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0709.3494
Jernej Kamenik
Jernej F. Kamenik
Role of Resonances in Heavy Meson Processes within Standard Model and Beyond
184 pages, Ph.D. Thesis (Advisor: Svjetlana Fajfer)
null
null
null
hep-ph
null
The effective theory based on combined chiral and heavy quark symmetry, the heavy meson chiral perturbation theory, is applied to studying the role of resonances in various processes of heavy mesons within and beyond the Standard Model. Chiral corrections including both positive and negative parity heavy meson doublets are calculated to the effective strong couplings featuring in the effective theory leading order interaction Lagrangian, to the Isgur-Wise functions in semileptonic B to D decays and to the complete set of supersymmetric four-quark operators mediating heavy neutral meson mixing. Bare values of the effective strong couplings are extracted from the measured decay widths of charmed resonances. Chiral behavior of the couplings, Isgur-Wise functions and heavy meson bag parameters is studied in the leading logarithmic approximation. In semileptonic heavy to light decays we determine resonance contributions to the various form factors within an effective theory inspired model at zero recoil. We employ a form factor parameterization based on effective theory limits to extrapolate our results to the whole kinematical region in charm decays. We compare our results with experimental data and lattice calculations. Very rare nonleptonic decays of the B_c meson are studied within the Standard Model where they are mediated by box loop diagrams, and within a number of Standard Model extensions. Based on existing experimental searches for related B meson decays, limits are imposed on some of the models studied. The most promissing nonleptonic two- and three-body decay channels of the B_c meson in the search for such new physics contributions are identified.
[ { "created": "Fri, 21 Sep 2007 18:24:00 GMT", "version": "v1" }, { "created": "Tue, 6 Nov 2007 13:55:18 GMT", "version": "v2" } ]
2007-11-06
[ [ "Kamenik", "Jernej F.", "" ] ]
The effective theory based on combined chiral and heavy quark symmetry, the heavy meson chiral perturbation theory, is applied to studying the role of resonances in various processes of heavy mesons within and beyond the Standard Model. Chiral corrections including both positive and negative parity heavy meson doublets are calculated to the effective strong couplings featuring in the effective theory leading order interaction Lagrangian, to the Isgur-Wise functions in semileptonic B to D decays and to the complete set of supersymmetric four-quark operators mediating heavy neutral meson mixing. Bare values of the effective strong couplings are extracted from the measured decay widths of charmed resonances. Chiral behavior of the couplings, Isgur-Wise functions and heavy meson bag parameters is studied in the leading logarithmic approximation. In semileptonic heavy to light decays we determine resonance contributions to the various form factors within an effective theory inspired model at zero recoil. We employ a form factor parameterization based on effective theory limits to extrapolate our results to the whole kinematical region in charm decays. We compare our results with experimental data and lattice calculations. Very rare nonleptonic decays of the B_c meson are studied within the Standard Model where they are mediated by box loop diagrams, and within a number of Standard Model extensions. Based on existing experimental searches for related B meson decays, limits are imposed on some of the models studied. The most promissing nonleptonic two- and three-body decay channels of the B_c meson in the search for such new physics contributions are identified.
0804.2185
Won Sang Cho
Won Sang Cho, Kiwoon Choi, Yeong Gyun Kim, Chan Beom Park
Measuring the top quark mass with m_T2 at the LHC
10 pages, 4 figures
Phys.Rev.D78:034019,2008
10.1103/PhysRevD.78.034019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility to measure the top quark mass using the collider variable $m_{T2}$ at the LHC experiment. Monte Carlo studies of $m_{T2}$ are performed with the events corresponding to the dilepton decays of $t\bar{t}$ produced at the LHC with 10 $fb^{-1}$ integrated luminosity. Our analysis suggests that the top quark mass can be determined by the $m_{T2}$ variable alone with a good precision at the level of 1 GeV.
[ { "created": "Mon, 14 Apr 2008 14:22:18 GMT", "version": "v1" } ]
2008-11-26
[ [ "Cho", "Won Sang", "" ], [ "Choi", "Kiwoon", "" ], [ "Kim", "Yeong Gyun", "" ], [ "Park", "Chan Beom", "" ] ]
We investigate the possibility to measure the top quark mass using the collider variable $m_{T2}$ at the LHC experiment. Monte Carlo studies of $m_{T2}$ are performed with the events corresponding to the dilepton decays of $t\bar{t}$ produced at the LHC with 10 $fb^{-1}$ integrated luminosity. Our analysis suggests that the top quark mass can be determined by the $m_{T2}$ variable alone with a good precision at the level of 1 GeV.
1404.0109
Yikun Wang
Yikun Wang, Zhi-zhong Xing
Commutators of lepton mass matrices associated with seesaw and leptogenesis
LaTex 8 pages. Minor changes. Accepted for publication in Phys. Rev. D
Phys. Rev. D 89, 097301 (2014)
10.1103/PhysRevD.89.097301
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The origin of tiny neutrino masses and the baryon number asymmetry of the Universe are naturally interpreted by the canonical seesaw and leptogenesis mechanisms, in which there are the heavy Majorana neutrino mass matrix $M_{\rm R}$, the Dirac neutrino mass matrix $M_{\rm D}$, the charged-lepton mass matrix $M_\ell$ and the effective (light) neutrino mass matrix $M_\nu$. We find that ${\rm Im}\left(\det\left[ M^\dagger_{\rm D} M_{\rm D}, M^\dagger_{\rm R} M_{\rm R} \right]\right)$, ${\rm Im}\left(\det\left[ M_\ell M^\dagger_\ell, M_\nu M^\dagger_\nu \right]\right)$ and ${\rm Im}\left(\det\left[ M_\ell M^\dagger_\ell, M_{\rm D} M^\dagger_{\rm D} \right]\right)$ can serve for a basis-independent measure of CP violation associated with lepton-number-violating decays of heavy neutrinos, flavor oscillations of light neutrinos and lepton-flavor-violating decays of charged leptons, respectively. We first calculate these quantities with the help of a standard parametrization of the $6\times 6$ flavor mixing matrix, and then discuss their implications on both leptogenesis and CP violation at low energy scales. A comparison with the weak-basis invariants of leptogenesis as proposed by Branco {\it et al} is also made.
[ { "created": "Tue, 1 Apr 2014 02:23:10 GMT", "version": "v1" }, { "created": "Sun, 25 May 2014 09:39:18 GMT", "version": "v2" } ]
2014-06-06
[ [ "Wang", "Yikun", "" ], [ "Xing", "Zhi-zhong", "" ] ]
The origin of tiny neutrino masses and the baryon number asymmetry of the Universe are naturally interpreted by the canonical seesaw and leptogenesis mechanisms, in which there are the heavy Majorana neutrino mass matrix $M_{\rm R}$, the Dirac neutrino mass matrix $M_{\rm D}$, the charged-lepton mass matrix $M_\ell$ and the effective (light) neutrino mass matrix $M_\nu$. We find that ${\rm Im}\left(\det\left[ M^\dagger_{\rm D} M_{\rm D}, M^\dagger_{\rm R} M_{\rm R} \right]\right)$, ${\rm Im}\left(\det\left[ M_\ell M^\dagger_\ell, M_\nu M^\dagger_\nu \right]\right)$ and ${\rm Im}\left(\det\left[ M_\ell M^\dagger_\ell, M_{\rm D} M^\dagger_{\rm D} \right]\right)$ can serve for a basis-independent measure of CP violation associated with lepton-number-violating decays of heavy neutrinos, flavor oscillations of light neutrinos and lepton-flavor-violating decays of charged leptons, respectively. We first calculate these quantities with the help of a standard parametrization of the $6\times 6$ flavor mixing matrix, and then discuss their implications on both leptogenesis and CP violation at low energy scales. A comparison with the weak-basis invariants of leptogenesis as proposed by Branco {\it et al} is also made.
1001.3509
Honghui Wang
Bo Feng, Honghui Wang
Cross Section Evaluation by Spinor Integration II: The massive case in 4D
23 pages, 1 figure;further comments and references added
Phys.Rev.D81:056007,2010
10.1103/PhysRevD.81.056007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we continue our study of calculating the cross section by the spinor method, i.e., performing the phase space integration using the spinor method. We have focused on the case where the physical momenta are massive and in pure 4D. We established the framework of such a new method and presented several examples, including two real progresses: $Z^0\to l^+ l^- H$ and $\bar{qq} \to \bar{ff} H^0$.
[ { "created": "Wed, 20 Jan 2010 08:49:46 GMT", "version": "v1" }, { "created": "Tue, 16 Mar 2010 08:52:30 GMT", "version": "v2" } ]
2014-11-20
[ [ "Feng", "Bo", "" ], [ "Wang", "Honghui", "" ] ]
In this paper, we continue our study of calculating the cross section by the spinor method, i.e., performing the phase space integration using the spinor method. We have focused on the case where the physical momenta are massive and in pure 4D. We established the framework of such a new method and presented several examples, including two real progresses: $Z^0\to l^+ l^- H$ and $\bar{qq} \to \bar{ff} H^0$.
2404.15085
Nakul Soni Dr.
Mikhail A. Ivanov, Jignesh N. Pandya, Pietro Santorelli, Nakul R. Soni
Decay $B_c^+ \to D_{(s)}^{(*)+} \ell^+\ell^-$ within covariant confined quark model
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Here we study the rare decay of $B_c$ mesons within the effective field theoretical framework of covariant confined quark model. The transition form factors corresponding to $B_c^+ \to D^{(*)+}$ and $B_c^+ \to D_s^{(*)+}$ are computed in the entire $q^2$ range. Using form factors we compute the branching fractions and compare with the available theoretical approaches. We also compute other physical observables such as forward backward asymmetry, longitudinal and transverse polarizations and various clean angular observables.
[ { "created": "Tue, 23 Apr 2024 14:36:38 GMT", "version": "v1" } ]
2024-04-24
[ [ "Ivanov", "Mikhail A.", "" ], [ "Pandya", "Jignesh N.", "" ], [ "Santorelli", "Pietro", "" ], [ "Soni", "Nakul R.", "" ] ]
Here we study the rare decay of $B_c$ mesons within the effective field theoretical framework of covariant confined quark model. The transition form factors corresponding to $B_c^+ \to D^{(*)+}$ and $B_c^+ \to D_s^{(*)+}$ are computed in the entire $q^2$ range. Using form factors we compute the branching fractions and compare with the available theoretical approaches. We also compute other physical observables such as forward backward asymmetry, longitudinal and transverse polarizations and various clean angular observables.
2304.12128
Chang Yang
Hang Liu and Chang Yang
Two-body hadronic decays of Xi^{0}_c in light front approach
10 pages,4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study, we investigate the nonleptonic decays of the charmed-baryon Xi^ {0} _ c induced by the c -> u(d\bar{d})/(s\bar{s}) transition. Utilizing the factorization assumption, we decompose the decay amplitudes in terms of transition form factors which are then calculated within the light-front quark model. We employ helicity amplitudes to analyze the nonleptonic decay modes of the charmed-baryon Xi^ {0} _c and derive benchmark results for decay widths and branching fractions. Our calculations suggest that the branching fractions for some of these rare nonleptonic decays are at the order of 10^ {-4} - 10^ {-3}, which are likely to be detectable at experiments such as LHCb or BESIII. The potential data accumulated in the future may help to further our understanding of the decay mechanism in the presence of charm quarks.
[ { "created": "Mon, 24 Apr 2023 14:32:40 GMT", "version": "v1" }, { "created": "Mon, 14 Aug 2023 11:16:31 GMT", "version": "v2" } ]
2023-08-15
[ [ "Liu", "Hang", "" ], [ "Yang", "Chang", "" ] ]
In this study, we investigate the nonleptonic decays of the charmed-baryon Xi^ {0} _ c induced by the c -> u(d\bar{d})/(s\bar{s}) transition. Utilizing the factorization assumption, we decompose the decay amplitudes in terms of transition form factors which are then calculated within the light-front quark model. We employ helicity amplitudes to analyze the nonleptonic decay modes of the charmed-baryon Xi^ {0} _c and derive benchmark results for decay widths and branching fractions. Our calculations suggest that the branching fractions for some of these rare nonleptonic decays are at the order of 10^ {-4} - 10^ {-3}, which are likely to be detectable at experiments such as LHCb or BESIII. The potential data accumulated in the future may help to further our understanding of the decay mechanism in the presence of charm quarks.
hep-ph/9308375
Ed Stoeffhaas
F.Halzen
14th International Workshop on Weak Interactions: Concluding Remarks
Talk presented at the 14th International Workshop on Weak Interactions and Neutrinos, Seoul, Korea, July 1993. Standard Latex. 8 pages including 2 postscript figures, "uufiles" and submitted to hep-ph. Uses epsf.sty to include figures in text. MAD/PH/786
null
null
null
hep-ph
null
This superbly organized workshop invited the participants to focus on four outstanding questions in weak interactions: i) is the electroweak model correct at the quantum level? ii)supersymmetry? iii) neutrino mass? iv) what is the nature of CP-violation? The meeting demonstrated how weak-interaction physics has become a terrain successfully covered by accelerator and non-accelerator experiments in a very complimentary way.
[ { "created": "Tue, 31 Aug 1993 21:30:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Halzen", "F.", "" ] ]
This superbly organized workshop invited the participants to focus on four outstanding questions in weak interactions: i) is the electroweak model correct at the quantum level? ii)supersymmetry? iii) neutrino mass? iv) what is the nature of CP-violation? The meeting demonstrated how weak-interaction physics has become a terrain successfully covered by accelerator and non-accelerator experiments in a very complimentary way.
hep-ph/9607323
null
Christopher D. Carone (LBNL)
(S_3)^3 Theories of Flavor
12 pp. LaTeX, Talk presented at the 5th International Workshop on Supersymmetry and Unification of Fundamental Interactions (SUSY-96), U. of Maryland, College Park, May 29-June 1, 1996
Nucl.Phys.Proc.Suppl.52A:177-181,1997
10.1016/S0920-5632(96)00557-9
LBNL-39096
hep-ph
null
I present a supersymmetric theory of flavor based on the discrete flavor group $(S_3)^3$. The model can account for the masses and mixing angles of the standard model, while maintaining sufficient sfermion degeneracy to evade the supersymmetric flavor problem. I demonstrate that the model has a viable phenomenology and makes one very striking prediction: the nucleon decays predominantly to $K l$ where $l$ is a {\em first} generation lepton. I show that the modes $n \rightarrow K^0 \bar{\nu}_e$, $p\rightarrow K^+ \bar{\nu}_e$, and $p\rightarrow K^0 e^+$ occur at comparable rates, and could well be discovered simultaneously at the SuperKamiokande experiment.
[ { "created": "Mon, 15 Jul 1996 20:46:00 GMT", "version": "v1" } ]
2014-11-17
[ [ "Carone", "Christopher D.", "", "LBNL" ] ]
I present a supersymmetric theory of flavor based on the discrete flavor group $(S_3)^3$. The model can account for the masses and mixing angles of the standard model, while maintaining sufficient sfermion degeneracy to evade the supersymmetric flavor problem. I demonstrate that the model has a viable phenomenology and makes one very striking prediction: the nucleon decays predominantly to $K l$ where $l$ is a {\em first} generation lepton. I show that the modes $n \rightarrow K^0 \bar{\nu}_e$, $p\rightarrow K^+ \bar{\nu}_e$, and $p\rightarrow K^0 e^+$ occur at comparable rates, and could well be discovered simultaneously at the SuperKamiokande experiment.
hep-ph/0004091
Karim Benakli
I. Antoniadis, K. Benakli, M. Quiros
Radiative Symmetry Breaking in Brane Models
16 pages, Latex2e, 2 eps figures. Some comments on the large (longitudinal) radius limit of the mass term at the origin are developed, and new references added
Nucl.Phys. B583 (2000) 35-48
10.1016/S0550-3213(00)00357-6
null
hep-ph hep-th
null
We propose a way to generate the electroweak symmetry breaking radiatively in non-supersymmetric type I models with string scale in the TeV region. By identifying the Higgs field with a tree-level massless open string state, we find that a negative squared mass term can be generated at one loop. It is finite, computable and typically a loop factor smaller than the string scale, that acts as an ultraviolet cutoff in the effective field theory. When the Higgs open string has both ends confined on our world brane, its mass is predicted to be around 120 GeV, i.e. that of the lightest Higgs in the minimal supersymmetric model for large $\tan\beta$ and $m_A$. Moreover, the string scale turns out to be one to two orders of magnitude higher than the weak scale. We also discuss possible effects of higher order string threshold corrections that might increase the string scale and the Higgs mass.
[ { "created": "Mon, 10 Apr 2000 16:38:16 GMT", "version": "v1" }, { "created": "Thu, 4 May 2000 15:08:22 GMT", "version": "v2" } ]
2009-10-31
[ [ "Antoniadis", "I.", "" ], [ "Benakli", "K.", "" ], [ "Quiros", "M.", "" ] ]
We propose a way to generate the electroweak symmetry breaking radiatively in non-supersymmetric type I models with string scale in the TeV region. By identifying the Higgs field with a tree-level massless open string state, we find that a negative squared mass term can be generated at one loop. It is finite, computable and typically a loop factor smaller than the string scale, that acts as an ultraviolet cutoff in the effective field theory. When the Higgs open string has both ends confined on our world brane, its mass is predicted to be around 120 GeV, i.e. that of the lightest Higgs in the minimal supersymmetric model for large $\tan\beta$ and $m_A$. Moreover, the string scale turns out to be one to two orders of magnitude higher than the weak scale. We also discuss possible effects of higher order string threshold corrections that might increase the string scale and the Higgs mass.
1909.07790
Himadri Roy
Indrani Chakraborty, Himadri Roy
Type-I thermal leptogenesis in $Z_3$-symmetric three Higgs doublet model
37 pages, 10 captioned figures, 1 table, Accepted for publication in EPJC
null
10.1140/epjc/s10052-020-8377-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Our present work explores the possibility of neutrino mass generation through {\em Type-I see-saw} mechanism and provides an explanation of the baryon asymmetry of the Universe via thermal leptogenesis in the framework of $Z_3$-symmetric three Higgs doublet model (3HDM) augmented with three right-handed neutrinos. Here the thermal leptogenesis is initiated by the out-of-equilibrium decay of the lightest heavy neutrino $N_1$. The constraints arising out of the scalar sector put strong bound on the model parameter $\tan \beta$, which in turn takes part in the computation of the lepton asymmetry $\epsilon$. Lepton asymmetry being converted partially into the baryon asymmetry by electroweak sphelaron processes, will account for the required baryon asymmetry satisfying the current data. We therefore analyse the parameter space consistent with the constraints arising from neutrino oscillation, lepton asymmetry and baryon asymmetry together, last one being the most stringent one.
[ { "created": "Tue, 17 Sep 2019 13:41:42 GMT", "version": "v1" }, { "created": "Mon, 7 Sep 2020 14:00:45 GMT", "version": "v2" } ]
2020-09-08
[ [ "Chakraborty", "Indrani", "" ], [ "Roy", "Himadri", "" ] ]
Our present work explores the possibility of neutrino mass generation through {\em Type-I see-saw} mechanism and provides an explanation of the baryon asymmetry of the Universe via thermal leptogenesis in the framework of $Z_3$-symmetric three Higgs doublet model (3HDM) augmented with three right-handed neutrinos. Here the thermal leptogenesis is initiated by the out-of-equilibrium decay of the lightest heavy neutrino $N_1$. The constraints arising out of the scalar sector put strong bound on the model parameter $\tan \beta$, which in turn takes part in the computation of the lepton asymmetry $\epsilon$. Lepton asymmetry being converted partially into the baryon asymmetry by electroweak sphelaron processes, will account for the required baryon asymmetry satisfying the current data. We therefore analyse the parameter space consistent with the constraints arising from neutrino oscillation, lepton asymmetry and baryon asymmetry together, last one being the most stringent one.
0810.5401
Jihn E. Kim
Jihn E. Kim
Dark Matter Related to Axion and Axino
9 pages. Talk presented at IDM08
PoS idm2008:066,2008
null
null
hep-ph astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I discuss the essential features of the QCD axion: the strong CP solution and hence its theoretical necessity. I also review the axion and axino effects on astrophysics and cosmology, in particular with emphasis on their role in the dark matter component in the universe.
[ { "created": "Thu, 30 Oct 2008 02:07:00 GMT", "version": "v1" } ]
2010-02-17
[ [ "Kim", "Jihn E.", "" ] ]
I discuss the essential features of the QCD axion: the strong CP solution and hence its theoretical necessity. I also review the axion and axino effects on astrophysics and cosmology, in particular with emphasis on their role in the dark matter component in the universe.
hep-ph/0307169
Shin'ichiro Ando
Shin'ichiro Ando
Decaying neutrinos and implications from the supernova relic neutrino observation
15 pages, 2 figures, corrected typos, added references. Final version to appear in Physics Letters B
Phys.Lett. B570 (2003) 11
10.1016/j.physletb.2003.07.009
UTAP-453
hep-ph astro-ph
null
We propose that supernova relic neutrino (SRN) observation can be used to set constraints on the neutrino decay models. Because of the long distance scale from cosmological supernovae to the Earth, SRN have possibility to provide much stronger limit than the present one obtained from solar neutrino observation. Since the currently available data are only the upper limit on the flux integrated over $E_{\bar\nu_e}>19.3$ MeV, the decay models on which we can set constraints is quite restricted; they must satisfy specific conditions such that the daughter neutrinos are active species, the neutrino mass spectrum is quasi-degenerate, and the neutrino mass hierarchy is normal. Our numerical calculation clearly indicates that the neutrino decay model with $(\tau_2/m,\tau_3/m)\alt (10^{10},10^{10})$ [s/eV], where $\tau_i$ represents the lifetime of mass eigenstates $\bar\nu_i$, appears to give the SRN flux that is larger than the current upper limit. However, since the theoretical SRN prediction contains many uncertainties concerning a supernova rate in the universe or simulation of supernova explosions, we cannot conclude that there exists the excluded parameter region of the neutrino lifetime. In the near future, further reduced upper limit is actually expected, and it will provide more severe constraints on the neutrino decay models.
[ { "created": "Sun, 13 Jul 2003 08:25:16 GMT", "version": "v1" }, { "created": "Thu, 7 Aug 2003 12:04:22 GMT", "version": "v2" } ]
2009-11-10
[ [ "Ando", "Shin'ichiro", "" ] ]
We propose that supernova relic neutrino (SRN) observation can be used to set constraints on the neutrino decay models. Because of the long distance scale from cosmological supernovae to the Earth, SRN have possibility to provide much stronger limit than the present one obtained from solar neutrino observation. Since the currently available data are only the upper limit on the flux integrated over $E_{\bar\nu_e}>19.3$ MeV, the decay models on which we can set constraints is quite restricted; they must satisfy specific conditions such that the daughter neutrinos are active species, the neutrino mass spectrum is quasi-degenerate, and the neutrino mass hierarchy is normal. Our numerical calculation clearly indicates that the neutrino decay model with $(\tau_2/m,\tau_3/m)\alt (10^{10},10^{10})$ [s/eV], where $\tau_i$ represents the lifetime of mass eigenstates $\bar\nu_i$, appears to give the SRN flux that is larger than the current upper limit. However, since the theoretical SRN prediction contains many uncertainties concerning a supernova rate in the universe or simulation of supernova explosions, we cannot conclude that there exists the excluded parameter region of the neutrino lifetime. In the near future, further reduced upper limit is actually expected, and it will provide more severe constraints on the neutrino decay models.
hep-ph/0502009
Shmatov Sergei
I.Golutvin, E.Rogalev, M.Savina, S.Shmatov
Search for new heavy resonances at the LHC
7 pages, 6 figures, The talk given at the XVIIIth International Workshop "High Energy Physics and Quantum Field Theory", 17-23 June 2004, St. Petersburg, Russia
null
null
null
hep-ph
null
In this article we carry out an analysis of LHC potential to search for new dimuon resonance states from extended gauge models and the Randall-Sundrum scenario of TeV-scale gravity.
[ { "created": "Tue, 1 Feb 2005 16:04:54 GMT", "version": "v1" }, { "created": "Wed, 2 Feb 2005 07:49:22 GMT", "version": "v2" }, { "created": "Sat, 12 Feb 2005 11:58:06 GMT", "version": "v3" } ]
2007-05-23
[ [ "Golutvin", "I.", "" ], [ "Rogalev", "E.", "" ], [ "Savina", "M.", "" ], [ "Shmatov", "S.", "" ] ]
In this article we carry out an analysis of LHC potential to search for new dimuon resonance states from extended gauge models and the Randall-Sundrum scenario of TeV-scale gravity.
1810.06958
Wolfgang Lucha
Wolfgang Lucha
Bethe-Salpeter-Motivated Modelling of Pseudo-Goldstone Pseudoscalar Mesons
8 pages, 3 figures, contributed to "XIII Quark Confinement and the Hadron Spectrum - Confinement2018" (31 July - 6 August 2018, Maynooth University, Ireland)
PoS Confinement2018 (2019) 251
null
HEPHY-PUB 1007/18 (2018)
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply a description of bound states of fermion and antifermion by means of our approximation to the Bethe-Salpeter formalism that retains part of the information on relativistic effects provided by the full fermion propagator to the lightest pseudoscalar mesons. Therein, the pseudo-Goldstone nature of the latter quark-antiquark bound states is taken into account by appropriately formulated effective interactions. Scrutinizing the predictions of this bound-state approach for meson masses, decay constants and in-meson condensates by relying on a generalized Gell-Mann-Oakes-Renner relation shows that the light-quark-mass values required for agreement are all in the right ballpark.
[ { "created": "Tue, 16 Oct 2018 12:46:45 GMT", "version": "v1" } ]
2019-06-20
[ [ "Lucha", "Wolfgang", "" ] ]
We apply a description of bound states of fermion and antifermion by means of our approximation to the Bethe-Salpeter formalism that retains part of the information on relativistic effects provided by the full fermion propagator to the lightest pseudoscalar mesons. Therein, the pseudo-Goldstone nature of the latter quark-antiquark bound states is taken into account by appropriately formulated effective interactions. Scrutinizing the predictions of this bound-state approach for meson masses, decay constants and in-meson condensates by relying on a generalized Gell-Mann-Oakes-Renner relation shows that the light-quark-mass values required for agreement are all in the right ballpark.
hep-ph/0002266
Andrey Grozin
A.G.Grozin
Calculating three-loop diagrams in Heavy Quark Effective Theory with integration-by-parts recurrence relations
LaTeX2e (JHEP documentclass), 33 pages, 13 eps figures included. The complete paper is also available via the www at http://www-ttp.physik.uni-karlsruhe.de/Preprints/ V2: bug fixes in formulas, improvements of the algorithm, some restructuring. REDUCE package Grinder is available at http://www-ttp.physik.uni-karlsruhe.de/Progdata/ttp00/ttp00-01/
JHEP 0003:013,2000
10.1088/1126-6708/2000/03/013
TTP00-01
hep-ph
null
An algorithm for calculation of three-loop propagator diagrams in HQET, based on integration-by-parts recurrence relations, is constructed and implemented as a REDUCE package Grinder, and in Axiom.
[ { "created": "Fri, 25 Feb 2000 12:37:31 GMT", "version": "v1" }, { "created": "Mon, 14 Aug 2000 13:53:36 GMT", "version": "v2" } ]
2011-04-20
[ [ "Grozin", "A. G.", "" ] ]
An algorithm for calculation of three-loop propagator diagrams in HQET, based on integration-by-parts recurrence relations, is constructed and implemented as a REDUCE package Grinder, and in Axiom.
hep-ph/0611271
Zhi-Gang Wang
Z. G. Wang (NCEPU, Baoding)
Structure of the axial-vector meson $D_{s1}(2460)$ and the strong coupling constant $g_{D_{s1} D^* K}$ with the light-cone QCD sum rules
17 pages, 7 figures, revised version. In the first version, I take the value $f_{D_{s1}}= (0.25\pm0.02)GeV$ in numerical calculation, in the revised version, I take a small value $f_{D_{s1}}=(0.225 \pm0.020)GeV$, the value of the strong coupling constant is also changed
J.Phys.G34:753-765,2007
10.1088/0954-3899/34/4/011
null
hep-ph
null
In this article, we take the point of view that the charmed axial-vector meson $D_{s1}(2460)$ is the conventional $c\bar{s}$ meson and calculate the strong coupling constant $g_{D_{s1} D^* K}$ in the framework of the light-cone QCD sum rules approach. The numerical values of strong coupling constants $g_{D_{s1} D^* K}$ and $g_{D_{s0} D K}$ are very large, and support the hadronic dressing mechanism. Just like the scalar mesons $f_0(980)$ and $a_0(980)$, the scalar meson $D_{s0}(2317)$ and axial-vector meson $D_{s1}(2460)$ may have small $c\bar{s}$ kernels of the typical $c\bar{s}$ meson size, the strong couplings to the hadronic channels (or the virtual mesons loops) may result in smaller masses than the conventional $c\bar{s}$ mesons in the constituent quark models, and enrich the pure $c\bar{s}$ states with other components.
[ { "created": "Tue, 21 Nov 2006 15:17:07 GMT", "version": "v1" }, { "created": "Wed, 22 Nov 2006 03:13:47 GMT", "version": "v2" }, { "created": "Sun, 4 Feb 2007 01:57:45 GMT", "version": "v3" } ]
2008-11-26
[ [ "Wang", "Z. G.", "", "NCEPU, Baoding" ] ]
In this article, we take the point of view that the charmed axial-vector meson $D_{s1}(2460)$ is the conventional $c\bar{s}$ meson and calculate the strong coupling constant $g_{D_{s1} D^* K}$ in the framework of the light-cone QCD sum rules approach. The numerical values of strong coupling constants $g_{D_{s1} D^* K}$ and $g_{D_{s0} D K}$ are very large, and support the hadronic dressing mechanism. Just like the scalar mesons $f_0(980)$ and $a_0(980)$, the scalar meson $D_{s0}(2317)$ and axial-vector meson $D_{s1}(2460)$ may have small $c\bar{s}$ kernels of the typical $c\bar{s}$ meson size, the strong couplings to the hadronic channels (or the virtual mesons loops) may result in smaller masses than the conventional $c\bar{s}$ mesons in the constituent quark models, and enrich the pure $c\bar{s}$ states with other components.
1508.01194
Gouranga Nayak
Gouranga C. Nayak
Violation of Factorization Theorem in QCD and QED For Non-Light-Like Wilson Line
51 pages latex. arXiv admin note: substantial text overlap with arXiv:1506.02651, arXiv:1506.02593, arXiv:1506.07146
null
null
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By using path integral formulation of QCD and QED we prove that the factorization theorem is valid for light-like Wilson line but is not valid for non-light-like Wilson line. This conclusion is shown to be consistent with Ward identity and Grammer-Yennie approximation. Hence we find that the factorization theorem is violated in all the previous studies which used the non-light-like Wilson line in the definition of the (transverse momentum dependent) parton distribution function and fragmentation function at high energy colliders.
[ { "created": "Wed, 5 Aug 2015 19:59:11 GMT", "version": "v1" } ]
2015-08-07
[ [ "Nayak", "Gouranga C.", "" ] ]
By using path integral formulation of QCD and QED we prove that the factorization theorem is valid for light-like Wilson line but is not valid for non-light-like Wilson line. This conclusion is shown to be consistent with Ward identity and Grammer-Yennie approximation. Hence we find that the factorization theorem is violated in all the previous studies which used the non-light-like Wilson line in the definition of the (transverse momentum dependent) parton distribution function and fragmentation function at high energy colliders.
0803.2977
Wojciech Krolikowski
Wojciech Krolikowski
A Hidden Valley model of cold dark matter with photonic portal
10 pages, Egs.(30) are added, Abstract is shortened
null
null
IFT-08/5
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the discussed model, the cold dark matter consists of Dirac spin-1/2 fermions, sterile from all Standard Model charges, where masses are generated by a nonzero vacuum expectation value of a field of scalar bosons, also assumed to be sterile. For convenience, these sterile particles have beeen called sterinos and sterons, respectively. It has been conjectured that our sterile world of sterinos and sterons can communicate with the familiar Standard Model world not only through gravity, but also through a photonic portal provided by a very weak effective interaction involving the electromagnetic field F_{\mu \nu} = \partial_\mu A_\nu - \partial_\nu A_\mu coupled to the sterino and steron fields.
[ { "created": "Thu, 20 Mar 2008 12:11:17 GMT", "version": "v1" }, { "created": "Tue, 15 Apr 2008 12:01:56 GMT", "version": "v2" } ]
2008-04-15
[ [ "Krolikowski", "Wojciech", "" ] ]
In the discussed model, the cold dark matter consists of Dirac spin-1/2 fermions, sterile from all Standard Model charges, where masses are generated by a nonzero vacuum expectation value of a field of scalar bosons, also assumed to be sterile. For convenience, these sterile particles have beeen called sterinos and sterons, respectively. It has been conjectured that our sterile world of sterinos and sterons can communicate with the familiar Standard Model world not only through gravity, but also through a photonic portal provided by a very weak effective interaction involving the electromagnetic field F_{\mu \nu} = \partial_\mu A_\nu - \partial_\nu A_\mu coupled to the sterino and steron fields.
2204.03660
Jiang-Hao Yu
Hao-Lin Li, Yu-Han Ni, Ming-Lei Xiao, Jiang-Hao Yu
The Bottom-Up EFT: Complete UV Resonances of the SMEFT Operators
125 pages, 10 figures, 33 tables, revised to match the published version, references added
null
10.1007/JHEP11(2022)170
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The standard model effective field theory (SMEFT) provides systematic parameterization of all possible new physics above the electroweak scale. According to the amplitude-operator correspondence, an effective operator can be decomposed into a linear combination of several j-basis operators, which correspond to local amplitudes carrying certain spin and gauge quantum numbers in a particular scattering channel. Based on the Poincare and gauge symmetries of scattering amplitude, we construct the j-basis using the Casimir method for both the Lorentz and gauge sectors. The quantum numbers of the j-basis operators fix the quantum numbers of any intermediate state in the corresponding amplitudes, such as a UV resonance. This can be re-interpreted as the j-basis/UV correspondence, thus obtaining the j-bases in all partitions of fields for an operator amounts to finding all of its UV origins at tree level, constituting the central part of the bottom-up EFT framework. Applying the j-basis analysis to SMEFT, we obtain a complete list of possible tree-level UV origins of the effective operators at the dimension 5, 6, 7, and all the bosonic operators at the dimension 8.
[ { "created": "Thu, 7 Apr 2022 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 5 Dec 2022 15:59:15 GMT", "version": "v2" } ]
2022-12-21
[ [ "Li", "Hao-Lin", "" ], [ "Ni", "Yu-Han", "" ], [ "Xiao", "Ming-Lei", "" ], [ "Yu", "Jiang-Hao", "" ] ]
The standard model effective field theory (SMEFT) provides systematic parameterization of all possible new physics above the electroweak scale. According to the amplitude-operator correspondence, an effective operator can be decomposed into a linear combination of several j-basis operators, which correspond to local amplitudes carrying certain spin and gauge quantum numbers in a particular scattering channel. Based on the Poincare and gauge symmetries of scattering amplitude, we construct the j-basis using the Casimir method for both the Lorentz and gauge sectors. The quantum numbers of the j-basis operators fix the quantum numbers of any intermediate state in the corresponding amplitudes, such as a UV resonance. This can be re-interpreted as the j-basis/UV correspondence, thus obtaining the j-bases in all partitions of fields for an operator amounts to finding all of its UV origins at tree level, constituting the central part of the bottom-up EFT framework. Applying the j-basis analysis to SMEFT, we obtain a complete list of possible tree-level UV origins of the effective operators at the dimension 5, 6, 7, and all the bosonic operators at the dimension 8.
hep-ph/9910296
Francesco Vissani
Aseshkrishna Datta, Biswarup Mukhopadhyaya and Francesco Vissani
Tevatron Signatures of an R-parity Violating Supersymmetric Theory
10 pages, 4 figures (ps files included). Matches published version
Phys.Lett. B492 (2000) 324-330
10.1016/S0370-2693(00)01104-7
MRI-PHY/P990928, SISSA 115/99/EP
hep-ph hep-ex
null
We show that an R-parity violating supersymmetric scenario which can account for the atmospheric nu(mu) deficit has testable signals at the Fermilab Tevatron with upgraded energy and luminosity. The explanation of neutrino masses and maximal nu(mu)-nu(tau) oscillation in terms of bilinear R-violating terms in the superpotential associates comparable numbers of muons and tau's resulting from decays of the lightest neutralino. We show that this should lead to like-sign dimuons and ditaus with substantial rates, in a form that separates them from standard model backgrounds and other signals of supersymmetry. One here also has the possibility of completely reconstructing the lightest neutralino.
[ { "created": "Mon, 11 Oct 1999 13:53:48 GMT", "version": "v1" }, { "created": "Thu, 9 Nov 2000 11:22:49 GMT", "version": "v2" } ]
2009-10-31
[ [ "Datta", "Aseshkrishna", "" ], [ "Mukhopadhyaya", "Biswarup", "" ], [ "Vissani", "Francesco", "" ] ]
We show that an R-parity violating supersymmetric scenario which can account for the atmospheric nu(mu) deficit has testable signals at the Fermilab Tevatron with upgraded energy and luminosity. The explanation of neutrino masses and maximal nu(mu)-nu(tau) oscillation in terms of bilinear R-violating terms in the superpotential associates comparable numbers of muons and tau's resulting from decays of the lightest neutralino. We show that this should lead to like-sign dimuons and ditaus with substantial rates, in a form that separates them from standard model backgrounds and other signals of supersymmetry. One here also has the possibility of completely reconstructing the lightest neutralino.
2301.00076
Edilson Alfonso Reyes Rojas
E. A. Reyes R. and A. R. Fazio
Higgs Boson Mass Corrections at Three-Loops in the Top-Yukawa Sector of the Standard Model
10 pages, 4 figures
Phys. Rev. D 108, 053007, 2023
10.1103/PhysRevD.108.053007
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The search for new physics signals in Higgs precision measurements plays a pivotal role in the High-Luminosity Large Hadron Collider (HL-LHC) and future colliders programs. The Higgs properties are expected to be measured with great experimental precision, implying higher-order perturbative computations of the electroweak parameters from the theoretical side. In particular, the renormalized Higgs boson mass parameter in the Standard Model shows significant variation around the electroweak scale, resulting in a lower-bound theoretical uncertainty that exceeds future collider expectations. A more stable result under the renormalization group can be computed from a non-zero external momentum Higgs self-energy, for which available calculations include 3-loop corrections in the QCD sector. In this work, we present an additional contribution by estimating the leading non-QCD 3-loop corrections to the mass of the Higgs boson in the top-Yukawa sector of order $y_t^6$. The momentum-dependent Higgs self-energy is computed in the tadpole-free scheme for the Higgs vacuum expectation value in the Landau gauge, and the explicit dependence upon the Higgs boson and top quark masses is shown. The obtained result is expressed in dimensional regularization as a superposition of a set of master integrals with coefficients that are free of poles in four space-time dimensions, and the corrections are evaluated numerically by the sector decomposition method.
[ { "created": "Sat, 31 Dec 2022 00:03:11 GMT", "version": "v1" }, { "created": "Tue, 3 Jan 2023 22:06:44 GMT", "version": "v2" }, { "created": "Fri, 26 May 2023 19:41:11 GMT", "version": "v3" } ]
2023-09-22
[ [ "R.", "E. A. Reyes", "" ], [ "Fazio", "A. R.", "" ] ]
The search for new physics signals in Higgs precision measurements plays a pivotal role in the High-Luminosity Large Hadron Collider (HL-LHC) and future colliders programs. The Higgs properties are expected to be measured with great experimental precision, implying higher-order perturbative computations of the electroweak parameters from the theoretical side. In particular, the renormalized Higgs boson mass parameter in the Standard Model shows significant variation around the electroweak scale, resulting in a lower-bound theoretical uncertainty that exceeds future collider expectations. A more stable result under the renormalization group can be computed from a non-zero external momentum Higgs self-energy, for which available calculations include 3-loop corrections in the QCD sector. In this work, we present an additional contribution by estimating the leading non-QCD 3-loop corrections to the mass of the Higgs boson in the top-Yukawa sector of order $y_t^6$. The momentum-dependent Higgs self-energy is computed in the tadpole-free scheme for the Higgs vacuum expectation value in the Landau gauge, and the explicit dependence upon the Higgs boson and top quark masses is shown. The obtained result is expressed in dimensional regularization as a superposition of a set of master integrals with coefficients that are free of poles in four space-time dimensions, and the corrections are evaluated numerically by the sector decomposition method.
0710.2957
Yoshiaki Yasui
Y. Yasui, T. Ueda, E. de Doncker, J. Fujimoto, N. Hamaguchi, T. Ishikawa, Y. Shimizu and F. Yuasa
Status reports from the GRACE Group
6 pages, 3 figures, Proceedings for the International Workshop LCWS/ILC 2007, DESY in Hamburg, Germany, between May 30, 2007, and June 3, 2007
ECONF C0705302:LOOP04,2007
null
null
hep-ph
null
We discuss a new approach for the numerical evaluation of loop integrals. The fully numerical calculations of an infrared one-loop vertex and a box diagram are demonstrated. To perform these calculations, we apply an extrapolation method based on the $\epsilon$-algorithm. In our approach, the super high precision control in the numerical manipulation is essential to handle the infrared singularity. We adopt a multi-precision library named {\tt HMLib} for the precision control in the calculations.
[ { "created": "Tue, 16 Oct 2007 06:02:51 GMT", "version": "v1" } ]
2009-02-16
[ [ "Yasui", "Y.", "" ], [ "Ueda", "T.", "" ], [ "de Doncker", "E.", "" ], [ "Fujimoto", "J.", "" ], [ "Hamaguchi", "N.", "" ], [ "Ishikawa", "T.", "" ], [ "Shimizu", "Y.", "" ], [ "Yuasa", "F.", "" ] ]
We discuss a new approach for the numerical evaluation of loop integrals. The fully numerical calculations of an infrared one-loop vertex and a box diagram are demonstrated. To perform these calculations, we apply an extrapolation method based on the $\epsilon$-algorithm. In our approach, the super high precision control in the numerical manipulation is essential to handle the infrared singularity. We adopt a multi-precision library named {\tt HMLib} for the precision control in the calculations.
hep-ph/0303236
Patrick Meade
C. Csaki, J. Hubisz, G.D. Kribs, P. Meade, J. Terning
Variations of Little Higgs Models and their Electroweak Constraints
32 pages, 13 figures; revised discussion of SU(4)^4/SU(3)^4 model, bound on f is slightly higher
Phys.Rev.D68:035009,2003
10.1103/PhysRevD.68.035009
null
hep-ph
null
We calculate the tree-level electroweak precision constraints on a wide class of little Higgs models including: variations of the Littlest Higgs SU(5)/SO(5), SU(6)/Sp(6), and SU(4)^4/SU(3)^4. By performing a global fit to the precision data we find that for generic regions of the parameter space the bound on the symmetry breaking scale f is several TeV, where we have kept the normalization of f constant in the different models. For example, the ``minimal'' implementation of SU(6)/Sp(6) is bounded by f>3.0 TeV throughout most of the parameter space, and SU(4)^4/SU(3)^4 is bounded by f^2 = f_1^2+f_2^2 > (4.2 TeV)^2. In certain models, such as SU(4)^4/SU(3)^4, a large f does not directly imply a large amount of fine tuning since the heavy fermion masses that contribute to the Higgs mass can be lowered below f for a carefully chosen set of parameters. We also find that for certain models (or variations) there exist regions of parameter space in which the bound on f can be lowered into the range 1-2 TeV. These regions are typically characterized by a small mixing between heavy and standard model gauge bosons, and a small (or vanishing) coupling between heavy U(1) gauge bosons and the light fermions. Whether such a region of parameter space is natural or not is ultimately contingent on the UV completion.
[ { "created": "Fri, 28 Mar 2003 17:26:14 GMT", "version": "v1" }, { "created": "Thu, 17 Jul 2003 20:25:31 GMT", "version": "v2" } ]
2009-09-17
[ [ "Csaki", "C.", "" ], [ "Hubisz", "J.", "" ], [ "Kribs", "G. D.", "" ], [ "Meade", "P.", "" ], [ "Terning", "J.", "" ] ]
We calculate the tree-level electroweak precision constraints on a wide class of little Higgs models including: variations of the Littlest Higgs SU(5)/SO(5), SU(6)/Sp(6), and SU(4)^4/SU(3)^4. By performing a global fit to the precision data we find that for generic regions of the parameter space the bound on the symmetry breaking scale f is several TeV, where we have kept the normalization of f constant in the different models. For example, the ``minimal'' implementation of SU(6)/Sp(6) is bounded by f>3.0 TeV throughout most of the parameter space, and SU(4)^4/SU(3)^4 is bounded by f^2 = f_1^2+f_2^2 > (4.2 TeV)^2. In certain models, such as SU(4)^4/SU(3)^4, a large f does not directly imply a large amount of fine tuning since the heavy fermion masses that contribute to the Higgs mass can be lowered below f for a carefully chosen set of parameters. We also find that for certain models (or variations) there exist regions of parameter space in which the bound on f can be lowered into the range 1-2 TeV. These regions are typically characterized by a small mixing between heavy and standard model gauge bosons, and a small (or vanishing) coupling between heavy U(1) gauge bosons and the light fermions. Whether such a region of parameter space is natural or not is ultimately contingent on the UV completion.
hep-ph/9410319
Annemarie Blobel
Bernd A. Kniehl and Michael Spira
Two-Loop $ O(\alpha_sG_Fm_t^2)$ Correction to the $H\to b\bar b$ Decay Rate
16 p., Latex, 2 figures included (uuencoded PS-files), DESY 94-102
Nucl.Phys. B432 (1994) 39-48
10.1016/0550-3213(94)90592-4
null
hep-ph
null
We present the two-loop ${\cal O}(\alpha_sG_Fm_t^2)$ correction to the $b\bar b$ decay rate of the Stan\-dard-Model Higgs boson, assuming that the $t$ quark is much heavier than the Higgs boson. Apart from the universal correction connected with the renormalizations of the wave function and the vacuum expectation value of the Higgs field, this involves vertex corrections specific to the presence of beauty in the final state. We calculate the latter by means of a low-energy theorem. All would-be mass singularities related to the $b$ quark can be absorbed into the running Higgs-bottom Yukawa coupling. It turns out that the total ${\cal O}(\alpha_sG_Fm_t^2)$ correction screens the leading high-$m_t$ behaviour of the one-loop result by 71\% to 75\% for $M_H$ between 60~GeV and $2M_W$.
[ { "created": "Wed, 19 Oct 1994 13:33:03 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kniehl", "Bernd A.", "" ], [ "Spira", "Michael", "" ] ]
We present the two-loop ${\cal O}(\alpha_sG_Fm_t^2)$ correction to the $b\bar b$ decay rate of the Stan\-dard-Model Higgs boson, assuming that the $t$ quark is much heavier than the Higgs boson. Apart from the universal correction connected with the renormalizations of the wave function and the vacuum expectation value of the Higgs field, this involves vertex corrections specific to the presence of beauty in the final state. We calculate the latter by means of a low-energy theorem. All would-be mass singularities related to the $b$ quark can be absorbed into the running Higgs-bottom Yukawa coupling. It turns out that the total ${\cal O}(\alpha_sG_Fm_t^2)$ correction screens the leading high-$m_t$ behaviour of the one-loop result by 71\% to 75\% for $M_H$ between 60~GeV and $2M_W$.
0907.3270
Aram Kotzinian
Aram Kotzinian
Longitudinal target polarization dependence of anti-Lambda polarization and polarized strangeness PDFs
Typos corrected. Reference to slides added
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The longitudinal polarization of anti-Lambda produced in the currant fragmentation region of polarized lepton DIS off polarized and unpolarized target is described both in the simple formalism with factorized fragmentation functions as well as within intrinsic strangeness model using string fragmentation implemented into event generator LEPTO. It is demonstrated that the the measurement of anti-Lambda polarization and its dependence on the target polarization can serve as a filter for (un)polarized anti-strangeness distribution function of nucleon.
[ { "created": "Sun, 19 Jul 2009 08:21:33 GMT", "version": "v1" }, { "created": "Mon, 27 Jul 2009 11:39:42 GMT", "version": "v2" } ]
2009-07-27
[ [ "Kotzinian", "Aram", "" ] ]
The longitudinal polarization of anti-Lambda produced in the currant fragmentation region of polarized lepton DIS off polarized and unpolarized target is described both in the simple formalism with factorized fragmentation functions as well as within intrinsic strangeness model using string fragmentation implemented into event generator LEPTO. It is demonstrated that the the measurement of anti-Lambda polarization and its dependence on the target polarization can serve as a filter for (un)polarized anti-strangeness distribution function of nucleon.
1810.12002
Li Lin Yang
Xiaofeng Xu, Li Lin Yang
Towards a new approximation for pair-production and associated-production of the Higgs boson
v2: minor revisions
JHEP01(2019)211
10.1007/JHEP01(2019)211
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose that loop integrals with internal heavy particles can be evaluated by expanding in the limit of small external masses. This provides a systematically improvable approximation to the integrals in the entire phase space, and works particularly well for the high energy tails of kinematic distributions (where the usual $1/M$ expansions cease to be valid). We demonstrate our method using Higgs boson pair production as an example. We find that at both one-loop and two-loop, our method provides good approximations to the integrals appearing in the scattering amplitudes. Comparing to existing expansion methods, our method are not restricted to a special phase space region. Combining our efficient method to compute the two-loop amplitude with an infrared subtraction method for the real emission corrections, we expect to have a fast and reliable tool to calculate the differential cross sections for Higgs boson pair production. This will be useful for phenomenological studies and for the extraction of the Higgs self-coupling from future experimental data. Our method can also be applied to other processes, such as the associated production of the Higgs boson with a jet or a $Z$ boson.
[ { "created": "Mon, 29 Oct 2018 08:53:14 GMT", "version": "v1" }, { "created": "Wed, 16 Jan 2019 07:00:07 GMT", "version": "v2" } ]
2019-02-05
[ [ "Xu", "Xiaofeng", "" ], [ "Yang", "Li Lin", "" ] ]
We propose that loop integrals with internal heavy particles can be evaluated by expanding in the limit of small external masses. This provides a systematically improvable approximation to the integrals in the entire phase space, and works particularly well for the high energy tails of kinematic distributions (where the usual $1/M$ expansions cease to be valid). We demonstrate our method using Higgs boson pair production as an example. We find that at both one-loop and two-loop, our method provides good approximations to the integrals appearing in the scattering amplitudes. Comparing to existing expansion methods, our method are not restricted to a special phase space region. Combining our efficient method to compute the two-loop amplitude with an infrared subtraction method for the real emission corrections, we expect to have a fast and reliable tool to calculate the differential cross sections for Higgs boson pair production. This will be useful for phenomenological studies and for the extraction of the Higgs self-coupling from future experimental data. Our method can also be applied to other processes, such as the associated production of the Higgs boson with a jet or a $Z$ boson.
1108.3482
Jean-Paul Blaizot
Jean-Paul Blaizot
Quantum Fields at Finite Temperature "from tera to nano Kelvin"
Lectures delivered at Komaba campus of the University of Tokyo in November and December, 2009. Published in Soryushiron-kenkyu (e-version) http://www2.yukawa.kyoto-u.ac.jp/~sokened/sokendenshi/sokendenshi.htm
null
null
null
hep-ph cond-mat.quant-gas nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
These lectures introduce techniques that are used in the description of systems of particles and fields at high temperature (or density). These methods have a broad range of physical applications. We shall discuss two specific applications: one related to hot and dense matter composed of quarks and gluons, with temperatures in the tera Kelvin range, the other related to Bose-Einstein condensation in ultra-cold gases, with temperatures in the nano Kelvin range. As we shall see, in both systems, long wavelength collective phenomena lead to similar features, in spite of the huge difference in orders of magnitude of the respective energy scales.
[ { "created": "Wed, 17 Aug 2011 14:08:14 GMT", "version": "v1" } ]
2011-08-18
[ [ "Blaizot", "Jean-Paul", "" ] ]
These lectures introduce techniques that are used in the description of systems of particles and fields at high temperature (or density). These methods have a broad range of physical applications. We shall discuss two specific applications: one related to hot and dense matter composed of quarks and gluons, with temperatures in the tera Kelvin range, the other related to Bose-Einstein condensation in ultra-cold gases, with temperatures in the nano Kelvin range. As we shall see, in both systems, long wavelength collective phenomena lead to similar features, in spite of the huge difference in orders of magnitude of the respective energy scales.
hep-ph/0205089
Stanislaw Tatur
J. Bartelski and S. Tatur
A new determination of polarized parton densities in the nucleon
latex 12 pages, 3 eps figures
Acta Phys.Polon. B34 (2003) 2731-2740
null
null
hep-ph
null
In order to determine polarized parton distributions we have made a new NLO QCD fit using all experimental data on spin asymmetries measured in the deep inelastic scattering on different nucleon targets. The functional form of such densities is based on MRST 2001 results for unpolarized ones . We get for polarization of quarks (at Q^2 = 1 GeV^2): Delta u = 0.87, Delta d = -0.38, Delta s = -0.04. The total quark polarization is rather big and we obtain: Delta Sigma = 0.44. As a result of our fit we get a_3 = g_A = 1.24 the value which is close to experimental number. With negligible Delta s and rather big Delta Sigma (comparable to a_8) the results of our new fit are quite different in character from other fits.
[ { "created": "Thu, 9 May 2002 17:41:38 GMT", "version": "v1" }, { "created": "Mon, 29 Jul 2002 16:39:43 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bartelski", "J.", "" ], [ "Tatur", "S.", "" ] ]
In order to determine polarized parton distributions we have made a new NLO QCD fit using all experimental data on spin asymmetries measured in the deep inelastic scattering on different nucleon targets. The functional form of such densities is based on MRST 2001 results for unpolarized ones . We get for polarization of quarks (at Q^2 = 1 GeV^2): Delta u = 0.87, Delta d = -0.38, Delta s = -0.04. The total quark polarization is rather big and we obtain: Delta Sigma = 0.44. As a result of our fit we get a_3 = g_A = 1.24 the value which is close to experimental number. With negligible Delta s and rather big Delta Sigma (comparable to a_8) the results of our new fit are quite different in character from other fits.
2005.12424
Jonathan Rosner
Marek Karliner and Jonathan L. Rosner
Interpretation of excited $\Omega_b$ signals
12 pages, 1 figure. Version including proof corrections to be published in Phys. Rev. D
Phys. Rev. D 102, 014027 (2020)
10.1103/PhysRevD.102.014027
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently LHCb reported the discovery of four extremely narrow excited $\Omega_b$ baryons decaying into $\Xi_b^0 K^-$. We interpret these baryons as bound states of a $b$-quark and a $P$-wave $ss$-diquark. For such a system there are exactly five possible combinations of spin and orbital angular momentum. We predict two of spin 1/2, two of spin 3/2, and one of spin 5/2, all with negative parity. We favor identifying the observed states as those those with spins 1/2 and 3/2, and give a range of predicted masses for the one with spin 5/2. We update earlier predictions for these states based on the five narrow excited $\Omega_c$ states reported by LHCb. An alternative picture of the states in which one of $J=1/2$ is extremely wide and hence not seen by LHCb is discussed.
[ { "created": "Mon, 25 May 2020 21:58:22 GMT", "version": "v1" }, { "created": "Sun, 31 May 2020 19:55:59 GMT", "version": "v2" }, { "created": "Fri, 10 Jul 2020 23:03:15 GMT", "version": "v3" } ]
2020-07-22
[ [ "Karliner", "Marek", "" ], [ "Rosner", "Jonathan L.", "" ] ]
Recently LHCb reported the discovery of four extremely narrow excited $\Omega_b$ baryons decaying into $\Xi_b^0 K^-$. We interpret these baryons as bound states of a $b$-quark and a $P$-wave $ss$-diquark. For such a system there are exactly five possible combinations of spin and orbital angular momentum. We predict two of spin 1/2, two of spin 3/2, and one of spin 5/2, all with negative parity. We favor identifying the observed states as those those with spins 1/2 and 3/2, and give a range of predicted masses for the one with spin 5/2. We update earlier predictions for these states based on the five narrow excited $\Omega_c$ states reported by LHCb. An alternative picture of the states in which one of $J=1/2$ is extremely wide and hence not seen by LHCb is discussed.
hep-ph/9308321
JoAnne Hewett
J.L. Hewett
Extended Gauge Sectors at Linear Colliders
24 pages (figures + text, figures available by request), LaTex, ANL-HEP-CP-93-68
null
null
null
hep-ph
null
Signatures of extended gauge models at high energy \epem\ linear colliders are summarized. Talk presented at the Workshop on Physics and Experiments with Linear \epem\ Colliders, Waikoloa, Hawaii, April 1993.
[ { "created": "Mon, 23 Aug 1993 15:59:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hewett", "J. L.", "" ] ]
Signatures of extended gauge models at high energy \epem\ linear colliders are summarized. Talk presented at the Workshop on Physics and Experiments with Linear \epem\ Colliders, Waikoloa, Hawaii, April 1993.
2311.11327
Ulas Ozdem
U. \"Ozdem
Analysis of the $Z_b(10650)$ state based on electromagnetic properties
10 pages, 1 figure, version accepted by the European Physical Journal C
null
null
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
In this study, the magnetic and quadrupole moments of the $Z_b(10650)$ state are determined using the compact diquark-antidiquark interpolating current through the QCD light-cone sum rule. The values that are obtained as a result of the analysis are as follows: $\mu_{Z_b} = 2.35^{+0.34}_{-0.33}~\mu_N$ and $\mathcal{D}_{Z_b} =(1.82^{+0.35}_{-0.31})\times 10^{-2}~\mbox{fm}^2$. Examining the results obtained, it can be seen that the magnetic moments are large enough to be measured experimentally, while the quadrupole moment is obtained as a small but non-zero value, corresponding to a prolate charge distribution. The magnetic moment is the leading-order response of a bound system to a weak external magnetic field. It therefore provides an excellent platform to probe the internal structures of hadrons governed by the quark-gluon dynamics of QCD.
[ { "created": "Sun, 19 Nov 2023 13:47:46 GMT", "version": "v1" }, { "created": "Fri, 5 Jan 2024 17:26:55 GMT", "version": "v2" } ]
2024-01-08
[ [ "Özdem", "U.", "" ] ]
In this study, the magnetic and quadrupole moments of the $Z_b(10650)$ state are determined using the compact diquark-antidiquark interpolating current through the QCD light-cone sum rule. The values that are obtained as a result of the analysis are as follows: $\mu_{Z_b} = 2.35^{+0.34}_{-0.33}~\mu_N$ and $\mathcal{D}_{Z_b} =(1.82^{+0.35}_{-0.31})\times 10^{-2}~\mbox{fm}^2$. Examining the results obtained, it can be seen that the magnetic moments are large enough to be measured experimentally, while the quadrupole moment is obtained as a small but non-zero value, corresponding to a prolate charge distribution. The magnetic moment is the leading-order response of a bound system to a weak external magnetic field. It therefore provides an excellent platform to probe the internal structures of hadrons governed by the quark-gluon dynamics of QCD.
hep-ph/9904468
Andre Hoang
A.H. Hoang (CERN), T. Teubner (DESY, Hamburg)
Top Quark Pair Production close to Threshold: Top Mass, Width and Momentum Distribution
53 pages, latex; minor changes, a number of typos corrected
Phys.Rev. D60 (1999) 114027
10.1103/PhysRevD.60.114027
CERN-TH/99-59, DESY 99-047
hep-ph
null
The complete NNLO QCD corrections to the total cross section $\sigma(e^+e^- \to Z*,\gamma*\to t\bar t)$ in the kinematic region close to the top-antitop threshold are calculated by solving the corresponding Schroedinger equations exactly in momentum space in a consistent momentum cutoff regularization scheme. The corrections coming from the same NNLO QCD effects to the top quark three-momentum distribution $d\sigma/d |\vec k_t|$ are determined. We discuss the origin of the large NNLO corrections to the peak position and the normalization of the total cross section observed in previous works and propose a new top mass definition, the 1S mass M_1S, which stabilizes the peak in the total cross section. If the influence of beamstrahlung and initial state radiation on the mass determination is small, a theoretical uncertainty on the 1S top mass measurement of 200 MeV from the total cross section at the linear collider seems possible. We discuss how well the 1S mass can be related to the $\bar{MS}$ mass. We propose a consistent way to implement the top quark width at NNLO by including electroweak effects into the NRQCD matching coefficients, which then can become complex.
[ { "created": "Tue, 27 Apr 1999 16:41:35 GMT", "version": "v1" }, { "created": "Tue, 14 Sep 1999 09:58:37 GMT", "version": "v2" } ]
2009-10-31
[ [ "Hoang", "A. H.", "", "CERN" ], [ "Teubner", "T.", "", "DESY, Hamburg" ] ]
The complete NNLO QCD corrections to the total cross section $\sigma(e^+e^- \to Z*,\gamma*\to t\bar t)$ in the kinematic region close to the top-antitop threshold are calculated by solving the corresponding Schroedinger equations exactly in momentum space in a consistent momentum cutoff regularization scheme. The corrections coming from the same NNLO QCD effects to the top quark three-momentum distribution $d\sigma/d |\vec k_t|$ are determined. We discuss the origin of the large NNLO corrections to the peak position and the normalization of the total cross section observed in previous works and propose a new top mass definition, the 1S mass M_1S, which stabilizes the peak in the total cross section. If the influence of beamstrahlung and initial state radiation on the mass determination is small, a theoretical uncertainty on the 1S top mass measurement of 200 MeV from the total cross section at the linear collider seems possible. We discuss how well the 1S mass can be related to the $\bar{MS}$ mass. We propose a consistent way to implement the top quark width at NNLO by including electroweak effects into the NRQCD matching coefficients, which then can become complex.
1907.03379
Oleksandr Tomalak
Oleksandr Tomalak, Richard J Hill
Theory of elastic neutrino-electron scattering
54 pages, 20 figures. v2: journal version; minor corrections, Section 5.4 added, references and supplementary file added, appendix K extended
Phys. Rev. D 101, 033006 (2020)
10.1103/PhysRevD.101.033006
FERMILAB-PUB-19-076-T
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Theoretical predictions for elastic neutrino-electron scattering have no hadronic or nuclear uncertainties at leading order making this process an important tool for normalizing neutrino flux. However, the process is subject to large radiative corrections that differ according to experimental conditions. In this paper, we collect new and existing results for total and differential cross sections accompanied by radiation of one photon, $\nu e \to \nu e (\gamma)$. We perform calculations within the Fermi effective theory and provide analytic expressions for the electron energy spectrum and for the total electromagnetic energy spectrum as well as for double- and triple-differential cross sections with respect to electron energy, electron angle, photon energy, and photon angle. We discuss illustrative applications to accelerator-based neutrino experiments and provide the most precise up-to-date values of neutrino-electron scattering cross sections. We present an analysis of theoretical error, which is dominated by the $\sim 0.2 - 0.4\%$ uncertainty of the hadronic correction. We also discuss how searches for new physics can be affected by radiative corrections.
[ { "created": "Mon, 8 Jul 2019 01:37:15 GMT", "version": "v1" }, { "created": "Sat, 22 Feb 2020 13:59:58 GMT", "version": "v2" } ]
2020-02-26
[ [ "Tomalak", "Oleksandr", "" ], [ "Hill", "Richard J", "" ] ]
Theoretical predictions for elastic neutrino-electron scattering have no hadronic or nuclear uncertainties at leading order making this process an important tool for normalizing neutrino flux. However, the process is subject to large radiative corrections that differ according to experimental conditions. In this paper, we collect new and existing results for total and differential cross sections accompanied by radiation of one photon, $\nu e \to \nu e (\gamma)$. We perform calculations within the Fermi effective theory and provide analytic expressions for the electron energy spectrum and for the total electromagnetic energy spectrum as well as for double- and triple-differential cross sections with respect to electron energy, electron angle, photon energy, and photon angle. We discuss illustrative applications to accelerator-based neutrino experiments and provide the most precise up-to-date values of neutrino-electron scattering cross sections. We present an analysis of theoretical error, which is dominated by the $\sim 0.2 - 0.4\%$ uncertainty of the hadronic correction. We also discuss how searches for new physics can be affected by radiative corrections.
1304.6447
Mannque Rho
Hyun Kyu Lee and Mannque Rho
Dilatons in Dense Baryonic Matter
7 pages, no figures
null
10.1142/9789814566254_0036
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the role of dilaton, which is supposed to be representing a special feature of scale symmetry of QCD, trace anomaly, in dense baryonic matter. The idea that the scale symmetry breaking of QCD is responsible for the spontaneous breaking of chiral symmetry is presented along the similar spirit of Freund-Nambu model. The incorporation of dilaton field in the hidden local symmetric parity doublet model is briefly sketched with the possible role of dilaton at high density baryonic matter, the emergence of linear sigma model in dilaton limit.
[ { "created": "Wed, 24 Apr 2013 00:05:18 GMT", "version": "v1" } ]
2017-08-23
[ [ "Lee", "Hyun Kyu", "" ], [ "Rho", "Mannque", "" ] ]
We discuss the role of dilaton, which is supposed to be representing a special feature of scale symmetry of QCD, trace anomaly, in dense baryonic matter. The idea that the scale symmetry breaking of QCD is responsible for the spontaneous breaking of chiral symmetry is presented along the similar spirit of Freund-Nambu model. The incorporation of dilaton field in the hidden local symmetric parity doublet model is briefly sketched with the possible role of dilaton at high density baryonic matter, the emergence of linear sigma model in dilaton limit.
hep-ph/9807497
Krzysztof Golec-Biernat
K. Golec-Biernat and A. D. Martin
Off-diagonal parton distributions and their evolution
22 pages, Latex, 6 ps figures. Improved presentation after discussions with X.Ji and A.Radyushkin
Phys.Rev.D59:014029,1999
10.1103/PhysRevD.59.014029
DTP/98/48
hep-ph
null
We construct off-diagonal parton distributions defined on the interval 0 < X < 1 starting from the off-forward distributions defined by Ji. We emphasize the particular role played by the symmetry relations in the "ERBL-like" region. We find the evolution equations for the off-diagonal distributions which conserve these symmetries. We present numerical results of the evolution, and verify that the analytic asymptotic forms of the parton distributions are reproduced. We also compare the constructed off-diagonal distributions with the non-forward distributions defined by Radyushkin and comment on the singularity structure of the basic amplitude written in terms of the off-diagonal distributions.
[ { "created": "Sun, 26 Jul 1998 13:31:34 GMT", "version": "v1" }, { "created": "Wed, 12 Aug 1998 16:53:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Golec-Biernat", "K.", "" ], [ "Martin", "A. D.", "" ] ]
We construct off-diagonal parton distributions defined on the interval 0 < X < 1 starting from the off-forward distributions defined by Ji. We emphasize the particular role played by the symmetry relations in the "ERBL-like" region. We find the evolution equations for the off-diagonal distributions which conserve these symmetries. We present numerical results of the evolution, and verify that the analytic asymptotic forms of the parton distributions are reproduced. We also compare the constructed off-diagonal distributions with the non-forward distributions defined by Radyushkin and comment on the singularity structure of the basic amplitude written in terms of the off-diagonal distributions.
2106.10670
Georgii Shestakov
N.N. Achasov, A.V. Kiselev, G.N. Shestakov
Semileptonic decays $D\to\eta\pi e^+\nu_e$ in the $a_0(980)$ region
11 pages, 11 figures, v2: clarifications added, version published in Phys. Rev. D
Phys. Rev. D 104, 016034 (2021)
10.1103/PhysRevD.104.016034
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mechanism of the four-quark production of the light scalar isovector four-quark state $a_0(980)$ in the $D\to\eta\pi e^+\nu_e$ decays is discussed. It is shown that the characteristic features of the shape of the $\eta\pi$ mass spectra expected in our scheme can serve as the indicator of the production mechanism and internal structure of the $a_0(980)$ resonance.
[ { "created": "Sun, 20 Jun 2021 10:23:33 GMT", "version": "v1" }, { "created": "Sat, 31 Jul 2021 04:48:20 GMT", "version": "v2" } ]
2021-08-04
[ [ "Achasov", "N. N.", "" ], [ "Kiselev", "A. V.", "" ], [ "Shestakov", "G. N.", "" ] ]
The mechanism of the four-quark production of the light scalar isovector four-quark state $a_0(980)$ in the $D\to\eta\pi e^+\nu_e$ decays is discussed. It is shown that the characteristic features of the shape of the $\eta\pi$ mass spectra expected in our scheme can serve as the indicator of the production mechanism and internal structure of the $a_0(980)$ resonance.
0901.4677
Sourendu Gupta
Rajeev S. Bhalerao and Sourendu Gupta
Relativistic diffusion and heavy-ion collisions
8 pages, 5 figures
Phys.Rev.C79:064901,2009
10.1103/PhysRevC.79.064901
TIFR/TH/09-05
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study first and second order theories of relativistic diffusion coupled to hydrodynamics under the approximation, valid at mid-rapidity in the RHIC and LHC, that conserved number densities are much smaller than the entropy density. We identify experimentally accessible quantities of interest, and show that the first and second order theories may lead to radically different evolutions of these quantities. In the first order theory the memory of the initial state is almost completely washed out, whereas in the second order theory it is possible that freezeout occurs at a time when transient dynamics is still on, and the memory of the initial state remains. There are observational consequences which we touch upon. In the first order theory, and for initial conditions when the second order theory mimics the first order, one may be able to put a bound on the diffusion constant.
[ { "created": "Thu, 29 Jan 2009 13:37:03 GMT", "version": "v1" }, { "created": "Tue, 24 Feb 2009 09:32:35 GMT", "version": "v2" } ]
2009-11-19
[ [ "Bhalerao", "Rajeev S.", "" ], [ "Gupta", "Sourendu", "" ] ]
We study first and second order theories of relativistic diffusion coupled to hydrodynamics under the approximation, valid at mid-rapidity in the RHIC and LHC, that conserved number densities are much smaller than the entropy density. We identify experimentally accessible quantities of interest, and show that the first and second order theories may lead to radically different evolutions of these quantities. In the first order theory the memory of the initial state is almost completely washed out, whereas in the second order theory it is possible that freezeout occurs at a time when transient dynamics is still on, and the memory of the initial state remains. There are observational consequences which we touch upon. In the first order theory, and for initial conditions when the second order theory mimics the first order, one may be able to put a bound on the diffusion constant.
0907.0667
Carlos A. Salgado
Nestor Armesto, Matteo Cacciari, Tetsufumi Hirano, James L. Nagle and Carlos A. Salgado
Constraint fitting of experimental data with a jet quenching model embedded in a hydrodynamical bulk medium
21 pages, 11 eps figures. Experimental errors in figures 4-6 and minor misprints corrected
J.Phys.G37:025104,2010
10.1088/0954-3899/37/2/025104
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a global fit to single- and double-inclusive suppression data of high-$p_T$ particles in central Au+Au collisions at top RHIC energy. We also include in this analysis data on heavy quarks via their D and B meson semi-leptonic decays (i.e. non-photonic electrons). The analysis is based on the parton quenching weights for medium-induced gluon radiation computed in the BDMPS approximation then embedded in a hydrodynamical description of the bulk medium. Our results indicate that values of the transport coefficient $\hat q$ more than four times larger than perturbative estimates are preferred by experimental data. This confirms previous calculations based on simpler implementations of the medium geometry or only the single-inclusive suppression. We also comment on the statistical compatibility of the heavy quark data within a radiative only energy loss scenario, and on the sensitivity of the results to nuclear modification of the parton distribution functions (PDFs) and to assumptions on the energy loss during times in the collision prior to the hydrodynamical behavior.}
[ { "created": "Fri, 3 Jul 2009 16:35:10 GMT", "version": "v1" }, { "created": "Thu, 3 Dec 2009 12:01:11 GMT", "version": "v2" } ]
2010-01-21
[ [ "Armesto", "Nestor", "" ], [ "Cacciari", "Matteo", "" ], [ "Hirano", "Tetsufumi", "" ], [ "Nagle", "James L.", "" ], [ "Salgado", "Carlos A.", "" ] ]
We present a global fit to single- and double-inclusive suppression data of high-$p_T$ particles in central Au+Au collisions at top RHIC energy. We also include in this analysis data on heavy quarks via their D and B meson semi-leptonic decays (i.e. non-photonic electrons). The analysis is based on the parton quenching weights for medium-induced gluon radiation computed in the BDMPS approximation then embedded in a hydrodynamical description of the bulk medium. Our results indicate that values of the transport coefficient $\hat q$ more than four times larger than perturbative estimates are preferred by experimental data. This confirms previous calculations based on simpler implementations of the medium geometry or only the single-inclusive suppression. We also comment on the statistical compatibility of the heavy quark data within a radiative only energy loss scenario, and on the sensitivity of the results to nuclear modification of the parton distribution functions (PDFs) and to assumptions on the energy loss during times in the collision prior to the hydrodynamical behavior.}
0902.2934
Philipp M. Kostka
Stefan Antusch, Koushik Dutta and Philipp M. Kostka (MPI, Munich)
SUGRA Hybrid Inflation with Shift Symmetry
7 pages, 3 figures; appendix and references added; version published in PLB
Phys.Lett.B677:221-225,2009
10.1016/j.physletb.2009.05.043
MPP-2009-18
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a solution to the eta-problem in supergravity (SUGRA) hybrid inflation using a Nambu-Goldstone-like shift symmetry within a new class of models. The flatness of the tree-level inflaton potential is ensured by shift symmetry invariance of the Kaehler potential, while a small symmetry breaking term in the superpotential gives rise to a slope of the potential at loop-level. In the proposed class of inflation models, potentially dangerous couplings between the inflaton and the moduli sector are avoided. We also discuss under which conditions the predicted spectral index can be in agreement with the best-fit-value of the latest WMAP observation n_s ~ 0.96, corresponding to a hilltop-type inflaton potential at loop-level.
[ { "created": "Tue, 17 Feb 2009 15:16:05 GMT", "version": "v1" }, { "created": "Wed, 17 Jun 2009 14:08:57 GMT", "version": "v2" } ]
2010-04-21
[ [ "Antusch", "Stefan", "", "MPI, Munich" ], [ "Dutta", "Koushik", "", "MPI, Munich" ], [ "Kostka", "Philipp M.", "", "MPI, Munich" ] ]
We propose a solution to the eta-problem in supergravity (SUGRA) hybrid inflation using a Nambu-Goldstone-like shift symmetry within a new class of models. The flatness of the tree-level inflaton potential is ensured by shift symmetry invariance of the Kaehler potential, while a small symmetry breaking term in the superpotential gives rise to a slope of the potential at loop-level. In the proposed class of inflation models, potentially dangerous couplings between the inflaton and the moduli sector are avoided. We also discuss under which conditions the predicted spectral index can be in agreement with the best-fit-value of the latest WMAP observation n_s ~ 0.96, corresponding to a hilltop-type inflaton potential at loop-level.
hep-ph/0212221
Norma Mankoc Borstnik
N. S. Mankoc Borstnik, C. D. Froggatt, D. Lukman, M. Axenides, D. Melikhov, B. Stech, D.B. Fairlie, P.H. Frampton, J.W. van Holten, J.L. Petersen, L.V. Laperashvili, D.A. Ryzhikh, P. Olesen, L. Susskind, S.I. Blinnikov, L.B. Okun, M.I. Vysotsky, Jeff Greensite
Proceedings to the Workshops ''What comes beyond the Standard model'' 2000,2001, VOLUME 1: Festschrift dedicated to the 60th birthday of Holger Bech Nielsen
The proceedings includes 13 papers of different authors. Editors were N. S. Mankoc Borstnik, C. D. Froggatt, D. Lukman
Bled workshops in physics, Volume 2, No.2, DMFA Zaloznistvo, Ljubljana, Dec. 2001
null
null
hep-ph
null
The present volume is the collection of contributions by friends of Holger Bech Nielsen for his 60th birthday. Contents: 1.Unified internal space of spins and charges (N. Mankoc Borstnik) 2.Semitopological Q-Rings (M. Axenides) 3.Non-local axial anomalies in the Standard model (D. Melikhov, B. Stech) 4.Could there be a fourth generation? (C.D. Froggatt) 5.Another complex Bateman equation (D.B. Fairlie) 6.Non-associative loops for Holger Bech Nielsen (P.H. Frampton) 7.Particles, fluids and vortices (J.W. van Holten) 8.Results on 2D current algebras (J.L. Petersen) 9.Phase transition in gauge theories and the Planck scale physics (L.V. Laperashvili and D.A. Ryzhikh) 10.Some remarks on the 'classical' large N limit (P. Olesen) 11.String theory and the size of hadrons (L. Susskind) 12.Relativity and $c/sqrt3$ (S.I. Blinnikov, L.B. Okun and M.I. Vysotsky) 13.Vortices (Jeff Greensite)
[ { "created": "Mon, 16 Dec 2002 13:03:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Borstnik", "N. S. Mankoc", "" ], [ "Froggatt", "C. D.", "" ], [ "Lukman", "D.", "" ], [ "Axenides", "M.", "" ], [ "Melikhov", "D.", "" ], [ "Stech", "B.", "" ], [ "Fairlie", "D. B.", "" ], [ "Frampton", "P. H.", "" ], [ "van Holten", "J. W.", "" ], [ "Petersen", "J. L.", "" ], [ "Laperashvili", "L. V.", "" ], [ "Ryzhikh", "D. A.", "" ], [ "Olesen", "P.", "" ], [ "Susskind", "L.", "" ], [ "Blinnikov", "S. I.", "" ], [ "Okun", "L. B.", "" ], [ "Vysotsky", "M. I.", "" ], [ "Greensite", "Jeff", "" ] ]
The present volume is the collection of contributions by friends of Holger Bech Nielsen for his 60th birthday. Contents: 1.Unified internal space of spins and charges (N. Mankoc Borstnik) 2.Semitopological Q-Rings (M. Axenides) 3.Non-local axial anomalies in the Standard model (D. Melikhov, B. Stech) 4.Could there be a fourth generation? (C.D. Froggatt) 5.Another complex Bateman equation (D.B. Fairlie) 6.Non-associative loops for Holger Bech Nielsen (P.H. Frampton) 7.Particles, fluids and vortices (J.W. van Holten) 8.Results on 2D current algebras (J.L. Petersen) 9.Phase transition in gauge theories and the Planck scale physics (L.V. Laperashvili and D.A. Ryzhikh) 10.Some remarks on the 'classical' large N limit (P. Olesen) 11.String theory and the size of hadrons (L. Susskind) 12.Relativity and $c/sqrt3$ (S.I. Blinnikov, L.B. Okun and M.I. Vysotsky) 13.Vortices (Jeff Greensite)
hep-ph/0406330
Thomas A. Trainor
R.J. Porter and T.A. Trainor
Soft and hard components of two-particle distributions on ($y_t,\eta,\phi$) from p-p collisions at $\sqrt{s} = 200$ GeV
3 pages, 4 figures, Quark Matter 2004 poster writeup
null
null
null
hep-ph
null
We report measurements of large-scale two-particle correlations for 200 GeV p-p collisions on momentum components transverse rapidity $y_t$ (pion mass assigned), pseudorapidity $\eta$ and azimuth angle $\phi$. In both transverse $y_t \otimes y_t$ and axial $(\eta\otimes\eta,\phi\otimes\phi) $ two-particle subspaces we observe two components of correlation structure (soft and hard) which we interpret respectively in terms of longitudinal string fragmentation and transverse minimum-bias parton fragmentation (minijets). This combination is also represented by Lund-model-based Monte Carlo simulations such as Pythia.
[ { "created": "Tue, 29 Jun 2004 23:43:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Porter", "R. J.", "" ], [ "Trainor", "T. A.", "" ] ]
We report measurements of large-scale two-particle correlations for 200 GeV p-p collisions on momentum components transverse rapidity $y_t$ (pion mass assigned), pseudorapidity $\eta$ and azimuth angle $\phi$. In both transverse $y_t \otimes y_t$ and axial $(\eta\otimes\eta,\phi\otimes\phi) $ two-particle subspaces we observe two components of correlation structure (soft and hard) which we interpret respectively in terms of longitudinal string fragmentation and transverse minimum-bias parton fragmentation (minijets). This combination is also represented by Lund-model-based Monte Carlo simulations such as Pythia.
0707.3090
Thomas Schutzmeier
R. Boughezal, M. Czakon, T. Schutzmeier
NNLO fermionic corrections to the charm quark mass dependent matrix elements in B -> X_s gamma
11 pages, 3 figures, 1 table
JHEP 0709:072,2007
10.1088/1126-6708/2007/09/072
null
hep-ph
null
We compute the virtual O(alpha_s^2) fermionic contributions to the charm quark mass dependent matrix elements of the B -> X_s gamma decay. In the case of a massless quark loop insertion into the gluon propagator, our result obtained as an expansion in z=m_c^2/m_b^2 and an exact expression in terms of multi-fold MB integrals, confirms the findings of Bieri, Greub and Steinhauser [19]. We observe, however, large deviations in the case of a b-quark loop insertion.The charm quark loop shows smaller, but still noticeable differences.
[ { "created": "Fri, 20 Jul 2007 15:27:50 GMT", "version": "v1" }, { "created": "Fri, 3 Aug 2007 09:11:17 GMT", "version": "v2" } ]
2009-02-18
[ [ "Boughezal", "R.", "" ], [ "Czakon", "M.", "" ], [ "Schutzmeier", "T.", "" ] ]
We compute the virtual O(alpha_s^2) fermionic contributions to the charm quark mass dependent matrix elements of the B -> X_s gamma decay. In the case of a massless quark loop insertion into the gluon propagator, our result obtained as an expansion in z=m_c^2/m_b^2 and an exact expression in terms of multi-fold MB integrals, confirms the findings of Bieri, Greub and Steinhauser [19]. We observe, however, large deviations in the case of a b-quark loop insertion.The charm quark loop shows smaller, but still noticeable differences.
2309.09743
Humberto Reyes-Gonz\'alez
Humberto Reyes-Gonzalez, Riccardo Torre
The NFLikelihood: an unsupervised DNNLikelihood from Normalizing Flows
16 pages, 5 figures, 11 tables. Minor revision
null
null
null
hep-ph cs.LG hep-ex
http://creativecommons.org/licenses/by/4.0/
We propose the NFLikelihood, an unsupervised version, based on Normalizing Flows, of the DNNLikelihood proposed in Ref.[1]. We show, through realistic examples, how Autoregressive Flows, based on affine and rational quadratic spline bijectors, are able to learn complicated high-dimensional Likelihoods arising in High Energy Physics (HEP) analyses. We focus on a toy LHC analysis example already considered in the literature and on two Effective Field Theory fits of flavor and electroweak observables, whose samples have been obtained throught the HEPFit code. We discuss advantages and disadvantages of the unsupervised approach with respect to the supervised one and discuss possible interplays of the two.
[ { "created": "Mon, 18 Sep 2023 13:13:47 GMT", "version": "v1" }, { "created": "Tue, 9 Apr 2024 13:14:45 GMT", "version": "v2" }, { "created": "Thu, 16 May 2024 15:05:14 GMT", "version": "v3" } ]
2024-05-17
[ [ "Reyes-Gonzalez", "Humberto", "" ], [ "Torre", "Riccardo", "" ] ]
We propose the NFLikelihood, an unsupervised version, based on Normalizing Flows, of the DNNLikelihood proposed in Ref.[1]. We show, through realistic examples, how Autoregressive Flows, based on affine and rational quadratic spline bijectors, are able to learn complicated high-dimensional Likelihoods arising in High Energy Physics (HEP) analyses. We focus on a toy LHC analysis example already considered in the literature and on two Effective Field Theory fits of flavor and electroweak observables, whose samples have been obtained throught the HEPFit code. We discuss advantages and disadvantages of the unsupervised approach with respect to the supervised one and discuss possible interplays of the two.
hep-ph/9812398
J. Raufeisen
J. Raufeisen, A.V. Tarasov and O.O. Voskresenskaya
Nuclear Shadowing in DIS at Moderately Small $x_B$
10 pages, 1 figure, uses svjour, svepj, minor misprints corrected, results unchanged
Eur.Phys.J. A5 (1999) 173-182
null
null
hep-ph
null
In the rest frame of the nucleus, shadowing is due to hadronic fluctuations of the incoming virtual photon, which interact with the nucleons. We expand these fluctuations in a basis of eigenstates of interaction and take only the $q\bar q$ component of the hadronic structure of the photon into account. We use a representation in which the $q\bar q$-pair has a definite transverse size. Starting from the Dirac equation, we develop a path integral approach that allows to sum all multiple scattering terms and accounts for fluctuations of the transverse size of the pair, as well as for the finite lifetime of the hadronic state. First numerical results hep-ph/9807211 have shown that higher order scattering terms have a strong influence on the total cross section $\sigma^{\gamma^*A}_{tot}$. The aim of this paper is to give a detailed derivation of the formula for the total cross section.
[ { "created": "Wed, 16 Dec 1998 20:44:58 GMT", "version": "v1" }, { "created": "Fri, 26 Feb 1999 18:43:44 GMT", "version": "v2" }, { "created": "Tue, 9 Mar 1999 18:44:40 GMT", "version": "v3" } ]
2007-05-23
[ [ "Raufeisen", "J.", "" ], [ "Tarasov", "A. V.", "" ], [ "Voskresenskaya", "O. O.", "" ] ]
In the rest frame of the nucleus, shadowing is due to hadronic fluctuations of the incoming virtual photon, which interact with the nucleons. We expand these fluctuations in a basis of eigenstates of interaction and take only the $q\bar q$ component of the hadronic structure of the photon into account. We use a representation in which the $q\bar q$-pair has a definite transverse size. Starting from the Dirac equation, we develop a path integral approach that allows to sum all multiple scattering terms and accounts for fluctuations of the transverse size of the pair, as well as for the finite lifetime of the hadronic state. First numerical results hep-ph/9807211 have shown that higher order scattering terms have a strong influence on the total cross section $\sigma^{\gamma^*A}_{tot}$. The aim of this paper is to give a detailed derivation of the formula for the total cross section.
hep-ph/9501336
null
Zurab Berezhiani (INFN, Ferrara), Csaba Csaki and Lisa Randall (MIT)
Could the Supersymmetric Higgs Particles Naturally be Pseudo-Goldstone Bosons?
39 pages, plain LaTeX
Nucl.Phys.B444:61-91,1995
10.1016/0550-3213(95)00183-S
INFN-FE 01-95, MIT-CTP-2404
hep-ph
null
The doublet-triplet splitting problem is perhaps the most problematic aspect of supersymmetric grand unified theories. It can be argued that the most natural reason for the Higgs doublets to be light is that they are pseudo-Goldstone bosons associated with the spontaneous breakdown of an accidental global symmetry. In this paper we discuss the possibility of implementing this idea in the SU(6) model of refs. \cite{Zur,Bar2,Bar3,Bar4}. We show that although it is simple to generate an accidental symmetry of the renormalizable terms of the potential, it is quite difficult to construct a model which allows for the preservation of the accidental symmetry in the nonrenormalizable terms. We summarize the constraints on such models and then give three different ways to construct a superpotential where the dangerous mixing terms are sufficiently suppressed even in the presence of nonrenormalizable operators. With these examples we demonstrate the existence of consistent models implementing the Higgs as pseudo-Goldstone boson scheme. We extend one of the three examples to include fermion masses. We also show that when restricted to regular group embeddings the only possible models without light triplets are trivial generalizations of the SU(6) model we consider.
[ { "created": "Wed, 18 Jan 1995 22:29:32 GMT", "version": "v1" } ]
2016-09-01
[ [ "Berezhiani", "Zurab", "", "INFN, Ferrara" ], [ "Csaki", "Csaba", "", "MIT" ], [ "Randall", "Lisa", "", "MIT" ] ]
The doublet-triplet splitting problem is perhaps the most problematic aspect of supersymmetric grand unified theories. It can be argued that the most natural reason for the Higgs doublets to be light is that they are pseudo-Goldstone bosons associated with the spontaneous breakdown of an accidental global symmetry. In this paper we discuss the possibility of implementing this idea in the SU(6) model of refs. \cite{Zur,Bar2,Bar3,Bar4}. We show that although it is simple to generate an accidental symmetry of the renormalizable terms of the potential, it is quite difficult to construct a model which allows for the preservation of the accidental symmetry in the nonrenormalizable terms. We summarize the constraints on such models and then give three different ways to construct a superpotential where the dangerous mixing terms are sufficiently suppressed even in the presence of nonrenormalizable operators. With these examples we demonstrate the existence of consistent models implementing the Higgs as pseudo-Goldstone boson scheme. We extend one of the three examples to include fermion masses. We also show that when restricted to regular group embeddings the only possible models without light triplets are trivial generalizations of the SU(6) model we consider.
1609.05849
Marcos A. Garcia Garcia
John Ellis, Marcos A. G. Garcia, Natsumi Nagata, Dimitri V. Nanopoulos, Keith A. Olive
Starobinsky-Like Inflation and Neutrino Masses in a No-Scale SO(10) Model
38 pages, 8 figures
null
10.1088/1475-7516/2016/11/018
KCL-PH-TH/2016-54, CERN-PH-TH/2016-18, UT-16-29, ACT-05-16, MI-TH-162, UMN-TH-3603/16, FTPI-MINN-16/26
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using a no-scale supergravity framework, we construct an SO(10) model that makes predictions for cosmic microwave background observables similar to those of the Starobinsky model of inflation, and incorporates a double-seesaw model for neutrino masses consistent with oscillation experiments and late-time cosmology. We pay particular attention to the behaviour of the scalar fields during inflation and the subsequent reheating.
[ { "created": "Mon, 19 Sep 2016 18:28:25 GMT", "version": "v1" } ]
2016-11-15
[ [ "Ellis", "John", "" ], [ "Garcia", "Marcos A. G.", "" ], [ "Nagata", "Natsumi", "" ], [ "Nanopoulos", "Dimitri V.", "" ], [ "Olive", "Keith A.", "" ] ]
Using a no-scale supergravity framework, we construct an SO(10) model that makes predictions for cosmic microwave background observables similar to those of the Starobinsky model of inflation, and incorporates a double-seesaw model for neutrino masses consistent with oscillation experiments and late-time cosmology. We pay particular attention to the behaviour of the scalar fields during inflation and the subsequent reheating.
1703.05750
Ivo de Medeiros Varzielas
Ivo de Medeiros Varzielas
CP-odd invariants for multi-Higgs models and applications with discrete symmetry
9 pages. Contribution to the proceedings of DISCRETE 2016, Warsaw
null
10.1088/1742-6596/873/1/012035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
CP-odd invariants are useful for studying the CP properties of Lagrangians in any basis. We explain how to build basis invariants for the scalar sector, and how to distinguish CP-odd invariants from CP-even invariants. Up to a certain order, we use these methods to systematically build all the CP-odd invariants. The CP-odd invariants signal either explicit or spontaneous violation of CP. Making use of the CP-odd invariants, we determine the CP properties of potentials with 3 and with 6 Higgs fields arranged as triplets of specific discrete symmetries in the $\Delta(3n^2)$ or $\Delta(6n^2)$ series (inlcuding $A_4$, $S_4$, $\Delta(27)$ and $\Delta(54)$ as well as the cases for $n>3$).
[ { "created": "Thu, 16 Mar 2017 17:50:00 GMT", "version": "v1" } ]
2017-09-13
[ [ "Varzielas", "Ivo de Medeiros", "" ] ]
CP-odd invariants are useful for studying the CP properties of Lagrangians in any basis. We explain how to build basis invariants for the scalar sector, and how to distinguish CP-odd invariants from CP-even invariants. Up to a certain order, we use these methods to systematically build all the CP-odd invariants. The CP-odd invariants signal either explicit or spontaneous violation of CP. Making use of the CP-odd invariants, we determine the CP properties of potentials with 3 and with 6 Higgs fields arranged as triplets of specific discrete symmetries in the $\Delta(3n^2)$ or $\Delta(6n^2)$ series (inlcuding $A_4$, $S_4$, $\Delta(27)$ and $\Delta(54)$ as well as the cases for $n>3$).
1706.01765
Roman Pasechnik
Yoshikazu Hagiwara, Yoshitaka Hatta, Roman Pasechnik, Marek Tasevsky and Oleg Teryaev
Accessing the gluon Wigner distribution in ultraperipheral $pA$ collisions
12 pages, 6 figures; a minor fix to Eq. (15); conclusions unchanged
Phys. Rev. D 96, 034009 (2017)
10.1103/PhysRevD.96.034009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose to constrain the gluon Wigner distribution in the nucleon by studying the exclusive diffractive dijet production process in ultraperipheral proton-nucleus collisions (UPCs) at RHIC and the LHC. Compared to the previous proposal in Ref. [Y. Hatta, B. W. Xiao, and F. Yuan, Phys. Rev. Lett. 116, 202301 (2016).] to study the same observable in lepton-nucleon scattering, the use of UPCs has a few advantages: not only is the cross section larger, but the extraction of the Wigner distribution from the data also becomes simpler, including its elliptic angular dependence. We compute the corresponding cross section and evaluate the coefficients using models which include the gluon saturation effects. A potential for the measurements of the Wigner distribution at current and future experimental facilities is also discussed.
[ { "created": "Tue, 6 Jun 2017 13:45:38 GMT", "version": "v1" }, { "created": "Sat, 12 Aug 2017 16:58:51 GMT", "version": "v2" }, { "created": "Fri, 1 Dec 2017 15:48:19 GMT", "version": "v3" } ]
2017-12-04
[ [ "Hagiwara", "Yoshikazu", "" ], [ "Hatta", "Yoshitaka", "" ], [ "Pasechnik", "Roman", "" ], [ "Tasevsky", "Marek", "" ], [ "Teryaev", "Oleg", "" ] ]
We propose to constrain the gluon Wigner distribution in the nucleon by studying the exclusive diffractive dijet production process in ultraperipheral proton-nucleus collisions (UPCs) at RHIC and the LHC. Compared to the previous proposal in Ref. [Y. Hatta, B. W. Xiao, and F. Yuan, Phys. Rev. Lett. 116, 202301 (2016).] to study the same observable in lepton-nucleon scattering, the use of UPCs has a few advantages: not only is the cross section larger, but the extraction of the Wigner distribution from the data also becomes simpler, including its elliptic angular dependence. We compute the corresponding cross section and evaluate the coefficients using models which include the gluon saturation effects. A potential for the measurements of the Wigner distribution at current and future experimental facilities is also discussed.
1810.05454
Filipe Rafael Joaquim
D. M. Barreiros, R. G. Felipe and F. R. Joaquim
Combining texture zeros with a remnant CP symmetry in the minimal type-I seesaw
29 pages, 8 figures. Analysis redone using a more suitable parameterisation for the lepton mixing matrix. New results included, main conclusions unchanged. References added. Final version published in JHEP
null
10.1007/JHEP01(2019)223
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of the two right-handed neutrino seesaw model, we consider maximally-restrictive texture-zero patterns for the lepton Yukawa coupling and mass matrices, together with the existence of a remnant CP symmetry. Under these premisses, we find that several textures are compatible with the most recent data coming from neutrino oscillation and neutrinoless double beta decay experiments. It is shown that the number of allowed texture zeros depends on the type of heavy right-handed neutrino mass spectrum. Namely, at most one (two)-zero patterns are allowed in the Dirac Yukawa coupling matrix for nondegenerate (degenerate) heavy Majorana neutrinos. The predictions for the low-energy Dirac and Majorana CP-violating phases, and for the effective mass parameter relevant in neutrinoless double-beta decay experiments, are presented and discussed. We also comment on the impact of future experimental improvements in scrutinising texture-zero patterns with a remnant CP symmetry, within the minimal version of the seesaw mechanism considered here.
[ { "created": "Fri, 12 Oct 2018 11:32:11 GMT", "version": "v1" }, { "created": "Wed, 27 Feb 2019 19:09:13 GMT", "version": "v2" } ]
2019-03-01
[ [ "Barreiros", "D. M.", "" ], [ "Felipe", "R. G.", "" ], [ "Joaquim", "F. R.", "" ] ]
In the framework of the two right-handed neutrino seesaw model, we consider maximally-restrictive texture-zero patterns for the lepton Yukawa coupling and mass matrices, together with the existence of a remnant CP symmetry. Under these premisses, we find that several textures are compatible with the most recent data coming from neutrino oscillation and neutrinoless double beta decay experiments. It is shown that the number of allowed texture zeros depends on the type of heavy right-handed neutrino mass spectrum. Namely, at most one (two)-zero patterns are allowed in the Dirac Yukawa coupling matrix for nondegenerate (degenerate) heavy Majorana neutrinos. The predictions for the low-energy Dirac and Majorana CP-violating phases, and for the effective mass parameter relevant in neutrinoless double-beta decay experiments, are presented and discussed. We also comment on the impact of future experimental improvements in scrutinising texture-zero patterns with a remnant CP symmetry, within the minimal version of the seesaw mechanism considered here.
hep-ph/0511181
Wahkeung Sze
W. K. Sze
The Fritzsch Ansatz Revisited
7 pages
null
null
null
hep-ph
null
A modified Fritzsch ansatz for the quark mass matrices is proposed to account for the hierarchical structure of the CKM matrix. To allow for the observed CP asymmetry, restrictions have to be imposed on the relative phase degree of freedom among the weak eigenstates of the quark fields, as for example by certain additional symmetries. The ansatz can be accommodated in extensions to the Standard Model, such as the multiple Higgs doublets models.
[ { "created": "Tue, 15 Nov 2005 09:57:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sze", "W. K.", "" ] ]
A modified Fritzsch ansatz for the quark mass matrices is proposed to account for the hierarchical structure of the CKM matrix. To allow for the observed CP asymmetry, restrictions have to be imposed on the relative phase degree of freedom among the weak eigenstates of the quark fields, as for example by certain additional symmetries. The ansatz can be accommodated in extensions to the Standard Model, such as the multiple Higgs doublets models.
2006.10951
Adriano Lana Cherchiglia
A. Cherchiglia, D. C. Arias-Perdomo, A. R. Vieira, M. Sampaio, and B. Hiller
Two-loop renormalisation of gauge theories in $4D$ Implicit Regularisation and connections to dimensional methods
Section 2 expanded, references revised, misprints corrected. Final results unchanged. Comply with published version
null
10.1140/epjc/s10052-021-09259-6
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We compute the two-loop $\beta$-function of scalar and spinorial quantum electrodynamics as well as pure Yang-Mills and quantum chromodynamics using the background field method in a fully quadridimensional setup using Implicit Regularization (IREG). Moreover, a thorough comparison with dimensional approaches such as conventional dimensional regularization (CDR) and dimensional reduction (DRED) is presented. Subtleties related to Lorentz algebra contractions/symmetric integrations inside divergent integrals as well as renormalisation schemes are carefully discussed within IREG where the renormalisation constants are fully defined as basic divergent integrals to arbitrary loop order. Moreover, we confirm the hypothesis that momentum routing invariance in the loops of Feynman diagrams implemented via setting well-defined surface terms to zero deliver non-abelian gauge invariant amplitudes within IREG just as it has been proven for abelian theories.
[ { "created": "Fri, 19 Jun 2020 04:09:49 GMT", "version": "v1" }, { "created": "Sat, 26 Jun 2021 15:25:41 GMT", "version": "v2" } ]
2021-06-29
[ [ "Cherchiglia", "A.", "" ], [ "Arias-Perdomo", "D. C.", "" ], [ "Vieira", "A. R.", "" ], [ "Sampaio", "M.", "" ], [ "Hiller", "B.", "" ] ]
We compute the two-loop $\beta$-function of scalar and spinorial quantum electrodynamics as well as pure Yang-Mills and quantum chromodynamics using the background field method in a fully quadridimensional setup using Implicit Regularization (IREG). Moreover, a thorough comparison with dimensional approaches such as conventional dimensional regularization (CDR) and dimensional reduction (DRED) is presented. Subtleties related to Lorentz algebra contractions/symmetric integrations inside divergent integrals as well as renormalisation schemes are carefully discussed within IREG where the renormalisation constants are fully defined as basic divergent integrals to arbitrary loop order. Moreover, we confirm the hypothesis that momentum routing invariance in the loops of Feynman diagrams implemented via setting well-defined surface terms to zero deliver non-abelian gauge invariant amplitudes within IREG just as it has been proven for abelian theories.
1305.5101
Leandro Cieri
Leandro Cieri
NNLO QCD results for diphoton production at the LHC and the Tevatron
8 pages, 3 figures. Contribution to the proceedings of the XXVII Rencontres de Physique de la Vall\'ee d'Aoste. arXiv admin note: substantial text overlap with arXiv:1209.3143, arXiv:1207.3252
null
10.1393/ncc/i2014-11631-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider direct diphoton production in hadron collisions. We compute the next-to-next-to-leading order (NNLO) QCD radiative corrections at the fully-differential level. Our calculation is based on the q_T subtraction formalism and it is implemented in a parton level Monte Carlo program, which allows the user to apply arbitrary kinematical cuts on the final-state photons and the associated jet activity, and to compute the corresponding distributions in the form of bin histograms. We present selected numerical results related to Higgs boson searches and diphoton studies performed at the LHC and the Tevatron, and we show how the NNLO corrections to diphoton production are relevant to understand the main background of the decay channel (H -> gamma gamma) of the Higgs boson H.
[ { "created": "Wed, 22 May 2013 12:22:35 GMT", "version": "v1" } ]
2022-03-02
[ [ "Cieri", "Leandro", "" ] ]
We consider direct diphoton production in hadron collisions. We compute the next-to-next-to-leading order (NNLO) QCD radiative corrections at the fully-differential level. Our calculation is based on the q_T subtraction formalism and it is implemented in a parton level Monte Carlo program, which allows the user to apply arbitrary kinematical cuts on the final-state photons and the associated jet activity, and to compute the corresponding distributions in the form of bin histograms. We present selected numerical results related to Higgs boson searches and diphoton studies performed at the LHC and the Tevatron, and we show how the NNLO corrections to diphoton production are relevant to understand the main background of the decay channel (H -> gamma gamma) of the Higgs boson H.
hep-ph/0310127
Roman Nevzorov
C.Froggatt (Glasgow U.), L.Laperashvili (Moscow, ITEP), R.Nevzorov (Moscow, ITEP), H.B.Nielsen (Bohr Inst.)
Cosmological constant in SUGRA models and the multiple point principle
18 pages, 2 figures, Talk given at Nuclear Physics Department of the Russian Academy of Sciences (RAS) Conference on Physics of Fundamental Interactions, Moscow, Russia, 2-6 Dec 2002; to appear in Phys.Atom.Nucl
Phys.Atom.Nucl.67:582-589,2004; Yad.Fiz.67:601-608,2004
10.1134/1.1690068
null
hep-ph
null
The tiny order of magnitude of the cosmological constant is sought to be explained in a model involving the following ingredients: supersymmetry breaking in N=1 supergravity and the multiple point principle. We demonstrate the viability of this scenario in the minimal SUGRA model.
[ { "created": "Fri, 10 Oct 2003 12:01:07 GMT", "version": "v1" } ]
2011-07-19
[ [ "Froggatt", "C.", "", "Glasgow U." ], [ "Laperashvili", "L.", "", "Moscow, ITEP" ], [ "Nevzorov", "R.", "", "Moscow, ITEP" ], [ "Nielsen", "H. B.", "", "Bohr Inst." ] ]
The tiny order of magnitude of the cosmological constant is sought to be explained in a model involving the following ingredients: supersymmetry breaking in N=1 supergravity and the multiple point principle. We demonstrate the viability of this scenario in the minimal SUGRA model.
hep-ph/0211445
Alexei P. Martynenko
R.N. Faustov (Scientific Council for Cybernetics RAS), A.P. Martynenko (Samara State University)
Nuclear structure corrections in the energy spectra of electronic and muonic deuterium
Talk presented at the Conference "Physics of Fundamental Interactions" of the Nuclear Physics Section of the Physics Department of RAS, ITEP, Moscow, 2-6 December, 2002; 8 pages, REVTEX
Phys.Atom.Nucl. 67 (2004) 457-463; Yad.Fiz. 67 (2004) 477-483
10.1103/PhysRevA.67.052506
Preprint SSU-HEP-02/11
hep-ph
null
The one-loop nuclear structure corrections of order (Z alpha)^5 to the Lamb shift and hyperfine splitting of the deuterium are calculated. The contribution of the deuteron structure effects to the isotope shift (ep)-(ed), (mu p)-(mu d) in the interval (1S - 2S) is obtained on the basis of modern experimental data on the deuteron electromagnetic form factors. The comparison with the similar contributions to the Lamb shift for electronic and muonic hydrogen shows, that the relative contribution due to the nucleus structure increases when passing from the hydrogen to the deuterium.
[ { "created": "Thu, 28 Nov 2002 15:38:47 GMT", "version": "v1" }, { "created": "Fri, 29 Nov 2002 14:38:32 GMT", "version": "v2" }, { "created": "Sat, 14 Dec 2002 12:59:39 GMT", "version": "v3" }, { "created": "Sat, 1 Mar 2003 13:11:54 GMT", "version": "v4" } ]
2009-11-07
[ [ "Faustov", "R. N.", "", "Scientific Council for Cybernetics RAS" ], [ "Martynenko", "A. P.", "", "Samara State University" ] ]
The one-loop nuclear structure corrections of order (Z alpha)^5 to the Lamb shift and hyperfine splitting of the deuterium are calculated. The contribution of the deuteron structure effects to the isotope shift (ep)-(ed), (mu p)-(mu d) in the interval (1S - 2S) is obtained on the basis of modern experimental data on the deuteron electromagnetic form factors. The comparison with the similar contributions to the Lamb shift for electronic and muonic hydrogen shows, that the relative contribution due to the nucleus structure increases when passing from the hydrogen to the deuterium.
hep-ph/0606066
Rishi Sharma
Krishna Rajagopal, Rishi Sharma
The Crystallography of Strange Quark Matter
6 pages, 3 figures. Contribution to the proceedings of Strangeness in Quark Matter 2006, UCLA. Talk given by Rishi Sharma
J.Phys. G32 (2006) S483-S490
10.1088/0954-3899/32/12/S61
MIT-CTP-3753
hep-ph astro-ph cond-mat.supr-con nucl-th
null
Cold three-flavor quark matter at large (but not asymptotically large) densities may exist as a crystalline color superconductor. We explore this possibility by calculating the gap parameter Delta and free energy Omega(Delta) for possible crystal structures within a Ginzburg-Landau approximation, evaluating Omega(Delta) to order Delta^6. We develop a qualitative understanding of what makes a crystal structure stable, and find two structures with particularly large values of Delta and the condensation energy, within a factor of two of those for the CFL phase known to characterize QCD at asymptotically large densities. The robustness of these phases results in their being favored over wide ranges of density and though it also implies that the Ginzburg-Landau approximation is not quantitatively reliable, previous work suggests that it can be trusted for qualitative comparisons between crystal structures. We close with a look ahead at the calculations that remain to be done in order to make contact with observed pulsar glitches and neutron star cooling.
[ { "created": "Tue, 6 Jun 2006 17:45:23 GMT", "version": "v1" } ]
2009-11-11
[ [ "Rajagopal", "Krishna", "" ], [ "Sharma", "Rishi", "" ] ]
Cold three-flavor quark matter at large (but not asymptotically large) densities may exist as a crystalline color superconductor. We explore this possibility by calculating the gap parameter Delta and free energy Omega(Delta) for possible crystal structures within a Ginzburg-Landau approximation, evaluating Omega(Delta) to order Delta^6. We develop a qualitative understanding of what makes a crystal structure stable, and find two structures with particularly large values of Delta and the condensation energy, within a factor of two of those for the CFL phase known to characterize QCD at asymptotically large densities. The robustness of these phases results in their being favored over wide ranges of density and though it also implies that the Ginzburg-Landau approximation is not quantitatively reliable, previous work suggests that it can be trusted for qualitative comparisons between crystal structures. We close with a look ahead at the calculations that remain to be done in order to make contact with observed pulsar glitches and neutron star cooling.
hep-ph/0404069
Mikhail Rogal
J\"urgen G. K\"orner, Zakaria Merebashvili and Mikhail Rogal
Towards a NNLO calculation in hadronic heavy hadron production
5 pages, 2 Postscript figures
Springer Proc.Phys.98:477-480,2005
10.1007/3-540-26798-0_49
null
hep-ph
null
We calculate the Laurent series expansion up to ${\cal O}(\epsilon^2)$ for all scalar one-loop one-, two-, three- and four-point integrals that are needed in the calculation of hadronic heavy flavour production. The Laurent series up to ${\cal O}(\epsilon^2)$ is needed as input to that part of the NNLO corrections to heavy hadron production at hadron colliders where the one-loop integrals appear in the loop-by-loop contributions. The four-point integrals are the most complicated. The ${\cal O}(\epsilon^2)$ expansion of the four-point integrals contains polylogarithms up to $ Li_4$ and the multiple polylogarithms.
[ { "created": "Wed, 7 Apr 2004 11:37:37 GMT", "version": "v1" } ]
2015-06-25
[ [ "Körner", "Jürgen G.", "" ], [ "Merebashvili", "Zakaria", "" ], [ "Rogal", "Mikhail", "" ] ]
We calculate the Laurent series expansion up to ${\cal O}(\epsilon^2)$ for all scalar one-loop one-, two-, three- and four-point integrals that are needed in the calculation of hadronic heavy flavour production. The Laurent series up to ${\cal O}(\epsilon^2)$ is needed as input to that part of the NNLO corrections to heavy hadron production at hadron colliders where the one-loop integrals appear in the loop-by-loop contributions. The four-point integrals are the most complicated. The ${\cal O}(\epsilon^2)$ expansion of the four-point integrals contains polylogarithms up to $ Li_4$ and the multiple polylogarithms.
1705.05944
Alexander Studenikin
Alexande Studenikin
Electromagnetic properties of neutrinos: three new phenomena in neutrino spin oscillations
10 pages, the paper in the proceedings of the 19th International Seminar on High Energy Physics QUARKS-2016 with minor modifications
EPJ Web Conf. 125 (2016) 04018
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In studies of neutrino electromagnetic properties we discuss three very interesting aspects related to neutrino spin oscillations. First we consider neutrino mixing and oscillations in the mass and flavour bases under the influence of a constant magnetic field with nonzero transversal and longitudinal components. Then we discuss the effect of neutrino spin oscillations induced by electroweak interactions of neutrino with moving matter in case there is matter transversal current or polarization. In the final part of the paper we discuss recently developed approach to description of neutrino spin and spin-flavour oscillations in a constant magnetic field that is based on the use of the exact neutrino stationary states in the magnetic field.
[ { "created": "Tue, 16 May 2017 22:22:03 GMT", "version": "v1" } ]
2017-05-18
[ [ "Studenikin", "Alexande", "" ] ]
In studies of neutrino electromagnetic properties we discuss three very interesting aspects related to neutrino spin oscillations. First we consider neutrino mixing and oscillations in the mass and flavour bases under the influence of a constant magnetic field with nonzero transversal and longitudinal components. Then we discuss the effect of neutrino spin oscillations induced by electroweak interactions of neutrino with moving matter in case there is matter transversal current or polarization. In the final part of the paper we discuss recently developed approach to description of neutrino spin and spin-flavour oscillations in a constant magnetic field that is based on the use of the exact neutrino stationary states in the magnetic field.
hep-ph/0212067
Arata Hayashigaki
A. Hayashigaki, K. Suzuki and K. Tanaka
Diffractive \eta_c and \eta_b productions by neutrinos via neutral currents
REVTex4, 4 pages with 3 embedded figures
Phys.Rev. D67 (2003) 093002
10.1103/PhysRevD.67.093002
null
hep-ph nucl-th
null
We report a first theoretical study for neutrino-induced diffractive productions of heavy pseudoscalar mesons, \eta_c and \eta_b, off a nucleon. Based on factorization formalism for exclusive processes, we evaluate the forward diffractive production cross section in perturbative QCD in terms of the light-cone Q\bar{Q} wave functions (WFs) of \eta_{c,b} mesons and the gluon distribution of the nucleon. The light-cone WFs of the \eta_c (\eta_b) meson are constructed to satisfy the spin symmetry relations with those of the J/\psi (\Upsilon) meson. The diffractive \eta_c production is governed by the axial-vector coupling of the longitudinally polarized Z boson to Q\bar{Q} pair, and the resulting \eta_c production rate is larger than the J/\psi one by one order of magnitude. We also discuss the production of bottomonium \eta_b, which shows up for higher beam energy.
[ { "created": "Wed, 4 Dec 2002 17:34:13 GMT", "version": "v1" } ]
2009-11-07
[ [ "Hayashigaki", "A.", "" ], [ "Suzuki", "K.", "" ], [ "Tanaka", "K.", "" ] ]
We report a first theoretical study for neutrino-induced diffractive productions of heavy pseudoscalar mesons, \eta_c and \eta_b, off a nucleon. Based on factorization formalism for exclusive processes, we evaluate the forward diffractive production cross section in perturbative QCD in terms of the light-cone Q\bar{Q} wave functions (WFs) of \eta_{c,b} mesons and the gluon distribution of the nucleon. The light-cone WFs of the \eta_c (\eta_b) meson are constructed to satisfy the spin symmetry relations with those of the J/\psi (\Upsilon) meson. The diffractive \eta_c production is governed by the axial-vector coupling of the longitudinally polarized Z boson to Q\bar{Q} pair, and the resulting \eta_c production rate is larger than the J/\psi one by one order of magnitude. We also discuss the production of bottomonium \eta_b, which shows up for higher beam energy.
hep-ph/0011244
Elizabeth H. Simmons
Elizabeth H. Simmons
Top Physics
Lectures presented at TASI 2000, Flavor Physics for the Millennium, June 4-30, 2000, University of Colorado, Boulder, CO. 44 pages, LaTeX with included style file
null
10.1142/9789812811509_0016
BUHEP-00-23
hep-ph hep-ex
null
The Run I experiments at the Fermilab Tevatron Collider discovered the top quark and provided first measurements of many of its properties. Run II (and eventually the LHC and NLC experiments) promise to extend our knowledge of the top quark significantly. Understanding the top quark's large mass, and indeed the origin of all mass, appears to require physics beyond the Standard Model. Thus, the top quark may have unusual properties accessible to upcoming experiments.
[ { "created": "Mon, 20 Nov 2000 15:38:48 GMT", "version": "v1" }, { "created": "Wed, 6 Dec 2000 19:38:22 GMT", "version": "v2" }, { "created": "Wed, 20 Dec 2000 18:23:45 GMT", "version": "v3" } ]
2017-08-23
[ [ "Simmons", "Elizabeth H.", "" ] ]
The Run I experiments at the Fermilab Tevatron Collider discovered the top quark and provided first measurements of many of its properties. Run II (and eventually the LHC and NLC experiments) promise to extend our knowledge of the top quark significantly. Understanding the top quark's large mass, and indeed the origin of all mass, appears to require physics beyond the Standard Model. Thus, the top quark may have unusual properties accessible to upcoming experiments.
1606.09611
Yuji Hirono
Yuji Hirono, Dmitri E. Kharzeev, Yi Yin
Quantized chiral magnetic current from reconnections of magnetic flux
9 pages, 2 figures; ver2: published version
Phys. Rev. Lett. 117, 172301 (2016)
10.1103/PhysRevLett.117.172301
null
hep-ph cond-mat.str-el hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new mechanism for the chiral magnetic effect that does not require an initial chirality imbalance. The chiral magnetic current is generated by reconnections of magnetic flux that change the magnetic helicity of the system. The resulting current is entirely determined by the change of magnetic helicity, and it is quantized.
[ { "created": "Thu, 30 Jun 2016 18:46:21 GMT", "version": "v1" }, { "created": "Fri, 21 Oct 2016 00:41:15 GMT", "version": "v2" } ]
2016-10-24
[ [ "Hirono", "Yuji", "" ], [ "Kharzeev", "Dmitri E.", "" ], [ "Yin", "Yi", "" ] ]
We introduce a new mechanism for the chiral magnetic effect that does not require an initial chirality imbalance. The chiral magnetic current is generated by reconnections of magnetic flux that change the magnetic helicity of the system. The resulting current is entirely determined by the change of magnetic helicity, and it is quantized.
hep-ph/9409400
null
Brian Mason and Marc Sher
Solar Neutrino Oscillations in the Moon
30 pages, WM-94-114, latex, figures available by fax on request
null
null
null
hep-ph
null
The first three quarters of this paper consists of a pedagogical review of neutrino oscillations, including vacuum oscillations, constant density matter oscillations and variable density matter oscillations. We then address the question of whether MSW solar neutrino oscillations in the moon could be observed during a solar eclipse. For the small angle MSW solution, the effect is unmeasureable; for the large angle solution, we find an enhancement in the rate which can be as large as a factor of two. Since the center of the Sun, as seen from a typical solar neutrino detector (through a transparent Earth) is covered for roughly three hours per decade, a world-wide event rate of a few solar neutrino events per hour might be sufficient to observe this effect. This work constituted the undergraduate senior thesis of Brian Mason, and has been submitted to the American Journal of Physics.
[ { "created": "Fri, 23 Sep 1994 19:35:47 GMT", "version": "v1" } ]
2009-09-25
[ [ "Mason", "Brian", "" ], [ "Sher", "Marc", "" ] ]
The first three quarters of this paper consists of a pedagogical review of neutrino oscillations, including vacuum oscillations, constant density matter oscillations and variable density matter oscillations. We then address the question of whether MSW solar neutrino oscillations in the moon could be observed during a solar eclipse. For the small angle MSW solution, the effect is unmeasureable; for the large angle solution, we find an enhancement in the rate which can be as large as a factor of two. Since the center of the Sun, as seen from a typical solar neutrino detector (through a transparent Earth) is covered for roughly three hours per decade, a world-wide event rate of a few solar neutrino events per hour might be sufficient to observe this effect. This work constituted the undergraduate senior thesis of Brian Mason, and has been submitted to the American Journal of Physics.
hep-ph/0011033
Jiri Hosek
Jiri Hosek
On Superfluid Phases of Cold Deconfined QCD Matter at Moderate Baryon Density
9 pages, talk given at Les Rencontres de Physique de la Vallee d'Aoste, February 27 - March 4, 2000, La Thuile, Italy
null
null
null
hep-ph
null
We present an overview of the arguments which lead to the picture that at low temperatures the QCD matter not far above a critical confinement-deconfinement density exists in one of several distinct superfluid phases exhibiting the quantum behavior on macroscopic scales.
[ { "created": "Thu, 2 Nov 2000 14:19:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hosek", "Jiri", "" ] ]
We present an overview of the arguments which lead to the picture that at low temperatures the QCD matter not far above a critical confinement-deconfinement density exists in one of several distinct superfluid phases exhibiting the quantum behavior on macroscopic scales.
1203.4868
Roman Nikolaevich Lee
Roman N. Lee
DRA method: Powerful tool for the calculation of the loop integrals
6 pages, contribution to ACAT2011 proceedings, Uxbridge, London, September 5-9, 2011, typos are corrected
null
10.1088/1742-6596/368/1/012050
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the method of the calculation of multiloop integrals suggested in Ref.\cite{Lee2010}.
[ { "created": "Thu, 22 Mar 2012 02:06:20 GMT", "version": "v1" }, { "created": "Tue, 27 Mar 2012 05:07:38 GMT", "version": "v2" } ]
2015-06-04
[ [ "Lee", "Roman N.", "" ] ]
We review the method of the calculation of multiloop integrals suggested in Ref.\cite{Lee2010}.
1809.00115
Shunzo Kumano
S. Kumano (KEK/J-PARC)
Theoretical perspective for the future experiments on parton densities
15 pages, LaTeX, 2 style files, 24 figure files, Plenary talk, Proceedings of the XXVI International Workshop on Deep Inelastic Scattering and Related Subjects (DIS2018), April 16-20, 2018, Port Island, Kobe, Japan
null
null
KEK-TH-2061, J-PARC-TH-0132
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I explain the current status of parton-distribution-function (PDF) studies and future experimental prospects on their determinations. First, unpolarized PDFs of the nucleon are introduced as a field of precision QCD physics including higher-order $\alpha_s$ corrections. Second, nuclear PDFs and polarized nucleonic PDFs are discussed. Third, the determination of fragmentation functions is explained. Forth, the three-dimensional (3D) structure functions are discussed in connection with the origin of the nucleon spin and gravitational form factors of hadrons. By the 3D structure functions, gravitational sources and the origin of nucleon mass could be clarified in the microscopic level of quarks and gluons. Furthermore, 3D structure studies of hadrons could be used for clarifying internal structure of exotic hadron candidates, nuclear composition of ultra-high-energy cosmic rays, and color-entanglement phenomena. The PDF field will be developed further along with progress in other fields of science.
[ { "created": "Sat, 1 Sep 2018 05:21:43 GMT", "version": "v1" }, { "created": "Fri, 14 Sep 2018 10:36:48 GMT", "version": "v2" } ]
2018-09-17
[ [ "Kumano", "S.", "", "KEK/J-PARC" ] ]
I explain the current status of parton-distribution-function (PDF) studies and future experimental prospects on their determinations. First, unpolarized PDFs of the nucleon are introduced as a field of precision QCD physics including higher-order $\alpha_s$ corrections. Second, nuclear PDFs and polarized nucleonic PDFs are discussed. Third, the determination of fragmentation functions is explained. Forth, the three-dimensional (3D) structure functions are discussed in connection with the origin of the nucleon spin and gravitational form factors of hadrons. By the 3D structure functions, gravitational sources and the origin of nucleon mass could be clarified in the microscopic level of quarks and gluons. Furthermore, 3D structure studies of hadrons could be used for clarifying internal structure of exotic hadron candidates, nuclear composition of ultra-high-energy cosmic rays, and color-entanglement phenomena. The PDF field will be developed further along with progress in other fields of science.
2006.07950
Kirill Tuchin
Kirill Tuchin
Anomalous scattering and transport in chiral matter
14 pages, v2: improved presentation, the role of the chiral instability discussed, typos fixed
null
10.1016/j.physletb.2020.135680
null
hep-ph cond-mat.mes-hall nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Chiral anomaly modifies the scattering processes in chiral systems which can be computed using the Maxwell-Chern-Simons theory that couples electrodynamics to the pseudoscalar field $\theta$ describing the topological charge induced be external sources. Assuming slow variation of the topological charge density, the fermion scattering cross section is computed in the Born approximation and is found to have a resonance at the scattering angles proportional to the chiral conductivity. As a result, the transport coefficients are suppressed at high temperatures. The anisotropy of the cross section arises due to the spatial variation of the topological charge; its effect on the electrical conductivity is discussed.
[ { "created": "Sun, 14 Jun 2020 16:37:55 GMT", "version": "v1" }, { "created": "Tue, 4 Aug 2020 21:09:23 GMT", "version": "v2" } ]
2020-08-12
[ [ "Tuchin", "Kirill", "" ] ]
Chiral anomaly modifies the scattering processes in chiral systems which can be computed using the Maxwell-Chern-Simons theory that couples electrodynamics to the pseudoscalar field $\theta$ describing the topological charge induced be external sources. Assuming slow variation of the topological charge density, the fermion scattering cross section is computed in the Born approximation and is found to have a resonance at the scattering angles proportional to the chiral conductivity. As a result, the transport coefficients are suppressed at high temperatures. The anisotropy of the cross section arises due to the spatial variation of the topological charge; its effect on the electrical conductivity is discussed.
1512.06828
Martin Bauer
Martin Bauer and Matthias Neubert
Flavor Anomalies, the Diphoton Excess and a Dark Matter Candidate
5 pages, 5 figures; Corrected typos, Plot edited, discussion extended
Phys. Rev. D 93, 115030 (2016)
10.1103/PhysRevD.93.115030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the diphoton excess recently reported by ATLAS and CMS can be explained, along with several anomalies seen in the flavor sector, in models where a Standard-Model singlet scalar resonance with mass $M \approx 750$ GeV is produced in gluon fusion via loops containing a scalar color- triplet leptoquark $\phi$. For a leptoquark mass $M_\phi \lesssim$ 1 TeV, the production cross section is naturally in the 10 fb range. A large $S \to \gamma \gamma$ branching ratio can be obtained by coupling the scalar S to new color-singlet fermions $\chi$ with electroweak scale masses, which can be part of an $SU(2)_L$ multiplet, whose neutral component has the right mass and quantum numbers to be a dark matter candidate. Our model reveals a connection between flavor anomalies, the nature of dark matter and a new scalar, which acts as a mediator to the dark sector. The loop-mediated decay $S \to \tau^+\tau^-$ could be a striking signature of this model.
[ { "created": "Mon, 21 Dec 2015 20:53:21 GMT", "version": "v1" }, { "created": "Sat, 23 Jan 2016 09:41:48 GMT", "version": "v2" }, { "created": "Tue, 28 Jun 2016 21:20:27 GMT", "version": "v3" } ]
2016-07-06
[ [ "Bauer", "Martin", "" ], [ "Neubert", "Matthias", "" ] ]
We argue that the diphoton excess recently reported by ATLAS and CMS can be explained, along with several anomalies seen in the flavor sector, in models where a Standard-Model singlet scalar resonance with mass $M \approx 750$ GeV is produced in gluon fusion via loops containing a scalar color- triplet leptoquark $\phi$. For a leptoquark mass $M_\phi \lesssim$ 1 TeV, the production cross section is naturally in the 10 fb range. A large $S \to \gamma \gamma$ branching ratio can be obtained by coupling the scalar S to new color-singlet fermions $\chi$ with electroweak scale masses, which can be part of an $SU(2)_L$ multiplet, whose neutral component has the right mass and quantum numbers to be a dark matter candidate. Our model reveals a connection between flavor anomalies, the nature of dark matter and a new scalar, which acts as a mediator to the dark sector. The loop-mediated decay $S \to \tau^+\tau^-$ could be a striking signature of this model.
hep-ph/9208235
null
Y. Achiman and A. Lukas
E6 GUT and Large Neutrino Mixing
10 pages, 7 Figures (not included), WUB 92-20, TUM-TH-149/92, MPI-Ph/92-69
Phys.Lett. B296 (1992) 127-131
10.1016/0370-2693(92)90813-J
null
hep-ph
null
All experimental results concerning possible neutrino oscillations are naturally and simultaneously accounted for in an $E_6$ GUT model. The fermionic mass matrices are dictated by the symmetry breaking and specific radiative corrections and not by the use of ``Ans\"atze'' or discrete symmetries.
[ { "created": "Thu, 20 Aug 1992 15:38:18 GMT", "version": "v1" } ]
2009-10-22
[ [ "Achiman", "Y.", "" ], [ "Lukas", "A.", "" ] ]
All experimental results concerning possible neutrino oscillations are naturally and simultaneously accounted for in an $E_6$ GUT model. The fermionic mass matrices are dictated by the symmetry breaking and specific radiative corrections and not by the use of ``Ans\"atze'' or discrete symmetries.
hep-ph/0412286
Johan Alwall
Johan Alwall
Sea Quark Asymmetries in the Nucleon - A physical model for parton distributions in hadrons
6 pages, 4 figures. Talk given at HSQCD, St. Petersburg, Russia, May 2004
null
null
null
hep-ph
null
A physical model for parton densities in hadrons, based on Gaussian momentum fluctuations of partons and hadronic baryon-meson fluctuations, is presented. The model has previously been shown to describe proton structure function data, and is now applied to sea quark asymmetries and shown to describe the dbar-ubar asymmetry of the proton. By considering fluctuations involving strange quarks, the model gives an asymmetry between the momentum distributions of s and sbar, which would reduce the significance of the NuTeV anomaly.
[ { "created": "Mon, 20 Dec 2004 13:26:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Alwall", "Johan", "" ] ]
A physical model for parton densities in hadrons, based on Gaussian momentum fluctuations of partons and hadronic baryon-meson fluctuations, is presented. The model has previously been shown to describe proton structure function data, and is now applied to sea quark asymmetries and shown to describe the dbar-ubar asymmetry of the proton. By considering fluctuations involving strange quarks, the model gives an asymmetry between the momentum distributions of s and sbar, which would reduce the significance of the NuTeV anomaly.
hep-ph/0301163
D. R. T. Jones
I. Jack and D.R.T. Jones
Yukawa Textures and Anomaly Mediated Supersymmetry Breaking
33 pages, TeX, Uses Harvmac (big) and epsf. Added references and minor changes and corrections. Improved texture discussion
Nucl.Phys.B662:63-88,2003
10.1016/S0550-3213(03)00310-9
LTH 568
hep-ph
null
We present a detailed analysis of how a mixed-anomaly-free U(1) symmetry can be used to both resolve the slepton mass problem associated with Anomaly Mediated Supersymmetry Breaking and generate the fermion mass hierarchy via the Froggatt-Nielsen mechanism. Flavour changing neutral currents problems are evaded by a specific form of the Yukawa textures.
[ { "created": "Mon, 20 Jan 2003 17:27:38 GMT", "version": "v1" }, { "created": "Wed, 29 Jan 2003 17:30:50 GMT", "version": "v2" }, { "created": "Tue, 25 Mar 2003 15:03:30 GMT", "version": "v3" } ]
2014-11-17
[ [ "Jack", "I.", "" ], [ "Jones", "D. R. T.", "" ] ]
We present a detailed analysis of how a mixed-anomaly-free U(1) symmetry can be used to both resolve the slepton mass problem associated with Anomaly Mediated Supersymmetry Breaking and generate the fermion mass hierarchy via the Froggatt-Nielsen mechanism. Flavour changing neutral currents problems are evaded by a specific form of the Yukawa textures.
1505.05516
Juan Gonzalez-Fraile
Tyler Corbett, Oscar J. P. Eboli, Dorival Goncalves, J. Gonzalez-Fraile, Tilman Plehn, Michael Rauch
The Higgs Legacy of the LHC Run I
29 pages, 15 figures
null
null
IPPP/15/32, DCPT/15/64
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on Run I data we present a comprehensive analysis of Higgs couplings. For the first time this SFitter analysis includes independent tests of the Higgs-gluon and top Yukawa couplings, Higgs decays to invisible particles, and off-shell Higgs measurements. The observed Higgs boson is fully consistent with the Standard Model, both in terms of coupling modifications and effective field theory. Based only on Higgs total rates the results using both approaches are essentially equivalent, with the exception of strong correlations in the parameter space induced by effective operators. These correlations can be controlled through additional experimental input, namely kinematic distributions. Including kinematic distributions the typical Run I reach for weakly interacting new physics now reaches 300 to 500 GeV.
[ { "created": "Wed, 20 May 2015 20:01:17 GMT", "version": "v1" } ]
2015-05-27
[ [ "Corbett", "Tyler", "" ], [ "Eboli", "Oscar J. P.", "" ], [ "Goncalves", "Dorival", "" ], [ "Gonzalez-Fraile", "J.", "" ], [ "Plehn", "Tilman", "" ], [ "Rauch", "Michael", "" ] ]
Based on Run I data we present a comprehensive analysis of Higgs couplings. For the first time this SFitter analysis includes independent tests of the Higgs-gluon and top Yukawa couplings, Higgs decays to invisible particles, and off-shell Higgs measurements. The observed Higgs boson is fully consistent with the Standard Model, both in terms of coupling modifications and effective field theory. Based only on Higgs total rates the results using both approaches are essentially equivalent, with the exception of strong correlations in the parameter space induced by effective operators. These correlations can be controlled through additional experimental input, namely kinematic distributions. Including kinematic distributions the typical Run I reach for weakly interacting new physics now reaches 300 to 500 GeV.
hep-ph/0304197
Mircea Beciu
M. I. Beciu
Degenerate Rindler Vacuum
11 pages, no figures
null
null
null
hep-ph gr-qc
null
We combine the creation and annihilation operators of a scalar field in Minkowski spacetime to obtain the generators of the SU(1,1). We show that the transformation between Minkowski and Rindler vacua can be represented by (pseudo)rotation in the space of the SU(1,1) group. The root of this fact originates from the coordinate transformation between Minkowski and Rindler manifolds that can also be represented as a (pseudo)rotation in SU(1,1) group. The group structure reveals that an independent (pseudo)rotation in the group space must exist which leads to a new vacuum state, independent Rindler vacuum. The newly defined state shares many of the properties of the Rindler vacuum and, in particular, the theorem of thermalization remains valid for it.
[ { "created": "Mon, 21 Apr 2003 14:48:39 GMT", "version": "v1" } ]
2009-09-29
[ [ "Beciu", "M. I.", "" ] ]
We combine the creation and annihilation operators of a scalar field in Minkowski spacetime to obtain the generators of the SU(1,1). We show that the transformation between Minkowski and Rindler vacua can be represented by (pseudo)rotation in the space of the SU(1,1) group. The root of this fact originates from the coordinate transformation between Minkowski and Rindler manifolds that can also be represented as a (pseudo)rotation in SU(1,1) group. The group structure reveals that an independent (pseudo)rotation in the group space must exist which leads to a new vacuum state, independent Rindler vacuum. The newly defined state shares many of the properties of the Rindler vacuum and, in particular, the theorem of thermalization remains valid for it.
1508.01522
Salvator Lombardo
Csaba Csaki, Eric Kuflik, Salvator Lombardo, Oren Slone
Searching for Displaced Higgs Decays
10 pages, 12 figures, v3: displaced jet trigger corrected
Phys. Rev. D 92, 073008 (2015)
10.1103/PhysRevD.92.073008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a simplified model of the SM Higgs boson decaying to a degenerate pair of scalars which travel a macroscopic distance before decaying to SM particles. This is the leading signal for many well-motivated solutions to the hierarchy problem that do not propose additional light colored particles. Bounds for displaced Higgs decays below $10$ cm are found by recasting existing tracker searches from Run I. New tracker search strategies, sensitive to the characteristics of these models and similar decays, are proposed with sensitivities projected for Run II at $\sqrt{s} = 13 $ TeV. With 20 fb$^{-1}$ of data, we find that Higgs branching ratios down to $7 \times 10^{-4}$ can be probed for centimeter decay lengths.
[ { "created": "Thu, 6 Aug 2015 20:07:52 GMT", "version": "v1" }, { "created": "Wed, 26 Aug 2015 19:55:38 GMT", "version": "v2" }, { "created": "Wed, 25 Nov 2015 22:09:08 GMT", "version": "v3" } ]
2015-11-30
[ [ "Csaki", "Csaba", "" ], [ "Kuflik", "Eric", "" ], [ "Lombardo", "Salvator", "" ], [ "Slone", "Oren", "" ] ]
We study a simplified model of the SM Higgs boson decaying to a degenerate pair of scalars which travel a macroscopic distance before decaying to SM particles. This is the leading signal for many well-motivated solutions to the hierarchy problem that do not propose additional light colored particles. Bounds for displaced Higgs decays below $10$ cm are found by recasting existing tracker searches from Run I. New tracker search strategies, sensitive to the characteristics of these models and similar decays, are proposed with sensitivities projected for Run II at $\sqrt{s} = 13 $ TeV. With 20 fb$^{-1}$ of data, we find that Higgs branching ratios down to $7 \times 10^{-4}$ can be probed for centimeter decay lengths.
hep-ph/9207275
null
M. S. Berger
Test of an Equivalence Theorem at One-Loop
8 pages + 4 figures available on request, MAD/PH/712
null
null
null
hep-ph
null
We show that the equivalence theorem approximating one-loop gauge sector diagrams by including only Goldstone bosons in the loop gives a remarkably poor approximation to the amplitude for the decay $H\rightarrow \gamma \gamma $ and for the process $\gamma \gamma \rightarrow HH$. At one loop, large logarithms can arise that evade power counting arguments.
[ { "created": "Thu, 30 Jul 1992 22:34:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Berger", "M. S.", "" ] ]
We show that the equivalence theorem approximating one-loop gauge sector diagrams by including only Goldstone bosons in the loop gives a remarkably poor approximation to the amplitude for the decay $H\rightarrow \gamma \gamma $ and for the process $\gamma \gamma \rightarrow HH$. At one loop, large logarithms can arise that evade power counting arguments.
2104.06101
Ahmed Gamal
Hesham Mansour, Ahmed Gamal
Meson Spectra using Nikiforov-Uvarov Method
20 pages, 7 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
There are many phenomenological potentials using different techniques to describe the spectroscopy of the quarkonium systems like charmonium, bottomonium, Bc meson systems. In the present work, we choose a phenomenological potential (linear, Yukawa, and harmonic potentials) in the framework of the nonrelativistic Schrodinger equation with relativistic corrections using the Nikiforov-Uvarov (NU) method. We obtained the eigenfunction and eigenvalue comparing the results with the available experimental data. The results are in good agreement with the available experimental data.
[ { "created": "Tue, 13 Apr 2021 11:08:13 GMT", "version": "v1" } ]
2021-04-14
[ [ "Mansour", "Hesham", "" ], [ "Gamal", "Ahmed", "" ] ]
There are many phenomenological potentials using different techniques to describe the spectroscopy of the quarkonium systems like charmonium, bottomonium, Bc meson systems. In the present work, we choose a phenomenological potential (linear, Yukawa, and harmonic potentials) in the framework of the nonrelativistic Schrodinger equation with relativistic corrections using the Nikiforov-Uvarov (NU) method. We obtained the eigenfunction and eigenvalue comparing the results with the available experimental data. The results are in good agreement with the available experimental data.
1211.4008
Maxim Perelstein
Yoonseok John Chae and Maxim Perelstein
Dark Matter Search at a Linear Collider: Effective Operator Approach
15 pages, 5 figures
null
10.1007/JHEP05(2013)138
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experiments at electron-positron colliders can search for dark matter particle pair-production in association with a photon. We estimate the sensitivity of this search at the proposed International Linear Collider (ILC), under a variety of run scenarios. We employ the effective operator formalism to provide a quasi-model-independent theoretical description of the signal, and present the reach of the ILC in terms of the scale \Lambda suppressing the dark matter-electron coupling operator. We find that at the 250 GeV center-of-mass energy, the ILC can probe \Lambda up to 1-1.2 TeV, a factor of 2.5-3 above the best current bounds from LEP-2. With 1 TeV energy and polarized beams, the reach can be extended to 3-4 TeV. The ILC can discover this signature even if annihilation to electrons provides only a small fraction of the total dark matter annihilation rate in the early universe. We also argue that large regions of parameter space allowed by current LHC and direct detection bounds will be accessible at the ILC.
[ { "created": "Fri, 16 Nov 2012 20:14:45 GMT", "version": "v1" } ]
2015-06-12
[ [ "Chae", "Yoonseok John", "" ], [ "Perelstein", "Maxim", "" ] ]
Experiments at electron-positron colliders can search for dark matter particle pair-production in association with a photon. We estimate the sensitivity of this search at the proposed International Linear Collider (ILC), under a variety of run scenarios. We employ the effective operator formalism to provide a quasi-model-independent theoretical description of the signal, and present the reach of the ILC in terms of the scale \Lambda suppressing the dark matter-electron coupling operator. We find that at the 250 GeV center-of-mass energy, the ILC can probe \Lambda up to 1-1.2 TeV, a factor of 2.5-3 above the best current bounds from LEP-2. With 1 TeV energy and polarized beams, the reach can be extended to 3-4 TeV. The ILC can discover this signature even if annihilation to electrons provides only a small fraction of the total dark matter annihilation rate in the early universe. We also argue that large regions of parameter space allowed by current LHC and direct detection bounds will be accessible at the ILC.
hep-ph/0206288
Carsten Vogt
M. Diehl, P. Kroll and C. Vogt
Two-Photon Annihilation into Baryon-Antibaryon Pairs
20 pages latex, 4 figures. v2: minor clarifications, references updated
Eur.Phys.J.C26:567-577,2003
10.1140/epjc/s2002-01075-4
WU B 02-06, NORDITA-2002-15 HE
hep-ph
null
We study the handbag contribution to two-photon annihilation into baryon-antibaryon pairs at large energy and momentum transfer. We derive factorization of the process amplitude into a hard gamma gamma -> q qbar subprocess and form factors describing the soft q qbar -> B Bbar transition, assuming that the process is dominated by configurations where the (anti)quark approximately carries the full momentum of the (anti)baryon. The form factors represent moments of time-like generalized parton distributions, so-called B Bbar distribution amplitudes. A characteristic feature of the handbag mechanism is the absence of isospin-two components in the final state, which in combination with flavor symmetry provides relations among the form factors for the members of the lowest-lying baryon octet. Assuming dominance of the handbag contribution, we can describe current experimental data with form factors of plausible size, and predict the cross sections of presently unmeasured B Bbar channels.
[ { "created": "Thu, 27 Jun 2002 16:54:10 GMT", "version": "v1" }, { "created": "Wed, 16 Oct 2002 14:16:24 GMT", "version": "v2" } ]
2011-09-13
[ [ "Diehl", "M.", "" ], [ "Kroll", "P.", "" ], [ "Vogt", "C.", "" ] ]
We study the handbag contribution to two-photon annihilation into baryon-antibaryon pairs at large energy and momentum transfer. We derive factorization of the process amplitude into a hard gamma gamma -> q qbar subprocess and form factors describing the soft q qbar -> B Bbar transition, assuming that the process is dominated by configurations where the (anti)quark approximately carries the full momentum of the (anti)baryon. The form factors represent moments of time-like generalized parton distributions, so-called B Bbar distribution amplitudes. A characteristic feature of the handbag mechanism is the absence of isospin-two components in the final state, which in combination with flavor symmetry provides relations among the form factors for the members of the lowest-lying baryon octet. Assuming dominance of the handbag contribution, we can describe current experimental data with form factors of plausible size, and predict the cross sections of presently unmeasured B Bbar channels.
hep-ph/0205069
Michael Klasen
S. Albino, M. Klasen (Hamburg), S. Soldner-Rembold (Fermilab)
Strong Coupling Constant from the Photon Structure Function
11 pages, 2 tables, 2 figures. Version accepted for publication by Phys. Rev. Lett
Phys.Rev.Lett. 89 (2002) 122004
10.1103/PhysRevLett.89.122004
DESY 02-052, FERMILAB-Pub-02/071-E
hep-ph hep-ex
null
We extract the value of the strong coupling constant alpha_s from a single-parameter pointlike fit to the photon structure function F_2^gamma at large x and Q^2 and from a first five-parameter full (pointlike and hadronic) fit to the complete F_2^gamma data set taken at PETRA, TRISTAN, and LEP. In next-to-leading order and the MSbar renormalization and factorization schemes, we obtain alpha_s(m_Z)=0.1183 +/- 0.0050(exp.)^+0.0029_-0.0028(theor.) [pointlike] and alpha_s(m_Z)=0.1198 +/- 0.0028(exp.)^+0.0034_-0.0046(theor.) [pointlike and hadronic]. We demonstrate that the data taken at LEP have reduced the experimental error by about a factor of two, so that a competitive determination of alpha_s from F_2^gamma is now possible.
[ { "created": "Wed, 8 May 2002 06:26:25 GMT", "version": "v1" }, { "created": "Mon, 29 Jul 2002 06:38:28 GMT", "version": "v2" } ]
2009-11-07
[ [ "Albino", "S.", "", "Hamburg" ], [ "Klasen", "M.", "", "Hamburg" ], [ "Soldner-Rembold", "S.", "", "Fermilab" ] ]
We extract the value of the strong coupling constant alpha_s from a single-parameter pointlike fit to the photon structure function F_2^gamma at large x and Q^2 and from a first five-parameter full (pointlike and hadronic) fit to the complete F_2^gamma data set taken at PETRA, TRISTAN, and LEP. In next-to-leading order and the MSbar renormalization and factorization schemes, we obtain alpha_s(m_Z)=0.1183 +/- 0.0050(exp.)^+0.0029_-0.0028(theor.) [pointlike] and alpha_s(m_Z)=0.1198 +/- 0.0028(exp.)^+0.0034_-0.0046(theor.) [pointlike and hadronic]. We demonstrate that the data taken at LEP have reduced the experimental error by about a factor of two, so that a competitive determination of alpha_s from F_2^gamma is now possible.
1205.1996
Kamakshya Modak
Kamakshya Prasad Modak, Debasish Majumdar
Gamma Ray and Neutrino Flux from Annihilation of Neutralino Dark Matter at Galactic Halo Region in mAMSB Model
34 pages LaTeX, 36 postscript figures; Text and figures modified, new figures added; version published in J. Phys. G
J. Phys. G: Nucl. Part. Phys. 40 (2013) 075201
10.1088/0954-3899/40/7/075201
SINP-APC-12/3
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the lightest supersymmetric particle (LSP), neutralino in minimal anomaly mediated supersymmetry breaking model (mAMSB) to be a possible candidate for weakly interacting massive particles (WIMP) or cold dark matter and investigate its direct and indirect detections. The theoretically allowed supersymmetric parametric space for such a model along with the recent bounds from LHC is constrained by the WMAP results for relic densities. The spin independent and spin dependent scattering cross sections for dark matter off nucleon are thus constrained from the WMAP results. They are found to be within the allowed regions of different ongoing direct detection experiments. The annihilation of such dark matter candidates at the galactic centre produce different standard model particles such as gamma rays, neutrinos etc. In this work, we calculate the possible fluxes of these $\gamma$-rays and neutrinos coming from the direction of the galactic centre (and its neighbourhood) at terrestrial or satellite borne detectors. The calcutated $\gamma$-ray flux is compared with the observational results of HESS experiment. The neutrino flux of different flavours from the galactic centre and at different locations away from the galactic centre produced by WIMP annihilation in this model are also obtained for four types of galactic dark matter halo profiles. The detection prospects of such $\nu_\mu$ coming from the direction of the galactic centre at the ANTARES under sea detector are discussed in terms of muon signal yield from these muon neutrinos. Both the gamma and neutrino signals are estimated for four different dark matter halo profiles.
[ { "created": "Wed, 9 May 2012 14:32:42 GMT", "version": "v1" }, { "created": "Thu, 27 Jun 2013 13:32:59 GMT", "version": "v2" } ]
2013-06-28
[ [ "Modak", "Kamakshya Prasad", "" ], [ "Majumdar", "Debasish", "" ] ]
We consider the lightest supersymmetric particle (LSP), neutralino in minimal anomaly mediated supersymmetry breaking model (mAMSB) to be a possible candidate for weakly interacting massive particles (WIMP) or cold dark matter and investigate its direct and indirect detections. The theoretically allowed supersymmetric parametric space for such a model along with the recent bounds from LHC is constrained by the WMAP results for relic densities. The spin independent and spin dependent scattering cross sections for dark matter off nucleon are thus constrained from the WMAP results. They are found to be within the allowed regions of different ongoing direct detection experiments. The annihilation of such dark matter candidates at the galactic centre produce different standard model particles such as gamma rays, neutrinos etc. In this work, we calculate the possible fluxes of these $\gamma$-rays and neutrinos coming from the direction of the galactic centre (and its neighbourhood) at terrestrial or satellite borne detectors. The calcutated $\gamma$-ray flux is compared with the observational results of HESS experiment. The neutrino flux of different flavours from the galactic centre and at different locations away from the galactic centre produced by WIMP annihilation in this model are also obtained for four types of galactic dark matter halo profiles. The detection prospects of such $\nu_\mu$ coming from the direction of the galactic centre at the ANTARES under sea detector are discussed in terms of muon signal yield from these muon neutrinos. Both the gamma and neutrino signals are estimated for four different dark matter halo profiles.
hep-ph/9903233
Peter Lichard
Peter Lichard (Department of Physics and Astronomy, University of Pittsburgh, USA and Institute of Physics, Silesian University, Czech Republic)
Relations between the K_{l3} and tau --> K pi nu_tau decays
14 pages, RevTeX, epsf.sty, 3 embedded figures
Phys.Rev. D60 (1999) 093012
10.1103/PhysRevD.60.093012
null
hep-ph
null
We investigate the relations between the K_{l3} and tau --> K pi nu_tau decays using the meson dominance approach. First, the experimental branching fractions (BF) for K^-_{e3} and K^0_{e3} are used to fix two normalization constants (isospin invariance is not assumed). Then, the BF of tau^- --> K^*(892)^- nu_tau is calculated in agreement with experiment. We further argue that the nonzero value of the slope parameter lambda_0 of the K^-_{mu3} and K^0_{mu3} form factors f_0(t) implies the existence of the tau^- --> K_0^*(1430)^- nu_tau decay. We calculate its BF, together with BF's of the K^-_{mu3}, K^0_{mu3}, tau- --> K^- pi^0 nu_tau, and tau- --> antiK^0 pi^0 nu_tau decays, as a function of the lambda_0 parameter. At some value of lambda_0, different for charged and neutral kaons, calculated BF's seem to match existing data and a prediction is obtained for the tau^- --> K pi nu decays going through the K_0^*(1430)^- resonance.
[ { "created": "Tue, 2 Mar 1999 19:19:55 GMT", "version": "v1" } ]
2009-10-31
[ [ "Lichard", "Peter", "", "Department of Physics and Astronomy, University of\n Pittsburgh, USA and Institute of Physics, Silesian University, Czech\n Republic" ] ]
We investigate the relations between the K_{l3} and tau --> K pi nu_tau decays using the meson dominance approach. First, the experimental branching fractions (BF) for K^-_{e3} and K^0_{e3} are used to fix two normalization constants (isospin invariance is not assumed). Then, the BF of tau^- --> K^*(892)^- nu_tau is calculated in agreement with experiment. We further argue that the nonzero value of the slope parameter lambda_0 of the K^-_{mu3} and K^0_{mu3} form factors f_0(t) implies the existence of the tau^- --> K_0^*(1430)^- nu_tau decay. We calculate its BF, together with BF's of the K^-_{mu3}, K^0_{mu3}, tau- --> K^- pi^0 nu_tau, and tau- --> antiK^0 pi^0 nu_tau decays, as a function of the lambda_0 parameter. At some value of lambda_0, different for charged and neutral kaons, calculated BF's seem to match existing data and a prediction is obtained for the tau^- --> K pi nu decays going through the K_0^*(1430)^- resonance.
0706.3438
Antoni Szczurek
A. Szczurek, A. Rybarska, G. Slipek
Dijet correlations in $pp$ collisions at RHIC
11 pages, 23 figures, a talk presented at International Workshop on High-pT physics at LHC, Jyvaskyla, Finland, March 23-27 2007
null
null
null
hep-ph
null
We compare results of $k_t$-factorization approach and next-to-leading order collinear-factorization approach for dijet correlations in proton-proton collisions at RHIC energies. We discuss correlations in azimuthal angle as well as correlations in two-dimensional space of transverse momenta of two jets. Some $k_t$-factorization subprocesses are included for the first time in the literature. Different unintegrated gluon/parton distributions are used in the $k_t$-factorization approach. The results depend on UGDF/UPDF used. Limitations due to leading jet condition are discussed.
[ { "created": "Sat, 23 Jun 2007 09:44:36 GMT", "version": "v1" } ]
2009-04-16
[ [ "Szczurek", "A.", "" ], [ "Rybarska", "A.", "" ], [ "Slipek", "G.", "" ] ]
We compare results of $k_t$-factorization approach and next-to-leading order collinear-factorization approach for dijet correlations in proton-proton collisions at RHIC energies. We discuss correlations in azimuthal angle as well as correlations in two-dimensional space of transverse momenta of two jets. Some $k_t$-factorization subprocesses are included for the first time in the literature. Different unintegrated gluon/parton distributions are used in the $k_t$-factorization approach. The results depend on UGDF/UPDF used. Limitations due to leading jet condition are discussed.
1410.3276
Mainak Chakraborty
Mainak Chakraborty, H. Zeen Devi, Ambar Ghosal
Scaling ansatz with texture zeros in linear seesaw
18 pages, 10 tables, 1 figure, Accepted for publication in Physics Letters B
null
10.1016/j.physletb.2014.12.038
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate scaling ansatz with texture zeros within the framework of linear seesaw mechanism. In this variant of seesaw mechanism a simplified expression of effective neutrino mass matrix $m_\nu$ containing two Dirac type matrices ($m_D$ and $m_{DS}$) and one Majorana type matrix ($m_{RS}$) is obtained by virtue of neglecting the global $U(1)_L$ symmetry breaking term in the mass term of the Lagrangian. Along with the charged lepton mass matrix, the matrix $m_{RS}$ too, is chosen in a diagonal basis whereas a scaling relation is incorporated in $m_D$ and $m_{DS}$ with different scale factors. Our goal in this work is to achieve a completely phenomenologically acceptable $m_\nu$ generated by combinations of $m_D$ and $m_{DS}$ containing least number of independent parameters or maximum number of zeros. At the end of the numerical analysis it is found that number of zeros in any of the constituent Dirac type matrices ($m_D$ and $m_{DS}$) of $m_\nu$ cannot be greater than six in order to meet the phenomenological requirements. The hierarchy obtained here is normal and also the values of the two parameters sum mass ($\sum m_i$) and $|m_{\nu_{ee}}|$ are below the present experimental lower limit.
[ { "created": "Mon, 13 Oct 2014 12:19:13 GMT", "version": "v1" }, { "created": "Tue, 6 Jan 2015 08:16:12 GMT", "version": "v2" } ]
2018-05-09
[ [ "Chakraborty", "Mainak", "" ], [ "Devi", "H. Zeen", "" ], [ "Ghosal", "Ambar", "" ] ]
We investigate scaling ansatz with texture zeros within the framework of linear seesaw mechanism. In this variant of seesaw mechanism a simplified expression of effective neutrino mass matrix $m_\nu$ containing two Dirac type matrices ($m_D$ and $m_{DS}$) and one Majorana type matrix ($m_{RS}$) is obtained by virtue of neglecting the global $U(1)_L$ symmetry breaking term in the mass term of the Lagrangian. Along with the charged lepton mass matrix, the matrix $m_{RS}$ too, is chosen in a diagonal basis whereas a scaling relation is incorporated in $m_D$ and $m_{DS}$ with different scale factors. Our goal in this work is to achieve a completely phenomenologically acceptable $m_\nu$ generated by combinations of $m_D$ and $m_{DS}$ containing least number of independent parameters or maximum number of zeros. At the end of the numerical analysis it is found that number of zeros in any of the constituent Dirac type matrices ($m_D$ and $m_{DS}$) of $m_\nu$ cannot be greater than six in order to meet the phenomenological requirements. The hierarchy obtained here is normal and also the values of the two parameters sum mass ($\sum m_i$) and $|m_{\nu_{ee}}|$ are below the present experimental lower limit.
2107.13882
Zhou Rui
Meng-Kun Jia, Chao-Qi Zhang, Jia-Ming Li, and Zhou Rui
$S$-wave contributions to the $B_{(s)}\rightarrow \chi_{c1} (\pi\pi,K\pi,KK)$ decays
17 pages, 5 figures
Phys. Rev. D 104, 073001 (2021)
10.1103/PhysRevD.104.073001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We make a detailed study of the three-body decays $B_{(s)}\rightarrow \chi_{c1} hh'$, where $h^{(')}$ is either a pion or kaon, by taking into account the $S$-wave states in the $hh'$ invariant mass distribution within the perturbative QCD approach. The two meson distribution amplitudes (DAs) are introduced to capture the strong interaction related to the production of the $hh'$ system. We calculate the branching ratios for the $S$-wave components and observe large values of order $10^{-4}$ for some Cabibbo-favored decays, which are accessible to the LHCb and Belle II experiments. The obtained branching ratio $\mathcal{B}(B\rightarrow \chi_{c1}K^*_{0}(1430)(\rightarrow K^+\pi^-))=(5.1^{+0.6}_{-0.8})\times 10^{-5}$ consistent with the data from Belle within errors. Moreover, we also predict the differential distributions in the $hh'$ invariant mass for the decays under consideration, which await the future experimental test. In addition, the corresponding $\chi_{c1}(2P)$ channels are also investigated, which are helpful to clarify the nature of the $X(3872)$ state.
[ { "created": "Thu, 29 Jul 2021 10:34:30 GMT", "version": "v1" }, { "created": "Wed, 6 Oct 2021 00:39:38 GMT", "version": "v2" } ]
2021-10-13
[ [ "Jia", "Meng-Kun", "" ], [ "Zhang", "Chao-Qi", "" ], [ "Li", "Jia-Ming", "" ], [ "Rui", "Zhou", "" ] ]
We make a detailed study of the three-body decays $B_{(s)}\rightarrow \chi_{c1} hh'$, where $h^{(')}$ is either a pion or kaon, by taking into account the $S$-wave states in the $hh'$ invariant mass distribution within the perturbative QCD approach. The two meson distribution amplitudes (DAs) are introduced to capture the strong interaction related to the production of the $hh'$ system. We calculate the branching ratios for the $S$-wave components and observe large values of order $10^{-4}$ for some Cabibbo-favored decays, which are accessible to the LHCb and Belle II experiments. The obtained branching ratio $\mathcal{B}(B\rightarrow \chi_{c1}K^*_{0}(1430)(\rightarrow K^+\pi^-))=(5.1^{+0.6}_{-0.8})\times 10^{-5}$ consistent with the data from Belle within errors. Moreover, we also predict the differential distributions in the $hh'$ invariant mass for the decays under consideration, which await the future experimental test. In addition, the corresponding $\chi_{c1}(2P)$ channels are also investigated, which are helpful to clarify the nature of the $X(3872)$ state.
hep-ph/0503207
Stefan Scherer
I. Giller, A. Ocherashvili, T. Ebertshauser, M. A. Moinester, S. Scherer
A new determination of the $\gamma \pi \to \pi\pi$ anomalous amplitude via $\pi^- e^- \to \pi^- e^- \pi^{0}$ data
23 pages, 14 figures, discussion of the ChPT calculation extended
Eur.Phys.J. A25 (2005) 229-240
10.1140/epja/i2005-10116-1
MKPH-T-05-02
hep-ph hep-ex nucl-th
null
We discuss the reaction $\pi^- e^- \to \pi^- e^- \pi^{0}$ with the purpose of obtaining information on the $\gamma \pi \to \pi\pi$ anomalous amplitude ${\cal F}_{3\pi}$. We compare a full calculation at ${\cal O}(p^6)$ in chiral perturbation theory and various phenomenological predictions with the existing data of Amendolia {\em et al}. By integrating our theory results using Monte Carlo techniques we obtain $\sigma= 2.05 $ nb at ${\cal O}(p^6)$ and $\sigma= 2.17 $ nb after including the dominant electromagnetic correction. Both results are in good agreement with the experimental cross section of $\sigma= (2.11 \pm 0.47)$ nb. On the basis of the ChPT results one would extract from the the experimental cross section as amplitudes ${\cal F}_{3\pi}^{(0)\rm extr} = (9.9 \pm 1.1)$ GeV$^{-3}$ and ${\cal F}_{3\pi}^{(0)\rm extr} = (9.6 \pm 1.1)$ GeV$^{-3}$, respectively, which have to be compared with the low-energy theorem ${\cal F}_{3\pi}=e/(4\pi^2 F_\pi^3)=9.72 {GeV}^{-3}$. We emphasize the need for new data to allow for a comparison of experimental and theoretical distributions and to obtain ${\cal F}_{3\pi}$ with smaller uncertainty.
[ { "created": "Mon, 21 Mar 2005 17:16:48 GMT", "version": "v1" }, { "created": "Mon, 6 Jun 2005 11:01:55 GMT", "version": "v2" } ]
2009-11-11
[ [ "Giller", "I.", "" ], [ "Ocherashvili", "A.", "" ], [ "Ebertshauser", "T.", "" ], [ "Moinester", "M. A.", "" ], [ "Scherer", "S.", "" ] ]
We discuss the reaction $\pi^- e^- \to \pi^- e^- \pi^{0}$ with the purpose of obtaining information on the $\gamma \pi \to \pi\pi$ anomalous amplitude ${\cal F}_{3\pi}$. We compare a full calculation at ${\cal O}(p^6)$ in chiral perturbation theory and various phenomenological predictions with the existing data of Amendolia {\em et al}. By integrating our theory results using Monte Carlo techniques we obtain $\sigma= 2.05 $ nb at ${\cal O}(p^6)$ and $\sigma= 2.17 $ nb after including the dominant electromagnetic correction. Both results are in good agreement with the experimental cross section of $\sigma= (2.11 \pm 0.47)$ nb. On the basis of the ChPT results one would extract from the the experimental cross section as amplitudes ${\cal F}_{3\pi}^{(0)\rm extr} = (9.9 \pm 1.1)$ GeV$^{-3}$ and ${\cal F}_{3\pi}^{(0)\rm extr} = (9.6 \pm 1.1)$ GeV$^{-3}$, respectively, which have to be compared with the low-energy theorem ${\cal F}_{3\pi}=e/(4\pi^2 F_\pi^3)=9.72 {GeV}^{-3}$. We emphasize the need for new data to allow for a comparison of experimental and theoretical distributions and to obtain ${\cal F}_{3\pi}$ with smaller uncertainty.
hep-ph/9902335
Vladimir Shevchenko
N.O.Agasian, B.O.Kerbikov, V.I.Shevchenko
Nonperturbative QCD vacuum and Colour Superconductivity
LaTeX, 12 pages, reference added
Phys.Rept. 320 (1999) 131-138
10.1016/S0370-1573(99)00080-0
ITEP-TH-14-99
hep-ph
null
We discuss the possibility of existence of colour superconducting state in real QCD vacuum with nonzero gluon condensate. We argue, that nonperturbative gluonic fields might play a crucial role in colour superconductivity scenario.
[ { "created": "Fri, 12 Feb 1999 17:20:21 GMT", "version": "v1" }, { "created": "Thu, 11 Mar 1999 16:14:32 GMT", "version": "v2" } ]
2009-10-31
[ [ "Agasian", "N. O.", "" ], [ "Kerbikov", "B. O.", "" ], [ "Shevchenko", "V. I.", "" ] ]
We discuss the possibility of existence of colour superconducting state in real QCD vacuum with nonzero gluon condensate. We argue, that nonperturbative gluonic fields might play a crucial role in colour superconductivity scenario.
1803.00677
Sujay Shil
Pankaj Agrawal, Manimala Mitra, Saurabh Niyogi, Sujay Shil and Michael Spannowsky
Probing the Type-II Seesaw Mechanism through the Production of Higgs Bosons at a Lepton Collider
20 pages, 8 figures and 5 tables
Phys. Rev. D 98, 015024 (2018)
10.1103/PhysRevD.98.015024
IP/BBSR/2018-18, IPPP/18/14
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the production and decays of doubly-charged Higgs bosons for the Type-II seesaw mechanism at an $e^{+} e^{-}$ collider with two center of mass energies, $\sqrt{s}=380$ GeV and 3 TeV, and analyze the fully hadronic final states in detail. Lower mass ranges can be probed during the 380 GeV run of the collider, while high mass ranges, which are beyond the 13 TeV Large Hadron Collider discovery reach, can be probed with $\sqrt{s}=3$ TeV. For such a heavy Higgs boson, the final decay products are collimated, resulting in fat-jets. We perform a substructure analysis to reduce the background and find that a doubly-charged Higgs boson in the mass range 800-1120 GeV can be discovered during the 3 TeV run, with integrated luminosity $\mathcal{L} \sim 95\, \rm{fb}^{-1}$ of data. For 380 GeV center of mass energy, we find that for the doubly-charged Higgs boson in the range 160-172 GeV, a $5\sigma$ significance can be achieved with only integrated luminosity $\mathcal{L} \sim 24 \, \rm{fb}^{-1}$. Therefore, a light Higgs boson can be discovered immediately during the run of a future $e^{+} e^{-}$ collider.
[ { "created": "Fri, 2 Mar 2018 01:12:01 GMT", "version": "v1" } ]
2018-07-25
[ [ "Agrawal", "Pankaj", "" ], [ "Mitra", "Manimala", "" ], [ "Niyogi", "Saurabh", "" ], [ "Shil", "Sujay", "" ], [ "Spannowsky", "Michael", "" ] ]
We investigate the production and decays of doubly-charged Higgs bosons for the Type-II seesaw mechanism at an $e^{+} e^{-}$ collider with two center of mass energies, $\sqrt{s}=380$ GeV and 3 TeV, and analyze the fully hadronic final states in detail. Lower mass ranges can be probed during the 380 GeV run of the collider, while high mass ranges, which are beyond the 13 TeV Large Hadron Collider discovery reach, can be probed with $\sqrt{s}=3$ TeV. For such a heavy Higgs boson, the final decay products are collimated, resulting in fat-jets. We perform a substructure analysis to reduce the background and find that a doubly-charged Higgs boson in the mass range 800-1120 GeV can be discovered during the 3 TeV run, with integrated luminosity $\mathcal{L} \sim 95\, \rm{fb}^{-1}$ of data. For 380 GeV center of mass energy, we find that for the doubly-charged Higgs boson in the range 160-172 GeV, a $5\sigma$ significance can be achieved with only integrated luminosity $\mathcal{L} \sim 24 \, \rm{fb}^{-1}$. Therefore, a light Higgs boson can be discovered immediately during the run of a future $e^{+} e^{-}$ collider.
hep-ph/9908279
G. S. Krishnaswami
G. S. Krishnaswami and S. G. Rajeev (University of Rochester)
The x-dependence of Parton Distributions Compared with Neutrino Data
5 pages, RevTex
null
null
null
hep-ph
null
We use the variational principle of Quantum HadronDynamics, an alternative formulation of Quantum ChromoDynamics, to determine the wavefunction of valence quarks in a baryon at a low value of Q^2. This can be used to predict the structure function xF_3(x,Q^2) at higher values of Q^2 using the evolution equations of perturbative QCD. This prediction is compared to the measurements of neutrino scattering cross-section by the CDHS and CCFR experiments. The agreement is quite good, confirming the validity of QHD as a way of studying hadronic structure.
[ { "created": "Fri, 6 Aug 1999 03:33:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Krishnaswami", "G. S.", "", "University of Rochester" ], [ "Rajeev", "S. G.", "", "University of Rochester" ] ]
We use the variational principle of Quantum HadronDynamics, an alternative formulation of Quantum ChromoDynamics, to determine the wavefunction of valence quarks in a baryon at a low value of Q^2. This can be used to predict the structure function xF_3(x,Q^2) at higher values of Q^2 using the evolution equations of perturbative QCD. This prediction is compared to the measurements of neutrino scattering cross-section by the CDHS and CCFR experiments. The agreement is quite good, confirming the validity of QHD as a way of studying hadronic structure.
hep-ph/9909427
Spencer Klein
V. Emel'yanov, A. Khodinov, S.R. Klein and R. Vogt
The Effect of Shadowing on Initial Conditions, Transverse Energy and Hard Probes in Ultrarelativistic Heavy Ion Collisions
Submitted to Phys. Rev. C
Phys.Rev.C61:044904,2000
10.1103/PhysRevC.61.044904
LBNL-42900
hep-ph nucl-th
null
The effect of shadowing on the early state of ultrarelativistic heavy ion collisions is investigated along with transverse energy and hard process production, specifically Drell-Yan, $J/\psi$, and $\Upsilon$ production. We choose several parton distributions and parameterizations of nuclear shadowing, as well as the spatial dependence of shadowing, to study the influence of shadowing on relevant observables. Results are presented for Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and Pb+Pb collisions at $\sqrt{s_{NN}} = 5.5$ TeV.
[ { "created": "Fri, 17 Sep 1999 23:12:51 GMT", "version": "v1" } ]
2014-11-17
[ [ "Emel'yanov", "V.", "" ], [ "Khodinov", "A.", "" ], [ "Klein", "S. R.", "" ], [ "Vogt", "R.", "" ] ]
The effect of shadowing on the early state of ultrarelativistic heavy ion collisions is investigated along with transverse energy and hard process production, specifically Drell-Yan, $J/\psi$, and $\Upsilon$ production. We choose several parton distributions and parameterizations of nuclear shadowing, as well as the spatial dependence of shadowing, to study the influence of shadowing on relevant observables. Results are presented for Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and Pb+Pb collisions at $\sqrt{s_{NN}} = 5.5$ TeV.
hep-ph/0002019
Shin Muroya
N. Sasaki, O. Miyamura, S. Muroya and C. Nonaka
Baryon Diffusion Constant in Hot and Dense Hadronic Matter Based on an Event Generator Urasima
5 pages, 2 fugures, to appear in the proceedings of the 28th International Workshop on Gross Properties of Nuclei and Nuclear Excitation: Hadrons in Dense Matter (HIRSCHEGG 2000)
null
null
TWC-00-3
hep-ph
null
We generate the statistical ensembles in equilibrium with fixed temperature and chemical potential by imposing periodic boundary condition to the simulation of URASiMA(Ultra-Relativistic AA collision Simulator based on Multiple Scattering Algorithm). By using the generated ensembles, we investigate the temperature dependence and the chemical potential dependence of the nucleon diffusion constant of a dense and hot hadronic matter.
[ { "created": "Wed, 2 Feb 2000 08:54:24 GMT", "version": "v1" }, { "created": "Fri, 18 Feb 2000 05:35:26 GMT", "version": "v2" } ]
2007-05-23
[ [ "Sasaki", "N.", "" ], [ "Miyamura", "O.", "" ], [ "Muroya", "S.", "" ], [ "Nonaka", "C.", "" ] ]
We generate the statistical ensembles in equilibrium with fixed temperature and chemical potential by imposing periodic boundary condition to the simulation of URASiMA(Ultra-Relativistic AA collision Simulator based on Multiple Scattering Algorithm). By using the generated ensembles, we investigate the temperature dependence and the chemical potential dependence of the nucleon diffusion constant of a dense and hot hadronic matter.
hep-ph/0103122
Anindya Datta
Debrupa Chakraverty, Anindya Datta, Biswarup Mukhopadhyaya
Heavy quark production via supersymmetric interaction at a neutrino factory
Few typos are corrected in this version
Phys.Lett.B508:74-78,2001; Erratum-ibid.B519:285,2001
10.1016/S0370-2693(01)00483-X
MRI-P-010301
hep-ph
null
We investigate b-quark production in both charged and neutral current channels through neutrino-nucleon scattering at a neutrino factory, mediated by the lepton flavour violating interactions present in a supersymmetric theory with broken R-parity. Using values of the effctive interaction strengths well below the current and projected experimental bounds, we are still able to predict markedly enhanced event rates, especially for the neutral current events which are not allowed at the lowest order in the standard model (SM). Data from neutrino factories can therefore be used to probe strengths of such interactions to considerably higher precision than what can be envisioned in other experiments.
[ { "created": "Mon, 12 Mar 2001 16:43:35 GMT", "version": "v1" }, { "created": "Mon, 16 Apr 2001 18:04:18 GMT", "version": "v2" }, { "created": "Mon, 18 Jun 2001 09:00:56 GMT", "version": "v3" } ]
2011-07-19
[ [ "Chakraverty", "Debrupa", "" ], [ "Datta", "Anindya", "" ], [ "Mukhopadhyaya", "Biswarup", "" ] ]
We investigate b-quark production in both charged and neutral current channels through neutrino-nucleon scattering at a neutrino factory, mediated by the lepton flavour violating interactions present in a supersymmetric theory with broken R-parity. Using values of the effctive interaction strengths well below the current and projected experimental bounds, we are still able to predict markedly enhanced event rates, especially for the neutral current events which are not allowed at the lowest order in the standard model (SM). Data from neutrino factories can therefore be used to probe strengths of such interactions to considerably higher precision than what can be envisioned in other experiments.
2001.08762
Avik Banerjee
Avik Banerjee, Gautam Bhattacharyya, Palash B. Pal
SO(10) unification with horizontal symmetry
21 pages, 6 tables. v2: Further clarifications added primarily in Discussions Section, References updated, to be published in PRD
Phys. Rev. D 102, 015018 (2020)
10.1103/PhysRevD.102.015018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the nonsupersymmetric SO(10) grand unification theories by adding a horizontal symmetry, which connects the three generations of fermions. Without committing to any specific symmetry group, we investigate the 1-loop renormalization group evolutions of the gauge couplings with one and two intermediate breaking scales. We find that depending on the SO(10) breaking chains, gauge coupling unification is compatible with only a handful of choices of representations of the Higgs bosons under the horizontal symmetry.
[ { "created": "Thu, 23 Jan 2020 19:02:15 GMT", "version": "v1" }, { "created": "Sun, 12 Jul 2020 17:28:03 GMT", "version": "v2" } ]
2020-07-23
[ [ "Banerjee", "Avik", "" ], [ "Bhattacharyya", "Gautam", "" ], [ "Pal", "Palash B.", "" ] ]
We extend the nonsupersymmetric SO(10) grand unification theories by adding a horizontal symmetry, which connects the three generations of fermions. Without committing to any specific symmetry group, we investigate the 1-loop renormalization group evolutions of the gauge couplings with one and two intermediate breaking scales. We find that depending on the SO(10) breaking chains, gauge coupling unification is compatible with only a handful of choices of representations of the Higgs bosons under the horizontal symmetry.
0901.1020
Jong-Phil Lee
Jong-Phil Lee
Deconstructing unparticles in higher dimensions
9 pages. Minor changes, references added
Phys.Rev.D79:076002,2009
10.1103/PhysRevD.79.076002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Unparticles are realized by deconstruction in higher extra dimensions. It is shown that in this framework when the scale invariance is broken, the corresponding spectral function of the unparticle is shifted by an amount of the breaking scale. The result strongly supports the conventional ansatz for the spectral function of the unparticle in the literature.
[ { "created": "Thu, 8 Jan 2009 11:23:57 GMT", "version": "v1" }, { "created": "Fri, 13 Feb 2009 08:48:40 GMT", "version": "v2" } ]
2010-04-21
[ [ "Lee", "Jong-Phil", "" ] ]
Unparticles are realized by deconstruction in higher extra dimensions. It is shown that in this framework when the scale invariance is broken, the corresponding spectral function of the unparticle is shifted by an amount of the breaking scale. The result strongly supports the conventional ansatz for the spectral function of the unparticle in the literature.
1210.4801
Rathin Adhikari
Arnab Dasgupta, Zini Rahman, Rathin Adhikari
Discovery reach of $CP$ violation and non-standard interactions in low energy neutrino factory
16 pages, 8 figures (39 pdf files), text, figures modified
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In low energy neutrino factory ($E_{\mu}< 10$GeV) using MIND detector, we have studied the optimization of $CP$ violation discovery reach in the leptonic sector for different baselines and different parent muon energy considering only Standard Model interactions of neutrinos with matter. Considering such optimized experimental set-up of baseline and energy we have addressed the question of how $CP$ violation discovery reach could get affected by the presence of non-standard interactions of neutrinos with matter during the propagation of neutrinos. For off diagonal NSI elements there could be complex phases $\phi_{ij}$ which could also lead to $CP$ violation. In presence of these complex phases we have shown the contours showing the discovery reach of $\delta$ and $\phi_{ij}$. We have also shown the discovery reach of NSIs in the same experimental set-up which is optimized for discovery of $CP$ violation in the leptonic sector.
[ { "created": "Wed, 17 Oct 2012 17:43:55 GMT", "version": "v1" }, { "created": "Mon, 28 Jan 2013 11:59:18 GMT", "version": "v2" }, { "created": "Tue, 15 Apr 2014 13:59:38 GMT", "version": "v3" }, { "created": "Mon, 21 Apr 2014 12:55:30 GMT", "version": "v4" } ]
2014-04-22
[ [ "Dasgupta", "Arnab", "" ], [ "Rahman", "Zini", "" ], [ "Adhikari", "Rathin", "" ] ]
In low energy neutrino factory ($E_{\mu}< 10$GeV) using MIND detector, we have studied the optimization of $CP$ violation discovery reach in the leptonic sector for different baselines and different parent muon energy considering only Standard Model interactions of neutrinos with matter. Considering such optimized experimental set-up of baseline and energy we have addressed the question of how $CP$ violation discovery reach could get affected by the presence of non-standard interactions of neutrinos with matter during the propagation of neutrinos. For off diagonal NSI elements there could be complex phases $\phi_{ij}$ which could also lead to $CP$ violation. In presence of these complex phases we have shown the contours showing the discovery reach of $\delta$ and $\phi_{ij}$. We have also shown the discovery reach of NSIs in the same experimental set-up which is optimized for discovery of $CP$ violation in the leptonic sector.
2102.09784
Tong Li
Zikang Chen, Tong Li, Jiajun Liao
Constraints on general neutrino interactions with exotic fermion from neutrino-electron scattering experiments
18 pages, 5 figures, 1 table. Version published in JHEP
null
10.1007/JHEP05(2021)131
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The couplings between the neutrinos and exotic fermion can be probed in both neutrino scattering experiments and dark matter direct detection experiments. We present a detailed analysis of the general neutrino interactions with an exotic fermion and electrons at neutrino-electron scattering experiments. We obtain the constraints on the coupling coefficients of the scalar, pseudoscalar, vector, axialvector, tensor and electromagnetic dipole interactions from the CHARM-II, TEXONO and Borexino experiments. For the flavor-universal interactions, we find that the Borexino experiment sets the strongest bounds in the low mass region for the electromagnetic dipole interactions, and the CHARM-II experiment dominates the bounds for other scenarios. If the interactions are flavor dependent, the bounds from the CHARM-II or TEXONO experiment can be avoided, and there are correlations between the flavored coupling coefficients for the Borexino experiment. We also discuss the detection of sub-MeV DM absorbed by bound electron targets and illustrate that the vector coefficients preferred by XENON1T data is allowed by the neutrino experiments.
[ { "created": "Fri, 19 Feb 2021 08:03:03 GMT", "version": "v1" }, { "created": "Sat, 22 May 2021 08:22:02 GMT", "version": "v2" } ]
2021-06-02
[ [ "Chen", "Zikang", "" ], [ "Li", "Tong", "" ], [ "Liao", "Jiajun", "" ] ]
The couplings between the neutrinos and exotic fermion can be probed in both neutrino scattering experiments and dark matter direct detection experiments. We present a detailed analysis of the general neutrino interactions with an exotic fermion and electrons at neutrino-electron scattering experiments. We obtain the constraints on the coupling coefficients of the scalar, pseudoscalar, vector, axialvector, tensor and electromagnetic dipole interactions from the CHARM-II, TEXONO and Borexino experiments. For the flavor-universal interactions, we find that the Borexino experiment sets the strongest bounds in the low mass region for the electromagnetic dipole interactions, and the CHARM-II experiment dominates the bounds for other scenarios. If the interactions are flavor dependent, the bounds from the CHARM-II or TEXONO experiment can be avoided, and there are correlations between the flavored coupling coefficients for the Borexino experiment. We also discuss the detection of sub-MeV DM absorbed by bound electron targets and illustrate that the vector coefficients preferred by XENON1T data is allowed by the neutrino experiments.
1103.0008
Qing-Hong Cao
Qing-Hong Cao, Asan Damanik, Ernest Ma, Daniel Wegman
Probing Lepton Flavor Triality with Higgs Boson Decay
PRD version
Phys.Rev.D83:093012,2011
10.1103/PhysRevD.83.093012
ANL-HEP-PR-11-14, EFI-11-6, UCRHEP-T500
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If neutrino tribimaximal mixing is explained by a non-Abelian discrete symmetry such as $A_4$, $T_7$, $\Delta(27)$, etc., the charged-lepton Higgs sector has a $Z_3$ residual symmetry (lepton flavor triality), which may be observed directly in the decay chain $H^0 \to \psi_2^0 \bar\psi_2^0$, then $\psi_2^0 (\bar\psi_2^0) \to l_i^+ l_j^- ~(i \neq j)$, where $H^0$ is a standard-model-like Higgs boson and $\psi_2^0$ is a scalar particle needed for realizing the original discrete symmetry. If kinematically allowed, this unusual and easily detectable decay is observable at the LHC with 1 fb$^{-1}$ for E_{cm} = 7 TeV.
[ { "created": "Mon, 28 Feb 2011 21:00:05 GMT", "version": "v1" }, { "created": "Tue, 3 May 2011 18:22:53 GMT", "version": "v2" } ]
2011-07-08
[ [ "Cao", "Qing-Hong", "" ], [ "Damanik", "Asan", "" ], [ "Ma", "Ernest", "" ], [ "Wegman", "Daniel", "" ] ]
If neutrino tribimaximal mixing is explained by a non-Abelian discrete symmetry such as $A_4$, $T_7$, $\Delta(27)$, etc., the charged-lepton Higgs sector has a $Z_3$ residual symmetry (lepton flavor triality), which may be observed directly in the decay chain $H^0 \to \psi_2^0 \bar\psi_2^0$, then $\psi_2^0 (\bar\psi_2^0) \to l_i^+ l_j^- ~(i \neq j)$, where $H^0$ is a standard-model-like Higgs boson and $\psi_2^0$ is a scalar particle needed for realizing the original discrete symmetry. If kinematically allowed, this unusual and easily detectable decay is observable at the LHC with 1 fb$^{-1}$ for E_{cm} = 7 TeV.
0810.4462
Felipe J. Llanes-Estrada
Felipe J. Llanes-Estrada (Complutense Madrid), Pedro Bicudo, Marco Cardoso (IST Lisboa), Tim Van Cauteren (Ghent)
Parity doubling in the high baryon spectrum: near-degenerate three-quark quartets
Proceedings of the 2008 Bled miniworkshop "Few-Quark States and the Continuum". Three references added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on the first calculation of excited baryons with a chirally symmetric Hamiltonian, modeled after Coulomb gauge QCD (or upgraded from the Cornell meson potential model to a field theory in all of Fock-space) showing the insensitivity to chiral symmetry breaking. As has recently been understood, this leads to doubling between two hadrons of equal spin and opposite parity. As a novelty we show that three-quark, for example Delta states, group into quartets with two states of each parity, all four states having equal angular momentum J. Diagonalizing the chiral charge expressed in terms of quarks we show that the quartet is slightly split into two parity doublets by the tensor force, all splittings decreasing to zero high in the spectrum. Our specific calculation is for the family of maximum-spin excitations of the Delta baryon. We provide a model estimate of the experimental accuracy needed to establish Chiral Symmetry Restoration in the high spectrum. We suggest that a measurement of masses of high-partial wave Delta resonances with an accuracy of 50 MeV should be sufficient to unambiguously establish the approximate degeneracy, and test the concept of running quark mass in the infrared.
[ { "created": "Fri, 24 Oct 2008 13:45:09 GMT", "version": "v1" }, { "created": "Tue, 28 Oct 2008 12:01:29 GMT", "version": "v2" } ]
2008-10-28
[ [ "Llanes-Estrada", "Felipe J.", "", "Complutense Madrid" ], [ "Bicudo", "Pedro", "", "IST Lisboa" ], [ "Cardoso", "Marco", "", "IST Lisboa" ], [ "Van Cauteren", "Tim", "", "Ghent" ] ]
We report on the first calculation of excited baryons with a chirally symmetric Hamiltonian, modeled after Coulomb gauge QCD (or upgraded from the Cornell meson potential model to a field theory in all of Fock-space) showing the insensitivity to chiral symmetry breaking. As has recently been understood, this leads to doubling between two hadrons of equal spin and opposite parity. As a novelty we show that three-quark, for example Delta states, group into quartets with two states of each parity, all four states having equal angular momentum J. Diagonalizing the chiral charge expressed in terms of quarks we show that the quartet is slightly split into two parity doublets by the tensor force, all splittings decreasing to zero high in the spectrum. Our specific calculation is for the family of maximum-spin excitations of the Delta baryon. We provide a model estimate of the experimental accuracy needed to establish Chiral Symmetry Restoration in the high spectrum. We suggest that a measurement of masses of high-partial wave Delta resonances with an accuracy of 50 MeV should be sufficient to unambiguously establish the approximate degeneracy, and test the concept of running quark mass in the infrared.
hep-ph/9802322
Shi-Lin Zhu
Shi-Lin Zhu(1,2), W.-Y.P. Hwang(3) and Ze-sen Yang(1), ((1) Physics Department, Peking University, (2) Institute of Theoretical Physics, Academia Sinica, (3) Physics Department, National Taiwan University)
The $\Omega$ and $\Sigma^0$-$\Lambda$ transition magnetic moments in QCD sum rules
null
Phys.Rev. D57 (1998) 1527-1530
10.1103/PhysRevD.57.1527
null
hep-ph
null
The method of QCD sum rules in the presence of external elctromagnetic fields is used to calculate the $\Omega$ magnetic moment $\mu_{\Omega^-}$ and $\Sigma^0$-$\Lambda$ transition magnetic moment $\mu_{\Sigma^0\Lambda}$, with the susceptibilities obtained previously from the study of octet baryon magnetic moments. The results $\mu_{\Omega^-}=-1.92\mu_N$ and $\mu_{\Sigma^0\Lambda}=1.5\mu_N$ are in good agreement with the recent experimental data.
[ { "created": "Sat, 14 Feb 1998 02:36:00 GMT", "version": "v1" } ]
2009-10-31
[ [ "Zhu", "Shi-Lin", "" ], [ "Hwang", "W. -Y. P.", "" ], [ "Yang", "Ze-sen", "" ] ]
The method of QCD sum rules in the presence of external elctromagnetic fields is used to calculate the $\Omega$ magnetic moment $\mu_{\Omega^-}$ and $\Sigma^0$-$\Lambda$ transition magnetic moment $\mu_{\Sigma^0\Lambda}$, with the susceptibilities obtained previously from the study of octet baryon magnetic moments. The results $\mu_{\Omega^-}=-1.92\mu_N$ and $\mu_{\Sigma^0\Lambda}=1.5\mu_N$ are in good agreement with the recent experimental data.
hep-ph/0301243
George Sterman
George Sterman
From Long to Short Distances in Perturbative QCD
24 pages, eight eps figures. Based on talks presented at the International Conference on Theoretical Physics, TH2002, Paris, UNESCO, July 22-27, 2002, and the 26th Johns Hopkins Workshop on Current Problems in Particle Theory, Heidelberg, Aug. 1-3, 2002
Int.J.Mod.Phys.A18:4329-4342,2003; Annales Henri Poincare 4:S259-S273,2003
10.1142/S0217751X03016173
YITP-SB-02-80
hep-ph
null
Infrared safe differential cross sections, such as event shape distributions, can be measured over wide kinematic ranges, from regions where fixed order calculations are adequate to regions where nonperturbative dynamics dominate. Such observables provide an ideal laboratory for the study of the transition between weak and strong coupling in quantum field theory. This talk begins with some of the fundamentals of the perturbative description of QCD and the basis of resummation techniques, followed by a brief discussion of selected topics from recent fixed-order and resummed calculations. It focuses on how resummed perturbation theory has been used to deduce the structure of nonperturbative corrections, and to provide a framework with which to address the transition from short- to long-distance dynamics in QCD.
[ { "created": "Tue, 28 Jan 2003 12:17:37 GMT", "version": "v1" } ]
2014-11-17
[ [ "Sterman", "George", "" ] ]
Infrared safe differential cross sections, such as event shape distributions, can be measured over wide kinematic ranges, from regions where fixed order calculations are adequate to regions where nonperturbative dynamics dominate. Such observables provide an ideal laboratory for the study of the transition between weak and strong coupling in quantum field theory. This talk begins with some of the fundamentals of the perturbative description of QCD and the basis of resummation techniques, followed by a brief discussion of selected topics from recent fixed-order and resummed calculations. It focuses on how resummed perturbation theory has been used to deduce the structure of nonperturbative corrections, and to provide a framework with which to address the transition from short- to long-distance dynamics in QCD.
hep-ph/9511206
Tao Han
M. Golden, T. Han and G. Valencia
Strongly-Interacting Electroweak Sector --Model Independent Approaches--
Report contributed to ESB & BSM Book, ed. by T. Barklow, S. Dawson, H. Haber and J. Siegrist. LaTex file; 75 pages; 17 figures (not included here). Complete ps file available by anonymous ftp at ftp://ucdhep.ucdavis.edu/han/dpf/report/report_full.ps
null
10.1142/9789812830265_0005
UCD-95-32, ISU-HET-95-6
hep-ph
null
Phenomenology of a strongly-interacting electroweak symmetry breaking sector at current and future colliders is reviewed.
[ { "created": "Wed, 1 Nov 1995 21:20:50 GMT", "version": "v1" } ]
2016-11-03
[ [ "Golden", "M.", "" ], [ "Han", "T.", "" ], [ "Valencia", "G.", "" ] ]
Phenomenology of a strongly-interacting electroweak symmetry breaking sector at current and future colliders is reviewed.
1705.04419
Nagisa Hiroshima
Nagisa Hiroshima, Ryuichiro Kitano, Kazunori Kohri, Kohta Murase
High-energy Neutrinos from Multi-body Decaying Dark Matter
19 pages, 6 figures, to appear in PRD
Phys. Rev. D 97, 023006 (2018)
10.1103/PhysRevD.97.023006
KEK-Cosmo-202, KEK-TH-1979
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Since the report of the PeV-TeV neutrinos by the IceCube Collaboration, various particle physics models have been proposed to explain the neutrino spectrum by dark matter particles decaying into neutrinos and other Standard Model particles.In such scenarios, simultaneous $\gamma$-ray emission is commonly expected. Therefore, multi-messenger connections are generally important for the indirect searches of dark matters. The recent development of $\gamma$-ray astronomy puts stringent constraints on the properties of dark matter, especially by observations with the Fermi $\gamma$-ray satellite in the last several years. Motivated by the lack of $\gamma$-ray as well as the shape of the neutrino spectrum observed by IceCube, we discuss a scenario in which the DM is a PeV scale particle which couples strongly to other invisible particles and its decay products do not contain a charged particle. As an example to realize such possibilities, we consider a model of fermionic dark matter that decays into a neutrino and many invisible fermions. The dark matter decay is secluded in the sense that the emitted products are mostly neutrinos and dark fermions. One remarkable feature of this model is the resulting broadband neutrino spectra around the energy scale of the dark matter. We apply this model to multi-PeV dark matter, and discuss possible observable consequences in light of the IceCube data. In particular, this model could account for the large flux at medium energies of $\sim10-100$ TeV, possibly as well as the second peak at PeV, without violating the stringent $\gamma$-ray constraints from Fermi and air-shower experiments such as CASA-MIA.
[ { "created": "Fri, 12 May 2017 01:42:05 GMT", "version": "v1" }, { "created": "Thu, 14 Dec 2017 12:49:05 GMT", "version": "v2" } ]
2018-01-17
[ [ "Hiroshima", "Nagisa", "" ], [ "Kitano", "Ryuichiro", "" ], [ "Kohri", "Kazunori", "" ], [ "Murase", "Kohta", "" ] ]
Since the report of the PeV-TeV neutrinos by the IceCube Collaboration, various particle physics models have been proposed to explain the neutrino spectrum by dark matter particles decaying into neutrinos and other Standard Model particles.In such scenarios, simultaneous $\gamma$-ray emission is commonly expected. Therefore, multi-messenger connections are generally important for the indirect searches of dark matters. The recent development of $\gamma$-ray astronomy puts stringent constraints on the properties of dark matter, especially by observations with the Fermi $\gamma$-ray satellite in the last several years. Motivated by the lack of $\gamma$-ray as well as the shape of the neutrino spectrum observed by IceCube, we discuss a scenario in which the DM is a PeV scale particle which couples strongly to other invisible particles and its decay products do not contain a charged particle. As an example to realize such possibilities, we consider a model of fermionic dark matter that decays into a neutrino and many invisible fermions. The dark matter decay is secluded in the sense that the emitted products are mostly neutrinos and dark fermions. One remarkable feature of this model is the resulting broadband neutrino spectra around the energy scale of the dark matter. We apply this model to multi-PeV dark matter, and discuss possible observable consequences in light of the IceCube data. In particular, this model could account for the large flux at medium energies of $\sim10-100$ TeV, possibly as well as the second peak at PeV, without violating the stringent $\gamma$-ray constraints from Fermi and air-shower experiments such as CASA-MIA.
1707.04121
J. Wallace Van Orden
J. W. Van Orden, T. W. Donnelly, O. Moreno
Coincidence charged-current neutrino-induced deuteron disintegration for $^2\mathrm{H}_2{^{16}}\mathrm{O}$
null
Phys. Rev. D 96, 113008 (2017)
10.1103/PhysRevD.96.113008
JLAB-THY-17-2515
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Semi-inclusive charge-changing neutrino reactions on targets of heavy water are investigated with the goal of determining the relative contributions to the total cross section of deuterium and oxygen in kinematics chosen to emphasize the former. The study is undertaken for conditions where the typical neutrino beam energies are in the few GeV region, and hence relativistic modeling is essential. For this, the previous relativistic approach for the deuteron is employed, together with a spectral function approach for the case of oxygen. Upon optimizing the kinematics of the final-state particles assumed to be detected (typically a muon and a proton) it is shown that the oxygen contribution to the total cross section is suppressed by roughly an order of magnitude compared with the deuterium cross section, thereby confirming that CC$\nu$ studies of heavy water can effectively yield the cross sections for deuterium, with acceptable backgrounds from oxygen. This opens the possibility of using deuterium to determine the incident neutrino flux distribution, to have it serve as a target for which the nuclear structure issues are minimal, and possibly to use deuterium to provide improved knowledge of specific aspects of hadronic structure, such as to explore the momentum transfer dependence of the isovector axial-vector form factor of the nucleon.
[ { "created": "Thu, 13 Jul 2017 13:48:51 GMT", "version": "v1" } ]
2018-01-03
[ [ "Van Orden", "J. W.", "" ], [ "Donnelly", "T. W.", "" ], [ "Moreno", "O.", "" ] ]
Semi-inclusive charge-changing neutrino reactions on targets of heavy water are investigated with the goal of determining the relative contributions to the total cross section of deuterium and oxygen in kinematics chosen to emphasize the former. The study is undertaken for conditions where the typical neutrino beam energies are in the few GeV region, and hence relativistic modeling is essential. For this, the previous relativistic approach for the deuteron is employed, together with a spectral function approach for the case of oxygen. Upon optimizing the kinematics of the final-state particles assumed to be detected (typically a muon and a proton) it is shown that the oxygen contribution to the total cross section is suppressed by roughly an order of magnitude compared with the deuterium cross section, thereby confirming that CC$\nu$ studies of heavy water can effectively yield the cross sections for deuterium, with acceptable backgrounds from oxygen. This opens the possibility of using deuterium to determine the incident neutrino flux distribution, to have it serve as a target for which the nuclear structure issues are minimal, and possibly to use deuterium to provide improved knowledge of specific aspects of hadronic structure, such as to explore the momentum transfer dependence of the isovector axial-vector form factor of the nucleon.