutrino fluxes under the assumption of a VEP and obtain updated constraints on the parameter space with the benchmark choice that neutrinos with different masses couple with different strengths to the gravitational field. In this case we find that the VEP parameters times the local gravitational potential at Earth can be constrained at the level of $10^{-27}$. We show that the constraints from atmospheric neutrinos strongly depend on the assumption that the neutrino eigenstates interacting diagonally with the gravitational field coincide with the mass eigenstates, which is not \textit{a priori} justified: this is particularly clear in the case that the basis of diagonal gravitational interaction coincide with the flavor basis, which cannot be constrained by the observation of atmospheric neutrinos. Finally, we quantitatively study the effect of a VEP on the flavor composition of the astrophysical neutrinos, stressing again the interplay with the basis in which the VEP is diagonal: we find that for some choices of such basis the flavor ratio measured by IceCube can significantly change.
[ { "created": "Mon, 14 Dec 2020 19:00:05 GMT", "version": "v1" }, { "created": "Wed, 19 May 2021 13:15:30 GMT", "version": "v2" } ]
2021-05-20
[ [ "Fiorillo", "Damiano F. G.", "" ], [ "Mangano", "Gianpiero", "" ], [ "Morisi", "Stefano", "" ], [ "Pisanti", "Ofelia", "" ] ]
Among the information provided by high energy neutrinos, a promising possibility is to analyze the effects of a Violation of Equivalence Principle (VEP) on neutrino oscillations. We analyze the recently released IceCube data on atmospheric neutrino fluxes under the assumption of a VEP and obtain updated constraints on the parameter space with the benchmark choice that neutrinos with different masses couple with different strengths to the gravitational field. In this case we find that the VEP parameters times the local gravitational potential at Earth can be constrained at the level of $10^{-27}$. We show that the constraints from atmospheric neutrinos strongly depend on the assumption that the neutrino eigenstates interacting diagonally with the gravitational field coincide with the mass eigenstates, which is not \textit{a priori} justified: this is particularly clear in the case that the basis of diagonal gravitational interaction coincide with the flavor basis, which cannot be constrained by the observation of atmospheric neutrinos. Finally, we quantitatively study the effect of a VEP on the flavor composition of the astrophysical neutrinos, stressing again the interplay with the basis in which the VEP is diagonal: we find that for some choices of such basis the flavor ratio measured by IceCube can significantly change.
hep-ph/0006150
Ulrich Heinz
Ulrich Heinz, Pierre Scotto, and Qing-Hui Zhang
Multi-boson effects in Bose-Einstein interferometry and the multiplicity distribution
22 pages ReVTex, including 8 postscript figures. Submitted to Annals of Physics (N.Y.)
Annals Phys.288:325-360,2001
10.1006/aphy.2000.6103
CERN-TH/2000-123
hep-ph
null
Multi-boson symmetrization effects on two-particle Bose-Einstein interferometry are studied for ensembles with arbitrary multiplicity distributions. This generalizes the previously studied case of a Poissonian input multiplicity distribution. In the general case we find interesting residual correlations which require a modified framework for extracting information on the source geometry from two-particle correlation measurements. In sources with high phase-space densities, multi-boson effects modify the Hanbury Brown-Twiss (HBT) radius parameters and simultaneously generate strong residual correlations. We clarify their effect on the correlation strength (intercept parameter) and thus explain a variety of previously reported puzzling multi-boson symmetrization phenomena. Using a class of analytically solvable Gaussian source models, with and without space-momentum correlations, we present a comprehensive overview of multi-boson symmetrization effects on particle interferometry. For event ensembles of (approximately) fixed multiplicity, the residual correlations lead to a minimum in the correlation function at non-zero relative momentum, which can be practically exploited to search, in a model-independent way, for multi-boson symmetrization effects in high-energy heavy-ion experiments.
[ { "created": "Wed, 14 Jun 2000 08:33:33 GMT", "version": "v1" } ]
2009-10-09
[ [ "Heinz", "Ulrich", "" ], [ "Scotto", "Pierre", "" ], [ "Zhang", "Qing-Hui", "" ] ]
Multi-boson symmetrization effects on two-particle Bose-Einstein interferometry are studied for ensembles with arbitrary multiplicity distributions. This generalizes the previously studied case of a Poissonian input multiplicity distribution. In the general case we find interesting residual correlations which require a modified framework for extracting information on the source geometry from two-particle correlation measurements. In sources with high phase-space densities, multi-boson effects modify the Hanbury Brown-Twiss (HBT) radius parameters and simultaneously generate strong residual correlations. We clarify their effect on the correlation strength (intercept parameter) and thus explain a variety of previously reported puzzling multi-boson symmetrization phenomena. Using a class of analytically solvable Gaussian source models, with and without space-momentum correlations, we present a comprehensive overview of multi-boson symmetrization effects on particle interferometry. For event ensembles of (approximately) fixed multiplicity, the residual correlations lead to a minimum in the correlation function at non-zero relative momentum, which can be practically exploited to search, in a model-independent way, for multi-boson symmetrization effects in high-energy heavy-ion experiments.
1712.07957
Feng-Kun Guo
Meng-Lin Du, Miguel Albaladejo, Pedro Fernandez-Soler, Feng-Kun Guo, Christoph Hanhart, Ulf-G. Mei{\ss}ner, Juan Nieves, De-Liang Yao
Towards a new paradigm for heavy-light meson spectroscopy
8 pages, 5 figures. Discussion significantly extended, suggestion for lattice and more comparison with LHCb data added; version accepted for publication in PRD
Phys. Rev. D 98, 094018 (2018)
10.1103/PhysRevD.98.094018
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Since 2003 many new hadrons, including the lowest-lying positive-parity charm-strange mesons ${D_{s0}^*(2317)}$ and ${D_{s1}(2460)}$, were observed that do not conform with quark model expectations. It was recently demonstrated that various puzzles in the charm meson spectrum find a natural resolution, if the SU(3) multiplets for the lightest scalar and axial-vector states, amongst them the ${D_{s0}^*(2317)}$ and the ${D_{s1}(2460)}$, owe their existence to the nonperturbative dynamics of Goldstone-Boson scattering off $D_{(s)}$ and $D^*_{(s)}$ mesons. Most importantly the ordering of the lightest strange and nonstrange scalars becomes natural. In this work we demonstrate for the first time that this mechanism is strongly supported by the recent high quality data on the ${B^-\to D^+\pi^-\pi^- }$ provided by the LHCb experiment. This implies that the lowest quark-model positive-parity charm mesons, together with their bottom counterparts, if realized in nature, do not form the ground-state multiplet. This is similar to the pattern that has been established for the scalar mesons made from light up, down and strange quarks, where the lowest multiplet is considered to be made of states not described by the quark model. In a broader view, the hadron spectrum must be viewed as more than a collection of quark model states.
[ { "created": "Thu, 21 Dec 2017 14:20:51 GMT", "version": "v1" }, { "created": "Mon, 5 Nov 2018 14:37:22 GMT", "version": "v2" } ]
2018-11-28
[ [ "Du", "Meng-Lin", "" ], [ "Albaladejo", "Miguel", "" ], [ "Fernandez-Soler", "Pedro", "" ], [ "Guo", "Feng-Kun", "" ], [ "Hanhart", "Christoph", "" ], [ "Meißner", "Ulf-G.", "" ], [ "Nieves", "Juan", "" ], [ "Yao", "De-Liang", "" ] ]
Since 2003 many new hadrons, including the lowest-lying positive-parity charm-strange mesons ${D_{s0}^*(2317)}$ and ${D_{s1}(2460)}$, were observed that do not conform with quark model expectations. It was recently demonstrated that various puzzles in the charm meson spectrum find a natural resolution, if the SU(3) multiplets for the lightest scalar and axial-vector states, amongst them the ${D_{s0}^*(2317)}$ and the ${D_{s1}(2460)}$, owe their existence to the nonperturbative dynamics of Goldstone-Boson scattering off $D_{(s)}$ and $D^*_{(s)}$ mesons. Most importantly the ordering of the lightest strange and nonstrange scalars becomes natural. In this work we demonstrate for the first time that this mechanism is strongly supported by the recent high quality data on the ${B^-\to D^+\pi^-\pi^- }$ provided by the LHCb experiment. This implies that the lowest quark-model positive-parity charm mesons, together with their bottom counterparts, if realized in nature, do not form the ground-state multiplet. This is similar to the pattern that has been established for the scalar mesons made from light up, down and strange quarks, where the lowest multiplet is considered to be made of states not described by the quark model. In a broader view, the hadron spectrum must be viewed as more than a collection of quark model states.
0901.0927
Giacomo Cacciapaglia
Giacomo Cacciapaglia, Aldo Deandrea and Jeremie Llodra-Perez (Lyon, IPN)
Higgs to Gamma Gamma beyond the Standard Model
47 pages, 5 figures; references and UED case added
JHEP 0906:054,2009
10.1088/1126-6708/2009/06/054
LYCEN 2008-13
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the H to gamma gamma decay process and the gluon fusion production of a light Higgs, and provide a general framework for testing models of new physics beyond the Standard Model. We apply our parametrisation to typical models extending the Standard Model in 4 and 5 dimensions, and show how the parametrisation can be used to discriminate between different scenarios of new physics at the Large Hadron Collider and at future Linear Colliders.
[ { "created": "Wed, 7 Jan 2009 21:05:31 GMT", "version": "v1" }, { "created": "Mon, 26 Jan 2009 14:24:09 GMT", "version": "v2" } ]
2010-01-05
[ [ "Cacciapaglia", "Giacomo", "", "Lyon,\n IPN" ], [ "Deandrea", "Aldo", "", "Lyon,\n IPN" ], [ "Llodra-Perez", "Jeremie", "", "Lyon,\n IPN" ] ]
We consider the H to gamma gamma decay process and the gluon fusion production of a light Higgs, and provide a general framework for testing models of new physics beyond the Standard Model. We apply our parametrisation to typical models extending the Standard Model in 4 and 5 dimensions, and show how the parametrisation can be used to discriminate between different scenarios of new physics at the Large Hadron Collider and at future Linear Colliders.
2012.07099
Antonio Pich
Antonio Pich
Challenges for tau physics at the TeraZ
5 pages. References updated. Matches final publication in Eur. Phys. J. Plus
null
null
IFIC/20-52
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The very high statistics, low backgrounds and clean back-to-back kinematics of a TeraZ facility would provide an optimal laboratory for precision measurements of the $\tau$ properties. A few important topics in $\tau$ physics where very relevant contributions could be made are highlighted.
[ { "created": "Sun, 13 Dec 2020 16:55:23 GMT", "version": "v1" }, { "created": "Fri, 12 Nov 2021 17:46:48 GMT", "version": "v2" } ]
2021-11-15
[ [ "Pich", "Antonio", "" ] ]
The very high statistics, low backgrounds and clean back-to-back kinematics of a TeraZ facility would provide an optimal laboratory for precision measurements of the $\tau$ properties. A few important topics in $\tau$ physics where very relevant contributions could be made are highlighted.
1206.3957
Anton Ilderton
Victor Dinu, Thomas Heinzl, Anton Ilderton
Infra-red divergences in plane wave backgrounds
15 pages, 7 figures
null
10.1103/PhysRevD.86.085037
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the emission of soft photons via nonlinear Compton scattering in a pulsed plane wave (laser field) is in general infra-red divergent. We give examples of both soft and soft-collinear divergences, and we pay particular attention to the case of crossed fields in both classical and quantum theories.
[ { "created": "Mon, 18 Jun 2012 14:50:17 GMT", "version": "v1" } ]
2013-05-30
[ [ "Dinu", "Victor", "" ], [ "Heinzl", "Thomas", "" ], [ "Ilderton", "Anton", "" ] ]
We show that the emission of soft photons via nonlinear Compton scattering in a pulsed plane wave (laser field) is in general infra-red divergent. We give examples of both soft and soft-collinear divergences, and we pay particular attention to the case of crossed fields in both classical and quantum theories.
hep-ph/9206255
null
R. Sekhar Chivukula, Mitchell Golden, Dimitrios Kominis, and M. V. Ramana
The Phenomenology of a Hidden Symmetry Breaking Sector
harvmac, 8 pages (4 figures), BUHEP-92-23 new version corrects error in figures
Phys.Lett. B293 (1992) 400-404
10.1016/0370-2693(92)90903-H
null
hep-ph
null
We calculate the production rate of gauge-boson pairs at the SSC in a model with a ``hidden'' electroweak symmetry breaking sector. We show that the signal of electroweak symmetry breaking is lower than the background and that we cannot necessarily rely on gauge boson pairs as a signal of the dynamics of symmetry breaking.
[ { "created": "Fri, 26 Jun 1992 19:29:38 GMT", "version": "v1" }, { "created": "Tue, 21 Jul 1992 23:29:20 GMT", "version": "v2" } ]
2009-10-22
[ [ "Chivukula", "R. Sekhar", "" ], [ "Golden", "Mitchell", "" ], [ "Kominis", "Dimitrios", "" ], [ "Ramana", "M. V.", "" ] ]
We calculate the production rate of gauge-boson pairs at the SSC in a model with a ``hidden'' electroweak symmetry breaking sector. We show that the signal of electroweak symmetry breaking is lower than the background and that we cannot necessarily rely on gauge boson pairs as a signal of the dynamics of symmetry breaking.
hep-ph/9804347
Mikhail Volkov
M. K. Volkov (JINR, Dubna, Russia), M. Nagy (Institute of Physics, Bratislava, Slovakia), V. L. Yudichev (JINR, Dubna, Russia)
Scalar mesons in the Nambu--Jona-Lasinio model with 't Hooft interaction
LaTeX text, 8 pages
Nuovo Cim. A112 (1999) 225-232
10.1007/BF03035844
E2-98-101
hep-ph
null
We calculate the mass spectra of the pseudoscalar and scalar meson nonets in the Nambu--Jona-Lasinio model with the 't Hooft interaction. We obtain satisfactory result for the pseudoscalar mesons. For the scalar mesons, the 't Hooft interaction somewhat increases the values of the masses. However, it is not sufficient to explain the whole scalar mass spectrum. The situation could be improved for the $\sigma$ and $f_0$ mesons through mixing with the glueball state. For the description of the masses of $a_0$ and $\kstar$ mesons, it is necessary to involve the other models. The strong decay widths of the scalar mesons are described.
[ { "created": "Tue, 21 Apr 1998 19:44:05 GMT", "version": "v1" }, { "created": "Wed, 22 Apr 1998 08:29:35 GMT", "version": "v2" }, { "created": "Mon, 27 Apr 1998 17:24:21 GMT", "version": "v3" } ]
2009-10-31
[ [ "Volkov", "M. K.", "", "JINR, Dubna, Russia" ], [ "Nagy", "M.", "", "Institute of Physics,\n Bratislava, Slovakia" ], [ "Yudichev", "V. L.", "", "JINR, Dubna, Russia" ] ]
We calculate the mass spectra of the pseudoscalar and scalar meson nonets in the Nambu--Jona-Lasinio model with the 't Hooft interaction. We obtain satisfactory result for the pseudoscalar mesons. For the scalar mesons, the 't Hooft interaction somewhat increases the values of the masses. However, it is not sufficient to explain the whole scalar mass spectrum. The situation could be improved for the $\sigma$ and $f_0$ mesons through mixing with the glueball state. For the description of the masses of $a_0$ and $\kstar$ mesons, it is necessary to involve the other models. The strong decay widths of the scalar mesons are described.
1405.7168
Henry Tsz-King Wong
Jiunn-Wei Chen, Hsin-Chang Chi, Hau-Bin Li, C.-P. Liu, Lakhwinder Singh, Henry T. Wong, Chih-Liang Wu, and Chih-Pan Wu
Constraints on millicharged neutrinos via analysis of data from atomic ionizations with germanium detectors at sub-keV sensitivities
5 pages, 4 figures, 1 table ; Published Version as V2
Phys. Rev. D 90, 011301(R) (2014)
10.1103/PhysRevD.90.011301
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the advent of detectors with sub-keV sensitivities, atomic ionization has been identified as a promising avenue to probe possible neutrino electromagnetic properties. The interaction cross-sections induced by millicharged neutrinos are evaluated with the ab-initio multi-configuration relativistic random-phase approximation. There is significant enhancement at atomic binding energies compared to that when the electrons are taken as free particles. Positive signals would distinctly manifest as peaks at specific energies with known intensity ratios. Selected reactor neutrino data with germanium detectors at analysis threshold as low as 300 eV are studied. No such signatures are observed, and a combined limit on the neutrino charge fraction of | \numq | < 1.0 X 10^{-12} at 90% confidence level is derived.
[ { "created": "Wed, 28 May 2014 09:14:37 GMT", "version": "v1" }, { "created": "Thu, 31 Jul 2014 04:00:33 GMT", "version": "v2" } ]
2014-08-01
[ [ "Chen", "Jiunn-Wei", "" ], [ "Chi", "Hsin-Chang", "" ], [ "Li", "Hau-Bin", "" ], [ "Liu", "C. -P.", "" ], [ "Singh", "Lakhwinder", "" ], [ "Wong", "Henry T.", "" ], [ "Wu", "Chih-Liang", "" ], [ "Wu", "Chih-Pan", "" ] ]
With the advent of detectors with sub-keV sensitivities, atomic ionization has been identified as a promising avenue to probe possible neutrino electromagnetic properties. The interaction cross-sections induced by millicharged neutrinos are evaluated with the ab-initio multi-configuration relativistic random-phase approximation. There is significant enhancement at atomic binding energies compared to that when the electrons are taken as free particles. Positive signals would distinctly manifest as peaks at specific energies with known intensity ratios. Selected reactor neutrino data with germanium detectors at analysis threshold as low as 300 eV are studied. No such signatures are observed, and a combined limit on the neutrino charge fraction of | \numq | < 1.0 X 10^{-12} at 90% confidence level is derived.
hep-ph/9511306
Alexander Belyaev
A. Belyaev, E. Boos L. Dudko, A. Pukhov (Institute of Nuclear Physics, Moscow State University)
W+2jets production at Tevatron -- VECBOS and CompHEP comparison
8 pages including 4 figures as a gzipped postscript file
null
null
D0 Note 2784, November 13, 1995
hep-ph
null
Results of calculation of all subprocesses in proton-antiproton collisions which contribute to the W+2jets final state are presented at Tevatron energy. The calculation has been carried out by means of the CompHEP software package. A detail comparison with VECBOS generator results for cross sections and various distributions shows an agreement at the level of Monte-Carlo accuracy. Therefore the additional independent check of VECBOS generator has been done. In complement to the VECBOS generator a new generator based on CompHEP allows to study individual subprocesses like $Wb\bar{b}$ or $Wc\bar{c}$. The last point is important, for instance, for study $Wb\bar{b}$ part of the background for single top or Standard Model Higgs signal at Tevatron.
[ { "created": "Tue, 14 Nov 1995 00:40:16 GMT", "version": "v1" }, { "created": "Thu, 16 Nov 1995 02:43:40 GMT", "version": "v2" } ]
2008-02-03
[ [ "Belyaev", "A.", "", "Institute of Nuclear Physics,\n Moscow State University" ], [ "Dudko", "E. Boos L.", "", "Institute of Nuclear Physics,\n Moscow State University" ], [ "Pukhov", "A.", "", "Institute of Nuclear Physics,\n Moscow State University" ] ]
Results of calculation of all subprocesses in proton-antiproton collisions which contribute to the W+2jets final state are presented at Tevatron energy. The calculation has been carried out by means of the CompHEP software package. A detail comparison with VECBOS generator results for cross sections and various distributions shows an agreement at the level of Monte-Carlo accuracy. Therefore the additional independent check of VECBOS generator has been done. In complement to the VECBOS generator a new generator based on CompHEP allows to study individual subprocesses like $Wb\bar{b}$ or $Wc\bar{c}$. The last point is important, for instance, for study $Wb\bar{b}$ part of the background for single top or Standard Model Higgs signal at Tevatron.
hep-ph/0104130
Roberto Contino
Roberto Contino, Luigi Pilo
A Note on Regularization methods in Kaluza-Klein Theories
5 pages, 1 figure. v2: A minor comment corrected, conclusion unchanged. v3: A comment and a final note added. Version accepted for publication in Physics Letters B
Phys.Lett. B523 (2001) 347-350
10.1016/S0370-2693(01)01352-1
null
hep-ph
null
We comment on the presence of power-like divergences in Kaluza-Klein theories with supersymmetry breaking a l\`a Scherk-Schwarz. By introducing a SUSY preserving regulator, we show that, in the context of a recently model proposed by Barbieri, Hall and Nomura, the Higgs mass is finite and unambiguously defined. The same result applies to similar models.
[ { "created": "Thu, 12 Apr 2001 20:44:33 GMT", "version": "v1" }, { "created": "Fri, 18 May 2001 16:52:22 GMT", "version": "v2" }, { "created": "Fri, 19 Oct 2001 09:11:37 GMT", "version": "v3" } ]
2009-11-07
[ [ "Contino", "Roberto", "" ], [ "Pilo", "Luigi", "" ] ]
We comment on the presence of power-like divergences in Kaluza-Klein theories with supersymmetry breaking a l\`a Scherk-Schwarz. By introducing a SUSY preserving regulator, we show that, in the context of a recently model proposed by Barbieri, Hall and Nomura, the Higgs mass is finite and unambiguously defined. The same result applies to similar models.
1412.3798
Alfredo Urbano
Alfredo Urbano, Wei Xue
Constraining the Higgs portal with antiprotons
31 pages, 12 figures, 2 tables
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scalar Higgs portal is a compelling model of dark matter (DM) in which a renormalizable coupling with the Higgs boson provides the connection between the visible world and the dark sector. In this paper we investigate the constraint placed on the parameter space of this model by the antiproton data. Due to the fact that the antiproton-to-proton ratio has relative less systematic uncertainties than the antiproton absolute flux, we propose and explore the possibility to combine all the available $\bar{p}/p$ data. Following this approach, we are able to obtain stronger limits if compared with the existing literature. In particular, we show that most of the parameter space close to the Higgs resonance is ruled out by our analysis. Furthermore, by studying the reach of the future AMS-02 antiproton and antideuteron data, we argue that a DM mass of $\mathcal{O}(150)$ GeV offers a promising discovery potential. The method of combining all the antiproton-to-proton ratio data proposed in this paper is quite general, and can be straightforwardly applied to other models.
[ { "created": "Thu, 11 Dec 2014 20:59:58 GMT", "version": "v1" } ]
2014-12-12
[ [ "Urbano", "Alfredo", "" ], [ "Xue", "Wei", "" ] ]
The scalar Higgs portal is a compelling model of dark matter (DM) in which a renormalizable coupling with the Higgs boson provides the connection between the visible world and the dark sector. In this paper we investigate the constraint placed on the parameter space of this model by the antiproton data. Due to the fact that the antiproton-to-proton ratio has relative less systematic uncertainties than the antiproton absolute flux, we propose and explore the possibility to combine all the available $\bar{p}/p$ data. Following this approach, we are able to obtain stronger limits if compared with the existing literature. In particular, we show that most of the parameter space close to the Higgs resonance is ruled out by our analysis. Furthermore, by studying the reach of the future AMS-02 antiproton and antideuteron data, we argue that a DM mass of $\mathcal{O}(150)$ GeV offers a promising discovery potential. The method of combining all the antiproton-to-proton ratio data proposed in this paper is quite general, and can be straightforwardly applied to other models.
1612.06863
Luca Marzola
Laur J\"arv, Kristjan Kannike, Luca Marzola, Antonio Racioppi, Martti Raidal, Mihkel R\"unkla, Margus Saal, Hardi Veerm\"ae
A frame independent classification of single field inflationary models
7 pages; Added a paragraph on new directions in model building and modified the adopted notation. Matches the version to appear on PRL
Phys. Rev. Lett. 118, 151302 (2017)
10.1103/PhysRevLett.118.151302
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Seemingly unrelated models of inflation that originate from different physical setups yield, in some cases, identical predictions for the currently constrained inflationary observables. In order to classify the available models, we propose to express the slow-roll parameters and the relevant observables in terms of frame and reparametrisation invariant quantities. The adopted invariant formalism makes manifest the redundancy that afflicts the current description of inflation dynamics and offers a straightforward way to identify classes of models which yield identical phenomenology. In this Letter we offer a step-to-step recipe to recast every single field inflationary model in the proposed formalism, detailing also the procedure to compute inflationary observables in terms of frame and reparametrisation invariant quantities. We hope that our results become the cornerstone of a new categorisation of viable inflationary models and open the way to a deeper understanding of the inflation mechanism.
[ { "created": "Tue, 20 Dec 2016 21:00:02 GMT", "version": "v1" }, { "created": "Thu, 16 Mar 2017 07:39:15 GMT", "version": "v2" } ]
2017-04-19
[ [ "Järv", "Laur", "" ], [ "Kannike", "Kristjan", "" ], [ "Marzola", "Luca", "" ], [ "Racioppi", "Antonio", "" ], [ "Raidal", "Martti", "" ], [ "Rünkla", "Mihkel", "" ], [ "Saal", "Margus", "" ], [ "Veermäe", "Hardi", "" ] ]
Seemingly unrelated models of inflation that originate from different physical setups yield, in some cases, identical predictions for the currently constrained inflationary observables. In order to classify the available models, we propose to express the slow-roll parameters and the relevant observables in terms of frame and reparametrisation invariant quantities. The adopted invariant formalism makes manifest the redundancy that afflicts the current description of inflation dynamics and offers a straightforward way to identify classes of models which yield identical phenomenology. In this Letter we offer a step-to-step recipe to recast every single field inflationary model in the proposed formalism, detailing also the procedure to compute inflationary observables in terms of frame and reparametrisation invariant quantities. We hope that our results become the cornerstone of a new categorisation of viable inflationary models and open the way to a deeper understanding of the inflation mechanism.
2001.10737
Christian Bierlich
Christian Bierlich, Andy Buckley, Christian Holm Christensen, Peter Harald Lindenov Christiansen, Cody B. Duncan, Jan Fiete Grosse-Oetringhaus, Przemyslaw Karczmarczyk, Patrick Kirchgae{\ss}er, Jochen Klein, Leif L\"onnblad, Roberto Preghenella, Christine O. Rasmussen, Maria Stefaniak, and Vytautas Vislavicus
Confronting Experimental Data with Heavy-Ion Models: Rivet for Heavy Ions
31 pages, 12 figures
null
10.1140/epjc/s10052-020-8033-4
LU TP 20-04, MCNET-20-04
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Rivet library is an important toolkit in particle physics, and serves as a repository for analysis data and code. It allows for comparisons between data and theoretical calculations of the final state of collision events. This paper outlines several recent additions and improvements to the framework to include support for analysis of heavy ion collision simulated data. The paper also presents examples of these recent developments and their applicability in implementing concrete physics analyses.
[ { "created": "Wed, 29 Jan 2020 09:15:11 GMT", "version": "v1" } ]
2020-06-24
[ [ "Bierlich", "Christian", "" ], [ "Buckley", "Andy", "" ], [ "Christensen", "Christian Holm", "" ], [ "Christiansen", "Peter Harald Lindenov", "" ], [ "Duncan", "Cody B.", "" ], [ "Grosse-Oetringhaus", "Jan Fiete", "" ], [ "Karczmarczyk", "Przemyslaw", "" ], [ "Kirchgaeßer", "Patrick", "" ], [ "Klein", "Jochen", "" ], [ "Lönnblad", "Leif", "" ], [ "Preghenella", "Roberto", "" ], [ "Rasmussen", "Christine O.", "" ], [ "Stefaniak", "Maria", "" ], [ "Vislavicus", "Vytautas", "" ] ]
The Rivet library is an important toolkit in particle physics, and serves as a repository for analysis data and code. It allows for comparisons between data and theoretical calculations of the final state of collision events. This paper outlines several recent additions and improvements to the framework to include support for analysis of heavy ion collision simulated data. The paper also presents examples of these recent developments and their applicability in implementing concrete physics analyses.
1601.00913
Thomas E. Baker
Thomas E. Baker
Reproducing sterile neutrinos and the behavior of flavor oscillations with superconducting-magnetic proximity effects
16 pages, 7 figures
null
null
null
hep-ph astro-ph.HE cond-mat.supr-con
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The physics of a superconductor subjected to a magnetic field is known to be equivalent to neutrino oscillations. Examining the properties of singlet-triplet oscillations in the magnetic field, a sterile neutrino--shown to be a Majorana fermion--is suggested to be represented by singlet Cooper pairs and moderates flavor oscillations between three flavor neutrinos (triplet Cooper pairs). A superconductor-exchange spring system's rotating magnetization profile is used to simulate the mass-flavor oscillations in the neutrino case and the physics of neutrino oscillations are discussed. Symmetry protected triplet components are presented as weak process states. Phases acquired due to the Fulde-Ferrell-Larkin-Ovchinnikov effect produce a complex phase that may be responsible for charge-parity violation in flavor oscillations.
[ { "created": "Tue, 5 Jan 2016 17:31:12 GMT", "version": "v1" }, { "created": "Sun, 14 Feb 2016 22:11:22 GMT", "version": "v2" } ]
2016-02-16
[ [ "Baker", "Thomas E.", "" ] ]
The physics of a superconductor subjected to a magnetic field is known to be equivalent to neutrino oscillations. Examining the properties of singlet-triplet oscillations in the magnetic field, a sterile neutrino--shown to be a Majorana fermion--is suggested to be represented by singlet Cooper pairs and moderates flavor oscillations between three flavor neutrinos (triplet Cooper pairs). A superconductor-exchange spring system's rotating magnetization profile is used to simulate the mass-flavor oscillations in the neutrino case and the physics of neutrino oscillations are discussed. Symmetry protected triplet components are presented as weak process states. Phases acquired due to the Fulde-Ferrell-Larkin-Ovchinnikov effect produce a complex phase that may be responsible for charge-parity violation in flavor oscillations.
1607.03749
Zhi Xiao
Zhi Xiao
The Impact of Lorentz Violation on the Klein Tunneling Effect
3 pages, 1 figures, Presented at the Seventh Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 20-24, 2016
null
10.1103/PhysRevD.93.125022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the impact of a tiny Lorentz-violating $b^\mu$ term on the one dimensional motion of a Dirac particle scattering on a rectangular barrier. We assume the experiment is performed in a particular inertial frame, where the components of $b^\mu$ are assumed constants. The results show that Lorentz-violation modification to the transmission rate depends on the observer Lorentz nature of $b^\mu$. For a spacelike or lightlike $b^\mu$ the induced resonant frequency shift depends on the polarization, while for timelike $b^\mu$ there is essentially no modification.
[ { "created": "Tue, 12 Jul 2016 01:32:54 GMT", "version": "v1" } ]
2016-07-20
[ [ "Xiao", "Zhi", "" ] ]
We discuss the impact of a tiny Lorentz-violating $b^\mu$ term on the one dimensional motion of a Dirac particle scattering on a rectangular barrier. We assume the experiment is performed in a particular inertial frame, where the components of $b^\mu$ are assumed constants. The results show that Lorentz-violation modification to the transmission rate depends on the observer Lorentz nature of $b^\mu$. For a spacelike or lightlike $b^\mu$ the induced resonant frequency shift depends on the polarization, while for timelike $b^\mu$ there is essentially no modification.
hep-ph/0604194
Pavel Baikov
P.A. Baikov, K.G. Chetyrkin
Top Quark Mediated Higgs Decay into Hadrons to Order alpha(s)**5
4 pages, the final text published in Phys. Rev. Lett
Phys.Rev.Lett. 97 (2006) 061803
10.1103/PhysRevLett.97.061803
SFB/CPP-06-19, TTP06-14
hep-ph
null
We present in analytic form the O(alpha_s^5) correction to the H->gg partial width of the standard-model Higgs boson with intermediate mass M_H<2M_t. Its knowledge is useful because the O(alpha_s^4) correction is sizeable (around 20%). For M_H=120 GeV, the resulting QCD correction factor reads 1 + (215/12) alpha_s^(5)(M_H)/pi + 152.5 (alpha_s^(5)(M_H)/pi)^2 + 381.5 (alpha_s^(5)(M_H)/pi)^3 \approx 1+0.65+0.20+0.02. The new four-loop correction increases the total Higgs-boson hadronic width by a small amount of order 1 promille and stabilizes significantly the residual scale dependence.
[ { "created": "Sat, 22 Apr 2006 16:28:01 GMT", "version": "v1" }, { "created": "Thu, 28 Sep 2006 16:16:07 GMT", "version": "v2" } ]
2016-09-06
[ [ "Baikov", "P. A.", "" ], [ "Chetyrkin", "K. G.", "" ] ]
We present in analytic form the O(alpha_s^5) correction to the H->gg partial width of the standard-model Higgs boson with intermediate mass M_H<2M_t. Its knowledge is useful because the O(alpha_s^4) correction is sizeable (around 20%). For M_H=120 GeV, the resulting QCD correction factor reads 1 + (215/12) alpha_s^(5)(M_H)/pi + 152.5 (alpha_s^(5)(M_H)/pi)^2 + 381.5 (alpha_s^(5)(M_H)/pi)^3 \approx 1+0.65+0.20+0.02. The new four-loop correction increases the total Higgs-boson hadronic width by a small amount of order 1 promille and stabilizes significantly the residual scale dependence.
hep-ph/0203188
Josephine Bolosan
Sandip Pakvasa and Probir Roy
Constraining four neutrino mass patterns from neutrinoless double beta decay
One equation and three entries in a table have been changed, some typographical errors corrected and a few references added. The basic conclusions are not changed. To be published in Physics Letters. B., 9 pages, 4 figures
Phys.Lett. B535 (2002) 181-186
10.1016/S0370-2693(02)01763-X
UH511-996-02
hep-ph astro-ph hep-ex
null
All existing data on neutrino oscillations (including those from the LSND experiment) imply a four neutrino scheme with six different allowed mass patterns. Some of the latter are shown to be disfavored by using a conservative upper bound on the $\beta beta 0 \nu$ nuclear decay rate, if neutrinos are assumed to be Majorana particles. Comparisons are also made with restrictions from tritium $\beta$-decay and cosmology.
[ { "created": "Tue, 19 Mar 2002 21:57:55 GMT", "version": "v1" }, { "created": "Fri, 19 Apr 2002 21:51:10 GMT", "version": "v2" } ]
2009-11-07
[ [ "Pakvasa", "Sandip", "" ], [ "Roy", "Probir", "" ] ]
All existing data on neutrino oscillations (including those from the LSND experiment) imply a four neutrino scheme with six different allowed mass patterns. Some of the latter are shown to be disfavored by using a conservative upper bound on the $\beta beta 0 \nu$ nuclear decay rate, if neutrinos are assumed to be Majorana particles. Comparisons are also made with restrictions from tritium $\beta$-decay and cosmology.
1007.1835
Joerg Jaeckel
O.K. Baker, G. Cantatore, J. Jaeckel and G. Mueller
Notes from the 3rd Axion Strategy Meeting
5 pages, 1 figure
AIP Conf.Proc.1274:175-179,2010
10.1063/1.3489551
DCPT/10/110; IPPP/10/55
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note we briefly summarize the main future targets and strategies for axion and general low energy particle physics identified in the "3rd axion strategy meeting" held during the AXIONS 2010 workshop. This summary follows a wide discussion with contributions from many of the workshop attendees.
[ { "created": "Mon, 12 Jul 2010 07:21:30 GMT", "version": "v1" } ]
2014-11-21
[ [ "Baker", "O. K.", "" ], [ "Cantatore", "G.", "" ], [ "Jaeckel", "J.", "" ], [ "Mueller", "G.", "" ] ]
In this note we briefly summarize the main future targets and strategies for axion and general low energy particle physics identified in the "3rd axion strategy meeting" held during the AXIONS 2010 workshop. This summary follows a wide discussion with contributions from many of the workshop attendees.
1201.6287
Kei Yagyu
Shinya Kanemura, Kei Yagyu
Radiative corrections to electroweak parameters in the Higgs triplet model and implication with the recent Higgs boson searches
17 pages, 23 figures, version published in PRD, title slightly modified
null
10.1103/PhysRevD.85.115009
UT-HET 064
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study radiative corrections to the electroweak parameters in the Higgs model with the Y=1 triplet field, which is introduced in the scenario of generating neutrino masses based on the so-called type II seesaw mechanism. In this model, the rho parameter deviates from unity at the tree level. Consequently, the electroweak sector of the model is described by the four input parameters such as $\alpha_{\text{em}}$, $G_F$, $m_Z$ and $\sin^2\theta_W$. We calculate the one loop contribution to the W boson mass as well as to the rho parameter in order to clarify the possible mass spectrum of the extra Higgs bosons under the constraint from the electroweak precision data. We find that the hierarchical mass spectrum among $H^{\pm\pm}$, $H^{\pm}$ and $A$ (or $H$) is favored by the precision data especially for the case of $m_A$ $(\simeq m_H)>m_{H^+}>m_{H^{++}}$, where $H^{\pm\pm}$, $H^{\pm}$, $A$ and $H$ are the doubly-charged, singly-charged, CP-odd and CP-even Higgs bosons mainly originated from the triplet field. We also discuss phenomenological consequences of such a mass spectrum with relatively large mass splitting. The decay rate of the Higgs boson decay into two photons is evaluated under the constraint from the electroweak precision data, regarding the recent Higgs boson searches at the CERN LHC.
[ { "created": "Mon, 30 Jan 2012 17:20:09 GMT", "version": "v1" }, { "created": "Wed, 6 Jun 2012 04:54:48 GMT", "version": "v2" } ]
2015-06-04
[ [ "Kanemura", "Shinya", "" ], [ "Yagyu", "Kei", "" ] ]
We study radiative corrections to the electroweak parameters in the Higgs model with the Y=1 triplet field, which is introduced in the scenario of generating neutrino masses based on the so-called type II seesaw mechanism. In this model, the rho parameter deviates from unity at the tree level. Consequently, the electroweak sector of the model is described by the four input parameters such as $\alpha_{\text{em}}$, $G_F$, $m_Z$ and $\sin^2\theta_W$. We calculate the one loop contribution to the W boson mass as well as to the rho parameter in order to clarify the possible mass spectrum of the extra Higgs bosons under the constraint from the electroweak precision data. We find that the hierarchical mass spectrum among $H^{\pm\pm}$, $H^{\pm}$ and $A$ (or $H$) is favored by the precision data especially for the case of $m_A$ $(\simeq m_H)>m_{H^+}>m_{H^{++}}$, where $H^{\pm\pm}$, $H^{\pm}$, $A$ and $H$ are the doubly-charged, singly-charged, CP-odd and CP-even Higgs bosons mainly originated from the triplet field. We also discuss phenomenological consequences of such a mass spectrum with relatively large mass splitting. The decay rate of the Higgs boson decay into two photons is evaluated under the constraint from the electroweak precision data, regarding the recent Higgs boson searches at the CERN LHC.
2003.10416
Oscar Mac\'ias
Kevork N. Abazajian, Shunsaku Horiuchi, Manoj Kaplinghat, Ryan E. Keeley and Oscar Macias
Strong constraints on thermal relic dark matter from Fermi-LAT observations of the Galactic Center
23 pages, 14 figures. V2: more IC rings included, profile likelihood corrected, more tests added; main results and conclusions unchanged. V3: corrected typo found in Tab. II. Matches version published in PRD
Phys. Rev. D 102, 043012 (2020)
10.1103/PhysRevD.102.043012
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The extended excess toward the Galactic Center (GC) in gamma rays inferred from Fermi-LAT observations has been interpreted as being due to dark matter (DM) annihilation. Here, we perform new likelihood analyses of the GC and show that, when including templates for the stellar galactic and nuclear bulges, the GC shows no significant detection of a DM annihilation template, even after generous variations in the Galactic diffuse emission models and a wide range of DM halo profiles. We include Galactic diffuse emission models with combinations of three-dimensional inverse Compton maps, variations of interstellar gas maps, and a central source of electrons. For the DM profile, we include both spherical and ellipsoidal DM morphologies and a range of radial profiles from steep cusps to kiloparsec-sized cores, motivated in part by hydrodynamical simulations. Our derived upper limits on the dark matter annihilation flux place strong constraints on DM properties. In the case of the pure $b$-quark annihilation channel, our limits on the annihilation cross section are more stringent than those from the Milky Way dwarfs up to DM masses of approximately TeV and rule out the thermal relic cross section up to approximately 300 GeV. Better understanding of the DM profile, as well as the Fermi-LAT data at its highest energies, would further improve the sensitivity to DM properties.
[ { "created": "Mon, 23 Mar 2020 17:44:40 GMT", "version": "v1" }, { "created": "Thu, 20 Aug 2020 18:41:55 GMT", "version": "v2" }, { "created": "Mon, 25 Jan 2021 20:53:04 GMT", "version": "v3" } ]
2021-01-27
[ [ "Abazajian", "Kevork N.", "" ], [ "Horiuchi", "Shunsaku", "" ], [ "Kaplinghat", "Manoj", "" ], [ "Keeley", "Ryan E.", "" ], [ "Macias", "Oscar", "" ] ]
The extended excess toward the Galactic Center (GC) in gamma rays inferred from Fermi-LAT observations has been interpreted as being due to dark matter (DM) annihilation. Here, we perform new likelihood analyses of the GC and show that, when including templates for the stellar galactic and nuclear bulges, the GC shows no significant detection of a DM annihilation template, even after generous variations in the Galactic diffuse emission models and a wide range of DM halo profiles. We include Galactic diffuse emission models with combinations of three-dimensional inverse Compton maps, variations of interstellar gas maps, and a central source of electrons. For the DM profile, we include both spherical and ellipsoidal DM morphologies and a range of radial profiles from steep cusps to kiloparsec-sized cores, motivated in part by hydrodynamical simulations. Our derived upper limits on the dark matter annihilation flux place strong constraints on DM properties. In the case of the pure $b$-quark annihilation channel, our limits on the annihilation cross section are more stringent than those from the Milky Way dwarfs up to DM masses of approximately TeV and rule out the thermal relic cross section up to approximately 300 GeV. Better understanding of the DM profile, as well as the Fermi-LAT data at its highest energies, would further improve the sensitivity to DM properties.
1201.5580
J.D. Vergados
J.D. Vergados (Physics Department, University of Ioannina, Ioannina, Greece)
Predicted rates for direct WIMP searches
8 pages, 2 tables,6 figures. To appear in the proceedings of the workshop "The Dark Side of the Universe (DSU 2011)" organized by KITPC, Beijing, September 26-30, 2011
null
10.1088/1742-6596/384/1/012023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The differential event rate for direct detection of dark matter, both the time averaged and the modulated one due to the motion of the Earth, are discussed. The calculations focus on relatively light cold dark matter candidates (WIMP) and low energy transfers. It is shown that for some WIMP masses the modulation amplitude may change sign. This effect can be exploited to yield information about the mass of the dark matter candidate.
[ { "created": "Thu, 26 Jan 2012 17:05:34 GMT", "version": "v1" } ]
2015-06-03
[ [ "Vergados", "J. D.", "", "Physics Department, University of Ioannina, Ioannina,\n Greece" ] ]
The differential event rate for direct detection of dark matter, both the time averaged and the modulated one due to the motion of the Earth, are discussed. The calculations focus on relatively light cold dark matter candidates (WIMP) and low energy transfers. It is shown that for some WIMP masses the modulation amplitude may change sign. This effect can be exploited to yield information about the mass of the dark matter candidate.
hep-ph/9806324
Tom Steele
V. Elias, T. G. Steele, F. Chishtie, R. Migneron and K. Sprague
Pade-Improvement of QCD Running Coupling Constants, Running Masses, Higgs Decay Rates, and Scalar Channel Sum Rules
latex, 22 pages, 8 figures, references corrected
Phys.Rev. D58 (1998) 116007
10.1103/PhysRevD.58.116007
null
hep-ph
null
We discuss Pad\'e-improvement of known four-loop order results based upon an asymptotic three-parameter error formula for Pad\'e-approximants. We derive an explicit formula estimating the next-order coefficient $R_4$ from the previous coefficients in a series $1+R_1 x + R_2x^2 + R_3x^3$. We show that such an estimate is within 0.18% of the known five-loop order term in the O(1) $\beta$-function, and within 10% of the known five-loop term in the O(1) anomalous mass-dimension function $\gamma_m(g)$. We apply the same formula to generate a [2$|$2] Pad\'e-summation of the QCD $\beta$-function and anomalous mass dimension in order to demonstrate both the relative insensitivity of the evolution of $\alpha_s(\mu)$ and the running quark masses to higher order corrections, as well as a somewhat increased compatibility of the present empirical range for $\alpha_s(m_\tau)$ with the range anticipated via evolution from the present empirical range for $\alpha_s(M_z)$. For $3 \leq n_f \leq 6$ we demonstrate that positive zeros of any [2$|$2] Pad\'e-summation estimate of the all-orders $\beta$-function which incorporates known two-, three-, and four-loop contributions necessarily correspond to ultraviolet fixed points, regardless of the unknown five-loop term. Pad\'e-improvement of higher-order perturbative expressions is presented for the decay rates of the Higgs into two gluons and into a $b \bar{b}$ pair, and is used to show the relative insensitivity of these rates to higher order effects. However, Pad\'e-improvement of the purely-perturbative component of scalar/pseudoscalar current correlation functions is indicative of large theoretical uncertainties in QCD sum rules for these channels, particularly if the continuum-threshold parameter $s_0$ is near 1 GeV$^2$.
[ { "created": "Tue, 9 Jun 1998 19:47:12 GMT", "version": "v1" }, { "created": "Thu, 11 Jun 1998 16:12:58 GMT", "version": "v2" }, { "created": "Fri, 12 Jun 1998 15:07:15 GMT", "version": "v3" } ]
2009-10-31
[ [ "Elias", "V.", "" ], [ "Steele", "T. G.", "" ], [ "Chishtie", "F.", "" ], [ "Migneron", "R.", "" ], [ "Sprague", "K.", "" ] ]
We discuss Pad\'e-improvement of known four-loop order results based upon an asymptotic three-parameter error formula for Pad\'e-approximants. We derive an explicit formula estimating the next-order coefficient $R_4$ from the previous coefficients in a series $1+R_1 x + R_2x^2 + R_3x^3$. We show that such an estimate is within 0.18% of the known five-loop order term in the O(1) $\beta$-function, and within 10% of the known five-loop term in the O(1) anomalous mass-dimension function $\gamma_m(g)$. We apply the same formula to generate a [2$|$2] Pad\'e-summation of the QCD $\beta$-function and anomalous mass dimension in order to demonstrate both the relative insensitivity of the evolution of $\alpha_s(\mu)$ and the running quark masses to higher order corrections, as well as a somewhat increased compatibility of the present empirical range for $\alpha_s(m_\tau)$ with the range anticipated via evolution from the present empirical range for $\alpha_s(M_z)$. For $3 \leq n_f \leq 6$ we demonstrate that positive zeros of any [2$|$2] Pad\'e-summation estimate of the all-orders $\beta$-function which incorporates known two-, three-, and four-loop contributions necessarily correspond to ultraviolet fixed points, regardless of the unknown five-loop term. Pad\'e-improvement of higher-order perturbative expressions is presented for the decay rates of the Higgs into two gluons and into a $b \bar{b}$ pair, and is used to show the relative insensitivity of these rates to higher order effects. However, Pad\'e-improvement of the purely-perturbative component of scalar/pseudoscalar current correlation functions is indicative of large theoretical uncertainties in QCD sum rules for these channels, particularly if the continuum-threshold parameter $s_0$ is near 1 GeV$^2$.
1506.06542
Go Mishima
Y. Kiyo, G. Mishima, Y. Sumino
Strong IR Cancellation in Heavy Quarkonium and Precise Top Mass Determination
17 pages, 7 figures, 3 tables; Revisions in ver.2: We added (i) a more conservative error estimate of m_t determination, (ii) discussion on u=+1 and u=-1 renormalons, (iii) interpretation of PS-scheme
JHEP 11 084 (2015)
10.1007/JHEP11(2015)084
TU-997, UT-15-20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Combining recent perturbative analyses on the static QCD potential and the quark pole mass, we find that, for the heavy quarkonium states $c\bar{c}$, $b\bar{b}$ and $t\bar{t}$, (1) ultra-soft (US) corrections in the binding energies are small, and (2) there is a stronger cancellation of IR contributions than what has been predicted by renormalon dominance hypothesis. By contrast, for a hypothetical heavy quarkonium system with a small number of active quark flavors ($n_l\approx 0$), we observe evidence that renormalon dominance holds accurately and that non-negligible contributions from US corrections exist. In addition, we examine contributions of renormalons at $u=- 1$. As an important consequence, we improve on a previous prediction for possible achievable accuracy of top quark $\overline{\rm MS}$--mass measurement at a future linear collider and estimate that in principle 20--30~MeV accuracy is reachable.
[ { "created": "Mon, 22 Jun 2015 10:36:27 GMT", "version": "v1" }, { "created": "Thu, 19 Nov 2015 16:51:21 GMT", "version": "v2" } ]
2015-11-20
[ [ "Kiyo", "Y.", "" ], [ "Mishima", "G.", "" ], [ "Sumino", "Y.", "" ] ]
Combining recent perturbative analyses on the static QCD potential and the quark pole mass, we find that, for the heavy quarkonium states $c\bar{c}$, $b\bar{b}$ and $t\bar{t}$, (1) ultra-soft (US) corrections in the binding energies are small, and (2) there is a stronger cancellation of IR contributions than what has been predicted by renormalon dominance hypothesis. By contrast, for a hypothetical heavy quarkonium system with a small number of active quark flavors ($n_l\approx 0$), we observe evidence that renormalon dominance holds accurately and that non-negligible contributions from US corrections exist. In addition, we examine contributions of renormalons at $u=- 1$. As an important consequence, we improve on a previous prediction for possible achievable accuracy of top quark $\overline{\rm MS}$--mass measurement at a future linear collider and estimate that in principle 20--30~MeV accuracy is reachable.
1103.4613
Francisco Campanario
G. Bozzi, F. Campanario, M. Rauch and D. Zeppenfeld
W\gamma \gamma production with leptonic decays at NLO QCD
18 pages, 13 figures
Phys.Rev.D83:114035,2011
10.1103/PhysRevD.83.114035
FTUV-11-0324,IFUM-971-FT,KA-TP-08--2011,LPN11-14,SFB/CPP-11-14
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The computation of the NLO-QCD corrections to the cross sections for W \gamma \gamma production in hadronic collisions is presented. We consider the case of real photons in the final state, but include full leptonic decays of the W. Numerical results for the LHC and the Tevatron are obtained through a parton level Monte Carlo based on the structure of the VBFNLO program, allowing an easy implementation of general cuts and distributions. We show the dependence on scale variations of the integrated cross sections and provide evidence of the fact that NLO QCD corrections strongly modify the LO predictions for observables at the LHC both in magnitude and in shape.
[ { "created": "Wed, 23 Mar 2011 20:00:09 GMT", "version": "v1" } ]
2011-07-05
[ [ "Bozzi", "G.", "" ], [ "Campanario", "F.", "" ], [ "Rauch", "M.", "" ], [ "Zeppenfeld", "D.", "" ] ]
The computation of the NLO-QCD corrections to the cross sections for W \gamma \gamma production in hadronic collisions is presented. We consider the case of real photons in the final state, but include full leptonic decays of the W. Numerical results for the LHC and the Tevatron are obtained through a parton level Monte Carlo based on the structure of the VBFNLO program, allowing an easy implementation of general cuts and distributions. We show the dependence on scale variations of the integrated cross sections and provide evidence of the fact that NLO QCD corrections strongly modify the LO predictions for observables at the LHC both in magnitude and in shape.
1111.5643
Giovanni Amelino-Camelia
Giovanni Amelino-Camelia
Particle-dependent deformations of Lorentz symmetry
v2: added one more example of conservation law for interactions involving particles with different relativistic properties
null
null
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I here investigate what is arguably the most significant residual challenge for the proposal of phenomenologically viable "DSR deformations" of relativistic kinematics, which concerns the description of composite particles, such as atoms. In some approaches to the formalization of possible scenarios for DSR-deformation of Lorentz symmetry it emerges that composite particles should have relativistic properties different from the ones of their constituent "fundamental particles", but these previous results provided no clue as to how the mismatch of relativistic properties could be consistently implemented. I show that it is possible to implement a fully consistent DSR-relativistic description of kinematics endowing different types of particles with suitably different deformed-Lorentz-symmetry properties. I also contemplate the possibility that some types of particles (or macroscopic bodies) behave according to completely undeformed special relativity, which in particular might apply to the DSR description of the macroscopic bodies that constitute measuring devices ("observers"). The formalization is also applicable to cases where different fundamental particles have different relativistic properties, leading to a type of phenomenology which I illustrate by considering possible applications to the ongoing analyses of the "Lorentz-symmetry anomaly" that was recently tentatively reported by the OPERA collaboration. Some of the new elements here introduced in the formulation of relativistic kinematics appear to also provide the starting point for the development of a correspondingly novel mathematical formulation of spacetime-symmetry algebras.
[ { "created": "Wed, 23 Nov 2011 22:42:19 GMT", "version": "v1" }, { "created": "Wed, 14 Dec 2011 17:11:21 GMT", "version": "v2" } ]
2011-12-15
[ [ "Amelino-Camelia", "Giovanni", "" ] ]
I here investigate what is arguably the most significant residual challenge for the proposal of phenomenologically viable "DSR deformations" of relativistic kinematics, which concerns the description of composite particles, such as atoms. In some approaches to the formalization of possible scenarios for DSR-deformation of Lorentz symmetry it emerges that composite particles should have relativistic properties different from the ones of their constituent "fundamental particles", but these previous results provided no clue as to how the mismatch of relativistic properties could be consistently implemented. I show that it is possible to implement a fully consistent DSR-relativistic description of kinematics endowing different types of particles with suitably different deformed-Lorentz-symmetry properties. I also contemplate the possibility that some types of particles (or macroscopic bodies) behave according to completely undeformed special relativity, which in particular might apply to the DSR description of the macroscopic bodies that constitute measuring devices ("observers"). The formalization is also applicable to cases where different fundamental particles have different relativistic properties, leading to a type of phenomenology which I illustrate by considering possible applications to the ongoing analyses of the "Lorentz-symmetry anomaly" that was recently tentatively reported by the OPERA collaboration. Some of the new elements here introduced in the formulation of relativistic kinematics appear to also provide the starting point for the development of a correspondingly novel mathematical formulation of spacetime-symmetry algebras.
1712.05180
Laura Duarte
Alexandre Alves, M. Dias, F. de Campos, L. Duarte, J. M. Hoff da Silva
Constraining Elko Dark Matter at the LHC with Monophoton Events
6 pages, 4 figures
null
10.1209/0295-5075/121/31001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A mass dimension one fermion, also known as Elko, constitutes a dark matter candidate which might interact with photons at the tree level in a specific fashion. In this work, we investigate the constraints imposed by unitarity and LHC data on this type of interactions using the search for new physics in monophoton events. We found that Elkos which can explain the dark matter relic abundance mainly through electromagnetic interactions are excluded at the 95\%CL by the 8 TeV LHC data for masses up to 1 TeV.
[ { "created": "Thu, 14 Dec 2017 11:36:04 GMT", "version": "v1" } ]
2018-04-18
[ [ "Alves", "Alexandre", "" ], [ "Dias", "M.", "" ], [ "de Campos", "F.", "" ], [ "Duarte", "L.", "" ], [ "da Silva", "J. M. Hoff", "" ] ]
A mass dimension one fermion, also known as Elko, constitutes a dark matter candidate which might interact with photons at the tree level in a specific fashion. In this work, we investigate the constraints imposed by unitarity and LHC data on this type of interactions using the search for new physics in monophoton events. We found that Elkos which can explain the dark matter relic abundance mainly through electromagnetic interactions are excluded at the 95\%CL by the 8 TeV LHC data for masses up to 1 TeV.
2106.15945
Vivek Kumar Nautiyal
Vivek Kumar Nautiyal, Bipin Singh Koranga, Ashish Shrivastava, Neelam Das
Matter Effects on Mass Square Difference for Four Flavor Neutrino Oscillation
7 pages, 1 figures, 5 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider the matter effects on four flavor neutrino oscillation scheme (3+1). In presence of sterile neutrino, the simplest four flavor neutrino mixing there are six mixing angles and three Dirac CP phases. In this paper, we discuss about the sensitivity of mass square difference effects Delta21, Delta31, and Delta41 in the matter. We find that in presence of sterile neutrino for four flavor mixing framework, only solar mass square difference Delta21 and atmospheric neutrino mass square difference Delta31 change for different values of Dirac phases and energy. There is no change of sterile neutrino mass square differences. In this letter, we study the matter effects on neutrino mass square differences Delta21, Delta31, and Delta41 and calculate the percentage change with respect to the mass square difference in the matter by varying energy for four flavor framework.
[ { "created": "Wed, 30 Jun 2021 09:54:06 GMT", "version": "v1" } ]
2021-07-01
[ [ "Nautiyal", "Vivek Kumar", "" ], [ "Koranga", "Bipin Singh", "" ], [ "Shrivastava", "Ashish", "" ], [ "Das", "Neelam", "" ] ]
We consider the matter effects on four flavor neutrino oscillation scheme (3+1). In presence of sterile neutrino, the simplest four flavor neutrino mixing there are six mixing angles and three Dirac CP phases. In this paper, we discuss about the sensitivity of mass square difference effects Delta21, Delta31, and Delta41 in the matter. We find that in presence of sterile neutrino for four flavor mixing framework, only solar mass square difference Delta21 and atmospheric neutrino mass square difference Delta31 change for different values of Dirac phases and energy. There is no change of sterile neutrino mass square differences. In this letter, we study the matter effects on neutrino mass square differences Delta21, Delta31, and Delta41 and calculate the percentage change with respect to the mass square difference in the matter by varying energy for four flavor framework.
hep-ph/9703350
null
K.-I. Izawa and T. Yanagida
R-invariant Natural Unification
14 pages, latex
Prog.Theor.Phys. 97 (1997) 913-920
10.1143/PTP.97.913
UT-770
hep-ph
null
We construct R-invariant unification models where a pair of massless Higgs doublets is naturally obtained. The masslessness of the Higgs doublets is guaranteed by the unbroken R symmetry. Mass generation for the Higgs doublets is considered from various viewpoints.
[ { "created": "Tue, 18 Mar 1997 06:57:01 GMT", "version": "v1" } ]
2009-10-30
[ [ "Izawa", "K. -I.", "" ], [ "Yanagida", "T.", "" ] ]
We construct R-invariant unification models where a pair of massless Higgs doublets is naturally obtained. The masslessness of the Higgs doublets is guaranteed by the unbroken R symmetry. Mass generation for the Higgs doublets is considered from various viewpoints.
2011.13685
Priyank Parashari
Arindam Mazumdar, Subhendra Mohanty, Priyank Parashari
Flavour specific neutrino self-interaction: $H_0$ tension and IceCube
25 Pages, 10 figures, 7 tables, matches the version published in JCAP
null
10.1088/1475-7516/2022/10/011
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Self-interaction in the active neutrinos is studied in the literature to alleviate the $H_0$ tension. Similar self-interaction can also explain the observed dips in the flux of the neutrinos coming from the distant astro-physical sources in IceCube detectors. In contrast to the flavour universal neutrino interaction considered for solving the $H_0$ tension, which is ruled out from particle physics experiments, we consider flavour specific neutrino interactions. We show that the values of self-interaction coupling constant and mediator mass required for explaining the IceCube dips are inconsistent with the strong neutrino self-interactions preferred by the combination of BAO, HST and Planck data. However, the required amount of self-interaction between tau neutrinos ($\nu_\tau$) in inverted hierarchy for explaining IceCube dips is consistent with the moderate self-interaction region of cosmological bounds at 1-$\sigma$ level. For the case of other interactions and hierarchies, the IceCube preferred amount of self-interaction is consistent with moderate self-interaction region of cosmological bounds at 2-$\sigma$ level only.
[ { "created": "Fri, 27 Nov 2020 11:51:21 GMT", "version": "v1" }, { "created": "Mon, 11 Jan 2021 17:47:52 GMT", "version": "v2" }, { "created": "Mon, 28 Nov 2022 14:02:14 GMT", "version": "v3" } ]
2022-11-29
[ [ "Mazumdar", "Arindam", "" ], [ "Mohanty", "Subhendra", "" ], [ "Parashari", "Priyank", "" ] ]
Self-interaction in the active neutrinos is studied in the literature to alleviate the $H_0$ tension. Similar self-interaction can also explain the observed dips in the flux of the neutrinos coming from the distant astro-physical sources in IceCube detectors. In contrast to the flavour universal neutrino interaction considered for solving the $H_0$ tension, which is ruled out from particle physics experiments, we consider flavour specific neutrino interactions. We show that the values of self-interaction coupling constant and mediator mass required for explaining the IceCube dips are inconsistent with the strong neutrino self-interactions preferred by the combination of BAO, HST and Planck data. However, the required amount of self-interaction between tau neutrinos ($\nu_\tau$) in inverted hierarchy for explaining IceCube dips is consistent with the moderate self-interaction region of cosmological bounds at 1-$\sigma$ level. For the case of other interactions and hierarchies, the IceCube preferred amount of self-interaction is consistent with moderate self-interaction region of cosmological bounds at 2-$\sigma$ level only.
hep-ph/9805245
Andrzej Rostworowski
Michal Praszalowicz (1,2), Andrzej Rostworowski (2) ((1) Ruhr-University Bochum, (2) Jagellonian University Krakow)
Spectrum of the Odderon Charge for Arbitrary Conformal Weights
10 pages, 3 figures
Acta Phys.Polon. B30 (1999) 349-357
null
TPJU-8/98
hep-ph
null
The odderon equation is studied in terms of the variable suggested by the modular invariance of the 3 Reggeon system. Odderon charge is identified with the cross-product of three conformal spins. A complete set of commuting operators: h^2 and q is diagonalized and quantization conditions for eigenvalues of the odderon charge q are solved for arbitrary conformal weight h.
[ { "created": "Thu, 7 May 1998 09:49:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Praszalowicz", "Michal", "" ], [ "Rostworowski", "Andrzej", "" ] ]
The odderon equation is studied in terms of the variable suggested by the modular invariance of the 3 Reggeon system. Odderon charge is identified with the cross-product of three conformal spins. A complete set of commuting operators: h^2 and q is diagonalized and quantization conditions for eigenvalues of the odderon charge q are solved for arbitrary conformal weight h.
0810.0409
Jonathan Butterworth
Jonathan M. Butterworth, Adam R. Davison, Mathieu Rubin, Gavin P. Salam
Jet substructure as a new Higgs search channel at the Large Hadron Collider
Talk presented by J.M.Butterworth at 34th International Conference on High Energy Physics, ICHEP08, Philadelphia, July 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that W H and Z H production where the Higgs boson decays to bbbar can be recovered as good search channels for the Standard Model Higgs at the Large Hadron Collider. This is done by requiring the Higgs to have high transverse momentum, and employing state-of-the-art jet reconstruction and decomposition techniques.
[ { "created": "Thu, 2 Oct 2008 13:07:20 GMT", "version": "v1" } ]
2008-10-03
[ [ "Butterworth", "Jonathan M.", "" ], [ "Davison", "Adam R.", "" ], [ "Rubin", "Mathieu", "" ], [ "Salam", "Gavin P.", "" ] ]
We show that W H and Z H production where the Higgs boson decays to bbbar can be recovered as good search channels for the Standard Model Higgs at the Large Hadron Collider. This is done by requiring the Higgs to have high transverse momentum, and employing state-of-the-art jet reconstruction and decomposition techniques.
1211.5539
Vladimir Saleev
M. A. Nefedov, N. N. Nikolaev, V. A. Saleev
Drell-Yan lepton pair production at high energies in the Parton Reggeization Approach
16 pages, 11 figures
Phys.Rev. D87 (2013) 014022
10.1103/PhysRevD.87.014022
DESY 12-220
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
According to extensive theoretical studies of the high energy limit of QCD, inelastic interactions are dominated by the multi-Regge final states. The appropriate gauge-invariant objects, which simultaneously incorporate the transverse momentum degrees of freedom, are Reggeized gluons, quarks and antiquarks. In the present communication we extend parton Reggeization approach to Drell-Yan production of massive lepton pairs. The basic ingredient is a process of Reggeized quark-antiquark annihilation, which is described by the Reggeon-Reggeon-photon effective vertex. We calculate transverse-momentum and invariant-mass distributions of Drell-Yan lepton pairs measured at the CERN SPS, FNAL Tevatron and CERN LHC in the different ranges of energy and rapidity. We focus on angular distributions of Drell-Yan leptons in different kinematical ranges. The obtained results are compared with the existing data and a good agreement is found. The predictions for future experiments for Drell-Yan lepton pair production at the CERN LHC have been made.
[ { "created": "Fri, 23 Nov 2012 16:24:00 GMT", "version": "v1" }, { "created": "Tue, 27 Nov 2012 10:52:28 GMT", "version": "v2" } ]
2013-04-22
[ [ "Nefedov", "M. A.", "" ], [ "Nikolaev", "N. N.", "" ], [ "Saleev", "V. A.", "" ] ]
According to extensive theoretical studies of the high energy limit of QCD, inelastic interactions are dominated by the multi-Regge final states. The appropriate gauge-invariant objects, which simultaneously incorporate the transverse momentum degrees of freedom, are Reggeized gluons, quarks and antiquarks. In the present communication we extend parton Reggeization approach to Drell-Yan production of massive lepton pairs. The basic ingredient is a process of Reggeized quark-antiquark annihilation, which is described by the Reggeon-Reggeon-photon effective vertex. We calculate transverse-momentum and invariant-mass distributions of Drell-Yan lepton pairs measured at the CERN SPS, FNAL Tevatron and CERN LHC in the different ranges of energy and rapidity. We focus on angular distributions of Drell-Yan leptons in different kinematical ranges. The obtained results are compared with the existing data and a good agreement is found. The predictions for future experiments for Drell-Yan lepton pair production at the CERN LHC have been made.
hep-ph/9606324
Ahmed Ali
A. Ali (DESY, Hamburg)
$B$ Decays, Flavour Mixings and CP Violation in the Standard Model
87 pages, 15 figures (require epsf.sty, rotate, epsf bounding box macro embedded). Five lectures presented at the XX International Nathiagali Summer College on Physics and Contemporary Needs, Bhurban, Pakistan, June 24 - July 11, 1995; to be published in the Proceedings (Nova Science Publishers, New York). Dedicated to Professor Abdus Salam on his 70th Birthday. Report No. DESY 96-106, June 1996
null
null
null
hep-ph
null
These lectures review the progress made in our present understanding of $B$ decays. The emphasis here is on applications of QCD to $B$ decays and the attendant perturbative and non-perturbative uncertainties, which limit present theoretical precision in some cases but the overall picture that emerges is consistent with the standard model (SM). This is illustrated by quantitatively analyzing some of the key measurements in $B$ physics.
[ { "created": "Thu, 13 Jun 1996 16:18:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ali", "A.", "", "DESY, Hamburg" ] ]
These lectures review the progress made in our present understanding of $B$ decays. The emphasis here is on applications of QCD to $B$ decays and the attendant perturbative and non-perturbative uncertainties, which limit present theoretical precision in some cases but the overall picture that emerges is consistent with the standard model (SM). This is illustrated by quantitatively analyzing some of the key measurements in $B$ physics.
2407.12738
Yongchao Zhang
P. S. Bhupal Dev, Doojin Kim, Deepak Sathyan, Kuver Sinha, Yongchao Zhang
New Laboratory Constraints on Neutrinophilic Mediators
7+3 pages, 4+0 figures and 0+1 table
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Neutrinophilic mediators are well-motivated messenger particles that can probe some of the least known sectors of fundamental physics involving nonstandard interactions of neutrinos with themselves and potentially with dark matter. In particular, light mediators coupling to the active neutrinos will induce new decay modes of the Standard Model mesons (e.g., $\pi^\pm, K^\pm \to \ell^\pm + \nu + \phi$), charged leptons (e.g., $\tau^\pm \to \pi^\pm + \nu + \phi$), and gauge bosons (e.g., $Z \to \nu + \bar{\nu} + \phi$). A common lore is that these decays suffer from infrared divergences in the limit of the vanishing mediator mass, i.e., $m_\phi \to 0$. Here, we show for the first time that including the 1-loop contributions of these mediators to the standard 2-body decays (e.g., $\pi^\pm,\,K^\pm \to \ell^\pm + \nu$, etc.), the infrared divergence from the 3-body decay cancels out exactly by virtue of the Kinoshita-Lee-Nauenberg theorem. Including these cancellation effects, we then update the existing laboratory constraints on neutrinophilic scalar mediators, thereby extending the limits far beyond the decaying parent particle mass and excluding a wider range of parameter space. These new "physical" limits derived here have significant implications for the future detection prospects of nonstandard neutrino (self-)interactions.
[ { "created": "Wed, 17 Jul 2024 16:58:43 GMT", "version": "v1" } ]
2024-07-18
[ [ "Dev", "P. S. Bhupal", "" ], [ "Kim", "Doojin", "" ], [ "Sathyan", "Deepak", "" ], [ "Sinha", "Kuver", "" ], [ "Zhang", "Yongchao", "" ] ]
Neutrinophilic mediators are well-motivated messenger particles that can probe some of the least known sectors of fundamental physics involving nonstandard interactions of neutrinos with themselves and potentially with dark matter. In particular, light mediators coupling to the active neutrinos will induce new decay modes of the Standard Model mesons (e.g., $\pi^\pm, K^\pm \to \ell^\pm + \nu + \phi$), charged leptons (e.g., $\tau^\pm \to \pi^\pm + \nu + \phi$), and gauge bosons (e.g., $Z \to \nu + \bar{\nu} + \phi$). A common lore is that these decays suffer from infrared divergences in the limit of the vanishing mediator mass, i.e., $m_\phi \to 0$. Here, we show for the first time that including the 1-loop contributions of these mediators to the standard 2-body decays (e.g., $\pi^\pm,\,K^\pm \to \ell^\pm + \nu$, etc.), the infrared divergence from the 3-body decay cancels out exactly by virtue of the Kinoshita-Lee-Nauenberg theorem. Including these cancellation effects, we then update the existing laboratory constraints on neutrinophilic scalar mediators, thereby extending the limits far beyond the decaying parent particle mass and excluding a wider range of parameter space. These new "physical" limits derived here have significant implications for the future detection prospects of nonstandard neutrino (self-)interactions.
0807.4206
Fred Jegerlehner
F. Jegerlehner
The running fine structure constant alpha(E) via the Adler function
7 pages, 6 figures
Nucl.Phys.Proc.Suppl.181-182:135-140,2008
10.1016/j.nuclphysbps.2008.09.010
DESY 08-078
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an up-to-date analysis for a precise determination of the effective fine structure constant and discuss the prospects for future improvements. We advocate to use a determination monitored by the Adler function which allows us to exploit perturbative QCD in an optimal well controlled way. Together with a long term program of hadronic cross section measurements at energies up to a few GeV, a determination of alpha(M_Z) at a precision comparable to the one of the Z mass M_Z should be feasible. Presently alpha(E) at E>1 GeV is the least precisely known of the fundamental parameters of the SM. Since, in spite of substantial progress due to new BaBar exclusive data, the region 1.4 to 2.4 GeV remains the most problematic one a major step in the reduction of the uncertainties are expected from VEPP-2000 and from a possible ``high-energy'' option DAFNE-2 at Frascati. The up-to-date evaluation reads Delta alpha^{(5)}_{had}(M_Z^2) = 0.027515 +/- 0.000149 or alpha^{-1}(M_Z)=128.957 +/- 0.020.
[ { "created": "Sat, 26 Jul 2008 00:12:13 GMT", "version": "v1" } ]
2008-11-07
[ [ "Jegerlehner", "F.", "" ] ]
We present an up-to-date analysis for a precise determination of the effective fine structure constant and discuss the prospects for future improvements. We advocate to use a determination monitored by the Adler function which allows us to exploit perturbative QCD in an optimal well controlled way. Together with a long term program of hadronic cross section measurements at energies up to a few GeV, a determination of alpha(M_Z) at a precision comparable to the one of the Z mass M_Z should be feasible. Presently alpha(E) at E>1 GeV is the least precisely known of the fundamental parameters of the SM. Since, in spite of substantial progress due to new BaBar exclusive data, the region 1.4 to 2.4 GeV remains the most problematic one a major step in the reduction of the uncertainties are expected from VEPP-2000 and from a possible ``high-energy'' option DAFNE-2 at Frascati. The up-to-date evaluation reads Delta alpha^{(5)}_{had}(M_Z^2) = 0.027515 +/- 0.000149 or alpha^{-1}(M_Z)=128.957 +/- 0.020.
2112.12547
Olivier Lennon
Olivier Lennon
Non-Canonical Q-balls
16+2 pages
null
null
OUTP-21-29P
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
Theories possessing non-canonical kinetic terms are often studied for Q-ball states in an ad-hoc manner. This paper seeks to generalise their study for both thin- and thick-wall Q-balls. Specifically, we show that theories whose potential cannot house Q-balls can do so by virtue of their non-canonical kinetic terms. Furthermore, we also constrain the theories that possess an energetically stable thick-wall limit, with ramifications for their early universe phenomenology.
[ { "created": "Tue, 21 Dec 2021 19:00:02 GMT", "version": "v1" } ]
2021-12-24
[ [ "Lennon", "Olivier", "" ] ]
Theories possessing non-canonical kinetic terms are often studied for Q-ball states in an ad-hoc manner. This paper seeks to generalise their study for both thin- and thick-wall Q-balls. Specifically, we show that theories whose potential cannot house Q-balls can do so by virtue of their non-canonical kinetic terms. Furthermore, we also constrain the theories that possess an energetically stable thick-wall limit, with ramifications for their early universe phenomenology.
hep-ph/0302015
Luis G. Cabral-Rosetti
U. Solis, J. C. D'Olivo and L. G. Cabral-Rosetti
Neutrinos and Nucleosynthesis in Supernova
RevTex4 style, 3 pages including 1 figure. Presented at Mexican School of Astrophysics 2002, Guanajuato, Mexico, 31 Jul - 7 Aug 2002. Final version to appear in the Proceedings of IX Mexican Workshop on Particles and Fields Physics Beyond the Standard Model, Colima Col. Mexico, November 17-22, 2003
J.Phys.Conf.Ser. 37 (2006) 127-130
10.1088/1742-6596/37/1/021
null
hep-ph
null
The type II supernova is considered as a candidate site for the production of heavy elements. The nucleosynthesis occurs in an intense neutrino flux, we calculate the electron fraction in this environment.
[ { "created": "Mon, 3 Feb 2003 23:07:47 GMT", "version": "v1" }, { "created": "Fri, 7 Feb 2003 22:55:15 GMT", "version": "v2" }, { "created": "Sat, 12 Nov 2005 17:26:27 GMT", "version": "v3" } ]
2009-11-10
[ [ "Solis", "U.", "" ], [ "D'Olivo", "J. C.", "" ], [ "Cabral-Rosetti", "L. G.", "" ] ]
The type II supernova is considered as a candidate site for the production of heavy elements. The nucleosynthesis occurs in an intense neutrino flux, we calculate the electron fraction in this environment.
2307.14082
Ijaz Ahmed
Ijaz Ahmed, Waqas Ahmad, M.S. Amjad, Jamil Muhammad
Observability of Parameter Space for Charged Higgs Boson in its bosonic decays in Two Higgs Doublet Model Type-1
14 pages,20 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This study explores the possibility of discovering $H^{\pm}$ through its bosonic decays, i.e. $H^{\pm}\rightarrow W^\pm\phi$ (where $\phi$ = h or A), within the Type-I Two Higgs Doublet Model (2HDM). The main objective is to demonstrate the available parameter space after applying the recent experimental and theoretical exclusion limits. We suggest that for $m_{H^\pm}$ = 150 GeV is the most probable mass for the $H^\pm\rightarrow W^\pm\phi$ decay channel in $pp$ collisions at $\sqrt{s}$ = 8, 13 and 14 TeV. Therefore we propose that this channel may be used as an alternative to $H^\pm\rightarrow \tau^\pm\nu$.
[ { "created": "Wed, 26 Jul 2023 10:11:19 GMT", "version": "v1" }, { "created": "Fri, 27 Oct 2023 16:46:20 GMT", "version": "v2" } ]
2023-10-30
[ [ "Ahmed", "Ijaz", "" ], [ "Ahmad", "Waqas", "" ], [ "Amjad", "M. S.", "" ], [ "Muhammad", "Jamil", "" ] ]
This study explores the possibility of discovering $H^{\pm}$ through its bosonic decays, i.e. $H^{\pm}\rightarrow W^\pm\phi$ (where $\phi$ = h or A), within the Type-I Two Higgs Doublet Model (2HDM). The main objective is to demonstrate the available parameter space after applying the recent experimental and theoretical exclusion limits. We suggest that for $m_{H^\pm}$ = 150 GeV is the most probable mass for the $H^\pm\rightarrow W^\pm\phi$ decay channel in $pp$ collisions at $\sqrt{s}$ = 8, 13 and 14 TeV. Therefore we propose that this channel may be used as an alternative to $H^\pm\rightarrow \tau^\pm\nu$.
hep-ph/9712207
Wolf-Dieter Nowak
D. von Harrach (Univ. Mainz), W.-D. Nowak (DESY-IfH, Zeuthen), J. Soffer (CNRS Marseille)
Theory Meets Experiment for the Determination of $\Delta G/G$
7 pages, LaTeX; Summary of the Discussion Session at the Topical Workshop on 'Deep Inelastic Scattering off Polarized Targets: Theory Meets Experiment', DESY-Zeuthen, September 1-5, 1997
null
null
CPT-97/P.3564, DESY 97-232
hep-ph
null
We briefly summarize the main points made during the discussion session on the determination of $\Delta G/G$, where all Workshop participants were strongly encouraged to contribute.
[ { "created": "Sun, 30 Nov 1997 10:14:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "von Harrach", "D.", "", "Univ. Mainz" ], [ "Nowak", "W. -D.", "", "DESY-IfH, Zeuthen" ], [ "Soffer", "J.", "", "CNRS Marseille" ] ]
We briefly summarize the main points made during the discussion session on the determination of $\Delta G/G$, where all Workshop participants were strongly encouraged to contribute.
2404.06793
Yuki Watanabe
Ayuki Kamada, Takumi Kuwahara, Shigeki Matsumoto, Yu Watanabe, Yuki Watanabe
Mediator Decay through mixing with Degenerate Spectrum
27 pages, 11 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay of the mediator particle into standard model (SM) particles plays a significant role in exploring the dark sector scenario. We consider such a decay, taking the dark photon mediator as an example that mixes with the SM photon. We find that it requires a careful analysis of the decay rate in the presence of an SM vector boson (e.g., $Z$ boson, $\rho$ meson, and true muonium, etc.) nearly degenerate with the mediator particle in mass. The decay rate of the mediator particle calculated in the mass eigenstate basis {\bf does not} agree with the correct result, given by the imaginary parts of the poles for the vector boson propagators, when the mixing parameter is smaller than a specific value. In such a case, the decay rate calculated by treating the mixing as a perturbative parameter is in agreement with the correct result. We clarify specific values for the mixing parameter quantitatively using several concrete examples of the SM vector bosons degenerate with the dark photon. When the mass mixing between the vector boson and dark photon is smaller (larger) than the decay width of the vector boson, the latter (former) method to calculate the decay rate of the mediator particle gives the correct result.
[ { "created": "Wed, 10 Apr 2024 07:23:14 GMT", "version": "v1" } ]
2024-04-11
[ [ "Kamada", "Ayuki", "" ], [ "Kuwahara", "Takumi", "" ], [ "Matsumoto", "Shigeki", "" ], [ "Watanabe", "Yu", "" ], [ "Watanabe", "Yuki", "" ] ]
The decay of the mediator particle into standard model (SM) particles plays a significant role in exploring the dark sector scenario. We consider such a decay, taking the dark photon mediator as an example that mixes with the SM photon. We find that it requires a careful analysis of the decay rate in the presence of an SM vector boson (e.g., $Z$ boson, $\rho$ meson, and true muonium, etc.) nearly degenerate with the mediator particle in mass. The decay rate of the mediator particle calculated in the mass eigenstate basis {\bf does not} agree with the correct result, given by the imaginary parts of the poles for the vector boson propagators, when the mixing parameter is smaller than a specific value. In such a case, the decay rate calculated by treating the mixing as a perturbative parameter is in agreement with the correct result. We clarify specific values for the mixing parameter quantitatively using several concrete examples of the SM vector bosons degenerate with the dark photon. When the mass mixing between the vector boson and dark photon is smaller (larger) than the decay width of the vector boson, the latter (former) method to calculate the decay rate of the mediator particle gives the correct result.
hep-ph/0212094
Adam K. Leibovich
Sean Fleming and Adam K Leibovich
The Photon Spectrum in Upsilon Decays
27 pages, 11 figures
Phys.Rev. D67 (2003) 074035
10.1103/PhysRevD.67.074035
CMU-HEP-02-13 and FERMILAB-Pub-02/295-T
hep-ph
null
We present a theoretical prediction for the photon spectrum in radiative Upsilon decay. Parts of the spectrum have already been understood, but an understanding of the endpoint region has remained elusive. In this paper we provide the missing piece, and resolve a controversy in the literature. We treat the endpoint region of Upsilon -> X gamma decay within the framework of the soft-collinear effective theory (SCET). Within this approach the Upsilon structure function arises naturally, and kinematic logarithms are summed by running operators using renormalization group equations. In a previous paper we studied the color-octet contribution to the decay. Here we treat the color-singlet contribution. We combine our result with previous results to obtain the Upsilon -> X gamma spectrum. We find that resumming the color-singlet contribution in the endpoint gives a result that is in much better agreement with the data than the leading order prediction.
[ { "created": "Thu, 5 Dec 2002 23:49:45 GMT", "version": "v1" } ]
2009-11-07
[ [ "Fleming", "Sean", "" ], [ "Leibovich", "Adam K", "" ] ]
We present a theoretical prediction for the photon spectrum in radiative Upsilon decay. Parts of the spectrum have already been understood, but an understanding of the endpoint region has remained elusive. In this paper we provide the missing piece, and resolve a controversy in the literature. We treat the endpoint region of Upsilon -> X gamma decay within the framework of the soft-collinear effective theory (SCET). Within this approach the Upsilon structure function arises naturally, and kinematic logarithms are summed by running operators using renormalization group equations. In a previous paper we studied the color-octet contribution to the decay. Here we treat the color-singlet contribution. We combine our result with previous results to obtain the Upsilon -> X gamma spectrum. We find that resumming the color-singlet contribution in the endpoint gives a result that is in much better agreement with the data than the leading order prediction.
1104.2404
Simon de Visscher
Simon de Visscher, Michel Herquet
Automatic anomaly detection in high energy collider data
5 pages, 2 figures
null
null
NIKHEF-2010-012
hep-ph hep-ex physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the problem of automatic anomaly detection in high energy collider data. Our approach is based on the random generation of analytic expressions for kinematical variables, which can then be evolved following a genetic programming procedure to enhance their discriminating power. We apply this approach to three concrete scenarios to demonstrate its possible usefulness, both as a detailed check of reference Monte-Carlo simulations and as a model independent tool for the detection of New Physics signatures.
[ { "created": "Wed, 13 Apr 2011 08:06:10 GMT", "version": "v1" } ]
2011-04-14
[ [ "de Visscher", "Simon", "" ], [ "Herquet", "Michel", "" ] ]
We address the problem of automatic anomaly detection in high energy collider data. Our approach is based on the random generation of analytic expressions for kinematical variables, which can then be evolved following a genetic programming procedure to enhance their discriminating power. We apply this approach to three concrete scenarios to demonstrate its possible usefulness, both as a detailed check of reference Monte-Carlo simulations and as a model independent tool for the detection of New Physics signatures.
hep-ph/9512401
Esteban Roulet
A. Riotto and E. Roulet
Vacuum decay along supersymmetric flat directions
12 pages, uuencoded latex file + 4 ps figures
Phys.Lett.B377:60-66,1996
10.1016/0370-2693(96)00313-9
SISSA-95/163/EP, Fermilab-Pub-95/400-A
hep-ph astro-ph
null
It has been recently realized that within the Minimal Supersymmetric Standard Model, for certain patterns of superpartner masses, consistent with all the present experimental constraints, the scalar potential may develop at some scale $Q_0$ unbounded color/charge breaking directions involving the sfermion fields, and that these patterns are then excluded unless some new physics is invoked at or below the scale $Q_0$. We reanalyze this observation and point out that such patterns of superpartner masses at the weak scale are {\it not} ruled out when taking into account the probability of decay for the metastable color conserving minimum along these color breaking unbounded directions. It turns out that the color conserving minimum, although metastable, has a lifetime longer than the present age of the Universe and can survive both quantum tunneling and the effects of high temperatures in the early Universe, causing the color/charge breaking effects to be in practice not dangerous.
[ { "created": "Fri, 22 Dec 1995 08:26:57 GMT", "version": "v1" } ]
2008-11-26
[ [ "Riotto", "A.", "" ], [ "Roulet", "E.", "" ] ]
It has been recently realized that within the Minimal Supersymmetric Standard Model, for certain patterns of superpartner masses, consistent with all the present experimental constraints, the scalar potential may develop at some scale $Q_0$ unbounded color/charge breaking directions involving the sfermion fields, and that these patterns are then excluded unless some new physics is invoked at or below the scale $Q_0$. We reanalyze this observation and point out that such patterns of superpartner masses at the weak scale are {\it not} ruled out when taking into account the probability of decay for the metastable color conserving minimum along these color breaking unbounded directions. It turns out that the color conserving minimum, although metastable, has a lifetime longer than the present age of the Universe and can survive both quantum tunneling and the effects of high temperatures in the early Universe, causing the color/charge breaking effects to be in practice not dangerous.
1806.10940
Selym Villalba-Chavez Dr.
Selym Villalba-Ch\'avez, Alina Golub, Carsten M\"uller
Axion-modified photon propagator, Coulomb potential and Lamb-shift
16 pages, 10 figures
Phys. Rev. D 98, 115008 (2018)
10.1103/PhysRevD.98.115008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A consistent renormalization of a quantum theory of axion-electrodynamics requires terms beyond the minimal coupling of two photons to a neutral pseudoscalar field. This procedure is used to determine the self-energy operators of the electromagnetic and the axion fields with an accuracy of second-order in the axion-diphoton coupling. The resulting polarization tensor is utilized for establishing the axion-modified Coulomb potential of a static pointlike charge. In connection, the plausible distortion of the Lamb-shift in hydrogenlike atoms is established and the scopes for searching axionlike particles in high-precision atomic spectroscopy and in experiments of Cavendish-type are investigated. Particularly, we show that these hypothetical degrees of freedom are ruled out as plausible candidates for explaining the proton radius anomaly in muonic hydrogen. A certain loophole remains, though, which is linked to the nonrenormalizable nature of axion-electrodynamics.
[ { "created": "Thu, 28 Jun 2018 13:13:39 GMT", "version": "v1" }, { "created": "Thu, 6 Dec 2018 10:45:30 GMT", "version": "v2" } ]
2018-12-12
[ [ "Villalba-Chávez", "Selym", "" ], [ "Golub", "Alina", "" ], [ "Müller", "Carsten", "" ] ]
A consistent renormalization of a quantum theory of axion-electrodynamics requires terms beyond the minimal coupling of two photons to a neutral pseudoscalar field. This procedure is used to determine the self-energy operators of the electromagnetic and the axion fields with an accuracy of second-order in the axion-diphoton coupling. The resulting polarization tensor is utilized for establishing the axion-modified Coulomb potential of a static pointlike charge. In connection, the plausible distortion of the Lamb-shift in hydrogenlike atoms is established and the scopes for searching axionlike particles in high-precision atomic spectroscopy and in experiments of Cavendish-type are investigated. Particularly, we show that these hypothetical degrees of freedom are ruled out as plausible candidates for explaining the proton radius anomaly in muonic hydrogen. A certain loophole remains, though, which is linked to the nonrenormalizable nature of axion-electrodynamics.
1103.1463
Jean Cleymans
J. Cleymans, D. Worku
The Hagedorn temperature Revisited
13 pages, 4 figures
null
10.1142/S0217732311035584
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Hagedorn temperature, T_H is determined from the number of hadronic resonances including all mesons and baryons. This leads to a stable result T_H = 174 MeV consistent with the critical and the chemical freeze-out temperatures at zero chemical potential. We use this result to calculate the speed of sound and other thermodynamic quantities in the resonance hadron gas model for a wide range of baryon chemical potentials following the chemical freeze-out curve. We compare some of our results to those obtained previously in other papers.
[ { "created": "Tue, 8 Mar 2011 08:32:15 GMT", "version": "v1" }, { "created": "Wed, 9 Mar 2011 08:09:49 GMT", "version": "v2" }, { "created": "Thu, 10 Mar 2011 08:53:00 GMT", "version": "v3" }, { "created": "Mon, 14 Mar 2011 10:39:27 GMT", "version": "v4" } ]
2015-05-27
[ [ "Cleymans", "J.", "" ], [ "Worku", "D.", "" ] ]
The Hagedorn temperature, T_H is determined from the number of hadronic resonances including all mesons and baryons. This leads to a stable result T_H = 174 MeV consistent with the critical and the chemical freeze-out temperatures at zero chemical potential. We use this result to calculate the speed of sound and other thermodynamic quantities in the resonance hadron gas model for a wide range of baryon chemical potentials following the chemical freeze-out curve. We compare some of our results to those obtained previously in other papers.
hep-ph/0506177
Thomas A. Trainor
Thomas A Trainor and Duncan J Prindle (STAR Collaboration)
Transverse Momentum Correlations in Relativistic Nuclear Collisions
10 pages, 10 figures, proceedings, MIT workshop on fluctuations and correlations in relativistic nuclear collisions
J.Phys.Conf.Ser. 27 (2005) 134-143
10.1088/1742-6596/27/1/015
null
hep-ph
null
From the correlation structure of transverse momentum $p_t$ in relativistic nuclear collisions we observe for the first time temperature/velocity structure resulting from low-$Q^2$ partons. Our novel analysis technique does not invoke an {\em a priori} jet hypothesis. $p_t$ autocorrelations derived from the scale dependence of $<p_t>$ fluctuations reveal a complex parton dissipation process in RHIC heavy ion collisions. We also observe structure which may result from collective bulk-medium recoil in response to parton stopping.
[ { "created": "Fri, 17 Jun 2005 13:05:41 GMT", "version": "v1" } ]
2009-11-11
[ [ "Trainor", "Thomas A", "", "STAR Collaboration" ], [ "Prindle", "Duncan J", "", "STAR Collaboration" ] ]
From the correlation structure of transverse momentum $p_t$ in relativistic nuclear collisions we observe for the first time temperature/velocity structure resulting from low-$Q^2$ partons. Our novel analysis technique does not invoke an {\em a priori} jet hypothesis. $p_t$ autocorrelations derived from the scale dependence of $<p_t>$ fluctuations reveal a complex parton dissipation process in RHIC heavy ion collisions. We also observe structure which may result from collective bulk-medium recoil in response to parton stopping.
hep-ph/0209331
Joaquim Matias
Joaquim Matias (CERN and Universitat Autonoma Barcelona)
Impact of B physics on model building and vice versa: an example
20 pages, LaTeX
Nucl.Phys.Proc.Suppl.120:197-209,2003
10.1016/S0920-5632(03)01903-0
CERN-TH/2002-248, UAB-FT-531
hep-ph
null
We motivate that the start-up of the B factories has opened a new precision flavour physics era, with an important effect on model building. Using as an example a left-right model with spontaneous CP violation, we will show how the inclusion of the new experimental data on B physics observables, together with the old observables coming from kaon physics, has significantly widened our capacity to strongly constrain the parameter space up to the point to exclude models. On the contrary, using certain hypotheses, mainly concerning isospin, we discuss how theory may help us to `test' the data on charged, neutral and mixed $B \to \pi K$ decays once experimental errors will be reduced.
[ { "created": "Fri, 27 Sep 2002 13:17:27 GMT", "version": "v1" } ]
2011-03-23
[ [ "Matias", "Joaquim", "", "CERN and Universitat Autonoma Barcelona" ] ]
We motivate that the start-up of the B factories has opened a new precision flavour physics era, with an important effect on model building. Using as an example a left-right model with spontaneous CP violation, we will show how the inclusion of the new experimental data on B physics observables, together with the old observables coming from kaon physics, has significantly widened our capacity to strongly constrain the parameter space up to the point to exclude models. On the contrary, using certain hypotheses, mainly concerning isospin, we discuss how theory may help us to `test' the data on charged, neutral and mixed $B \to \pi K$ decays once experimental errors will be reduced.
hep-ph/9805224
Stefan Groote
S. Groote, J.G. K\"orner and A.A. Pivovarov
A new technique for computing the spectral density of sunset-type diagrams: integral transformation in configuration space
13 pages in LaTeX, one PostScript figure included in the text
Phys.Lett. B443 (1998) 269-275
10.1016/S0370-2693(98)01324-0
MZ-TH/98-12
hep-ph nucl-th
null
We present a new method to investigate a class of diagrams which generalizes the sunset topology to any number of massive internal lines. Our attention is focused on the computation of the spectral density of these diagrams which is related to many-body phase space in $D$ dimensional space-time. The spectral density is determined by the inverse $K$-transform of the product of propagators in configuration space. The inverse $K$-transform reduces to the inverse Laplace transform in any odd number of space-time dimensions for which we present an explicit analytical result.
[ { "created": "Tue, 5 May 1998 10:36:54 GMT", "version": "v1" }, { "created": "Thu, 29 Oct 1998 07:34:05 GMT", "version": "v2" }, { "created": "Wed, 5 Apr 2000 06:56:50 GMT", "version": "v3" } ]
2009-10-31
[ [ "Groote", "S.", "" ], [ "Körner", "J. G.", "" ], [ "Pivovarov", "A. A.", "" ] ]
We present a new method to investigate a class of diagrams which generalizes the sunset topology to any number of massive internal lines. Our attention is focused on the computation of the spectral density of these diagrams which is related to many-body phase space in $D$ dimensional space-time. The spectral density is determined by the inverse $K$-transform of the product of propagators in configuration space. The inverse $K$-transform reduces to the inverse Laplace transform in any odd number of space-time dimensions for which we present an explicit analytical result.
hep-ph/0307046
Agustin Sabio-Vera
Agustin Sabio Vera (Cambridge U.)
Solution of the BFKL Equation at Next-to-leading Order
5 pages, presented at the DIS 2003 Workshop, St. Peterburg, Russia, 23-27 April 2003
null
null
Cavendish-HEP-03/06
hep-ph
null
We solve the Balitsky-Fadin-Kuraev-Lipatov equation in the next-to-leading logarithmic approximation for forward scattering with all conformal spins using an iterative method.
[ { "created": "Thu, 3 Jul 2003 14:32:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Vera", "Agustin Sabio", "", "Cambridge U." ] ]
We solve the Balitsky-Fadin-Kuraev-Lipatov equation in the next-to-leading logarithmic approximation for forward scattering with all conformal spins using an iterative method.
1106.5071
Zhenyu Han
Yang Bai and Zhenyu Han
Improving the Top Quark Forward-Backward Asymmetry Measurement at the LHC
26 pages, 11 figures
null
10.1007/JHEP02(2012)135
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
At the LHC, top quark pairs are dominantly produced from gluons, making it difficult to measure the top quark forward-backward asymmetry. To improve the asymmetry measurement, we study variables that can distinguish between top quarks produced from quarks and those from gluons: the invariant mass of the top pair, the rapidity of the top-antitop system in the lab frame, the rapidity of the top quark in the top-antitop rest frame, the top quark polarization and the top-antitop spin correlation. We combine all the variables in a likelihood discriminant method to separate quark-initiated events from gluon-initiated events. We apply our method on models including G-prime's and W-prime's motivated by the recent observation of a large top quark forward-backward asymmetry at the Tevatron. We have found that the significance of the asymmetry measurement can be improved by 10% to 30%. At the same time, the central values of the asymmetry increase by 40% to 100%. We have also analytically derived the best spin quantization axes for studying top quark polarization as well as spin-correlation for the new physics models.
[ { "created": "Fri, 24 Jun 2011 21:50:21 GMT", "version": "v1" } ]
2015-05-28
[ [ "Bai", "Yang", "" ], [ "Han", "Zhenyu", "" ] ]
At the LHC, top quark pairs are dominantly produced from gluons, making it difficult to measure the top quark forward-backward asymmetry. To improve the asymmetry measurement, we study variables that can distinguish between top quarks produced from quarks and those from gluons: the invariant mass of the top pair, the rapidity of the top-antitop system in the lab frame, the rapidity of the top quark in the top-antitop rest frame, the top quark polarization and the top-antitop spin correlation. We combine all the variables in a likelihood discriminant method to separate quark-initiated events from gluon-initiated events. We apply our method on models including G-prime's and W-prime's motivated by the recent observation of a large top quark forward-backward asymmetry at the Tevatron. We have found that the significance of the asymmetry measurement can be improved by 10% to 30%. At the same time, the central values of the asymmetry increase by 40% to 100%. We have also analytically derived the best spin quantization axes for studying top quark polarization as well as spin-correlation for the new physics models.
hep-ph/0606208
Hua-Xing Chen
Hua-Xing Chen, Atsushi Hosaka and Shi-Lin Zhu
Isospin symmetry breaking of K and K* mesons
9 pages, 7 figures, one reference added
Phys.Rev.D74:033007,2006
10.1103/PhysRevD.74.033007
null
hep-ph hep-ex
null
We use the method of QCD sum rules to investigate the isospin symmetry breaking of K and K* mesons. The electromagnetic effect, difference between up and down current-quark masses and difference between up and down quark condensates are important. We perform sum rule analyses of their masses and decay constant differences, which are consistent with experimental values. Our results yield Delta f_K = f_{K^0} - f_{K^\pm} = 1.5 MeV.
[ { "created": "Tue, 20 Jun 2006 02:20:24 GMT", "version": "v1" }, { "created": "Fri, 21 Jul 2006 02:41:07 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chen", "Hua-Xing", "" ], [ "Hosaka", "Atsushi", "" ], [ "Zhu", "Shi-Lin", "" ] ]
We use the method of QCD sum rules to investigate the isospin symmetry breaking of K and K* mesons. The electromagnetic effect, difference between up and down current-quark masses and difference between up and down quark condensates are important. We perform sum rule analyses of their masses and decay constant differences, which are consistent with experimental values. Our results yield Delta f_K = f_{K^0} - f_{K^\pm} = 1.5 MeV.
2001.08965
Claudia Garcia-Garcia
Claudia Garcia-Garcia
New Physics Signals of the Electroweak Chiral Lagrangian in Vector Boson Scattering at the LHC
PhD Thesis. Universidad Autonoma de Madrid. Defended the 15th of October 2019. 183 pages + Appendices. 67 figures, 15 tables. Main text in English. Introduction and Conclusion also in Spanish
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model of fundamental interactions, albeit an incredibly elegant and successful theory, lacks explanations for some experimental and theoretical open questions. Interestingly, many of these problems seem to be related to the electroweak symmetry breaking sector of the theory, whose dynamical generation is still unknown. Important questions such as what is the true nature of the Higgs boson, why is its mass so light and so close to that of the electroweak gauge bosons or whether the properties of this particle are the ones predicted in the Standard Model remain unanswered. The LHC is our tool to unveil these mysteries and vector boson scattering processes are the perfect window to access them, since they are considered as the most sensitive observables to new physics in the electroweak symmetry breaking sector. In this Thesis we employ the effective electroweak chiral Lagrangian with a light Higgs, which assumes a strongly interacting electroweak symmetry breaking sector, to perform a model independent analysis of the phenomenology of vector boson scattering processes at the LHC as well as to present quantitative predictions for the sensitivity to possible beyond the Standard Model physics scenarios.
[ { "created": "Fri, 24 Jan 2020 12:40:14 GMT", "version": "v1" } ]
2020-01-27
[ [ "Garcia-Garcia", "Claudia", "" ] ]
The Standard Model of fundamental interactions, albeit an incredibly elegant and successful theory, lacks explanations for some experimental and theoretical open questions. Interestingly, many of these problems seem to be related to the electroweak symmetry breaking sector of the theory, whose dynamical generation is still unknown. Important questions such as what is the true nature of the Higgs boson, why is its mass so light and so close to that of the electroweak gauge bosons or whether the properties of this particle are the ones predicted in the Standard Model remain unanswered. The LHC is our tool to unveil these mysteries and vector boson scattering processes are the perfect window to access them, since they are considered as the most sensitive observables to new physics in the electroweak symmetry breaking sector. In this Thesis we employ the effective electroweak chiral Lagrangian with a light Higgs, which assumes a strongly interacting electroweak symmetry breaking sector, to perform a model independent analysis of the phenomenology of vector boson scattering processes at the LHC as well as to present quantitative predictions for the sensitivity to possible beyond the Standard Model physics scenarios.
2407.13815
Kevin Langhoff
Simon Knapen, Kevin Langhoff, Zoltan Ligeti
Imprints of supersymmetry at a future Z factory
13 pages, 6 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the discovery potential of Z branching ratios due to contributions induced by the MSSM electroweak sector, assuming that the squarks and gluinos are heavy. Precision measurements at a future Z factory would yield sensitivity to MSSM that is complementary to direct searches at the LHC, provided that the systematic uncertainties can be reduced to a level comparable to the expected statistical uncertainties.
[ { "created": "Thu, 18 Jul 2024 18:00:00 GMT", "version": "v1" } ]
2024-07-22
[ [ "Knapen", "Simon", "" ], [ "Langhoff", "Kevin", "" ], [ "Ligeti", "Zoltan", "" ] ]
We study the discovery potential of Z branching ratios due to contributions induced by the MSSM electroweak sector, assuming that the squarks and gluinos are heavy. Precision measurements at a future Z factory would yield sensitivity to MSSM that is complementary to direct searches at the LHC, provided that the systematic uncertainties can be reduced to a level comparable to the expected statistical uncertainties.
2305.07536
Aniello Quaranta
Antonio Capolupo, Salvatore Marco Giampaolo, Aniello Quaranta
Axion like particles, fifth force and neutron interferometry
Presented at DICE2022 conference
null
10.1088/1742-6596/2533/1/012044
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
We report on recent result according to which the fermion-fermion interaction mediated by axions and axion-like particles can be revealed by means of neutron interferometry. We assume that the initial neutron beam is split in two beams which are affected by differently oriented magnetic fields, in order that the phase difference depends only by the axion-induced interaction. In this way, the phase difference is directly related to the presence of axions.
[ { "created": "Fri, 12 May 2023 14:54:38 GMT", "version": "v1" } ]
2024-03-06
[ [ "Capolupo", "Antonio", "" ], [ "Giampaolo", "Salvatore Marco", "" ], [ "Quaranta", "Aniello", "" ] ]
We report on recent result according to which the fermion-fermion interaction mediated by axions and axion-like particles can be revealed by means of neutron interferometry. We assume that the initial neutron beam is split in two beams which are affected by differently oriented magnetic fields, in order that the phase difference depends only by the axion-induced interaction. In this way, the phase difference is directly related to the presence of axions.
2107.05352
Gernot Eichmann
Gernot Eichmann, Jan M. Pawlowski, Jo\~ao M. Silva
On mass generation in Landau-gauge Yang-Mills theory
33 pages, 24 figures. Identical to the version published in Phys. Rev. D
null
10.1103/PhysRevD.104.114016
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A longstanding question in QCD is the origin of the mass gap in the Yang-Mills sector of QCD, i.e., QCD without quarks. In Landau gauge QCD this mass gap, and hence confinement, is encoded in a mass gap of the gluon propagator, which is found both in lattice simulations and with functional approaches. While functional methods are well suited to unravel the mechanism behind the generation of the mass gap, a fully satisfactory answer has not yet been found. In this work we solve the coupled Dyson-Schwinger equations for the ghost propagator, gluon propagator and three-gluon vertex. We corroborate the findings of earlier works, namely that the mass gap generation is tied to the longitudinal projection of the gluon self-energy, which acts as an effective mass term in the equations. Because an explicit mass term is in conflict with gauge invariance, this leaves two possible scenarios: If it is viewed as an artifact, only the scaling solution survives; if it is dynamical, gauge invariance can only be preserved if there are longitudinal massless poles in either of the vertices. We find that there is indeed a massless pole in the ghost-gluon vertex, however in our approximation with the assumption of complete infrared dominance of the ghost this pole is only present for the scaling solution. We also put forward a possible mechanism that may reconcile the scaling solution, with an infrared dominance of the ghost, with the decoupling solutions based on longitudinal poles in the three-gluon vertex as seen in the PT-BFM scheme.
[ { "created": "Mon, 12 Jul 2021 12:19:09 GMT", "version": "v1" }, { "created": "Wed, 15 Dec 2021 12:11:10 GMT", "version": "v2" } ]
2021-12-22
[ [ "Eichmann", "Gernot", "" ], [ "Pawlowski", "Jan M.", "" ], [ "Silva", "João M.", "" ] ]
A longstanding question in QCD is the origin of the mass gap in the Yang-Mills sector of QCD, i.e., QCD without quarks. In Landau gauge QCD this mass gap, and hence confinement, is encoded in a mass gap of the gluon propagator, which is found both in lattice simulations and with functional approaches. While functional methods are well suited to unravel the mechanism behind the generation of the mass gap, a fully satisfactory answer has not yet been found. In this work we solve the coupled Dyson-Schwinger equations for the ghost propagator, gluon propagator and three-gluon vertex. We corroborate the findings of earlier works, namely that the mass gap generation is tied to the longitudinal projection of the gluon self-energy, which acts as an effective mass term in the equations. Because an explicit mass term is in conflict with gauge invariance, this leaves two possible scenarios: If it is viewed as an artifact, only the scaling solution survives; if it is dynamical, gauge invariance can only be preserved if there are longitudinal massless poles in either of the vertices. We find that there is indeed a massless pole in the ghost-gluon vertex, however in our approximation with the assumption of complete infrared dominance of the ghost this pole is only present for the scaling solution. We also put forward a possible mechanism that may reconcile the scaling solution, with an infrared dominance of the ghost, with the decoupling solutions based on longitudinal poles in the three-gluon vertex as seen in the PT-BFM scheme.
0706.2972
Mauro Napsuciale
M. Napsuciale, E. Oset, K. Sasaki, C. A. Vaquera-Araujo
Electron-positron annihilation into phi f_{0}(980) and clues for a new 1^{--} resonance
18 pages, 4 figures
Phys.Rev.D76:074012,2007
10.1103/PhysRevD.76.074012
null
hep-ph
null
We study the e^{+}e^{-} to phi pi pi reaction for pions in an isoscalar s-wave which is dominated by loop mechanisms. For kaon loops we start from the conventional RCHPT, but use the unitarized amplitude for KbarK-pipi scattering and the full kaon form factor instead of the lowest order terms. We study also effects of vector mesons using RCHPT supplemented with the conventional anomalous term for VVP interactions and taking into account the effects of heavy vector mesons in the K*K transition form factor. We find a peak in the dipion invariant mass around the f_{0}(980) as in the experiment. Selecting the phi f_{0}(980) contribution as a function of the e^{+}e^{-} energy we also reproduce the experimental data except for a narrow peak, yielding support to the existence of a 1^{--} resonance above the phi f_{0}(980) threshold, coupling strongly to this state.
[ { "created": "Wed, 20 Jun 2007 11:59:14 GMT", "version": "v1" }, { "created": "Wed, 17 Oct 2007 17:01:43 GMT", "version": "v2" } ]
2008-11-26
[ [ "Napsuciale", "M.", "" ], [ "Oset", "E.", "" ], [ "Sasaki", "K.", "" ], [ "Vaquera-Araujo", "C. A.", "" ] ]
We study the e^{+}e^{-} to phi pi pi reaction for pions in an isoscalar s-wave which is dominated by loop mechanisms. For kaon loops we start from the conventional RCHPT, but use the unitarized amplitude for KbarK-pipi scattering and the full kaon form factor instead of the lowest order terms. We study also effects of vector mesons using RCHPT supplemented with the conventional anomalous term for VVP interactions and taking into account the effects of heavy vector mesons in the K*K transition form factor. We find a peak in the dipion invariant mass around the f_{0}(980) as in the experiment. Selecting the phi f_{0}(980) contribution as a function of the e^{+}e^{-} energy we also reproduce the experimental data except for a narrow peak, yielding support to the existence of a 1^{--} resonance above the phi f_{0}(980) threshold, coupling strongly to this state.
1308.1711
Edcel John Salumbides
E. J. Salumbides, W. Ubachs, and V. I. Korobov
Bounds on fifth forces at the sub-Angstrom length scale
null
null
10.1016/j.jms.2014.04.003
null
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Constraints on a possible fifth-force interaction between hadrons are derived based on an analysis of results from laser precision frequency measurements of antiprotonic helium atoms, both $\bar{p}\,^{4}$He$^{+}$ and $\bar{p}\,^{3}$He$^{+}$ species, and from experiments on resonant formation rates of $dd\mu^{+}$-ions in muon-catalyzed fusion processes. A comparison is made between accurate experimental data and first-principles theoretical descriptions of the exotic systems within a quantum electrodynamical framework. The agreement between theory and experiment sets limits on a possible additional hadron-hadron interaction written in the form of a Yukawa potential $V_5(r)=\alpha_5 \exp(-r/\lambda)/r$, with $\lambda$ representing the characteristic length scale associated with the mass of a hypothetical force-carrying particle via $\lambda=\hbar/(m_5c)$. The laser spectroscopic data of antiprotonic helium set a constraint of $\alpha_5/\alpha_{EM} < 10^{-8}$ for $\lambda < 1$ \AA, while the binding energy of the muonic molecular deuterium ion delivers a constraint of $\alpha_5/\alpha_{EM} \sim 10^{-5}$ for $\lambda < 0.05$ \AA, where $\alpha_{EM}$ represents the strength of the electromagnetic interaction or the fine structure constant.
[ { "created": "Wed, 7 Aug 2013 22:51:14 GMT", "version": "v1" }, { "created": "Wed, 28 Aug 2013 12:48:35 GMT", "version": "v2" } ]
2015-06-16
[ [ "Salumbides", "E. J.", "" ], [ "Ubachs", "W.", "" ], [ "Korobov", "V. I.", "" ] ]
Constraints on a possible fifth-force interaction between hadrons are derived based on an analysis of results from laser precision frequency measurements of antiprotonic helium atoms, both $\bar{p}\,^{4}$He$^{+}$ and $\bar{p}\,^{3}$He$^{+}$ species, and from experiments on resonant formation rates of $dd\mu^{+}$-ions in muon-catalyzed fusion processes. A comparison is made between accurate experimental data and first-principles theoretical descriptions of the exotic systems within a quantum electrodynamical framework. The agreement between theory and experiment sets limits on a possible additional hadron-hadron interaction written in the form of a Yukawa potential $V_5(r)=\alpha_5 \exp(-r/\lambda)/r$, with $\lambda$ representing the characteristic length scale associated with the mass of a hypothetical force-carrying particle via $\lambda=\hbar/(m_5c)$. The laser spectroscopic data of antiprotonic helium set a constraint of $\alpha_5/\alpha_{EM} < 10^{-8}$ for $\lambda < 1$ \AA, while the binding energy of the muonic molecular deuterium ion delivers a constraint of $\alpha_5/\alpha_{EM} \sim 10^{-5}$ for $\lambda < 0.05$ \AA, where $\alpha_{EM}$ represents the strength of the electromagnetic interaction or the fine structure constant.
1012.2390
Zralek Marek
Marek Zralek
50 Years of Neutrino Physics
23 pages, Lecture presented at the L Cracow School of Theoretical Physics "Particle Physics at the Dawn of the LHC", Zakopane, Poland, June 9-19, 2010
Acta Physica Polonica B vol. 41 (2011) page 2563
null
null
hep-ph hep-ex physics.hist-ph
http://creativecommons.org/licenses/by-nc-sa/3.0/
Some important topics from history of neutrino physics over the last fifty years are discussed. History of neutrinos is older, at 4th December 2010 it will be eightieth anniversary of the "neutrino birth". In that day W. Pauli wrote the famous letter to participants of the physics conference at Tubingen with the suggestion that "there could exist in the nuclei electrically neutral particle". We will concentrate mostly on the 50 years of neutrino history just to show the long tradition of the Zakopane Theoretical School.
[ { "created": "Fri, 10 Dec 2010 21:15:26 GMT", "version": "v1" } ]
2011-01-18
[ [ "Zralek", "Marek", "" ] ]
Some important topics from history of neutrino physics over the last fifty years are discussed. History of neutrinos is older, at 4th December 2010 it will be eightieth anniversary of the "neutrino birth". In that day W. Pauli wrote the famous letter to participants of the physics conference at Tubingen with the suggestion that "there could exist in the nuclei electrically neutral particle". We will concentrate mostly on the 50 years of neutrino history just to show the long tradition of the Zakopane Theoretical School.
hep-ph/9905390
Markus A. Luty
Z. Chacko, Markus A. Luty, Ivan Maksymyk, Eduardo Ponton
Realistic Anomaly-mediated Supersymmetry Breaking
32 pages, LaTeX2e, 3 eps figures
JHEP 0004 (2000) 001
10.1088/1126-6708/2000/04/001
UMD-PP-99-102
hep-ph
null
We consider supersymmetry breaking communicated entirely by the superconformal anomaly in supergravity. This scenario is naturally realized if supersymmetry is broken in a hidden sector whose couplings to the observable sector are suppressed by more than powers of the Planck scale, as occurs if supersymmetry is broken in a parallel universe living in extra dimensions. This scenario is extremely predictive: soft supersymmetry breaking couplings are completely determined by anomalous dimensions in the effective theory at the weak scale. Gaugino and scalar masses are naturally of the same order, and flavor-changing neutral currents are automatically suppressed. The most glaring problem with this scenario is that slepton masses are negative in the minimal supersymmetric standard model. We point out that this problem can be simply solved by coupling extra Higgs doublets to the leptons. Lepton flavor-changing neutral currents can be naturally avoided by approximate symmetries. We also describe more speculative solutions involving compositeness near the weak scale. We then turn to electroweak symmetry breaking. Adding an explicit \mu term gives a value for B\mu that is too large by a factor of order 100. We construct a realistic model in which the \mu term arises from the vacuum expectation value of a singlet field, so all weak-scale masses are directly related to m_{3/2}. We show that fully realistic electroweak symmetry breaking can occur in this model with moderate fine-tuning.
[ { "created": "Tue, 18 May 1999 21:10:17 GMT", "version": "v1" } ]
2009-10-31
[ [ "Chacko", "Z.", "" ], [ "Luty", "Markus A.", "" ], [ "Maksymyk", "Ivan", "" ], [ "Ponton", "Eduardo", "" ] ]
We consider supersymmetry breaking communicated entirely by the superconformal anomaly in supergravity. This scenario is naturally realized if supersymmetry is broken in a hidden sector whose couplings to the observable sector are suppressed by more than powers of the Planck scale, as occurs if supersymmetry is broken in a parallel universe living in extra dimensions. This scenario is extremely predictive: soft supersymmetry breaking couplings are completely determined by anomalous dimensions in the effective theory at the weak scale. Gaugino and scalar masses are naturally of the same order, and flavor-changing neutral currents are automatically suppressed. The most glaring problem with this scenario is that slepton masses are negative in the minimal supersymmetric standard model. We point out that this problem can be simply solved by coupling extra Higgs doublets to the leptons. Lepton flavor-changing neutral currents can be naturally avoided by approximate symmetries. We also describe more speculative solutions involving compositeness near the weak scale. We then turn to electroweak symmetry breaking. Adding an explicit \mu term gives a value for B\mu that is too large by a factor of order 100. We construct a realistic model in which the \mu term arises from the vacuum expectation value of a singlet field, so all weak-scale masses are directly related to m_{3/2}. We show that fully realistic electroweak symmetry breaking can occur in this model with moderate fine-tuning.
hep-ph/9607451
Apostolos Pilaftsis
Apostolos Pilaftsis
Generalized Pinch Technique and the Background Field Method in General Gauges
29 pages, a reference and clarifying comments added. Version to appear in Nucl. Phys. B
Nucl.Phys. B487 (1997) 467-491
10.1016/S0550-3213(96)00686-4
RAL-TR-96-055
hep-ph hep-th
null
It is shown that Cornwall's pinch technique can be extended in a consistent diagrammatic way, so as to describe general background field gauges in Yang-Mills theories. The resulting one-loop Green's functions are found to obey Ward identities identical to those derived from the classical action at the tree level. This generalization of the pinch technique may hence be related to the background field method implemented with novel gauge-fixing conditions invariant under background field gauge transformations. To one loop, the connection between the generalized pinch technique and the background field method in covariant and in non-covariant gauges is explicitly demonstrated.
[ { "created": "Sat, 27 Jul 1996 20:56:55 GMT", "version": "v1" }, { "created": "Tue, 17 Dec 1996 18:25:28 GMT", "version": "v2" } ]
2009-10-28
[ [ "Pilaftsis", "Apostolos", "" ] ]
It is shown that Cornwall's pinch technique can be extended in a consistent diagrammatic way, so as to describe general background field gauges in Yang-Mills theories. The resulting one-loop Green's functions are found to obey Ward identities identical to those derived from the classical action at the tree level. This generalization of the pinch technique may hence be related to the background field method implemented with novel gauge-fixing conditions invariant under background field gauge transformations. To one loop, the connection between the generalized pinch technique and the background field method in covariant and in non-covariant gauges is explicitly demonstrated.
2106.14791
Gabriella Piccinelli
Gabriella Piccinelli and Angel S\'anchez
Toward a magnetic warm inflation scenario
15 pages, 5 figures. This version is very close to the published one, where several improvements were made. Some sections were reorganized and one was added; 3 figures were added. The abstract, introduction and conclusions were consequently slightly modified
Phys. Rev. D 106, 043511 (2022)
10.1103/PhysRevD.106.043511
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this work we explore the effects that a possible primordial magnetic field can have on the inflaton effective potential, taking as the underlying model a warm inflation scenario, based on global supersymmetry with a new-inflation-type potential. The decay scheme for the inflaton field is a two-step process of radiation production, where the inflaton couples to heavy intermediate superfields, which in turn interact with light particles. In this context, we consider that both sectors, heavy and light, are charged and work in the strong magnetic field approximation for the light fields. We find an analytical expression for the one-loop effective potential, for an arbitrary magnetic field strength, and show that the trend of the magnetic contribution is to make the potential flatter in the origin's vicinity, preserving the conditions for a successful inflationary process. This result is backed up by the behavior of slow-roll parameter $\epsilon$. The viability of this magnetic warm inflation scenario is also supported by the estimation of the effect of the magnetic field on the heavy particles decay width.
[ { "created": "Mon, 28 Jun 2021 15:13:42 GMT", "version": "v1" }, { "created": "Tue, 9 Aug 2022 19:09:57 GMT", "version": "v2" } ]
2022-08-11
[ [ "Piccinelli", "Gabriella", "" ], [ "Sánchez", "Angel", "" ] ]
In this work we explore the effects that a possible primordial magnetic field can have on the inflaton effective potential, taking as the underlying model a warm inflation scenario, based on global supersymmetry with a new-inflation-type potential. The decay scheme for the inflaton field is a two-step process of radiation production, where the inflaton couples to heavy intermediate superfields, which in turn interact with light particles. In this context, we consider that both sectors, heavy and light, are charged and work in the strong magnetic field approximation for the light fields. We find an analytical expression for the one-loop effective potential, for an arbitrary magnetic field strength, and show that the trend of the magnetic contribution is to make the potential flatter in the origin's vicinity, preserving the conditions for a successful inflationary process. This result is backed up by the behavior of slow-roll parameter $\epsilon$. The viability of this magnetic warm inflation scenario is also supported by the estimation of the effect of the magnetic field on the heavy particles decay width.
2205.02576
Yu. A. Simonov
A.M.Badalian and Yu.A.Simonov
The two-channel exotic charmonium-like resonances in the mass region $(3900-4700)$ MeV
19 pages
null
10.1140/epjc/s10052-022-11006-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The resonances, containing $c\bar c$ plus $s\bar s$ (or light $q\bar q$) quarks in the mass region $(3900-4700)$ MeV, are analyzed in the relativistic strong coupling theory, with and without channel coupling phenomena. The conventional charmonium spectrum is presented, being calculated with the relativistic string Hamiltonian, which does not contain fitting parameters, while for high excitations the universal flattened confining potential is used. It is shown that $X(4274),X(4500),X(4700)$ can be identified as $3\,^3P_1, 4\,^3P_0, 5\,^3P_0$ states. The exotic states are considered using the coupled-channel (recoupling) theory, when two mesons $m_1,m_2$ transfer into another two mesons $m_3, m_4$ and back (infinite number of times), creating the four-quark systems. The resonances $X(3875), X(3915), Z_{cs}(3985), X(4140)$ can be explained in this way as the exotic four-quark states in the $S$-wave decay channels.
[ { "created": "Thu, 5 May 2022 11:18:19 GMT", "version": "v1" }, { "created": "Mon, 9 May 2022 09:23:08 GMT", "version": "v2" }, { "created": "Tue, 12 Jul 2022 08:58:11 GMT", "version": "v3" }, { "created": "Mon, 10 Oct 2022 16:32:36 GMT", "version": "v4" }, { "created": "Tue, 11 Oct 2022 20:09:22 GMT", "version": "v5" }, { "created": "Tue, 1 Nov 2022 09:01:51 GMT", "version": "v6" } ]
2022-11-30
[ [ "Badalian", "A. M.", "" ], [ "Simonov", "Yu. A.", "" ] ]
The resonances, containing $c\bar c$ plus $s\bar s$ (or light $q\bar q$) quarks in the mass region $(3900-4700)$ MeV, are analyzed in the relativistic strong coupling theory, with and without channel coupling phenomena. The conventional charmonium spectrum is presented, being calculated with the relativistic string Hamiltonian, which does not contain fitting parameters, while for high excitations the universal flattened confining potential is used. It is shown that $X(4274),X(4500),X(4700)$ can be identified as $3\,^3P_1, 4\,^3P_0, 5\,^3P_0$ states. The exotic states are considered using the coupled-channel (recoupling) theory, when two mesons $m_1,m_2$ transfer into another two mesons $m_3, m_4$ and back (infinite number of times), creating the four-quark systems. The resonances $X(3875), X(3915), Z_{cs}(3985), X(4140)$ can be explained in this way as the exotic four-quark states in the $S$-wave decay channels.
1302.6995
Christopher W. Murphy
Benjam\'in Grinstein, Christopher W. Murphy
Bottom-Quark Forward-Backward Asymmetry in the Standard Model and Beyond
v3: Bug found in FeynRules 1.6.1 (not present in current version, 2.0.24) One plot corrected. Conclusions unaffected
null
10.1103/PhysRevLett.111.062003
UCSD/PTH 13-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We computed the bottom-quark forward-backward asymmetry at the Tevatron in the Standard Model and for several new physics scenarios. Near the $Z$-pole, the SM bottom asymmetry is dominated by tree level exchanges of electroweak gauge bosons. While above the $Z$-pole, next-to-leading order QCD dominates the SM asymmetry as was the case with the top quark forward-backward asymmetry. Light new physics, $M_{NP} \precsim 150$ GeV, can cause significant deviations from the SM prediction for the bottom asymmetry. The bottom asymmetry can be used to distinguish between competing NP explanations of the top asymmetry based on how the NP interferes with s-channel gluon and $Z$ exchange.
[ { "created": "Wed, 27 Feb 2013 21:00:02 GMT", "version": "v1" }, { "created": "Thu, 1 Aug 2013 01:14:06 GMT", "version": "v2" }, { "created": "Thu, 10 Jul 2014 20:22:08 GMT", "version": "v3" } ]
2014-07-14
[ [ "Grinstein", "Benjamín", "" ], [ "Murphy", "Christopher W.", "" ] ]
We computed the bottom-quark forward-backward asymmetry at the Tevatron in the Standard Model and for several new physics scenarios. Near the $Z$-pole, the SM bottom asymmetry is dominated by tree level exchanges of electroweak gauge bosons. While above the $Z$-pole, next-to-leading order QCD dominates the SM asymmetry as was the case with the top quark forward-backward asymmetry. Light new physics, $M_{NP} \precsim 150$ GeV, can cause significant deviations from the SM prediction for the bottom asymmetry. The bottom asymmetry can be used to distinguish between competing NP explanations of the top asymmetry based on how the NP interferes with s-channel gluon and $Z$ exchange.
0709.4408
Georg Weiglein
Georg Weiglein
SUSY Higgs bosons at the LHC
4 pages, contribution to the proceedings of the 42nd Rencontres de Moriond, QCD session, La Thuile, March 17-24, 2007
null
null
IPPP/07/57, DCPT/07/114
hep-ph
null
Recent results on MSSM Higgs physics at the LHC are reviewed. The dependence of the LHC discovery reach in the b\bar b H/A, H/A \to \tau^+\tau^- channel on the underlying SUSY scenario is analysed. This is done by combining the latest results for the prospective CMS experimental sensitivities for an integrated luminosity of 30 or 60 fb^-1 with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The results are interpreted in terms of the parameters governing the MSSM Higgs sector at lowest order, M_A and tan_beta. While the higgsino mass parameter \mu has a significant impact on the prospective discovery reach (and correspondingly the ``LHC wedge'' region), it is found that the discovery reach is rather stable with respect to variations of other supersymmetric parameters. Within the discovery region a determination of the masses of the heavy neutral Higgs bosons with an accuracy of 1-4% seems feasible. It is furthermore shown that Higgs-boson production in central exclusive diffractive channels can provide important information on the properties of the neutral MSSM Higgs bosons.
[ { "created": "Thu, 27 Sep 2007 14:34:55 GMT", "version": "v1" } ]
2007-09-28
[ [ "Weiglein", "Georg", "" ] ]
Recent results on MSSM Higgs physics at the LHC are reviewed. The dependence of the LHC discovery reach in the b\bar b H/A, H/A \to \tau^+\tau^- channel on the underlying SUSY scenario is analysed. This is done by combining the latest results for the prospective CMS experimental sensitivities for an integrated luminosity of 30 or 60 fb^-1 with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The results are interpreted in terms of the parameters governing the MSSM Higgs sector at lowest order, M_A and tan_beta. While the higgsino mass parameter \mu has a significant impact on the prospective discovery reach (and correspondingly the ``LHC wedge'' region), it is found that the discovery reach is rather stable with respect to variations of other supersymmetric parameters. Within the discovery region a determination of the masses of the heavy neutral Higgs bosons with an accuracy of 1-4% seems feasible. It is furthermore shown that Higgs-boson production in central exclusive diffractive channels can provide important information on the properties of the neutral MSSM Higgs bosons.
hep-ph/9610338
Iain Stewart
Iain W. Stewart (1 and 2), and Peter G. Blunden (1 and 3) ((1) Univ. of Manitoba, (2) Cal Tech, (3) Univ. of Washington)
Quantum solitons at strong coupling
17 pages, 4 Postscript figures, REVTeX
Phys.Rev.D55:3742-3747,1997
10.1103/PhysRevD.55.3742
CALT-68-2080
hep-ph hep-th
null
We examine the effect of one loop quantum corrections on the formation of nontopological solitons in a strongly coupled scalar-fermionic Yukawa theory. The exact one fermion loop contribution is incorporated by using a nonlocal method to correct the local derivative expansion approximation (DE) of the effective action. As the Yukawa coupling is increased we find that the nonlocal corrections play an increasingly important role. The corrections cause the scalar field to increase in depth while maintaining its size. This increases the energy of the bag configuration, but this is compensated for by more tightly bound fermionic states with lower energy. In contrast to the semi-classical picture without quantum corrections, the binding energy is small, and the total energy scales directly with the Yukawa coupling. This confirms the qualitative behavior found in earlier work using the second order DE, although the quantitative solutions differ.
[ { "created": "Sat, 12 Oct 1996 01:36:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Stewart", "Iain W.", "", "1 and 2" ], [ "Blunden", "Peter G.", "", "1 and 3" ] ]
We examine the effect of one loop quantum corrections on the formation of nontopological solitons in a strongly coupled scalar-fermionic Yukawa theory. The exact one fermion loop contribution is incorporated by using a nonlocal method to correct the local derivative expansion approximation (DE) of the effective action. As the Yukawa coupling is increased we find that the nonlocal corrections play an increasingly important role. The corrections cause the scalar field to increase in depth while maintaining its size. This increases the energy of the bag configuration, but this is compensated for by more tightly bound fermionic states with lower energy. In contrast to the semi-classical picture without quantum corrections, the binding energy is small, and the total energy scales directly with the Yukawa coupling. This confirms the qualitative behavior found in earlier work using the second order DE, although the quantitative solutions differ.
hep-ph/9304233
Silas Beane
Silas R. Beane and Samir Varma
Strongly Interacting W's and Z's and the Existence of a Heavy Fourth Generation of Fermions
8 pages including 4 uuencoded, tarred, and compressed postscript figures, CPP-93-09
Phys.Lett. B313 (1993) 165-170
10.1016/0370-2693(93)91207-4
null
hep-ph
null
By employing the dictum that axiomatic principles are devoid of predictive power, we find that the elastic unitarity constraint, applied to strong W$_L$W$_L$ scattering, does not alter the assumed spectrum of intermediate states. We consider intermediate states involving a heavy Higgs and heavy fermions of a hypothetical fourth generation doublet. In contrast to recent studies, we find no p-wave resonance, and therefore no violation of the S parameter upper bound. We conclude that the elastic unitarity constraint sheds no light on the existence of a heavy fourth generation.
[ { "created": "Thu, 8 Apr 1993 14:14:24 GMT", "version": "v1" } ]
2009-10-22
[ [ "Beane", "Silas R.", "" ], [ "Varma", "Samir", "" ] ]
By employing the dictum that axiomatic principles are devoid of predictive power, we find that the elastic unitarity constraint, applied to strong W$_L$W$_L$ scattering, does not alter the assumed spectrum of intermediate states. We consider intermediate states involving a heavy Higgs and heavy fermions of a hypothetical fourth generation doublet. In contrast to recent studies, we find no p-wave resonance, and therefore no violation of the S parameter upper bound. We conclude that the elastic unitarity constraint sheds no light on the existence of a heavy fourth generation.
0905.2506
Christian Kellermann
Christian Kellermann, Christian S. Fischer
The four-gluon vertex and the running coupling in Landau gauge Yang-Mills theory
6 pages, 1 figure. Talk given at ExcitedQCD 2009, Feb. 8-14, Zakopane, Poland
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We summarise results for the running coupling from the four-gluon vertex in Landau gauge, SU($N_c$) Yang-Mills theory as given by a combination of dressing functions of the vertex and the gluon propagator. These functions have been determined numerically from the corresponding set of Dyson-Schwinger equations. In the infrared we obtain a nontrivial infrared fixed point which is three orders of magnitude smaller than the corresponding one in the coupling of the ghost-gluon vertex.
[ { "created": "Fri, 15 May 2009 10:01:42 GMT", "version": "v1" } ]
2009-05-18
[ [ "Kellermann", "Christian", "" ], [ "Fischer", "Christian S.", "" ] ]
We summarise results for the running coupling from the four-gluon vertex in Landau gauge, SU($N_c$) Yang-Mills theory as given by a combination of dressing functions of the vertex and the gluon propagator. These functions have been determined numerically from the corresponding set of Dyson-Schwinger equations. In the infrared we obtain a nontrivial infrared fixed point which is three orders of magnitude smaller than the corresponding one in the coupling of the ghost-gluon vertex.
1201.3696
Nobuhiro Maekawa
Yasuhiro Kurata and Nobuhiro Maekawa
Averaged Number of the Lightest Supersymmetric Particles in Decay of Superheavy Particle with Long Lifetime
9 pages
Prog. Theor. Phys. 127 (2012), 657-664
10.1143/PTP.127.657
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the averaged number \nu of the lightest supersymmetric particles (LSPs) in a shower from the decay of superheavy particle X by generalized DGLAP equations. If the primary decayed particles have color charges and the virtuality is around 10^13-10^14 GeV, the averaged number of the LSPs can become O(100). As the result, the upper limit of the mass of the superheavy particle, whose decay can produce the observed abundance of the dark matter, can increase from 10^12 GeV to 10^14 GeV. Since the typical scale of the inflaton mass of the chaotic inflation is around 10^13 GeV, the decay of the inflaton can produce the observed dark matter abundance if the reheating temperature is of order 1 GeV. Even for the standard model particles with virtuality Q\sim 10-100 TeV, the averaged number of the LSPs becomes O(0.1) for gluon, and O(0.01) for Higgs, which strongly constrains the scenario of non-thermal LSP production from the decay of moduli with 10-100 TeV mass.
[ { "created": "Wed, 18 Jan 2012 05:53:28 GMT", "version": "v1" }, { "created": "Thu, 19 Jan 2012 06:02:52 GMT", "version": "v2" } ]
2012-05-03
[ [ "Kurata", "Yasuhiro", "" ], [ "Maekawa", "Nobuhiro", "" ] ]
We calculate the averaged number \nu of the lightest supersymmetric particles (LSPs) in a shower from the decay of superheavy particle X by generalized DGLAP equations. If the primary decayed particles have color charges and the virtuality is around 10^13-10^14 GeV, the averaged number of the LSPs can become O(100). As the result, the upper limit of the mass of the superheavy particle, whose decay can produce the observed abundance of the dark matter, can increase from 10^12 GeV to 10^14 GeV. Since the typical scale of the inflaton mass of the chaotic inflation is around 10^13 GeV, the decay of the inflaton can produce the observed dark matter abundance if the reheating temperature is of order 1 GeV. Even for the standard model particles with virtuality Q\sim 10-100 TeV, the averaged number of the LSPs becomes O(0.1) for gluon, and O(0.01) for Higgs, which strongly constrains the scenario of non-thermal LSP production from the decay of moduli with 10-100 TeV mass.
hep-ph/9712415
Aharon Levy
Halina Abramowicz and Aharon Levy
The ALLM parameterization of sigma_{tot}(gamma* p) - an update
A misprint in the parameter table (table 2) was corrected
null
null
DESY 97-251
hep-ph hep-ex
null
The ALLM parameterization of sigma_{tot}(gamma* p) has been updated by using all published F_2 data to determine its parameters. The fit yields a chi^2/ndf of 0.97 for the 1356 data points. The updated ALLM parameterization, ALLM97, gives a good description of all the available data in the whole x and Q^2 range studied so far (3\times10^{-6} < x < 0.85, 0 \le Q^2 < 5000 GeV^2).
[ { "created": "Wed, 17 Dec 1997 12:55:20 GMT", "version": "v1" }, { "created": "Thu, 19 Aug 2004 17:27:52 GMT", "version": "v2" } ]
2007-05-23
[ [ "Abramowicz", "Halina", "" ], [ "Levy", "Aharon", "" ] ]
The ALLM parameterization of sigma_{tot}(gamma* p) has been updated by using all published F_2 data to determine its parameters. The fit yields a chi^2/ndf of 0.97 for the 1356 data points. The updated ALLM parameterization, ALLM97, gives a good description of all the available data in the whole x and Q^2 range studied so far (3\times10^{-6} < x < 0.85, 0 \le Q^2 < 5000 GeV^2).
0905.4594
Axel Maas
Reinhard Alkofer, Axel Maas, Daniel Zwanziger
Truncating first-order Dyson-Schwinger equations in Coulomb-Gauge Yang-Mills theory
22 pages, 4 figures, 1 table
Few Body Syst.47:73-90,2010
10.1007/s00601-009-0073-0
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The non-perturbative domain of QCD contains confinement, chiral symmetry breaking, and the bound state spectrum. For the calculation of the latter, the Coulomb gauge is particularly well-suited. Access to these non-perturbative properties should be possible by means of the Green's functions. However, Coulomb gauge is also very involved, and thus hard to tackle. We introduce a novel BRST-type operator r, and show that the left-hand side of Gauss' law is r-exact. We investigate a possible truncation scheme of the Dyson-Schwinger equations in first-order formalism for the propagators based on an instantaneous approximation. We demonstrate that this is insufficient to obtain solutions with the expected property of a linear-rising Coulomb potential. We also show systematically that a class of possible vertex dressings does not change this result.
[ { "created": "Thu, 28 May 2009 09:53:54 GMT", "version": "v1" } ]
2010-01-15
[ [ "Alkofer", "Reinhard", "" ], [ "Maas", "Axel", "" ], [ "Zwanziger", "Daniel", "" ] ]
The non-perturbative domain of QCD contains confinement, chiral symmetry breaking, and the bound state spectrum. For the calculation of the latter, the Coulomb gauge is particularly well-suited. Access to these non-perturbative properties should be possible by means of the Green's functions. However, Coulomb gauge is also very involved, and thus hard to tackle. We introduce a novel BRST-type operator r, and show that the left-hand side of Gauss' law is r-exact. We investigate a possible truncation scheme of the Dyson-Schwinger equations in first-order formalism for the propagators based on an instantaneous approximation. We demonstrate that this is insufficient to obtain solutions with the expected property of a linear-rising Coulomb potential. We also show systematically that a class of possible vertex dressings does not change this result.
hep-ph/9706346
Masaharu Tanabashi
Iwana Inukai, Masaharu Tanabashi and Koichi Yamawaki
Top Quark Condensate in Grand Unified Theories
10pages, to appear in Proc. of 1996 International Workshop on Perspectives of Strong Coupling Gauge Theories (SCGT 96), Nagoya, Japan
null
null
TU/97/521
hep-ph
null
We propose a top quark condensate scenario embedded in grand unified theories (GUTs), stressing that the gauged Nambu-Jona-Lasinio model has a nontrivial continuum limit (``renormalizability'') under certain condition which is actually satisfied in all sensible GUTs with simple group. The top quark mass prediction in this scenario is shown to be insensitive to the ultraviolet cutoff $\Lambda$ thanks to the ``renormalizability''. We also discuss a possibility to reduce the top mass prediction in this scenario.
[ { "created": "Fri, 13 Jun 1997 01:04:40 GMT", "version": "v1" }, { "created": "Sat, 14 Jun 1997 11:06:35 GMT", "version": "v2" } ]
2008-02-03
[ [ "Inukai", "Iwana", "" ], [ "Tanabashi", "Masaharu", "" ], [ "Yamawaki", "Koichi", "" ] ]
We propose a top quark condensate scenario embedded in grand unified theories (GUTs), stressing that the gauged Nambu-Jona-Lasinio model has a nontrivial continuum limit (``renormalizability'') under certain condition which is actually satisfied in all sensible GUTs with simple group. The top quark mass prediction in this scenario is shown to be insensitive to the ultraviolet cutoff $\Lambda$ thanks to the ``renormalizability''. We also discuss a possibility to reduce the top mass prediction in this scenario.
1411.0386
Roman Nevzorov
R. Nevzorov, S. Pakvasa
Nonstandard Higgs decays in the E6 inspired SUSY models
Parallel talk at ICHEP 2014, Valencia, Spain, July 2014, 6 pages, based on arXiv:1308.1021
null
null
ADP-14-32-T891
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the exotic decays of the SM-like Higgs state within the E6 inspired supersymmetric (SUSY) models. In these models the lightest SUSY particle (LSP) can be substantially lighter than 1 eV forming hot dark matter in the Universe. The next--to--lightest SUSY particle (NLSP) also tend to be light. We argue that the NLSP with GeV scale mass may lead to the substantial branching ratio of the nonstandard decays of the SM-like Higgs boson into NLSPs.
[ { "created": "Mon, 3 Nov 2014 07:51:21 GMT", "version": "v1" } ]
2014-11-04
[ [ "Nevzorov", "R.", "" ], [ "Pakvasa", "S.", "" ] ]
We consider the exotic decays of the SM-like Higgs state within the E6 inspired supersymmetric (SUSY) models. In these models the lightest SUSY particle (LSP) can be substantially lighter than 1 eV forming hot dark matter in the Universe. The next--to--lightest SUSY particle (NLSP) also tend to be light. We argue that the NLSP with GeV scale mass may lead to the substantial branching ratio of the nonstandard decays of the SM-like Higgs boson into NLSPs.
2211.05139
Xucheng Gan
Asher Berlin, Jeff A. Dror, Xucheng Gan, Joshua T. Ruderman
Millicharged Relics Reveal Massless Dark Photons
16 pages, 3 appendices, 6 figures; v2, minor improvements to the text, references added, results and conclusions unchanged
JHEP 05 (2023) 046
10.1007/JHEP05(2023)046
FERMILAB-PUB-21-724-SQMS-T
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
The detection of massless kinetically-mixed dark photons is notoriously difficult, as the effect of this mixing can be removed by a field redefinition in vacuum. In this work, we study the prospect of detecting massless dark photons in the presence of a cosmic relic directly charged under this dark electromagnetism. Such millicharged particles, in the form of dark matter or dark radiation, generate an effective dark photon mass that drives photon-to-dark photon oscillations in the early universe. We also study the prospect for such models to alleviate existing cosmological constraints on massive dark photons, enlarging the motivation for direct tests of this parameter space using precision terrestrial probes.
[ { "created": "Wed, 9 Nov 2022 19:00:01 GMT", "version": "v1" }, { "created": "Sun, 7 May 2023 04:07:48 GMT", "version": "v2" } ]
2023-05-09
[ [ "Berlin", "Asher", "" ], [ "Dror", "Jeff A.", "" ], [ "Gan", "Xucheng", "" ], [ "Ruderman", "Joshua T.", "" ] ]
The detection of massless kinetically-mixed dark photons is notoriously difficult, as the effect of this mixing can be removed by a field redefinition in vacuum. In this work, we study the prospect of detecting massless dark photons in the presence of a cosmic relic directly charged under this dark electromagnetism. Such millicharged particles, in the form of dark matter or dark radiation, generate an effective dark photon mass that drives photon-to-dark photon oscillations in the early universe. We also study the prospect for such models to alleviate existing cosmological constraints on massive dark photons, enlarging the motivation for direct tests of this parameter space using precision terrestrial probes.
1512.06647
Takayasu Sekihara
Wen-Chen Chang (Taiwan, Inst. Phys.), S. Kumano (KEK, Tsukuba and J-PARC, Tokai), Takayasu Sekihara (RCNP, Osaka U.)
Constituent-counting rule in photoproduction of hyperon resonances
7 pages, 9 eps figures, version accepted for publication in PRD, discussions improved
null
10.1103/PhysRevD.93.034006
KEK-TH-1881, J-PARC-TH-0047
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the CLAS data on the photoproduction of hyperon resonances, as well as the available data for the ground state $\Lambda$ and $\Sigma ^{0}$ of the CLAS and SLAC-E84 collaborations, by considering constituent-counting rule suggested by perturbative QCD. The counting rule emerges as a scaling behavior of cross sections in hard exclusive reactions with large scattering angles, and it enables us to determine the number of elementary constituents inside hadrons. Therefore, it could be used as a new method for identifying internal constituents of exotic-hadron candidates. From the analyses of the $\gamma \, p \to K^{+} \Lambda$ and $K^{+} \Sigma ^{0}$ reactions, we find that the number of the elementary constituents is consistent with $n_{\gamma} = 1$, $n_{p} = 3$, $n_{K^{+}} = 2$, and $n_{\Lambda} = n_{\Sigma ^{0}} = 3$. Then, the analysis is made for the photoproductions of the hyperon resonances $\Lambda (1405)$, $\Sigma (1385)^{0}$, and $\Lambda (1520)$, where $\Lambda (1405)$ is considered to be a $\bar K N$ molecule and hence its constituent number could be five. However, we find that the current data are not enough to conclude the numbers of their constituent. It is necessary to investigate the higher-energy region at $\sqrt{s} > 2.8$ GeV experimentally beyond the energy of the available CLAS data for counting the number of constituents clearly. We also mention that our results indicate energy dependence in the constituent number, especially for $\Lambda (1405)$. If an excited hyperon is a mixture of three-quark and five-quark states, the energy dependence of the scaling behavior could be valuable for finding its composition and mixture.
[ { "created": "Mon, 21 Dec 2015 14:36:43 GMT", "version": "v1" }, { "created": "Wed, 23 Dec 2015 13:52:08 GMT", "version": "v2" }, { "created": "Fri, 8 Jan 2016 00:37:52 GMT", "version": "v3" } ]
2016-03-23
[ [ "Chang", "Wen-Chen", "", "Taiwan, Inst. Phys." ], [ "Kumano", "S.", "", "KEK, Tsukuba and\n J-PARC, Tokai" ], [ "Sekihara", "Takayasu", "", "RCNP, Osaka U." ] ]
We analyze the CLAS data on the photoproduction of hyperon resonances, as well as the available data for the ground state $\Lambda$ and $\Sigma ^{0}$ of the CLAS and SLAC-E84 collaborations, by considering constituent-counting rule suggested by perturbative QCD. The counting rule emerges as a scaling behavior of cross sections in hard exclusive reactions with large scattering angles, and it enables us to determine the number of elementary constituents inside hadrons. Therefore, it could be used as a new method for identifying internal constituents of exotic-hadron candidates. From the analyses of the $\gamma \, p \to K^{+} \Lambda$ and $K^{+} \Sigma ^{0}$ reactions, we find that the number of the elementary constituents is consistent with $n_{\gamma} = 1$, $n_{p} = 3$, $n_{K^{+}} = 2$, and $n_{\Lambda} = n_{\Sigma ^{0}} = 3$. Then, the analysis is made for the photoproductions of the hyperon resonances $\Lambda (1405)$, $\Sigma (1385)^{0}$, and $\Lambda (1520)$, where $\Lambda (1405)$ is considered to be a $\bar K N$ molecule and hence its constituent number could be five. However, we find that the current data are not enough to conclude the numbers of their constituent. It is necessary to investigate the higher-energy region at $\sqrt{s} > 2.8$ GeV experimentally beyond the energy of the available CLAS data for counting the number of constituents clearly. We also mention that our results indicate energy dependence in the constituent number, especially for $\Lambda (1405)$. If an excited hyperon is a mixture of three-quark and five-quark states, the energy dependence of the scaling behavior could be valuable for finding its composition and mixture.
2405.20280
Xiaojun Yao
Di-Lun Yang and Xiaojun Yao
Quarkonium Polarization in Medium from Open Quantum Systems and Chromomagnetic Correlators
37 pages
null
null
IQuS@UW-21-079
hep-ph nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the spin-dependent in-medium dynamics of quarkonia by using the potential nonrelativistic QCD (pNRQCD) and the open quantum system framework. We consider the pNRQCD Lagrangian valid up to the order $\frac{r}{M^0}=r$ and $\frac{r^0}{M}=\frac{1}{M}$ in the double power counting. By considering the Markovian condition and applying the Wigner transformation upon the diagonal spin components of the quarkonium density matrix with the semiclassical expansion, we systematically derive the Boltzmann transport equation for quarkonia with polarization dependence in the quantum optical limit. Unlike the spin-independent collision terms governed by certain chromoelectric field correlators, new gauge invariant correlators of chromomagnetic fields determine the recombination and dissociation terms with polarization dependence at the order we are working. We also derive a Lindblad equation describing the in-medium transitions between spin-singlet and spin-triplet heavy quark-antiquark pairs in the quantum Brownian motion limit. The Lindblad equation is governed by new transport coefficients defined in terms of the chromomagnetic field correlators. Our formalism is generic and valid for both weakly-coupled and strongly-coupled quark gluon plasmas. It can be further applied to study spin alignment of vector quarkonia in heavy ion collisions.
[ { "created": "Thu, 30 May 2024 17:33:38 GMT", "version": "v1" } ]
2024-05-31
[ [ "Yang", "Di-Lun", "" ], [ "Yao", "Xiaojun", "" ] ]
We study the spin-dependent in-medium dynamics of quarkonia by using the potential nonrelativistic QCD (pNRQCD) and the open quantum system framework. We consider the pNRQCD Lagrangian valid up to the order $\frac{r}{M^0}=r$ and $\frac{r^0}{M}=\frac{1}{M}$ in the double power counting. By considering the Markovian condition and applying the Wigner transformation upon the diagonal spin components of the quarkonium density matrix with the semiclassical expansion, we systematically derive the Boltzmann transport equation for quarkonia with polarization dependence in the quantum optical limit. Unlike the spin-independent collision terms governed by certain chromoelectric field correlators, new gauge invariant correlators of chromomagnetic fields determine the recombination and dissociation terms with polarization dependence at the order we are working. We also derive a Lindblad equation describing the in-medium transitions between spin-singlet and spin-triplet heavy quark-antiquark pairs in the quantum Brownian motion limit. The Lindblad equation is governed by new transport coefficients defined in terms of the chromomagnetic field correlators. Our formalism is generic and valid for both weakly-coupled and strongly-coupled quark gluon plasmas. It can be further applied to study spin alignment of vector quarkonia in heavy ion collisions.
2008.12163
HongWei Ke
Hong-Wei Ke and Xue-Qian Li
A natural interpretation on the data of $\Lambda_c\to\Sigma\pi$
11 pages, 1 figure and 5 tables
Phys. Rev. D 102, 113013 (2020)
10.1103/PhysRevD.102.113013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Even though the Standard Model (SM) has achieved great success, its application to the field of low energies still lacks solid foundation due to our limited knowledge on non-perturbative QCD. Practically, all theoretical calculations of the hadronic transition matrix elements are based various phenomenological models. There indeed exist some anomalies in the field which are waiting for interpretations. The goal of this work is trying to solve one of the anomalies: the discrepancy between the theoretical prediction on the sign of the up-down asymmetry parameter of $\Lambda_c\to\Sigma\pi$ and the experimental measurement. In the literatures several authors calculated the rate and determined the asymmetry parameter within various schemes, but there exist obvious loopholes in those adopted scenarios. To solve the discrepancy between theory and data, we suggest that not only the direct transition process contributes to the observed $\Lambda_c\to\Sigma\pi$, but also other portals such as $\Lambda_c\to \Lambda\rho$ also play a substantial role via an isospin-conserving re-scattering $\Lambda\rho\to\Sigma\pi$. Taking into account of the effects induced by the final state interaction, we re-evaluate the relevant quantities. Our numerical results indicate that the new theoretical prediction based on this scenario involving an interference between the direct transition of $\Lambda_c\to\Sigma\pi$ and the portal $\Lambda_c\to\Lambda\rho\to\Sigma\pi$ can make both the decay rate and sign of the asymmetry parameter to be consistent with data.
[ { "created": "Thu, 27 Aug 2020 14:41:50 GMT", "version": "v1" } ]
2021-01-04
[ [ "Ke", "Hong-Wei", "" ], [ "Li", "Xue-Qian", "" ] ]
Even though the Standard Model (SM) has achieved great success, its application to the field of low energies still lacks solid foundation due to our limited knowledge on non-perturbative QCD. Practically, all theoretical calculations of the hadronic transition matrix elements are based various phenomenological models. There indeed exist some anomalies in the field which are waiting for interpretations. The goal of this work is trying to solve one of the anomalies: the discrepancy between the theoretical prediction on the sign of the up-down asymmetry parameter of $\Lambda_c\to\Sigma\pi$ and the experimental measurement. In the literatures several authors calculated the rate and determined the asymmetry parameter within various schemes, but there exist obvious loopholes in those adopted scenarios. To solve the discrepancy between theory and data, we suggest that not only the direct transition process contributes to the observed $\Lambda_c\to\Sigma\pi$, but also other portals such as $\Lambda_c\to \Lambda\rho$ also play a substantial role via an isospin-conserving re-scattering $\Lambda\rho\to\Sigma\pi$. Taking into account of the effects induced by the final state interaction, we re-evaluate the relevant quantities. Our numerical results indicate that the new theoretical prediction based on this scenario involving an interference between the direct transition of $\Lambda_c\to\Sigma\pi$ and the portal $\Lambda_c\to\Lambda\rho\to\Sigma\pi$ can make both the decay rate and sign of the asymmetry parameter to be consistent with data.
1705.06330
Reza Moazzemi
Mohammadmahdi Ettefaghi, Reza Moazzemi, Mohsen Rousta
Constraining unparticle physics from $CP$ violation in Cabibbo-favored decays of D mesons
10 pages, revtex4-1 style, to appear in PRD
Phys. Rev. D 95, 095027 (2017)
10.1103/PhysRevD.95.095027
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
According to the standard model, the Cabibbo-favored (CF) decays are $CP$ conserve at tree level. Observation of any finite $CP$ asymmetry can be received as a signal of new physics. In CF charm meson decays, $ D^0 \rightarrow K^- \pi^+ $ and $ D^+ \rightarrow K_s^0 \pi^+ $, the following experimental values for their $CP$ asymmetry are reported, respectively: ($0.3 \pm 0.7$) % and ($-0.41 \pm 0.09$) %. The value of the later can be attributed to the mixing of $ K^0 $ and $ \overline{K^0} $, however, its contribution is about ($-0.332 \pm 0.006 $) %. In this paper, we use these experimental results to constrain the unparticle stuff as a new physics which may contribute to these $CP$ asymmetries.
[ { "created": "Wed, 17 May 2017 20:06:02 GMT", "version": "v1" } ]
2018-11-16
[ [ "Ettefaghi", "Mohammadmahdi", "" ], [ "Moazzemi", "Reza", "" ], [ "Rousta", "Mohsen", "" ] ]
According to the standard model, the Cabibbo-favored (CF) decays are $CP$ conserve at tree level. Observation of any finite $CP$ asymmetry can be received as a signal of new physics. In CF charm meson decays, $ D^0 \rightarrow K^- \pi^+ $ and $ D^+ \rightarrow K_s^0 \pi^+ $, the following experimental values for their $CP$ asymmetry are reported, respectively: ($0.3 \pm 0.7$) % and ($-0.41 \pm 0.09$) %. The value of the later can be attributed to the mixing of $ K^0 $ and $ \overline{K^0} $, however, its contribution is about ($-0.332 \pm 0.006 $) %. In this paper, we use these experimental results to constrain the unparticle stuff as a new physics which may contribute to these $CP$ asymmetries.
1709.08002
Shi Pu
Yang-guang Yang, Shi Pu
Thermal vorticity production in relativistic dissipative fluids
Presented by S. Pu at Critical Point and Onset of Deconfinement (CPOD), Wroclaw, Poland, May 30 - June 4, 2016
null
10.5506/APhysPolBSupp.10.771
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have computed the circulation integrations of thermal vorticity with and without charged currents in dissipative fluids. We find that the relativistic Kelvin circulation theorem will be modified by the dissipative effects, therefore, the circulation integrations of thermal vorticity may not be conserved during the fluid evolution.
[ { "created": "Sat, 23 Sep 2017 04:31:42 GMT", "version": "v1" } ]
2017-09-26
[ [ "Yang", "Yang-guang", "" ], [ "Pu", "Shi", "" ] ]
We have computed the circulation integrations of thermal vorticity with and without charged currents in dissipative fluids. We find that the relativistic Kelvin circulation theorem will be modified by the dissipative effects, therefore, the circulation integrations of thermal vorticity may not be conserved during the fluid evolution.
2210.13141
Jing-Yu Zhu
Maksym Ovchynnikov, Thomas Schwetz and Jing-Yu Zhu
Dipole portal and neutrinophilic scalars at DUNE revisited: the importance of the high-energy neutrino tail
22 pages, 13 figures, consistent with published version
null
10.1103/PhysRevD.107.055029
null
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
We estimate the sensitivity of the DUNE experiment to new physics particles interacting with neutrinos, considering the dipole portal to heavy neutral leptons and a neutrinophilic scalar with lepton-number $2$ as examples. We demonstrate that neutrinos from the high-energy tail of the DUNE flux, with energies $E_{\nu}\gtrsim 5-10\text{ GeV}$, may significantly improve the sensitivity to these models, allowing to search for particles as heavy as $\simeq 10\text{ GeV}$. We also study the impact of the so-called tau-optimized neutrino beam configuration, which slightly improves sensitivity to the new physics models considered here. For both models, we consider new production channels (such as deep-inelastic scattering) and provide a detailed comparison of different signatures in the detector.
[ { "created": "Mon, 24 Oct 2022 11:52:20 GMT", "version": "v1" }, { "created": "Sun, 26 Mar 2023 13:57:35 GMT", "version": "v2" } ]
2023-04-05
[ [ "Ovchynnikov", "Maksym", "" ], [ "Schwetz", "Thomas", "" ], [ "Zhu", "Jing-Yu", "" ] ]
We estimate the sensitivity of the DUNE experiment to new physics particles interacting with neutrinos, considering the dipole portal to heavy neutral leptons and a neutrinophilic scalar with lepton-number $2$ as examples. We demonstrate that neutrinos from the high-energy tail of the DUNE flux, with energies $E_{\nu}\gtrsim 5-10\text{ GeV}$, may significantly improve the sensitivity to these models, allowing to search for particles as heavy as $\simeq 10\text{ GeV}$. We also study the impact of the so-called tau-optimized neutrino beam configuration, which slightly improves sensitivity to the new physics models considered here. For both models, we consider new production channels (such as deep-inelastic scattering) and provide a detailed comparison of different signatures in the detector.
1803.08080
Sophie Renner
Sophie Renner and Pedro Schwaller
A flavoured dark sector
32 pages, 14 figures. v2: Amended references
null
10.1007/JHEP08(2018)052
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the phenomenology of a QCD-like dark sector which confines around the GeV scale. The dark sector inherits a flavour structure from a coupling between dark quarks and SM quarks via a heavy mediator, which leads to exciting new phenomena. While stable baryonic bound states are the dark matter candidates, the phenomenology is dominated by the lightest composite mesons, the dark pions, which can have decay lengths ranging from millimetres to hundreds of meters. For masses below 1.5 GeV, their exclusive decays to SM mesons are calculated for the first time by matching both dark and visible sectors to a chiral Lagrangian. Constraints from big bang nucleosynthesis, dark matter direct detection and flavour single out a small region of allowed parameter space for dark pion masses below 5 GeV. It is best probed by the fixed target experiments NA62 and SHiP, where dark pions can be produced copiously in rare decays like B to K piD. Heavier dark pions are best searched for at the LHC, where they decay after hadronisation to produce jets which emerge into SM states within the detector. Here the flavour structure ensures different flavours emerge on different length scales, leading to a striking new feature in the emerging jets signature.
[ { "created": "Wed, 21 Mar 2018 18:37:02 GMT", "version": "v1" }, { "created": "Fri, 6 Apr 2018 00:00:36 GMT", "version": "v2" } ]
2018-08-29
[ [ "Renner", "Sophie", "" ], [ "Schwaller", "Pedro", "" ] ]
We explore the phenomenology of a QCD-like dark sector which confines around the GeV scale. The dark sector inherits a flavour structure from a coupling between dark quarks and SM quarks via a heavy mediator, which leads to exciting new phenomena. While stable baryonic bound states are the dark matter candidates, the phenomenology is dominated by the lightest composite mesons, the dark pions, which can have decay lengths ranging from millimetres to hundreds of meters. For masses below 1.5 GeV, their exclusive decays to SM mesons are calculated for the first time by matching both dark and visible sectors to a chiral Lagrangian. Constraints from big bang nucleosynthesis, dark matter direct detection and flavour single out a small region of allowed parameter space for dark pion masses below 5 GeV. It is best probed by the fixed target experiments NA62 and SHiP, where dark pions can be produced copiously in rare decays like B to K piD. Heavier dark pions are best searched for at the LHC, where they decay after hadronisation to produce jets which emerge into SM states within the detector. Here the flavour structure ensures different flavours emerge on different length scales, leading to a striking new feature in the emerging jets signature.
hep-ph/9410327
null
A. Brandenburg, V. V. Khoze and D. M\"uller
Semi-Exclusive Pion Production in Deep-Inelastic Scattering
10 pages,PLAIN TEX, 4 figs. appended as compressed and uuencoded PS file, SLAC-PUB-6688
Phys.Lett. B347 (1995) 413-418
10.1016/0370-2693(95)00064-R
null
hep-ph
null
We calculate azimuthal asymmetries and the Callan-Gross $R$-ratio for semi-exclusive pion production in deep inelastic scattering taking into account higher twist effects. Our results are qualitatively different from the QCD-improved parton model predictions for semi-inclusive deep inelastic scattering.
[ { "created": "Thu, 20 Oct 1994 00:30:00 GMT", "version": "v1" } ]
2009-10-28
[ [ "Brandenburg", "A.", "" ], [ "Khoze", "V. V.", "" ], [ "Müller", "D.", "" ] ]
We calculate azimuthal asymmetries and the Callan-Gross $R$-ratio for semi-exclusive pion production in deep inelastic scattering taking into account higher twist effects. Our results are qualitatively different from the QCD-improved parton model predictions for semi-inclusive deep inelastic scattering.
1112.6021
Zhong-Bo Kang
Zhong-Bo Kang, Ivan Vitev, Hongxi Xing
Dihadron momentum imbalance and correlations in d+Au collisions
12 pages, 6 figures
Phys.Rev. D85 (2012) 054024
10.1103/PhysRevD.85.054024
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate in perturbative QCD the transverse momentum imbalance of dijet and dihadron production in high energy p+A (d+A) collisions. We evaluate the effect of both initial- and final-state multiple scattering, which determines the strength of this transverse momentum imbalance. Combining this new result with the suppression of the cross section in d+Au collisions, which arises from cold nuclear matter energy loss and coherent power corrections, we are able to describe the dihadron correlations measured by both PHENIX and STAR collaborations at RHIC, including mid-mid, mid-forward, and forward-forward rapidity hadron pairs.
[ { "created": "Tue, 27 Dec 2011 21:00:49 GMT", "version": "v1" } ]
2012-03-29
[ [ "Kang", "Zhong-Bo", "" ], [ "Vitev", "Ivan", "" ], [ "Xing", "Hongxi", "" ] ]
We calculate in perturbative QCD the transverse momentum imbalance of dijet and dihadron production in high energy p+A (d+A) collisions. We evaluate the effect of both initial- and final-state multiple scattering, which determines the strength of this transverse momentum imbalance. Combining this new result with the suppression of the cross section in d+Au collisions, which arises from cold nuclear matter energy loss and coherent power corrections, we are able to describe the dihadron correlations measured by both PHENIX and STAR collaborations at RHIC, including mid-mid, mid-forward, and forward-forward rapidity hadron pairs.
0907.1498
Andre Sopczak
Andre Sopczak
Cross-sections and branching ratios for charged Higgs searches
8 pages, contribution to the Workshop on Prospects for Charged Higgs Discovery at Colliders, 16-19 September 2008, Uppsala, Sweden
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For the preparation of the experimental search for charged Higgs bosons at the LHC detailed studies have been made to determine the expected charged Higgs boson production cross-sections and decay branching ratios at sqrts = 14 TeV. In the mass regime below the t-quark mass the expected production cross-sections are discussed using PYTHIA and FeynHiggs program packages based on the decay t to H^+b. For higher masses Next-to-Leading-Order (NLO calculations have been used, and particular attention has been given to the intermediate-mass region. The decay branching ratios have been studied with the program packages FeynHiggs and HDecay. Higher-order corrections (Delta_b corrections) in the MSSM are consistently taken into account. Two benchmark scenarios are considered, one of them the `mhmax'.
[ { "created": "Thu, 9 Jul 2009 10:57:32 GMT", "version": "v1" } ]
2009-07-10
[ [ "Sopczak", "Andre", "" ] ]
For the preparation of the experimental search for charged Higgs bosons at the LHC detailed studies have been made to determine the expected charged Higgs boson production cross-sections and decay branching ratios at sqrts = 14 TeV. In the mass regime below the t-quark mass the expected production cross-sections are discussed using PYTHIA and FeynHiggs program packages based on the decay t to H^+b. For higher masses Next-to-Leading-Order (NLO calculations have been used, and particular attention has been given to the intermediate-mass region. The decay branching ratios have been studied with the program packages FeynHiggs and HDecay. Higher-order corrections (Delta_b corrections) in the MSSM are consistently taken into account. Two benchmark scenarios are considered, one of them the `mhmax'.
1007.3750
Carla Biggio
Carla Biggio, Lorenzo Calibbi
Phenomenology of SUSY SU(5) with type I+III seesaw
12 pages, 6 figures; v2: minor changes, comparison with type I and II seesaws added, references added, version to appear on JHEP
JHEP 1010:037,2010
10.1007/JHEP10(2010)037
MPP-2010-109
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a supersymmetric SU(5) model where two neutrino masses are obtained via a mixed type I+III seesaw mechanism induced by the component fields of a single SU(5) adjoint. We have analyzed the phenomenology of the model paying particular attention to flavour violating processes and dark matter relic density, assuming universal boundary conditions. We have found that, for a seesaw scale larger than $10^{12\div 13}$ GeV, BR$(\mu\to e \gamma)$ is in the reach of the MEG experiment in sizable regions of the parameter space. On the other side, current bounds on it force BR$(\tau \to \mu \gamma)$ to be well below the reach of forthcoming experiments, rendering thus the model disprovable if a positive signal is found. The same bounds still allow for a sizable positive contribution to $\epsilon_K$, while the CP violation in the $B_s$ mixing turns out to be too small to account for the di-muon anomaly reported by the D0 collaboration. Finally, the regions where the neutralino relic density is within the WMAP bounds can be strongly modified with respect to the constrained MSSM case. In particular, a peculiar coannihilation region, bounded from above, can be realized, which allows us to put an upper bound on the dark matter mass for certain set-ups of the parameters.
[ { "created": "Wed, 21 Jul 2010 20:18:30 GMT", "version": "v1" }, { "created": "Mon, 20 Sep 2010 12:40:09 GMT", "version": "v2" } ]
2014-11-21
[ [ "Biggio", "Carla", "" ], [ "Calibbi", "Lorenzo", "" ] ]
We consider a supersymmetric SU(5) model where two neutrino masses are obtained via a mixed type I+III seesaw mechanism induced by the component fields of a single SU(5) adjoint. We have analyzed the phenomenology of the model paying particular attention to flavour violating processes and dark matter relic density, assuming universal boundary conditions. We have found that, for a seesaw scale larger than $10^{12\div 13}$ GeV, BR$(\mu\to e \gamma)$ is in the reach of the MEG experiment in sizable regions of the parameter space. On the other side, current bounds on it force BR$(\tau \to \mu \gamma)$ to be well below the reach of forthcoming experiments, rendering thus the model disprovable if a positive signal is found. The same bounds still allow for a sizable positive contribution to $\epsilon_K$, while the CP violation in the $B_s$ mixing turns out to be too small to account for the di-muon anomaly reported by the D0 collaboration. Finally, the regions where the neutralino relic density is within the WMAP bounds can be strongly modified with respect to the constrained MSSM case. In particular, a peculiar coannihilation region, bounded from above, can be realized, which allows us to put an upper bound on the dark matter mass for certain set-ups of the parameters.
1103.1688
Hong-Lei Li
Shou-Shan Bao, Hong-Lei Li, Zong-Guo Si, Yu-Feng Zhou
Probing $W^\prime_L WH$ and $W^\prime_R W H$ Interaction at LHC
null
Phys.Rev.D83:115001,2011
10.1103/PhysRevD.83.115001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many new physics models predict the existence of TeV-scale charged gauge boson $W^\prime$ together with Higgs boson(s). We study the $W^\prime WH$ interaction and explore the angular distribution of charged lepton to distinguish $W_R^\prime WH$ from $W_L^\prime WH$ in $pp\to HW\to b \bar b l \nu$ process at the LHC. It is found that a new type forward-backward asymmetry($A_{FB}$) relating to the angle between the direction of the charged lepton in $W$ rest frame and that of the reconstructed $W^\prime$ in laboratory frame is useful to investigate the properties of $W^\prime W H$ interaction. We analyze the Standard Model backgrounds and develop a set of cuts to highlight the signal and suppress the backgrounds at LHC. We find that $A_{FB}$ can reach 0.03(-0.07) for $W_R^\prime$($W_L^\prime$) production at $\sqrt{S}=14$ TeV.
[ { "created": "Wed, 9 Mar 2011 01:53:42 GMT", "version": "v1" }, { "created": "Fri, 13 May 2011 03:51:34 GMT", "version": "v2" }, { "created": "Wed, 8 Jun 2011 00:48:44 GMT", "version": "v3" } ]
2011-06-13
[ [ "Bao", "Shou-Shan", "" ], [ "Li", "Hong-Lei", "" ], [ "Si", "Zong-Guo", "" ], [ "Zhou", "Yu-Feng", "" ] ]
Many new physics models predict the existence of TeV-scale charged gauge boson $W^\prime$ together with Higgs boson(s). We study the $W^\prime WH$ interaction and explore the angular distribution of charged lepton to distinguish $W_R^\prime WH$ from $W_L^\prime WH$ in $pp\to HW\to b \bar b l \nu$ process at the LHC. It is found that a new type forward-backward asymmetry($A_{FB}$) relating to the angle between the direction of the charged lepton in $W$ rest frame and that of the reconstructed $W^\prime$ in laboratory frame is useful to investigate the properties of $W^\prime W H$ interaction. We analyze the Standard Model backgrounds and develop a set of cuts to highlight the signal and suppress the backgrounds at LHC. We find that $A_{FB}$ can reach 0.03(-0.07) for $W_R^\prime$($W_L^\prime$) production at $\sqrt{S}=14$ TeV.
2407.14592
Jes\'us Luque Del Castillo
Jose A. R. Cembranos, Jes\'us Luque and Javier Rubio
Scalar Dark Matter Production through the Bubble Expansion Mechanism: The Boosting Role of Non-Renormalizable Interactions
11 pages, 6 figures
null
null
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a Bubble Expansion mechanism for the production of scalar dark matter during a first-order phase transition in the early Universe. Seeking for a dark matter energy density in agreement with observations, we study different non-renormalizable interactions between the dark matter species and the field undergoing the transition. The resulting relic abundance is shown to display a strong dependence on the Lorentz boost factor associated to the bubble wall motion, with this dependence becoming more significant the higher the dimension of the non-renormalizable interaction. This allows for observational compatibility across a wide range of dark matter masses and transition temperatures, typically excluded in renormalizable scenarios. For a transition around the electroweak scale, the associated gravitational wave spectrum is also within the reach of future detectors.
[ { "created": "Fri, 19 Jul 2024 18:00:01 GMT", "version": "v1" } ]
2024-07-23
[ [ "Cembranos", "Jose A. R.", "" ], [ "Luque", "Jesús", "" ], [ "Rubio", "Javier", "" ] ]
We consider a Bubble Expansion mechanism for the production of scalar dark matter during a first-order phase transition in the early Universe. Seeking for a dark matter energy density in agreement with observations, we study different non-renormalizable interactions between the dark matter species and the field undergoing the transition. The resulting relic abundance is shown to display a strong dependence on the Lorentz boost factor associated to the bubble wall motion, with this dependence becoming more significant the higher the dimension of the non-renormalizable interaction. This allows for observational compatibility across a wide range of dark matter masses and transition temperatures, typically excluded in renormalizable scenarios. For a transition around the electroweak scale, the associated gravitational wave spectrum is also within the reach of future detectors.
2103.02592
Rajeev Singh Mr.
Rajeev Singh, Masoud Shokri, and Radoslaw Ryblewski
Spin polarization dynamics in the Bjorken-expanding resistive MHD background
12 pages, 6 figures; Accepted version; Comments are very much welcome!
Phys. Rev. D 103, 094034 (2021)
10.1103/PhysRevD.103.094034
null
hep-ph hep-th nucl-th
http://creativecommons.org/licenses/by/4.0/
Evolution of spin polarization in the presence of external electric field is studied for collision energies $\sqrt{s_{\rm NN}}=27\,{\rm GeV}$ and $\sqrt{s_{\rm NN}}=200\,{\rm GeV}$. The numerical analysis is done in the perfect-fluid Bjorken-expanding resistive magnetohydrodynamic background and novel results are reported. In particular, we show that the electric field plays a significant role in the competition between expansion and dissipation.
[ { "created": "Sat, 27 Feb 2021 15:05:05 GMT", "version": "v1" }, { "created": "Fri, 21 May 2021 06:45:42 GMT", "version": "v2" } ]
2021-06-02
[ [ "Singh", "Rajeev", "" ], [ "Shokri", "Masoud", "" ], [ "Ryblewski", "Radoslaw", "" ] ]
Evolution of spin polarization in the presence of external electric field is studied for collision energies $\sqrt{s_{\rm NN}}=27\,{\rm GeV}$ and $\sqrt{s_{\rm NN}}=200\,{\rm GeV}$. The numerical analysis is done in the perfect-fluid Bjorken-expanding resistive magnetohydrodynamic background and novel results are reported. In particular, we show that the electric field plays a significant role in the competition between expansion and dissipation.
1801.05561
Stephen Lonsdale
Stephen J. Lonsdale and Raymond R. Volkas
Comprehensive asymmetric dark matter model
45 pages, 11 figures. Matches published version
Phys. Rev. D 97, 103510 (2018)
10.1103/PhysRevD.97.103510
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical constraints. Importantly, it incorporates a deep reason for why the dark matter mass scale is related to the proton mass, a key consideration in ADM models. Our starting point is the idea of mirror matter, which offers an explanation for dark matter by duplicating the standard model with a dark sector related by a $Z_2$ parity symmetry. However, the dark sector need not manifest as a symmetric copy of the standard model in the present day. By utilising the mechanism of "asymmetric symmetry breaking" with two Higgs doublets in each sector, we develop a model of ADM where the mirror symmetry is spontaneously broken, leading to an electroweak scale in the dark sector that is significantly larger than that of the visible sector. The weak sensitivity of the ordinary and dark QCD confinement scales to their respective electroweak scales leads to the necessary connection between the dark matter and proton masses. The dark matter is composed of either dark neutrons or a mixture of dark neutrons and metastable dark hydrogen atoms. Lepton asymmetries are generated by the $CP$-violating decays of heavy Majorana neutrinos in both sectors. These are then converted by sphaleron processes to produce the observed ratio of visible to dark matter in the universe. The dynamics responsible for the kinetic decoupling of the two sectors emerges as an important issue that we only partially solve.
[ { "created": "Wed, 17 Jan 2018 05:55:02 GMT", "version": "v1" }, { "created": "Wed, 7 Feb 2018 04:20:45 GMT", "version": "v2" }, { "created": "Tue, 22 May 2018 05:33:07 GMT", "version": "v3" } ]
2018-05-23
[ [ "Lonsdale", "Stephen J.", "" ], [ "Volkas", "Raymond R.", "" ] ]
Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical constraints. Importantly, it incorporates a deep reason for why the dark matter mass scale is related to the proton mass, a key consideration in ADM models. Our starting point is the idea of mirror matter, which offers an explanation for dark matter by duplicating the standard model with a dark sector related by a $Z_2$ parity symmetry. However, the dark sector need not manifest as a symmetric copy of the standard model in the present day. By utilising the mechanism of "asymmetric symmetry breaking" with two Higgs doublets in each sector, we develop a model of ADM where the mirror symmetry is spontaneously broken, leading to an electroweak scale in the dark sector that is significantly larger than that of the visible sector. The weak sensitivity of the ordinary and dark QCD confinement scales to their respective electroweak scales leads to the necessary connection between the dark matter and proton masses. The dark matter is composed of either dark neutrons or a mixture of dark neutrons and metastable dark hydrogen atoms. Lepton asymmetries are generated by the $CP$-violating decays of heavy Majorana neutrinos in both sectors. These are then converted by sphaleron processes to produce the observed ratio of visible to dark matter in the universe. The dynamics responsible for the kinetic decoupling of the two sectors emerges as an important issue that we only partially solve.
hep-ph/9802301
null
J.Soffer
Polarized Parton Distributions and QCD Spin Tests at RHIC-BNL
Latex file, 12 pages and 6 fig included with psfig.sty.,use appb style. To appear in the Proceedings of The Cracow Epiphany Conference on Spin Effects in Particle Physics, Cracow, Poland, January 9-11, 1998
Acta Phys.Polon. B29 (1998) 1303-1314
null
CPT-98/P3618
hep-ph
null
The RHIC facility at BNL will be operating soon, part of the year, as a polarized proton-proton collider. This will allow the undertaking of a vast spin physics programme, mainly by the two large detectors PHENIX and STAR. We review some theoretical aspects of this research programme which will allow, firstly to improve our present knowledge on polarized quark, gluon and sea distributions in a nucleon, secondly to perform novel QCD spin tests and finally, perhaps, to uncover some new physics.
[ { "created": "Wed, 11 Feb 1998 15:46:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Soffer", "J.", "" ] ]
The RHIC facility at BNL will be operating soon, part of the year, as a polarized proton-proton collider. This will allow the undertaking of a vast spin physics programme, mainly by the two large detectors PHENIX and STAR. We review some theoretical aspects of this research programme which will allow, firstly to improve our present knowledge on polarized quark, gluon and sea distributions in a nucleon, secondly to perform novel QCD spin tests and finally, perhaps, to uncover some new physics.
1703.09226
Andreas Crivellin
Andreas Crivellin, Dario M\"uller and Toshihiko Ota
Simultaneous Explanation of $R(D^{(*)})$ and $b\to s\mu^+\mu^-$: The Last Scalar Leptoquarks Standing
8 pages, 4 figures, version accepted for publication in JHEP
null
10.1007/JHEP09(2017)040
PSI-PR-17-04, YACHAY-PUB-17-03-PN, ZU-TH 05/17
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Over the past years, experiments accumulated intriguing hints for new physics (NP) in flavor observables, namely in the anomalous magnetic moment of the muon ($a_\mu$), in $R(D^{(*)})={\rm Br}(B\to D^{(*)}\tau\nu)/{\rm Br}(B\to D^{(*)}\ell\nu)$ and in $b\to s\mu^+\mu^-$ transitions, which are all at the $3-4\,\sigma$ level. In this article we point out that one can explain the $R(D^{(*)})$ anomaly using two scalar leptoquarks (LQs) with the same mass and coupling to fermions related via a discrete symmetry: an $SU(2)$ singlet and an $SU(2)$ triplet, both with hypercharge $Y=-2/3$. In this way, potentially dangerous contributions to $b\to s\nu\nu$ are avoided and non-CKM suppressed effects in $R(D^{(*)})$ can be generated. This allows for smaller overall couplings to fermions weakening the direct LHC bounds. In our model, $R(D^{(*)})$ is directly correlated to $b\to s\tau^+\tau^-$ transitions where an enhancement by orders of magnitude compared to the standard model (SM) is predicted, such that these decay modes are in the reach of LHCb and BELLE II. Furthermore, one can also naturally explain the $b\to s\mu^+\mu^-$ anomalies (including $R(K)$) by a $C_9=-C_{10}$ like contribution without spoiling $\mu-e$ universality in charged current decays. In this case sizable effects in $b\to s\tau\mu$ transitions are predicted which are again well within the experimental reach. One can even address the longstanding anomaly in $a_\mu$, generating a sizable decay rate for $\tau\to\mu\gamma$. However, we find that out of the three anomalies $R(D^{(*)})$, $b\to s\mu^+\mu^-$ and $a_{\mu}$ only two (but any two) can be explained simultaneously.
[ { "created": "Mon, 27 Mar 2017 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2017 14:39:19 GMT", "version": "v2" }, { "created": "Tue, 5 Sep 2017 14:15:13 GMT", "version": "v3" } ]
2017-10-11
[ [ "Crivellin", "Andreas", "" ], [ "Müller", "Dario", "" ], [ "Ota", "Toshihiko", "" ] ]
Over the past years, experiments accumulated intriguing hints for new physics (NP) in flavor observables, namely in the anomalous magnetic moment of the muon ($a_\mu$), in $R(D^{(*)})={\rm Br}(B\to D^{(*)}\tau\nu)/{\rm Br}(B\to D^{(*)}\ell\nu)$ and in $b\to s\mu^+\mu^-$ transitions, which are all at the $3-4\,\sigma$ level. In this article we point out that one can explain the $R(D^{(*)})$ anomaly using two scalar leptoquarks (LQs) with the same mass and coupling to fermions related via a discrete symmetry: an $SU(2)$ singlet and an $SU(2)$ triplet, both with hypercharge $Y=-2/3$. In this way, potentially dangerous contributions to $b\to s\nu\nu$ are avoided and non-CKM suppressed effects in $R(D^{(*)})$ can be generated. This allows for smaller overall couplings to fermions weakening the direct LHC bounds. In our model, $R(D^{(*)})$ is directly correlated to $b\to s\tau^+\tau^-$ transitions where an enhancement by orders of magnitude compared to the standard model (SM) is predicted, such that these decay modes are in the reach of LHCb and BELLE II. Furthermore, one can also naturally explain the $b\to s\mu^+\mu^-$ anomalies (including $R(K)$) by a $C_9=-C_{10}$ like contribution without spoiling $\mu-e$ universality in charged current decays. In this case sizable effects in $b\to s\tau\mu$ transitions are predicted which are again well within the experimental reach. One can even address the longstanding anomaly in $a_\mu$, generating a sizable decay rate for $\tau\to\mu\gamma$. However, we find that out of the three anomalies $R(D^{(*)})$, $b\to s\mu^+\mu^-$ and $a_{\mu}$ only two (but any two) can be explained simultaneously.
1805.08659
Brian Maddock
Wolfgang Altmannshofer, Brian Maddock
Flavorful Two Higgs Doublet Models with a Twist
42 pages, 8 figures, 4 tables
Phys. Rev. D 98, 075005 (2018)
10.1103/PhysRevD.98.075005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore Two Higgs Doublet Models with non-standard flavor structures. In analogy to the four, well studied, models with natural flavor conservation (type 1, type 2, lepton-specific, flipped), we identify four models that preserve an approximate $U(2)^5$ flavor symmetry acting on the first two generations. In all four models, the couplings of the 125 GeV Higgs are modified in characteristic flavor non-universal ways. The heavy neutral and charged Higgs bosons show an interesting non-standard phenomenology. We discuss their production and decay modes and identify the most sensitive search channels at the LHC. We study the effects on low energy flavor violating processes finding relevant constraints from $B_d$ and $B_s$ meson oscillations and from the rare decay $B_s \to \mu^+ \mu^-$. We also find that lepton flavor violating $B$ meson decays like $B_s \to \tau \mu$ and $B \to K^{(*)} \tau \mu$ might have branching ratios at an observable level.
[ { "created": "Tue, 22 May 2018 15:18:50 GMT", "version": "v1" }, { "created": "Tue, 6 Nov 2018 19:47:27 GMT", "version": "v2" } ]
2018-11-08
[ [ "Altmannshofer", "Wolfgang", "" ], [ "Maddock", "Brian", "" ] ]
We explore Two Higgs Doublet Models with non-standard flavor structures. In analogy to the four, well studied, models with natural flavor conservation (type 1, type 2, lepton-specific, flipped), we identify four models that preserve an approximate $U(2)^5$ flavor symmetry acting on the first two generations. In all four models, the couplings of the 125 GeV Higgs are modified in characteristic flavor non-universal ways. The heavy neutral and charged Higgs bosons show an interesting non-standard phenomenology. We discuss their production and decay modes and identify the most sensitive search channels at the LHC. We study the effects on low energy flavor violating processes finding relevant constraints from $B_d$ and $B_s$ meson oscillations and from the rare decay $B_s \to \mu^+ \mu^-$. We also find that lepton flavor violating $B$ meson decays like $B_s \to \tau \mu$ and $B \to K^{(*)} \tau \mu$ might have branching ratios at an observable level.
hep-ph/9710387
Sergei Chekanov
S.V.Chekanov
Local Properties of Local Multiplicity Distributions
LaTeX, 12 pages, 4 eps figures, Presented at the International School-Seminar "The actual problems of particle physics" (NCPHEP-Dubna) Gomel, Belarus, August 8-17, 1997
null
null
null
hep-ph
null
Some aspects of applications of bunching parameters are discussed. It is investigated to what extent Monte-Carlo models, which have been tuned to reproduce global event-shape variables and single-particle inclusive distributions, agree with each other.
[ { "created": "Fri, 17 Oct 1997 12:43:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Chekanov", "S. V.", "" ] ]
Some aspects of applications of bunching parameters are discussed. It is investigated to what extent Monte-Carlo models, which have been tuned to reproduce global event-shape variables and single-particle inclusive distributions, agree with each other.
2308.10942
Xiaohui Liu
Xiao Lin Li, Xiaohui Liu, Feng Yuan and Hua Xing Zhu
Illuminating Nucleon Gluon Interference via Calorimetric Asymmetry
6 pages, 5 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We present an innovative approach to the linearly polarized gluons confined inside the unpolarized nucleon in lepton-nucleon scattering. Our method analyzes the correlation of energy flows at azimuthal separations $\phi$. The interference of the spinning gluon with both positive and negative helicities translates into a $\cos(2\phi)$ asymmetry imprinted on the detector. Unlike the conventional transverse momentum dependent (TMD) probes, the $\cos(2\phi)$ asymmetry in this approach is preserved by rotational symmetry, holds to all orders, and is free of radiation contamination, thus expected to provide the exquisite signature of the nucleon linearly polarized gluons.
[ { "created": "Mon, 21 Aug 2023 18:00:02 GMT", "version": "v1" } ]
2023-08-23
[ [ "Li", "Xiao Lin", "" ], [ "Liu", "Xiaohui", "" ], [ "Yuan", "Feng", "" ], [ "Zhu", "Hua Xing", "" ] ]
We present an innovative approach to the linearly polarized gluons confined inside the unpolarized nucleon in lepton-nucleon scattering. Our method analyzes the correlation of energy flows at azimuthal separations $\phi$. The interference of the spinning gluon with both positive and negative helicities translates into a $\cos(2\phi)$ asymmetry imprinted on the detector. Unlike the conventional transverse momentum dependent (TMD) probes, the $\cos(2\phi)$ asymmetry in this approach is preserved by rotational symmetry, holds to all orders, and is free of radiation contamination, thus expected to provide the exquisite signature of the nucleon linearly polarized gluons.
hep-ph/0204136
Shaaban Khalil
G.C. Branco, M.E. Gomez, S. Khalil and A.M. Teixeira
Supersymmetry and a rationale for small CP violating phases
30 pages, 5 figures. Version to appear in Nucl. Phys. B
Nucl.Phys.B659:119,2003
10.1016/S0550-3213(03)00230-X
FISIST/14-2001/CFIF, IPPP/01/58, DCPT/01/114
hep-ph
null
We analyse the CP problem in the context of a supersymmetric extension of the standard model with universal strength of Yukawa couplings. A salient feature of these models is that the CP phases are constrained to be very small by the hierarchy of the quark masses, and the pattern of CKM mixing angles. This leads to a small amount of CP violation from the usual KM mechanism and a significant contribution from supersymmetry is required. Due to the large generation mixing in some of the supersymmetric interactions, the electric dipole moments impose severe constraints on the parameter space, forcing the trilinear couplings to be factorizable in matrix form. We find that the LL mass insertions give the dominant gluino contribution to saturate epsilon_K. The chargino contributions to epsilon'/epsilon are significant and can accommodate the experimental results. In this framework, the standard model gives a negligible contribution to the CP asymmetry in B-meson decay, a_{J/\psi K_s}. However, due to supersymmetric contributions to B_d-\bar{B}_d mixing, the recent large value of a_{J/\psi K_s} can be accommodated.
[ { "created": "Fri, 12 Apr 2002 11:26:43 GMT", "version": "v1" }, { "created": "Sat, 13 Apr 2002 08:43:50 GMT", "version": "v2" }, { "created": "Thu, 10 Apr 2003 22:12:20 GMT", "version": "v3" } ]
2009-09-25
[ [ "Branco", "G. C.", "" ], [ "Gomez", "M. E.", "" ], [ "Khalil", "S.", "" ], [ "Teixeira", "A. M.", "" ] ]
We analyse the CP problem in the context of a supersymmetric extension of the standard model with universal strength of Yukawa couplings. A salient feature of these models is that the CP phases are constrained to be very small by the hierarchy of the quark masses, and the pattern of CKM mixing angles. This leads to a small amount of CP violation from the usual KM mechanism and a significant contribution from supersymmetry is required. Due to the large generation mixing in some of the supersymmetric interactions, the electric dipole moments impose severe constraints on the parameter space, forcing the trilinear couplings to be factorizable in matrix form. We find that the LL mass insertions give the dominant gluino contribution to saturate epsilon_K. The chargino contributions to epsilon'/epsilon are significant and can accommodate the experimental results. In this framework, the standard model gives a negligible contribution to the CP asymmetry in B-meson decay, a_{J/\psi K_s}. However, due to supersymmetric contributions to B_d-\bar{B}_d mixing, the recent large value of a_{J/\psi K_s} can be accommodated.
1610.03849
Asher Berlin
Asher Berlin, Dan Hooper
Axion-Assisted Production of Sterile Neutrino Dark Matter
5 pages, 3 figures
Phys. Rev. D 95, 075017 (2017)
10.1103/PhysRevD.95.075017
FERMILAB-PUB-16-423-A, SLAC-PUB-16838
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sterile neutrinos can be generated in the early universe through oscillations with active neutrinos and represent a popular and well-studied candidate for our universe's dark matter. Stringent constraints from X-ray and gamma-ray line searches, however, have excluded the simplest of such models. In this letter, we propose a novel alternative to the standard scenario in which the mixing angle between the sterile and active neutrinos is a dynamical quantity, induced through interactions with a light axion-like field. As the energy density of the axion-like particles is diluted by Hubble expansion, the degree of mixing is reduced at late times, suppressing the decay rate and easily alleviating any tension with X-ray or gamma-ray constraints. We present a simple model which illustrates the phenomenology of this scenario, and also describe a framework in which the QCD axion is responsible for the production of sterile neutrinos in the early universe.
[ { "created": "Wed, 12 Oct 2016 20:00:00 GMT", "version": "v1" } ]
2017-04-19
[ [ "Berlin", "Asher", "" ], [ "Hooper", "Dan", "" ] ]
Sterile neutrinos can be generated in the early universe through oscillations with active neutrinos and represent a popular and well-studied candidate for our universe's dark matter. Stringent constraints from X-ray and gamma-ray line searches, however, have excluded the simplest of such models. In this letter, we propose a novel alternative to the standard scenario in which the mixing angle between the sterile and active neutrinos is a dynamical quantity, induced through interactions with a light axion-like field. As the energy density of the axion-like particles is diluted by Hubble expansion, the degree of mixing is reduced at late times, suppressing the decay rate and easily alleviating any tension with X-ray or gamma-ray constraints. We present a simple model which illustrates the phenomenology of this scenario, and also describe a framework in which the QCD axion is responsible for the production of sterile neutrinos in the early universe.
hep-ph/9610225
Luciano Rezzolla
L. Rezzolla (SISSA and Dept. of Physics, Univ. of Illinois at Urbana-Champaign)
Baryon number segregation at the end of the cosmological quark-hadron transition
33 pages, Latex file, 6 postscript figures included in the text (psfig.tex). To appear in Phys. Rev. D15
Phys.Rev. D54 (1996) 6072-6082
10.1103/PhysRevD.54.6072
SISSA 144/96/A
hep-ph astro-ph
null
One of the most interesting questions regarding a possible first order cosmological quark--hadron phase transition concerns the final fate of the baryon number contained within the disconnected quark regions at the end of the transition. We here present a detailed investigation of the hydrodynamical evolution of an evaporating quark drop, using a multi-component fluid description to follow the mechanisms of baryon number segregation. With this approach, we are able to take account of the simultaneous effects of baryon number flux suppression at the phase interface, entropy extraction by means of particles having long mean-free-paths, and baryon number diffusion. A range of computations has been performed to investigate the permitted parameter-space and this has shown that significant baryon number concentrations, perhaps even up to densities above that of nuclear matter, represent an inevitable outcome within this scenario.
[ { "created": "Wed, 2 Oct 1996 22:15:22 GMT", "version": "v1" } ]
2009-10-28
[ [ "Rezzolla", "L.", "", "SISSA and Dept. of Physics, Univ. of Illinois at\n Urbana-Champaign" ] ]
One of the most interesting questions regarding a possible first order cosmological quark--hadron phase transition concerns the final fate of the baryon number contained within the disconnected quark regions at the end of the transition. We here present a detailed investigation of the hydrodynamical evolution of an evaporating quark drop, using a multi-component fluid description to follow the mechanisms of baryon number segregation. With this approach, we are able to take account of the simultaneous effects of baryon number flux suppression at the phase interface, entropy extraction by means of particles having long mean-free-paths, and baryon number diffusion. A range of computations has been performed to investigate the permitted parameter-space and this has shown that significant baryon number concentrations, perhaps even up to densities above that of nuclear matter, represent an inevitable outcome within this scenario.
1611.05060
Farvah Mahmoudi
F. Mahmoudi, T. Hurth, S. Neshatpour
Present Status of b -> s l+ l- Anomalies
6 pages, 6 figures. Contribution to the proceedings of the Sixth Workshop on Theory, Phenomenology and Experiments in Flavour Physics - Capri, June 2016
null
null
CERN-TH-2016-231, IPM/PA-450, MITP/16-113
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the observed deviations in b -> s l+ l- processes from the Standard Model predictions and present global fits for the New Physics description of these anomalies. We further investigate the stability of the global fits under different theoretical assumptions and suggest strategies and a number of observables to clear up the source of the anomalies.
[ { "created": "Tue, 15 Nov 2016 21:19:09 GMT", "version": "v1" } ]
2016-11-17
[ [ "Mahmoudi", "F.", "" ], [ "Hurth", "T.", "" ], [ "Neshatpour", "S.", "" ] ]
We discuss the observed deviations in b -> s l+ l- processes from the Standard Model predictions and present global fits for the New Physics description of these anomalies. We further investigate the stability of the global fits under different theoretical assumptions and suggest strategies and a number of observables to clear up the source of the anomalies.