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hep-ph/0207159
Boris Ermolaev
B.I. Ermolaev, S.M. Oliveira and S.I. Troyan
Production of electroweak bosons in e+e- annihilation at high energies
Revtex4, 16 pages, 7 figures, 2 tables
Phys.Rev. D66 (2002) 114018
10.1103/PhysRevD.66.114018
null
hep-ph
null
Production of electroweak bosons in e+e- annihilation into quarks and into leptons at energies much greater than 100 Gev is considered. We account for double-logarithmic contributions to all orders in electroweak couplings. It is assumed that the bosons are emitted in the multi-Regge kinematics. The explicit expressions for the scattering amplitudes of the process are obtained. It is shown that the cross sections of the photon and Z production have the identical energy dependence and asymptotically their ratio depends only on the Weinberg angle whereas the energy dependence of the cross section of the W production is suppressed by factor s^{-0.4} compared to them.
[ { "created": "Fri, 12 Jul 2002 14:36:33 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ermolaev", "B. I.", "" ], [ "Oliveira", "S. M.", "" ], [ "Troyan", "S. I.", "" ] ]
Production of electroweak bosons in e+e- annihilation into quarks and into leptons at energies much greater than 100 Gev is considered. We account for double-logarithmic contributions to all orders in electroweak couplings. It is assumed that the bosons are emitted in the multi-Regge kinematics. The explicit expressions for the scattering amplitudes of the process are obtained. It is shown that the cross sections of the photon and Z production have the identical energy dependence and asymptotically their ratio depends only on the Weinberg angle whereas the energy dependence of the cross section of the W production is suppressed by factor s^{-0.4} compared to them.
hep-ph/9810552
Guo-Hong Wu
Ken Kiers, Amarjit Soni, Guo-Hong Wu
CP Violation in a two-Higgs doublet model for the top quark: B to psi K_S
14 pages, 2 figures. Added a new case study and a figure, some discussions, and a few references; version to appear in Phys. ReV. D
Phys.Rev. D59 (1999) 096001
10.1103/PhysRevD.59.096001
BNL-HET-98/41, PURD-TH-98-12
hep-ph hep-ex
null
We explore charged-Higgs CP-violating effects in an intriguing two-Higgs doublet model which accords special status to the top quark. In this model the heaviness of the top quark originates naturally from the much larger VEV of the second Higgs doublet compared to that of the first. The phenomenology of this model is quite distinct from that of the usual formulations of the two-Higgs doublet model. In particular, the model can easily account for the observed CP violation in the kaon sector even if the CKM matrix is real. The associated non-standard CP phase can be monitored through measurements of the time-dependent CP asymmetry in B to psi K_S in experiments at the upcoming B-factories.
[ { "created": "Fri, 30 Oct 1998 21:32:35 GMT", "version": "v1" }, { "created": "Wed, 27 Jan 1999 21:25:18 GMT", "version": "v2" } ]
2009-10-31
[ [ "Kiers", "Ken", "" ], [ "Soni", "Amarjit", "" ], [ "Wu", "Guo-Hong", "" ] ]
We explore charged-Higgs CP-violating effects in an intriguing two-Higgs doublet model which accords special status to the top quark. In this model the heaviness of the top quark originates naturally from the much larger VEV of the second Higgs doublet compared to that of the first. The phenomenology of this model is quite distinct from that of the usual formulations of the two-Higgs doublet model. In particular, the model can easily account for the observed CP violation in the kaon sector even if the CKM matrix is real. The associated non-standard CP phase can be monitored through measurements of the time-dependent CP asymmetry in B to psi K_S in experiments at the upcoming B-factories.
0907.2357
Fredrick Olness
I. Schienbein, J. Y. Yu, K. Kovarik, C. Keppel, J. G. Morfin, F. Olness, J.F. Owens
PDF Nuclear Corrections for Charged Lepton and Neutrino Deep Inelastic Scattering Processes
LaTeX, 9 pages, 5 figures; Version 2 contains minor updates to match journal version
Phys.Rev.D80:094004,2009
10.1103/PhysRevD.80.094004
LPSC 09-081; SMU-HEP 09-13
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a \chi^2-analysis of Nuclear Parton Distribution Functions (NPDFs) using neutral current charged-lepton Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets. The nuclear A dependence of the NPDFs is extracted in a next-to-leading order fit. We compare the nuclear corrections factors F2(Fe)/F2(D) for this charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.
[ { "created": "Tue, 14 Jul 2009 16:06:53 GMT", "version": "v1" }, { "created": "Thu, 11 Feb 2010 20:09:57 GMT", "version": "v2" } ]
2010-02-11
[ [ "Schienbein", "I.", "" ], [ "Yu", "J. Y.", "" ], [ "Kovarik", "K.", "" ], [ "Keppel", "C.", "" ], [ "Morfin", "J. G.", "" ], [ "Olness", "F.", "" ], [ "Owens", "J. F.", "" ] ]
We perform a \chi^2-analysis of Nuclear Parton Distribution Functions (NPDFs) using neutral current charged-lepton Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets. The nuclear A dependence of the NPDFs is extracted in a next-to-leading order fit. We compare the nuclear corrections factors F2(Fe)/F2(D) for this charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.
2203.00057
Michael Kagan
Lukas Heinrich and Michael Kagan
Differentiable Matrix Elements with MadJax
6 pages, Proceedings of the 20th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2021)
null
10.1088/1742-6596/2438/1/012137
null
hep-ph cs.LG physics.comp-ph physics.data-an
http://creativecommons.org/licenses/by/4.0/
MadJax is a tool for generating and evaluating differentiable matrix elements of high energy scattering processes. As such, it is a step towards a differentiable programming paradigm in high energy physics that facilitates the incorporation of high energy physics domain knowledge, encoded in simulation software, into gradient based learning and optimization pipelines. MadJax comprises two components: (a) a plugin to the general purpose matrix element generator MadGraph that integrates matrix element and phase space sampling code with the JAX differentiable programming framework, and (b) a standalone wrapping API for accessing the matrix element code and its gradients, which are computed with automatic differentiation. The MadJax implementation and example applications of simulation based inference and normalizing flow based matrix element modeling, with capabilities enabled uniquely with differentiable matrix elements, are presented.
[ { "created": "Mon, 28 Feb 2022 19:53:44 GMT", "version": "v1" } ]
2023-03-01
[ [ "Heinrich", "Lukas", "" ], [ "Kagan", "Michael", "" ] ]
MadJax is a tool for generating and evaluating differentiable matrix elements of high energy scattering processes. As such, it is a step towards a differentiable programming paradigm in high energy physics that facilitates the incorporation of high energy physics domain knowledge, encoded in simulation software, into gradient based learning and optimization pipelines. MadJax comprises two components: (a) a plugin to the general purpose matrix element generator MadGraph that integrates matrix element and phase space sampling code with the JAX differentiable programming framework, and (b) a standalone wrapping API for accessing the matrix element code and its gradients, which are computed with automatic differentiation. The MadJax implementation and example applications of simulation based inference and normalizing flow based matrix element modeling, with capabilities enabled uniquely with differentiable matrix elements, are presented.
0707.2101
Bennie F. L. Ward
B.F.L. Ward (1) ((1) Baylor University, Waco, TX, USA)
Quark Masses and Resummation in Precision QCD Theory
12 pages, 2 figures; corrected misprint; added material to clarify text
Phys.Rev.D78:056001,2008
10.1103/PhysRevD.78.056001
BU-HEPP-07-04
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that amplitude-based, exact resummation tames the un-cancelled IR divergences at O(alpha_s^2) in initial state radiation in QCD with massive quarks. Implications for precision predictions for LHC physics are discussed.
[ { "created": "Sat, 14 Jul 2007 18:06:56 GMT", "version": "v1" }, { "created": "Sat, 27 Oct 2007 16:18:30 GMT", "version": "v2" }, { "created": "Wed, 24 Sep 2008 19:04:50 GMT", "version": "v3" } ]
2008-11-07
[ [ "Ward", "B. F. L.", "", "Baylor University, Waco, TX, USA" ] ]
It is shown that amplitude-based, exact resummation tames the un-cancelled IR divergences at O(alpha_s^2) in initial state radiation in QCD with massive quarks. Implications for precision predictions for LHC physics are discussed.
hep-ph/0001283
Sergio F. Novaes
S. F. Novaes (Instituto de Fisica Teorica, UNESP)
Standard Model: An Introduction
101 pages, 14 figures, To be published in "Particle and Fields", Proceedings of the X J. A. Swieca Summer School (World Scientific, Singapore, 2000)
null
null
IFT-P.010/2000
hep-ph hep-ex
null
We present a primer on the Standard Model of the electroweak interaction. Emphasis is given to the historical aspects of the theory's formulation. The radiative corrections to the Standard Model are presented and its predictions for the electroweak parameters are compared with the precise experimental data obtained at the Z pole. Finally, we make some remarks on the perspectives for the discovery of the Higgs boson, the most important challenge of the Standard Model.
[ { "created": "Thu, 27 Jan 2000 16:31:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Novaes", "S. F.", "", "Instituto de Fisica Teorica, UNESP" ] ]
We present a primer on the Standard Model of the electroweak interaction. Emphasis is given to the historical aspects of the theory's formulation. The radiative corrections to the Standard Model are presented and its predictions for the electroweak parameters are compared with the precise experimental data obtained at the Z pole. Finally, we make some remarks on the perspectives for the discovery of the Higgs boson, the most important challenge of the Standard Model.
hep-ph/9811429
Yuri Arestov
Yu. Arestov (1) and F.R.A. Simao (2) ((1) IHEP, Protvino (2) CBPF, Rio de Janeiro)
Polarization properties of diffractively produced \Lambda_c^+
10 pages, 4 figures. Talk at 13th Int. Symp. on High Energy Spin Physics, Protvino, Sept. 1998
null
null
IHEP 98-58
hep-ph
null
The Pomeron-gluon-gluon interaction is considered in the QCD-based model for the charmed baryon production in the process Pomeron + p --> \Lambda_c^+ + X. The polarization of the produced heavy quark is induced effectively through the non-perturbative long-range interaction with the gluon field of the type [sigma*rotA]. The x_F-dependence of \Lambda_c^+ polarization, P_(x_F,p_T), has been studied. Its absolute value depends on the model parameter a and it appears to be sizeable in the wide range of a values: when a ranges from 0.1 to 1.0, the polarization P(x_F,p_T) varies from --0.2 to --0.5 at x_F ~ 0.5 and p_T in the interval 1 - 2 GeV/c.
[ { "created": "Sat, 21 Nov 1998 00:49:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Arestov", "Yu.", "" ], [ "Simao", "F. R. A.", "" ] ]
The Pomeron-gluon-gluon interaction is considered in the QCD-based model for the charmed baryon production in the process Pomeron + p --> \Lambda_c^+ + X. The polarization of the produced heavy quark is induced effectively through the non-perturbative long-range interaction with the gluon field of the type [sigma*rotA]. The x_F-dependence of \Lambda_c^+ polarization, P_(x_F,p_T), has been studied. Its absolute value depends on the model parameter a and it appears to be sizeable in the wide range of a values: when a ranges from 0.1 to 1.0, the polarization P(x_F,p_T) varies from --0.2 to --0.5 at x_F ~ 0.5 and p_T in the interval 1 - 2 GeV/c.
1104.1418
Yu Jia
Yu Jia, Xiu-Ting Yang, Wen-Long Sang, and Jia Xu
$O(\alpha_s v^2)$ correction to pseudoscalar quarkonium decay to two photons
v2, 28 pages, 2 figures and 2 tables, matching the published version; typos corrected, references added, as well as a "Note added in the proof"
null
10.1007/JHEP06(2011)097
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the $O(\alpha_s v^2)$ correction to the process of pseudoscalar quarkonium decay to two photons in nonrelativistic QCD (NRQCD) factorization framework. The short-distance coefficient associated with the relative-order $v^2$ NRQCD matrix element is determined to next-to-leading order in $\alpha_s$ through the perturbative matching procedure. Some technical subtleties encountered in calculating the ${O(\alpha_s)$ QCD amplitude are thoroughly addressed.
[ { "created": "Thu, 7 Apr 2011 19:50:40 GMT", "version": "v1" }, { "created": "Mon, 20 Jun 2011 18:48:25 GMT", "version": "v2" } ]
2015-05-27
[ [ "Jia", "Yu", "" ], [ "Yang", "Xiu-Ting", "" ], [ "Sang", "Wen-Long", "" ], [ "Xu", "Jia", "" ] ]
We investigate the $O(\alpha_s v^2)$ correction to the process of pseudoscalar quarkonium decay to two photons in nonrelativistic QCD (NRQCD) factorization framework. The short-distance coefficient associated with the relative-order $v^2$ NRQCD matrix element is determined to next-to-leading order in $\alpha_s$ through the perturbative matching procedure. Some technical subtleties encountered in calculating the ${O(\alpha_s)$ QCD amplitude are thoroughly addressed.
hep-ph/9610391
Thomas A. DeGrand
T. DeGrand (U. of Colorado)
Lattice Gauge Theory for QCD
48 pages, LaTeX file. Postscript figures embedded using epsf. Lectures presented at 1996 SLAC Summer Institute
null
null
COLO-HEP-378
hep-ph hep-lat
null
These lectures provide an introduction to lattice methods for nonperturbative studies of Quantum Chromodynamics. Lecture 1 (Ch. 2): Basic techniques for QCD and results for hadron spectroscopy using the simplest discretizations; lecture 2 (Ch. 3): ``improved actions''--what they are and how well they work lecture 3 (Ch. 4): SLAC physics from the lattice: structure functions, the mass of the glueball, heavy quarks and $\alpha_s(M_Z)$, and $B-\bar B$ mixing.
[ { "created": "Thu, 17 Oct 1996 16:26:27 GMT", "version": "v1" } ]
2016-09-06
[ [ "DeGrand", "T.", "", "U. of Colorado" ] ]
These lectures provide an introduction to lattice methods for nonperturbative studies of Quantum Chromodynamics. Lecture 1 (Ch. 2): Basic techniques for QCD and results for hadron spectroscopy using the simplest discretizations; lecture 2 (Ch. 3): ``improved actions''--what they are and how well they work lecture 3 (Ch. 4): SLAC physics from the lattice: structure functions, the mass of the glueball, heavy quarks and $\alpha_s(M_Z)$, and $B-\bar B$ mixing.
1403.4788
Petar Petrov
Frank Krauss, Petar Petrov, Marek Schoenherr, Michael Spannowsky
Measuring collinear W emissions inside jets
13 pages, 9 figures
Phys. Rev. D 89, 114006 (2014)
10.1103/PhysRevD.89.114006
IPPP/14/04, DCPT/14/08, MCNET-14-06, LPN14-054
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Single and multiple emission of electroweak gauge bosons and in particular of W bosons is discussed in the parton shower language. Algorithms and observables for the reconstruction of both leptonically and hadronically decaying W bosons inside light quark jets are compared, and they are applied to a study of how emission rates of W bosons in light-jet events at the LHC could be measured.
[ { "created": "Wed, 19 Mar 2014 12:54:42 GMT", "version": "v1" } ]
2014-06-11
[ [ "Krauss", "Frank", "" ], [ "Petrov", "Petar", "" ], [ "Schoenherr", "Marek", "" ], [ "Spannowsky", "Michael", "" ] ]
Single and multiple emission of electroweak gauge bosons and in particular of W bosons is discussed in the parton shower language. Algorithms and observables for the reconstruction of both leptonically and hadronically decaying W bosons inside light quark jets are compared, and they are applied to a study of how emission rates of W bosons in light-jet events at the LHC could be measured.
2307.07061
Anne-Katherine Burns
Anne-Katherine Burns, Tim M.P. Tait and Mauro Valli
PRyMordial: The First Three Minutes, Within and Beyond the Standard Model
33 pages, 5 figures, 2 tables; comments are welcome; code at https://github.com/vallima/PRyMordial v2: A few refs added, typos corrected, examples updated according to most recent version of PRyMordial
null
null
UCI-HEP-TR-2023-07, YITP-SB-2023-16
hep-ph astro-ph.CO nucl-th
http://creativecommons.org/licenses/by/4.0/
In this work we present PRyMordial: A package dedicated to efficient computations of observables in the Early Universe with the focus on the cosmological era of Big Bang Nucleosynthesis (BBN). The code offers fast and precise evaluation of BBN light-element abundances together with the effective number of relativistic degrees of freedom, including non-instantaneous decoupling effects. PRyMordial is suitable for state-of-the-art analyses in the Standard Model as well as for general investigations into New Physics active during BBN. After reviewing the physics implemented in PRyMordial, we provide a short guide on how to use the code for applications in the Standard Model and beyond. The package is written in Python, but more advanced users can optionally take advantage of the open-source community for Julia. PRyMordial is publicly available on GitHub.
[ { "created": "Thu, 13 Jul 2023 20:59:01 GMT", "version": "v1" }, { "created": "Fri, 4 Aug 2023 00:10:47 GMT", "version": "v2" } ]
2023-08-07
[ [ "Burns", "Anne-Katherine", "" ], [ "Tait", "Tim M. P.", "" ], [ "Valli", "Mauro", "" ] ]
In this work we present PRyMordial: A package dedicated to efficient computations of observables in the Early Universe with the focus on the cosmological era of Big Bang Nucleosynthesis (BBN). The code offers fast and precise evaluation of BBN light-element abundances together with the effective number of relativistic degrees of freedom, including non-instantaneous decoupling effects. PRyMordial is suitable for state-of-the-art analyses in the Standard Model as well as for general investigations into New Physics active during BBN. After reviewing the physics implemented in PRyMordial, we provide a short guide on how to use the code for applications in the Standard Model and beyond. The package is written in Python, but more advanced users can optionally take advantage of the open-source community for Julia. PRyMordial is publicly available on GitHub.
1607.07898
U. J. Salda\~na-Salazar
U. J. Saldana-Salazar
A principle for the Yukawa couplings
5 pages; to be published in Journal of Physics Conference Series (IOP). Joint Proceedings of the XV Mexican Workshop on Particles and Fields & the XXX Annual Meeting of the Division of Particles and Fields of the Mexican Physical Society
null
10.1088/1742-6596/761/1/012064
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Yukawa couplings in the Standard Model are introduced in its most general form, that is, completely arbitrary complex numbers. Here we show that their origin could not be general but dictated by a principle.
[ { "created": "Tue, 26 Jul 2016 20:56:47 GMT", "version": "v1" } ]
2016-11-23
[ [ "Saldana-Salazar", "U. J.", "" ] ]
Yukawa couplings in the Standard Model are introduced in its most general form, that is, completely arbitrary complex numbers. Here we show that their origin could not be general but dictated by a principle.
hep-ph/0101336
Andrzej Buras
Andrzej J. Buras
Flavour Dynamics: CP Violation and Rare Decays
latex-file and 12 figures, 117 pages. Lectures given at the Erice School: 27 August-5 September 2000
null
10.1142/9789812778253_0005
TUM-HEP-402/01
hep-ph
null
These lectures give an up to date description of CP violation and rare decays of K and B mesons and consist of ten chapters: i) Grand view of the field including CKM matrix and the unitarity triangle, ii) General aspects of the theoretical framework based on effective weak Hamiltonians, the operator product expansion and the renormalization group, iii) Particle-antiparticle mixing and various types of CP violation, iv) Standard analysis of the unitarity triangle, v) The ratio epsilon'/epsilon, vi) Rare decays K^+ -> pi^+ nu barnu and K_L to pi^0 nu barnu, vii) Express review of other rare decays, viii) CP violation in B decays, ix) A brief look beyond the Standard Model discussing in particular the models with minimal flavour violation, x) Perspectives for the coming years.
[ { "created": "Tue, 30 Jan 2001 15:32:27 GMT", "version": "v1" } ]
2017-08-23
[ [ "Buras", "Andrzej J.", "" ] ]
These lectures give an up to date description of CP violation and rare decays of K and B mesons and consist of ten chapters: i) Grand view of the field including CKM matrix and the unitarity triangle, ii) General aspects of the theoretical framework based on effective weak Hamiltonians, the operator product expansion and the renormalization group, iii) Particle-antiparticle mixing and various types of CP violation, iv) Standard analysis of the unitarity triangle, v) The ratio epsilon'/epsilon, vi) Rare decays K^+ -> pi^+ nu barnu and K_L to pi^0 nu barnu, vii) Express review of other rare decays, viii) CP violation in B decays, ix) A brief look beyond the Standard Model discussing in particular the models with minimal flavour violation, x) Perspectives for the coming years.
hep-ph/9902422
Hiroshi Yokota
Hisao Nakkagawa and Hiroshi Yokota (Nara University, Japan)
Massive $\phi^4$ Model at Finite Temperature -- Resummayion Procedure la RG Improvement --
6 pages, Latex file with sprocl.sty and epsf.sty, including 1 figure (eps.file). Talk presented at 1998 YITP-Workshop on QCD and Hadron Physics. To be published in Proceedings
null
null
NUTP-9901
hep-ph
null
In this paper the phase structure of the massive $\lambda \phi^4$ model at finite temperature ($T \neq 0$) is investigated by applying a resummation method inspired by the renormalization-group (RG) improvement to the one-loop effective potential. The resummation method a la RG-improvement is shown to work quite succesfully by resumming up systematically large correction-terms of $O(\lambda T/\mu)$ and of $O(\lambda (T/\mu)^2)$. The temperature-dependent phase transition of the model is shown to proceed through the second order transition. The critical exponents are determined analytically and are compared with those in other analyses.
[ { "created": "Mon, 22 Feb 1999 07:23:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nakkagawa", "Hisao", "", "Nara University, Japan" ], [ "Yokota", "Hiroshi", "", "Nara University, Japan" ] ]
In this paper the phase structure of the massive $\lambda \phi^4$ model at finite temperature ($T \neq 0$) is investigated by applying a resummation method inspired by the renormalization-group (RG) improvement to the one-loop effective potential. The resummation method a la RG-improvement is shown to work quite succesfully by resumming up systematically large correction-terms of $O(\lambda T/\mu)$ and of $O(\lambda (T/\mu)^2)$. The temperature-dependent phase transition of the model is shown to proceed through the second order transition. The critical exponents are determined analytically and are compared with those in other analyses.
hep-ph/0209147
Walter Winter
Bjorn Jacobsson, Tommy Ohlsson, Hakan Snellman, and Walter Winter
The effects of matter density uncertainties on neutrino oscillations in the Earth
3 pages, 1 figure. Talk given at the NuFact'02 Workshop, London, 1-6 July, 2002
J.Phys.G29:1873-1876,2003
10.1088/0954-3899/29/8/364
TUM-HEP-477/02
hep-ph
null
We compare three different methods to evaluate uncertainties in the Earth's matter density profile, which are relevant to long baseline experiments, such as neutrino factories.
[ { "created": "Fri, 13 Sep 2002 08:37:23 GMT", "version": "v1" } ]
2008-11-26
[ [ "Jacobsson", "Bjorn", "" ], [ "Ohlsson", "Tommy", "" ], [ "Snellman", "Hakan", "" ], [ "Winter", "Walter", "" ] ]
We compare three different methods to evaluate uncertainties in the Earth's matter density profile, which are relevant to long baseline experiments, such as neutrino factories.
2309.03346
Ted Rogers
John Collins and Ted Rogers
On the definition of fragmentation functions and the violation of sum rules
Final version appearing in Physical Review D
null
null
null
hep-ph hep-th nucl-th
http://creativecommons.org/licenses/by/4.0/
We point out a problem with the formulation and derivations of sum rules for quark fragmentation functions that impacts their validity in QCD, but which potentially points toward an improved understanding of final states in inclusive hard processes. Fragmentation functions give the distribution of final-state hadrons arising from a parton exiting a hard scattering, and the sum rules for momentum, electric charge, etc express conservation of these quantities. The problem arises from a mismatch between the quark quantum numbers of the initial quark and the fact that all observed final-state hadrons are confined bound states with color zero. We point that, in a confining theory like QCD, the Wilson line in the operator definition of a fragmentation function entails that the final state in a fragmentation function includes a bound state in the external field generated by the Wilson line. We justify this with the aid of general features of string hadronization. The anomalous bound states are restricted to fractional momentum $z=0$. They tend to invalidate sum rules like the one for charge conservation when applied to the fragmentation functions inferred from experimental data, but not the momentum sum rule. We propose to exploit our ideas in future studies as a way to relate the ffs extracted from inclusive cross sections to more detailed non-perturbative descriptions of final state hadronization. We also describe scenarios wherein the traditional sum rules might remain approximately valid with a reasonably high degree of accuracy.
[ { "created": "Wed, 6 Sep 2023 20:01:02 GMT", "version": "v1" }, { "created": "Mon, 25 Sep 2023 22:57:40 GMT", "version": "v2" }, { "created": "Sun, 14 Jan 2024 18:43:27 GMT", "version": "v3" } ]
2024-01-17
[ [ "Collins", "John", "" ], [ "Rogers", "Ted", "" ] ]
We point out a problem with the formulation and derivations of sum rules for quark fragmentation functions that impacts their validity in QCD, but which potentially points toward an improved understanding of final states in inclusive hard processes. Fragmentation functions give the distribution of final-state hadrons arising from a parton exiting a hard scattering, and the sum rules for momentum, electric charge, etc express conservation of these quantities. The problem arises from a mismatch between the quark quantum numbers of the initial quark and the fact that all observed final-state hadrons are confined bound states with color zero. We point that, in a confining theory like QCD, the Wilson line in the operator definition of a fragmentation function entails that the final state in a fragmentation function includes a bound state in the external field generated by the Wilson line. We justify this with the aid of general features of string hadronization. The anomalous bound states are restricted to fractional momentum $z=0$. They tend to invalidate sum rules like the one for charge conservation when applied to the fragmentation functions inferred from experimental data, but not the momentum sum rule. We propose to exploit our ideas in future studies as a way to relate the ffs extracted from inclusive cross sections to more detailed non-perturbative descriptions of final state hadronization. We also describe scenarios wherein the traditional sum rules might remain approximately valid with a reasonably high degree of accuracy.
1110.2147
Muneyuki Ishida
V. Barger, M. Ishida and W.-Y.Keung
Searching for Stoponium along with the Higgs boson
10 pages 5 figures
null
10.1103/PhysRevLett.108.081804
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Stoponium, a bound state of top squark and its antiparticle in a supersymmetric model, may be found in the ongoing Higgs searches at the LHC. Its WW and ZZ detection ratios relative to the Standard Model Higgs boson can be more than unity from WW* threshold to the two Higgs threshold. The gamma gamma channel is equally promising. Some regions of the stoponium mass below 150 GeV are already being probed by the ATLAS and CMS experiments.
[ { "created": "Mon, 10 Oct 2011 19:02:08 GMT", "version": "v1" }, { "created": "Tue, 15 May 2012 22:29:53 GMT", "version": "v2" } ]
2013-05-30
[ [ "Barger", "V.", "" ], [ "Ishida", "M.", "" ], [ "Keung", "W. -Y.", "" ] ]
Stoponium, a bound state of top squark and its antiparticle in a supersymmetric model, may be found in the ongoing Higgs searches at the LHC. Its WW and ZZ detection ratios relative to the Standard Model Higgs boson can be more than unity from WW* threshold to the two Higgs threshold. The gamma gamma channel is equally promising. Some regions of the stoponium mass below 150 GeV are already being probed by the ATLAS and CMS experiments.
hep-ph/0209220
Vladimir Saleev
V.A.Saleev and D.V.Vasin
On charmonia and charmed mesons photoproduction at high energy
Talk was presented at International Seminar "Heavy quark - 2002", JINR, Dubna, Russia, May-June, 2002. In version 2 we have corrected numerical results for the D^star meson spectra
Phys.Lett. B548 (2002) 161-174
10.1016/S0370-2693(02)02845-9
null
hep-ph
null
We compare the predictions of the collinear parton model and the k_T-factorization approach in J\Psi and D^\star meson photoproduction at HERA energies. It is shown that obtained in the both approaches D^\star meson spectra over p_T and \eta as well as J\Psi meson p_T- and z-spectra are very different. The predictions obtained in the k_T-factorization approach are agree with the experimental data well. We also predict the nontrivial p_T-dependence of the the spin parameter $\alpha(p_T) in the J\Psi photoproduction.
[ { "created": "Thu, 19 Sep 2002 11:48:22 GMT", "version": "v1" }, { "created": "Sat, 8 Nov 2003 09:22:43 GMT", "version": "v2" } ]
2009-11-07
[ [ "Saleev", "V. A.", "" ], [ "Vasin", "D. V.", "" ] ]
We compare the predictions of the collinear parton model and the k_T-factorization approach in J\Psi and D^\star meson photoproduction at HERA energies. It is shown that obtained in the both approaches D^\star meson spectra over p_T and \eta as well as J\Psi meson p_T- and z-spectra are very different. The predictions obtained in the k_T-factorization approach are agree with the experimental data well. We also predict the nontrivial p_T-dependence of the the spin parameter $\alpha(p_T) in the J\Psi photoproduction.
hep-ph/0703131
Gabriel Guerrer
Ignacio Bediaga, Gabriel Guerrer and Jussara M. de Miranda
CKM $\gamma$ phase from $B \to K \pi \pi$
4 pages, 2 figures. To appear in the proceedings of the 4th International Workshop on the CKM Unitarity Triangle, december 12-16 2006, Nagoya, Japan
null
null
null
hep-ph
null
We discuss a method to extract the CKM $\gamma$ angle combining Dalitz plot analysis of $B^{\pm} \to K^{\pm} \pi^+ \pi^-$ and untagged $B^0$, $\bar B^0 \to K_s \pi^+ \pi^-$. The method also allows obtaining the ratio and phase difference between the {\it tree} and {\it penguin} contributions from $B^0$ and $\bar B^0 \to K^{*\pm} \pi^{\mp} $ decays and direct CP asymmetry between $B^0$ and $\bar{B^0}$. From Monte Carlo studies of 100K events for the neutral mesons, we show the possibility of measuring $\gamma$ with a precision of $\sim 5^o$.
[ { "created": "Mon, 12 Mar 2007 20:01:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bediaga", "Ignacio", "" ], [ "Guerrer", "Gabriel", "" ], [ "de Miranda", "Jussara M.", "" ] ]
We discuss a method to extract the CKM $\gamma$ angle combining Dalitz plot analysis of $B^{\pm} \to K^{\pm} \pi^+ \pi^-$ and untagged $B^0$, $\bar B^0 \to K_s \pi^+ \pi^-$. The method also allows obtaining the ratio and phase difference between the {\it tree} and {\it penguin} contributions from $B^0$ and $\bar B^0 \to K^{*\pm} \pi^{\mp} $ decays and direct CP asymmetry between $B^0$ and $\bar{B^0}$. From Monte Carlo studies of 100K events for the neutral mesons, we show the possibility of measuring $\gamma$ with a precision of $\sim 5^o$.
hep-ph/0403038
Tamas Biro S.
T.S. Biro and G. Purcsel
A Non-Extensive Model for Quark Matter Produced in Heavy Ion Collisions
LaTeX, revtex4, prc, 16 pages
null
null
null
hep-ph
null
We describe quark matter in the framework of non-extensive thermodynamics. We point out that partcile spectra with power-law tail lead to an increased energy and entropy per particle. This way even a massless plasma may give E/N = 1 GeV at T = 175 MeV temperature, alike thermal hadronic fits to RHIC experiment. In this case E/NT = 6 instead of 3.
[ { "created": "Wed, 3 Mar 2004 12:53:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Biro", "T. S.", "" ], [ "Purcsel", "G.", "" ] ]
We describe quark matter in the framework of non-extensive thermodynamics. We point out that partcile spectra with power-law tail lead to an increased energy and entropy per particle. This way even a massless plasma may give E/N = 1 GeV at T = 175 MeV temperature, alike thermal hadronic fits to RHIC experiment. In this case E/NT = 6 instead of 3.
hep-ph/0501253
Hai-Yang Cheng
Hai-Yang Cheng, Kwei-Chou Yang
$B\to f_0(980)K$ Decays and Subleading Corrections
28 pages, 10 figures. Experimental branching ratios of B-> f_0 K are updated, typos corrected and references added
Phys.Rev. D71 (2005) 054020
10.1103/PhysRevD.71.054020
null
hep-ph hep-ex
null
The decay $B\to f_0(980)K is studied within the framework of QCD factorization and the two-quark scenario for $f_0(980)$. There are two distinct penguin contributions and their interference depends on the unknown mixing angle $\theta$ of strange and nonstrange quark contents of $f_0(980)$: destructive for $0<\theta<\pi/2$ and constructive for $\pi/2<\theta<\pi$. The QCD sum rule method is applied to evaluate the leading-twist light-cone distribution amplitudes and the scalar decay constant of $f_0$. We conclude that the short-distance approach is not adequate to explain the observed large rates of $f_0K^-$ and $f_0\ov K^0$. Among many possible subleading corrections, we study and estimate the contributions from the three-parton Fock states of the $f_0$ and from the intrinsic gluon inside the $B$ meson. It is found that the spectator gluon of the $B$ meson may play an eminent role for the enhancement of $f_0(980)K$. We point out that if $f_0(980)$ is a four-quark state as widely perceived, there will exist extra diagrams contributing to $B\to f_0(980)K$. However, in practice it is difficult to make quantitative predictions based on the four-quark picture for $f_0(980)$ as it involves additional nonfactorizable contributions that are difficult to estimate and the calculations of the decay constant and form factors of $f_0(980)$ are beyond the conventional quark model.
[ { "created": "Thu, 27 Jan 2005 02:22:17 GMT", "version": "v1" }, { "created": "Tue, 22 Feb 2005 15:08:27 GMT", "version": "v2" } ]
2009-11-11
[ [ "Cheng", "Hai-Yang", "" ], [ "Yang", "Kwei-Chou", "" ] ]
The decay $B\to f_0(980)K is studied within the framework of QCD factorization and the two-quark scenario for $f_0(980)$. There are two distinct penguin contributions and their interference depends on the unknown mixing angle $\theta$ of strange and nonstrange quark contents of $f_0(980)$: destructive for $0<\theta<\pi/2$ and constructive for $\pi/2<\theta<\pi$. The QCD sum rule method is applied to evaluate the leading-twist light-cone distribution amplitudes and the scalar decay constant of $f_0$. We conclude that the short-distance approach is not adequate to explain the observed large rates of $f_0K^-$ and $f_0\ov K^0$. Among many possible subleading corrections, we study and estimate the contributions from the three-parton Fock states of the $f_0$ and from the intrinsic gluon inside the $B$ meson. It is found that the spectator gluon of the $B$ meson may play an eminent role for the enhancement of $f_0(980)K$. We point out that if $f_0(980)$ is a four-quark state as widely perceived, there will exist extra diagrams contributing to $B\to f_0(980)K$. However, in practice it is difficult to make quantitative predictions based on the four-quark picture for $f_0(980)$ as it involves additional nonfactorizable contributions that are difficult to estimate and the calculations of the decay constant and form factors of $f_0(980)$ are beyond the conventional quark model.
1111.2615
Shufang Su
Jonathan Eckel, William Shepherd and Shufang Su
Slepton Discovery in Electroweak Cascade Decay
20 pages, 5 figures
null
10.1007/JHEP05(2012)081
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHC studies on the MSSM slepton sector have mostly been focused on direct slepton Drell-Yan pair production. In this paper, we analyze the case when the sleptons are lighter than heavy neutralinos and can appear in the on-shell decay of neutralino states. In particular, we have studied the \chi_1^\pm \chi_2^0 associated production, with the consequent decays of \chi_1^\pm and \chi_2^0 via on-shell sleptons. The invariant mass of the lepton pairs, m_{\ell\ell}, from the neutralino decay has a distinctive triangle shape with a sharp kinematic cutoff. We discuss the utilization of this triangle shape in m_{\ell\ell} distribution to identify the slepton signal. We studied the trilepton plus missing E_T signal and obtained the effective cross section, \sigma \times BR \times acceptance, that is needed for a 5\sigma discovery as a function of the cutoff mass for the LHC with center of mass energy 14 TeV and 100 fb^{-1} integrated luminosity. Our results are model independent such that they could be applied to other models with similar decay topology. When applied to the MSSM under simple assumptions, it is found that with 100 fb^{-1} integrated luminosity, a discovery reach in the left-handed slepton mass of about 600 GeV could be reached, which extends far beyond the slepton mass reach in the usual Drell-Yan studies.
[ { "created": "Thu, 10 Nov 2011 21:06:38 GMT", "version": "v1" } ]
2015-06-03
[ [ "Eckel", "Jonathan", "" ], [ "Shepherd", "William", "" ], [ "Su", "Shufang", "" ] ]
The LHC studies on the MSSM slepton sector have mostly been focused on direct slepton Drell-Yan pair production. In this paper, we analyze the case when the sleptons are lighter than heavy neutralinos and can appear in the on-shell decay of neutralino states. In particular, we have studied the \chi_1^\pm \chi_2^0 associated production, with the consequent decays of \chi_1^\pm and \chi_2^0 via on-shell sleptons. The invariant mass of the lepton pairs, m_{\ell\ell}, from the neutralino decay has a distinctive triangle shape with a sharp kinematic cutoff. We discuss the utilization of this triangle shape in m_{\ell\ell} distribution to identify the slepton signal. We studied the trilepton plus missing E_T signal and obtained the effective cross section, \sigma \times BR \times acceptance, that is needed for a 5\sigma discovery as a function of the cutoff mass for the LHC with center of mass energy 14 TeV and 100 fb^{-1} integrated luminosity. Our results are model independent such that they could be applied to other models with similar decay topology. When applied to the MSSM under simple assumptions, it is found that with 100 fb^{-1} integrated luminosity, a discovery reach in the left-handed slepton mass of about 600 GeV could be reached, which extends far beyond the slepton mass reach in the usual Drell-Yan studies.
2102.07136
Howard E. Haber
Howard E. Haber and Joao P. Silva
Exceptional regions of the 2HDM parameter space
103 pages, 12 tables, version 2 adds subsections in Sections 5, 6, and 7. Additional references added and a number of clarifications and minor additions included; version 3 closely resembles the published version; version 4 adds some additional cases in Tables 8 and 9; version 5 matches the Erratum published in Phys. Rev. D 105, 119902 (2022)
Phys. Rev. D 103, 115012 (2021)
10.1103/PhysRevD.103.115012
CFTP/21-001 and SCIPP-21/01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The exceptional region of the parameter space (ERPS) of the two Higgs doublet model (2HDM) is defined to be the parameter regime where the scalar potential takes on a very special form. In the standard parameterization of the 2HDM scalar potential with squared mass parameters $m_{11}^2$, $m_{22}^2$, $m_{12}^2$, and dimensionless couplings, $\lambda_1$, $\lambda_2$, $\ldots,\lambda_7$, the ERPS corresponds to $\lambda_1=\lambda_2$, $\lambda_7=-\lambda_6$, $m_{11}^2=m_{22}^2$ and $m_{12}^2=0$, corresponding to a scalar potential with an enhanced generalized CP symmetry called GCP2. Many special features persist if $\lambda_1=\lambda_2$ and $\lambda_7=-\lambda_6$ are retained while allowing for $m_{11}^2\neq m_{22}^2$ and/or $m_{12}^2\neq 0$, corresponding to a scalar potential with a softly-broken GCP2 symmetry, which we designate as the ERPS4. In this paper, we examine many of the special features of the ERPS4, as well as even more specialized cases within the ERPS4 framework in which additional constraints on the scalar potential parameters are imposed. By surveying the landscape of the ERPS4, we complete the classification of 2HDM scalar potentials that exhibit an exact Higgs alignment (where the tree-level couplings of one neutral scalar coincide with those of the Standard Model Higgs boson), due to a residual symmetry that is unbroken in the vacuum. One surprising aspect of the ERPS4 is the possibility that the scalar sector is CP-conserving despite the presence of a complex parameter of the scalar potential whose complex phase cannot be removed by separate rephasings of the two scalar doublet fields. The significance of the ERPS4 regime for custodial symmetry is also discussed, and the cases where a custodial symmetric 2HDM scalar potential preserves an exact Higgs alignment are elucidated.
[ { "created": "Sun, 14 Feb 2021 12:19:51 GMT", "version": "v1" }, { "created": "Sat, 10 Apr 2021 12:02:53 GMT", "version": "v2" }, { "created": "Fri, 11 Jun 2021 05:40:30 GMT", "version": "v3" }, { "created": "Tue, 17 May 2022 11:12:32 GMT", "version": "v4" }, { "created": "Wed, 29 Jun 2022 17:25:08 GMT", "version": "v5" } ]
2022-06-30
[ [ "Haber", "Howard E.", "" ], [ "Silva", "Joao P.", "" ] ]
The exceptional region of the parameter space (ERPS) of the two Higgs doublet model (2HDM) is defined to be the parameter regime where the scalar potential takes on a very special form. In the standard parameterization of the 2HDM scalar potential with squared mass parameters $m_{11}^2$, $m_{22}^2$, $m_{12}^2$, and dimensionless couplings, $\lambda_1$, $\lambda_2$, $\ldots,\lambda_7$, the ERPS corresponds to $\lambda_1=\lambda_2$, $\lambda_7=-\lambda_6$, $m_{11}^2=m_{22}^2$ and $m_{12}^2=0$, corresponding to a scalar potential with an enhanced generalized CP symmetry called GCP2. Many special features persist if $\lambda_1=\lambda_2$ and $\lambda_7=-\lambda_6$ are retained while allowing for $m_{11}^2\neq m_{22}^2$ and/or $m_{12}^2\neq 0$, corresponding to a scalar potential with a softly-broken GCP2 symmetry, which we designate as the ERPS4. In this paper, we examine many of the special features of the ERPS4, as well as even more specialized cases within the ERPS4 framework in which additional constraints on the scalar potential parameters are imposed. By surveying the landscape of the ERPS4, we complete the classification of 2HDM scalar potentials that exhibit an exact Higgs alignment (where the tree-level couplings of one neutral scalar coincide with those of the Standard Model Higgs boson), due to a residual symmetry that is unbroken in the vacuum. One surprising aspect of the ERPS4 is the possibility that the scalar sector is CP-conserving despite the presence of a complex parameter of the scalar potential whose complex phase cannot be removed by separate rephasings of the two scalar doublet fields. The significance of the ERPS4 regime for custodial symmetry is also discussed, and the cases where a custodial symmetric 2HDM scalar potential preserves an exact Higgs alignment are elucidated.
1707.08980
Matti Heikinheimo
Matti Heikinheimo, Kristjan Kannike, Florian Lyonnet, Martti Raidal, Kimmo Tuominen and Hardi Veerm\"ae
Vacuum Stability and Perturbativity of SU(3) Scalars
26 pages, 6 figures, 2 tables
null
10.1007/JHEP10(2017)014
HIP-2017-19/TH
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the vacuum stability conditions and renormalisation group equations for the extensions of standard model with a higher colour multiplet scalar up to the representation $\mathbf{15'}$ that leaves the strong interaction asymptotically free. In order to find the vacuum stability conditions, we calculate the orbit spaces for the self-couplings of the higher multiplets, which for the representations $\mathbf{15}$ and $\mathbf{15'}$ of $SU(3)_c$ are highly complicated. However, if the scalar potential is linear in orbit space variables, it is sufficient to know the convex hull of the orbit space. In contrast to the self-couplings of other multiplets, we find that the scalar quartic couplings of the representations $\mathbf{3}$ and $\mathbf{8}$ walk rather than run, remaining nearly constant and perturbative over a vast energy range. We describe the conditions for walking couplings using a schematic model. With these technical results at hand we revise earlier results of generation of new scales with large $SU(3)_c$ scalar multiplets. Our results are easily extendable to models of new physics with additional $SU(3)$ or SU($N$) gauge symmetries.
[ { "created": "Thu, 27 Jul 2017 18:02:46 GMT", "version": "v1" } ]
2017-10-25
[ [ "Heikinheimo", "Matti", "" ], [ "Kannike", "Kristjan", "" ], [ "Lyonnet", "Florian", "" ], [ "Raidal", "Martti", "" ], [ "Tuominen", "Kimmo", "" ], [ "Veermäe", "Hardi", "" ] ]
We calculate the vacuum stability conditions and renormalisation group equations for the extensions of standard model with a higher colour multiplet scalar up to the representation $\mathbf{15'}$ that leaves the strong interaction asymptotically free. In order to find the vacuum stability conditions, we calculate the orbit spaces for the self-couplings of the higher multiplets, which for the representations $\mathbf{15}$ and $\mathbf{15'}$ of $SU(3)_c$ are highly complicated. However, if the scalar potential is linear in orbit space variables, it is sufficient to know the convex hull of the orbit space. In contrast to the self-couplings of other multiplets, we find that the scalar quartic couplings of the representations $\mathbf{3}$ and $\mathbf{8}$ walk rather than run, remaining nearly constant and perturbative over a vast energy range. We describe the conditions for walking couplings using a schematic model. With these technical results at hand we revise earlier results of generation of new scales with large $SU(3)_c$ scalar multiplets. Our results are easily extendable to models of new physics with additional $SU(3)$ or SU($N$) gauge symmetries.
1012.3377
Nan Su
Nan Su
QCD Thermodynamics at Intermediate Coupling
3 pages, 2 figures; talk given at the conference "Quark Confinement and the Hadron Spectrum IX", August 30 - September 3, 2010, Madrid, Spain; to appear in the AIP proceedings
AIP Conf.Proc.1343:510-512,2011
10.1063/1.3575078
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The weak-coupling expansion of the QCD free energy is known to order g_s^6log{g_s}, however, the resulting series is poorly convergent at phenomenologically relevant temperatures. In this proceedings, I discuss hard-thermal-loop perturbation theory (HTLpt) which is a gauge-invariant reorganization of the perturbative expansion for gauge theories. I review a recent NNLO HTLpt calculation of QCD thermodynamic functions. I show that the NNLO HTLpt results are consistent with lattice data down to temperatures T~2T_c.
[ { "created": "Wed, 15 Dec 2010 16:22:47 GMT", "version": "v1" }, { "created": "Mon, 20 Dec 2010 17:38:14 GMT", "version": "v2" } ]
2011-06-21
[ [ "Su", "Nan", "" ] ]
The weak-coupling expansion of the QCD free energy is known to order g_s^6log{g_s}, however, the resulting series is poorly convergent at phenomenologically relevant temperatures. In this proceedings, I discuss hard-thermal-loop perturbation theory (HTLpt) which is a gauge-invariant reorganization of the perturbative expansion for gauge theories. I review a recent NNLO HTLpt calculation of QCD thermodynamic functions. I show that the NNLO HTLpt results are consistent with lattice data down to temperatures T~2T_c.
1208.2598
Jambul Gegelia
T. Bauer, J. Gegelia, S. Scherer
Magnetic moment of the Roper resonance
13 pages, 4 figures
Physics Letters B 715 (2012) pp. 234-240
10.1016/j.physletb.2012.07.032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The magnetic moment of the Roper resonance is calculated in the framework of a low-energy effective field theory of the strong interactions. A systematic power-counting procedure is implemented by applying the complex-mass scheme.
[ { "created": "Mon, 13 Aug 2012 14:25:28 GMT", "version": "v1" } ]
2015-06-11
[ [ "Bauer", "T.", "" ], [ "Gegelia", "J.", "" ], [ "Scherer", "S.", "" ] ]
The magnetic moment of the Roper resonance is calculated in the framework of a low-energy effective field theory of the strong interactions. A systematic power-counting procedure is implemented by applying the complex-mass scheme.
hep-ph/9408294
Martin John Savage
Martin J. Savage
E2 Strength in the Radiative Charmed Baryon Decay
10 pages, 2 uuencoded figures included, uses harvmac and epsf, CMU-HEP 94-25
Phys.Lett.B345:61-66,1995
10.1016/0370-2693(94)01597-6
null
hep-ph
null
The radiative decay $\Sigma_Q^* \rightarrow \Lambda_Q\gamma$ can have both magnetic dipole (M1) and electric quadrupole (E2) components. In the heavy quark limit $M_Q\rightarrow\infty$ the transition arises from the spin of the light degrees of freedom changing from $s_l=1$ to $s_l=0$ and hence the E2 contribution vanishes. We compute the leading contribution to the E2 strength in chiral perturbation theory and find that the amplitude is enhanced by a small energy denominator in the chiral limit. This enhancement essentially compensates for the $1/M_c$ suppression that is present in the charm system. We find a mixing ratio of order a few percent dependent upon the $\Sigma_c^*--\Sigma_c$ spin symmetry breaking mass difference. The analogous quantity in the b-baryon sector is smaller by a factor of $\sim M_c/M_b$.
[ { "created": "Mon, 15 Aug 1994 16:29:33 GMT", "version": "v1" } ]
2010-11-01
[ [ "Savage", "Martin J.", "" ] ]
The radiative decay $\Sigma_Q^* \rightarrow \Lambda_Q\gamma$ can have both magnetic dipole (M1) and electric quadrupole (E2) components. In the heavy quark limit $M_Q\rightarrow\infty$ the transition arises from the spin of the light degrees of freedom changing from $s_l=1$ to $s_l=0$ and hence the E2 contribution vanishes. We compute the leading contribution to the E2 strength in chiral perturbation theory and find that the amplitude is enhanced by a small energy denominator in the chiral limit. This enhancement essentially compensates for the $1/M_c$ suppression that is present in the charm system. We find a mixing ratio of order a few percent dependent upon the $\Sigma_c^*--\Sigma_c$ spin symmetry breaking mass difference. The analogous quantity in the b-baryon sector is smaller by a factor of $\sim M_c/M_b$.
1805.06588
Rui-Lin Zhu
Ruilin Zhu, Yan Ma, Xin-Ling Han, Zhen-Jun Xiao
Form factors for semileptonic $B_{c}$ decays into $\eta^{(')}$ and Glueball
11 pages, 8 figures, and 5 tables
Phys. Rev. D 98, 114035 (2018)
10.1103/PhysRevD.98.114035
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculated the form factors of $B_{c}$ transitions into $\eta^{(')}$ meson and pseudoscalar Glueball, where the $B_{c}$ meson is a bound state of two different heavy flavors and is treated as a nonrelativistic state, while the mesons $\eta^{(')}$ and Glueball are treated as light-cone objects since their masses are smaller enough compared to the transition momentum scale. The mechanism of two gluon scattering into $\eta^{(')}$ dominated the form factors of $B_{c}$ decays into $\eta^{(')}$. We considered the $\eta-\eta'-$Glueball mixing effect, and then obtained their influences on the form factors. The form factors of $B_{c}$ transitions into $\eta^{(')}$ and pseudoscalar Glueball in the maximum momentum recoil point were obtained as follows: $f^\eta_{0,+}(q^2=0)=1.38^{+0.00}_{-0.02}\times 10^{-3}$,$f^{\eta'}_{0,+}(q^2=0)=0.89^{+0.11}_{-0.10}\times 10^{-2}$ and $f^{G}_{0,+}(q^2=0)=0.44^{+0.13}_{-0.05}\times 10^{-2}$. Also phenomenological discussions for semileptonic $B_{c}\to\eta^{(')}+\ell+\bar{\nu}_\ell$, $B_{c}\to G(0^{-+})+\ell+\bar{\nu}_\ell$ and $D_{s}\to \eta+\ell+\bar{\nu}_\ell$ decays are given.
[ { "created": "Thu, 17 May 2018 03:06:42 GMT", "version": "v1" }, { "created": "Sat, 29 Dec 2018 12:51:50 GMT", "version": "v2" } ]
2019-01-02
[ [ "Zhu", "Ruilin", "" ], [ "Ma", "Yan", "" ], [ "Han", "Xin-Ling", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
We calculated the form factors of $B_{c}$ transitions into $\eta^{(')}$ meson and pseudoscalar Glueball, where the $B_{c}$ meson is a bound state of two different heavy flavors and is treated as a nonrelativistic state, while the mesons $\eta^{(')}$ and Glueball are treated as light-cone objects since their masses are smaller enough compared to the transition momentum scale. The mechanism of two gluon scattering into $\eta^{(')}$ dominated the form factors of $B_{c}$ decays into $\eta^{(')}$. We considered the $\eta-\eta'-$Glueball mixing effect, and then obtained their influences on the form factors. The form factors of $B_{c}$ transitions into $\eta^{(')}$ and pseudoscalar Glueball in the maximum momentum recoil point were obtained as follows: $f^\eta_{0,+}(q^2=0)=1.38^{+0.00}_{-0.02}\times 10^{-3}$,$f^{\eta'}_{0,+}(q^2=0)=0.89^{+0.11}_{-0.10}\times 10^{-2}$ and $f^{G}_{0,+}(q^2=0)=0.44^{+0.13}_{-0.05}\times 10^{-2}$. Also phenomenological discussions for semileptonic $B_{c}\to\eta^{(')}+\ell+\bar{\nu}_\ell$, $B_{c}\to G(0^{-+})+\ell+\bar{\nu}_\ell$ and $D_{s}\to \eta+\ell+\bar{\nu}_\ell$ decays are given.
1001.0987
Hai-Yang Cheng
Hai-Yang Cheng, Cheng-Wei Chiang
Two-body hadronic charmed meson decays
32 pages, 5 figures. An alternative method for error bar extraction is used; last columns of Tables~I to VI, and all entries in Tables~VII, VIII and X are modified. To appear in PRD.
Phys.Rev.D81:074021,2010
10.1103/PhysRevD.81.074021
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study in this work the two-body hadronic charmed meson decays, including both the PP and VP modes. The latest experimental data are first analyzed in the diagrammatic approach. The magnitudes and strong phases of the flavor amplitudes are extracted from the Cabibbo-favored (CF) decay modes using $\chi^2$ minimization. The best-fitted values are then used to predict the branching fractions of the singly-Cabibbo-suppressed (SCS) and doubly-Cabibbo-suppressed decay modes in the flavor SU(3) symmetry limit. We observe significant SU(3) breaking effects in some of SCS channels. In the case of VP modes, we point out that the $A_P$ and $A_V$ amplitudes cannot be completely determined based on currently available data. We conjecture that the quoted experimental results for both $D_s^+\to\bar K^0K^{*+}$ and $D_s^+\to \rho^+\eta'$ are overestimated. We compare the sizes of color-allowed and color-suppressed tree amplitudes extracted from the diagrammatical approach with the effective parameters $a_1$ and $a_2$ defined in the factorization approach. The ratio $|a_2/a_1|$ is more or less universal among the $D \to {\bar K} \pi$, ${\bar K}^* \pi$ and ${\bar K} \rho$ modes. This feature allows us to discriminate between different solutions of topological amplitudes. For the long-standing puzzle about the ratio $\Gamma(D^0\to K^+K^-)/\Gamma(D^0\to\pi^+\pi^-)$, we argue that, in addition to the SU(3) breaking effect in the spectator amplitudes, the long-distance resonant contribution through the nearby resonance $f_0(1710)$ can naturally explain why $D^0$ decays more copiously to $K^+ K^-$ than $\pi^+ \pi^-$ through the $W$-exchange topology.
[ { "created": "Wed, 6 Jan 2010 21:37:37 GMT", "version": "v1" }, { "created": "Wed, 10 Mar 2010 02:20:26 GMT", "version": "v2" } ]
2010-05-28
[ [ "Cheng", "Hai-Yang", "" ], [ "Chiang", "Cheng-Wei", "" ] ]
We study in this work the two-body hadronic charmed meson decays, including both the PP and VP modes. The latest experimental data are first analyzed in the diagrammatic approach. The magnitudes and strong phases of the flavor amplitudes are extracted from the Cabibbo-favored (CF) decay modes using $\chi^2$ minimization. The best-fitted values are then used to predict the branching fractions of the singly-Cabibbo-suppressed (SCS) and doubly-Cabibbo-suppressed decay modes in the flavor SU(3) symmetry limit. We observe significant SU(3) breaking effects in some of SCS channels. In the case of VP modes, we point out that the $A_P$ and $A_V$ amplitudes cannot be completely determined based on currently available data. We conjecture that the quoted experimental results for both $D_s^+\to\bar K^0K^{*+}$ and $D_s^+\to \rho^+\eta'$ are overestimated. We compare the sizes of color-allowed and color-suppressed tree amplitudes extracted from the diagrammatical approach with the effective parameters $a_1$ and $a_2$ defined in the factorization approach. The ratio $|a_2/a_1|$ is more or less universal among the $D \to {\bar K} \pi$, ${\bar K}^* \pi$ and ${\bar K} \rho$ modes. This feature allows us to discriminate between different solutions of topological amplitudes. For the long-standing puzzle about the ratio $\Gamma(D^0\to K^+K^-)/\Gamma(D^0\to\pi^+\pi^-)$, we argue that, in addition to the SU(3) breaking effect in the spectator amplitudes, the long-distance resonant contribution through the nearby resonance $f_0(1710)$ can naturally explain why $D^0$ decays more copiously to $K^+ K^-$ than $\pi^+ \pi^-$ through the $W$-exchange topology.
hep-ph/9712379
Yuichiro Kiyo
Michihiro Hori, Yuichiro Kiyo and Takashi Nasuno
Optimal Spin Basis in Polarized Photon Linear Colliders
RevTeX, 16 pages, 6 figures, psfig.sty and here.sty are required
Phys. Rev. D 58, 014005 (1998)
10.1103/PhysRevD.58.014005
HUPD-9712
hep-ph
null
We analyze the spin correlations of the top quark pairs produced at Photon Linear Colliders. We employ the circular polarized photon beams and general spin basis for the top quark pair. We consider general spin bases to find a strong spin correlation between produced top quark and anti-top quark. We show the cross-section in these bases and discuss the characteristics of results.
[ { "created": "Mon, 15 Dec 1997 15:46:05 GMT", "version": "v1" } ]
2016-08-25
[ [ "Hori", "Michihiro", "" ], [ "Kiyo", "Yuichiro", "" ], [ "Nasuno", "Takashi", "" ] ]
We analyze the spin correlations of the top quark pairs produced at Photon Linear Colliders. We employ the circular polarized photon beams and general spin basis for the top quark pair. We consider general spin bases to find a strong spin correlation between produced top quark and anti-top quark. We show the cross-section in these bases and discuss the characteristics of results.
2308.00809
Francesco Giovanni Celiberto
Francesco Giovanni Celiberto, Alessandro Papa
A high-energy QCD portal to exotic matter: Heavy-light tetraquarks at the HL-LHC
11 pages, 5 figures, version published in Physics Letters B. Four novel sets of "TetraQuarks with Heavy and Light Flavors" (TQHL1.0) collinear fragmentation functions released in LHAPDF format and publicly available from https://github.com/FGCeliberto/Collinear_FFs/
Phys. Lett. B 848 (2024), 138406
10.1016/j.physletb.2023.138406
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By taking advantage of the natural stability of the high-energy resummation, recently discovered in the context of heavy-flavor studies, we investigate the inclusive hadroproduction of a neutral heavy-light, hidden-flavored tetraquark ($X_{cu\bar{c}\bar{u}}$ or $X_{bs\bar{b}\bar{s}}$ state), in association with a heavy (single $c$- or $b$-flavored) hadron or a light jet at the (HL-)LHC. We make use of the JETHAD multi-modular working package to provide predictions for rapidity, azimuthal-angle and transverse-momentum distributions calculated via the hybrid high-energy and collinear factorization, where the Balitsky--Fadin--Kuraev--Lipatov resummation of energy logarithms is supplemented by collinear parton densities and fragmentation functions. We rely upon the single-parton fragmentation mechanism, valid in the large transverse-momentum regime, to describe the tetraquark production. Our study represents a first attempt at bridging the gap between all-order calculations of high-energy QCD and the exotics.
[ { "created": "Tue, 1 Aug 2023 19:46:39 GMT", "version": "v1" }, { "created": "Thu, 21 Dec 2023 16:48:34 GMT", "version": "v2" } ]
2023-12-22
[ [ "Celiberto", "Francesco Giovanni", "" ], [ "Papa", "Alessandro", "" ] ]
By taking advantage of the natural stability of the high-energy resummation, recently discovered in the context of heavy-flavor studies, we investigate the inclusive hadroproduction of a neutral heavy-light, hidden-flavored tetraquark ($X_{cu\bar{c}\bar{u}}$ or $X_{bs\bar{b}\bar{s}}$ state), in association with a heavy (single $c$- or $b$-flavored) hadron or a light jet at the (HL-)LHC. We make use of the JETHAD multi-modular working package to provide predictions for rapidity, azimuthal-angle and transverse-momentum distributions calculated via the hybrid high-energy and collinear factorization, where the Balitsky--Fadin--Kuraev--Lipatov resummation of energy logarithms is supplemented by collinear parton densities and fragmentation functions. We rely upon the single-parton fragmentation mechanism, valid in the large transverse-momentum regime, to describe the tetraquark production. Our study represents a first attempt at bridging the gap between all-order calculations of high-energy QCD and the exotics.
1609.02512
Ke-Wei Wei
Ke-Wei Wei, Bing Chen, Na Liu, Qian-Qian Wang, Xin-Heng Guo
Spectroscopy of singly, doubly, and triply bottom baryons
20 pages, 8 tables
Phys. Rev. D 95, 116005 (2017)
10.1103/PhysRevD.95.116005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, some singly bottom baryons have been established experimentally, but none of doubly or triply bottom baryons has been observed. Under the Regge phenomenology, the mass of a ground state unobserved doubly or triply bottom baryon is expressed as a function of masses of the well established light baryons and singly bottom baryons. Then, the values of Regge slopes and Regge intercepts for baryons containing one, two, or three bottom quarks are calculated. After that, masses of the orbitally excited singly, doubly, and triply bottom baryons are estimated. Our predictions may be useful for the discovery of these baryons and the $J^P$ assignment of them.
[ { "created": "Thu, 8 Sep 2016 17:52:17 GMT", "version": "v1" }, { "created": "Fri, 28 Apr 2017 17:57:53 GMT", "version": "v2" } ]
2017-06-21
[ [ "Wei", "Ke-Wei", "" ], [ "Chen", "Bing", "" ], [ "Liu", "Na", "" ], [ "Wang", "Qian-Qian", "" ], [ "Guo", "Xin-Heng", "" ] ]
Recently, some singly bottom baryons have been established experimentally, but none of doubly or triply bottom baryons has been observed. Under the Regge phenomenology, the mass of a ground state unobserved doubly or triply bottom baryon is expressed as a function of masses of the well established light baryons and singly bottom baryons. Then, the values of Regge slopes and Regge intercepts for baryons containing one, two, or three bottom quarks are calculated. After that, masses of the orbitally excited singly, doubly, and triply bottom baryons are estimated. Our predictions may be useful for the discovery of these baryons and the $J^P$ assignment of them.
1408.0973
Sachiko Takeuchi
Sachiko Takeuchi, Kiyotaka Shimizu, and Makoto Takizawa
On the origin of the narrow peak and the isospin symmetry breaking of the $X$(3872)
33 pages, 12 figures
Prog. Theor. Exp. Phys. (2014) 123D01
10.1093/ptep/ptu160
RIKEN-QHP-165
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $X$(3872) formation and decay processes in the $B$-decay are investigated by a $c\bar c$-two-meson hybrid model. The two-meson state consists of the $D^0{\bar D}^*{}^0$, $D^+D^{*-}$, $J/\psi\rho$, and $J/\psi\omega$ channels. The energy-dependent decay widths of the $\rho$ and $\omega$ mesons are introduced. The $D$-${\bar D}^*$ interaction is taken to be consistent with a lack of the $B{\bar B}^*$ bound state. The coupling between the $D{\bar D}^*$ and $J/\psi\rho$ or the $D{\bar D}^*$ and $J/\psi\omega$ channels is obtained from a quark model. The $c{\bar c}$-$D{\bar D}^*$ coupling is taken as a parameter to fit the $X$(3872) mass. The spectrum is calculated up to 4 GeV. It is found that very narrow $J/\psi\rho$ and $J/\psi\omega$ peaks appear around the $D^0{\bar D}^*{}^0$ threshold. The size of the $J/\psi\pi^3$ peak we calculated is 1.29-2.38 times as large as that of the $J/\psi\pi^2$. The isospin symmetry breaking in the present model comes from the mass difference of the charged and neutral $D$ and $D^*$ mesons, which gives a sufficiently large isospin mixing to explain the experiments. It is also found that values of the ratios of the transfer strengths can give the information on the $X$(3872) mass or the size of the $c{\bar c}$-$D{\bar D}^*$ coupling.
[ { "created": "Tue, 5 Aug 2014 13:59:41 GMT", "version": "v1" }, { "created": "Sat, 16 Aug 2014 06:32:11 GMT", "version": "v2" }, { "created": "Tue, 28 Oct 2014 03:38:36 GMT", "version": "v3" }, { "created": "Tue, 12 May 2015 00:55:24 GMT", "version": "v4" } ]
2015-05-13
[ [ "Takeuchi", "Sachiko", "" ], [ "Shimizu", "Kiyotaka", "" ], [ "Takizawa", "Makoto", "" ] ]
The $X$(3872) formation and decay processes in the $B$-decay are investigated by a $c\bar c$-two-meson hybrid model. The two-meson state consists of the $D^0{\bar D}^*{}^0$, $D^+D^{*-}$, $J/\psi\rho$, and $J/\psi\omega$ channels. The energy-dependent decay widths of the $\rho$ and $\omega$ mesons are introduced. The $D$-${\bar D}^*$ interaction is taken to be consistent with a lack of the $B{\bar B}^*$ bound state. The coupling between the $D{\bar D}^*$ and $J/\psi\rho$ or the $D{\bar D}^*$ and $J/\psi\omega$ channels is obtained from a quark model. The $c{\bar c}$-$D{\bar D}^*$ coupling is taken as a parameter to fit the $X$(3872) mass. The spectrum is calculated up to 4 GeV. It is found that very narrow $J/\psi\rho$ and $J/\psi\omega$ peaks appear around the $D^0{\bar D}^*{}^0$ threshold. The size of the $J/\psi\pi^3$ peak we calculated is 1.29-2.38 times as large as that of the $J/\psi\pi^2$. The isospin symmetry breaking in the present model comes from the mass difference of the charged and neutral $D$ and $D^*$ mesons, which gives a sufficiently large isospin mixing to explain the experiments. It is also found that values of the ratios of the transfer strengths can give the information on the $X$(3872) mass or the size of the $c{\bar c}$-$D{\bar D}^*$ coupling.
1510.01691
Marc-Andr\'e Pleier
Jacob Searcy, Lillian Huang, Marc-Andr\'e Pleier, Junjie Zhu
Determination of the $WW$ polarization fractions in $pp \to W^\pm W^\pm jj$ using a deep machine learning technique
7 pages, 4 figures, published in PRD
Phys. Rev. D 93, 094033 (2016)
10.1103/PhysRevD.93.094033
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The unitarization of the longitudinal vector boson scattering (VBS) cross section by the Higgs boson is a fundamental prediction of the Standard Model which has not been experimentally verified. One of the most promising ways to measure VBS uses events containing two leptonically-decaying same-electric-charge $W$ bosons produced in association with two jets. However, the angular distributions of the leptons in the $W$ boson rest frame, which are commonly used to fit polarization fractions, are not readily available in this process due to the presence of two neutrinos in the final state. In this paper we present a method to alleviate this problem by using a deep machine learning technique to recover these angular distributions from measurable event kinematics and demonstrate how the longitudinal-longitudinal scattering fraction could be studied. We show that this method doubles the expected sensitivity when compared to previous proposals.
[ { "created": "Tue, 6 Oct 2015 18:34:01 GMT", "version": "v1" }, { "created": "Tue, 31 May 2016 15:11:31 GMT", "version": "v2" } ]
2016-06-01
[ [ "Searcy", "Jacob", "" ], [ "Huang", "Lillian", "" ], [ "Pleier", "Marc-André", "" ], [ "Zhu", "Junjie", "" ] ]
The unitarization of the longitudinal vector boson scattering (VBS) cross section by the Higgs boson is a fundamental prediction of the Standard Model which has not been experimentally verified. One of the most promising ways to measure VBS uses events containing two leptonically-decaying same-electric-charge $W$ bosons produced in association with two jets. However, the angular distributions of the leptons in the $W$ boson rest frame, which are commonly used to fit polarization fractions, are not readily available in this process due to the presence of two neutrinos in the final state. In this paper we present a method to alleviate this problem by using a deep machine learning technique to recover these angular distributions from measurable event kinematics and demonstrate how the longitudinal-longitudinal scattering fraction could be studied. We show that this method doubles the expected sensitivity when compared to previous proposals.
hep-ph/0609052
Anibal Medina
Anibal D. Medina and Carlos E. M. Wagner
Soft Leptogenesis in Warped Extra Dimensions
22 pages and 1 figure; added references for section 1
JHEP 0612:037,2006
10.1088/1126-6708/2006/12/037
ANL-HEP-PR-06-55, EFI-06-10
hep-ph
null
We implement soft leptogenesis in a warped five dimensional scenario with two branes on the orbifold boundaries coming from an S^{1}/Z_{2} symmetry, and supersymmetry broken on the IR brane. The SM hypermultiplet fields (fermions and Higgs) live in the UV brane and we allow the vector supermultiplets corresponding to the gauge bosons and a hypermultiplet corresponding to the right handed neutrino to live in the bulk. We assume that there are Majorana mass terms for the right handed neutrino superfield fixed on each brane and that there is a Yukawa term involving the right handed neutrino, the left handed neutrino and the Higgs fixed on the UV brane. Supersymmetry is broken by a constant ``superpotential'' on the IR brane, which induces an F-term for the radion hypermultiplet. This F-term leads to a B-term for the right handed sneutrinos as well as a soft SUSY breaking gaugino mass in the 4D theory for the zero modes. The gaugino mass naturally induces an A-term for the right handed sneutrino, left handed sneutrino and the Higgs to be formed through gaugino mediation with a non-trivial CP violating phase. Moreover, we show that within the context of extra dimensions, the condition of out-of-equilibrium decay and the phenomenological constraints on the neutrino mass are both satisfied in a natural way, for UV Majorana masses of the order of the fundamental scale of the theory. Thus all necessary elements for soft leptogenesis are at hand and we are able to predict a correct value for the baryon asymmetry.
[ { "created": "Tue, 5 Sep 2006 21:12:11 GMT", "version": "v1" }, { "created": "Wed, 20 Sep 2006 13:45:57 GMT", "version": "v2" } ]
2009-10-07
[ [ "Medina", "Anibal D.", "" ], [ "Wagner", "Carlos E. M.", "" ] ]
We implement soft leptogenesis in a warped five dimensional scenario with two branes on the orbifold boundaries coming from an S^{1}/Z_{2} symmetry, and supersymmetry broken on the IR brane. The SM hypermultiplet fields (fermions and Higgs) live in the UV brane and we allow the vector supermultiplets corresponding to the gauge bosons and a hypermultiplet corresponding to the right handed neutrino to live in the bulk. We assume that there are Majorana mass terms for the right handed neutrino superfield fixed on each brane and that there is a Yukawa term involving the right handed neutrino, the left handed neutrino and the Higgs fixed on the UV brane. Supersymmetry is broken by a constant ``superpotential'' on the IR brane, which induces an F-term for the radion hypermultiplet. This F-term leads to a B-term for the right handed sneutrinos as well as a soft SUSY breaking gaugino mass in the 4D theory for the zero modes. The gaugino mass naturally induces an A-term for the right handed sneutrino, left handed sneutrino and the Higgs to be formed through gaugino mediation with a non-trivial CP violating phase. Moreover, we show that within the context of extra dimensions, the condition of out-of-equilibrium decay and the phenomenological constraints on the neutrino mass are both satisfied in a natural way, for UV Majorana masses of the order of the fundamental scale of the theory. Thus all necessary elements for soft leptogenesis are at hand and we are able to predict a correct value for the baryon asymmetry.
hep-ph/0605211
Miguel Nebot
E. Alvarez, J. Bernabeu (Valencia U. & Valencia U., IFIC), M. Nebot (Lisbon, IST)
$\Delta t$-dependent equal-sign dilepton asymmetry and CPTV effects in the symmetry of the $B^0$--$\bar B^0$ entangled state
19 pages, 11 figures; minor changes, additional and updated references
JHEP 0611 (2006) 087
10.1088/1126-6708/2006/11/087
IFIC/06-15
hep-ph hep-ex
null
In this paper we discuss experimental consequences of a novel kind of CPT violation which would manifest itself in the symmetry of the entangled initial state of $B ^0$ and $\bar B ^0$ through their loss of indistinguishability. The ``wrong'' symmetry component is proportional to $\omega$. We focus our theoretical study on the $\Delta t$-dependence of observables concerning equal-sign dilepton events for which the intensity vanishes at $\Delta t = 0$ in absence of $\omega$. We find that the charge asymmetry, $A_{sl}$, acquires a $\Delta t$-dependence linear in $\omega$, whose relative importance appears on specific regions of time still unexplored. We also do a statistical analysis for the measurements here proposed and find a high sensitivity to this new CPT-violating effect in this charge asymmetry. We obtain the first limits on the $\omega$-effect by re-analyzing existing data on the $A_{sl}$ asymmetry.
[ { "created": "Fri, 19 May 2006 10:21:23 GMT", "version": "v1" }, { "created": "Wed, 29 Nov 2006 12:12:20 GMT", "version": "v2" } ]
2009-11-11
[ [ "Alvarez", "E.", "", "Valencia U. & Valencia U., IFIC" ], [ "Bernabeu", "J.", "", "Valencia U. & Valencia U., IFIC" ], [ "Nebot", "M.", "", "Lisbon, IST" ] ]
In this paper we discuss experimental consequences of a novel kind of CPT violation which would manifest itself in the symmetry of the entangled initial state of $B ^0$ and $\bar B ^0$ through their loss of indistinguishability. The ``wrong'' symmetry component is proportional to $\omega$. We focus our theoretical study on the $\Delta t$-dependence of observables concerning equal-sign dilepton events for which the intensity vanishes at $\Delta t = 0$ in absence of $\omega$. We find that the charge asymmetry, $A_{sl}$, acquires a $\Delta t$-dependence linear in $\omega$, whose relative importance appears on specific regions of time still unexplored. We also do a statistical analysis for the measurements here proposed and find a high sensitivity to this new CPT-violating effect in this charge asymmetry. We obtain the first limits on the $\omega$-effect by re-analyzing existing data on the $A_{sl}$ asymmetry.
hep-ph/0210076
Stefano Capitani
Stefano Capitani
Perturbative and Non-perturbative Lattice Calculations for the Study of Parton Distributions
6 pages. Talk presented at the 6th International Symposium on Radiative Corrections "RADCOR 2002" and 6th Zeuthen Workshop on Elementary Particle Theory "Loops and Legs 2002", Kloster Banz (Germany), September 8 to 13, 2002
Nucl.Phys.Proc.Suppl. 116 (2003) 115-120
10.1016/S0920-5632(03)80154-8
DESY 02-161
hep-ph hep-lat
null
We discuss how lattice calculations can be a useful tool for the study of structure functions. Particular emphasis is given to the perturbative renormalization of the operators.
[ { "created": "Fri, 4 Oct 2002 13:03:13 GMT", "version": "v1" } ]
2009-11-07
[ [ "Capitani", "Stefano", "" ] ]
We discuss how lattice calculations can be a useful tool for the study of structure functions. Particular emphasis is given to the perturbative renormalization of the operators.
1101.5965
Carl E. Carlson
Carl E. Carlson (Helmholtz Institut Mainz, and William and Mary) and Marc Vanderhaeghen (U. Mainz)
Higher order proton structure corrections to the Lamb shift in muonic hydrogen
4 pages, 3 figures
null
10.1103/PhysRevA.84.020102
MKPH-T-11-03
hep-ph nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent conundrum with the proton charge radius inspires reconsideration of the corrections that enter into determinations of the proton size. We study the two-photon proton-structure corrections, with special consideration of the non-pole subtraction term in the dispersion relation, and using fits to modern data to evaluate the energy contributions. We find that individual contributions change more than the total, and present results with error estimates.
[ { "created": "Mon, 31 Jan 2011 13:45:35 GMT", "version": "v1" } ]
2013-05-29
[ [ "Carlson", "Carl E.", "", "Helmholtz Institut Mainz, and William and Mary" ], [ "Vanderhaeghen", "Marc", "", "U. Mainz" ] ]
The recent conundrum with the proton charge radius inspires reconsideration of the corrections that enter into determinations of the proton size. We study the two-photon proton-structure corrections, with special consideration of the non-pole subtraction term in the dispersion relation, and using fits to modern data to evaluate the energy contributions. We find that individual contributions change more than the total, and present results with error estimates.
hep-ph/0306086
Cheng Jian-Feng
Jian-Feng Cheng, Chao-Shang Huang and Xiao-hong Wu
Neutral Higgs boson contributions to CP asymmetry of $B \to \Phi K_S$ in MSSM
7 pages and 6 figures
Phys.Lett.B585:287-294,2004
10.1016/j.physletb.2004.01.068
null
hep-ph
null
We have studied the neutral Higgs boson (NHB) contributions to the pure penguin process $B\to \phi K_S$ in MSSM with middle and large $\tan\beta$ (say, $>$ 8). We show that the $\alpha_s$ order hadronic matrix elements of NHB induced operators can make sizable effects on both the branch ratio and time dependent CP asymmetry $S_{\phi K}$. Under the all relevant experimental constraints, the Higgs mediated contributions to $S_{\phi K}$ alone can provide a significant deviation from SM and, in particular, lead to a negative $S_{\phi K}$ which is reported by BaBar and Belle.
[ { "created": "Wed, 11 Jun 2003 04:07:26 GMT", "version": "v1" }, { "created": "Mon, 8 Dec 2003 04:05:43 GMT", "version": "v2" } ]
2011-03-23
[ [ "Cheng", "Jian-Feng", "" ], [ "Huang", "Chao-Shang", "" ], [ "Wu", "Xiao-hong", "" ] ]
We have studied the neutral Higgs boson (NHB) contributions to the pure penguin process $B\to \phi K_S$ in MSSM with middle and large $\tan\beta$ (say, $>$ 8). We show that the $\alpha_s$ order hadronic matrix elements of NHB induced operators can make sizable effects on both the branch ratio and time dependent CP asymmetry $S_{\phi K}$. Under the all relevant experimental constraints, the Higgs mediated contributions to $S_{\phi K}$ alone can provide a significant deviation from SM and, in particular, lead to a negative $S_{\phi K}$ which is reported by BaBar and Belle.
2106.04576
Abdel Magied Diab
Abdel Nasser Tawfik (Egyptian Ctr. Theor. Phys., Cairo and Goethe U., Frankfurt (main)), Abdel Magied Diab (MUTI, Cairo)
Chiral magnetic properties of QCD phase-diagram
16 pages, 11 figures, the paper is accepted for publication in The European Physical Journal A (EPJA)
Eur. Phys. J. A (2021) 57: 200
10.1140/epja/s10050-021-00501-z
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The QCD phase diagram is studied, at finite magnetic field. Our calculations are based on the QCD effective model, the SU($3$) Polyakov linear sigma model (PLSM), in which the chiral symmetry is integrated in the hadron phase and in the parton phase, the up-, down- and strange-quark degrees of freedom are incorporated besides the inclusion of Polyakov loop potentials in the pure gauge limit, which are motivated by various underlying QCD symmetries. The Landau quantization and the magnetic catalysis are implemented. The response of the QCD matter to an external magnetic field such as magnetization, magnetic susceptibility and permeability has been estimated. We conclude that the parton phase has higher values of magnetization, magnetic susceptibility, and permeability relative to the hadron phase. Depending on the contributions to the Landau levels, we conclude that the chiral magnetic field enhances the chiral quark condensates and hence the chiral QCD phase diagram, i.e. the hadron-parton phase transition likely takes place, at lower critical temperatures and chemical potentials.
[ { "created": "Tue, 8 Jun 2021 12:57:54 GMT", "version": "v1" } ]
2021-07-05
[ [ "Tawfik", "Abdel Nasser", "", "Egyptian Ctr. Theor. Phys., Cairo and Goethe U.,\n Frankfurt" ], [ "Diab", "Abdel Magied", "", "MUTI, Cairo" ] ]
The QCD phase diagram is studied, at finite magnetic field. Our calculations are based on the QCD effective model, the SU($3$) Polyakov linear sigma model (PLSM), in which the chiral symmetry is integrated in the hadron phase and in the parton phase, the up-, down- and strange-quark degrees of freedom are incorporated besides the inclusion of Polyakov loop potentials in the pure gauge limit, which are motivated by various underlying QCD symmetries. The Landau quantization and the magnetic catalysis are implemented. The response of the QCD matter to an external magnetic field such as magnetization, magnetic susceptibility and permeability has been estimated. We conclude that the parton phase has higher values of magnetization, magnetic susceptibility, and permeability relative to the hadron phase. Depending on the contributions to the Landau levels, we conclude that the chiral magnetic field enhances the chiral quark condensates and hence the chiral QCD phase diagram, i.e. the hadron-parton phase transition likely takes place, at lower critical temperatures and chemical potentials.
1303.4583
Raghavendra Hundi
R. S. Hundi
Implications of Higgs to diphoton decay rate in the bilinear R-parity violating supersymmetric model
23 pages, 10 eps figures, minor changes, new references added, accepted by Physical Review D
null
10.1103/PhysRevD.87.115005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Large Hadron Collider has recently discovered a Higgs-like particle having a mass around 125 GeV and also indicated that there is an enhancement in the Higgs to diphoton decay rate as compared to that in the standard model. We have studied implications of these discoveries in the bilinear R-parity violating supersymmetric model, whose main motivation is to explain the non-zero masses for neutrinos. The R-parity violating parameters in this model are $\epsilon$ and $b_\epsilon$, and these parameters determine the scale of neutrino masses. If the enhancement in the Higgs to diphoton decay rate is true, then we have found $\epsilon\gapprox 0.01$ GeV and $b_\epsilon\sim$ 1 GeV$^2$ in order to be compatible with the neutrino oscillation data. Also, in the above mentioned analysis, we can determine the soft masses of sleptons ($m_L$) and CP-odd Higgs boson mass ($m_A$). We have estimated that $m_L\gapprox$ 300 GeV and $m_A\gapprox$ 700 GeV. We have also commented on the allowed values of $\epsilon$ and $b_\epsilon$, in case there is no enhancement in the Higgs to diphoton decay rate. Finally, we present a model to explain the smallness of $\epsilon$ and $b_\epsilon$.
[ { "created": "Tue, 19 Mar 2013 13:21:07 GMT", "version": "v1" }, { "created": "Thu, 23 May 2013 13:25:23 GMT", "version": "v2" } ]
2013-06-12
[ [ "Hundi", "R. S.", "" ] ]
The Large Hadron Collider has recently discovered a Higgs-like particle having a mass around 125 GeV and also indicated that there is an enhancement in the Higgs to diphoton decay rate as compared to that in the standard model. We have studied implications of these discoveries in the bilinear R-parity violating supersymmetric model, whose main motivation is to explain the non-zero masses for neutrinos. The R-parity violating parameters in this model are $\epsilon$ and $b_\epsilon$, and these parameters determine the scale of neutrino masses. If the enhancement in the Higgs to diphoton decay rate is true, then we have found $\epsilon\gapprox 0.01$ GeV and $b_\epsilon\sim$ 1 GeV$^2$ in order to be compatible with the neutrino oscillation data. Also, in the above mentioned analysis, we can determine the soft masses of sleptons ($m_L$) and CP-odd Higgs boson mass ($m_A$). We have estimated that $m_L\gapprox$ 300 GeV and $m_A\gapprox$ 700 GeV. We have also commented on the allowed values of $\epsilon$ and $b_\epsilon$, in case there is no enhancement in the Higgs to diphoton decay rate. Finally, we present a model to explain the smallness of $\epsilon$ and $b_\epsilon$.
hep-ph/9506428
Bob Holdom
B. Holdom
New third-family flavor physics and the top mass
Invited talk given at the Top Quark Workshop, Iowa State University, May 25-26, 1995, 6 pages, uuencoded postscript
null
null
UTPT-95-13
hep-ph
null
A new massive gauge boson (X) coupling to the third family produces a tantalizing pattern of deviations away from the standard model. These include increasing Gamma_b/Gamma_h and decreasing the alpha_s(M_Z) extracted from Gamma_h/Gamma_ell. We indicate how the X boson may be related to a dynamical origin of the top mass.
[ { "created": "Tue, 27 Jun 1995 03:03:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Holdom", "B.", "" ] ]
A new massive gauge boson (X) coupling to the third family produces a tantalizing pattern of deviations away from the standard model. These include increasing Gamma_b/Gamma_h and decreasing the alpha_s(M_Z) extracted from Gamma_h/Gamma_ell. We indicate how the X boson may be related to a dynamical origin of the top mass.
1404.5577
M\'arcio Ferreira
M. Ferreira, P. Costa, O. Louren\c{c}o, T. Frederico, and C. Provid\^encia
Inverse magnetic catalysis in the (2+1)-flavor Nambu--Jona-Lasinio and Polyakov--Nambu--Jona-Lasinio models
9 pages,12 figures; PRD version
Phys. Rev. D 89, 116011 (2014)
10.1103/PhysRevD.89.116011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The QCD phase diagram at zero chemical potential and finite temperature subject to an external magnetic field is studied within the three flavor Nambu--Jona-Lasinio (NJL) model and the NJL model with the Polyakov loop (PNJL). A scalar coupling parameter dependent on the magnetic field intensity is considered. The scalar coupling has been fitted so that the lattice QCD pseudocritical chiral transition temperatures are reproduced and in the limit of large magnetic field decreases with the inverse of the magnetic field intensity. This dependence of the coupling allows to reproduce the lattice QCD results with respect to the quark condensates and Polyakov loop: due to the magnetic field the quark condensates are enhanced at low and high temperatures and suppressed for temperatures close to the transition temperatures and the Polyakov loop increases with the magnetic field.
[ { "created": "Tue, 22 Apr 2014 18:03:28 GMT", "version": "v1" }, { "created": "Fri, 20 Jun 2014 20:29:47 GMT", "version": "v2" } ]
2014-06-25
[ [ "Ferreira", "M.", "" ], [ "Costa", "P.", "" ], [ "Lourenço", "O.", "" ], [ "Frederico", "T.", "" ], [ "Providência", "C.", "" ] ]
The QCD phase diagram at zero chemical potential and finite temperature subject to an external magnetic field is studied within the three flavor Nambu--Jona-Lasinio (NJL) model and the NJL model with the Polyakov loop (PNJL). A scalar coupling parameter dependent on the magnetic field intensity is considered. The scalar coupling has been fitted so that the lattice QCD pseudocritical chiral transition temperatures are reproduced and in the limit of large magnetic field decreases with the inverse of the magnetic field intensity. This dependence of the coupling allows to reproduce the lattice QCD results with respect to the quark condensates and Polyakov loop: due to the magnetic field the quark condensates are enhanced at low and high temperatures and suppressed for temperatures close to the transition temperatures and the Polyakov loop increases with the magnetic field.
1103.2362
James Maxin
Tianjun Li, James A. Maxin, Dimitri V. Nanopoulos, and Joel W. Walker
Ultra High Jet Signals from Stringy No-Scale Supergravity
4 pages, 2 figures, 2 tables
null
null
null
hep-ph astro-ph.CO hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present distinctive signatures of flipped F-Theory models with TeV-scale vector-like particles, a \sqrt{s} = 7 TeV 1 fb^{-1} test at LHC of a class of models well-motivated from string theory. The characteristic feature is a light stop and gluino, both sparticles lighter than all other squarks. This unique aspect of the supersymmetry spectrum generates an ultra-high multiplicity of hadronic jets. We find the optimal signal to background ratio is realized for 9 or more jets. Exclusion of the essential cuts presented here could leave the ultra-high jet signal severely attenuated and concealed.
[ { "created": "Fri, 11 Mar 2011 20:37:45 GMT", "version": "v1" } ]
2015-03-19
[ [ "Li", "Tianjun", "" ], [ "Maxin", "James A.", "" ], [ "Nanopoulos", "Dimitri V.", "" ], [ "Walker", "Joel W.", "" ] ]
We present distinctive signatures of flipped F-Theory models with TeV-scale vector-like particles, a \sqrt{s} = 7 TeV 1 fb^{-1} test at LHC of a class of models well-motivated from string theory. The characteristic feature is a light stop and gluino, both sparticles lighter than all other squarks. This unique aspect of the supersymmetry spectrum generates an ultra-high multiplicity of hadronic jets. We find the optimal signal to background ratio is realized for 9 or more jets. Exclusion of the essential cuts presented here could leave the ultra-high jet signal severely attenuated and concealed.
hep-ph/0112336
Gi-Chol Cho
Gi-Chol Cho, Etsuko Izumi and Akio Sugamoto (Ochanomizu U.)
CERN LEP2 constraint on 4D QED having dynamically generated spatial dimension
16 pages, latex2e, 5 figures. Version to appear in Phys.Rev.D
Phys.Rev. D66 (2002) 116009
10.1103/PhysRevD.66.116009
OCHA-PP-184
hep-ph
null
We study 4D QED in which one spatial dimension is dynamically generated from 3D action, following the mechanism proposed by Arkani-Hamed, Cohen and Georgi. In this model, the generated fourth dimension is discretized by an interval parameter $a$. We examine the phenomenological constraint on the parameter $a$ coming from the collider experiments on the QED process $e^+ e^- \to \gamma \gamma$. It is found that the LEP2 experiments give the constraint of $1/a \simgt 461\gev$. Expected bound on the same parameter $a$ at the future $e^+ e^-$ linear collider is briefly discussed.
[ { "created": "Thu, 27 Dec 2001 08:54:51 GMT", "version": "v1" }, { "created": "Wed, 20 Feb 2002 07:58:39 GMT", "version": "v2" }, { "created": "Thu, 7 Nov 2002 11:05:18 GMT", "version": "v3" } ]
2009-11-07
[ [ "Cho", "Gi-Chol", "", "Ochanomizu U." ], [ "Izumi", "Etsuko", "", "Ochanomizu U." ], [ "Sugamoto", "Akio", "", "Ochanomizu U." ] ]
We study 4D QED in which one spatial dimension is dynamically generated from 3D action, following the mechanism proposed by Arkani-Hamed, Cohen and Georgi. In this model, the generated fourth dimension is discretized by an interval parameter $a$. We examine the phenomenological constraint on the parameter $a$ coming from the collider experiments on the QED process $e^+ e^- \to \gamma \gamma$. It is found that the LEP2 experiments give the constraint of $1/a \simgt 461\gev$. Expected bound on the same parameter $a$ at the future $e^+ e^-$ linear collider is briefly discussed.
hep-ph/9402298
Geert Jan van Oldenborgh
Geert Jan van Oldenborgh, Paula. J. Franzini and Arianna Borrelli
WWF: a generator for e+e- to 4 fermions + gamma
13 pages incl 2 figures, latex+axodraw, full ps file available as ftp://pss058.psi.ch/pub/preprints/wwf.ps, PSI-PR-94-06
Comput.Phys.Commun. 83 (1994) 14-22
10.1016/0010-4655(94)90031-0
null
hep-ph
null
We present an efficient generator for the process e+e- to 4 fermions + gamma through off-shell W pairs. It is based on a massless matrix element with leading order(m^2) corrections. Only the resonant WW graphs are included. We have tested it against a matrix element without these approximations and found agreement to within ~1% at LEPII energies.
[ { "created": "Wed, 16 Feb 1994 21:23:41 GMT", "version": "v1" } ]
2009-10-28
[ [ "van Oldenborgh", "Geert Jan", "" ], [ "Franzini", "Paula. J.", "" ], [ "Borrelli", "Arianna", "" ] ]
We present an efficient generator for the process e+e- to 4 fermions + gamma through off-shell W pairs. It is based on a massless matrix element with leading order(m^2) corrections. Only the resonant WW graphs are included. We have tested it against a matrix element without these approximations and found agreement to within ~1% at LEPII energies.
1201.4816
Kwang Sik Jeong
Kwang Sik Jeong, Fuminobu Takahashi
Light Higgsino from Axion Dark Radiation
18 pages, 1 figure; published in JHEP
null
10.1007/JHEP08(2012)017
TU-899; IPMU12-0010
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent observations imply that there is an extra relativistic degree of freedom coined dark radiation. We argue that the QCD axion is a plausible candidate for the dark radiation, not only because of its extremely small mass, but also because in the supersymmetric extension of the Peccei-Quinn mechanism the saxion tends to dominate the Universe and decays into axions with a sizable branching fraction. We show that the Higgsino mixing parameter mu is bounded from above when the axions produced at the saxion decays constitute the dark radiation: mu \lesssim 300 GeV for a saxion lighter than 2m_W, and mu less than the saxion mass otherwise. Interestingly, the Higgsino can be light enough to be within the reach of LHC and/or ILC even when the other superparticles are heavy with mass about 1 TeV or higher. We also estimate the abundance of axino produced by the decays of Higgsino and saxion.
[ { "created": "Mon, 23 Jan 2012 19:09:50 GMT", "version": "v1" }, { "created": "Thu, 9 Feb 2012 13:05:11 GMT", "version": "v2" }, { "created": "Mon, 20 Aug 2012 15:02:49 GMT", "version": "v3" } ]
2015-06-03
[ [ "Jeong", "Kwang Sik", "" ], [ "Takahashi", "Fuminobu", "" ] ]
The recent observations imply that there is an extra relativistic degree of freedom coined dark radiation. We argue that the QCD axion is a plausible candidate for the dark radiation, not only because of its extremely small mass, but also because in the supersymmetric extension of the Peccei-Quinn mechanism the saxion tends to dominate the Universe and decays into axions with a sizable branching fraction. We show that the Higgsino mixing parameter mu is bounded from above when the axions produced at the saxion decays constitute the dark radiation: mu \lesssim 300 GeV for a saxion lighter than 2m_W, and mu less than the saxion mass otherwise. Interestingly, the Higgsino can be light enough to be within the reach of LHC and/or ILC even when the other superparticles are heavy with mass about 1 TeV or higher. We also estimate the abundance of axino produced by the decays of Higgsino and saxion.
2405.08591
Shao-Feng Ge
Xuan-Ye Fu and Shao-Feng Ge and Zi-Yang Guo and Qi-Heng Wang
Degeneracy Enhancement of Neutron-Antineutron Oscillation in Neutron Star
6 pages, 3 figures
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the fermion oscillation in a degenerate environment. The direct consequence is introducing a Pauli blocking factor $1 - f_i$, where $f_i$ is the phase space distribution function, for each intermediate mass eigenstate during propagation. It is then much easier for a state with larger existing fraction or density to oscillate into other states with less degeneracy while the reversed process is not enhanced. This can significantly modify the oscillation behaviors. We apply this degenerate fermion oscillation to a concrete scenario of neutron-antineutron oscillation in neutron star. It turns out antineutrons receive a standing fraction to annihilate with the environmental neutrons. The subsequent neutron star heating can put an extremely stringent bound on the baryon number violating cross mass term between neutron and antineutron.
[ { "created": "Tue, 14 May 2024 13:31:46 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2024 09:03:39 GMT", "version": "v2" } ]
2024-08-09
[ [ "Fu", "Xuan-Ye", "" ], [ "Ge", "Shao-Feng", "" ], [ "Guo", "Zi-Yang", "" ], [ "Wang", "Qi-Heng", "" ] ]
We explore the fermion oscillation in a degenerate environment. The direct consequence is introducing a Pauli blocking factor $1 - f_i$, where $f_i$ is the phase space distribution function, for each intermediate mass eigenstate during propagation. It is then much easier for a state with larger existing fraction or density to oscillate into other states with less degeneracy while the reversed process is not enhanced. This can significantly modify the oscillation behaviors. We apply this degenerate fermion oscillation to a concrete scenario of neutron-antineutron oscillation in neutron star. It turns out antineutrons receive a standing fraction to annihilate with the environmental neutrons. The subsequent neutron star heating can put an extremely stringent bound on the baryon number violating cross mass term between neutron and antineutron.
1812.10965
Renat Sadykov
S. Bondarenko, Ya. Dydyshka, L. Kalinovskaya, L. Rumyantsev, R. Sadykov, V. Yermolchyk
One-loop electroweak radiative corrections to polarized $e^+e^- \to ZH$
10 pages, 1 figure
Phys. Rev. D 100, 073002 (2019)
10.1103/PhysRevD.100.073002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The paper describes high-precision theoretical predictions obtained for the cross sections of the process $e^+e^- \to ZH$ for future electron-positron colliders. The calculations performed using the SANC platform taking into account the full contribution of one-loop electroweak radiative corrections, as well as longitudinal polarization of the initial beams. Numerical results are given for the energy range $E_{cm}=250$ GeV - $1000$ GeV with various polarization degrees.
[ { "created": "Fri, 28 Dec 2018 12:07:26 GMT", "version": "v1" } ]
2019-10-09
[ [ "Bondarenko", "S.", "" ], [ "Dydyshka", "Ya.", "" ], [ "Kalinovskaya", "L.", "" ], [ "Rumyantsev", "L.", "" ], [ "Sadykov", "R.", "" ], [ "Yermolchyk", "V.", "" ] ]
The paper describes high-precision theoretical predictions obtained for the cross sections of the process $e^+e^- \to ZH$ for future electron-positron colliders. The calculations performed using the SANC platform taking into account the full contribution of one-loop electroweak radiative corrections, as well as longitudinal polarization of the initial beams. Numerical results are given for the energy range $E_{cm}=250$ GeV - $1000$ GeV with various polarization degrees.
1403.2450
Antonino Di Piazza
Norman Neitz and Antonino Di Piazza
Electron-beam dynamics in a strong laser field including quantum radiation reaction
25 pages, 11 figures
Phys. Rev. A vol. 90, 022102 (2014)
10.1103/PhysRevA.90.022102
null
hep-ph physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The evolution of an electron beam colliding head-on with a strong plane-wave field is investigated in the framework of strong-field QED including radiation-reaction effects due to photon emission. Employing a kinetic approach to describe the electron and the photon distribution it is shown that at a given total laser fluence the final electron distribution depends on the shape of the laser envelope and on the pulse duration, in contrast to the classical predictions of radiation reaction based on the Landau-Lifshitz equation. Finally, it is investigated how the pair-creation process leads to a nonlinear coupled evolution of the electrons in the beam, of the produced charged particles, and of the emitted photons.
[ { "created": "Tue, 11 Mar 2014 00:57:16 GMT", "version": "v1" }, { "created": "Wed, 16 Apr 2014 16:38:03 GMT", "version": "v2" }, { "created": "Wed, 6 Aug 2014 12:09:54 GMT", "version": "v3" } ]
2014-08-07
[ [ "Neitz", "Norman", "" ], [ "Di Piazza", "Antonino", "" ] ]
The evolution of an electron beam colliding head-on with a strong plane-wave field is investigated in the framework of strong-field QED including radiation-reaction effects due to photon emission. Employing a kinetic approach to describe the electron and the photon distribution it is shown that at a given total laser fluence the final electron distribution depends on the shape of the laser envelope and on the pulse duration, in contrast to the classical predictions of radiation reaction based on the Landau-Lifshitz equation. Finally, it is investigated how the pair-creation process leads to a nonlinear coupled evolution of the electrons in the beam, of the produced charged particles, and of the emitted photons.
hep-ph/0509069
Carl A. Gagliardi
C. A. Gagliardi, R. E. Tribble, N. J. Williams
Global analysis of muon decay measurements
5 pages, 3 tables
Phys.Rev. D72 (2005) 073002
10.1103/PhysRevD.72.073002
null
hep-ph
null
We have performed a global analysis of muon decay measurements to establish model-independent limits on the space-time structure of the muon decay matrix element. We find limits on the scalar, vector and tensor coupling of right- and left-handed muons to right- and left-handed electrons. The limits on those terms that involve the decay of right-handed muons to left-handed electrons are more restrictive than in previous global analyses, while the limits on the other non-standard model interactions are comparable. The value of the Michel parameter eta found in the global analysis is -0.0036 \pm 0.0069, slightly more precise than the value found in a more restrictive analysis of a recent measurement. This has implications for the Fermi coupling constant G_F.
[ { "created": "Wed, 7 Sep 2005 16:48:24 GMT", "version": "v1" } ]
2009-11-11
[ [ "Gagliardi", "C. A.", "" ], [ "Tribble", "R. E.", "" ], [ "Williams", "N. J.", "" ] ]
We have performed a global analysis of muon decay measurements to establish model-independent limits on the space-time structure of the muon decay matrix element. We find limits on the scalar, vector and tensor coupling of right- and left-handed muons to right- and left-handed electrons. The limits on those terms that involve the decay of right-handed muons to left-handed electrons are more restrictive than in previous global analyses, while the limits on the other non-standard model interactions are comparable. The value of the Michel parameter eta found in the global analysis is -0.0036 \pm 0.0069, slightly more precise than the value found in a more restrictive analysis of a recent measurement. This has implications for the Fermi coupling constant G_F.
hep-ph/9706394
Xin-heng Guo
X.-H. Guo and T. Muta
Isgur-Wise Function for $\Lambda_b \to \Lambda_c$ in B-S Approach
14 pages, 4 Postscript figures
Phys.Rev. D54 (1996) 4629-4634
10.1103/PhysRevD.54.4629
HUPD-9610
hep-ph
null
In the heavy quark limit, the heavy baryon $\Lambda_Q$ (Q=b or c) can be regarded as composed of a heavy quark and a scalar light diquark which has good spin and flavor quantum numbers. Based on this picture we establish the Bethe-Salpeter (B-S) equation for $\Lambda_Q$ in the leading order of $1/m_Q$ expansion. With the kernel containing both the scalar confinement and one-gluon-exchange terms we solve the B-S equation numerically. The Isgur-Wise function for $\Lambda_b \to \Lambda_c$ is obtained numerically from our model. Comparison with other model calculations are also presented. It seems that the Isgur-Wise function for $\Lambda_b \to \Lambda_c$ drops faster than that for $B \to D$. The differential and total decay widths for $\Lambda_b \to \Lambda_c l \bar{\nu}$ are given in the limit $m_{b,c}\to \infty$.
[ { "created": "Tue, 17 Jun 1997 23:43:57 GMT", "version": "v1" } ]
2016-09-06
[ [ "Guo", "X. -H.", "" ], [ "Muta", "T.", "" ] ]
In the heavy quark limit, the heavy baryon $\Lambda_Q$ (Q=b or c) can be regarded as composed of a heavy quark and a scalar light diquark which has good spin and flavor quantum numbers. Based on this picture we establish the Bethe-Salpeter (B-S) equation for $\Lambda_Q$ in the leading order of $1/m_Q$ expansion. With the kernel containing both the scalar confinement and one-gluon-exchange terms we solve the B-S equation numerically. The Isgur-Wise function for $\Lambda_b \to \Lambda_c$ is obtained numerically from our model. Comparison with other model calculations are also presented. It seems that the Isgur-Wise function for $\Lambda_b \to \Lambda_c$ drops faster than that for $B \to D$. The differential and total decay widths for $\Lambda_b \to \Lambda_c l \bar{\nu}$ are given in the limit $m_{b,c}\to \infty$.
1503.08176
Nita Sinha
Aritra Biswas, Nita Sinha and Gauhar Abbas
Non-leptonic decays of Charmed mesons into two Pseudoscalars
33 pages, 2 figures, Error in one of the experimental branching ratio corrected and fits redone. Main conclusions remain unaltered, additional concluding statements added, references and acknowledgements updated
Phys. Rev. D 92, 014032 (2015)
10.1103/PhysRevD.92.014032
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the role of resonant coupled channel final state interactions (FSI), as well as weak annihilation and exchange contributions in explaining all the two body hadronic $D\rightarrow PP$ decay modes data. In the un-unitarized amplitudes we include modified Wilson coefficients with non-factorizable corrections as parameters. For the hadronic form factors, the z-series expansion method is used to get the $q^2$ dependence. The FSI effects are incorporated via a phenomenological approach with widths of resonances to various channels taken from observations where available, and others as additional parameters to be determined from fits of all the theoretical rates to the measured ones. Our results for the rather hard to explain $D^0\rightarrow K^+K^-, \pi^+\pi^- $ are in agreement with measured values. We demonstrate that both weak exchange as well as FSI effects are required to get the correct branching ratio for the $D^ \rightarrow K^0\bar{K^0}$ mode. Using our unitarized amplitudes we evaluate the strong phase difference between the amplitudes for $D^0\rightarrow K^-\pi^+$ and $D^0\rightarrow K^+\pi^-$ and find it to be in complete agreement with the recent BES III result.
[ { "created": "Fri, 27 Mar 2015 18:30:51 GMT", "version": "v1" }, { "created": "Mon, 20 Apr 2015 16:25:05 GMT", "version": "v2" } ]
2015-08-05
[ [ "Biswas", "Aritra", "" ], [ "Sinha", "Nita", "" ], [ "Abbas", "Gauhar", "" ] ]
We examine the role of resonant coupled channel final state interactions (FSI), as well as weak annihilation and exchange contributions in explaining all the two body hadronic $D\rightarrow PP$ decay modes data. In the un-unitarized amplitudes we include modified Wilson coefficients with non-factorizable corrections as parameters. For the hadronic form factors, the z-series expansion method is used to get the $q^2$ dependence. The FSI effects are incorporated via a phenomenological approach with widths of resonances to various channels taken from observations where available, and others as additional parameters to be determined from fits of all the theoretical rates to the measured ones. Our results for the rather hard to explain $D^0\rightarrow K^+K^-, \pi^+\pi^- $ are in agreement with measured values. We demonstrate that both weak exchange as well as FSI effects are required to get the correct branching ratio for the $D^ \rightarrow K^0\bar{K^0}$ mode. Using our unitarized amplitudes we evaluate the strong phase difference between the amplitudes for $D^0\rightarrow K^-\pi^+$ and $D^0\rightarrow K^+\pi^-$ and find it to be in complete agreement with the recent BES III result.
2212.03350
Naser Ahmadiniaz
N. Ahmadiniaz, T. E. Cowan, M. Ding, M. A. Lopez Lopez, R. Sauerbrey, R. Shaisultanov and R. Sch\"utzhold
Field-assisted birefringent Compton scattering
6 pages, 2 figures
null
null
null
hep-ph hep-th physics.optics
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by experimental initiatives such as the Helmholtz International Beamline for Extreme Fields (HIBEF), we study Compton scattering of x-rays at electrons in a strong external field (e.g., a strong optical laser) with special emphasis on the polarization-changing (i.e., birefringent) contribution on the amplitude level. Apart from being a potential background process for the planned vacuum birefringence experiments, this effect could be used for diagnostic purposes. Since the birefringent signal from free electrons (i.e., without the external field) vanishes in forward direction, the ratio of the birefringent and the normal (polarization conserving) contribution yields information about the field strength at the interaction point.
[ { "created": "Tue, 6 Dec 2022 22:11:35 GMT", "version": "v1" } ]
2022-12-08
[ [ "Ahmadiniaz", "N.", "" ], [ "Cowan", "T. E.", "" ], [ "Ding", "M.", "" ], [ "Lopez", "M. A. Lopez", "" ], [ "Sauerbrey", "R.", "" ], [ "Shaisultanov", "R.", "" ], [ "Schützhold", "R.", "" ] ]
Motivated by experimental initiatives such as the Helmholtz International Beamline for Extreme Fields (HIBEF), we study Compton scattering of x-rays at electrons in a strong external field (e.g., a strong optical laser) with special emphasis on the polarization-changing (i.e., birefringent) contribution on the amplitude level. Apart from being a potential background process for the planned vacuum birefringence experiments, this effect could be used for diagnostic purposes. Since the birefringent signal from free electrons (i.e., without the external field) vanishes in forward direction, the ratio of the birefringent and the normal (polarization conserving) contribution yields information about the field strength at the interaction point.
1702.07356
Daniel Aloni
Daniel Aloni, Aielet Efrati, Yuval Grossman and Yosef Nir
$\Upsilon$ and $\psi$ leptonic decays as probes of solutions to the $R_D^{(*)}$ puzzle
Version published in JHEP, 17 pages, 7 figures
Journal of High Energy Physics, 2017(6), 1-27
10.1007/JHEP06(2017)019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experimental measurements of the ratios $R(D^{(*)})\equiv\frac{\Gamma(B\to D^{(*)}\tau\nu)}{\Gamma(B\to D^{(*)}\ell\nu)}$ ($\ell=e,\mu$) show a $3.9\sigma$ deviation from the Standard Model prediction. In the absence of light right-handed neutrinos, a new physics contribution to $b\to c\tau\nu$ decays necessarily modifies also $b\bar b\to\tau^+\tau^-$ and/or $c\bar c\to\tau^+\tau^-$ transitions. These contributions lead to violation of lepton flavor universality in, respectively, $\Upsilon$ and $\psi$ leptonic decays. We analyze the constraints resulting from measurements of the leptonic vector-meson decays on solutions to the $R(D^{(*)})$ puzzle. Available data from BaBar and Belle can already disfavor some of the new physics explanations of this anomaly. Further discrimination can be made by measuring $\Upsilon(1S,2S,3S)\to\tau\tau$ in the upcoming Belle II experiment.
[ { "created": "Thu, 23 Feb 2017 19:00:21 GMT", "version": "v1" }, { "created": "Thu, 8 Jun 2017 10:21:26 GMT", "version": "v2" } ]
2017-06-09
[ [ "Aloni", "Daniel", "" ], [ "Efrati", "Aielet", "" ], [ "Grossman", "Yuval", "" ], [ "Nir", "Yosef", "" ] ]
Experimental measurements of the ratios $R(D^{(*)})\equiv\frac{\Gamma(B\to D^{(*)}\tau\nu)}{\Gamma(B\to D^{(*)}\ell\nu)}$ ($\ell=e,\mu$) show a $3.9\sigma$ deviation from the Standard Model prediction. In the absence of light right-handed neutrinos, a new physics contribution to $b\to c\tau\nu$ decays necessarily modifies also $b\bar b\to\tau^+\tau^-$ and/or $c\bar c\to\tau^+\tau^-$ transitions. These contributions lead to violation of lepton flavor universality in, respectively, $\Upsilon$ and $\psi$ leptonic decays. We analyze the constraints resulting from measurements of the leptonic vector-meson decays on solutions to the $R(D^{(*)})$ puzzle. Available data from BaBar and Belle can already disfavor some of the new physics explanations of this anomaly. Further discrimination can be made by measuring $\Upsilon(1S,2S,3S)\to\tau\tau$ in the upcoming Belle II experiment.
1609.00148
Hjalte Frellesvig Dr.
Hjalte Frellesvig, Damiano Tommasini, Christopher Wever
On the Reduction and Evaluation of Generalized Polylogarithms
7 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is a contribution to the proceedings of the 2016 "Loops and legs" conference, based on the talk by HF. The talk was based on the paper "On the reduction of Generalized Polylogarithms to $\text{Li}_n$ and $\text{Li}_{2,2}$ and on the reduction thereof" by the three authors, published in March 2016 in JHEP.
[ { "created": "Thu, 1 Sep 2016 08:53:48 GMT", "version": "v1" } ]
2016-09-02
[ [ "Frellesvig", "Hjalte", "" ], [ "Tommasini", "Damiano", "" ], [ "Wever", "Christopher", "" ] ]
This is a contribution to the proceedings of the 2016 "Loops and legs" conference, based on the talk by HF. The talk was based on the paper "On the reduction of Generalized Polylogarithms to $\text{Li}_n$ and $\text{Li}_{2,2}$ and on the reduction thereof" by the three authors, published in March 2016 in JHEP.
0808.0758
Scott A. Yost
Nadia E. Adam, Valerie Halyo, Scott A. Yost, and Wenhan Zhu
Evaluation of the Theoretical Uncertainties in the W to Lepton and Neutrino Cross Sections at the LHC
33 pages, 109 eps figures, uses JHEP3.cls, rotating.sty Version 2 corrects an error in Table 1, adds some references, and updates an author address
JHEP 0809:133,2008
10.1088/1126-6708/2008/09/133
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the sources of systematic errors in the measurement of the W to lepton and neutrino cross-sections at the LHC. We consider the systematic errors in both the total cross-section and acceptance for anticipated experimental cuts. We include the best available analysis of QCD effects at NNLO in assessing the effect of higher order corrections and PDF and scale uncertainties on the theoretical acceptance. In addition, we evaluate the error due to missing NLO electroweak corrections and propose which MC generators and computational schemes should be implemented to best simulate the events.
[ { "created": "Wed, 6 Aug 2008 01:39:00 GMT", "version": "v1" }, { "created": "Wed, 27 Aug 2008 23:18:03 GMT", "version": "v2" } ]
2009-02-18
[ [ "Adam", "Nadia E.", "" ], [ "Halyo", "Valerie", "" ], [ "Yost", "Scott A.", "" ], [ "Zhu", "Wenhan", "" ] ]
We study the sources of systematic errors in the measurement of the W to lepton and neutrino cross-sections at the LHC. We consider the systematic errors in both the total cross-section and acceptance for anticipated experimental cuts. We include the best available analysis of QCD effects at NNLO in assessing the effect of higher order corrections and PDF and scale uncertainties on the theoretical acceptance. In addition, we evaluate the error due to missing NLO electroweak corrections and propose which MC generators and computational schemes should be implemented to best simulate the events.
hep-ph/0012367
Timo Paulus
H.G. Dosch, O. Nachtmann, T. Paulus, S. Weinstock
Inelastic diffractive scattering in nonperturbative QCD
32 pages, 11 figures, v3: revised chapter 5, added appendix B, to be published in Eur.Phys.J. C
Eur.Phys.J.C21:339-353,2001
10.1007/s100520100740
HD-THEP-00-65
hep-ph
null
We examine diffractive proton-proton scattering p p -> p X and photo- and electroproduction of \rho^0 mesons \gamma^(*) p -> \rho^0 X, where X denotes a proton or a final state, into which the proton can go by diffractive dissociation. Using a functional integral approach we derive the scattering amplitudes, which are governed by the expectation values of light-like Wegner-Wilson loops, which are then evaluated using the model of the stochastic vacuum. For the proton, we assume a quark-diquark structure. From the scattering amplitudes we calculate total and differential cross sections for high centre of mass energy and small momentum transfer and compare with experiments. Furthermore we calculate isovector form factors for the proton and the pion within the same model.
[ { "created": "Thu, 28 Dec 2000 23:58:20 GMT", "version": "v1" }, { "created": "Fri, 29 Dec 2000 00:27:20 GMT", "version": "v2" }, { "created": "Thu, 26 Jul 2001 17:39:32 GMT", "version": "v3" } ]
2008-11-26
[ [ "Dosch", "H. G.", "" ], [ "Nachtmann", "O.", "" ], [ "Paulus", "T.", "" ], [ "Weinstock", "S.", "" ] ]
We examine diffractive proton-proton scattering p p -> p X and photo- and electroproduction of \rho^0 mesons \gamma^(*) p -> \rho^0 X, where X denotes a proton or a final state, into which the proton can go by diffractive dissociation. Using a functional integral approach we derive the scattering amplitudes, which are governed by the expectation values of light-like Wegner-Wilson loops, which are then evaluated using the model of the stochastic vacuum. For the proton, we assume a quark-diquark structure. From the scattering amplitudes we calculate total and differential cross sections for high centre of mass energy and small momentum transfer and compare with experiments. Furthermore we calculate isovector form factors for the proton and the pion within the same model.
2403.13894
Sergio Barbosa Junior
Sergio Barbosa, Sylvain Fichet
Background-Induced Forces from Dark Relics
36 pages, 5 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Light particles quadratically coupled to nucleons induce macroscopic forces in matter. While a quantum effect always exists, an additional force occurs in the presence of a finite density of the light particles. We compute and classify such background-induced forces for particles of spin $0,\frac{1}{2},1$ in the framework of effective field theory. We show that, at short distance, the background-induced forces exhibit a universal behavior that depends solely on the moments of the phase space distribution function of the light particles. We compute the forces in the case of thermal-like densities of dark particles that may realistically occur in cosmology. All the background-induced forces remain, unlike the quantum ones, exponentially unsuppressed at large distance, implying that large scale fifth force experiments are highly sensitive to dark relics. Moreover at zero mass the forces from dark bosons are generically enhanced with respect to their quantum counterpart due to Bose-Einstein distribution. Overall, we find that the resulting fifth force bounds can compete with those from quantum forces. A thorough adaptation of the results from the E\"ot-Wash experiment may produce powerful additional bounds.
[ { "created": "Wed, 20 Mar 2024 18:05:57 GMT", "version": "v1" } ]
2024-03-22
[ [ "Barbosa", "Sergio", "" ], [ "Fichet", "Sylvain", "" ] ]
Light particles quadratically coupled to nucleons induce macroscopic forces in matter. While a quantum effect always exists, an additional force occurs in the presence of a finite density of the light particles. We compute and classify such background-induced forces for particles of spin $0,\frac{1}{2},1$ in the framework of effective field theory. We show that, at short distance, the background-induced forces exhibit a universal behavior that depends solely on the moments of the phase space distribution function of the light particles. We compute the forces in the case of thermal-like densities of dark particles that may realistically occur in cosmology. All the background-induced forces remain, unlike the quantum ones, exponentially unsuppressed at large distance, implying that large scale fifth force experiments are highly sensitive to dark relics. Moreover at zero mass the forces from dark bosons are generically enhanced with respect to their quantum counterpart due to Bose-Einstein distribution. Overall, we find that the resulting fifth force bounds can compete with those from quantum forces. A thorough adaptation of the results from the E\"ot-Wash experiment may produce powerful additional bounds.
hep-ph/9612447
Sourov Roy
Sourov Roy and Biswarup Mukhopadhyaya
Some Implications of a Supersymmetric Model with R-Parity Breaking Bilinear Interactions
26 Pages, 6 Postscript figures, Latex. An additional set of references has been included. Typographic corrections have been made. Figures remain all unchanged. An additional typographic correction has been made
Phys.Rev. D55 (1997) 7020-7029
10.1103/PhysRevD.55.7020
MRI-PHY/96-37
hep-ph
null
We investigate a supersymmetric scenario where R-parity is explicitly broken through a term bilinear in the lepton and Higgs superfields in the superpotential. We show that keeping such a term alone can lead to trilinear interactions, similar to those that are parametrized by $\lambda$-and ${\lambda}'$ in the literature, involving the physical fields. The upper limits of such interactions are predictable from the constraints on the parameter space imposed by the lepton masses and the neutrino mass limits. It is observed that thus the resulting trilinear interactions are restricted to values that are smaller than the existing bounds on most of the $\lambda$-and ${\lambda}'$-parameters. Some phenomenological consequences of such a scenario are discussed.
[ { "created": "Sun, 22 Dec 1996 23:06:25 GMT", "version": "v1" }, { "created": "Mon, 10 Mar 1997 15:48:27 GMT", "version": "v2" }, { "created": "Wed, 19 Mar 1997 09:28:11 GMT", "version": "v3" } ]
2009-10-30
[ [ "Roy", "Sourov", "" ], [ "Mukhopadhyaya", "Biswarup", "" ] ]
We investigate a supersymmetric scenario where R-parity is explicitly broken through a term bilinear in the lepton and Higgs superfields in the superpotential. We show that keeping such a term alone can lead to trilinear interactions, similar to those that are parametrized by $\lambda$-and ${\lambda}'$ in the literature, involving the physical fields. The upper limits of such interactions are predictable from the constraints on the parameter space imposed by the lepton masses and the neutrino mass limits. It is observed that thus the resulting trilinear interactions are restricted to values that are smaller than the existing bounds on most of the $\lambda$-and ${\lambda}'$-parameters. Some phenomenological consequences of such a scenario are discussed.
hep-ph/0212300
Alessandro Bacchetta
Alessandro Bacchetta and Marco Radici
Partial-wave analysis of two-hadron fragmentation functions
23 pages, 3 figures
Phys.Rev. D67 (2003) 094002
10.1103/PhysRevD.67.094002
null
hep-ph
null
We reconsider the option of extracting the transversity distribution by using interference fragmentation functions into two leading hadrons inside the same current jet. To this end, we perform a new study of two-hadron fragmentation functions. We derive new positivity bounds on them. We expand the hadron pair system in relative partial waves, so that we can naturally incorporate in a unified formalism specific cases already studied in the literature, such as the fragmentation functions arising from the interference between the s- and p-wave production of two mesons, as well as the production of a spin-one hadron. In particular, our analysis clearly distinguishes two different ways to access the transversity distribution in two-hadron semi-inclusive leptoproduction.
[ { "created": "Thu, 19 Dec 2002 18:19:30 GMT", "version": "v1" } ]
2009-11-07
[ [ "Bacchetta", "Alessandro", "" ], [ "Radici", "Marco", "" ] ]
We reconsider the option of extracting the transversity distribution by using interference fragmentation functions into two leading hadrons inside the same current jet. To this end, we perform a new study of two-hadron fragmentation functions. We derive new positivity bounds on them. We expand the hadron pair system in relative partial waves, so that we can naturally incorporate in a unified formalism specific cases already studied in the literature, such as the fragmentation functions arising from the interference between the s- and p-wave production of two mesons, as well as the production of a spin-one hadron. In particular, our analysis clearly distinguishes two different ways to access the transversity distribution in two-hadron semi-inclusive leptoproduction.
1811.10549
Thomas Edwards
Thomas D. P. Edwards, Bradley J. Kavanagh, Christoph Weniger, Sebastian Baum, Andrzej K. Drukier, Katherine Freese, Maciej G\'orski, Patrick Stengel
Digging for Dark Matter: Spectral Analysis and Discovery Potential of Paleo-Detectors
14 pages, 5 figures, code available at https://github.com/tedwards2412/paleo_detectors/ . v2: Added additional analysis theory details, matches version published in PRD
Phys. Rev. D 99, 043541 (2019)
10.1103/PhysRevD.99.043541
NORDITA-2018-119; LCTP-18-26
hep-ph astro-ph.CO astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Paleo-detectors are a recently proposed method for the direct detection of Dark Matter (DM). In such detectors, one would search for the persistent damage features left by DM--nucleus interactions in ancient minerals. Initial sensitivity projections have shown that paleo-detectors could probe much of the remaining Weakly Interacting Massive Particle (WIMP) parameter space. In this paper, we improve upon the cut-and-count approach previously used to estimate the sensitivity by performing a full spectral analysis of the background- and DM-induced signal spectra. We consider two scenarios for the systematic errors on the background spectra: i) systematic errors on the normalization only, and ii) systematic errors on the shape of the backgrounds. We find that the projected sensitivity is rather robust to imperfect knowledge of the backgrounds. Finally, we study how well the parameters of the true WIMP model could be reconstructed in the hypothetical case of a WIMP discovery.
[ { "created": "Mon, 26 Nov 2018 17:52:46 GMT", "version": "v1" }, { "created": "Tue, 26 Mar 2019 16:38:13 GMT", "version": "v2" } ]
2019-03-27
[ [ "Edwards", "Thomas D. P.", "" ], [ "Kavanagh", "Bradley J.", "" ], [ "Weniger", "Christoph", "" ], [ "Baum", "Sebastian", "" ], [ "Drukier", "Andrzej K.", "" ], [ "Freese", "Katherine", "" ], [ "Górski", "Maciej", "" ], [ "Stengel", "Patrick", "" ] ]
Paleo-detectors are a recently proposed method for the direct detection of Dark Matter (DM). In such detectors, one would search for the persistent damage features left by DM--nucleus interactions in ancient minerals. Initial sensitivity projections have shown that paleo-detectors could probe much of the remaining Weakly Interacting Massive Particle (WIMP) parameter space. In this paper, we improve upon the cut-and-count approach previously used to estimate the sensitivity by performing a full spectral analysis of the background- and DM-induced signal spectra. We consider two scenarios for the systematic errors on the background spectra: i) systematic errors on the normalization only, and ii) systematic errors on the shape of the backgrounds. We find that the projected sensitivity is rather robust to imperfect knowledge of the backgrounds. Finally, we study how well the parameters of the true WIMP model could be reconstructed in the hypothetical case of a WIMP discovery.
1101.6023
Baradhwaj Coleppa
R. Sekhar Chivukula, Baradhwaj Coleppa, Heather E. Logan, Adam Martin, and Elizabeth H. Simmons
Top-Higgs and Top-pion phenomenology in the Top Triangle Moose model
29 pages, 17 figures
Phys.Rev.D83:055013,2011
10.1103/PhysRevD.83.055013
FERMILAB-PUB-11-017-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the deconstructed version of a topcolor-assisted technicolor model wherein the mechanism of top quark mass generation is separated from the rest of electroweak symmetry breaking. The minimal deconstructed version of this scenario is a "triangle moose" model, where the top quark gets its mass from coupling to a top-Higgs field, while the gauge boson masses are generated from a Higgsless sector. The spectrum of the model includes scalar (top-Higgs) and pseudoscalar (top-pion) states. In this paper, we study the properties of these particles, discuss their production mechanisms and decay modes, and suggest how best to search for them at the LHC.
[ { "created": "Mon, 31 Jan 2011 17:05:11 GMT", "version": "v1" } ]
2015-03-18
[ [ "Chivukula", "R. Sekhar", "" ], [ "Coleppa", "Baradhwaj", "" ], [ "Logan", "Heather E.", "" ], [ "Martin", "Adam", "" ], [ "Simmons", "Elizabeth H.", "" ] ]
We discuss the deconstructed version of a topcolor-assisted technicolor model wherein the mechanism of top quark mass generation is separated from the rest of electroweak symmetry breaking. The minimal deconstructed version of this scenario is a "triangle moose" model, where the top quark gets its mass from coupling to a top-Higgs field, while the gauge boson masses are generated from a Higgsless sector. The spectrum of the model includes scalar (top-Higgs) and pseudoscalar (top-pion) states. In this paper, we study the properties of these particles, discuss their production mechanisms and decay modes, and suggest how best to search for them at the LHC.
1703.04073
Atsunari Konishi
Atsunari Konishi, Osamu Morimatsu, Shigehiro Yasui
A Study of Degenerate Two-Body and Three-Body Coupled-Channel Systems -Renormalized Effective AGS Equations and Near-Threshold Resonances-
26 pages, 12 figures
Phys. Rev. C 97, 064001 (2018)
10.1103/PhysRevC.97.064001
KEK-TH 1956
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the existence of candidates for exotic hadrons whose masses are close to both of two-body and three-body hadronic thresholds lying close to each other, we study degenerate two-body and three-body coupled-channel systems. We first formulate the scattering problem of non-degenerate two-body and three-body coupled-channels as an effective three-body problem, i.e.\ effective Alt-Grassberger-Sandhas (AGS) equations. We next investigate the behavior of $S$-matrix poles near the threshold when two-body and three-body thresholds are degenerate. We solve the eigenvalue equations of the kernel of AGS equations instead of AGS equations themselves to obtain the $S$-matrix pole energy. We then face a problem of unphysical singularity: though the physical transition amplitudes have physical singularities only, the kernel of AGS equations have unphysical singularities. We show, however, that these unphysical singularities can be removed by appropriate reorganization of the scattering equations and mass renormalization. The behavior of $S$-matrix poles near the degenerate threshold is found to be universal in the sense that the complex pole energy, $E$, is determined by a real parameter, $c$, as $c - E \log{\left( - E \right)} = 0$, or equivalently, ${\rm Im} E = - \pi {\rm Re} E / \log{\mid {\rm Re} E \mid}$. This behavior is different from that of either two-body or three-body system and is characteristic in the degenerate two-body and three-body coupled-channel system. We expect that this new class of universal behavior might play a key role in understanding exotic hadrons.
[ { "created": "Sun, 12 Mar 2017 05:30:04 GMT", "version": "v1" }, { "created": "Sun, 10 Sep 2017 06:03:08 GMT", "version": "v2" } ]
2018-06-27
[ [ "Konishi", "Atsunari", "" ], [ "Morimatsu", "Osamu", "" ], [ "Yasui", "Shigehiro", "" ] ]
Motivated by the existence of candidates for exotic hadrons whose masses are close to both of two-body and three-body hadronic thresholds lying close to each other, we study degenerate two-body and three-body coupled-channel systems. We first formulate the scattering problem of non-degenerate two-body and three-body coupled-channels as an effective three-body problem, i.e.\ effective Alt-Grassberger-Sandhas (AGS) equations. We next investigate the behavior of $S$-matrix poles near the threshold when two-body and three-body thresholds are degenerate. We solve the eigenvalue equations of the kernel of AGS equations instead of AGS equations themselves to obtain the $S$-matrix pole energy. We then face a problem of unphysical singularity: though the physical transition amplitudes have physical singularities only, the kernel of AGS equations have unphysical singularities. We show, however, that these unphysical singularities can be removed by appropriate reorganization of the scattering equations and mass renormalization. The behavior of $S$-matrix poles near the degenerate threshold is found to be universal in the sense that the complex pole energy, $E$, is determined by a real parameter, $c$, as $c - E \log{\left( - E \right)} = 0$, or equivalently, ${\rm Im} E = - \pi {\rm Re} E / \log{\mid {\rm Re} E \mid}$. This behavior is different from that of either two-body or three-body system and is characteristic in the degenerate two-body and three-body coupled-channel system. We expect that this new class of universal behavior might play a key role in understanding exotic hadrons.
1812.03722
Jason Aebischer
Jason Aebischer
$\varepsilon'/\varepsilon$ in and beyond the Standard Model
10 pages, Proceedings of the 10th International Workshop on the CKM Unitarity Triangle (CKM 2018), Heidelberg, Germany, 17-21 September 2018
null
null
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Estimates of the CP violating observable $\varepsilon'/\varepsilon$ have gained some attention in the past few years. Depending on the long-distance treatment used, they exhibit up to $2.9\sigma$ deviation from the experimentally measured value. Such a deviation motivates the investigation of New Physics (NP) effects in the process $K\to\pi\pi$. In my talk I will review the Standard Model (SM) prediction for $\varepsilon'/\varepsilon$, with a special focus on the Dual QCD approach. On the NP side, I will discuss a recent computation of the hadronic matrix elements of NP operators. Furthermore a master formula for BSM effects in $\varepsilon'/\varepsilon$ is presented. Finally, a treatment of $\varepsilon'/\varepsilon$ using the SM effective theory (SMEFT) will be discussed together with possible correlations to other observables.
[ { "created": "Mon, 10 Dec 2018 10:30:39 GMT", "version": "v1" } ]
2018-12-11
[ [ "Aebischer", "Jason", "" ] ]
Estimates of the CP violating observable $\varepsilon'/\varepsilon$ have gained some attention in the past few years. Depending on the long-distance treatment used, they exhibit up to $2.9\sigma$ deviation from the experimentally measured value. Such a deviation motivates the investigation of New Physics (NP) effects in the process $K\to\pi\pi$. In my talk I will review the Standard Model (SM) prediction for $\varepsilon'/\varepsilon$, with a special focus on the Dual QCD approach. On the NP side, I will discuss a recent computation of the hadronic matrix elements of NP operators. Furthermore a master formula for BSM effects in $\varepsilon'/\varepsilon$ is presented. Finally, a treatment of $\varepsilon'/\varepsilon$ using the SM effective theory (SMEFT) will be discussed together with possible correlations to other observables.
0707.4168
Chun-Sheng An
Chun-Sheng An
The $qqqq\bar{q}$ components and the magnetic moments of the charmed and the bottomed baryons
Some references added, and typos corrected
Nucl.Phys.A797:131-144,2007; Erratum-ibid.A801:82,2008
10.1016/j.nuclphysa.2007.10.002 10.1016/j.nuclphysa.2007.12.002
null
hep-ph
null
We give the explicit wave functions of the $qqqq\bar{q}$ components of the C=+1, J=1/2 charmed baryons, $\Sigma_{c}$, $\Lambda_{c}$ and $\Xi_{c}^{a}$, and calculate the magnetic moments by adding the 5q components contributions, and we also compute the magnetic moments of the $\Sigma_{b}$ and $\Sigma_{b}^{*}$ baryons. The influence of the additional light and strange $q\bar{q}$ pairs is investigated. It's obvious that the constituent quark masses of the charm and beauty quarks are much heavier than that of the light and strange quarks, consequently, the hidden flavor contributions to the baryons magnetic moments may be significant. What is interesting is that the inclusion of the $qqqq\bar{q}$ components contributions leads to different $\Lambda^{+}_{c}$, $\Xi^{a+}_{c}$ and $\Xi^{a0}_{c}$ magnetic moments, all of which are predicted to be the same value $0.38\mu_{N}$ on the basis of the classical qqq quark model. And it's shown that the differences of these magnetic moments are independent of the constituent mass of the charm quark.
[ { "created": "Sat, 28 Jul 2007 14:41:03 GMT", "version": "v1" }, { "created": "Thu, 22 Nov 2007 15:35:43 GMT", "version": "v2" }, { "created": "Tue, 27 Nov 2007 04:49:31 GMT", "version": "v3" } ]
2008-11-26
[ [ "An", "Chun-Sheng", "" ] ]
We give the explicit wave functions of the $qqqq\bar{q}$ components of the C=+1, J=1/2 charmed baryons, $\Sigma_{c}$, $\Lambda_{c}$ and $\Xi_{c}^{a}$, and calculate the magnetic moments by adding the 5q components contributions, and we also compute the magnetic moments of the $\Sigma_{b}$ and $\Sigma_{b}^{*}$ baryons. The influence of the additional light and strange $q\bar{q}$ pairs is investigated. It's obvious that the constituent quark masses of the charm and beauty quarks are much heavier than that of the light and strange quarks, consequently, the hidden flavor contributions to the baryons magnetic moments may be significant. What is interesting is that the inclusion of the $qqqq\bar{q}$ components contributions leads to different $\Lambda^{+}_{c}$, $\Xi^{a+}_{c}$ and $\Xi^{a0}_{c}$ magnetic moments, all of which are predicted to be the same value $0.38\mu_{N}$ on the basis of the classical qqq quark model. And it's shown that the differences of these magnetic moments are independent of the constituent mass of the charm quark.
1409.3454
Hiranmaya Mishra
Bhaswar Chatterjee, Hiranmaya Mishra and Amruta Mishra
CP violation and chiral symmetry breaking in hot and dense quark matter in presence of magnetic field
14 pages with 13 Figures. arXiv admin note: text overlap with arXiv:1101.0498
null
10.1103/PhysRevD.91.034031
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate chiral symmetry breaking and strong CP violation effects on the phase diagram of strongly interacting matter in presence of a constant magnetic field. The effect of magnetic field and strong CP violating term on the phase structure at finite temperature and density is studied within a three flavor Nambu-Jona-Lasinio (NJL) model including the Kobayashi-Maskawa-t'Hooft (KMT) determinant term. This is investigated using an explicit variational ansatz for ground state with quark anti-quark pairs leading to condensates both in scalar and pseudoscalar channels. Magnetic field enhances the condensate in both the channels. Inverse magnetic catalysis for CP transition at finite chemical potential is seen for zero temperature and for small magnetic fields.
[ { "created": "Thu, 11 Sep 2014 14:25:13 GMT", "version": "v1" } ]
2015-06-22
[ [ "Chatterjee", "Bhaswar", "" ], [ "Mishra", "Hiranmaya", "" ], [ "Mishra", "Amruta", "" ] ]
We investigate chiral symmetry breaking and strong CP violation effects on the phase diagram of strongly interacting matter in presence of a constant magnetic field. The effect of magnetic field and strong CP violating term on the phase structure at finite temperature and density is studied within a three flavor Nambu-Jona-Lasinio (NJL) model including the Kobayashi-Maskawa-t'Hooft (KMT) determinant term. This is investigated using an explicit variational ansatz for ground state with quark anti-quark pairs leading to condensates both in scalar and pseudoscalar channels. Magnetic field enhances the condensate in both the channels. Inverse magnetic catalysis for CP transition at finite chemical potential is seen for zero temperature and for small magnetic fields.
2205.12963
Martin Hoferichter
G. Colangelo, A. X. El-Khadra, M. Hoferichter, A. Keshavarzi, C. Lehner, P. Stoffer, T. Teubner
Data-driven evaluations of Euclidean windows to scrutinize hadronic vacuum polarization
9 pages, 4 figures; journal version
Phys. Lett. B 833 (2022) 137313
10.1016/j.physletb.2022.137313
FERMILAB-PUB-22-443-V, LTH 1304, PSI-PR-22-13, ZU-TH 20/22
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we discuss how windows in Euclidean time can be used to isolate the origin of potential conflicts between evaluations of the hadronic-vacuum-polarization (HVP) contribution to the anomalous magnetic moment of the muon in lattice QCD and from $e^+e^-\to\text{hadrons}$ cross-section data. We provide phenomenological comparison numbers evaluated from $e^+e^-\to\text{hadrons}$ data for the window quantities most commonly studied in lattice QCD, complete with the correlations among them. We discuss and evaluate modifications of window parameters that could be useful in dissecting the energy dependence of tensions in the HVP integral and emphasize that further optimizations require a precise knowledge of the full covariance matrix in lattice-QCD calculations as well.
[ { "created": "Wed, 25 May 2022 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 25 Jul 2022 17:36:08 GMT", "version": "v2" } ]
2022-07-26
[ [ "Colangelo", "G.", "" ], [ "El-Khadra", "A. X.", "" ], [ "Hoferichter", "M.", "" ], [ "Keshavarzi", "A.", "" ], [ "Lehner", "C.", "" ], [ "Stoffer", "P.", "" ], [ "Teubner", "T.", "" ] ]
In this paper, we discuss how windows in Euclidean time can be used to isolate the origin of potential conflicts between evaluations of the hadronic-vacuum-polarization (HVP) contribution to the anomalous magnetic moment of the muon in lattice QCD and from $e^+e^-\to\text{hadrons}$ cross-section data. We provide phenomenological comparison numbers evaluated from $e^+e^-\to\text{hadrons}$ data for the window quantities most commonly studied in lattice QCD, complete with the correlations among them. We discuss and evaluate modifications of window parameters that could be useful in dissecting the energy dependence of tensions in the HVP integral and emphasize that further optimizations require a precise knowledge of the full covariance matrix in lattice-QCD calculations as well.
hep-ph/0210172
Alex Gomes Dias
Alex G. Dias, V. Pleitez, M. D. Tonasse
Naturally light invisible axion and local Z_{13} times Z_3 symmetries
PQ charges and typos corrected
Phys.Rev. D69 (2004) 015007
10.1103/PhysRevD.69.015007
null
hep-ph astro-ph hep-th
null
We show that by imposing local $Z_{13}\otimes Z_3$ symmetries in an $SU(2)\otimes U(1)$ electroweak model we can implement an invisible axion in such a way that (i) the Peccei-Quinn symmetry is an automatic symmetry of the classical Lagrangian; and (ii) the axion is protected from semi classical gravitational effects. In order to be able to implement such a large discrete symmetry, and at the same time allow a general mixing in each charge sector, we introduce right-handed neutrinos and enlarge the scalar sector of the model. The domain wall problem is briefly considered.
[ { "created": "Thu, 10 Oct 2002 22:53:58 GMT", "version": "v1" }, { "created": "Mon, 28 Oct 2002 16:30:35 GMT", "version": "v2" }, { "created": "Wed, 12 Feb 2003 16:14:06 GMT", "version": "v3" }, { "created": "Thu, 15 Apr 2004 19:24:53 GMT", "version": "v4" } ]
2009-11-07
[ [ "Dias", "Alex G.", "" ], [ "Pleitez", "V.", "" ], [ "Tonasse", "M. D.", "" ] ]
We show that by imposing local $Z_{13}\otimes Z_3$ symmetries in an $SU(2)\otimes U(1)$ electroweak model we can implement an invisible axion in such a way that (i) the Peccei-Quinn symmetry is an automatic symmetry of the classical Lagrangian; and (ii) the axion is protected from semi classical gravitational effects. In order to be able to implement such a large discrete symmetry, and at the same time allow a general mixing in each charge sector, we introduce right-handed neutrinos and enlarge the scalar sector of the model. The domain wall problem is briefly considered.
hep-ph/0210350
Genevieve Belanger
G. Belanger
micrOMEGAs and the relic density in the MSSM
10 pages, 3 figures, Talk at CPP2001, Tokyo, Japan
null
null
LAPTH-CONF-920
hep-ph
null
micrOMEGAs is a program that calculates the relic density of the lightest supersymmetric particle in the MSSM. All tree-level processes for the annihilation of the LSP are included as well as all possible coannihilation processes. The cross-sections extracted from CompHEP are calculated exactly. Relativistic formulae for the thermal average are used and care is taken to handle poles and thresholds by adopting specific integration routines. The Higgs masses are calculated with FeynHiggsFast and the QCD corrected Higgs widths with HDECAY.
[ { "created": "Fri, 25 Oct 2002 12:30:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Belanger", "G.", "" ] ]
micrOMEGAs is a program that calculates the relic density of the lightest supersymmetric particle in the MSSM. All tree-level processes for the annihilation of the LSP are included as well as all possible coannihilation processes. The cross-sections extracted from CompHEP are calculated exactly. Relativistic formulae for the thermal average are used and care is taken to handle poles and thresholds by adopting specific integration routines. The Higgs masses are calculated with FeynHiggsFast and the QCD corrected Higgs widths with HDECAY.
hep-ph/0610244
Lianshou Liu
Xu Mingmei and Liu Lianshou
A Monte Carlo Study on the Identification of Quark-gluon Fusion Product in QCD-instanton Induced Processes in Deep-inelastic Scattering
7 pages, 12 figures
null
null
null
hep-ph
null
Different methods to reconstruct the quark-gluon fusion product and current jet are tried in deep-inelastic e-p scattering events with instanton as background generated by QCDINS Monte Carlo code. A comparison of these methods are performed and a good method is found which can reconstruct well the energies of current jet and instanton product as well as the mass of the latter. The isotropy property of the instanton product and jet are calculated and compared. A parameter characterizing the degree of ``hardness'' of the instanton product is presented.
[ { "created": "Wed, 18 Oct 2006 21:25:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mingmei", "Xu", "" ], [ "Lianshou", "Liu", "" ] ]
Different methods to reconstruct the quark-gluon fusion product and current jet are tried in deep-inelastic e-p scattering events with instanton as background generated by QCDINS Monte Carlo code. A comparison of these methods are performed and a good method is found which can reconstruct well the energies of current jet and instanton product as well as the mass of the latter. The isotropy property of the instanton product and jet are calculated and compared. A parameter characterizing the degree of ``hardness'' of the instanton product is presented.
1407.3649
Piotr Lebiedowicz
Piotr Lebiedowicz, Otto Nachtmann, Antoni Szczurek
Applications of the tensor pomeron model to exclusive central diffractive meson production
7 pages, 5 figures, presented by P. Lebiedowicz at DIS2014, 28 April - 2 May 2014, Warsaw, Poland, PoS(DIS2014)097
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss exclusive central diffractive production of scalar ($f_{0}(980)$, $f_{0}(1370)$, $f_{0}(1500)$), pseudoscalar ($\eta$, $\eta'(958)$), and vector ($\rho^{0}$) mesons in proton-proton collisions. We show that high-energy central production of mesons could provide crucial information on the spin structure of the soft pomeron. The amplitudes are formulated in terms of effective vertices respecting standard rules of Quantum Field Theory and propagators for the exchanged pomeron and reggeons. For the scalar and pseudoscalar meson production, in most cases, two lowest orbital angular momentum - spin couplings are necessary to describe WA102 experimental differential distributions. Different pomeron-pomeron-meson tensorial (vectorial) coupling structures are possible in general. For the $\rho^{0}$ production the photon-tensor pomeron/reggeon exchanges are considered and the coupling parameters are fixed from the H1 and ZEUS experimental data of the $\gamma p \to \rho^{0} p$ reaction. We present first predictions of this mechanism for the $pp \to pp (\rho^{0} \to \pi^{+} \pi^{-})$ reaction being studied at COMPASS, RHIC, Tevatron, and LHC. We analyse influence of the experimental cuts on integrated cross section and various differential distributions for produced mesons.
[ { "created": "Mon, 14 Jul 2014 13:42:52 GMT", "version": "v1" } ]
2014-07-15
[ [ "Lebiedowicz", "Piotr", "" ], [ "Nachtmann", "Otto", "" ], [ "Szczurek", "Antoni", "" ] ]
We discuss exclusive central diffractive production of scalar ($f_{0}(980)$, $f_{0}(1370)$, $f_{0}(1500)$), pseudoscalar ($\eta$, $\eta'(958)$), and vector ($\rho^{0}$) mesons in proton-proton collisions. We show that high-energy central production of mesons could provide crucial information on the spin structure of the soft pomeron. The amplitudes are formulated in terms of effective vertices respecting standard rules of Quantum Field Theory and propagators for the exchanged pomeron and reggeons. For the scalar and pseudoscalar meson production, in most cases, two lowest orbital angular momentum - spin couplings are necessary to describe WA102 experimental differential distributions. Different pomeron-pomeron-meson tensorial (vectorial) coupling structures are possible in general. For the $\rho^{0}$ production the photon-tensor pomeron/reggeon exchanges are considered and the coupling parameters are fixed from the H1 and ZEUS experimental data of the $\gamma p \to \rho^{0} p$ reaction. We present first predictions of this mechanism for the $pp \to pp (\rho^{0} \to \pi^{+} \pi^{-})$ reaction being studied at COMPASS, RHIC, Tevatron, and LHC. We analyse influence of the experimental cuts on integrated cross section and various differential distributions for produced mesons.
hep-ph/9512210
Wolf-Dieter Nowak
Wolf-Dieter Nowak (DESY - Zeuthen)
Measurement of Singly Polarized p + N(pol) Collisions at HERA
Contribution to the Proceedings of the 'Workshop on the Prospects of Spin Physics at HERA', held at DESY-Zeuthen, August 28-31, 1995 Proceedings volume to be published as DESY 95-200, report on p.145 Figures are uuencoded in 'prep1195.uu': 6 pages as six '.eps' files
null
null
DESY--Zeuthen 95--06, Internal Report, December 1995
hep-ph
null
A summary is given on the physics potential of measuring singly polarized proton--nucleon collisions using a polarized internal target in the 820 GeV HERA proton beam. This summary is based upon talks given at the 2nd Meeting on 'Possible Measurements of Singly Polarized p + p(pol) and p + n(pol) Collisions at HERA' which was held at DESY Zeuthen from August 31 to September 2, 1995 as a follow-up to the 'Workshop on the Prospects of Spin Physics at HERA.
[ { "created": "Fri, 1 Dec 1995 20:14:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nowak", "Wolf-Dieter", "", "DESY - Zeuthen" ] ]
A summary is given on the physics potential of measuring singly polarized proton--nucleon collisions using a polarized internal target in the 820 GeV HERA proton beam. This summary is based upon talks given at the 2nd Meeting on 'Possible Measurements of Singly Polarized p + p(pol) and p + n(pol) Collisions at HERA' which was held at DESY Zeuthen from August 31 to September 2, 1995 as a follow-up to the 'Workshop on the Prospects of Spin Physics at HERA.
1809.10102
Robert Vertesi
Zolt\'an Varga, R\'obert V\'ertesi and Gergely G\'abor Barnaf\"oldi
Multiplicity Dependence of the Jet Structures in pp Collisions at LHC Energies
Presented at Hot Quarks 2018 -- Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions, Texel, The Netherlands, September 7-14 2018. Submitted to MDPI Proceedings
MDPI Proc. 10 (2019) no.1, 3
10.3390/proceedings2019010003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the event multiplicity dependence of the jet structure in pp collisions. We present evidence for jet shape modification due to multi-parton interactions using PYTHIA and HIJING++ Monte Carlo (MC) event generators as an input to our analysis. We introduce a characteristic jet size measure which is independent of the choice of the simulation parameters, parton distribution functions, jet reconstruction algorithms and even of the presence or absence of multi-parton interactions. We also investigate heavy-flavor jets and show the sensitivity of the multiplicity-differential jet structure to flavor-dependent fragmentation.
[ { "created": "Wed, 26 Sep 2018 16:24:32 GMT", "version": "v1" }, { "created": "Tue, 9 Oct 2018 16:27:50 GMT", "version": "v2" } ]
2019-04-30
[ [ "Varga", "Zoltán", "" ], [ "Vértesi", "Róbert", "" ], [ "Barnaföldi", "Gergely Gábor", "" ] ]
We study the event multiplicity dependence of the jet structure in pp collisions. We present evidence for jet shape modification due to multi-parton interactions using PYTHIA and HIJING++ Monte Carlo (MC) event generators as an input to our analysis. We introduce a characteristic jet size measure which is independent of the choice of the simulation parameters, parton distribution functions, jet reconstruction algorithms and even of the presence or absence of multi-parton interactions. We also investigate heavy-flavor jets and show the sensitivity of the multiplicity-differential jet structure to flavor-dependent fragmentation.
hep-ph/0411001
Michael McNeil Forbes
Michael McNeil Forbes
Kaon Condensation in a Nambu--Jona-Lasinio (NJL) Model at High Density
21 pages, ReVTeX4. Clarified discussion and minor changes
Phys.Rev. D72 (2005) 094032
10.1103/PhysRevD.72.094032
MIT-CTP-3554
hep-ph nucl-th
null
We demonstrate a fully self-consistent microscopic realization of a kaon-condensed colour-flavour locked state (CFLK0) within the context of a mean-field NJL model at high density. The properties of this state are shown to be consistent with the QCD low-energy effective theory once the proper gauge neutrality conditions are satisfied, and a simple matching procedure is used to compute the pion decay constant, which agrees with the perturbative QCD result. The NJL model is used to compare the energies of the CFLK0 state to the parity even CFL state, and to determine locations of the metal/insulator transition to a phase with gapless fermionic excitations in the presence of a non-zero hypercharge chemical potential and a non-zero strange quark mass. The transition points are compared with results derived previously via effective theories and with partially self-consistent NJL calculations. We find that the qualitative physics does not change, but that the transitions are slightly lower.
[ { "created": "Mon, 1 Nov 2004 19:56:27 GMT", "version": "v1" }, { "created": "Mon, 23 Jan 2006 17:18:18 GMT", "version": "v2" } ]
2011-10-25
[ [ "Forbes", "Michael McNeil", "" ] ]
We demonstrate a fully self-consistent microscopic realization of a kaon-condensed colour-flavour locked state (CFLK0) within the context of a mean-field NJL model at high density. The properties of this state are shown to be consistent with the QCD low-energy effective theory once the proper gauge neutrality conditions are satisfied, and a simple matching procedure is used to compute the pion decay constant, which agrees with the perturbative QCD result. The NJL model is used to compare the energies of the CFLK0 state to the parity even CFL state, and to determine locations of the metal/insulator transition to a phase with gapless fermionic excitations in the presence of a non-zero hypercharge chemical potential and a non-zero strange quark mass. The transition points are compared with results derived previously via effective theories and with partially self-consistent NJL calculations. We find that the qualitative physics does not change, but that the transitions are slightly lower.
hep-ph/9405227
Jaewan Kim
Jaewan Kim and Pierre Sikivie
Stretching Wiggly Strings
Written with ReVTeX 3.0 package. Two figures are not included. Complete paper with postscript figures can be retrieved through anonymous ftp @quark.phys.ufl.edu. Get /preprints/ifthep94_4.tar.gz, gunzip and tar it. UFIFT-HEP-94-4
Phys.Rev. D50 (1994) 7410-7420
10.1103/PhysRevD.50.7410
null
hep-ph astro-ph hep-th
null
How does the amplitude of a wiggle on a string change when the string is stretched? We answer this question for both longitudinal and transverse wiggles and for arbitrary equation of state, {\it i.e.}, for arbitrary relation between the tension $\tau$ and the energy per unit length $\epsilon$ of the string. This completes our derivation of the renormalization of string parameters which results from averaging out small scale wiggles on a string. The program is presented here in its entirety.
[ { "created": "Thu, 5 May 1994 05:50:13 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kim", "Jaewan", "" ], [ "Sikivie", "Pierre", "" ] ]
How does the amplitude of a wiggle on a string change when the string is stretched? We answer this question for both longitudinal and transverse wiggles and for arbitrary equation of state, {\it i.e.}, for arbitrary relation between the tension $\tau$ and the energy per unit length $\epsilon$ of the string. This completes our derivation of the renormalization of string parameters which results from averaging out small scale wiggles on a string. The program is presented here in its entirety.
1507.04256
Roman Nikolaevich Lee
Roman N. Lee and Kirill T. Mingulov
Introducing SummerTime: a package for high-precision computation of sums appearing in DRA method
20 pages
null
10.1016/j.cpc.2016.02.018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce the Mathematica package SummerTime for arbitrary-precision computation of sums appearing in the results of DRA method. So far these results include the following families of the integrals: 3-loop onshell massless vertices, 3-loop onshell mass operator type integrals, 4-loop QED-type tadpoles, 4-loop massless propagators. The package can be used for high-precision numerical computation of the expansion coefficients of the integrals from the above families around arbitrary space-time dimension. In addition, this package can also be used for calculation of multiple zeta values, harmonic polylogarithms and other transcendental numbers expressed in terms of nested sums with factorized summand.
[ { "created": "Wed, 15 Jul 2015 15:23:10 GMT", "version": "v1" } ]
2016-05-04
[ [ "Lee", "Roman N.", "" ], [ "Mingulov", "Kirill T.", "" ] ]
We introduce the Mathematica package SummerTime for arbitrary-precision computation of sums appearing in the results of DRA method. So far these results include the following families of the integrals: 3-loop onshell massless vertices, 3-loop onshell mass operator type integrals, 4-loop QED-type tadpoles, 4-loop massless propagators. The package can be used for high-precision numerical computation of the expansion coefficients of the integrals from the above families around arbitrary space-time dimension. In addition, this package can also be used for calculation of multiple zeta values, harmonic polylogarithms and other transcendental numbers expressed in terms of nested sums with factorized summand.
0809.3080
Kenji Fukushima
Kenji Fukushima
Critical surface in hot and dense QCD with the vector interaction
6 pages, 7 figures; one figure added for a quantitative comparison, emphasis slightly shifted in Summary
Phys.Rev.D78:114019,2008
10.1103/PhysRevD.78.114019
YITP-08-76
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the chiral phase transition of hot and dense quark matter. We illustrate that the first-order phase transition is generally favored at high baryon density and the repulsive vector-vector interaction weakens the first-order phase transition. We use the Nambu--Jona-Lasinio model with the Polyakov loop coupling for concreteness. We locate the QCD critical surface on the quark mass plane for various values of the vector coupling constant. We find that, with increasing quark chemical potential, the first-order region in the quark mass plane could shrink for sufficiently large vector coupling. This may be a possible explanation for the recent lattice QCD results by de Forcrand and Philipsen.
[ { "created": "Thu, 18 Sep 2008 07:09:49 GMT", "version": "v1" }, { "created": "Wed, 5 Nov 2008 17:08:33 GMT", "version": "v2" } ]
2010-04-21
[ [ "Fukushima", "Kenji", "" ] ]
We discuss the chiral phase transition of hot and dense quark matter. We illustrate that the first-order phase transition is generally favored at high baryon density and the repulsive vector-vector interaction weakens the first-order phase transition. We use the Nambu--Jona-Lasinio model with the Polyakov loop coupling for concreteness. We locate the QCD critical surface on the quark mass plane for various values of the vector coupling constant. We find that, with increasing quark chemical potential, the first-order region in the quark mass plane could shrink for sufficiently large vector coupling. This may be a possible explanation for the recent lattice QCD results by de Forcrand and Philipsen.
1811.05944
Manuel Szewc
Ezequiel Alvarez and Manuel Szewc
Non-resonant Leptoquark with multigeneration couplings to $\mu\mu jj$ and $\mu\nu jj$ at LHC
Matches accepted version in PRD. An appendix has been added to address low energy flavour constraints in non-resonant scenarios with large couplings of O(1). 28 pages, 11 figures
Phys. Rev. D 99, 095004 (2019)
10.1103/PhysRevD.99.095004
ICAS 036/18
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
CMS has recently reported a moderate excess in the $\mu\nu jj$ final state in a second generation Leptoquark search, but they have disregarded it because the excess is not present in the $\mu\mu jj$ final state and because they do not observe the expected resonant peak in the distributions. As a proof of concept we show that a simple Leptoquark model including second and third generation couplings with non-negligible single- and non-resonant production in addition to usual pair production could explain the data: excess ($\mu\nu jj$), lack of excess ($\mu\mu jj$) and missing peak in the distributions; while being in agreement with collider constraints. We take this result and analysis as a starting point of a reconsideration of the ATLAS and CMS second generation Leptoquark searches. We also discuss which would be the consequences and modifications that should be performed in the searches to test if this deviation would correspond to a New Physics signal. We observe that low-energy flavor constraints can be avoided by adding heavier particles to the model.
[ { "created": "Wed, 14 Nov 2018 18:24:33 GMT", "version": "v1" }, { "created": "Mon, 11 Mar 2019 14:49:20 GMT", "version": "v2" } ]
2019-05-15
[ [ "Alvarez", "Ezequiel", "" ], [ "Szewc", "Manuel", "" ] ]
CMS has recently reported a moderate excess in the $\mu\nu jj$ final state in a second generation Leptoquark search, but they have disregarded it because the excess is not present in the $\mu\mu jj$ final state and because they do not observe the expected resonant peak in the distributions. As a proof of concept we show that a simple Leptoquark model including second and third generation couplings with non-negligible single- and non-resonant production in addition to usual pair production could explain the data: excess ($\mu\nu jj$), lack of excess ($\mu\mu jj$) and missing peak in the distributions; while being in agreement with collider constraints. We take this result and analysis as a starting point of a reconsideration of the ATLAS and CMS second generation Leptoquark searches. We also discuss which would be the consequences and modifications that should be performed in the searches to test if this deviation would correspond to a New Physics signal. We observe that low-energy flavor constraints can be avoided by adding heavier particles to the model.
1812.00138
Piotr Lebiedowicz
Piotr Lebiedowicz, Otto Nachtmann, Antoni Szczurek
Tensor pomeron, vector odderon and diffractive production of meson and baryon pairs in proton-proton collisions
10 pages, 6 figures, invited talk by P. Lebiedowicz at ISMD2018, 3-7 September 2018, Singapore
null
10.1051/epjconf/201920606005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review some selected results of the tensor-pomeron and vector-odderon model of soft high-energy proton-proton scattering and central exclusive production of meson and baryon pairs in proton-proton collisions. We discuss the theoretical aspects of this approach and consider the phenomenological implications in a variety of processes at high energies, comparing to existing experimental data. We consider the diffractive dipion and dikaon production including the continuum and the dominant scalar and tensor resonance contributions as well as the photoproduction processes. The theoretical results are compared with existing CDF experimental data and predictions for planned or current LHC experiments, ALICE, ATLAS, CMS, LHCb are presented.
[ { "created": "Sat, 1 Dec 2018 04:07:55 GMT", "version": "v1" } ]
2019-05-22
[ [ "Lebiedowicz", "Piotr", "" ], [ "Nachtmann", "Otto", "" ], [ "Szczurek", "Antoni", "" ] ]
We review some selected results of the tensor-pomeron and vector-odderon model of soft high-energy proton-proton scattering and central exclusive production of meson and baryon pairs in proton-proton collisions. We discuss the theoretical aspects of this approach and consider the phenomenological implications in a variety of processes at high energies, comparing to existing experimental data. We consider the diffractive dipion and dikaon production including the continuum and the dominant scalar and tensor resonance contributions as well as the photoproduction processes. The theoretical results are compared with existing CDF experimental data and predictions for planned or current LHC experiments, ALICE, ATLAS, CMS, LHCb are presented.
hep-ph/9312318
Fredrick Olness
M. A. G. Aivazis, Fredrick I. Olness, Wu-Ki Tung
Leptoproduction of Heavy Quarks I-- General Formalism and Kinematics of Charged Current and Neutral Current Production Processes
LaTeX format, 28 pages, 7 figures. Revised to make auto-TeX-able
Phys.Rev.D50:3085-3101,1994
10.1103/PhysRevD.50.3085
null
hep-ph
null
Existing calculations of heavy quark production in charged-current and neutral current lepton-hadron scattering are formulated differently because of the artificial distinction of ``light'' and ``heavy'' quarks made in the traditional approach. A proper QCD formalism valid for a wide kinematic range from near threshold to energies much higher then the quark mass should treat these processes in a uniform way. We formulate a unified approach to both types of leptoproduction processes based on the conventional factorization theorem. In this paper, we present the general framework with complete kinematics appropriate for arbitrary masses, emphasizing the simplifications provided by the helicity formalism. We illustrate this approach with an explicit calculation of the leading order contribution to the quark structure functions with general masses. This provides the basis for a complete QCD analysis of charged current and neutral current leptoproduction of charm and bottom quarks to be presented in subsequent papers.
[ { "created": "Tue, 21 Dec 1993 04:42:47 GMT", "version": "v1" }, { "created": "Tue, 8 Jun 1999 17:51:26 GMT", "version": "v2" } ]
2010-11-01
[ [ "Aivazis", "M. A. G.", "" ], [ "Olness", "Fredrick I.", "" ], [ "Tung", "Wu-Ki", "" ] ]
Existing calculations of heavy quark production in charged-current and neutral current lepton-hadron scattering are formulated differently because of the artificial distinction of ``light'' and ``heavy'' quarks made in the traditional approach. A proper QCD formalism valid for a wide kinematic range from near threshold to energies much higher then the quark mass should treat these processes in a uniform way. We formulate a unified approach to both types of leptoproduction processes based on the conventional factorization theorem. In this paper, we present the general framework with complete kinematics appropriate for arbitrary masses, emphasizing the simplifications provided by the helicity formalism. We illustrate this approach with an explicit calculation of the leading order contribution to the quark structure functions with general masses. This provides the basis for a complete QCD analysis of charged current and neutral current leptoproduction of charm and bottom quarks to be presented in subsequent papers.
1610.07059
Tord Riemann
I. Dubovyk (Univ. Hamburg), A. Freitas (Univ. Pittsburgh), J. Gluza (Univ. Katowice), T. Riemann (K\"onigs Wusterhausen and Univ. Katowice), J. Usovitsch (Humboldt-Univ. zu Berlin)
30 years, some 700 integrals, and 1 dessert, or: Electroweak two-loop corrections to the Zbb vertex
Contribution to the proceedings of the conference "Loops and Legs in Quantum Field Theory - LL 2016", 24 - 29 April 2016, Leipzig, Germany. Minor corrections in the text, few equations added. Version 2 compared to v.1: typos in eq. 1.24 corrected
PoS LL2016 (2016) 075
null
HU-EP 16/36, KW 16-003
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
The one-loop corrections to the weak mixing angle $\sin^2\theta_{eff}^b$ derived from the $Z{\bar b}b$ vertex, are known since 1985. It took another 30 years to calculate the complete electroweak two-loop corrections to $\sin^2\theta_{eff}^b$. The main obstacle was the calculation of the O(700) bosonic two-loop vertex integrals with up to three mass scales, at $s=M_Z^2$. We did not perform the usual integral reduction and master evaluation, but chose a completely numerical approach, using two different calculational chains. One method relies on publicly available sector decomposition implementations. Further, we derived Mellin-Barnes (MB) representations, exploring the publicly available MB suite. We had to supplement the MB suite by two new packages: AMBRE~3, a Mathematica program, for the efficient treatment of non-planar integrals and MBnumerics for advanced numerics in the Minkowskian space-time. Our preliminary result for LL2016, the "dessert", for the electroweak bosonic two-loop contributions to $\sin^2\theta_{eff}^b$ is: $\Delta \sin^2\theta_{eff}^{b(\alpha^2,\rm bos)} = \sin^2\theta_W ~ \Delta\kappa_b^{(\alpha^2,bos)}$, with $\Delta\kappa_b^{(\alpha^2,bos)} = -1.0276 x 10^{-4}$. This contribution is about a quarter of the corresponding fermionic corrections and of about the same magnitude as several of the known higher-order QCD corrections. The $\sin^2\theta_{eff}^b$ is now predicited in the Standard Model with a relative error of $10^{-4}$ [1].
[ { "created": "Sat, 22 Oct 2016 14:52:53 GMT", "version": "v1" }, { "created": "Sun, 6 Nov 2016 15:15:25 GMT", "version": "v2" } ]
2016-11-08
[ [ "Dubovyk", "I.", "", "Univ. Hamburg" ], [ "Freitas", "A.", "", "Univ. Pittsburgh" ], [ "Gluza", "J.", "", "Univ. Katowice" ], [ "Riemann", "T.", "", "Königs Wusterhausen and Univ. Katowice" ], [ "Usovitsch", "J.", "", "Humboldt-Univ. zu Berlin" ] ]
The one-loop corrections to the weak mixing angle $\sin^2\theta_{eff}^b$ derived from the $Z{\bar b}b$ vertex, are known since 1985. It took another 30 years to calculate the complete electroweak two-loop corrections to $\sin^2\theta_{eff}^b$. The main obstacle was the calculation of the O(700) bosonic two-loop vertex integrals with up to three mass scales, at $s=M_Z^2$. We did not perform the usual integral reduction and master evaluation, but chose a completely numerical approach, using two different calculational chains. One method relies on publicly available sector decomposition implementations. Further, we derived Mellin-Barnes (MB) representations, exploring the publicly available MB suite. We had to supplement the MB suite by two new packages: AMBRE~3, a Mathematica program, for the efficient treatment of non-planar integrals and MBnumerics for advanced numerics in the Minkowskian space-time. Our preliminary result for LL2016, the "dessert", for the electroweak bosonic two-loop contributions to $\sin^2\theta_{eff}^b$ is: $\Delta \sin^2\theta_{eff}^{b(\alpha^2,\rm bos)} = \sin^2\theta_W ~ \Delta\kappa_b^{(\alpha^2,bos)}$, with $\Delta\kappa_b^{(\alpha^2,bos)} = -1.0276 x 10^{-4}$. This contribution is about a quarter of the corresponding fermionic corrections and of about the same magnitude as several of the known higher-order QCD corrections. The $\sin^2\theta_{eff}^b$ is now predicited in the Standard Model with a relative error of $10^{-4}$ [1].
1901.00203
Mario Reig
Mario Reig
On the high-scale instanton interference effect: axion models without domain wall problem
7 pages, 2 figures. v2: references added, minor correction, conclusions unchanged. v3: discussion extended, title changed according to published version
JHEP08(2019)167
10.1007/JHEP08(2019)167
IFIC/19-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that a new chiral, confining interaction can be used to break Peccei-Quinn symmetry dynamically and solve the domain wall problem, simultaneously. The resulting theory is an invisible QCD axion model without domain walls. No dangerous heavy relics appear.
[ { "created": "Tue, 1 Jan 2019 19:39:28 GMT", "version": "v1" }, { "created": "Wed, 9 Jan 2019 12:01:15 GMT", "version": "v2" }, { "created": "Sun, 1 Sep 2019 12:59:59 GMT", "version": "v3" } ]
2019-09-04
[ [ "Reig", "Mario", "" ] ]
We show that a new chiral, confining interaction can be used to break Peccei-Quinn symmetry dynamically and solve the domain wall problem, simultaneously. The resulting theory is an invisible QCD axion model without domain walls. No dangerous heavy relics appear.
2107.04206
Yuan Shi
Yuan Shi
Nonperturbative $\phi^4$ potentials: Phase transitions and light horizons
16 pages, 6 figures, 1 table
null
null
LLNL-JRNL-823715
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is commonly believed that a massive real scalar field $\phi$ only mediates short-range interactions on the scale of its Compton wavelength via the Yukawa potential. However, in the nonperturbative regime of nonlinear self coupling, $\phi$ can also mediate larger scale interactions. Moreover, the classical potential, namely, the static configuration of $\phi$ in the presence of an external source, is not always unique for given boundary conditions. In this paper, a complete set of finite-energy potentials (FEPs) induced by a Gaussian source is identified in one, two, and three spatial dimensions when the nonlinearity is of the Mexican-hat type, which is often prescribed to induce spontaneous symmetry breaking. In the size-strength parameter space of the source, phase boundaries are mapped out, across which the number of FEPs differ. Additionally, softer phase transitions are delineated according to whether the potential exhibits a light horizon at which $\phi$ vanishes. The light horizon is of physical significance when $\phi$ couples with other particles. For example, when $\phi$ is the Higgs field, all elementary particles become massless at the light horizon. It is remarkable that white dwarfs and neutron stars are potentially in a phase where light horizons exist, whose outer radii are a few times the star sizes. Moreover, suppose elementary fermions of mass greater than $\sim10^3$ GeV exist, then they may also be surrounded by light horizons with radii comparable to the Higgs Compton wavelength. Finally, nonperturbative states may also be realized in condensed matter systems, wherein phase transitions are controllable using localized sources.
[ { "created": "Fri, 9 Jul 2021 04:47:23 GMT", "version": "v1" } ]
2021-07-12
[ [ "Shi", "Yuan", "" ] ]
It is commonly believed that a massive real scalar field $\phi$ only mediates short-range interactions on the scale of its Compton wavelength via the Yukawa potential. However, in the nonperturbative regime of nonlinear self coupling, $\phi$ can also mediate larger scale interactions. Moreover, the classical potential, namely, the static configuration of $\phi$ in the presence of an external source, is not always unique for given boundary conditions. In this paper, a complete set of finite-energy potentials (FEPs) induced by a Gaussian source is identified in one, two, and three spatial dimensions when the nonlinearity is of the Mexican-hat type, which is often prescribed to induce spontaneous symmetry breaking. In the size-strength parameter space of the source, phase boundaries are mapped out, across which the number of FEPs differ. Additionally, softer phase transitions are delineated according to whether the potential exhibits a light horizon at which $\phi$ vanishes. The light horizon is of physical significance when $\phi$ couples with other particles. For example, when $\phi$ is the Higgs field, all elementary particles become massless at the light horizon. It is remarkable that white dwarfs and neutron stars are potentially in a phase where light horizons exist, whose outer radii are a few times the star sizes. Moreover, suppose elementary fermions of mass greater than $\sim10^3$ GeV exist, then they may also be surrounded by light horizons with radii comparable to the Higgs Compton wavelength. Finally, nonperturbative states may also be realized in condensed matter systems, wherein phase transitions are controllable using localized sources.
1111.5949
Bastian Kubis
Feng-Kun Guo, Bastian Kubis, Andreas Wirzba
Anomalous decays of eta' and eta into four pions
13 pages, 5 figures; references updated, version published in Phys. Rev. D
Phys.Rev.D85:014014,2012
10.1103/PhysRevD.85.014014
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the branching ratios of the yet unmeasured eta' decays into four pions, based on a combination of chiral perturbation theory and vector-meson dominance. The decays eta' --> 2(pi+ pi-) and eta' --> pi+ pi- 2pi0 are P-wave dominated and can largely be thought to proceed via two rho resonances; we predict branching fractions of (1.0+-0.3)*10^-4 and (2.4+-0.7)*10^-4, respectively, not much lower than the current experimental upper limits. The decays eta' --> 4pi0 and eta --> 4pi0, in contrast, are D-wave driven as long as conservation of CP symmetry is assumed, and are significantly further suppressed; any experimental evidence for the decay eta --> 4pi0 could almost certainly be interpreted as a signal of CP violation. We also calculate the CP-violating amplitudes for eta' --> 4pi0 and eta --> 4pi0 induced by the QCD theta-term.
[ { "created": "Fri, 25 Nov 2011 11:24:56 GMT", "version": "v1" }, { "created": "Fri, 13 Jan 2012 08:30:46 GMT", "version": "v2" } ]
2012-01-16
[ [ "Guo", "Feng-Kun", "" ], [ "Kubis", "Bastian", "" ], [ "Wirzba", "Andreas", "" ] ]
We calculate the branching ratios of the yet unmeasured eta' decays into four pions, based on a combination of chiral perturbation theory and vector-meson dominance. The decays eta' --> 2(pi+ pi-) and eta' --> pi+ pi- 2pi0 are P-wave dominated and can largely be thought to proceed via two rho resonances; we predict branching fractions of (1.0+-0.3)*10^-4 and (2.4+-0.7)*10^-4, respectively, not much lower than the current experimental upper limits. The decays eta' --> 4pi0 and eta --> 4pi0, in contrast, are D-wave driven as long as conservation of CP symmetry is assumed, and are significantly further suppressed; any experimental evidence for the decay eta --> 4pi0 could almost certainly be interpreted as a signal of CP violation. We also calculate the CP-violating amplitudes for eta' --> 4pi0 and eta --> 4pi0 induced by the QCD theta-term.
2202.00266
Fangcheng He
Fangcheng He, Chueng-Ryong Ji, W. Melnitchouk, A. W. Thomas, P. Wang
Generalized parton distributions of sea quarks in the proton from nonlocal chiral effective theory
71 pages, 10 figures
null
10.1103/PhysRevD.106.054006
JLAB-THY-22-3553, ADP-22-1/T1172
hep-ph hep-ex nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
We calculate the spin-averaged generalized parton distributions (GPDs) of sea quarks in the proton at zero skewness from nonlocal covariant chiral effective theory, including one-loop contributions from intermediate states with pseudoscalar mesons and octet and decuplet baryons. A relativistic regulator is generated from the nonlocal Lagrangian where a gauge link is introduced to guarantee local gauge invariance, with additional diagrams from the expansion of the gauge link ensuring conservation of electric charge and strangeness. Flavor asymmetries for sea quarks at zero and finite momentum transfer, as well as strange form factors, are obtained from the calculated GPDs, and results compared with phenomenological extractions and lattice QCD.
[ { "created": "Tue, 1 Feb 2022 07:53:39 GMT", "version": "v1" }, { "created": "Tue, 16 Aug 2022 10:02:51 GMT", "version": "v2" } ]
2022-09-21
[ [ "He", "Fangcheng", "" ], [ "Ji", "Chueng-Ryong", "" ], [ "Melnitchouk", "W.", "" ], [ "Thomas", "A. W.", "" ], [ "Wang", "P.", "" ] ]
We calculate the spin-averaged generalized parton distributions (GPDs) of sea quarks in the proton at zero skewness from nonlocal covariant chiral effective theory, including one-loop contributions from intermediate states with pseudoscalar mesons and octet and decuplet baryons. A relativistic regulator is generated from the nonlocal Lagrangian where a gauge link is introduced to guarantee local gauge invariance, with additional diagrams from the expansion of the gauge link ensuring conservation of electric charge and strangeness. Flavor asymmetries for sea quarks at zero and finite momentum transfer, as well as strange form factors, are obtained from the calculated GPDs, and results compared with phenomenological extractions and lattice QCD.
0805.4063
Hyun-Chul Kim
Tim Ledwig, Hyun-Chul Kim, and Klaus Goeke
Axial-vector transitions and strong decays of the baryon antidecuplet in the self-consistent SU(3) chiral quark-soliton model
27 pages
Phys.Rev.D78:054005,2008
10.1103/PhysRevD.78.054005
INHA-NTG-09/2008
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the axial-vector transition constants of the baryon antidecuplet to the octet and decuplet within the framework of the self-consistent SU(3) chiral quark-soliton model. Taking into account rotational 1/N_c and linear m_s corrections and using the symmetry-conserving quantization, we calculate the axial-vector transition constants. It is found that the leading-order contributions are generally almost canceled by the rotational 1/N_c corrections. Thus, the m_s corrections turn out to be essential contributions to the axial-vector constants. The decay width of the Theta^+ to NK transition is determined to be Gamma(Theta -> NK)=0.71, MeV, based on the result of the axial-vector transition constant g_A^* (Theta -> NK)=0.05. In addition, other strong decays of the baryon antidecuplet are investigated.
[ { "created": "Tue, 27 May 2008 07:25:08 GMT", "version": "v1" } ]
2009-01-09
[ [ "Ledwig", "Tim", "" ], [ "Kim", "Hyun-Chul", "" ], [ "Goeke", "Klaus", "" ] ]
We investigate the axial-vector transition constants of the baryon antidecuplet to the octet and decuplet within the framework of the self-consistent SU(3) chiral quark-soliton model. Taking into account rotational 1/N_c and linear m_s corrections and using the symmetry-conserving quantization, we calculate the axial-vector transition constants. It is found that the leading-order contributions are generally almost canceled by the rotational 1/N_c corrections. Thus, the m_s corrections turn out to be essential contributions to the axial-vector constants. The decay width of the Theta^+ to NK transition is determined to be Gamma(Theta -> NK)=0.71, MeV, based on the result of the axial-vector transition constant g_A^* (Theta -> NK)=0.05. In addition, other strong decays of the baryon antidecuplet are investigated.
hep-ph/0410031
Joao Pacheco B. C. de Melo
J.P.B.C. de Melo (Instituto de Fisica Teorica, IFT, UNESP, SP., Brazil and Centro de Ciencias Exatas e Tecnologicas, Universidade Cruzeiro do Sul, Sao Paulo, SP., Brazil), T. Frederico (Dep. de Fisica, ITA, CTA, Sao Jose dos Campos, SP., Brazil), E. Pace (Dipartimento di Fisica, Universita di Roma Tor Vergata, and INFN Sezione Tor Vergata, Roma, Italy), G. Salme (Universita de Roma I, INFN, Roma, Italy)
The pion electromagnetic form-factor in a QCD-inspired model
Talk given in Light-Cone 2004, Amsterdam,NL., 16-20 August, 2004. To appear in "Few-Body Systems". 4 pages, 2 figues eps, use Few-Body Sytems latex style
Few Body Syst. 36 (2005) 189-193
10.1007/s00601-004-0099-2
null
hep-ph hep-ex nucl-th
null
We present detailed numerical results for the pion space-like electromagnetic form factor obtained within a recently proposed model of the pion electromagnetic current in a confining light-front QCD-inspired model. The model incorporates the vector meson dominance mechanism at the quark level, where the dressed photon with $q^+>0$ decay in an interacting quark-antiquark pair,wich absorbs the initial pion and produces the pion in the final state.
[ { "created": "Sat, 2 Oct 2004 11:45:37 GMT", "version": "v1" }, { "created": "Fri, 15 Apr 2005 20:41:33 GMT", "version": "v2" } ]
2009-11-10
[ [ "de Melo", "J. P. B. C.", "", "Instituto de Fisica Teorica, IFT, UNESP, SP., Brazil\n and Centro de Ciencias Exatas e Tecnologicas, Universidade Cruzeiro do Sul,\n Sao Paulo, SP., Brazil" ], [ "Frederico", "T.", "", "Dep. de Fisica, ITA, CTA, Sao Jose dos\n Campos, SP., Brazil" ], [ "Pace", "E.", "", "Dipartimento di Fisica, Universita di Roma Tor\n Vergata, and INFN Sezione Tor Vergata, Roma, Italy" ], [ "Salme", "G.", "", "Universita de\n Roma I, INFN, Roma, Italy" ] ]
We present detailed numerical results for the pion space-like electromagnetic form factor obtained within a recently proposed model of the pion electromagnetic current in a confining light-front QCD-inspired model. The model incorporates the vector meson dominance mechanism at the quark level, where the dressed photon with $q^+>0$ decay in an interacting quark-antiquark pair,wich absorbs the initial pion and produces the pion in the final state.
hep-ph/9310244
null
D.A. Morris, T.N. Truong and D. Zappala
Higgs Boson Interference in $\gamma \gamma \rightarrow W^+W^-$
8 pages (LaTeX) + 5 PostScript figures in accompanying file (uuencoded), figures also available by fax upon request to reyes@uclaph.bitnet, UCLA/TEP/93/35
Phys.Lett. B323 (1994) 421-426
10.1016/0370-2693(94)91241-6
null
hep-ph
null
We study interference effects between resonant and nonresonant amplitudes for the $\gamma \gamma \rightarrow W^+ W^-$ process at a backscattered photon-photon collider. We show that a Higgs boson with $M_H$ > 200 GeV is manifest as a resonant dip in the $W^+W^-$ invariant mass spectrum and we investigate its statistical significance.
[ { "created": "Thu, 7 Oct 1993 21:26:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Morris", "D. A.", "" ], [ "Truong", "T. N.", "" ], [ "Zappala", "D.", "" ] ]
We study interference effects between resonant and nonresonant amplitudes for the $\gamma \gamma \rightarrow W^+ W^-$ process at a backscattered photon-photon collider. We show that a Higgs boson with $M_H$ > 200 GeV is manifest as a resonant dip in the $W^+W^-$ invariant mass spectrum and we investigate its statistical significance.
2208.04388
Maria Vittoria Garzelli
G. Bevilacqua, M. V. Garzelli, A. Kardos, L. Toth
$W$ + charm associated hadroproduction: relevance of Shower Monte Carlo effects
5 pages, 2 figures. Poster Presented at DIS2022: XXIX International Workshop on Deep-Inelastic Scattering and Related Subjects, Santiago de Compostela, Spain, May 2-6 2022
null
10.5281/zenodo.7410921
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Data on $W + D$-meson and $W + c$-jet hadroproduction have recently started to be included in at least some of the parton distribution function fits, mainly because of their potential to constrain the strange quark content of the proton. In this contribution we present predictions for $W + D$-meson and $W + c$-jet production with NLO QCD accuracy matched to parton shower. We show how including the latter effects, as well as hadronization, beam remnant and multiple parton interaction effects present in Shower Monte Carlo codes, is fundamental to provide consistent comparisons with the current experimental data by the ATLAS and CMS collaborations, as required for non-biased extractions of the strange and antistrange quark PDFs.
[ { "created": "Mon, 8 Aug 2022 19:57:45 GMT", "version": "v1" } ]
2023-01-30
[ [ "Bevilacqua", "G.", "" ], [ "Garzelli", "M. V.", "" ], [ "Kardos", "A.", "" ], [ "Toth", "L.", "" ] ]
Data on $W + D$-meson and $W + c$-jet hadroproduction have recently started to be included in at least some of the parton distribution function fits, mainly because of their potential to constrain the strange quark content of the proton. In this contribution we present predictions for $W + D$-meson and $W + c$-jet production with NLO QCD accuracy matched to parton shower. We show how including the latter effects, as well as hadronization, beam remnant and multiple parton interaction effects present in Shower Monte Carlo codes, is fundamental to provide consistent comparisons with the current experimental data by the ATLAS and CMS collaborations, as required for non-biased extractions of the strange and antistrange quark PDFs.
hep-ph/0012152
Hai-Yang Cheng
Hai-Yang Cheng and Kwei-Chou Yang
Analysis of B-> \phi K Decays in QCD Factorization
13 pages, 3 figures. A major change for the presentation of branching-ratio predictions. Experimental data are updated
Phys.Rev. D64 (2001) 074004
10.1103/PhysRevD.64.074004
null
hep-ph hep-ex
null
We analyze the decay $B\to \phi K$ within the framework of QCD-improved factorization. We found that although the twist-3 kaon distribution amplitude dominates the spectator interactions, it will suppress the decay rates slightly. The weak annihilation diagrams induced by $(S-P)(S+P)$ penguin operators, which are formally power-suppressed by order $(\Lambda/m_b)^2$, are chirally and logarithmically enhanced. Therefore, these annihilation contributions are not subject to helicity suppression and can be sizable. The predicted branching ratio of $B^-\to\phi K^-$ is $(3.8\pm0.6)\times 10^{-6}$ in the absence of annihilation contributions and it becomes $(4.3^{+3.0}_{-1.4})\times 10^{-6}$ when annihilation effects are taken into account. The prediction is consistent with CLEO and BaBar data but smaller than the BELLE result.
[ { "created": "Wed, 13 Dec 2000 16:18:48 GMT", "version": "v1" }, { "created": "Fri, 9 Feb 2001 16:24:07 GMT", "version": "v2" }, { "created": "Wed, 9 May 2001 20:00:49 GMT", "version": "v3" } ]
2009-10-31
[ [ "Cheng", "Hai-Yang", "" ], [ "Yang", "Kwei-Chou", "" ] ]
We analyze the decay $B\to \phi K$ within the framework of QCD-improved factorization. We found that although the twist-3 kaon distribution amplitude dominates the spectator interactions, it will suppress the decay rates slightly. The weak annihilation diagrams induced by $(S-P)(S+P)$ penguin operators, which are formally power-suppressed by order $(\Lambda/m_b)^2$, are chirally and logarithmically enhanced. Therefore, these annihilation contributions are not subject to helicity suppression and can be sizable. The predicted branching ratio of $B^-\to\phi K^-$ is $(3.8\pm0.6)\times 10^{-6}$ in the absence of annihilation contributions and it becomes $(4.3^{+3.0}_{-1.4})\times 10^{-6}$ when annihilation effects are taken into account. The prediction is consistent with CLEO and BaBar data but smaller than the BELLE result.
1003.3843
Elizabeth Rodriguez Querts
H. P\'erez Rojas and E. Rodriguez Querts
Photon Redshift in a Magnetic field
null
null
10.1142/S0218301311040761
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Previous results from the authors concerning the arising a tiny photon anomalous paramagnetic moment are also interpreted as a red-shift in analogy to the gravitational known effect. It is due to the photon interaction with the magnetized virtual electron-positron background which withdraw transverse momentum from photons and is polarization-dependent. If the photon frequency red-shift implies a change in time, a clock would go faster for increasing magnetic field intensity.
[ { "created": "Fri, 19 Mar 2010 17:08:03 GMT", "version": "v1" } ]
2015-05-18
[ [ "Rojas", "H. Pérez", "" ], [ "Querts", "E. Rodriguez", "" ] ]
Previous results from the authors concerning the arising a tiny photon anomalous paramagnetic moment are also interpreted as a red-shift in analogy to the gravitational known effect. It is due to the photon interaction with the magnetized virtual electron-positron background which withdraw transverse momentum from photons and is polarization-dependent. If the photon frequency red-shift implies a change in time, a clock would go faster for increasing magnetic field intensity.
1202.2894
Haipeng An
Haipeng An, Xiangdong Ji and Lian-Tao Wang
Light dark matter and $Z'$ dark force at colliders
23 pages and 14 figures
null
10.1007/JHEP07(2012)182
PI-PARTPHYS-258, UMD-DOE/ER/40762-514
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Light Dark Matter, $<10$ GeV, with sizable direct detection rate is an interesting and less explored scenario. Collider searches can be very powerful, such as through the channel in which a pair of dark matter particle are produced in association with a jet. It is a generic possibility that the mediator of the interaction between DM and the nucleus will also be accessible at the Tevatron and the LHC. Therefore, collider search of the mediator can provide a more comprehensive probe of the dark matter and its interactions. In this article, to demonstrate the complementarity of these two approaches, we focus on the possibility of the mediator being a new $U(1)'$ gauge boson, which is probably the simplest model which allows a large direct detection cross section for a light dark matter candidate. We combine searches in the monojet+MET channel and dijet resonance search for the mediator. We find that for the mass of $Z'$ between 250 GeV and 4 TeV, resonance searches at the colliders provide stronger constraints on this model than the monojet+MET searches.
[ { "created": "Mon, 13 Feb 2012 23:19:07 GMT", "version": "v1" } ]
2015-06-04
[ [ "An", "Haipeng", "" ], [ "Ji", "Xiangdong", "" ], [ "Wang", "Lian-Tao", "" ] ]
Light Dark Matter, $<10$ GeV, with sizable direct detection rate is an interesting and less explored scenario. Collider searches can be very powerful, such as through the channel in which a pair of dark matter particle are produced in association with a jet. It is a generic possibility that the mediator of the interaction between DM and the nucleus will also be accessible at the Tevatron and the LHC. Therefore, collider search of the mediator can provide a more comprehensive probe of the dark matter and its interactions. In this article, to demonstrate the complementarity of these two approaches, we focus on the possibility of the mediator being a new $U(1)'$ gauge boson, which is probably the simplest model which allows a large direct detection cross section for a light dark matter candidate. We combine searches in the monojet+MET channel and dijet resonance search for the mediator. We find that for the mass of $Z'$ between 250 GeV and 4 TeV, resonance searches at the colliders provide stronger constraints on this model than the monojet+MET searches.
1507.01412
Diego Guadagnoli
Diego Guadagnoli, Kenneth Lane
Charged-Lepton Mixing and Lepton Flavor Violation
13 pages, 1 figure. v3: predicted rates involving tau-leptons corrected for phase space; added textual comparison of our predictions with existing literature; other minor textual corrections. Matches journal version
null
10.1016/j.physletb.2015.10.010
CERN-PH-TH-2015-153, LAPTH-037/15
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model for calculating charged-lepton mixing matrices. These matrices are an essential ingredient for predicting lepton flavor-violating rates in the lepton number nonuniversal models recently proposed to explain anomalies in B-meson decays. The model is based on work on "constrained flavor breaking" by Appelquist, Bai and Piai relating the charged-lepton mass matrix, M_l, to those for the up and down-type quarks, M_{u,d}. We use our recent model of lepton nonuniversality to illustrate the magnitudes of flavor-violating B-decay rates that might be expected. Decays with mu tau final states generally have the highest rates by far.
[ { "created": "Mon, 6 Jul 2015 12:17:26 GMT", "version": "v1" }, { "created": "Thu, 16 Jul 2015 13:55:29 GMT", "version": "v2" }, { "created": "Thu, 15 Oct 2015 14:19:19 GMT", "version": "v3" } ]
2015-10-21
[ [ "Guadagnoli", "Diego", "" ], [ "Lane", "Kenneth", "" ] ]
We present a model for calculating charged-lepton mixing matrices. These matrices are an essential ingredient for predicting lepton flavor-violating rates in the lepton number nonuniversal models recently proposed to explain anomalies in B-meson decays. The model is based on work on "constrained flavor breaking" by Appelquist, Bai and Piai relating the charged-lepton mass matrix, M_l, to those for the up and down-type quarks, M_{u,d}. We use our recent model of lepton nonuniversality to illustrate the magnitudes of flavor-violating B-decay rates that might be expected. Decays with mu tau final states generally have the highest rates by far.
2309.11546
Rebeca Beltran
Rebeca Beltr\'an, Julian G\"unther, Martin Hirsch, Arsenii Titov, Zeren Simon Wang
Heavy neutral leptons from kaons in effective field theory
Sensitivity curves for DUNE-ND added in the plots. Paper accepted for publication in PRD
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the framework of the low-energy effective theory containing in addition to the Standard Model fields heavy neutral leptons (HNLs), we compute the decay rates of neutral and charged kaons into HNLs. We consider both lepton-number-conserving and lepton-number-violating four-fermion operators, taking into account also the contribution of active-heavy neutrino mixing. Assuming that the produced HNLs are long-lived, we perform simulations and calculate the sensitivities of future long-lived-particle (LLP) detectors at the high-luminosity LHC as well as the near detector of the Deep Underground Neutrino Experiment (DUNE-ND) to the considered scenario. When applicable, we also recast the existing bounds on the minimal mixing case obtained by NA62, T2K, and PS191. Our findings show that while the future LHC LLP detectors can probe currently allowed parameter space only in certain benchmark scenarios, DUNE-ND should be sensitive to parameter space beyond the current bounds in almost all the benchmark scenarios and for some of the effective operators considered it can even probe new-physics scales in excess of 3000 TeV.
[ { "created": "Wed, 20 Sep 2023 18:00:02 GMT", "version": "v1" }, { "created": "Thu, 26 Oct 2023 08:34:27 GMT", "version": "v2" }, { "created": "Wed, 22 May 2024 12:48:57 GMT", "version": "v3" } ]
2024-05-24
[ [ "Beltrán", "Rebeca", "" ], [ "Günther", "Julian", "" ], [ "Hirsch", "Martin", "" ], [ "Titov", "Arsenii", "" ], [ "Wang", "Zeren Simon", "" ] ]
In the framework of the low-energy effective theory containing in addition to the Standard Model fields heavy neutral leptons (HNLs), we compute the decay rates of neutral and charged kaons into HNLs. We consider both lepton-number-conserving and lepton-number-violating four-fermion operators, taking into account also the contribution of active-heavy neutrino mixing. Assuming that the produced HNLs are long-lived, we perform simulations and calculate the sensitivities of future long-lived-particle (LLP) detectors at the high-luminosity LHC as well as the near detector of the Deep Underground Neutrino Experiment (DUNE-ND) to the considered scenario. When applicable, we also recast the existing bounds on the minimal mixing case obtained by NA62, T2K, and PS191. Our findings show that while the future LHC LLP detectors can probe currently allowed parameter space only in certain benchmark scenarios, DUNE-ND should be sensitive to parameter space beyond the current bounds in almost all the benchmark scenarios and for some of the effective operators considered it can even probe new-physics scales in excess of 3000 TeV.
1409.8059
Ambresh Shivaji
Pankaj Agrawal and Ambresh Shivaji
Gluon Fusion Contribution to $VHj$ Production at Hadron Colliders
12 pages, 6 figures, 2 tables. Version to appear in PLB
Phys.Lett. B741 (2015) 111-116
10.1016/j.physletb.2014.12.021
RECAPP-HRI-2014-020
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the associated production of an electroweak vector boson and the Higgs boson with a jet via gluon-gluon fusion. At the leading order, these processes occur at one-loop level. The amplitudes of these one-loop processes are gauge invariant and finite. Therefore, their contributions towards the corresponding hadronic cross sections and kinematic distributions can be calculated separately. We present results for the Large Hadron Collider and its discussed upgrades. We find that the gluon-gluon one-loop process gives dominant contribution to the $\gamma H j$ production. We observe a destructive interference effect in the $gg\to Z H j$ amplitude. We also find that in the high transverse momentum and central rapidity region, the $ZHj$ production cross section via gluon-gluon fusion becomes comparable to the cross section contributions coming from quark-quark and quark-gluon channels.
[ { "created": "Mon, 29 Sep 2014 10:29:44 GMT", "version": "v1" }, { "created": "Mon, 8 Dec 2014 20:35:37 GMT", "version": "v2" } ]
2018-05-09
[ [ "Agrawal", "Pankaj", "" ], [ "Shivaji", "Ambresh", "" ] ]
We study the associated production of an electroweak vector boson and the Higgs boson with a jet via gluon-gluon fusion. At the leading order, these processes occur at one-loop level. The amplitudes of these one-loop processes are gauge invariant and finite. Therefore, their contributions towards the corresponding hadronic cross sections and kinematic distributions can be calculated separately. We present results for the Large Hadron Collider and its discussed upgrades. We find that the gluon-gluon one-loop process gives dominant contribution to the $\gamma H j$ production. We observe a destructive interference effect in the $gg\to Z H j$ amplitude. We also find that in the high transverse momentum and central rapidity region, the $ZHj$ production cross section via gluon-gluon fusion becomes comparable to the cross section contributions coming from quark-quark and quark-gluon channels.
hep-ph/0310166
Shunzo Kumano
S. Kumano (Saga University)
Neutrino Scattering Physics at Superbeams and Neutrino Factories
1+8 pages, LaTeX2e, 6 figures. Plenary talk at the 5th International Workshop on Neutrino Factories and Superbeams, Columbia University, New York, USA, June 5-11, 2003. To be published in AIP proceedings. Group web page at http://hs.phys.saga-u.ac.jp
null
10.1063/1.1818374
SAGA-HE-198-03
hep-ph hep-ex nucl-ex nucl-th
null
Neutrino scattering physics is discussed for investigating internal structure of the nucleon and nuclei at future neutrino facilities. We explain structure functions in neutrino scattering. In particular, there are new polarized functions g_3, g_4, and g_5, and they should provide us important information for determining internal nucleon spin structure. Next, nuclear structure functions are discussed. From F_3 structure function measurements, valence-quark shadowing should be clarified. Nuclear effects on the NuTeV sin^2\theta_W anomaly are explained. We also comment on low-energy neutrino scattering, which is relevant to current long-baseline neutrino oscillation experiments.
[ { "created": "Tue, 14 Oct 2003 09:32:26 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kumano", "S.", "", "Saga University" ] ]
Neutrino scattering physics is discussed for investigating internal structure of the nucleon and nuclei at future neutrino facilities. We explain structure functions in neutrino scattering. In particular, there are new polarized functions g_3, g_4, and g_5, and they should provide us important information for determining internal nucleon spin structure. Next, nuclear structure functions are discussed. From F_3 structure function measurements, valence-quark shadowing should be clarified. Nuclear effects on the NuTeV sin^2\theta_W anomaly are explained. We also comment on low-energy neutrino scattering, which is relevant to current long-baseline neutrino oscillation experiments.
hep-ph/9612253
null
J. A. Grifols, R. N. Mohapatra and A. Riotto
New Astrophysical Constraints on the Mass of the Superlight Gravitino
4 pages; latex; no figures; Report No. UMD-PP-97-62; FERMILAB-Pub- 96/433-A; UAB-FT-406
Phys.Lett. B400 (1997) 124-128
10.1016/S0370-2693(97)00348-1
null
hep-ph astro-ph
null
In some supergravity models, the superlight gravitino is accompanied by a light weakly coupled scalar (S) and pseudo-scalar (P) particle. The coupling of these particles to matter is inversely proportional to the product of the gravitino mass and the Planck mass. As a result, their emission from the stars and supernovae via the photon electron scattering reaction for certain ranges of the gravitino mass can become the dominant energy loss mechanism in contradiction with observations thereby ruling out those mass values for the gravitino. For scalar and/or pseudo-scalar masses between 10 MeV and a keV, the SN1987A observations exclude the gravitino mass range from 0.03 eV to 30 eV whereas if the S/P masses are less than a keV, constraints of stellar energy loss can exclude the gravitino masses ranging from $3\times 10^{-6}$ eV to 50 eV for the photino mass of 100 GeV. We also find that for S/P mass less than an MeV, Big Bang Nucleosynthesis constraints imply a gravitino mass larger than one eV. These are the most stringent bounds to date on the gravitino mass in this class of models.
[ { "created": "Wed, 4 Dec 1996 17:15:53 GMT", "version": "v1" }, { "created": "Thu, 5 Dec 1996 17:06:12 GMT", "version": "v2" } ]
2009-10-30
[ [ "Grifols", "J. A.", "" ], [ "Mohapatra", "R. N.", "" ], [ "Riotto", "A.", "" ] ]
In some supergravity models, the superlight gravitino is accompanied by a light weakly coupled scalar (S) and pseudo-scalar (P) particle. The coupling of these particles to matter is inversely proportional to the product of the gravitino mass and the Planck mass. As a result, their emission from the stars and supernovae via the photon electron scattering reaction for certain ranges of the gravitino mass can become the dominant energy loss mechanism in contradiction with observations thereby ruling out those mass values for the gravitino. For scalar and/or pseudo-scalar masses between 10 MeV and a keV, the SN1987A observations exclude the gravitino mass range from 0.03 eV to 30 eV whereas if the S/P masses are less than a keV, constraints of stellar energy loss can exclude the gravitino masses ranging from $3\times 10^{-6}$ eV to 50 eV for the photino mass of 100 GeV. We also find that for S/P mass less than an MeV, Big Bang Nucleosynthesis constraints imply a gravitino mass larger than one eV. These are the most stringent bounds to date on the gravitino mass in this class of models.
hep-ph/9903476
Erler
Jens Erler and Paul Langacker
Constraints on Extended Neutral Gauge Structures
13 pages of LaTeX2e, 6 figures
Phys.Lett.B456:68-76,1999
10.1016/S0370-2693(99)00457-8
UPR-839-T
hep-ph
null
Indirect precision data are used to constrain the masses of possible extra Z^prime bosons and their mixings with the ordinary Z. We study a variety of Z^prime bosons as they appear in E_6 and left-right unification models, the sequential Z boson, and the example of an additional U(1) in a concrete model from heterotic string theory. In all cases the mixings are severely constrained (sin theta < 0.01). The lower mass limits are generally of the order of several hundred GeV and competitive with collider bounds. The exception is the Z_psi boson, whose vector couplings vanish and whose limits are weaker. The results change little when the rho parameter is allowed, which corresponds to a completely arbitrary Higgs sector. On the other hand, in specific models with minimal Higgs structures the limits are generally pushed into the TeV region.
[ { "created": "Wed, 24 Mar 1999 18:42:46 GMT", "version": "v1" } ]
2008-11-26
[ [ "Erler", "Jens", "" ], [ "Langacker", "Paul", "" ] ]
Indirect precision data are used to constrain the masses of possible extra Z^prime bosons and their mixings with the ordinary Z. We study a variety of Z^prime bosons as they appear in E_6 and left-right unification models, the sequential Z boson, and the example of an additional U(1) in a concrete model from heterotic string theory. In all cases the mixings are severely constrained (sin theta < 0.01). The lower mass limits are generally of the order of several hundred GeV and competitive with collider bounds. The exception is the Z_psi boson, whose vector couplings vanish and whose limits are weaker. The results change little when the rho parameter is allowed, which corresponds to a completely arbitrary Higgs sector. On the other hand, in specific models with minimal Higgs structures the limits are generally pushed into the TeV region.
1210.4941
Alexandros Kehagias
Fotis Farakos and Alex Kehagias
Non-Linear Single Higgs MSSM
21 pages, 1 figure
null
10.1016/j.physletb.2012.12.040
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a non-linear MSSM with non-standard Higgs sector and goldstino field. Non-linear supersymmetry for the goldstino couplings is described by the constrained chiral superfield and, as usual, the Standard Model sector is encompassed in suitable chiral and vector supermultiplets. Two models are presented. In the first model (non-linear MSSM$3 1/2$), the second Higgs is replaced by a new supermultiplet of half-family with only a new generation of leptons (or quarks). In the second model, for anomaly cancellation purposes, the second Higgs is retained as a spectator superfield by imposing a discrete symmetry. Both models do not have a $\mu$-problem as a $\mu$-term is forbidden by the discrete symmetry in the case of a spectator second Higgs or not existing at all in the case of a single Higgs. Moreover, the tree level relation between the Higgs mass and the hidden sector SUSY breaking scale $\sqrt{f}$ is derived. Finally, we point out a relative suppression by $m_{soft}/\Lambda$ of the bottom and tau Yukawa couplings with respect to those of the top quark.
[ { "created": "Wed, 17 Oct 2012 20:04:21 GMT", "version": "v1" } ]
2015-06-11
[ [ "Farakos", "Fotis", "" ], [ "Kehagias", "Alex", "" ] ]
We present a non-linear MSSM with non-standard Higgs sector and goldstino field. Non-linear supersymmetry for the goldstino couplings is described by the constrained chiral superfield and, as usual, the Standard Model sector is encompassed in suitable chiral and vector supermultiplets. Two models are presented. In the first model (non-linear MSSM$3 1/2$), the second Higgs is replaced by a new supermultiplet of half-family with only a new generation of leptons (or quarks). In the second model, for anomaly cancellation purposes, the second Higgs is retained as a spectator superfield by imposing a discrete symmetry. Both models do not have a $\mu$-problem as a $\mu$-term is forbidden by the discrete symmetry in the case of a spectator second Higgs or not existing at all in the case of a single Higgs. Moreover, the tree level relation between the Higgs mass and the hidden sector SUSY breaking scale $\sqrt{f}$ is derived. Finally, we point out a relative suppression by $m_{soft}/\Lambda$ of the bottom and tau Yukawa couplings with respect to those of the top quark.