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hep-ph/9409299
Judah M. Eisenberg
G. Kaelbermann, J.M. Eisenberg, Andreas Schaefer
Proton spin content from skyrmions
8 pages
Phys.Lett.B339:211-214,1994
10.1016/0370-2693(94)90633-5
null
hep-ph nucl-th
null
It is well known that in lowest order the skyrmion model of the nucleon gives vanishing spin content. With new data indicating a proton spin content $\Delta\Sigma = 0.22\pm 0.14,$ it is an increasing challenge to find ways in which the skyrmion can move away from the null result. We show here that a particular term in the skyrmion lagrangian in SU(3) involving six derivatives of the field can, with plausible parameters, yield a spin content consistent with present experiment.
[ { "created": "Tue, 13 Sep 1994 12:52:03 GMT", "version": "v1" } ]
2011-07-19
[ [ "Kaelbermann", "G.", "" ], [ "Eisenberg", "J. M.", "" ], [ "Schaefer", "Andreas", "" ] ]
It is well known that in lowest order the skyrmion model of the nucleon gives vanishing spin content. With new data indicating a proton spin content $\Delta\Sigma = 0.22\pm 0.14,$ it is an increasing challenge to find ways in which the skyrmion can move away from the null result. We show here that a particular term in the skyrmion lagrangian in SU(3) involving six derivatives of the field can, with plausible parameters, yield a spin content consistent with present experiment.
hep-ph/0009258
Jens Ole Schmitt
Jens Ole Schmitt, Gouranga C. Nayak, Horst Stoecker and Walter Greiner
Bottom and Charm Production at LHC and RHIC
8 pages latex (single spaced), 4 postscript figures, title changed, minor modifications, submitted to PLB
Phys.Lett.B498:163-168,2001
10.1016/S0370-2693(00)01340-X
null
hep-ph nucl-th
null
We study $b\bar{b}$ and $c\bar{c}$ production and the influence of nuclear shadowing at LHC and RHIC energies. We find a significant reduction in the production cross section of both charm and bottom at RHIC and LHC. Bound states such as $\Upsilon$ and $J/\Psi$ are suppressed by this reduction in the charm production cross sections. Therefore, $J/\Psi$ suppression may not be useful as a signature for the quark gluon plasma.
[ { "created": "Thu, 21 Sep 2000 18:23:46 GMT", "version": "v1" }, { "created": "Sat, 11 Nov 2000 18:29:35 GMT", "version": "v2" } ]
2011-01-25
[ [ "Schmitt", "Jens Ole", "" ], [ "Nayak", "Gouranga C.", "" ], [ "Stoecker", "Horst", "" ], [ "Greiner", "Walter", "" ] ]
We study $b\bar{b}$ and $c\bar{c}$ production and the influence of nuclear shadowing at LHC and RHIC energies. We find a significant reduction in the production cross section of both charm and bottom at RHIC and LHC. Bound states such as $\Upsilon$ and $J/\Psi$ are suppressed by this reduction in the charm production cross sections. Therefore, $J/\Psi$ suppression may not be useful as a signature for the quark gluon plasma.
2107.07132
Mikko Laine
G. Jackson and M. Laine
Efficient numerical integration of thermal interaction rates
48 pages, programs as ancillary files. v2: clarifications added
JHEP 09 (2021) 125
10.1007/JHEP09(2021)125
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many problems in particle cosmology, interaction rates are dominated by ${2}\leftrightarrow{2}$ scatterings, or get a substantial contribution from them, given that ${1}\leftrightarrow{2}$ and ${1}\leftrightarrow{3}$ reactions are phase-space suppressed. We describe an algorithm to represent, regularize, and evaluate a class of thermal ${2}\leftrightarrow{2}$ and ${1}\leftrightarrow{3}$ interaction rates for general momenta, masses, chemical potentials, and helicity projections. A key ingredient is an automated inclusion of virtual corrections to ${1}\leftrightarrow{2}$ scatterings, which eliminate logarithmic and double-logarithmic IR divergences from the real ${2}\leftrightarrow{2}$ and ${1}\leftrightarrow{3}$ processes. We also review thermal and chemical potential induced contributions that require resummation if plasma particles are ultrarelativistic.
[ { "created": "Thu, 15 Jul 2021 05:34:19 GMT", "version": "v1" }, { "created": "Fri, 24 Sep 2021 08:11:20 GMT", "version": "v2" } ]
2021-09-27
[ [ "Jackson", "G.", "" ], [ "Laine", "M.", "" ] ]
In many problems in particle cosmology, interaction rates are dominated by ${2}\leftrightarrow{2}$ scatterings, or get a substantial contribution from them, given that ${1}\leftrightarrow{2}$ and ${1}\leftrightarrow{3}$ reactions are phase-space suppressed. We describe an algorithm to represent, regularize, and evaluate a class of thermal ${2}\leftrightarrow{2}$ and ${1}\leftrightarrow{3}$ interaction rates for general momenta, masses, chemical potentials, and helicity projections. A key ingredient is an automated inclusion of virtual corrections to ${1}\leftrightarrow{2}$ scatterings, which eliminate logarithmic and double-logarithmic IR divergences from the real ${2}\leftrightarrow{2}$ and ${1}\leftrightarrow{3}$ processes. We also review thermal and chemical potential induced contributions that require resummation if plasma particles are ultrarelativistic.
hep-ph/0512139
Alexander Kartavtsev
E. A. Paschos, A. Kartavtsev, G.J. Gounaris
Coherent pion production by neutrinos on nuclei
18 pages, 4 figures
Phys.Rev.D74:054007,2006
10.1103/PhysRevD.74.054007
DO-TH 06/03
hep-ph
null
The main part of coherent pion production by neutrinos on nuclei is essentially determined by PCAC, provided that the leptonic momentum transferred square Q^2 remains sufficiently small. We give the formulas for the charged and neutral current cross sections, including also the small non-PCAC transverse current contributions and taking into account the effect of the \mu^- mass. Our results are compared with the experimental ones and other theoretical treatments.
[ { "created": "Mon, 12 Dec 2005 10:25:55 GMT", "version": "v1" }, { "created": "Thu, 29 Dec 2005 16:23:58 GMT", "version": "v2" }, { "created": "Wed, 28 Jun 2006 13:24:26 GMT", "version": "v3" }, { "created": "Wed, 23 Aug 2006 09:35:42 GMT", "version": "v4" } ]
2008-11-26
[ [ "Paschos", "E. A.", "" ], [ "Kartavtsev", "A.", "" ], [ "Gounaris", "G. J.", "" ] ]
The main part of coherent pion production by neutrinos on nuclei is essentially determined by PCAC, provided that the leptonic momentum transferred square Q^2 remains sufficiently small. We give the formulas for the charged and neutral current cross sections, including also the small non-PCAC transverse current contributions and taking into account the effect of the \mu^- mass. Our results are compared with the experimental ones and other theoretical treatments.
1701.05379
Roc\'io del Rey Bajo
I. Brivio, M.B. Gavela, L. Merlo, K. Mimasu, J.M. No, R. del Rey, V.Sanz
ALPs Effective Field Theory and Collider Signatures
66 pages, 15 figures; Version accepted for publication in EPJC
null
10.1140/epjc/s10052-017-5111-3
IFT-UAM/CSIC-16-141, KCL-PH-TH/2016-72, FTUAM-16-49, CP3-17-04
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the leading effective interactions between the Standard Model fields and a generic singlet CP-odd (pseudo)Goldstone boson. Two possible frameworks for electroweak symmetry breaking are considered: linear and non-linear. For the latter case, the basis of leading effective operators is determined and compared with that for the linear expansion. Associated phenomenological signals at colliders are explored for both scenarios, deriving new bounds and analyzing future prospects, including LHC and High Luminosity LHC sensitivities. Mono-$Z$, mono-$W$, $W$-photon plus missing energy and on-shell top final states are most promising signals expected in both frameworks. In addition, non-standard Higgs decays and mono-Higgs signatures are especially prominent and expected to be dominant in non-linear realizations.
[ { "created": "Thu, 19 Jan 2017 11:54:16 GMT", "version": "v1" }, { "created": "Tue, 31 Jan 2017 22:13:47 GMT", "version": "v2" }, { "created": "Thu, 7 Sep 2017 11:43:09 GMT", "version": "v3" } ]
2017-09-13
[ [ "Brivio", "I.", "" ], [ "Gavela", "M. B.", "" ], [ "Merlo", "L.", "" ], [ "Mimasu", "K.", "" ], [ "No", "J. M.", "" ], [ "del Rey", "R.", "" ], [ "Sanz", "V.", "" ] ]
We study the leading effective interactions between the Standard Model fields and a generic singlet CP-odd (pseudo)Goldstone boson. Two possible frameworks for electroweak symmetry breaking are considered: linear and non-linear. For the latter case, the basis of leading effective operators is determined and compared with that for the linear expansion. Associated phenomenological signals at colliders are explored for both scenarios, deriving new bounds and analyzing future prospects, including LHC and High Luminosity LHC sensitivities. Mono-$Z$, mono-$W$, $W$-photon plus missing energy and on-shell top final states are most promising signals expected in both frameworks. In addition, non-standard Higgs decays and mono-Higgs signatures are especially prominent and expected to be dominant in non-linear realizations.
1301.2336
Jason Evans
Biplob Bhattacherjee, Jason L. Evans, Masahiro Ibe, Shigeki Matsumoto, and Tsutomu T. Yanagida
Natural SUSY's Last Hope: R-parity Violation via UDD Operators
null
null
10.1103/PhysRevD.87.115002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Here, we give a broad overview of the more natural spectra allowed by the LHC when UDD R-parity violation is allowed. Because R-parity violation removes the missing energy signals in colliders, the experimental constraints on the gluino, stops, sbottoms and higgsinos are relatively mild. We also show that UDD R-parity violation and lepton number conservation can be made consistent with grand unification. This feat is achieved through the product unification, SU(5) X U(3). In this model, mixing of the SM quarks with additional quark like particles charged under the U(3) generate a UDD R-parity violating operator. Furthermore, these models are also capable of generating a "natural" spectra. The emergence of these more natural low-scale spectra relies heavily on the fact that the gaugino masses are non-universal, a natural consequence of product unification.
[ { "created": "Thu, 10 Jan 2013 21:31:52 GMT", "version": "v1" } ]
2015-06-12
[ [ "Bhattacherjee", "Biplob", "" ], [ "Evans", "Jason L.", "" ], [ "Ibe", "Masahiro", "" ], [ "Matsumoto", "Shigeki", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
Here, we give a broad overview of the more natural spectra allowed by the LHC when UDD R-parity violation is allowed. Because R-parity violation removes the missing energy signals in colliders, the experimental constraints on the gluino, stops, sbottoms and higgsinos are relatively mild. We also show that UDD R-parity violation and lepton number conservation can be made consistent with grand unification. This feat is achieved through the product unification, SU(5) X U(3). In this model, mixing of the SM quarks with additional quark like particles charged under the U(3) generate a UDD R-parity violating operator. Furthermore, these models are also capable of generating a "natural" spectra. The emergence of these more natural low-scale spectra relies heavily on the fact that the gaugino masses are non-universal, a natural consequence of product unification.
1412.8076
Ludwik Turko
Ludwik Turko
The same key to different doors - temperature puzzles
8 pages, Lecture at the 32th Max-Born-Symposium and HECOLS workshop on "Three Days of Phase Transitions in Compact Stars, Heavy-Ion Collisions and Supernovae", Wroc\l{}aw, Poland, February 17--19, 2014
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The notion of temperature in many body elementary particle processes is in a common use for decades. Thermal models have become simple and universal effective tools to describe particle production -- not only in high energy heavy ion collisions but also in high energy elementary particle collisions. We perform a critical analysis of the temperature concepts in such processes. Although the temperature concept is a very useful tool, nevertheless it should be used with the care, taking into account that usually it is just model dependent fitted parameter.
[ { "created": "Sat, 27 Dec 2014 19:25:47 GMT", "version": "v1" } ]
2014-12-30
[ [ "Turko", "Ludwik", "" ] ]
The notion of temperature in many body elementary particle processes is in a common use for decades. Thermal models have become simple and universal effective tools to describe particle production -- not only in high energy heavy ion collisions but also in high energy elementary particle collisions. We perform a critical analysis of the temperature concepts in such processes. Although the temperature concept is a very useful tool, nevertheless it should be used with the care, taking into account that usually it is just model dependent fitted parameter.
1404.4737
Ryo Takahashi
Naoyuki Haba and Ryo Takahashi
Higgs inflation with singlet scalar dark matter and right-handed neutrino in light of BICEP2
9 pages, 2 figures, final version
Phys. Rev. D 89, 115009 (2014)
10.1103/PhysRevD.89.115009
SU-HET-04-2014
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the Higgs inflation scenario with singlet scalar dark matter and a right-handed neutrino. The singlet scalar and the right-handed neutrino play crucial roles for realizing a suitable plateau of Higgs potential with the center value of the top mass of Tevatron and LHC measurements. This Higgs inflation scenario predicts about a 1 TeV scalar dark matter and an $\mathcal{O}(10^{14})$ GeV right-handed neutrino by use of 125.6 GeV Higgs mass, 173.34 GeV top mass, and a nonminimal gravity coupling $\xi\simeq10.1$. This inflation model is consistent with the recent result of the tensor-to-scalar ratio $r=0.20_{-0.05}^{+0.07}$ by the BICEP2 Collaboration.
[ { "created": "Fri, 18 Apr 2014 10:12:44 GMT", "version": "v1" }, { "created": "Tue, 12 Aug 2014 04:14:43 GMT", "version": "v2" } ]
2014-08-13
[ [ "Haba", "Naoyuki", "" ], [ "Takahashi", "Ryo", "" ] ]
We discuss the Higgs inflation scenario with singlet scalar dark matter and a right-handed neutrino. The singlet scalar and the right-handed neutrino play crucial roles for realizing a suitable plateau of Higgs potential with the center value of the top mass of Tevatron and LHC measurements. This Higgs inflation scenario predicts about a 1 TeV scalar dark matter and an $\mathcal{O}(10^{14})$ GeV right-handed neutrino by use of 125.6 GeV Higgs mass, 173.34 GeV top mass, and a nonminimal gravity coupling $\xi\simeq10.1$. This inflation model is consistent with the recent result of the tensor-to-scalar ratio $r=0.20_{-0.05}^{+0.07}$ by the BICEP2 Collaboration.
hep-ph/9504432
null
A.I. Davydychev and J.B. Tausk
Two-loop vacuum diagrams and tensor decomposition
7 pages, plain LaTex, no figures; ps file available by anonymous ftp at ftp://vsfys1.fi.uib.no/anonymous/pub/bergen95-06.ps ; to appear in Proceedings of the AIHENP-95 conference, Pisa, April 1995 (World Scientific, Singapore, 1995)
null
null
Mainz and Bergen preprint MZ-TH-95-13, BERGEN-1995-06
hep-ph hep-th
null
General algorithms for tensor reduction of two-loop massive vacuum diagrams are discussed. Some explicit useful formulae are presented.
[ { "created": "Sat, 29 Apr 1995 19:56:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Davydychev", "A. I.", "" ], [ "Tausk", "J. B.", "" ] ]
General algorithms for tensor reduction of two-loop massive vacuum diagrams are discussed. Some explicit useful formulae are presented.
1209.5022
Andrey Kozhushko
Alexey Gulov, Andrey Kozhushko
Two-parametric model-independent observables for $Z'$ searching at the Tevatron
OBSOLETE VERSION! Please refer to arXiv:1409.1301 for a more recent version with corrected errors. 10 pages, 11 figures, revtex; v2: minor text improvements, references added
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a scheme of searches for the $Z'$ gauge boson as a virtual state in scattering processes at the Tevatron taking into account model-independent relations between the $Z'$ couplings to fermions. We integrate the Drell-Yan process cross setion to construct two-parametric observables, which are suitable for $Z'$ searches in the $p\bar{p} \to l^+ l^-$ process. The observables allow to constrain the $Z'$ vector and axial-vector couplings to SM fermions in a general parameterization with non-universal $Z'$ interactions with fermion generations. Also a one-parametric observable for searching for the popular leptophobic $Z'$ boson is proposed.
[ { "created": "Sat, 22 Sep 2012 22:01:18 GMT", "version": "v1" }, { "created": "Fri, 5 Oct 2012 10:55:05 GMT", "version": "v2" }, { "created": "Sat, 28 Mar 2015 10:34:00 GMT", "version": "v3" } ]
2015-03-31
[ [ "Gulov", "Alexey", "" ], [ "Kozhushko", "Andrey", "" ] ]
We propose a scheme of searches for the $Z'$ gauge boson as a virtual state in scattering processes at the Tevatron taking into account model-independent relations between the $Z'$ couplings to fermions. We integrate the Drell-Yan process cross setion to construct two-parametric observables, which are suitable for $Z'$ searches in the $p\bar{p} \to l^+ l^-$ process. The observables allow to constrain the $Z'$ vector and axial-vector couplings to SM fermions in a general parameterization with non-universal $Z'$ interactions with fermion generations. Also a one-parametric observable for searching for the popular leptophobic $Z'$ boson is proposed.
2102.03989
Hai-Bing Fu
Tao Zhong, Zhi-Hao Zhu, Hai-Bing Fu, Xing-Gang Wu, Tao Huang
An improved light-cone harmonic oscillator model for the pionic leading-twist distribution amplitude
15 pages, 6 figures, matches the version to appear in PRD
Phys. Rev. D 104, 016021 (2021)
10.1103/PhysRevD.104.016021
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we study the pion leading-twist distribution amplitude $\phi_{2;\pi}(x,\mu)$ by improving the traditional light-cone harmonic oscillator model within the reconstruction of the function $\varphi_{2;\pi}(x)$. In order to constraining the model parameters, we calculate its moments $\langle\xi^n\rangle_{2;\pi}|_\mu$ in the framework of QCD background field theory sum rule (BFTSR) up to $10^{\rm th}$ order. Considering the fact that the sum rule of the $0^{\rm th}$ moment $\langle\xi^0\rangle_{2;\pi}|_\mu$ cannot be normalized, we suggest a more reasonable sum rule formula for $\langle\xi^n\rangle_{2;\pi}|_\mu$. Then, we obtain the values of $\langle\xi^n\rangle_{2;\pi}|_{\mu_0}$ with $n=(2,4,6,8,10)$ at the initial scale $\mu_0 = 1~{\rm GeV}$. The first two moments are: $\langle \xi^2\rangle_{2;\pi}|_{\mu_0} = 0.271 \pm 0.013$, $\langle\xi^4\rangle_{2;\pi}|_{\mu_0} = 0.138 \pm 0.010$; and the corresponding Gegenbauer moments are $a^{2;\pi}_2(\mu_0) = 0.206 \pm 0.038$, $a^{2;\pi}_4(\mu_0) = 0.047 \pm 0.011$, respectively. After fitting the moments $\langle\xi^n\rangle_{2;\pi}|_{\mu}$, we obtained the appropriate model parameters by using the least square method. The resultant behavior for twist-2 pion DA is more closely to the AdS/QCD and lattice result, but is narrower than that by Dyson-Schwinger equation. Furthermore, we calculate the pion-photon transition form factors (TFF) and $B\to\pi$ TFF within light-cone sum rule approach, which are conform with experimental and theoretical results.
[ { "created": "Mon, 8 Feb 2021 03:47:42 GMT", "version": "v1" }, { "created": "Tue, 6 Jul 2021 17:41:40 GMT", "version": "v2" } ]
2021-07-28
[ [ "Zhong", "Tao", "" ], [ "Zhu", "Zhi-Hao", "" ], [ "Fu", "Hai-Bing", "" ], [ "Wu", "Xing-Gang", "" ], [ "Huang", "Tao", "" ] ]
In this paper, we study the pion leading-twist distribution amplitude $\phi_{2;\pi}(x,\mu)$ by improving the traditional light-cone harmonic oscillator model within the reconstruction of the function $\varphi_{2;\pi}(x)$. In order to constraining the model parameters, we calculate its moments $\langle\xi^n\rangle_{2;\pi}|_\mu$ in the framework of QCD background field theory sum rule (BFTSR) up to $10^{\rm th}$ order. Considering the fact that the sum rule of the $0^{\rm th}$ moment $\langle\xi^0\rangle_{2;\pi}|_\mu$ cannot be normalized, we suggest a more reasonable sum rule formula for $\langle\xi^n\rangle_{2;\pi}|_\mu$. Then, we obtain the values of $\langle\xi^n\rangle_{2;\pi}|_{\mu_0}$ with $n=(2,4,6,8,10)$ at the initial scale $\mu_0 = 1~{\rm GeV}$. The first two moments are: $\langle \xi^2\rangle_{2;\pi}|_{\mu_0} = 0.271 \pm 0.013$, $\langle\xi^4\rangle_{2;\pi}|_{\mu_0} = 0.138 \pm 0.010$; and the corresponding Gegenbauer moments are $a^{2;\pi}_2(\mu_0) = 0.206 \pm 0.038$, $a^{2;\pi}_4(\mu_0) = 0.047 \pm 0.011$, respectively. After fitting the moments $\langle\xi^n\rangle_{2;\pi}|_{\mu}$, we obtained the appropriate model parameters by using the least square method. The resultant behavior for twist-2 pion DA is more closely to the AdS/QCD and lattice result, but is narrower than that by Dyson-Schwinger equation. Furthermore, we calculate the pion-photon transition form factors (TFF) and $B\to\pi$ TFF within light-cone sum rule approach, which are conform with experimental and theoretical results.
hep-ph/0009273
Akushevich Igor
A.V. Afanasev, I. Akushevich, N.P.Merenkov
Radiative Correction to the Transferred Polarization in Elastic Electron-Proton Scattering
14 pages, 4 figures
Phys.Rev. D65 (2002) 013006
10.1103/PhysRevD.65.013006
null
hep-ph
null
Model independent radiative correction to the recoil proton polarization for the elastic electron-proton scattering is calculated within method of electron structure functions. The explicit expressions for the recoil proton polarization are represented as a contraction of the electron structure and the hard part of the polarization dependent contribution into cross-section. The calculation of the hard part with first order radiative correction is performed. The obtained representation includes the leading radiative corrections in all orders of perturbation theory and the main part of the second order next-to-leading ones. Numerical calculations illustrate our analytical results.
[ { "created": "Fri, 22 Sep 2000 19:26:34 GMT", "version": "v1" }, { "created": "Wed, 6 Dec 2000 18:44:48 GMT", "version": "v2" } ]
2009-10-31
[ [ "Afanasev", "A. V.", "" ], [ "Akushevich", "I.", "" ], [ "Merenkov", "N. P.", "" ] ]
Model independent radiative correction to the recoil proton polarization for the elastic electron-proton scattering is calculated within method of electron structure functions. The explicit expressions for the recoil proton polarization are represented as a contraction of the electron structure and the hard part of the polarization dependent contribution into cross-section. The calculation of the hard part with first order radiative correction is performed. The obtained representation includes the leading radiative corrections in all orders of perturbation theory and the main part of the second order next-to-leading ones. Numerical calculations illustrate our analytical results.
2405.10962
Carolina Sayuri Takeda
Kentaro Kojima, Yuri Okubo, Carolina Sayuri Takeda
Vacuum structure of an eight-dimensional $SU(3)$ gauge theory on a magnetized torus
null
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We analyze the vacuum structure of an eight-dimensional non-abelian gauge theory with a compactified four-dimensional torus as the extra dimensions. As a non-trivial background configuration of the gauge field of an $SU(n)$ gauge group, we suppose a magnetic flux in two extra dimensions, and continuous Wilson line phases are also involved. We introduce matter fields and calculate the mass spectrum of low-energy modes appearing in a four-dimensional effective theory in an $SU(3)$ model as an explicit example. As expected, potentially tachyonic states in four-dimensional modes appear from extra-dimensional gauge fields that couple to the flux background since the gauge group is simply connected. The Wilson line phases give a non-vanishing contribution to their masses, and we have a low-energy mass spectrum without tachyonic states, given that these phases take an appropriate value. To verify the validity of the values of the Wilson line phases, we examine the one-loop effective potential for these phases and explicitly show the contribution from each type of field present in our model. It is clarified that, although there seems to be no local minimum in the potential for the Wilson line phases in the pure Yang-Mills case, by including matter fields, we could find a vacuum configuration where tachyonic states disappear.
[ { "created": "Wed, 24 Apr 2024 11:51:53 GMT", "version": "v1" }, { "created": "Fri, 19 Jul 2024 11:44:31 GMT", "version": "v2" } ]
2024-07-22
[ [ "Kojima", "Kentaro", "" ], [ "Okubo", "Yuri", "" ], [ "Takeda", "Carolina Sayuri", "" ] ]
We analyze the vacuum structure of an eight-dimensional non-abelian gauge theory with a compactified four-dimensional torus as the extra dimensions. As a non-trivial background configuration of the gauge field of an $SU(n)$ gauge group, we suppose a magnetic flux in two extra dimensions, and continuous Wilson line phases are also involved. We introduce matter fields and calculate the mass spectrum of low-energy modes appearing in a four-dimensional effective theory in an $SU(3)$ model as an explicit example. As expected, potentially tachyonic states in four-dimensional modes appear from extra-dimensional gauge fields that couple to the flux background since the gauge group is simply connected. The Wilson line phases give a non-vanishing contribution to their masses, and we have a low-energy mass spectrum without tachyonic states, given that these phases take an appropriate value. To verify the validity of the values of the Wilson line phases, we examine the one-loop effective potential for these phases and explicitly show the contribution from each type of field present in our model. It is clarified that, although there seems to be no local minimum in the potential for the Wilson line phases in the pure Yang-Mills case, by including matter fields, we could find a vacuum configuration where tachyonic states disappear.
0909.5128
Sergey Mikhailov
S. V. Mikhailov, N. G. Stefanis
Two-loop contribution to the pion transition form factor vs. experimental data
5 pages, 2 figures, 3 tables. Presented by the first author at 3rd joint International HADRON STRUCTURE'09 Conference at Tatranska Strba, Slovakia, August 30th - September 3rd, 2009. v2 Eqs. (9), (10) corrected; wrong reference tag removed. v3 Fig. 2 and Ref. [13] corrected
null
10.1016/j.nuclphysbps.2009.12.039
RUB-TPII-09/09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present predictions for the pion-photon transition form factor, derived with the help of light-cone sum rules and including the main part of the NNLO radiative corrections. We show that, when the Bakulev-Mikhailov-Stefanis (BMS) pion distribution amplitude is used, the obtained predictions agree well with the CELLO and the CLEO data. We found that no model distribution amplitude can reproduce the observed $Q^2$ growth of the new BaBar data, though the BMS model complies with several BaBar data points.
[ { "created": "Mon, 28 Sep 2009 15:51:44 GMT", "version": "v1" }, { "created": "Tue, 29 Sep 2009 14:05:52 GMT", "version": "v2" }, { "created": "Sat, 12 Dec 2009 08:34:24 GMT", "version": "v3" } ]
2015-05-14
[ [ "Mikhailov", "S. V.", "" ], [ "Stefanis", "N. G.", "" ] ]
We present predictions for the pion-photon transition form factor, derived with the help of light-cone sum rules and including the main part of the NNLO radiative corrections. We show that, when the Bakulev-Mikhailov-Stefanis (BMS) pion distribution amplitude is used, the obtained predictions agree well with the CELLO and the CLEO data. We found that no model distribution amplitude can reproduce the observed $Q^2$ growth of the new BaBar data, though the BMS model complies with several BaBar data points.
1107.2136
William Horowitz
W. A. Horowitz and Miklos Gyulassy
Quenching and Tomography from RHIC to LHC
4 pages, 3 figures. Proceedings for Quark Matter 2011
null
10.1088/0954-3899/38/12/124114
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compare fully perturbative and fully nonperturbative pictures of high-pT energy loss calculations to the first results from LHC. While over-suppressed compared to published ALICE data, parameter-free pQCD predictions based on the WHDG energy loss model constrained to RHIC data simultaneously describe well the preliminary CMS hadron suppression, ATLAS charged hadron v2, and ALICE D meson suppression; we also provide for future reference WHDG predictions for B meson RAA. However, energy loss calculations based on AdS/CFT also qualitatively describe well the RHIC pion and non-photonic electron suppression and LHC charged hadron suppression. We propose the double ratio of charm to bottom quark RAA will qualitatively distinguish between these two energy loss pictures.
[ { "created": "Mon, 11 Jul 2011 20:37:06 GMT", "version": "v1" } ]
2015-05-28
[ [ "Horowitz", "W. A.", "" ], [ "Gyulassy", "Miklos", "" ] ]
We compare fully perturbative and fully nonperturbative pictures of high-pT energy loss calculations to the first results from LHC. While over-suppressed compared to published ALICE data, parameter-free pQCD predictions based on the WHDG energy loss model constrained to RHIC data simultaneously describe well the preliminary CMS hadron suppression, ATLAS charged hadron v2, and ALICE D meson suppression; we also provide for future reference WHDG predictions for B meson RAA. However, energy loss calculations based on AdS/CFT also qualitatively describe well the RHIC pion and non-photonic electron suppression and LHC charged hadron suppression. We propose the double ratio of charm to bottom quark RAA will qualitatively distinguish between these two energy loss pictures.
hep-ph/0311325
Dr. Gavin P. Salam
Marcello Ciafaloni, Dimitri Colferai, Gavin P. Salam, Anna M. Stasto
The gluon splitting function at moderately small x
10 pages, LaTeX, 3 figures
Phys.Lett.B587:87-94,2004
10.1016/j.physletb.2004.02.054
DESY 03-185, DFF 409/11/03, LPTHE-03-34
hep-ph
null
It is widely believed that at small x, the BFKL resummed gluon splitting function should grow as a power of 1/x. But in several recent calculations it has been found to decrease for moderately small-x before eventually rising. We show that this `dip' structure is a rigorous feature of the P_gg splitting function for sufficiently small alpha_s, the minimum occurring formally at ln 1/x of order 1/sqrt(alpha_s). We calculate the properties of the dip, including corrections of relative order sqrt(alpha_s), and discuss how this expansion in powers of sqrt(alpha_s), which is poorly convergent, can be qualitatively matched to the fully resummed result of a recent calculation, for realistic values of alpha_s. Finally, we note that the dip position, as a function of alpha_s, provides a lower bound in x below which the NNLO fixed-order expansion of the splitting function breaksdown and the resummation of small-x terms is mandatory.
[ { "created": "Tue, 25 Nov 2003 14:52:16 GMT", "version": "v1" }, { "created": "Mon, 3 May 2004 06:02:28 GMT", "version": "v2" } ]
2014-11-17
[ [ "Ciafaloni", "Marcello", "" ], [ "Colferai", "Dimitri", "" ], [ "Salam", "Gavin P.", "" ], [ "Stasto", "Anna M.", "" ] ]
It is widely believed that at small x, the BFKL resummed gluon splitting function should grow as a power of 1/x. But in several recent calculations it has been found to decrease for moderately small-x before eventually rising. We show that this `dip' structure is a rigorous feature of the P_gg splitting function for sufficiently small alpha_s, the minimum occurring formally at ln 1/x of order 1/sqrt(alpha_s). We calculate the properties of the dip, including corrections of relative order sqrt(alpha_s), and discuss how this expansion in powers of sqrt(alpha_s), which is poorly convergent, can be qualitatively matched to the fully resummed result of a recent calculation, for realistic values of alpha_s. Finally, we note that the dip position, as a function of alpha_s, provides a lower bound in x below which the NNLO fixed-order expansion of the splitting function breaksdown and the resummation of small-x terms is mandatory.
1311.6366
Vincent Mathieu
Vincent Mathieu
Regge Amplitudes for Two-to-Two Reactions
14 pages, 14 figures, talk given at "From quarks and gluons to hadronic matter: A bridge too far?"[QCD-TNT-III], Trento, Italy, Sept. 2-6, 2013
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a fit based on Regge theory of two-to-two reactions at high energies particulary focused on leading non-strange positive naturality exchanges. Factorization of the residues is assumed between beam and target vertices. This study is a first step toward the analysis of multiple mesons peripherical production.
[ { "created": "Mon, 25 Nov 2013 17:15:49 GMT", "version": "v1" } ]
2013-11-26
[ [ "Mathieu", "Vincent", "" ] ]
We present a fit based on Regge theory of two-to-two reactions at high energies particulary focused on leading non-strange positive naturality exchanges. Factorization of the residues is assumed between beam and target vertices. This study is a first step toward the analysis of multiple mesons peripherical production.
hep-ph/0310305
Juan Antonio Aguilar-Saavedra
J. A. Aguilar-Saavedra, G. C. Branco, F. R. Joaquim
Neutrino Masses, Mixing and New Physics Effects
14 pages, 21 figures. Uses RevTeX4. Added several comments and references. Final version to appear in PRD
Phys.Rev. D69 (2004) 073004
10.1103/PhysRevD.69.073004
null
hep-ph
null
We introduce a parametrization of the effects of radiative corrections from new physics on the charged lepton and neutrino mass matrices, studying how several relevant quantities describing the pattern of neutrino masses and mixing are affected by these corrections. We find that the ratio omega = sin theta / tan theta_atm is remarkably stable, even when relatively large corrections are added to the original mass matrices. It is also found that if the lightest neutrino has a mass around 0.3 eV, the pattern of masses and mixings is considerably more stable under perturbations than for a lighter or heavier spectrum. We explore the consequences of perturbations on some flavor relations given in the literature. In addition, for a quasi-degenerate neutrino spectrum it is shown that: (i) starting from a bi-maximal mixing scenario, the corrections to the mass matrices keep tan theta_atm very close to unity while they can lower tan theta_sol to its measured value; (ii) beginning from a scenario with a vanishing Dirac phase, corrections can induce a Dirac phase large enough to yield CP violation observable in neutrino oscillations.
[ { "created": "Mon, 27 Oct 2003 21:06:25 GMT", "version": "v1" }, { "created": "Tue, 9 Dec 2003 18:04:25 GMT", "version": "v2" } ]
2009-11-10
[ [ "Aguilar-Saavedra", "J. A.", "" ], [ "Branco", "G. C.", "" ], [ "Joaquim", "F. R.", "" ] ]
We introduce a parametrization of the effects of radiative corrections from new physics on the charged lepton and neutrino mass matrices, studying how several relevant quantities describing the pattern of neutrino masses and mixing are affected by these corrections. We find that the ratio omega = sin theta / tan theta_atm is remarkably stable, even when relatively large corrections are added to the original mass matrices. It is also found that if the lightest neutrino has a mass around 0.3 eV, the pattern of masses and mixings is considerably more stable under perturbations than for a lighter or heavier spectrum. We explore the consequences of perturbations on some flavor relations given in the literature. In addition, for a quasi-degenerate neutrino spectrum it is shown that: (i) starting from a bi-maximal mixing scenario, the corrections to the mass matrices keep tan theta_atm very close to unity while they can lower tan theta_sol to its measured value; (ii) beginning from a scenario with a vanishing Dirac phase, corrections can induce a Dirac phase large enough to yield CP violation observable in neutrino oscillations.
1001.3156
Pierpaolo Mastrolia
Pierpaolo Mastrolia
Unitarity-Cuts, Stokes' Theorem and Berry's Phase
presented at RADCOR 2009 - 9th International Symposium on Radiative Corrections, October 25 - 30 2009, Ascona, Switzerland
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two-particle unitarity-cuts of scattering amplitudes can be efficiently computed by applying Stokes' Theorem, in the fashion of the Generalised Cauchy Theorem. Consequently, the Optical Theorem can be related to the Berry Phase, showing how the imaginary part of arbitrary one-loop Feynman amplitudes can be interpreted as the flux of a complex 2-form.
[ { "created": "Mon, 18 Jan 2010 22:18:57 GMT", "version": "v1" } ]
2010-01-20
[ [ "Mastrolia", "Pierpaolo", "" ] ]
Two-particle unitarity-cuts of scattering amplitudes can be efficiently computed by applying Stokes' Theorem, in the fashion of the Generalised Cauchy Theorem. Consequently, the Optical Theorem can be related to the Berry Phase, showing how the imaginary part of arbitrary one-loop Feynman amplitudes can be interpreted as the flux of a complex 2-form.
2201.06471
Kanchan Khemchandani
K. P. Khemchandani, A. Mart\'inez Torres, Sang-Ho Kim, Seung-il Nam, H. Nagahiro, A. Hosaka
The decay of $N^*$(1895) to light hyperon resonances
Hadron 2021 conference proceedings
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
In this talk I review the findings of our recent works where we have studied the decay of $N^*(1895)$ and the implications of such properties on the photoproduction of light hyperons. I discuss that meson-baryon interactions play an essential role in describing the nature of $N^*(1895)$ and report the details of our investigation of its decays to different meson-baryon systems and to final states involving $\Lambda(1405)$ and a proposed $\Sigma(1400)$. We find that the width of $N^*(1895)$ gets important contributions from the decay to light hyperon resonances. Such an information can be used to look for alternative processes to study $N^*(1895)$ in experimental data.
[ { "created": "Mon, 17 Jan 2022 15:31:45 GMT", "version": "v1" } ]
2022-01-19
[ [ "Khemchandani", "K. P.", "" ], [ "Torres", "A. Martínez", "" ], [ "Kim", "Sang-Ho", "" ], [ "Nam", "Seung-il", "" ], [ "Nagahiro", "H.", "" ], [ "Hosaka", "A.", "" ] ]
In this talk I review the findings of our recent works where we have studied the decay of $N^*(1895)$ and the implications of such properties on the photoproduction of light hyperons. I discuss that meson-baryon interactions play an essential role in describing the nature of $N^*(1895)$ and report the details of our investigation of its decays to different meson-baryon systems and to final states involving $\Lambda(1405)$ and a proposed $\Sigma(1400)$. We find that the width of $N^*(1895)$ gets important contributions from the decay to light hyperon resonances. Such an information can be used to look for alternative processes to study $N^*(1895)$ in experimental data.
1706.08679
Premomoy Ghosh
Nachiketa Sarkar, Premomoy Ghosh
Thermalization in small system of hadron gas and high-multiplicity pp events
null
Phys. Rev. C 96, 044901 (2017)
10.1103/PhysRevC.96.044901
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the system-size dependence of Knudsen number, a measure of degree of thermalization, for hadron resonance gas that follows the Lattice-QCD equation of state at zero chemical potential. A comparison between Knudsen numbers for the AuAu collisions at RHIC and the hadron gas of size similar to the size of high-multiplicity pp events at LHC, reassures the applicability of hydrodynamics in interpreting the features of particle production in high-multiplicity pp events.
[ { "created": "Tue, 27 Jun 2017 06:19:38 GMT", "version": "v1" }, { "created": "Fri, 22 Sep 2017 09:15:09 GMT", "version": "v2" } ]
2017-10-11
[ [ "Sarkar", "Nachiketa", "" ], [ "Ghosh", "Premomoy", "" ] ]
We study the system-size dependence of Knudsen number, a measure of degree of thermalization, for hadron resonance gas that follows the Lattice-QCD equation of state at zero chemical potential. A comparison between Knudsen numbers for the AuAu collisions at RHIC and the hadron gas of size similar to the size of high-multiplicity pp events at LHC, reassures the applicability of hydrodynamics in interpreting the features of particle production in high-multiplicity pp events.
hep-ph/9903227
Massimo Pietroni
D. Comelli, D. Grasso, M. Pietroni and A. Riotto
The Sphaleron in a Magnetic Field and Electroweak Baryogenesis
10 pages, 2 figures
Phys.Lett. B458 (1999) 304-309
10.1016/S0370-2693(99)00381-0
INFNFE-01-99, DFPD/99/TH/07, CERN-TH/99-50
hep-ph
null
The presence of a primordial magnetic field in the early universe affects the dynamic of the electroweak phase transition enhancing its strength. This effect may enlarge the window for electroweak baryogenesis in the minimal supersymmetric extension of the standard model or even resurrect the electroweak baryogenesis scenario in the standard model. We compute the sphaleron energy in the background of the magnetic field and show that, due to the sphaleron dipole moment, the barrier between topologically inequivalent vacua is lowered. Therefore, the preservation of the baryon asymmetry calls for a much stronger phase transition than required in the absence of a magnetic field. We show that this effect overwhelms the gain in the phase transition strength, and conclude that magnetic fields do not help electroweak baryogenesis.
[ { "created": "Tue, 2 Mar 1999 15:48:50 GMT", "version": "v1" } ]
2009-10-31
[ [ "Comelli", "D.", "" ], [ "Grasso", "D.", "" ], [ "Pietroni", "M.", "" ], [ "Riotto", "A.", "" ] ]
The presence of a primordial magnetic field in the early universe affects the dynamic of the electroweak phase transition enhancing its strength. This effect may enlarge the window for electroweak baryogenesis in the minimal supersymmetric extension of the standard model or even resurrect the electroweak baryogenesis scenario in the standard model. We compute the sphaleron energy in the background of the magnetic field and show that, due to the sphaleron dipole moment, the barrier between topologically inequivalent vacua is lowered. Therefore, the preservation of the baryon asymmetry calls for a much stronger phase transition than required in the absence of a magnetic field. We show that this effect overwhelms the gain in the phase transition strength, and conclude that magnetic fields do not help electroweak baryogenesis.
hep-ph/0604128
Feng Yuan
Xiangdong Ji, Jian-Wei Qiu, Werner Vogelsang, Feng Yuan
Single-Transverse Spin Asymmetry in Semi-Inclusive Deep Inelastic Scattering
17 pages, 3 figures
Phys.Lett.B638:178-186,2006
10.1016/j.physletb.2006.05.044
BNL-NT-06/15, RBRC-598
hep-ph
null
We study the single-transverse spin asymmetry in semi-inclusive hadron production in deep inelastic scattering. We derive the leading contribution to the asymmetry at moderate transverse momentum $P_{h\perp}$ of the produced hadron in terms of twist-three quark-gluon correlation functions, and compare with the approach based on the factorization at fixed transverse momentum involving the asymmetric transverse-momentum and spin-dependent quark distribution. We verify that the two approaches yield identical results in this regime. By a comparison with our earlier calculations for the single-spin asymmetry in the Drell-Yan process we recover the well-established process-dependence of the time-reversal-odd transverse-momentum-dependent quark distributions that generate single-spin phenomena.
[ { "created": "Fri, 14 Apr 2006 15:23:42 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ji", "Xiangdong", "" ], [ "Qiu", "Jian-Wei", "" ], [ "Vogelsang", "Werner", "" ], [ "Yuan", "Feng", "" ] ]
We study the single-transverse spin asymmetry in semi-inclusive hadron production in deep inelastic scattering. We derive the leading contribution to the asymmetry at moderate transverse momentum $P_{h\perp}$ of the produced hadron in terms of twist-three quark-gluon correlation functions, and compare with the approach based on the factorization at fixed transverse momentum involving the asymmetric transverse-momentum and spin-dependent quark distribution. We verify that the two approaches yield identical results in this regime. By a comparison with our earlier calculations for the single-spin asymmetry in the Drell-Yan process we recover the well-established process-dependence of the time-reversal-odd transverse-momentum-dependent quark distributions that generate single-spin phenomena.
2110.01426
Igor Boyko
I.R.Boyko, V.V.Bytev, A.S.Zhemchugov
Two-photon physics at future electron-positron colliders
null
null
10.1088/1674-1137/ac957c
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Two photon collisions offer a variety of physics studies that can be performed at the future electron-positron colliders. Using the planned CEPC parameters as a benchmark we consider several topics to be studied in the two-photon collisions. With the full integrated luminosity the Higgs boson photoproduction can be reliably observed. A large statistics of various quarkonium states can be collected. The LEP results on the photon structure function and the tau lepton anomalous magnetic moment can be improved by 1-2 orders of magnitude.
[ { "created": "Mon, 4 Oct 2021 13:09:46 GMT", "version": "v1" }, { "created": "Fri, 28 Oct 2022 10:57:46 GMT", "version": "v2" } ]
2022-12-14
[ [ "Boyko", "I. R.", "" ], [ "Bytev", "V. V.", "" ], [ "Zhemchugov", "A. S.", "" ] ]
Two photon collisions offer a variety of physics studies that can be performed at the future electron-positron colliders. Using the planned CEPC parameters as a benchmark we consider several topics to be studied in the two-photon collisions. With the full integrated luminosity the Higgs boson photoproduction can be reliably observed. A large statistics of various quarkonium states can be collected. The LEP results on the photon structure function and the tau lepton anomalous magnetic moment can be improved by 1-2 orders of magnitude.
1410.5234
Kazem Azizi
K. Azizi, N. Er, H. Sundu
Semileptonic $B \rightarrow \bar{D} $ transition in nuclear medium
12 Pages, 3 Figures and 5 Tables
null
10.1103/PhysRevD.91.034026
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the semileptonic tree-level $B \rightarrow \bar{D}$ transition in the framework of QCD sum rules in nuclear medium. In particular, we calculate the in-medium form factors entering the transition matrix elements defining this decay channel. It is found that the interactions of the participating particles with the medium lead to a considerable suppression in the branching ratio compared to the vacuum.
[ { "created": "Mon, 20 Oct 2014 11:45:47 GMT", "version": "v1" }, { "created": "Tue, 3 Feb 2015 09:43:32 GMT", "version": "v2" } ]
2015-06-23
[ [ "Azizi", "K.", "" ], [ "Er", "N.", "" ], [ "Sundu", "H.", "" ] ]
We study the semileptonic tree-level $B \rightarrow \bar{D}$ transition in the framework of QCD sum rules in nuclear medium. In particular, we calculate the in-medium form factors entering the transition matrix elements defining this decay channel. It is found that the interactions of the participating particles with the medium lead to a considerable suppression in the branching ratio compared to the vacuum.
hep-ph/0202108
Akihiro Nakamura
Shigenori Kagiyama, Shunichiro Kumamoto, Akira Minaka, Akihiro Nakamura, Kazunari Ohkura and Shogo Yamaguchi
Compressible bag model and the phase structure
14 pages, 11 figures, LaTeX2e
Eur.Phys.J.C25:453-458,2002
10.1007/s10052-002-1024-9
Kagoshima HE-02-1
hep-ph
null
The phase structure of hadrons and quark-gluon plasma is investigated by two types of equation of hadron state, namely ideal hadron gas model and the compressible bag model. It is pointed out that, while the ideal gas model produces unrealistic extra hadron phase, the compressible bag model gives an expected and reasonable phase diagram even if rich hadron spectrum is taken into account.
[ { "created": "Tue, 12 Feb 2002 12:29:25 GMT", "version": "v1" }, { "created": "Mon, 18 Mar 2002 08:30:39 GMT", "version": "v2" }, { "created": "Mon, 22 Apr 2002 11:23:24 GMT", "version": "v3" }, { "created": "Tue, 18 Jun 2002 02:21:02 GMT", "version": "v4" }, { "c...
2011-09-13
[ [ "Kagiyama", "Shigenori", "" ], [ "Kumamoto", "Shunichiro", "" ], [ "Minaka", "Akira", "" ], [ "Nakamura", "Akihiro", "" ], [ "Ohkura", "Kazunari", "" ], [ "Yamaguchi", "Shogo", "" ] ]
The phase structure of hadrons and quark-gluon plasma is investigated by two types of equation of hadron state, namely ideal hadron gas model and the compressible bag model. It is pointed out that, while the ideal gas model produces unrealistic extra hadron phase, the compressible bag model gives an expected and reasonable phase diagram even if rich hadron spectrum is taken into account.
hep-ph/9602342
Osamu Yasuda 0426-77-1111x3376
Osamu Yasuda
Three flavor neutrino oscillation analysis of the kamiokande multi-gev atmospheric neutrino data
LaTeX, 13 pages + 3 PostScript figures
null
null
TMUP-HEL-9603
hep-ph
null
Using the published Kamiokande data of the multi-GeV atmospheric neutrinos, we have searched the optimum set of the neutrino oscillation parameters among three flavors. It is found that $\chi^2$ is minimized for ($\Delta m_{21}^2$, $\Delta m_{31}^2$) = (3.8$\times 10^{-2}~$eV$^2$, 1.4$\times 10^{-2}~$eV$^2$), ($\theta_{12}$, $\theta_{13}$, $\theta_{23}$) = ($19^\circ$,$43^\circ$,$41^\circ$) with $\chi_{\rm min}$ = 3.2 (42\%CL). The sets of parameters ($\Delta m_{21}^2$, $\Delta m_{31}^2$) = (${\cal O}$($10^{-11}$eV$^2$) or ${\cal O}$($10^{-5}$eV$^2$), ${\cal O}$($10^{-2}$eV$^2$)) which are suggested by the two flavor analysis fall within 0.7$\sigma$.
[ { "created": "Tue, 20 Feb 1996 01:46:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Yasuda", "Osamu", "" ] ]
Using the published Kamiokande data of the multi-GeV atmospheric neutrinos, we have searched the optimum set of the neutrino oscillation parameters among three flavors. It is found that $\chi^2$ is minimized for ($\Delta m_{21}^2$, $\Delta m_{31}^2$) = (3.8$\times 10^{-2}~$eV$^2$, 1.4$\times 10^{-2}~$eV$^2$), ($\theta_{12}$, $\theta_{13}$, $\theta_{23}$) = ($19^\circ$,$43^\circ$,$41^\circ$) with $\chi_{\rm min}$ = 3.2 (42\%CL). The sets of parameters ($\Delta m_{21}^2$, $\Delta m_{31}^2$) = (${\cal O}$($10^{-11}$eV$^2$) or ${\cal O}$($10^{-5}$eV$^2$), ${\cal O}$($10^{-2}$eV$^2$)) which are suggested by the two flavor analysis fall within 0.7$\sigma$.
hep-ph/9909341
Walter Grimus
W. Grimus, S. Mohanty, P. Stockinger
Field-Theoretical Treatment of Neutrino Oscillations: The Strength of the Canonical Oscillation Formula
15 pages, Revtex, Contribution to "Neutrino Mixing", Meeting in Honour of Samoil Bilenky's 70th Birthday, Torino, March 25-27, 1999
null
null
UWThPh-1999-54, PRL-TH-1999
hep-ph
null
We discuss conceptual aspects of neutrino oscillations with the main emphasis on the field-theoretical approach. This approach includes the neutrino source and detector processes and allows to obtain the neutrino transition or survival probabilities as cross sections derived from the Feynman diagram of the combined source - detection process. In this context, the neutrinos which are supposed to oscillate appear as propagators of the neutrino mass eigenfields, connecting the source and detection processes. We consider also the question why the canonical neutrino oscillation formula is so robust against corrections and discuss the nature of the oscillating neutrino state emerging in the field-theoretical approach.
[ { "created": "Mon, 13 Sep 1999 09:43:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grimus", "W.", "" ], [ "Mohanty", "S.", "" ], [ "Stockinger", "P.", "" ] ]
We discuss conceptual aspects of neutrino oscillations with the main emphasis on the field-theoretical approach. This approach includes the neutrino source and detector processes and allows to obtain the neutrino transition or survival probabilities as cross sections derived from the Feynman diagram of the combined source - detection process. In this context, the neutrinos which are supposed to oscillate appear as propagators of the neutrino mass eigenfields, connecting the source and detection processes. We consider also the question why the canonical neutrino oscillation formula is so robust against corrections and discuss the nature of the oscillating neutrino state emerging in the field-theoretical approach.
hep-ph/9411366
null
Marion Flanz, Emmanuel A. Paschos and Utpal Sarkar
Baryogenesis from a Lepton Asymmetric Universe
12 pages (Latex file with one attached postscript figure)
Phys.Lett.B345:248-252,1995; ERRATUM-ibid.B382:447,1996
10.1016/0370-2693(94)01555-Q
DO-TH 94/15
hep-ph
null
We demonstrate that $CP-$violation in the Majorana mass matrices of the heavy neutrinos can generate a $CP-$asymmetric universe. The subsequent decay of the Majorana particles generates a lepton number asymmetry. During the electroweak phase transition the lepton asymmetry is converted into a baryon asymmetry, which survives down to this time.
[ { "created": "Wed, 23 Nov 1994 09:03:05 GMT", "version": "v1" } ]
2010-11-01
[ [ "Flanz", "Marion", "" ], [ "Paschos", "Emmanuel A.", "" ], [ "Sarkar", "Utpal", "" ] ]
We demonstrate that $CP-$violation in the Majorana mass matrices of the heavy neutrinos can generate a $CP-$asymmetric universe. The subsequent decay of the Majorana particles generates a lepton number asymmetry. During the electroweak phase transition the lepton asymmetry is converted into a baryon asymmetry, which survives down to this time.
2310.04123
Eduard Paryev Ph.D
E. Ya. Paryev
Probing the hidden-bottom pentaquark resonances in photonuclear bottomonium production near threshold: differential observables
33 pages, 13 figures. arXiv admin note: text overlap with arXiv:2211.16037, arXiv:2304.03978; references and some additional comments are added
Nucl.Phys.A 1042(2024)122792
10.1016/j.nuclphysa.2023.122792
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We study the near-threshold $\Upsilon(1S)$ meson photoproduction from protons and nuclei by considering incoherent direct non-resonant (${\gamma}p \to {\Upsilon(1S)}p$, ${\gamma}n \to {\Upsilon(1S)}n$) and two-step resonant (${\gamma}p \to P^+_{bi} \to {\Upsilon(1S)}p$, ${\gamma}n \to P^0_{bi} \to {\Upsilon(1S)}n$, $i=1$, 2, 3; $P^{+,0}_{b1}=P^{+,0}_{b}(11080)$, $P^{+,0}_{b2}=P^{+,0}_{b}(11125)$, $P^{+,0}_{b3}=P^{+,0}_{b}(11130)$) bottomonium production processes with the main goal of clarifying the possibility to observe the non-strange hidden-bottom pentaquark states $P^{+,0}_{bi}$ in this production via differential observables. We calculate the absolute excitation functions, energy and momentum distributions for the non-resonant, resonant and for the combined (non-resonant plus resonant) production of $\Upsilon(1S)$ mesons on protons, on carbon and tungsten target nuclei at near-threshold incident photon beam energies by assuming the spin-parity assignments of the hypothetical hidden-bottom resonances $P^{+,0}_{b}(11080)$, $P^{+,0}_{b}(11125)$ and $P^{+,0}_{b}(11130)$ as $J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within four different realistic choices for the branching ratios of their decays to the ${\Upsilon}(1S)p$ and ${\Upsilon}(1S)n$ modes (0.125, 0.25, 0.5 and 1\%) as well as for two options for the background contribution. We demonstrate that the measurements of these combined observables on proton and nuclear targets in the near-threshold energy region in future experiments at the planned high-luminosity electron-ion colliders EIC and EicC in the US and China should provide evidence for the existence of the above hidden-bottom pentaquark resonances as well as clarify their decay rates.
[ { "created": "Fri, 6 Oct 2023 09:42:56 GMT", "version": "v1" }, { "created": "Thu, 23 Nov 2023 07:47:03 GMT", "version": "v2" } ]
2023-11-27
[ [ "Paryev", "E. Ya.", "" ] ]
We study the near-threshold $\Upsilon(1S)$ meson photoproduction from protons and nuclei by considering incoherent direct non-resonant (${\gamma}p \to {\Upsilon(1S)}p$, ${\gamma}n \to {\Upsilon(1S)}n$) and two-step resonant (${\gamma}p \to P^+_{bi} \to {\Upsilon(1S)}p$, ${\gamma}n \to P^0_{bi} \to {\Upsilon(1S)}n$, $i=1$, 2, 3; $P^{+,0}_{b1}=P^{+,0}_{b}(11080)$, $P^{+,0}_{b2}=P^{+,0}_{b}(11125)$, $P^{+,0}_{b3}=P^{+,0}_{b}(11130)$) bottomonium production processes with the main goal of clarifying the possibility to observe the non-strange hidden-bottom pentaquark states $P^{+,0}_{bi}$ in this production via differential observables. We calculate the absolute excitation functions, energy and momentum distributions for the non-resonant, resonant and for the combined (non-resonant plus resonant) production of $\Upsilon(1S)$ mesons on protons, on carbon and tungsten target nuclei at near-threshold incident photon beam energies by assuming the spin-parity assignments of the hypothetical hidden-bottom resonances $P^{+,0}_{b}(11080)$, $P^{+,0}_{b}(11125)$ and $P^{+,0}_{b}(11130)$ as $J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within four different realistic choices for the branching ratios of their decays to the ${\Upsilon}(1S)p$ and ${\Upsilon}(1S)n$ modes (0.125, 0.25, 0.5 and 1\%) as well as for two options for the background contribution. We demonstrate that the measurements of these combined observables on proton and nuclear targets in the near-threshold energy region in future experiments at the planned high-luminosity electron-ion colliders EIC and EicC in the US and China should provide evidence for the existence of the above hidden-bottom pentaquark resonances as well as clarify their decay rates.
1710.02204
Norimi Yokozaki
Keisuke Harigaya, Tsutomu T. Yanagida, Norimi Yokozaki
Axion induced SUSY breaking and focus point gaugino mediation
21 pages, 2 figures; version to be published
null
10.1016/j.physletb.2022.137386
IPMU17-0134, TU-1047
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a scenario where the supersymmetry breaking and its mediation, and the cancellation of the theta parameter of SU(3)c are all caused by a single chiral multiplet. The string axion multiplet is a natural candidate of such a single superfield. We show that the scenario provides a convincing basis of focus point gaugino mediation, where the electroweak scale is explained with a moderate tuning among the parameters of the theory.
[ { "created": "Thu, 5 Oct 2017 20:20:54 GMT", "version": "v1" }, { "created": "Mon, 13 Jun 2022 05:59:00 GMT", "version": "v2" }, { "created": "Fri, 19 Aug 2022 08:21:42 GMT", "version": "v3" } ]
2022-08-30
[ [ "Harigaya", "Keisuke", "" ], [ "Yanagida", "Tsutomu T.", "" ], [ "Yokozaki", "Norimi", "" ] ]
We consider a scenario where the supersymmetry breaking and its mediation, and the cancellation of the theta parameter of SU(3)c are all caused by a single chiral multiplet. The string axion multiplet is a natural candidate of such a single superfield. We show that the scenario provides a convincing basis of focus point gaugino mediation, where the electroweak scale is explained with a moderate tuning among the parameters of the theory.
2312.14004
Gino Isidori
Riccardo Barbieri, Gino Isidori
Minimal flavour deconstruction
20 pages, 4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct two concrete examples of flavour non-universal gauge theories which, after the inclusion of all $d\leq 4$ gauge invariant operators, allow to describe the observed pattern of flavour in the charged fermion sector without any small Yukawa coupling ($y \gtrsim 0.1$). Guided by the criterium of minimality, we assume that flavour non universality is confined to the Abelian sector of the gauge group: the universal hypercharge emerges after a sequence of symmetry-breaking steps characterised by two high mass scales, $\Lambda_{[23]} < \Lambda_{[12]}$, where the second and the first fermion generations get their mass respectively. At least in one of the two models the smaller of these scales can be in the 10 TeV range, consistently with current bounds from flavour observables. Both models are extended to include as well neutrino masses and mixings.
[ { "created": "Thu, 21 Dec 2023 16:36:00 GMT", "version": "v1" } ]
2023-12-22
[ [ "Barbieri", "Riccardo", "" ], [ "Isidori", "Gino", "" ] ]
We construct two concrete examples of flavour non-universal gauge theories which, after the inclusion of all $d\leq 4$ gauge invariant operators, allow to describe the observed pattern of flavour in the charged fermion sector without any small Yukawa coupling ($y \gtrsim 0.1$). Guided by the criterium of minimality, we assume that flavour non universality is confined to the Abelian sector of the gauge group: the universal hypercharge emerges after a sequence of symmetry-breaking steps characterised by two high mass scales, $\Lambda_{[23]} < \Lambda_{[12]}$, where the second and the first fermion generations get their mass respectively. At least in one of the two models the smaller of these scales can be in the 10 TeV range, consistently with current bounds from flavour observables. Both models are extended to include as well neutrino masses and mixings.
1512.04933
Alessandro Strumia
Roberto Franceschini, Gian F. Giudice, Jernej F. Kamenik, Matthew McCullough, Alex Pomarol, Riccardo Rattazzi, Michele Redi, Francesco Riva, Alessandro Strumia and Riccardo Torre
What is the gamma gamma resonance at 750 GeV?
v2: 45 pages, 12 figures, final. Factor of 2 changed in table 1, 4th row
null
10.1007/JHEP03(2016)144
CERN-PH-TH/2015-302, IFUP-TH/2015
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Run 2 LHC data show hints of a new resonance in the diphoton distribution at an invariant mass of 750 GeV. We analyse the data in terms of a new boson, extracting information on its properties and exploring theoretical interpretations. Scenarios covered include a narrow resonance and, as preliminary indications suggest, a wider resonance. If the width indications persist, the new particle is likely to belong to a strongly-interacting sector. We also show how compatibility between Run 1 and Run 2 data is improved by postulating the existence of an additional heavy particle, whose decays are possibly related to dark matter.
[ { "created": "Tue, 15 Dec 2015 20:53:14 GMT", "version": "v1" }, { "created": "Fri, 8 Jan 2016 18:39:42 GMT", "version": "v2" }, { "created": "Fri, 19 Feb 2016 11:22:23 GMT", "version": "v3" } ]
2016-04-20
[ [ "Franceschini", "Roberto", "" ], [ "Giudice", "Gian F.", "" ], [ "Kamenik", "Jernej F.", "" ], [ "McCullough", "Matthew", "" ], [ "Pomarol", "Alex", "" ], [ "Rattazzi", "Riccardo", "" ], [ "Redi", "Michele", ...
Run 2 LHC data show hints of a new resonance in the diphoton distribution at an invariant mass of 750 GeV. We analyse the data in terms of a new boson, extracting information on its properties and exploring theoretical interpretations. Scenarios covered include a narrow resonance and, as preliminary indications suggest, a wider resonance. If the width indications persist, the new particle is likely to belong to a strongly-interacting sector. We also show how compatibility between Run 1 and Run 2 data is improved by postulating the existence of an additional heavy particle, whose decays are possibly related to dark matter.
hep-ph/0412246
Evgenij Martynov
E. Martynov, J.R. Cudell, A. Lengyel
Direct extraction of hadronic form factors from elastic-scattering data
4 pages, 5 figures, talk given at Diffraction 2004, Cala Gonone, Sardinia, Italy, 18-23 September 2004
null
10.1016/j.nuclphysbps.2005.02.091
null
hep-ph
null
Non-forward elastic hadron-scattering data are collected and analysed within the Regge approach. Through an analysis of the data in small bins in $t$, we have directly extracted the pomeron trajectory and the hadronic form factors (or reggeon couplings). We found higher values than usually used for the intercept and for the slope of the soft pomeron trajectory. The presence of zeros in $t$ for the effective hadronic form factors is emphasised.
[ { "created": "Fri, 17 Dec 2004 09:36:54 GMT", "version": "v1" } ]
2009-11-10
[ [ "Martynov", "E.", "" ], [ "Cudell", "J. R.", "" ], [ "Lengyel", "A.", "" ] ]
Non-forward elastic hadron-scattering data are collected and analysed within the Regge approach. Through an analysis of the data in small bins in $t$, we have directly extracted the pomeron trajectory and the hadronic form factors (or reggeon couplings). We found higher values than usually used for the intercept and for the slope of the soft pomeron trajectory. The presence of zeros in $t$ for the effective hadronic form factors is emphasised.
hep-ph/9406299
Thomas Teubner
K.G.Chetyrkin and J.H. K\"uhn
Quartic Mass Corrections to $R_{had}$
17 pages, LaTex (uses epsf.sty, figures appended as uuencoded ps- and eps-files). A complete postscript file, including figures, is available via anonymous ftp at ttpux2.physik.uni-karlsruhe.de (129.13.102.139) as /pub/ttp94-08/ttp94-08.ps, Local preprint# TTP94-08
Nucl.Phys.B432:337-350,1994
10.1016/0550-3213(94)90605-X
null
hep-ph
null
The influence of nonvanishing quark masses on the total cross section in electron positron collisions and on the $Z$ decay rate is calculated. The corrections are expanded in $m^2/s$ and $\as$. Methods similar to those applied for the quadratic mass terms allow to derive the corrections of order $\as m^4/s^2$ and $\as^2m^4/s^2$. Coefficients which depend logarithmically on $m^2/s$ and which cannot be absorbed in a running quark mass arise in order $\as^2$. The implications of these results on electron positron annihilation cross sections at LEP and at lower energies in particular between the charm and the bottom threshold and for energies several GeV above the $b\bar b$ threshold are discussed.
[ { "created": "Mon, 13 Jun 1994 17:51:41 GMT", "version": "v1" } ]
2011-01-25
[ [ "Chetyrkin", "K. G.", "" ], [ "Kühn", "J. H.", "" ] ]
The influence of nonvanishing quark masses on the total cross section in electron positron collisions and on the $Z$ decay rate is calculated. The corrections are expanded in $m^2/s$ and $\as$. Methods similar to those applied for the quadratic mass terms allow to derive the corrections of order $\as m^4/s^2$ and $\as^2m^4/s^2$. Coefficients which depend logarithmically on $m^2/s$ and which cannot be absorbed in a running quark mass arise in order $\as^2$. The implications of these results on electron positron annihilation cross sections at LEP and at lower energies in particular between the charm and the bottom threshold and for energies several GeV above the $b\bar b$ threshold are discussed.
2105.05860
Jong-Hyun Yoon
Oleg Lebedev, Jong-Hyun Yoon
Challenges for Inflaton Dark Matter
16 pages, 4 figures
null
10.1016/j.physletb.2021.136614
null
hep-ph astro-ph.CO astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
We examine an intriguing possibility that a single field is responsible for both inflation and dark matter, focussing on the minimal set-up where inflation is driven by a scalar coupling to curvature. We study in detail the reheating process in this framework, which amounts mainly to particle production in a quartic potential, and distinguish thermal and non-thermal dark matter options. In the non-thermal case, the reheating is impeded by backreaction and rescattering, making this possibility unrealistic. On the other hand, thermalized dark matter is viable, yet the unitarity bound forces the inflaton mass into a narrow window close to half the Higgs mass.
[ { "created": "Wed, 12 May 2021 18:00:02 GMT", "version": "v1" }, { "created": "Fri, 13 Aug 2021 07:27:10 GMT", "version": "v2" } ]
2021-09-08
[ [ "Lebedev", "Oleg", "" ], [ "Yoon", "Jong-Hyun", "" ] ]
We examine an intriguing possibility that a single field is responsible for both inflation and dark matter, focussing on the minimal set-up where inflation is driven by a scalar coupling to curvature. We study in detail the reheating process in this framework, which amounts mainly to particle production in a quartic potential, and distinguish thermal and non-thermal dark matter options. In the non-thermal case, the reheating is impeded by backreaction and rescattering, making this possibility unrealistic. On the other hand, thermalized dark matter is viable, yet the unitarity bound forces the inflaton mass into a narrow window close to half the Higgs mass.
hep-ph/0203106
Jack Laiho
Jack Laiho, Amarjit Soni
On lattice extraction of K --> pi pi amplitudes to O(p^4) in Chiral Perturbation Theory
20 pages, 1 figure. This is the final published version, where some minor corrections have been made
Phys.Rev. D65 (2002) 114020
10.1103/PhysRevD.65.114020
null
hep-ph hep-lat
null
We show that lattice calculation of K --> pi pi and $epe$ amplitudes for (8,1) and (27,1) operators to O(p^4) in chiral perturbation theory is feasible when one uses K --> pi pi computations at the two unphysical kinematics allowed by the Maiani-Testa theorem, along with the usual (computable) two and three point functions, namely K --> 0, K --> pi (with momentum) and K - bar{K}. Explicit expressions for the finite logarithms emerging from our O(p^4) analysis to the above amplitudes are also given.
[ { "created": "Tue, 12 Mar 2002 02:46:38 GMT", "version": "v1" }, { "created": "Wed, 27 Mar 2002 20:58:23 GMT", "version": "v2" }, { "created": "Fri, 26 Jul 2002 18:04:52 GMT", "version": "v3" } ]
2009-11-07
[ [ "Laiho", "Jack", "" ], [ "Soni", "Amarjit", "" ] ]
We show that lattice calculation of K --> pi pi and $epe$ amplitudes for (8,1) and (27,1) operators to O(p^4) in chiral perturbation theory is feasible when one uses K --> pi pi computations at the two unphysical kinematics allowed by the Maiani-Testa theorem, along with the usual (computable) two and three point functions, namely K --> 0, K --> pi (with momentum) and K - bar{K}. Explicit expressions for the finite logarithms emerging from our O(p^4) analysis to the above amplitudes are also given.
0810.0934
Seung Lee
Leandro G. Almeida, Seung J. Lee, Gilad Perez, Ilmo Sung, Joseph Virzi
Top Jets at the LHC
46 pages, 23 figures
Phys.Rev.D79:074012,2009
10.1103/PhysRevD.79.074012
YITP-SB-08-37; WIS/17/08-SEPT-DPP
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the reconstruction of high p_T hadronically-decaying top quarks at the LHC. The main challenge in identifying energetic top quarks is that the decay products become increasingly collimated. This reduces the efficacy of conventional methods that exploit the topology of the top decay chain. We focus on the cases where the decay products of the top quark are reconstructed as a single jet, a "top-jet". The most basic "top-tag" method based on jet mass measurement is considered in detail. To analyze the top-tagging method, theoretical and experimental aspects of the QCD jet background are examined. Based on QCD factorization, we derive a simple analytic approximation for the shape of the QCD jet mass spectrum. We observe a good agreement with the Monte Carlo simulation. We consider high-p_T t\bar{t} production in the Standard Model as an example, and show that our theoretical QCD jet mass distributions can efficiently characterize the background via sideband analyses. We show that with 25 fb^{-1} of data, our approach allows us to resolve top-jets with p_T $\ge$ 1 TeV from the QCD background, and about 1.5 TeV top-jets with 100 fb^{-1}, without relying on b-tagging. To further improve the significance we consider jet shapes (analyzed in 0807.0234 [hep-ph]), which resolve the substructure of energy flow inside cone jets. A method of measuring top quark polarization by using the b-quark p_T is also presented. The main advantages of our approach are: (i) the mass distributions are driven by first principle calculations, instead of relying solely on Monte Carlo simulation; (ii) for high p_T jets (p_T $\ge$1 TeV), IR-safe jet shape variables are robust against detector resolution effects. Our analysis is applicable to other boosted massive particles such as the electroweak gauge bosons and the Higgs.
[ { "created": "Mon, 6 Oct 2008 19:56:57 GMT", "version": "v1" } ]
2009-06-11
[ [ "Almeida", "Leandro G.", "" ], [ "Lee", "Seung J.", "" ], [ "Perez", "Gilad", "" ], [ "Sung", "Ilmo", "" ], [ "Virzi", "Joseph", "" ] ]
We study the reconstruction of high p_T hadronically-decaying top quarks at the LHC. The main challenge in identifying energetic top quarks is that the decay products become increasingly collimated. This reduces the efficacy of conventional methods that exploit the topology of the top decay chain. We focus on the cases where the decay products of the top quark are reconstructed as a single jet, a "top-jet". The most basic "top-tag" method based on jet mass measurement is considered in detail. To analyze the top-tagging method, theoretical and experimental aspects of the QCD jet background are examined. Based on QCD factorization, we derive a simple analytic approximation for the shape of the QCD jet mass spectrum. We observe a good agreement with the Monte Carlo simulation. We consider high-p_T t\bar{t} production in the Standard Model as an example, and show that our theoretical QCD jet mass distributions can efficiently characterize the background via sideband analyses. We show that with 25 fb^{-1} of data, our approach allows us to resolve top-jets with p_T $\ge$ 1 TeV from the QCD background, and about 1.5 TeV top-jets with 100 fb^{-1}, without relying on b-tagging. To further improve the significance we consider jet shapes (analyzed in 0807.0234 [hep-ph]), which resolve the substructure of energy flow inside cone jets. A method of measuring top quark polarization by using the b-quark p_T is also presented. The main advantages of our approach are: (i) the mass distributions are driven by first principle calculations, instead of relying solely on Monte Carlo simulation; (ii) for high p_T jets (p_T $\ge$1 TeV), IR-safe jet shape variables are robust against detector resolution effects. Our analysis is applicable to other boosted massive particles such as the electroweak gauge bosons and the Higgs.
hep-ph/9711370
Mcneil James A.
A. S. Johnson and J. A. McNeil (Colorado School of Mines), and J. R. Shepard (University of Colorado)
Renormalization Group Flow Equations for the Sigma Model
22 pages, 4 figures
Phys.Rev.D58:014001,1998
10.1103/PhysRevD.58.014001
CU-NPL-1153
hep-ph
null
We present a nonperturbative renormalization group solution of the Gell-Mann--Levy $\sigma$-model which was originally proposed as a phenomenological description of the dynamics of nucleons and mesons. In our version of the model the fermions are interpreted as quarks which interact via the $\sigma$ and $\pi$ mesons. We derive and numerically solve renormalization group (RG) flow equations to leading order in a derivative expansion to study the behavior of the model as it evolves from high to low momentum scales. We develop an expansion in chiral-symmetry-breaking which enables us to track this symmetry breaking with the evolution of the scale. We use infrared observables to constrain the phenomenology allowing predictions of other quantities such as $\pi-\pi$ scattering lengths. The results show improvement over the tree level calculation and are consistent with experiment and the results of alternate theoretical approaches such as chiral perturbation theory and lattice gauge theory.
[ { "created": "Tue, 18 Nov 1997 16:30:33 GMT", "version": "v1" } ]
2011-07-19
[ [ "Johnson", "A. S.", "", "Colorado School of Mines" ], [ "McNeil", "J. A.", "", "Colorado School of Mines" ], [ "Shepard", "J. R.", "", "University of Colorado" ] ]
We present a nonperturbative renormalization group solution of the Gell-Mann--Levy $\sigma$-model which was originally proposed as a phenomenological description of the dynamics of nucleons and mesons. In our version of the model the fermions are interpreted as quarks which interact via the $\sigma$ and $\pi$ mesons. We derive and numerically solve renormalization group (RG) flow equations to leading order in a derivative expansion to study the behavior of the model as it evolves from high to low momentum scales. We develop an expansion in chiral-symmetry-breaking which enables us to track this symmetry breaking with the evolution of the scale. We use infrared observables to constrain the phenomenology allowing predictions of other quantities such as $\pi-\pi$ scattering lengths. The results show improvement over the tree level calculation and are consistent with experiment and the results of alternate theoretical approaches such as chiral perturbation theory and lattice gauge theory.
2107.06482
Wei-Jie Fu
Yang-yang Tan, Yong-rui Chen, Wei-jie Fu
Real-time dynamics of the $O(4)$ scalar theory within the fRG approach
25 pages, 14 figures; v3: minor revision, discussions updated and reference added
SciPost Phys. 12, 026 (2022)
10.21468/SciPostPhys.12.1.026
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
In this paper, the real-time dynamics of the $O(4)$ scalar theory is studied within the functional renormalization group formulated on the Schwinger-Keldysh closed time path. The flow equations for the effective action and its $n$-point correlation functions are derived in terms of the "classical" and "quantum" fields, and a concise diagrammatic representation is presented. An analytic expression for the flow of the four-point vertex is obtained. Spectral functions with different values of temperature and momentum are obtained. Moreover, we calculate the dynamical critical exponent for the phase transition near the critical temperature in the $O(4)$ scalar theory in $3+1$ dimensions, and the value is found to be $z\simeq 2.023$.
[ { "created": "Wed, 14 Jul 2021 04:46:05 GMT", "version": "v1" }, { "created": "Sun, 3 Oct 2021 03:29:01 GMT", "version": "v2" }, { "created": "Tue, 19 Oct 2021 13:49:34 GMT", "version": "v3" } ]
2022-01-19
[ [ "Tan", "Yang-yang", "" ], [ "Chen", "Yong-rui", "" ], [ "Fu", "Wei-jie", "" ] ]
In this paper, the real-time dynamics of the $O(4)$ scalar theory is studied within the functional renormalization group formulated on the Schwinger-Keldysh closed time path. The flow equations for the effective action and its $n$-point correlation functions are derived in terms of the "classical" and "quantum" fields, and a concise diagrammatic representation is presented. An analytic expression for the flow of the four-point vertex is obtained. Spectral functions with different values of temperature and momentum are obtained. Moreover, we calculate the dynamical critical exponent for the phase transition near the critical temperature in the $O(4)$ scalar theory in $3+1$ dimensions, and the value is found to be $z\simeq 2.023$.
hep-ph/9607350
Nir Polonsky
Nir Polonsky
The neutrino mass and other possible signals of lepton-number violation in supersymmetric theories
Typos corrected + minor changes
Nucl.Phys.Proc.Suppl. 52A (1997) 97-99
10.1016/S0920-5632(96)00542-7
LMU-TPW-96-16
hep-ph
null
We review a recently proposed framework in which the neutrino mass is a signal of supersymmetry breaking and is suppressed dynamically. In addition, we briefly comment on some possible consequences of general lepton-number violation in supersymmetric theories, e.g., dijet and multijet signals and $jj \rightarrow ll\gamma\gamma$.
[ { "created": "Wed, 17 Jul 1996 21:27:27 GMT", "version": "v1" }, { "created": "Fri, 19 Jul 1996 19:55:48 GMT", "version": "v2" } ]
2009-10-28
[ [ "Polonsky", "Nir", "" ] ]
We review a recently proposed framework in which the neutrino mass is a signal of supersymmetry breaking and is suppressed dynamically. In addition, we briefly comment on some possible consequences of general lepton-number violation in supersymmetric theories, e.g., dijet and multijet signals and $jj \rightarrow ll\gamma\gamma$.
hep-ph/0612016
Devin Walker
Vernon Barger, Tao Han and Devin G. E. Walker
Top Quark Pairs at High Invariant Mass - A Model-Independent Discriminator of New Physics at the LHC
5 pages, 4 figures; version to appear in PRL
Phys.Rev.Lett.100:031801,2008
10.1103/PhysRevLett.100.031801
MADPH-06-1475
hep-ph hep-ex
null
We study top quark pair production to probe new physics at the LHC. We propose reconstruction methods for $t\bar{t}$ semileptonic events and use them to reconstruct the $t\bar{t}$ invariant mass. The angular distribution of top quarks in their c.m. frame can determine the spin and production subprocess for each new physics resonance. Forward-backward asymmetry and CP-odd variables can be constructed to further delineate the nature of new physics. We parametrize the new resonances with a few generic parameters and show high invariant mass top pair production may provide an early indicator for new physics beyond the Standard Model.
[ { "created": "Sat, 2 Dec 2006 02:20:02 GMT", "version": "v1" }, { "created": "Mon, 4 Dec 2006 22:10:15 GMT", "version": "v2" }, { "created": "Wed, 12 Dec 2007 06:49:43 GMT", "version": "v3" }, { "created": "Wed, 12 Dec 2007 22:57:14 GMT", "version": "v4" } ]
2008-11-26
[ [ "Barger", "Vernon", "" ], [ "Han", "Tao", "" ], [ "Walker", "Devin G. E.", "" ] ]
We study top quark pair production to probe new physics at the LHC. We propose reconstruction methods for $t\bar{t}$ semileptonic events and use them to reconstruct the $t\bar{t}$ invariant mass. The angular distribution of top quarks in their c.m. frame can determine the spin and production subprocess for each new physics resonance. Forward-backward asymmetry and CP-odd variables can be constructed to further delineate the nature of new physics. We parametrize the new resonances with a few generic parameters and show high invariant mass top pair production may provide an early indicator for new physics beyond the Standard Model.
2210.01386
Young Ju Ko
Young Ju Ko and Hyun Su Lee
Sensitivities for coherent elastic scattering of solar and supernova neutrinos with future NaI(Tl) dark matter search detectors of COSINE-200/1T
null
Astropart. Phys. 153 (2023) 102890
10.1016/j.astropartphys.2023.102890
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We investigate the prospects for measuring the coherent elastic neutrino-nucleus scattering of solar and supernova neutrinos in future NaI(Tl) dark matter detection experiments. Considering the reduced background and improved light yield of the recently developed NaI(Tl) crystals, more than 3$\sigma$ observation sensitivities of the supernova neutrino within the Milky Way are demonstrated. In the case of the solar neutrino, approximately 3 observations are marginal with a 1 ton NaI(Tl) experiment assuming an order of magnitude reduced background, five photoelectron thresholds, and 5-year data exposure.
[ { "created": "Tue, 4 Oct 2022 04:58:25 GMT", "version": "v1" }, { "created": "Mon, 28 Aug 2023 00:32:31 GMT", "version": "v2" } ]
2023-08-29
[ [ "Ko", "Young Ju", "" ], [ "Lee", "Hyun Su", "" ] ]
We investigate the prospects for measuring the coherent elastic neutrino-nucleus scattering of solar and supernova neutrinos in future NaI(Tl) dark matter detection experiments. Considering the reduced background and improved light yield of the recently developed NaI(Tl) crystals, more than 3$\sigma$ observation sensitivities of the supernova neutrino within the Milky Way are demonstrated. In the case of the solar neutrino, approximately 3 observations are marginal with a 1 ton NaI(Tl) experiment assuming an order of magnitude reduced background, five photoelectron thresholds, and 5-year data exposure.
hep-ph/0307373
Masahide Yamaguchi
Masahide Yamaguchi and Jun'ichi Yokoyama
Chaotic hybrid new inflation in supergravity with a running spectral index
15 pages, to appear in Phys. Rev. D
Phys.Rev. D68 (2003) 123520
10.1103/PhysRevD.68.123520
BROWN-HET-1371, OU-TAP-216
hep-ph astro-ph
null
We propose an inflation model in supergravity, in which chaotic and hybrid inflation occurs successively, followed by new inflation. During hybrid inflation, adiabatic fluctuations with a running spectral index with $\ns >1$ on a large scale and $\ns <1$ on a smaller scale are generated, as favored by recent results of the first year Wilkinson Microwave Anisotropy Probe. The initial condition of new inflation is also set dynamically during hybrid inflation, and its duration and the amplitude of density fluctuations take appropriate values to help early star formation to realize early reionization.
[ { "created": "Wed, 30 Jul 2003 18:30:28 GMT", "version": "v1" }, { "created": "Fri, 7 Nov 2003 18:24:00 GMT", "version": "v2" } ]
2009-11-10
[ [ "Yamaguchi", "Masahide", "" ], [ "Yokoyama", "Jun'ichi", "" ] ]
We propose an inflation model in supergravity, in which chaotic and hybrid inflation occurs successively, followed by new inflation. During hybrid inflation, adiabatic fluctuations with a running spectral index with $\ns >1$ on a large scale and $\ns <1$ on a smaller scale are generated, as favored by recent results of the first year Wilkinson Microwave Anisotropy Probe. The initial condition of new inflation is also set dynamically during hybrid inflation, and its duration and the amplitude of density fluctuations take appropriate values to help early star formation to realize early reionization.
1302.5737
Ping Wang
W. Xie, L. Q. Mo, P. Wang and Stephen R. Cotanch
Coulomb gauge model for hidden charm tetraquarks
13 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spectrum of tetraquark states with hidden charm is studied within an effective QCD Coulomb gauge Hamiltonian approach. Of the four independent color schemes, two are investigated, the $(q\bar{c})_1(c\bar{q})_1$ singlet-singlet (molecule) and the $(qc)_3(\bar{q}\bar{c})_3$ triplet-triplet (diquark), for selected $J^{PC}$ states using a variational method. The predicted masses of triplet-triplet tetraquarks are roughly a GeV heavier than the singlet-singlet states. There is also an interesting flavor dependence with $(q\bar{q})_1(c\bar{c}_1)$ states about half a GeV lighter than $(q\bar{c})_1(\bar{q}c)_1$. The lightest $1^{++}$ and $1^{--}$ predictions are in agreement with the observed X(3872) and Y(4008) masses, respectively, suggesting they both have a $\omega J/ \psi$ rather than $D^*\bar D^*$ molecular type structure. This is consistent with observed $X$, $Y$ decays to $\pi^\pm J/ \psi$ and not $D^*\bar D^*$ .
[ { "created": "Fri, 22 Feb 2013 22:54:50 GMT", "version": "v1" }, { "created": "Thu, 11 Jul 2013 13:09:30 GMT", "version": "v2" } ]
2013-07-12
[ [ "Xie", "W.", "" ], [ "Mo", "L. Q.", "" ], [ "Wang", "P.", "" ], [ "Cotanch", "Stephen R.", "" ] ]
The spectrum of tetraquark states with hidden charm is studied within an effective QCD Coulomb gauge Hamiltonian approach. Of the four independent color schemes, two are investigated, the $(q\bar{c})_1(c\bar{q})_1$ singlet-singlet (molecule) and the $(qc)_3(\bar{q}\bar{c})_3$ triplet-triplet (diquark), for selected $J^{PC}$ states using a variational method. The predicted masses of triplet-triplet tetraquarks are roughly a GeV heavier than the singlet-singlet states. There is also an interesting flavor dependence with $(q\bar{q})_1(c\bar{c}_1)$ states about half a GeV lighter than $(q\bar{c})_1(\bar{q}c)_1$. The lightest $1^{++}$ and $1^{--}$ predictions are in agreement with the observed X(3872) and Y(4008) masses, respectively, suggesting they both have a $\omega J/ \psi$ rather than $D^*\bar D^*$ molecular type structure. This is consistent with observed $X$, $Y$ decays to $\pi^\pm J/ \psi$ and not $D^*\bar D^*$ .
hep-ph/9703413
Gerald Dunne
V.A. Miransky
Conformal Phase Transition
27 pages,latex (with sprocl.sty),no figures. Invited talk presented at "Strongly Coupled Gauge Theories, 1996", Nagoya, Japan, November 1996
null
null
ITP-97-09
hep-ph
null
The conception of the conformal phase transition (CPT), which is relevant for the description of non-perturbative dynamics in gauge theories, is discussed.
[ { "created": "Tue, 25 Mar 1997 14:13:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Miransky", "V. A.", "" ] ]
The conception of the conformal phase transition (CPT), which is relevant for the description of non-perturbative dynamics in gauge theories, is discussed.
1109.5896
Alka Upadhyay
M. Batra, A. Upadhyay
Scalar and Tensor Sea Contributions to Nucleons
null
Proceeding of DAE-BRNS symposium, Vol. 56, 266 (2011)
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Statistical approach for proton and neutron have been used to study the low energy properties of nucleons. Nucleons is assumed as a composite system of three quarks and "sea" where sea is assumed to be in S-wave consisting of quark-antiquark pairs (u]\bar{u},d\bar{d} only) and gluons. Here the contributions from scalar, vector and tensor sea is taken into consideration to find {\alpha} and {\beta}. Distribution of spin among valence quarks and sea-quark for proton and neutron are denoted by I_1^pand I_1^n respectively. Statistical model predicted the values as 0.132 and -0.011 which is close to EMC experimental value 0.136 and -0.013 for I_1^p and I_1^n respectively. Although the statistical model predictions give close to EMC data for neutron spin distribution. The results have also been compared with the Simple quark model results that matches well with SU(6) model..
[ { "created": "Tue, 27 Sep 2011 14:03:35 GMT", "version": "v1" } ]
2012-02-01
[ [ "Batra", "M.", "" ], [ "Upadhyay", "A.", "" ] ]
Statistical approach for proton and neutron have been used to study the low energy properties of nucleons. Nucleons is assumed as a composite system of three quarks and "sea" where sea is assumed to be in S-wave consisting of quark-antiquark pairs (u]\bar{u},d\bar{d} only) and gluons. Here the contributions from scalar, vector and tensor sea is taken into consideration to find {\alpha} and {\beta}. Distribution of spin among valence quarks and sea-quark for proton and neutron are denoted by I_1^pand I_1^n respectively. Statistical model predicted the values as 0.132 and -0.011 which is close to EMC experimental value 0.136 and -0.013 for I_1^p and I_1^n respectively. Although the statistical model predictions give close to EMC data for neutron spin distribution. The results have also been compared with the Simple quark model results that matches well with SU(6) model..
2201.03963
Armando Bermudez Martinez
Armando Bermudez Martinez, Luis Ignacio Estevez Banos, Miguel Fernandez Moreira, Joel Girones Dominguez, Hannes Jung and Reiner Ramos Blazquez
Drell Yan production in the parton branching method and POWHEG matching
Part of the DESY summerstudent program 2021 (DESYsummer2021)
null
null
DESY-21-221
hep-ph
http://creativecommons.org/licenses/by/4.0/
As part of the DESY summer student program 2021, transverse momentum dependent (TMD) parton distributions obtained from the Parton Branching (PB) method were combined with next-to-leading-order (NLO) using the POWHEG method. Computations of the resulting Drell-Yan (DY) transverse momentum spectrum were performed. A good agreement of the theoretical predictions with the measurement performed by the CMS experiment at the center-of-mass energy of 13 TeV is found, at low and intermediate DY $p_{\rm T}$. The new scale choice option for the matching has been included in the CASCADE event generator.
[ { "created": "Tue, 11 Jan 2022 14:20:54 GMT", "version": "v1" } ]
2022-01-12
[ [ "Martinez", "Armando Bermudez", "" ], [ "Banos", "Luis Ignacio Estevez", "" ], [ "Moreira", "Miguel Fernandez", "" ], [ "Dominguez", "Joel Girones", "" ], [ "Jung", "Hannes", "" ], [ "Blazquez", "Reiner Ramos", "" ] ]
As part of the DESY summer student program 2021, transverse momentum dependent (TMD) parton distributions obtained from the Parton Branching (PB) method were combined with next-to-leading-order (NLO) using the POWHEG method. Computations of the resulting Drell-Yan (DY) transverse momentum spectrum were performed. A good agreement of the theoretical predictions with the measurement performed by the CMS experiment at the center-of-mass energy of 13 TeV is found, at low and intermediate DY $p_{\rm T}$. The new scale choice option for the matching has been included in the CASCADE event generator.
1902.03866
Yu-xin Liu
Xiang Li, Wei-jie Fu, Yu-xin Liu
Thermodynamics of 2+1 Flavor Polyakov-Loop Quark-Meson Model under External Magnetic Field
12 pages, 9 figures. Discussions and References are added. Typos are corrected. To appear in Phys. Rev. D
Phys. Rev. D 99, 074029 (2019)
10.1103/PhysRevD.99.074029
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the thermodynamics of QCD system under external magnetic field via the 2+1 flavor Polyakov-loop quark-meson model. To incorporate quantum and thermal fluctuations, the functional renormalization group approach is implemented in our work. Pressure, entropy density, magnetic susceptibility and other thermodynamic quantities are calculated and analyzed to investigate the effect of magnetic field on the QCD system. The calculated results are in reasonable agreement with lattice QCD simulations and perturbation theory. We then give an intuitive picture for the response of QCD system to the magnetic field.
[ { "created": "Mon, 11 Feb 2019 13:34:23 GMT", "version": "v1" }, { "created": "Tue, 19 Feb 2019 13:42:27 GMT", "version": "v2" }, { "created": "Thu, 4 Apr 2019 01:03:16 GMT", "version": "v3" } ]
2019-05-02
[ [ "Li", "Xiang", "" ], [ "Fu", "Wei-jie", "" ], [ "Liu", "Yu-xin", "" ] ]
We study the thermodynamics of QCD system under external magnetic field via the 2+1 flavor Polyakov-loop quark-meson model. To incorporate quantum and thermal fluctuations, the functional renormalization group approach is implemented in our work. Pressure, entropy density, magnetic susceptibility and other thermodynamic quantities are calculated and analyzed to investigate the effect of magnetic field on the QCD system. The calculated results are in reasonable agreement with lattice QCD simulations and perturbation theory. We then give an intuitive picture for the response of QCD system to the magnetic field.
hep-ph/9512208
Stefano Forte
Stefano Forte and Richard D. Ball
Universality and Scaling in Perturbative QCD at Small x
35 pages, TeX with epsf, 12 figures in compressed postscript
Acta Phys.Polon.B26:2097-2134,1995
null
CERN-TH/95-323, Edinburgh 95/560
hep-ph
null
We present a pedagogical review of the universal scaling properties displayed by the structure function F_2 at small x and large Q^2 as measured at HERA. We first describe the derivation of the double asymptotic scaling of F_2 from the leading-order Altarelli-Parisi equations of perturbative QCD. Universal next-to-leading order corrections to scaling are also derived. We explain why the universal scaling behaviour is spoiled when the initial distributions rise too steeply by considering the nonsinglet distribution F_2^p-F_2^n as an explicit example. We then examine the stability of double scaling to the inclusion of higher order singularities, explaining how the perturbative expansion at small x can be reorganized in such a way that each order is given by the sum of a convergent series of contributions which are of arbitrarily high order in the coupling. The wave-like nature of perturbative evolution is then shown to persist throughout almost all the small x region, giving rise asymptotically to double scaling for a wide class of boundary conditions.
[ { "created": "Fri, 1 Dec 1995 18:03:56 GMT", "version": "v1" } ]
2014-11-17
[ [ "Forte", "Stefano", "" ], [ "Ball", "Richard D.", "" ] ]
We present a pedagogical review of the universal scaling properties displayed by the structure function F_2 at small x and large Q^2 as measured at HERA. We first describe the derivation of the double asymptotic scaling of F_2 from the leading-order Altarelli-Parisi equations of perturbative QCD. Universal next-to-leading order corrections to scaling are also derived. We explain why the universal scaling behaviour is spoiled when the initial distributions rise too steeply by considering the nonsinglet distribution F_2^p-F_2^n as an explicit example. We then examine the stability of double scaling to the inclusion of higher order singularities, explaining how the perturbative expansion at small x can be reorganized in such a way that each order is given by the sum of a convergent series of contributions which are of arbitrarily high order in the coupling. The wave-like nature of perturbative evolution is then shown to persist throughout almost all the small x region, giving rise asymptotically to double scaling for a wide class of boundary conditions.
2203.12714
Roni Harnik
Asher Berlin, Sergey Belomestnykh, Diego Blas, Daniil Frolov, Anthony J. Brady, Caterina Braggio, Marcela Carena, Raphael Cervantes, Mattia Checchin, Crispin Contreras-Martinez, Raffaele Tito D'Agnolo, Sebastian A. R. Ellis, Grigory Eremeev, Christina Gao, Bianca Giaccone, Anna Grassellino, Roni Harnik, Matthew Hollister, Ryan Janish, Yonatan Kahn, Sergey Kazakov, Doga Murat Kurkcuoglu, Zhen Liu, Andrei Lunin, Alexander Netepenko, Oleksandr Melnychuk, Roman Pilipenko, Yuriy Pischalnikov, Sam Posen, Alex Romanenko, Jan Schutte-Engel, Changqing Wang, Vyacheslav Yakovlev, Kevin Zhou, Silvia Zorzetti, Quntao Zhuang
Searches for New Particles, Dark Matter, and Gravitational Waves with SRF Cavities
Submitted to the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021). 19 pages, 21 figures
null
null
FERMILAB-PUB-22-150-SQMS-T
hep-ph hep-ex
http://creativecommons.org/publicdomain/zero/1.0/
This is a Snowmass white paper on the utility of existing and future superconducting cavities to probe fundamental physics. Superconducting radio frequency (SRF) cavity technology has seen tremendous progress in the past decades, as a tool for accelerator science. With advances spear-headed by the SQMS center at Fermilab, they are now being brought to the quantum regime becoming a tool in quantum science thanks to the high degree of coherence. The same high quality factor can be leveraged in the search for new physics, including searches for new particles, dark matter, including the QCD axion, and gravitational waves. We survey some of the physics opportunities and the required directions of R&D. Given the already demonstrated integration of SRF cavities in large accelerator systems, this R&D may enable larger scale searches by dedicated experiments.
[ { "created": "Wed, 23 Mar 2022 20:37:58 GMT", "version": "v1" } ]
2022-03-25
[ [ "Berlin", "Asher", "" ], [ "Belomestnykh", "Sergey", "" ], [ "Blas", "Diego", "" ], [ "Frolov", "Daniil", "" ], [ "Brady", "Anthony J.", "" ], [ "Braggio", "Caterina", "" ], [ "Carena", "Marcela", "" ], ...
This is a Snowmass white paper on the utility of existing and future superconducting cavities to probe fundamental physics. Superconducting radio frequency (SRF) cavity technology has seen tremendous progress in the past decades, as a tool for accelerator science. With advances spear-headed by the SQMS center at Fermilab, they are now being brought to the quantum regime becoming a tool in quantum science thanks to the high degree of coherence. The same high quality factor can be leveraged in the search for new physics, including searches for new particles, dark matter, including the QCD axion, and gravitational waves. We survey some of the physics opportunities and the required directions of R&D. Given the already demonstrated integration of SRF cavities in large accelerator systems, this R&D may enable larger scale searches by dedicated experiments.
2105.06572
Daniel Boyanovsky
Mudit Rai, Lisong Chen, Daniel Boyanovsky
Infrared dressing in real time: emergence of anomalous dimensions
published version. more comments and discussions same results
Phys. Rev. D 104, 085021 (2021)
10.1103/PhysRevD.104.085021
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We implement a dynamical resummation method (DRM) as an extension of the dynamical renormalization group to study the time evolution of infrared dressing in non-gauge theories. Super renormalizable and renormalizable models feature infrared divergences similar to those of a theory at a critical point, motivating a renormalization group improvement of the propagator that yields a power law decay of the survival probability $\propto t^{-\Delta}$. The (DRM) confirms this decay, yields the dressed state and determines that the anomalous dimension $\Delta$ is completely determined by the slope of the spectral density at threshold independent of the ultraviolet behavior, suggesting certain universality for infrared phenomena. The dressed state is an entangled state of the charged and massless quanta. The entanglement entropy is obtained by tracing over the unobserved massless quanta. Its time evolution is determined by the (DRM), it is infrared finite and describes the information flow from the initial single particle to the asymptotic multiparticle dressed state. We show that effective field theories of massless axion-like particles coupled to fermion fields do not feature infrared divergences, and provide a criterion for infrared divergences in effective field theories valid for non-gauge theories up to one loop.
[ { "created": "Thu, 13 May 2021 22:28:31 GMT", "version": "v1" }, { "created": "Mon, 17 May 2021 12:19:58 GMT", "version": "v2" }, { "created": "Fri, 22 Oct 2021 21:15:45 GMT", "version": "v3" } ]
2021-10-26
[ [ "Rai", "Mudit", "" ], [ "Chen", "Lisong", "" ], [ "Boyanovsky", "Daniel", "" ] ]
We implement a dynamical resummation method (DRM) as an extension of the dynamical renormalization group to study the time evolution of infrared dressing in non-gauge theories. Super renormalizable and renormalizable models feature infrared divergences similar to those of a theory at a critical point, motivating a renormalization group improvement of the propagator that yields a power law decay of the survival probability $\propto t^{-\Delta}$. The (DRM) confirms this decay, yields the dressed state and determines that the anomalous dimension $\Delta$ is completely determined by the slope of the spectral density at threshold independent of the ultraviolet behavior, suggesting certain universality for infrared phenomena. The dressed state is an entangled state of the charged and massless quanta. The entanglement entropy is obtained by tracing over the unobserved massless quanta. Its time evolution is determined by the (DRM), it is infrared finite and describes the information flow from the initial single particle to the asymptotic multiparticle dressed state. We show that effective field theories of massless axion-like particles coupled to fermion fields do not feature infrared divergences, and provide a criterion for infrared divergences in effective field theories valid for non-gauge theories up to one loop.
1408.3565
Giovanni Marco Pruna Dr
Giovanni Marco Pruna and Adrian Signer
The $\mu\to e\gamma$ decay in a systematic effective field theory approach with dimension 6 operators
37 pages, 2 figures. V2 matches the published version
Journal of High Energy Physics, October 2014, 2014:14
10.1007/JHEP10(2014)014
PSI-PR-14-07, ZU-TH 25/14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We implement a systematic effective field theory approach to the benchmark process $\mu\to e \gamma$, performing automated one-loop computations including dimension 6 operators and studying their anomalous dimensions. We obtain limits on Wilson coefficients of a relevant subset of lepton-flavour violating operators that contribute to the branching ratio $\mu\to e \gamma$ at one-loop. In addition, we illustrate a method to extract further constraints induced by the mixing of operators under renormalisation-group evolution. This results in limits on the corresponding Wilson coefficients directly at the high scale. The procedure can be applied to other processes as well and, as an example, we consider also lepton-flavour violating decays of the $\tau$.
[ { "created": "Fri, 15 Aug 2014 15:34:31 GMT", "version": "v1" }, { "created": "Wed, 8 Oct 2014 17:20:06 GMT", "version": "v2" } ]
2014-10-09
[ [ "Pruna", "Giovanni Marco", "" ], [ "Signer", "Adrian", "" ] ]
We implement a systematic effective field theory approach to the benchmark process $\mu\to e \gamma$, performing automated one-loop computations including dimension 6 operators and studying their anomalous dimensions. We obtain limits on Wilson coefficients of a relevant subset of lepton-flavour violating operators that contribute to the branching ratio $\mu\to e \gamma$ at one-loop. In addition, we illustrate a method to extract further constraints induced by the mixing of operators under renormalisation-group evolution. This results in limits on the corresponding Wilson coefficients directly at the high scale. The procedure can be applied to other processes as well and, as an example, we consider also lepton-flavour violating decays of the $\tau$.
1609.03390
Juergen Reuter
Bijan Chokouf\'e Nejad, Wolfgang Kilian, Jonas M. Lindert, Stefano Pozzorini, J\"urgen Reuter, Christian Weiss
NLO QCD Predictions for off-shell $t \bar t$ and $t \bar t H$ Production and Decay at a Linear Collider
42 pages, 21 figures
JHEP 1612 (2016) 075
10.1007/JHEP12(2016)075
DESY 16-140, SI-HEP-2016-24, ZU-TH 30/16
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We present predictions for $t \bar t$ and $t \bar t H$ production and decay at future lepton colliders including non-resonant and interference contributions up to next-to-leading order (NLO) in perturbative QCD. The obtained precision predictions are necessary for a future precise determination of the top-quark Yukawa coupling, and allow for top-quark phenomenology in the continuum at an unprecedented level of accuracy. Simulations are performed with the automated NLO Monte-Carlo framework WHIZARD interfaced to the OpenLoops matrix element generator.
[ { "created": "Mon, 12 Sep 2016 13:35:25 GMT", "version": "v1" } ]
2017-01-03
[ [ "Nejad", "Bijan Chokoufé", "" ], [ "Kilian", "Wolfgang", "" ], [ "Lindert", "Jonas M.", "" ], [ "Pozzorini", "Stefano", "" ], [ "Reuter", "Jürgen", "" ], [ "Weiss", "Christian", "" ] ]
We present predictions for $t \bar t$ and $t \bar t H$ production and decay at future lepton colliders including non-resonant and interference contributions up to next-to-leading order (NLO) in perturbative QCD. The obtained precision predictions are necessary for a future precise determination of the top-quark Yukawa coupling, and allow for top-quark phenomenology in the continuum at an unprecedented level of accuracy. Simulations are performed with the automated NLO Monte-Carlo framework WHIZARD interfaced to the OpenLoops matrix element generator.
1811.08913
Tamas Cs\"org\H{o}
T. Csorgo, R. Pasechnik and A. Ster
Model-independent femtoscopic Levy imaging for elastic proton-proton scattering
8 pages, 2x2 figures, 2 Tables. Invited talk of T. Csorgo at WPCF 2019 at JINR, Dubna, Russia, submitted to the proceedings. Physics of Elementary Particles and Nuclei (PEPAN), in press
Physics of Particles and Nuclei v. 51 (3) pp. 227-231 (2020)
null
null
hep-ph hep-ex nucl-ex nucl-th physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A model independent Levy expansion method is introduced to describe nearly Levy shaped squared moduli of Fourier transforms. We apply this method to precisely characterize the most recent elastic scattering data of proton-proton collisions at $\sqrt{s} = 13$ TeV. The results reveal a substructure of protons, which is found to be significantly larger and darker in high energy proton-proton collisions at the TeV scale, as compared to a rather faint and apparently overlooked sub-structure, that we also identify in elastic proton-proton scattering at the ISR energy range of $\sqrt{s} = 23 - 62$ GeV.
[ { "created": "Wed, 21 Nov 2018 19:00:31 GMT", "version": "v1" }, { "created": "Thu, 13 Dec 2018 22:29:27 GMT", "version": "v2" }, { "created": "Fri, 4 Oct 2019 21:40:44 GMT", "version": "v3" } ]
2020-05-01
[ [ "Csorgo", "T.", "" ], [ "Pasechnik", "R.", "" ], [ "Ster", "A.", "" ] ]
A model independent Levy expansion method is introduced to describe nearly Levy shaped squared moduli of Fourier transforms. We apply this method to precisely characterize the most recent elastic scattering data of proton-proton collisions at $\sqrt{s} = 13$ TeV. The results reveal a substructure of protons, which is found to be significantly larger and darker in high energy proton-proton collisions at the TeV scale, as compared to a rather faint and apparently overlooked sub-structure, that we also identify in elastic proton-proton scattering at the ISR energy range of $\sqrt{s} = 23 - 62$ GeV.
1309.3631
Ahmed Rashed Mr
Ahmed Rashed
Tau neutrino as a probe of nonstandard interactions via charged Higgs and $W'$ contribution
Presentation at the DPF 2013 Meeting of the American Physical Society Division of Particles and Fields, Santa Cruz, California, August 13-17, 2013
Mod. Phys. Lett. A, Vol. 29, No. 7 (2014) 1450040
10.1142/S0217732314500400
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the impact of the presence of a charged Higgs and a $W'$ gauge boson on the tau-neutrino nucleon scattering $\nu_{\tau}+ N \rightarrow \tau^- + X$ and $\bar{\nu}_{\tau}+ N \rightarrow \tau^+ + X$. We show the effect of the new physics on the three subprocesses quasielastic, $\Delta$-resonance, and deep inelastic scattering. The measurement of the atmospheric and reactor mixing angles $\theta_{23}$ and $\theta_{13}$, respectively, relies on the standard model cross section of the above processes if they have been measured in the appearance channels $\nu_\mu \rightarrow \nu_\tau$ and $\bar{\nu}_e \rightarrow \bar{\nu}_\tau$ ($\nu_e \rightarrow \nu_\tau$), respectively. Consideration of the new physics contributions to those reactions modifies the measured mixing angles, assuming the standard model cross section. We include form factor effects in the new physics calculations and find the deviations of the mixing angles which can be significant and can depend on the energy of the neutrino.
[ { "created": "Sat, 14 Sep 2013 07:03:36 GMT", "version": "v1" } ]
2014-03-10
[ [ "Rashed", "Ahmed", "" ] ]
We discuss the impact of the presence of a charged Higgs and a $W'$ gauge boson on the tau-neutrino nucleon scattering $\nu_{\tau}+ N \rightarrow \tau^- + X$ and $\bar{\nu}_{\tau}+ N \rightarrow \tau^+ + X$. We show the effect of the new physics on the three subprocesses quasielastic, $\Delta$-resonance, and deep inelastic scattering. The measurement of the atmospheric and reactor mixing angles $\theta_{23}$ and $\theta_{13}$, respectively, relies on the standard model cross section of the above processes if they have been measured in the appearance channels $\nu_\mu \rightarrow \nu_\tau$ and $\bar{\nu}_e \rightarrow \bar{\nu}_\tau$ ($\nu_e \rightarrow \nu_\tau$), respectively. Consideration of the new physics contributions to those reactions modifies the measured mixing angles, assuming the standard model cross section. We include form factor effects in the new physics calculations and find the deviations of the mixing angles which can be significant and can depend on the energy of the neutrino.
1508.04818
Takahiro Yoshinaga
Takahiro Yoshinaga
Prospects for Slepton Searches in Future Experiments
Dissertation submitted to Depertment of Physics, University of Tokyo (Dec. 2014). English, 121 pages, 30 figures, 8 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Muon g-2 anomaly, which is mismatch between the theoretical and the experimental values of the anomalous magnetic moment of muons, provides a sensitive probe of new physics. In SUSY, if masses of the superpartners relevant to the muon g-2 are O(100) GeV, the SUSY contributions to the muon g-2 become sizable and the anomaly can be solved. There are two representative SUSY contributions to the muon g-2, the chargino and the neutralino contributions, respectively. Particularly, when the discrepancy of the muon g-2 is dominated by the neutralino contributions, it is found that the discrepancy can be explained if only the Bino and sleptons are light. This setup is "minimal" to solve the muon g-2 anomaly. In this dissertation, we discuss the "minimal" SUSY models where only the Bino and sleptons are light, while the other superparticles are decoupled. When the slepton soft masses are universal, we show that the upper bound on the smuon mass becomes 330 (460) GeV in order to solve the muon g-2 anomaly at the 1sigma (2 sigma) level. It is within the reach of LHC and ILC. Further, light staus might affect the Higgs coupling to di-photon, which is sensitive to new physics. We also study future prospects of the stau which contributes to the Higgs coupling. If the stau is heavier than the smuon, we show that the bound can be as large as 1.4 (1.9) TeV. Such non-universal slepton mass spectrum generically predicts too large LFV/CPV. We show that the models are expected to be probed by LHC/ILC and LFV/CPV complementarily in future.
[ { "created": "Wed, 19 Aug 2015 22:34:49 GMT", "version": "v1" } ]
2015-08-21
[ [ "Yoshinaga", "Takahiro", "" ] ]
Muon g-2 anomaly, which is mismatch between the theoretical and the experimental values of the anomalous magnetic moment of muons, provides a sensitive probe of new physics. In SUSY, if masses of the superpartners relevant to the muon g-2 are O(100) GeV, the SUSY contributions to the muon g-2 become sizable and the anomaly can be solved. There are two representative SUSY contributions to the muon g-2, the chargino and the neutralino contributions, respectively. Particularly, when the discrepancy of the muon g-2 is dominated by the neutralino contributions, it is found that the discrepancy can be explained if only the Bino and sleptons are light. This setup is "minimal" to solve the muon g-2 anomaly. In this dissertation, we discuss the "minimal" SUSY models where only the Bino and sleptons are light, while the other superparticles are decoupled. When the slepton soft masses are universal, we show that the upper bound on the smuon mass becomes 330 (460) GeV in order to solve the muon g-2 anomaly at the 1sigma (2 sigma) level. It is within the reach of LHC and ILC. Further, light staus might affect the Higgs coupling to di-photon, which is sensitive to new physics. We also study future prospects of the stau which contributes to the Higgs coupling. If the stau is heavier than the smuon, we show that the bound can be as large as 1.4 (1.9) TeV. Such non-universal slepton mass spectrum generically predicts too large LFV/CPV. We show that the models are expected to be probed by LHC/ILC and LFV/CPV complementarily in future.
2206.08590
Jayden Newstead
Bhaskar Dutta, Wei-Chih Huang, Jayden L. Newstead, Vishvas Pandey
Inelastic nuclear scattering from neutrinos and dark matter
16 pages, 12 figures, published version
Phys. Rev. D 106, 113006 (2022)
10.1103/PhysRevD.106.113006
FERMILAB-PUB-22-485-ND
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrinos with energy of order 10~MeV, such as from pion decay-at-rest sources, are an invaluable tool for studying low-energy neutrino interactions with nuclei -- previously enabling the first measurement of coherent elastic neutrino-nucleus scattering. Beyond elastic scattering, neutrinos and dark matter in this energy range also excite nuclei to its low-lying nuclear states, providing an additional physics channel. Here, we consider neutral-current inelastic neutrino-nucleus and dark matter(DM)-nucleus scattering off $^{40}$Ar, $^{133}$Cs, and $^{127}$I nuclei that are relevant to a number of low-threshold neutrino experiments at pion decay-at-rest facilities. We carry out large scale nuclear shell model calculations of the inelastic cross sections considering the full set of electroweak multipole operators. Our results demonstrate that Gamow-Teller transitions provide the dominant contribution to the cross section and that the long-wavelength limit provides a reasonable approximation to the total cross section for neutrino sources. We show that future experiments will be sensitive to this channel and thus these results provide additional neutrino and DM scattering channels to explore at pion decay-at-rest facilities.
[ { "created": "Fri, 17 Jun 2022 07:25:30 GMT", "version": "v1" }, { "created": "Tue, 20 Dec 2022 03:02:40 GMT", "version": "v2" } ]
2022-12-23
[ [ "Dutta", "Bhaskar", "" ], [ "Huang", "Wei-Chih", "" ], [ "Newstead", "Jayden L.", "" ], [ "Pandey", "Vishvas", "" ] ]
Neutrinos with energy of order 10~MeV, such as from pion decay-at-rest sources, are an invaluable tool for studying low-energy neutrino interactions with nuclei -- previously enabling the first measurement of coherent elastic neutrino-nucleus scattering. Beyond elastic scattering, neutrinos and dark matter in this energy range also excite nuclei to its low-lying nuclear states, providing an additional physics channel. Here, we consider neutral-current inelastic neutrino-nucleus and dark matter(DM)-nucleus scattering off $^{40}$Ar, $^{133}$Cs, and $^{127}$I nuclei that are relevant to a number of low-threshold neutrino experiments at pion decay-at-rest facilities. We carry out large scale nuclear shell model calculations of the inelastic cross sections considering the full set of electroweak multipole operators. Our results demonstrate that Gamow-Teller transitions provide the dominant contribution to the cross section and that the long-wavelength limit provides a reasonable approximation to the total cross section for neutrino sources. We show that future experiments will be sensitive to this channel and thus these results provide additional neutrino and DM scattering channels to explore at pion decay-at-rest facilities.
1703.07893
Fernando Iguaz\'u Ram\'irez-Zavaleta
J. I. Aranda, E. Cruz-Albaro, D. Espinosa-G\'omez, J. Monta\~no, F. Ram\'irez-Zavaleta, E. S. Tututi
Heavy neutral pseudoscalar decays into gauge bosons in the Littlest Higgs Model
12 pages and 9 figures
null
10.1088/1361-6471/aa846d
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study two-body decays of a new neutral pseudoscalar into gauge bosons within the context of the Littlest Higgs model. Concretely, the $\Phi^P \to WW, VV, gg$ processes induced at the one-loop level, with $V=\gamma, Z$, are considered. Since the branching ratios of the $\Phi^P \to VV$ decays result very suppressed, only the $\Phi^P \to WW, gg$ processes are thoroughly studied. The branching ratios for the $\Phi^P \to gg$ and $\Phi^P \to WW$ decays are of the order of $10^{-4}$ and $10^{-6}$, respectively, for $f$ around 2 TeV, which represents the global symmetry breaking scale of the theory. The production cross section of the $\Phi^P$ boson via gluon fusion at LHC is estimated.
[ { "created": "Thu, 23 Mar 2017 00:17:50 GMT", "version": "v1" } ]
2017-09-13
[ [ "Aranda", "J. I.", "" ], [ "Cruz-Albaro", "E.", "" ], [ "Espinosa-Gómez", "D.", "" ], [ "Montaño", "J.", "" ], [ "Ramírez-Zavaleta", "F.", "" ], [ "Tututi", "E. S.", "" ] ]
We study two-body decays of a new neutral pseudoscalar into gauge bosons within the context of the Littlest Higgs model. Concretely, the $\Phi^P \to WW, VV, gg$ processes induced at the one-loop level, with $V=\gamma, Z$, are considered. Since the branching ratios of the $\Phi^P \to VV$ decays result very suppressed, only the $\Phi^P \to WW, gg$ processes are thoroughly studied. The branching ratios for the $\Phi^P \to gg$ and $\Phi^P \to WW$ decays are of the order of $10^{-4}$ and $10^{-6}$, respectively, for $f$ around 2 TeV, which represents the global symmetry breaking scale of the theory. The production cross section of the $\Phi^P$ boson via gluon fusion at LHC is estimated.
2211.04414
Marc Winstel
Marc Winstel, Laurin Pannullo
Stability of homogeneous chiral phases against inhomogeneous perturbations in 2+1 dimensions
10 pages, 1 figure, contains ancillary files with plot data; talk given at the 39th International Symposium on Lattice Field theory (LATTICE 2022) in Bonn; August 8-13 2022
null
10.22323/1.430.0195
null
hep-ph cond-mat.str-el hep-lat
http://creativecommons.org/licenses/by-nc-nd/4.0/
In this work, inhomogeneous chiral phases are studied in a variety of Four-Fermion and Yukawa models in $2+1$ dimensions at zero and non-zero temperature and chemical potentials. Employing the mean-field approximation, we do not find indications for an inhomogeneous phase in any of the studied models. We show that the homogeneous phases are stable against inhomogeneous perturbations. At zero temperature, full analytic results are presented.
[ { "created": "Tue, 8 Nov 2022 17:59:46 GMT", "version": "v1" } ]
2023-02-08
[ [ "Winstel", "Marc", "" ], [ "Pannullo", "Laurin", "" ] ]
In this work, inhomogeneous chiral phases are studied in a variety of Four-Fermion and Yukawa models in $2+1$ dimensions at zero and non-zero temperature and chemical potentials. Employing the mean-field approximation, we do not find indications for an inhomogeneous phase in any of the studied models. We show that the homogeneous phases are stable against inhomogeneous perturbations. At zero temperature, full analytic results are presented.
1611.03297
Zhi-Wei Wang
Zhi-Wei Wang, Frederick S. Sage, T.G. Steele, R.B. Mann, T. Hanif
Conformal Complex Scalar Singlet Extensions of the Standard Model: Symmetry Breaking Patterns and Phenomenology
4 pages, 2 figures, Contribution to the proceedings of the 38th International Conference of High Energy Physics (ICHEP), Chicago, Aug. 3-10, 2016
null
null
CP3-Origins-2016-47 DNRF90
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. Two different scenarios depending on whether the global U(1) symmetry is broken or not have been studied. In the unbroken phase, the decay of the complex singlet is protected by the global U(1) symmetry which leads to an ideal cold dark matter candidate. In the broken phase, we are able to provide a second Higgs at $554\,\rm{GeV}$. In addition, gauging the global U(1) symmetry, we can construct an asymptotically safe U(1)' leptophobic model. We combine the notion of asymptotic safety with conformal symmetry and use the renormalization group equations as a bridge to connect UV boundary conditions and Electroweak/ TeV scale physics. We also provide a detailed example to show that these boundary conditions will lead to phenomenological signatures such as diboson excesses which could be tested at the LHC.
[ { "created": "Thu, 10 Nov 2016 13:30:40 GMT", "version": "v1" } ]
2016-11-11
[ [ "Wang", "Zhi-Wei", "" ], [ "Sage", "Frederick S.", "" ], [ "Steele", "T. G.", "" ], [ "Mann", "R. B.", "" ], [ "Hanif", "T.", "" ] ]
We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. Two different scenarios depending on whether the global U(1) symmetry is broken or not have been studied. In the unbroken phase, the decay of the complex singlet is protected by the global U(1) symmetry which leads to an ideal cold dark matter candidate. In the broken phase, we are able to provide a second Higgs at $554\,\rm{GeV}$. In addition, gauging the global U(1) symmetry, we can construct an asymptotically safe U(1)' leptophobic model. We combine the notion of asymptotic safety with conformal symmetry and use the renormalization group equations as a bridge to connect UV boundary conditions and Electroweak/ TeV scale physics. We also provide a detailed example to show that these boundary conditions will lead to phenomenological signatures such as diboson excesses which could be tested at the LHC.
1601.02038
Richard Gran
J. Schwehr, D. Cherdack, R. Gran
GENIE implementation of IFIC Valencia model for QE-like 2p2h neutrino-nucleus cross section
23 pages, 9 figures, technical note. Updated with scaling to full range of nuclei and GENIE 2.12.6
null
null
MINERvA experiment technical note 61
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The model by Nieves, Ruiz-Simo, and Vicente-Vacas and their group (IFIC, Valencia, Spain) for 2p2h reactions that produce QE-like (no pion) final states has been implemented in GENIE. Since the model currently does not predict the kinematics of the outgoing hadrons, a simple two-nucleon system is grafted onto the model's prediction of isospin, energy transfer, and momentum transfer. These two nucleons are then given to the GENIE FSI models. This technical note is a guide to the kind of information available from this model and some limitations. There are several figures that illustrate the output of the model, and detailed discussion of the physics context for this model. Finally, any other authors' model (or variations of this one) that can be expressed as hadronic tensors for total and pn initial state will be easy to incorporate into this framework, or possibly be made available as a reweight to events generated with this model. The 2017 version of this document is updated to reflect the as-released GENIE 2.12.6 version of the code, which produces identical results to the development versions.
[ { "created": "Fri, 8 Jan 2016 21:59:55 GMT", "version": "v1" }, { "created": "Tue, 13 Jun 2017 16:30:25 GMT", "version": "v2" } ]
2017-06-14
[ [ "Schwehr", "J.", "" ], [ "Cherdack", "D.", "" ], [ "Gran", "R.", "" ] ]
The model by Nieves, Ruiz-Simo, and Vicente-Vacas and their group (IFIC, Valencia, Spain) for 2p2h reactions that produce QE-like (no pion) final states has been implemented in GENIE. Since the model currently does not predict the kinematics of the outgoing hadrons, a simple two-nucleon system is grafted onto the model's prediction of isospin, energy transfer, and momentum transfer. These two nucleons are then given to the GENIE FSI models. This technical note is a guide to the kind of information available from this model and some limitations. There are several figures that illustrate the output of the model, and detailed discussion of the physics context for this model. Finally, any other authors' model (or variations of this one) that can be expressed as hadronic tensors for total and pn initial state will be easy to incorporate into this framework, or possibly be made available as a reweight to events generated with this model. The 2017 version of this document is updated to reflect the as-released GENIE 2.12.6 version of the code, which produces identical results to the development versions.
2304.06080
Praveen Bharadwaj
Aditya Batra, Praveen Bharadwaj, Sanjoy Mandal, Rahul Srivastava, and Jos\'e W. F. Valle
Heavy neutrino signatures from leptophilic Higgs portal in the linear seesaw
10 pages, 4 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lepton collider setups can probe the neutrino sector in the linear seesaw mechanism. Small neutrino masses are sourced by a tiny vacuum expectation value of a leptophilic scalar Higgs doublet and are mediated by Quasi-Dirac heavy neutrinos. These new particles can all be accessible to colliders. We describe novel charged Higgs and heavy neutrino production mechanisms that can be sizeable at $e^{+} e^{-}$ or $e^{-} {\gamma}$ colliders and discuss some of the associated signatures. These may shed light on the Majorana nature of neutrinos and the role of lepton number and lepton flavour symmetries.
[ { "created": "Wed, 12 Apr 2023 18:00:18 GMT", "version": "v1" } ]
2023-04-14
[ [ "Batra", "Aditya", "" ], [ "Bharadwaj", "Praveen", "" ], [ "Mandal", "Sanjoy", "" ], [ "Srivastava", "Rahul", "" ], [ "Valle", "José W. F.", "" ] ]
Lepton collider setups can probe the neutrino sector in the linear seesaw mechanism. Small neutrino masses are sourced by a tiny vacuum expectation value of a leptophilic scalar Higgs doublet and are mediated by Quasi-Dirac heavy neutrinos. These new particles can all be accessible to colliders. We describe novel charged Higgs and heavy neutrino production mechanisms that can be sizeable at $e^{+} e^{-}$ or $e^{-} {\gamma}$ colliders and discuss some of the associated signatures. These may shed light on the Majorana nature of neutrinos and the role of lepton number and lepton flavour symmetries.
1406.1791
Fl. Stancu
N. Matagne and Fl. Stancu
Baryon resonances in large $N_c$ QCD
45 pages, 5 figures, accepted for publication in Reviews of Modern Physics
null
10.1103/RevModPhys.87.211
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the current status and present open challenges of large $N_c$ QCD baryon spectroscopy. After introducing the $1/N_c$ expansion method we first shortly revisit the latest achievements for the ground state properties. Next we discuss the applicability of this method to excited states, presenting two different approaches with their advantages and disadvantages. Selected results for the spectrum and strong and electromagnetic decays are described. We also show further developments supported by the qualitative compatibility between the quark excitation picture and the meson-nucleon scattering picture. We give a quantitative comparison between results obtained from the mass formula of the $1/N_c$ expansion method and quark models and shortly discuss the implications of different large $N_c$ limits.
[ { "created": "Thu, 5 Jun 2014 13:01:13 GMT", "version": "v1" }, { "created": "Wed, 3 Dec 2014 15:28:59 GMT", "version": "v2" } ]
2015-06-19
[ [ "Matagne", "N.", "" ], [ "Stancu", "Fl.", "" ] ]
We review the current status and present open challenges of large $N_c$ QCD baryon spectroscopy. After introducing the $1/N_c$ expansion method we first shortly revisit the latest achievements for the ground state properties. Next we discuss the applicability of this method to excited states, presenting two different approaches with their advantages and disadvantages. Selected results for the spectrum and strong and electromagnetic decays are described. We also show further developments supported by the qualitative compatibility between the quark excitation picture and the meson-nucleon scattering picture. We give a quantitative comparison between results obtained from the mass formula of the $1/N_c$ expansion method and quark models and shortly discuss the implications of different large $N_c$ limits.
1511.03804
Hidekazu Tsukiji
Hidekazu Tsukiji, Hideaki Iida, Teiji Kunihiro, Akira Ohnishi, Toru T. Takahashi
Study of entropy production in Yang-Mills theory with use of Husimi function
7 pages, 5 figures, Proceeding of the 33rd International Symposium on Lattice Field Theory (Lattice 2015), 14-18 July 2015, Kobe International Conference Center, Kobe, Japan
null
null
YITP-15-93, KUNS-2592
hep-ph nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Understanding the thermalization process in a pure quantum system is a challenge in theoretical physics. In this work, we explore possible thermalization mechanism in Yang-Mills(YM) theory by using a positive semi-definite quantum distribution function called a Husimi function which is given by a coarse graining of the Wigner function within the minimum uncertainty. Then entropy is defined in terms of the Husimi function, which is called the Husimi-Wehrl(HW) entropy. We propose two numerical methods to calculate the HW entropy. We find that it is feasible to apply the semi-classical approximation with the use of classical YM equation. It should be noted that the semi-classical approximation is valid in the systems of physical interest including the early stage of heavy-ion collisions. Using a product ansatz for the Husimi function, which is confirmed to reproduce the HW entropy within 20% error (overestimate) for a few-body quantum system, we succeed in a numerical evaluation of HW entropy of YM fields and show that it surely has a finite value and increases in time.
[ { "created": "Thu, 12 Nov 2015 07:33:15 GMT", "version": "v1" } ]
2015-11-13
[ [ "Tsukiji", "Hidekazu", "" ], [ "Iida", "Hideaki", "" ], [ "Kunihiro", "Teiji", "" ], [ "Ohnishi", "Akira", "" ], [ "Takahashi", "Toru T.", "" ] ]
Understanding the thermalization process in a pure quantum system is a challenge in theoretical physics. In this work, we explore possible thermalization mechanism in Yang-Mills(YM) theory by using a positive semi-definite quantum distribution function called a Husimi function which is given by a coarse graining of the Wigner function within the minimum uncertainty. Then entropy is defined in terms of the Husimi function, which is called the Husimi-Wehrl(HW) entropy. We propose two numerical methods to calculate the HW entropy. We find that it is feasible to apply the semi-classical approximation with the use of classical YM equation. It should be noted that the semi-classical approximation is valid in the systems of physical interest including the early stage of heavy-ion collisions. Using a product ansatz for the Husimi function, which is confirmed to reproduce the HW entropy within 20% error (overestimate) for a few-body quantum system, we succeed in a numerical evaluation of HW entropy of YM fields and show that it surely has a finite value and increases in time.
1901.02987
Ryu Sawada
Masahiko Saito, Ryu Sawada, Koji Terashi, Shoji Asai
Discovery reach for wino and higgsino dark matter with a disappearing track signature at a 100 TeV $pp$ collider
10 pages, 7 figures, 4 tables
Eur. Phys. J. C 79 (2019) 469
10.1140/epjc/s10052-019-6974-2
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the theory of supersymmetry, the lightest neutralino is a dark matter candidate and is often assumed to be the lightest supersymmetric particle (LSP) as well. If the neutral wino or higgsino is dark matter, the upper limit of the LSP mass is determined by the observed relic density of dark matter. If the LSP is a nearly-pure neutral state of the wino or higgsino, the lightest chargino state is expected to have a significant lifetime due to a tiny mass difference between the LSP and the chargino. This article presents discovery potential of the 100 TeV future circular hadron collider (FCC) for the wino and higgsino dark matter using a disappearing-track signature. The search strategy to extend the discovery reach to the thermal limits of wino/higgsino dark matter is discussed with detailed studies on the background rate and the reference design of the FCC-hadron detector under possible running scenarios of the FCC-hadron machine. A proposal of modifying the detector layout and several ideas to improve the sensitivity further are also discussed.
[ { "created": "Thu, 10 Jan 2019 01:11:34 GMT", "version": "v1" }, { "created": "Mon, 17 Jun 2019 08:50:17 GMT", "version": "v2" } ]
2019-06-18
[ [ "Saito", "Masahiko", "" ], [ "Sawada", "Ryu", "" ], [ "Terashi", "Koji", "" ], [ "Asai", "Shoji", "" ] ]
Within the theory of supersymmetry, the lightest neutralino is a dark matter candidate and is often assumed to be the lightest supersymmetric particle (LSP) as well. If the neutral wino or higgsino is dark matter, the upper limit of the LSP mass is determined by the observed relic density of dark matter. If the LSP is a nearly-pure neutral state of the wino or higgsino, the lightest chargino state is expected to have a significant lifetime due to a tiny mass difference between the LSP and the chargino. This article presents discovery potential of the 100 TeV future circular hadron collider (FCC) for the wino and higgsino dark matter using a disappearing-track signature. The search strategy to extend the discovery reach to the thermal limits of wino/higgsino dark matter is discussed with detailed studies on the background rate and the reference design of the FCC-hadron detector under possible running scenarios of the FCC-hadron machine. A proposal of modifying the detector layout and several ideas to improve the sensitivity further are also discussed.
hep-ph/0009315
Wallon Samuel
A. Shuvaev (PNPI St. Petersburg) and S. Wallon (LPT Orsay)
Soft gluon cascades and BFKL equation
completely revised and rewritten version, 19 pages, latex file, 6 figures using feynman package
null
null
LPT-ORSAY 00-76
hep-ph
null
In this paper we deal with high energy scattering in the Regge limit, using a soft cascade approach. We derive an evolution equation for the gluon density in soft gluons cascades in the leading logarithmic approximation of perturbative QCD, and show that this equation reproduces BFKL equation in the forward case. The whole cascade is equivalent to a single gluon whose self-energy is responsible for gluon reggeization. The same type of equation is obtained for the QED case.
[ { "created": "Wed, 27 Sep 2000 15:58:32 GMT", "version": "v1" }, { "created": "Tue, 19 Apr 2005 16:16:28 GMT", "version": "v2" } ]
2007-05-23
[ [ "Shuvaev", "A.", "", "PNPI St. Petersburg" ], [ "Wallon", "S.", "", "LPT Orsay" ] ]
In this paper we deal with high energy scattering in the Regge limit, using a soft cascade approach. We derive an evolution equation for the gluon density in soft gluons cascades in the leading logarithmic approximation of perturbative QCD, and show that this equation reproduces BFKL equation in the forward case. The whole cascade is equivalent to a single gluon whose self-energy is responsible for gluon reggeization. The same type of equation is obtained for the QED case.
2202.12547
Claude Bourrely
Claude Bourrely, Wen-Chen Chang, Jen-Chieh Peng
Pion Partonic Distributions in the Statistical Model from Pion-induced Drell-Yan and $J/\Psi$ Production Data
8 pages, 6 figures
Physical Review D 105, 076018 (2022)
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new analysis to extract pion parton distribution functions (PDFs) within the framework of the statistical model. Starting from the statistical model first developed for the spin-1/2 nucleon, we extend this model to describe the spin-0 pion. Based on a combined fit to both the pion-induced Drell-Yan data and the pion-induced $J/\Psi$ production data, a new set of pion PDFs has been obtained. The inclusion of the $J/\Psi$ production data in the combined fit has provided additional constraints for better determining the gluon distribution in the pion. We also compare the pion PDFs obtained in the statistical model with other existing pion PDFs.
[ { "created": "Fri, 25 Feb 2022 08:21:32 GMT", "version": "v1" }, { "created": "Thu, 28 Apr 2022 07:28:19 GMT", "version": "v2" } ]
2022-04-29
[ [ "Bourrely", "Claude", "" ], [ "Chang", "Wen-Chen", "" ], [ "Peng", "Jen-Chieh", "" ] ]
We present a new analysis to extract pion parton distribution functions (PDFs) within the framework of the statistical model. Starting from the statistical model first developed for the spin-1/2 nucleon, we extend this model to describe the spin-0 pion. Based on a combined fit to both the pion-induced Drell-Yan data and the pion-induced $J/\Psi$ production data, a new set of pion PDFs has been obtained. The inclusion of the $J/\Psi$ production data in the combined fit has provided additional constraints for better determining the gluon distribution in the pion. We also compare the pion PDFs obtained in the statistical model with other existing pion PDFs.
2004.05172
Pablo Escribano
Pablo Escribano, Mario Reig, Avelino Vicente
Generalizing the Scotogenic model
26 pages, 5 figures, 1 table; v2: minor additions, matches published version
null
10.1007/JHEP07(2020)097
IFIC/20-13
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Scotogenic model is an economical setup that induces Majorana neutrino masses at the 1-loop level and includes a dark matter candidate. We discuss a generalization of the original Scotogenic model with arbitrary numbers of generations of singlet fermion and inert doublet scalar fields. First, the full form of the light neutrino mass matrix is presented, with some comments on its derivation and with special attention to some particular cases. The behavior of the theory at high energies is explored by solving the Renormalization Group Equations.
[ { "created": "Fri, 10 Apr 2020 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 21 Jul 2020 08:13:00 GMT", "version": "v2" } ]
2020-08-26
[ [ "Escribano", "Pablo", "" ], [ "Reig", "Mario", "" ], [ "Vicente", "Avelino", "" ] ]
The Scotogenic model is an economical setup that induces Majorana neutrino masses at the 1-loop level and includes a dark matter candidate. We discuss a generalization of the original Scotogenic model with arbitrary numbers of generations of singlet fermion and inert doublet scalar fields. First, the full form of the light neutrino mass matrix is presented, with some comments on its derivation and with special attention to some particular cases. The behavior of the theory at high energies is explored by solving the Renormalization Group Equations.
2103.08153
Shota Nakagawa
Shota Nakagawa, Fuminobu Takahashi, Masaki Yamada
Cosmic Birefringence Triggered by Dark Matter Domination
6 pages, 2 figures
null
10.1103/PhysRevLett.127.181103
TU-1118, IPMU21-0018
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmic birefringence is predicted if an axion-like particle (ALP) moves after the recombination. We show that this naturally happens if the ALP is coupled to the dark matter density because it then acquires a large effective mass after the matter-radiation equality. Our scenario applies to a broad range of the ALP mass $m_\phi \lesssim 10^{-28}$ eV, even smaller than the present Hubble constant. We give a simple model to realize this scenario, where dark matter is made of hidden monopoles, which give the ALP such a large effective mass through the Witten effect. The mechanism works if the ALP decay constant is of order the GUT scale without a fine-tuning of the initial misalignment angle. For smaller decay constant, the hidden monopole can be a fraction of dark matter. We also study the implications for the QCD axion, and show that the domain wall problem can be solved by the effective mass.
[ { "created": "Mon, 15 Mar 2021 06:22:59 GMT", "version": "v1" } ]
2021-11-10
[ [ "Nakagawa", "Shota", "" ], [ "Takahashi", "Fuminobu", "" ], [ "Yamada", "Masaki", "" ] ]
Cosmic birefringence is predicted if an axion-like particle (ALP) moves after the recombination. We show that this naturally happens if the ALP is coupled to the dark matter density because it then acquires a large effective mass after the matter-radiation equality. Our scenario applies to a broad range of the ALP mass $m_\phi \lesssim 10^{-28}$ eV, even smaller than the present Hubble constant. We give a simple model to realize this scenario, where dark matter is made of hidden monopoles, which give the ALP such a large effective mass through the Witten effect. The mechanism works if the ALP decay constant is of order the GUT scale without a fine-tuning of the initial misalignment angle. For smaller decay constant, the hidden monopole can be a fraction of dark matter. We also study the implications for the QCD axion, and show that the domain wall problem can be solved by the effective mass.
hep-ph/0003133
Oscar Vives
Antonio Masiero and Oscar Vives (SISSA-ISAS and INFN, Trieste)
New Physics behind the Standard Model's door?
2 references added/corrected. Lectures given by A. Masiero at the International School on Subnuclear Physics, Erice, Italy, 29 August--7 September 1999, 43 pages, 5 figures
null
10.1142/9789812811585_0007
SISSA/20/2000/EP
hep-ph
null
We review the main reasons pushing us beyond the SM and we argue in favor of new physics at the electroweak scale (hence experimentally accessible at present or near-future machines). We focus on the appealing possibility that such new physics is given by a supersymmetric (SUSY) extension of the SM. We discuss the minimal case, Constrained Minimal Supersymmetric SM, and more general (maybe more natural) cases where some of the drastic assumptions of the CMSSM are dropped. In particular, in these lectures we focus on CP violation and its relation to flavor physics in the SUSY context. CP constrains the low-energy SUSY extensions of the SM, but, at the same time, it provides new powerful tool for indirect SUSY searches.
[ { "created": "Tue, 14 Mar 2000 19:06:18 GMT", "version": "v1" }, { "created": "Sat, 22 Apr 2000 12:44:06 GMT", "version": "v2" } ]
2017-08-23
[ [ "Masiero", "Antonio", "", "SISSA-ISAS and INFN, Trieste" ], [ "Vives", "Oscar", "", "SISSA-ISAS and INFN, Trieste" ] ]
We review the main reasons pushing us beyond the SM and we argue in favor of new physics at the electroweak scale (hence experimentally accessible at present or near-future machines). We focus on the appealing possibility that such new physics is given by a supersymmetric (SUSY) extension of the SM. We discuss the minimal case, Constrained Minimal Supersymmetric SM, and more general (maybe more natural) cases where some of the drastic assumptions of the CMSSM are dropped. In particular, in these lectures we focus on CP violation and its relation to flavor physics in the SUSY context. CP constrains the low-energy SUSY extensions of the SM, but, at the same time, it provides new powerful tool for indirect SUSY searches.
0709.2759
Satoru Akiyama
Satoru Akiyama and Masahiro Kawabata
Stability of the rotating SU(3) Skyrmion
29 pages, 9 figures, references added, typos fixed
Phys.Rev.D76:096002,2007
10.1103/PhysRevD.76.096002
null
hep-ph
null
The profile functions of the SU(3) Skyrme soliton are investigated for the octet, decuplet, and antidecuplet baryons by the mean field approach. In this approach, the profile functions are affected by the spatial rotation, the flavor rotation, and the flavor symmetry breaking. The solitons are stable only in the restricted areas of the parameter space for each multiplet. When the flavor symmetry breaking is large, the area for the antidecuplet is narrow compared to those for the octet and decuplet. The parameters are determined by the baryon mass spectrum, and the deformation of the soliton has sizable effects on the masses.
[ { "created": "Tue, 18 Sep 2007 07:59:00 GMT", "version": "v1" }, { "created": "Tue, 13 Nov 2007 01:52:15 GMT", "version": "v2" } ]
2008-11-26
[ [ "Akiyama", "Satoru", "" ], [ "Kawabata", "Masahiro", "" ] ]
The profile functions of the SU(3) Skyrme soliton are investigated for the octet, decuplet, and antidecuplet baryons by the mean field approach. In this approach, the profile functions are affected by the spatial rotation, the flavor rotation, and the flavor symmetry breaking. The solitons are stable only in the restricted areas of the parameter space for each multiplet. When the flavor symmetry breaking is large, the area for the antidecuplet is narrow compared to those for the octet and decuplet. The parameters are determined by the baryon mass spectrum, and the deformation of the soliton has sizable effects on the masses.
1411.2117
Zhi-Feng Sun
Zhi-Feng Sun, Zhan-Wei Liu, Xiang Liu, and Shi-Lin Zhu
The masses and axial currents of the doubly charmed baryons
10 pages, 2 tables, 3 figure. Accepted by Phys. Rev. D
Phys. Rev. D 91, 094030 (2015)
10.1103/PhysRevD.91.094030
ADP-14-33/T892
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The chiral dynamics of the doubly heavy baryons is solely governed by the light quark. In this work, We have derived the chiral corrections to the mass of the doubly heavy baryons up to N$^3$LO. The mass splitting of $\Xi_{cc}$ and $\Omega_{cc}$ at the N$^2$LO depends on one unknown low energy constant $c_7$. With the experimental mass of $\Xi_{cc}(3520)$ as the input, we estimate the mass of $\Omega_{cc}$ to be around 3.678 GeV. Moreover, we have also performed a systematical analysis of the chiral corrections to the axial currents and axial charges of the doubly heavy baryons. The chiral structure and analytical expressions will be very useful to the chiral extrapolations of the future lattice QCD simulations of the doubly heavy baryons.
[ { "created": "Sat, 8 Nov 2014 13:11:19 GMT", "version": "v1" }, { "created": "Sat, 9 May 2015 17:27:22 GMT", "version": "v2" }, { "created": "Sun, 31 May 2015 16:35:39 GMT", "version": "v3" } ]
2015-06-09
[ [ "Sun", "Zhi-Feng", "" ], [ "Liu", "Zhan-Wei", "" ], [ "Liu", "Xiang", "" ], [ "Zhu", "Shi-Lin", "" ] ]
The chiral dynamics of the doubly heavy baryons is solely governed by the light quark. In this work, We have derived the chiral corrections to the mass of the doubly heavy baryons up to N$^3$LO. The mass splitting of $\Xi_{cc}$ and $\Omega_{cc}$ at the N$^2$LO depends on one unknown low energy constant $c_7$. With the experimental mass of $\Xi_{cc}(3520)$ as the input, we estimate the mass of $\Omega_{cc}$ to be around 3.678 GeV. Moreover, we have also performed a systematical analysis of the chiral corrections to the axial currents and axial charges of the doubly heavy baryons. The chiral structure and analytical expressions will be very useful to the chiral extrapolations of the future lattice QCD simulations of the doubly heavy baryons.
1902.09799
Javier Vijande Asenjo
Javier Vijande, Jean-Marc Richard and Alfredo Valcarce
Few-body insights of multiquark exotic hadrons
Plenary talk at the XXII International Conference on Few-Body Problems in Physics (FB22)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this contribution we discuss the adequate treatment of the $4-$ and $5-$body dynamics within a constituent quark framework. We stress that the variational and Born-Oppenheimer approximations give energies rather close to the exact ones, while the diquark approximation might be rather misleading. Hall-Post inequalities provide very useful lower bounds that exclude possible stable states for some mass ratios and color wave functions.
[ { "created": "Tue, 26 Feb 2019 08:43:25 GMT", "version": "v1" } ]
2019-02-27
[ [ "Vijande", "Javier", "" ], [ "Richard", "Jean-Marc", "" ], [ "Valcarce", "Alfredo", "" ] ]
In this contribution we discuss the adequate treatment of the $4-$ and $5-$body dynamics within a constituent quark framework. We stress that the variational and Born-Oppenheimer approximations give energies rather close to the exact ones, while the diquark approximation might be rather misleading. Hall-Post inequalities provide very useful lower bounds that exclude possible stable states for some mass ratios and color wave functions.
hep-ph/0212008
Z. Xiao
Zhenjun Xiao and Liping Yao
Rare decay $B \to X_{s} \nu \bar \nu$ in the two-Higgs-doublet model of type-III
10 pages, 3 figures in eps and 1 in ps, Latex file
Commun.Theor.Phys.38:683-686,2002
10.1088/0253-6102/38/6/683
null
hep-ph
null
In this paper, we calculated the new physics contribution to theoretically very clean rare decay $B\to X_{s} \nu \bar{\nu}$ in the general two-Higgs-doublet model (model III). Within the considered parameter space, we found that (a) the new physics contribution can provide one to two orders of enhancement to the branching ratio $\calb(B\to X_s \nu \bar{\nu})$ and can saturate the experimental bound on $\calb(B \to X_s \nu \bar{\nu})$ in some regions of the parameter space; (b) besides the CLEO data of $B \to X_s \gamma$, the ALEPH upper limit on $\calb (B \to X_s \nu \bar{\nu})$ also lead to further constraint on the size of the Yukawa coupling $\lambda_{tt}$: $\lambda_{tt}< 6.4$ for $\lambda_{bb}=2.7$ and $\mhp=200$ GeV.
[ { "created": "Sun, 1 Dec 2002 04:08:39 GMT", "version": "v1" }, { "created": "Wed, 11 Dec 2002 09:38:19 GMT", "version": "v2" } ]
2018-01-17
[ [ "Xiao", "Zhenjun", "" ], [ "Yao", "Liping", "" ] ]
In this paper, we calculated the new physics contribution to theoretically very clean rare decay $B\to X_{s} \nu \bar{\nu}$ in the general two-Higgs-doublet model (model III). Within the considered parameter space, we found that (a) the new physics contribution can provide one to two orders of enhancement to the branching ratio $\calb(B\to X_s \nu \bar{\nu})$ and can saturate the experimental bound on $\calb(B \to X_s \nu \bar{\nu})$ in some regions of the parameter space; (b) besides the CLEO data of $B \to X_s \gamma$, the ALEPH upper limit on $\calb (B \to X_s \nu \bar{\nu})$ also lead to further constraint on the size of the Yukawa coupling $\lambda_{tt}$: $\lambda_{tt}< 6.4$ for $\lambda_{bb}=2.7$ and $\mhp=200$ GeV.
1709.02218
George W.-S. Hou
George W.-S. Hou
$P_5'$ Anomaly for Top: $tZ'$ Production at LHC
6 pages, 8 figures. Talk presented at the APS Division of Particles and Fields Meeting (DPF 2017), July 31-August 4, 2017, Fermilab. C170731
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $P_5'$ anomaly uncovered by the LHCb experiment in $B \to K^*\mu\mu$ angular observables has motivated a possible $Z'$ boson that couples to left-handed $b \to s$ transitions, where a model would be gauged $L_\mu - L_\tau$ symmetry, but direct search for such a $Z'$ is not promising. Less constrained is an analogous $Z'$ coupling to right-handed $t \to c$ transitions. Motivated by this, we study $cg \to tZ'$ associated production at LHC, both for a generic model, and in $L_\mu - L_\tau$ with a vector-like U quark. We also study $c\bar c \to Z'$ production that exists within the model. Both processes can be probed already with LHC Run 2 data, all the way up to the HL-LHC with discovery potential.
[ { "created": "Thu, 7 Sep 2017 13:02:50 GMT", "version": "v1" } ]
2017-09-08
[ [ "Hou", "George W. -S.", "" ] ]
The $P_5'$ anomaly uncovered by the LHCb experiment in $B \to K^*\mu\mu$ angular observables has motivated a possible $Z'$ boson that couples to left-handed $b \to s$ transitions, where a model would be gauged $L_\mu - L_\tau$ symmetry, but direct search for such a $Z'$ is not promising. Less constrained is an analogous $Z'$ coupling to right-handed $t \to c$ transitions. Motivated by this, we study $cg \to tZ'$ associated production at LHC, both for a generic model, and in $L_\mu - L_\tau$ with a vector-like U quark. We also study $c\bar c \to Z'$ production that exists within the model. Both processes can be probed already with LHC Run 2 data, all the way up to the HL-LHC with discovery potential.
hep-ph/9912405
Nikolai Romanenko
K. Huitu, J. Maalampi, P. N. Pandita, K. Puolamaki, M. Raidal and N. Romanenko
Tests of the left-right electroweak model at linear collider
22 pages, 6 figures, DESY report
null
null
HIP-1999-77/TH
hep-ph
null
The left-right model is a gauge theory of electroweak interactions based on the gauge symmetry SU(2)_R . The main motivations for this model are that it gives an explanation for the parity violation of weak interactions, provides a mechanism (see-saw) for generating neutrino masses, and has B-L as a gauge symmetry. The quark-lepton symmetry in weak interactions is also maintained in this theory. The model has many predictions one can directly test at a TeV-scale linear collider. We will consider here two processes (e,e -> q, q, barQ, barQ and e,e ->mu, nu, q, barQ) testing the lepton flavour violation predicted by the model. We will also discuss constraints on supersymmetric versions of the model.
[ { "created": "Fri, 17 Dec 1999 16:45:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Huitu", "K.", "" ], [ "Maalampi", "J.", "" ], [ "Pandita", "P. N.", "" ], [ "Puolamaki", "K.", "" ], [ "Raidal", "M.", "" ], [ "Romanenko", "N.", "" ] ]
The left-right model is a gauge theory of electroweak interactions based on the gauge symmetry SU(2)_R . The main motivations for this model are that it gives an explanation for the parity violation of weak interactions, provides a mechanism (see-saw) for generating neutrino masses, and has B-L as a gauge symmetry. The quark-lepton symmetry in weak interactions is also maintained in this theory. The model has many predictions one can directly test at a TeV-scale linear collider. We will consider here two processes (e,e -> q, q, barQ, barQ and e,e ->mu, nu, q, barQ) testing the lepton flavour violation predicted by the model. We will also discuss constraints on supersymmetric versions of the model.
hep-ph/9909475
Tom Steele
Fang Shi, T.G. Steele, V.Elias, K.B. Sprague, Ying Xue, A.H. Fariborz
Hoelder Inequalities and Isospin Splitting of the Quark Scalar Mesons
28 pages, latex2e, 10 embedded eps figues. Analysis extended
Nucl.Phys.A671:416-446,2000
10.1016/S0375-9474(99)00837-4
null
hep-ph
null
A Hoelder inequality analysis of the QCD Laplace sum-rule which probes the non-strange (n\bar n) components of the I={0,1} (light-quark) scalar mesons supports the methodological consistency of an effective continuum contribution from instanton effects. This revised formulation enhances the magnitude of the instanton contributions which split the degeneracy between the I=0 and I=1 channels. Despite this enhanced isospin splitting effect, analysis of the Laplace and finite-energy sum-rules seems to preclude identification of a_0(980) and a light broad sigma-resonance state as the lightest isovector and isoscalar spin-zero $n\bar n$ mesons. This apparent decoupling of sigma [\equiv f_0(400-1200)] and a_0(980) from the quark n\bar n scalar currents suggests either a non-q \bar q or a dominantly s\bar s interpretation of these resonances, and further suggests the possible identification of the f_0(980) and a_0(1450) as the lightest I={0,1} scalar mesons containing a substantial n\bar n component.
[ { "created": "Wed, 22 Sep 1999 15:43:32 GMT", "version": "v1" }, { "created": "Fri, 14 Jan 2000 15:14:57 GMT", "version": "v2" } ]
2008-11-26
[ [ "Shi", "Fang", "" ], [ "Steele", "T. G.", "" ], [ "Elias", "V.", "" ], [ "Sprague", "K. B.", "" ], [ "Xue", "Ying", "" ], [ "Fariborz", "A. H.", "" ] ]
A Hoelder inequality analysis of the QCD Laplace sum-rule which probes the non-strange (n\bar n) components of the I={0,1} (light-quark) scalar mesons supports the methodological consistency of an effective continuum contribution from instanton effects. This revised formulation enhances the magnitude of the instanton contributions which split the degeneracy between the I=0 and I=1 channels. Despite this enhanced isospin splitting effect, analysis of the Laplace and finite-energy sum-rules seems to preclude identification of a_0(980) and a light broad sigma-resonance state as the lightest isovector and isoscalar spin-zero $n\bar n$ mesons. This apparent decoupling of sigma [\equiv f_0(400-1200)] and a_0(980) from the quark n\bar n scalar currents suggests either a non-q \bar q or a dominantly s\bar s interpretation of these resonances, and further suggests the possible identification of the f_0(980) and a_0(1450) as the lightest I={0,1} scalar mesons containing a substantial n\bar n component.
hep-ph/9209234
Zheng Huang
Zheng Huang
On the Anomalous Discrete Symmetry
10 papges in LaTeX, SFU-Preprint-92-7
Phys.Rev.D46:4818-4821,1992
10.1103/PhysRevD.46.R4818
null
hep-ph
null
We examine an interesting scenario to solve the domain wall problem recently suggested by Preskill, Trivedi, Wilczek and Wise. The effective potential is calculated in the presence of the QCD axial anomaly. It is shown that some discrete symmetries such as CP and Z_2 can be anomalous due to a so-called $K$-term induced by instantons. We point out that Z_2 domain-wall problem in the two-doublet standard model can be resolved by two types of solutions: the CP-conserving one and the CP-breaking one. In the first case, there exist two Z_2-related local minima whose energy splitting is provided by the instanton effect. In the second case, there is only one unique vacuum so that the domain walls do not form at all. The consequences of this new source of CP violation are discussed and shown to be well within the experimental limits in weak interactions.
[ { "created": "Mon, 14 Sep 1992 19:05:44 GMT", "version": "v1" } ]
2010-11-01
[ [ "Huang", "Zheng", "" ] ]
We examine an interesting scenario to solve the domain wall problem recently suggested by Preskill, Trivedi, Wilczek and Wise. The effective potential is calculated in the presence of the QCD axial anomaly. It is shown that some discrete symmetries such as CP and Z_2 can be anomalous due to a so-called $K$-term induced by instantons. We point out that Z_2 domain-wall problem in the two-doublet standard model can be resolved by two types of solutions: the CP-conserving one and the CP-breaking one. In the first case, there exist two Z_2-related local minima whose energy splitting is provided by the instanton effect. In the second case, there is only one unique vacuum so that the domain walls do not form at all. The consequences of this new source of CP violation are discussed and shown to be well within the experimental limits in weak interactions.
1501.05235
Nadezda Chernyavskaya
Alexander Bylinkin, Nadezda Chernyavskaya, Andrei Rostovtsev
Predictions on the transverse momentum spectra for charged particle production at LHC-energies from a two component model
5 pages, 7 plots
null
10.1140/epjc/s10052-015-3392-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transverse momentum spectra, $d^2\sigma/(d\eta dp_T^2)$, of charged hadron production in $pp$-collisions are considered in terms of a recently introduced two component model. The shapes of the particle distributions vary as a function of c.m.s. energy in the collision and the measured pseudorapidity interval. In order to extract predictions on the double-differential cross-sections $d^2\sigma/(d\eta dp_T^2)$ of hadron production for future LHC-measurements the different sets of available experimental data have been used in this study.
[ { "created": "Wed, 21 Jan 2015 17:19:56 GMT", "version": "v1" } ]
2015-05-20
[ [ "Bylinkin", "Alexander", "" ], [ "Chernyavskaya", "Nadezda", "" ], [ "Rostovtsev", "Andrei", "" ] ]
Transverse momentum spectra, $d^2\sigma/(d\eta dp_T^2)$, of charged hadron production in $pp$-collisions are considered in terms of a recently introduced two component model. The shapes of the particle distributions vary as a function of c.m.s. energy in the collision and the measured pseudorapidity interval. In order to extract predictions on the double-differential cross-sections $d^2\sigma/(d\eta dp_T^2)$ of hadron production for future LHC-measurements the different sets of available experimental data have been used in this study.
hep-ph/0505022
Mikhail Gorshteyn
M. Gorchtein
Beam normal spin asymmetry in the equivalent photon approximation
10 pages, 5 figures; revtex
null
null
null
hep-ph nucl-th
null
The two-photon exchange contribution to the single spin asymmetries with the spin orientation normal to the reaction plane is discussed for elastic electron-proton scattering in Regge regime. For this, the equivalent photon approximation is adopted. In this case, hadronic part of the two-photon exchange amplitude describes real Compton scattering (RCS). The imaginary part of helicity conserving RCS amplitudes are related to total photoabsorption cross section. The contribution of the photon helicity flipping amplitudes is estimated by the two pion exchange in the $t$-channel. We observe the double logarithmic enhancement in the electron mass but find it's contribution to the asymmetry negligibly small in the forward kinematics. These results are in strong disagreement with the existing calculation.
[ { "created": "Tue, 3 May 2005 19:54:59 GMT", "version": "v1" }, { "created": "Tue, 3 May 2005 20:02:07 GMT", "version": "v2" }, { "created": "Tue, 10 May 2005 19:11:08 GMT", "version": "v3" } ]
2015-07-22
[ [ "Gorchtein", "M.", "" ] ]
The two-photon exchange contribution to the single spin asymmetries with the spin orientation normal to the reaction plane is discussed for elastic electron-proton scattering in Regge regime. For this, the equivalent photon approximation is adopted. In this case, hadronic part of the two-photon exchange amplitude describes real Compton scattering (RCS). The imaginary part of helicity conserving RCS amplitudes are related to total photoabsorption cross section. The contribution of the photon helicity flipping amplitudes is estimated by the two pion exchange in the $t$-channel. We observe the double logarithmic enhancement in the electron mass but find it's contribution to the asymmetry negligibly small in the forward kinematics. These results are in strong disagreement with the existing calculation.
hep-ph/0509318
Kamalov Sabit
S. N. Yang (Department of Physics, NTU, Taipei, Taiwan), S. S. Kamalov (Laboratory of Theoretical Physics, JINR, Dubna, Russia)
Dynamical study of $\gamma^*N \leftrightarrow \Delta$ transition with $N(e,e'p)\pi$
4 pages, 2 postscript figures, contr. to Int. Conf. on QCD and Hadronic Physics, Beijing from Jun 16-20, 2005
Int.J.Mod.Phys. A21 (2006) 873-876
10.1142/S0217751X06032204
null
hep-ph
null
The Dubna-Mainz-Taipei (DMT) dynamical model for pion electromagnetic production, which describe well the existing data from threshold up to 1 GeV photon lab energy is presented and used to analyze recent data in the $\Delta$ region . We find that within DMT model, the bare $\Delta$ is almost spherical while the physical $\Delta$ is oblate. The deformation is almost saturated by the pion cloud effects.
[ { "created": "Wed, 28 Sep 2005 07:47:25 GMT", "version": "v1" } ]
2016-09-06
[ [ "Yang", "S. N.", "", "Department of Physics, NTU, Taipei, Taiwan" ], [ "Kamalov", "S. S.", "", "Laboratory of Theoretical Physics, JINR, Dubna, Russia" ] ]
The Dubna-Mainz-Taipei (DMT) dynamical model for pion electromagnetic production, which describe well the existing data from threshold up to 1 GeV photon lab energy is presented and used to analyze recent data in the $\Delta$ region . We find that within DMT model, the bare $\Delta$ is almost spherical while the physical $\Delta$ is oblate. The deformation is almost saturated by the pion cloud effects.
2011.02171
Hiranmaya Mishra
Guruprasad Kadam, Hiranmaya Mishra, Marco Panero
Critical exponents and transport properties near the QCD critical endpoint from the statistical bootstrap model
21 pages, 6 figures. Published version
Eur. Phys. J. C 81 (2021) 9, 795
10.1140/epjc/s10052-021-09596-6
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an estimate of the behaviour of the shear and bulk viscosity coefficients when the QCD critical point is approached from the hadronic side, describing hadronic matter within the statistical bootstrap model (SBM) of strong interactions. The boostrap model shows critical behavior near the quark-hadron transition temperature if the parameter characterizing the degeneracy of Hagedorn states is properly chosen. We calculate the critical exponents and amplitudes of relevant thermodynamic quantities near the QCD critical point and combine them with an Ansatz for the shear and bulk viscosity coefficients to derive the behavior of these coefficients near the critical point. The shear viscosity to entropy density ratio is found to decrease when the temperature is increased, and to approach the Kovtun-Son-Starinets bound 1/(4{\pi}) faster near the critical point, while the bulk viscosity coefficient is found to rise very rapidly.
[ { "created": "Wed, 4 Nov 2020 08:20:47 GMT", "version": "v1" }, { "created": "Tue, 12 Oct 2021 05:36:06 GMT", "version": "v2" } ]
2021-10-14
[ [ "Kadam", "Guruprasad", "" ], [ "Mishra", "Hiranmaya", "" ], [ "Panero", "Marco", "" ] ]
We present an estimate of the behaviour of the shear and bulk viscosity coefficients when the QCD critical point is approached from the hadronic side, describing hadronic matter within the statistical bootstrap model (SBM) of strong interactions. The boostrap model shows critical behavior near the quark-hadron transition temperature if the parameter characterizing the degeneracy of Hagedorn states is properly chosen. We calculate the critical exponents and amplitudes of relevant thermodynamic quantities near the QCD critical point and combine them with an Ansatz for the shear and bulk viscosity coefficients to derive the behavior of these coefficients near the critical point. The shear viscosity to entropy density ratio is found to decrease when the temperature is increased, and to approach the Kovtun-Son-Starinets bound 1/(4{\pi}) faster near the critical point, while the bulk viscosity coefficient is found to rise very rapidly.
1405.7583
Alberto Mart\'inez Torres
A. Martinez Torres, K. P. Khemchandani, F. S. Navarra, M. Nielsen, Luciano M. Abreu
On $X(3872)$ production in high energy heavy ion collisions
null
Phys. Rev. D 90, 114023 (2014)
10.1103/PhysRevD.90.114023
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have determined the production cross sections of the $X(3872)$ state in the reactions $\bar D D\to\pi X$, $\bar D^* D\to \pi X$ and $\bar D^* D^*\to\pi X$, information which is useful for studies of the $X(3872)$ meson abundance in heavy ion collisions. We construct a formalism considering $X$ as a molecular bound state of $\bar D^0 D^{*0} - \textrm{c.c}$, $D^- D^{*+} - \textrm{c.c}$ and $D^-_s D^{*+}_s - \textrm{c.c}$. To obtain the amplitudes related to these processes we have made use of effective field Lagrangians. The evaluation of the cross section of the processes involving $D^*$ meson(s) requires the calculation of an anomalous vertex, $X\bar D^* D^*$, which has been obtained by considering triangular loops motivated by the molecular nature of $X(3872)$. Proceeding in this way, we have evaluated the cross section for the reaction $\bar D^* D\to \pi X$, and find that the diagrams involving the $X\bar D^* D^*$ vertex give a large contribution. Encouraged by this finding we estimate the $X\bar D^* D^*$ coupling, which turns out to be $1.95\pm 0.22$. We then use it to obtain the cross section for the reaction $\bar D^* D^*\to\pi X$ and find that, in this case too, the $X\bar D^* D^*$ vertex is relevant. We also discuss the role of the charged components of $X$ in the determination of the production cross sections.
[ { "created": "Thu, 29 May 2014 15:08:11 GMT", "version": "v1" } ]
2014-12-24
[ [ "Torres", "A. Martinez", "" ], [ "Khemchandani", "K. P.", "" ], [ "Navarra", "F. S.", "" ], [ "Nielsen", "M.", "" ], [ "Abreu", "Luciano M.", "" ] ]
We have determined the production cross sections of the $X(3872)$ state in the reactions $\bar D D\to\pi X$, $\bar D^* D\to \pi X$ and $\bar D^* D^*\to\pi X$, information which is useful for studies of the $X(3872)$ meson abundance in heavy ion collisions. We construct a formalism considering $X$ as a molecular bound state of $\bar D^0 D^{*0} - \textrm{c.c}$, $D^- D^{*+} - \textrm{c.c}$ and $D^-_s D^{*+}_s - \textrm{c.c}$. To obtain the amplitudes related to these processes we have made use of effective field Lagrangians. The evaluation of the cross section of the processes involving $D^*$ meson(s) requires the calculation of an anomalous vertex, $X\bar D^* D^*$, which has been obtained by considering triangular loops motivated by the molecular nature of $X(3872)$. Proceeding in this way, we have evaluated the cross section for the reaction $\bar D^* D\to \pi X$, and find that the diagrams involving the $X\bar D^* D^*$ vertex give a large contribution. Encouraged by this finding we estimate the $X\bar D^* D^*$ coupling, which turns out to be $1.95\pm 0.22$. We then use it to obtain the cross section for the reaction $\bar D^* D^*\to\pi X$ and find that, in this case too, the $X\bar D^* D^*$ vertex is relevant. We also discuss the role of the charged components of $X$ in the determination of the production cross sections.
0706.1281
Nausheen Shah
Anibal D. Medina, Nausheen R. Shah and Carlos E. M. Wagner
Gauge-Higgs Unification and Radiative Electroweak Symmetry Breaking in Warped Extra Dimensions
31 pages, 9 figures. Corrected typo in boundary condition for gauge bosons and top mass equation. To appear in PRD
Phys.Rev.D76:095010,2007
10.1103/PhysRevD.76.095010
null
hep-ph hep-ex hep-th
null
We compute the Coleman Weinberg effective potential for the Higgs field in RS Gauge-Higgs unification scenarios based on a bulk SO(5) x U(1)_X gauge symmetry, with gauge and fermion fields propagating in the bulk and a custodial symmetry protecting the generation of large corrections to the T parameter and the coupling of the Z to the bottom quark. We demonstrate that electroweak symmetry breaking may be realized, with proper generation of the top and bottom quark masses for the same region of bulk mass parameters that lead to good agreement with precision electroweak data in the presence of a light Higgs. We compute the Higgs mass and demonstrate that for the range of parameters for which the Higgs boson has Standard Model-like properties, the Higgs mass is naturally in a range that varies between values close to the LEP experimental limit and about 160 GeV. This mass range may be probed at the Tevatron and at the LHC. We analyze the KK spectrum and briefly discuss the phenomenology of the light resonances arising in our model.
[ { "created": "Sat, 9 Jun 2007 02:11:56 GMT", "version": "v1" }, { "created": "Tue, 11 Sep 2007 14:13:09 GMT", "version": "v2" } ]
2008-11-26
[ [ "Medina", "Anibal D.", "" ], [ "Shah", "Nausheen R.", "" ], [ "Wagner", "Carlos E. M.", "" ] ]
We compute the Coleman Weinberg effective potential for the Higgs field in RS Gauge-Higgs unification scenarios based on a bulk SO(5) x U(1)_X gauge symmetry, with gauge and fermion fields propagating in the bulk and a custodial symmetry protecting the generation of large corrections to the T parameter and the coupling of the Z to the bottom quark. We demonstrate that electroweak symmetry breaking may be realized, with proper generation of the top and bottom quark masses for the same region of bulk mass parameters that lead to good agreement with precision electroweak data in the presence of a light Higgs. We compute the Higgs mass and demonstrate that for the range of parameters for which the Higgs boson has Standard Model-like properties, the Higgs mass is naturally in a range that varies between values close to the LEP experimental limit and about 160 GeV. This mass range may be probed at the Tevatron and at the LHC. We analyze the KK spectrum and briefly discuss the phenomenology of the light resonances arising in our model.
hep-ph/9608490
Stephen Hsu
N. Evans, S.D.H. Hsu, A. Nyffeler and M. Schwetz (Yale University)
QCD at Large $\theta$ Angle and Axion Cosmology
12 pages, LaTeX, 5 epsf figures
Nucl.Phys. B494 (1997) 200-212
10.1016/S0550-3213(97)00174-0
YCTP-P14-96
hep-ph hep-th
null
We use the chiral Lagrangian to investigate the global properties of the $N$-flavor QCD vacuum as a function of the $\theta$ parameter. In the case of exact quark degeneracy we find evidence for first order phase transitions at $\theta = \pi \cdot ({\rm odd~ integer})$. The first order transitions are smoothed by quark mass splittings, although interesting effects remain at realistic quark masses. We emphasize the role of the $\eta'$ condensate in our analysis. Finally, we discuss the implications of our results on the internal hadronic structure of axion domain walls and axion cosmology.
[ { "created": "Thu, 29 Aug 1996 18:14:00 GMT", "version": "v1" } ]
2009-10-28
[ [ "Evans", "N.", "", "Yale University" ], [ "Hsu", "S. D. H.", "", "Yale University" ], [ "Nyffeler", "A.", "", "Yale University" ], [ "Schwetz", "M.", "", "Yale University" ] ]
We use the chiral Lagrangian to investigate the global properties of the $N$-flavor QCD vacuum as a function of the $\theta$ parameter. In the case of exact quark degeneracy we find evidence for first order phase transitions at $\theta = \pi \cdot ({\rm odd~ integer})$. The first order transitions are smoothed by quark mass splittings, although interesting effects remain at realistic quark masses. We emphasize the role of the $\eta'$ condensate in our analysis. Finally, we discuss the implications of our results on the internal hadronic structure of axion domain walls and axion cosmology.
1612.07967
Ulrich Nierste
Teppei Kitahara, Ulrich Nierste, and Paul Tremper
Direct CP violation in $K\to \pi \pi$ decays and supersymmetry
Talk at ICHEP 2016, Chicago
null
null
TTP16-059
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quantities $\epsilon_K^\prime$ and $\epsilon_K$ measure the amount of direct and indirect CP violation in $K\to \pi\pi$ decays, respectively. Using the recent lattice results from the RBC and UKQCD Collaborations and a new compact implementation of the $\Delta S=1$ renormalization group evolution we predict $ \mbox{Re}\, \frac{\epsilon_{K}'}{\epsilon_{K}} = \left(1.06 \pm 5.07 \right) \times 10^{-4}$ in the Standard Model. This value is $2.8\,\sigma$ below the experimental value of $ \mbox{Re}\, \frac{\epsilon_{K}'}{\epsilon_{K}} = \left(16.6 \pm 2.3 \right) \times 10^{-4}.$ In generic models of new physics the well-understood $\epsilon_K$ precludes large contributions to $\epsilon_K^\prime$, if the new contributions enter at loop level. However, one can resolve the tension in $\epsilon_{K}'/\epsilon_{K}$ within the Minimal Supersymmetric Standard Model. To this end two features of supersymmetry are crucial: First, one can have large isospin-breaking contributions (involving the strong instead of the weak interaction) which enhance $\epsilon_K^\prime$. Second, the Majorana nature of gluinos permits a suppression of the MSSM contribution to $\epsilon_K$, because two box diagrams interfere destructively.
[ { "created": "Fri, 23 Dec 2016 13:41:48 GMT", "version": "v1" } ]
2016-12-26
[ [ "Kitahara", "Teppei", "" ], [ "Nierste", "Ulrich", "" ], [ "Tremper", "Paul", "" ] ]
The quantities $\epsilon_K^\prime$ and $\epsilon_K$ measure the amount of direct and indirect CP violation in $K\to \pi\pi$ decays, respectively. Using the recent lattice results from the RBC and UKQCD Collaborations and a new compact implementation of the $\Delta S=1$ renormalization group evolution we predict $ \mbox{Re}\, \frac{\epsilon_{K}'}{\epsilon_{K}} = \left(1.06 \pm 5.07 \right) \times 10^{-4}$ in the Standard Model. This value is $2.8\,\sigma$ below the experimental value of $ \mbox{Re}\, \frac{\epsilon_{K}'}{\epsilon_{K}} = \left(16.6 \pm 2.3 \right) \times 10^{-4}.$ In generic models of new physics the well-understood $\epsilon_K$ precludes large contributions to $\epsilon_K^\prime$, if the new contributions enter at loop level. However, one can resolve the tension in $\epsilon_{K}'/\epsilon_{K}$ within the Minimal Supersymmetric Standard Model. To this end two features of supersymmetry are crucial: First, one can have large isospin-breaking contributions (involving the strong instead of the weak interaction) which enhance $\epsilon_K^\prime$. Second, the Majorana nature of gluinos permits a suppression of the MSSM contribution to $\epsilon_K$, because two box diagrams interfere destructively.
hep-ph/0009120
Jeroen Vink
M. Salle, J. Smit, J.C. Vink
Scalar Field Dynamics: Classical, Quantum and in Between
Presented at SEWM 2000, 6 pages including figures, reference corrected
null
10.1142/9789812799913_0042
null
hep-ph
null
Using a Hartree ensemble approximation, we investigate the dynamics of the \f^4 model in 1+1 dimensions. We find that the fields initially thermalize with a Bose-Einstein distribution for the fields. Gradually, however, the distribution changes towards classical equipartition. Using suitable initial conditions quantum thermalization is achieved much faster than the onset of this undesirable equipartition. We also show how the numerical efficiency of our method can be significantly improved.
[ { "created": "Mon, 11 Sep 2000 12:40:53 GMT", "version": "v1" }, { "created": "Tue, 3 Oct 2000 07:08:11 GMT", "version": "v2" } ]
2017-08-23
[ [ "Salle", "M.", "" ], [ "Smit", "J.", "" ], [ "Vink", "J. C.", "" ] ]
Using a Hartree ensemble approximation, we investigate the dynamics of the \f^4 model in 1+1 dimensions. We find that the fields initially thermalize with a Bose-Einstein distribution for the fields. Gradually, however, the distribution changes towards classical equipartition. Using suitable initial conditions quantum thermalization is achieved much faster than the onset of this undesirable equipartition. We also show how the numerical efficiency of our method can be significantly improved.
2008.10568
Noah Steinberg
Benjamin Sheff, Noah Steinberg, James D. Wells
Higgs boson decays into narrow di-photon jets and their search strategies at the Large Hadron Collider
18 pages, 6 figures
Phys. Rev. D 104, 036009 (2021)
10.1103/PhysRevD.104.036009
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many extensions of the Standard Model the Higgs boson can decay into two light scalars each of which then subsequently decay into two photons. The underlying event is h $\to$ 4$\gamma$, but the kinematics from boosted light scalar decays combined with realistic detector resolutions may fail to register the events in straightforward categories and thus may be lost. In this article we investigate the phase space for highly boosted di-photon events from these exotic Higgs decays and discuss search strategies that aim to capture and label events in this difficult region. In the process we develop a new category, $\xi$-jets, which identifies with high selectivity highly collimated di-photon decay modes of the Higgs boson.
[ { "created": "Mon, 24 Aug 2020 17:15:03 GMT", "version": "v1" } ]
2021-09-01
[ [ "Sheff", "Benjamin", "" ], [ "Steinberg", "Noah", "" ], [ "Wells", "James D.", "" ] ]
In many extensions of the Standard Model the Higgs boson can decay into two light scalars each of which then subsequently decay into two photons. The underlying event is h $\to$ 4$\gamma$, but the kinematics from boosted light scalar decays combined with realistic detector resolutions may fail to register the events in straightforward categories and thus may be lost. In this article we investigate the phase space for highly boosted di-photon events from these exotic Higgs decays and discuss search strategies that aim to capture and label events in this difficult region. In the process we develop a new category, $\xi$-jets, which identifies with high selectivity highly collimated di-photon decay modes of the Higgs boson.
0804.2867
Yin Lin
Yin Lin
A predictive A4 model, Charged Lepton Hierarchy and Tri-bimaximal Sum Rule
15 pages, minor changes and some typos corrected
null
10.1016/j.nuclphysb.2008.12.025
DFPD-08/TH/04
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel A4 model in which the Tri-Bimaximal (TB) neutrino mixing and the charged lepton mass hierarchy are reproduced simultaneously. At leading order, the residual symmetry of the neutrino sector is Z2 x Z2 which guarantees the TB mixing without adjusting ad hoc free parameters. In the charged lepton sector, one of the previous Z2 is maximally broken and the resulting mass matrix is nearly diagonal and hierarchical. A natural mechanism for the required vacuum alignment is given with the help of the supersymmetry and an abelian symmetry factor. In our model, subleading effects which could lead to appreciable deviations from TB mixing are very restrictive giving rise to possible next-to-leading predictions. From an explicit example, we show that our ``constrained'' A4 model is a natural framework, based on symmetry principle, to incorporate the TB sum rule: sin^2(\theta_{12})=1/3+2\sqrt{2}(cos(\delta) sin(\theta_{13})/3).
[ { "created": "Thu, 17 Apr 2008 18:19:38 GMT", "version": "v1" }, { "created": "Tue, 20 May 2008 18:36:41 GMT", "version": "v2" } ]
2009-11-13
[ [ "Lin", "Yin", "" ] ]
We propose a novel A4 model in which the Tri-Bimaximal (TB) neutrino mixing and the charged lepton mass hierarchy are reproduced simultaneously. At leading order, the residual symmetry of the neutrino sector is Z2 x Z2 which guarantees the TB mixing without adjusting ad hoc free parameters. In the charged lepton sector, one of the previous Z2 is maximally broken and the resulting mass matrix is nearly diagonal and hierarchical. A natural mechanism for the required vacuum alignment is given with the help of the supersymmetry and an abelian symmetry factor. In our model, subleading effects which could lead to appreciable deviations from TB mixing are very restrictive giving rise to possible next-to-leading predictions. From an explicit example, we show that our ``constrained'' A4 model is a natural framework, based on symmetry principle, to incorporate the TB sum rule: sin^2(\theta_{12})=1/3+2\sqrt{2}(cos(\delta) sin(\theta_{13})/3).
1003.4497
Douglas Higinbotham
D. W. Higinbotham, J. Gomez, E. Piasetzky
Nuclear Scaling and the EMC Effect
14 pages, 3 figures, 1 table
null
null
JLAB-PHY-10-1158
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Results of recent EMC effect measurements and nuclear scaling measurements have both been attributed to local nuclear density effects and not properties of the bulk nuclear system. This lead us to the phenomenological observation that the ratio of the slopes in the 0.3 < x_B < 0.7 EMC data scale as the ratio of the x_B > 1 nuclear scaling plateaus. Using this correlation, we developed a phenomenological relation which reproduces the general trends and features of the EMC effect for nuclei from 3He to 56Fe.
[ { "created": "Tue, 23 Mar 2010 19:39:33 GMT", "version": "v1" }, { "created": "Mon, 20 Sep 2010 12:12:10 GMT", "version": "v2" } ]
2010-09-21
[ [ "Higinbotham", "D. W.", "" ], [ "Gomez", "J.", "" ], [ "Piasetzky", "E.", "" ] ]
Results of recent EMC effect measurements and nuclear scaling measurements have both been attributed to local nuclear density effects and not properties of the bulk nuclear system. This lead us to the phenomenological observation that the ratio of the slopes in the 0.3 < x_B < 0.7 EMC data scale as the ratio of the x_B > 1 nuclear scaling plateaus. Using this correlation, we developed a phenomenological relation which reproduces the general trends and features of the EMC effect for nuclei from 3He to 56Fe.
2212.02949
Supriya Pan
Animesh Chatterjee, Srubabati Goswami, Supriya Pan
Matter effect in presence of a sterile neutrino and resolution of the octant degeneracy using a liquid argon detector
25 pages, 18 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Results from the experiments like LSND, and MiniBooNE hint towards the possible presence of an extra eV scale sterile neutrino. The addition of such a neutrino will significantly impact the standard three flavour neutrino oscillations; in particular, it can give rise to additional degeneracies due to new sterile parameters. In our work, we investigate how the sensitivity to determine the octant of the neutrino mixing angle $\theta_{23}$ is affected by introducing a sterile neutrino to the standard neutrino oscillation framework. We compute the oscillation probabilities in presence of a sterile neutrino, analytically, using the approximation that $\Delta_{21}$, the smallest mass squared difference, is zero. We use these probabilities to understand the degeneracies analytically at different baselines. We present our results of the sensitivity to octant of $\theta_{23}$ for beam neutrinos using a liquid argon time projection chamber (LArTPC). We also obtain octant sensitivity using atmospheric neutrinos using the same LArTPC detector without any charge identification capability. In addition, we include the charge tagging capability of muon capture in argon which allows one to differentiate between muon neutrino and antineutrino events. The combined sensitivity of beam and atmospheric neutrinos in a similar experimental setup is also delineated. We observe that by combining simulated data from the beam and atmospheric neutrinos (including charge-id for muons), the sensitivity to the octant of $\theta_{23}$ for true values of $\theta_{23}=41^\circ(49^\circ)$ exceeds $4\sigma(3\sigma)$ for more than $50\%$ values of true $\delta_{13}$.
[ { "created": "Tue, 6 Dec 2022 13:07:56 GMT", "version": "v1" }, { "created": "Thu, 12 Jan 2023 13:56:26 GMT", "version": "v2" }, { "created": "Tue, 17 Oct 2023 09:43:25 GMT", "version": "v3" } ]
2023-10-18
[ [ "Chatterjee", "Animesh", "" ], [ "Goswami", "Srubabati", "" ], [ "Pan", "Supriya", "" ] ]
Results from the experiments like LSND, and MiniBooNE hint towards the possible presence of an extra eV scale sterile neutrino. The addition of such a neutrino will significantly impact the standard three flavour neutrino oscillations; in particular, it can give rise to additional degeneracies due to new sterile parameters. In our work, we investigate how the sensitivity to determine the octant of the neutrino mixing angle $\theta_{23}$ is affected by introducing a sterile neutrino to the standard neutrino oscillation framework. We compute the oscillation probabilities in presence of a sterile neutrino, analytically, using the approximation that $\Delta_{21}$, the smallest mass squared difference, is zero. We use these probabilities to understand the degeneracies analytically at different baselines. We present our results of the sensitivity to octant of $\theta_{23}$ for beam neutrinos using a liquid argon time projection chamber (LArTPC). We also obtain octant sensitivity using atmospheric neutrinos using the same LArTPC detector without any charge identification capability. In addition, we include the charge tagging capability of muon capture in argon which allows one to differentiate between muon neutrino and antineutrino events. The combined sensitivity of beam and atmospheric neutrinos in a similar experimental setup is also delineated. We observe that by combining simulated data from the beam and atmospheric neutrinos (including charge-id for muons), the sensitivity to the octant of $\theta_{23}$ for true values of $\theta_{23}=41^\circ(49^\circ)$ exceeds $4\sigma(3\sigma)$ for more than $50\%$ values of true $\delta_{13}$.
1605.05328
Michele Lucente
Michele Lucente, Asmaa Abada, Giorgio Arcadi and Valerie Domcke
Lepton number symmetry as a way to testable leptogenesis
8 pages, 4 figures. To appear in the proceedings of the 51st Rencontres de Moriond EW 2016, 12-19 March 2016 in La Thuile, Italy. v2: discussion on thermal leptogenesis extended, references added
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a minimal and motivated extension of the Standard Model characterised by an approximate lepton number conservation, which is able to simultaneously generate neutrino masses and to account for a successful baryogenesis via leptogenesis. The sterile fermions involved in the leptogenesis process have masses at the GeV scale. We determine the viable parameter space that complies with both the neutrino and baryogenesis phenomenology, and analyse the different regimes for the generation of a lepton asymmetry in the early Universe (weak and strong-washout) in order to determine their testability in future experimental facilities.
[ { "created": "Tue, 17 May 2016 20:00:02 GMT", "version": "v1" }, { "created": "Tue, 23 Aug 2016 14:42:00 GMT", "version": "v2" } ]
2016-08-24
[ [ "Lucente", "Michele", "" ], [ "Abada", "Asmaa", "" ], [ "Arcadi", "Giorgio", "" ], [ "Domcke", "Valerie", "" ] ]
We propose a minimal and motivated extension of the Standard Model characterised by an approximate lepton number conservation, which is able to simultaneously generate neutrino masses and to account for a successful baryogenesis via leptogenesis. The sterile fermions involved in the leptogenesis process have masses at the GeV scale. We determine the viable parameter space that complies with both the neutrino and baryogenesis phenomenology, and analyse the different regimes for the generation of a lepton asymmetry in the early Universe (weak and strong-washout) in order to determine their testability in future experimental facilities.
1911.08502
Anton Chudaykin A. S.
F. Bezrukov, A. Chudaykin, D. Gorbunov
Scalar induced resonant sterile neutrino production in the early Universe
v1: 29 pages, 6 figures. v2: a clear explanation of differences and improvements with respect to previous works is added, published version
Phys. Rev. D 101, 103516 (2020)
10.1103/PhysRevD.101.103516
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been recently suggested \cite{Bezrukov:2017ike,Bezrukov:2018wvd} that a cosmic scalar field can completely change the keV-scale sterile neutrino production in the early Universe. Its effect may, for various parameter choices, either suppress sterile neutrino production and make moderate active-sterile mixing cosmologically acceptable, or increase the production and generate considerable dark matter component out of sterile neutrino with otherwise negligible mixing with SM. In this paper we provide analytic estimates complementing and providing details of the numerical calculations performed in \cite{Bezrukov:2018wvd} in the case of resonant amplification of the sterile neutrino production. We also discuss phenomenological and theoretical issues related to the successful implementation of this idea in fully realistic extensions of the Standard Model of particle physics.
[ { "created": "Tue, 19 Nov 2019 19:00:35 GMT", "version": "v1" }, { "created": "Mon, 13 Jul 2020 10:40:10 GMT", "version": "v2" } ]
2020-07-14
[ [ "Bezrukov", "F.", "" ], [ "Chudaykin", "A.", "" ], [ "Gorbunov", "D.", "" ] ]
It has been recently suggested \cite{Bezrukov:2017ike,Bezrukov:2018wvd} that a cosmic scalar field can completely change the keV-scale sterile neutrino production in the early Universe. Its effect may, for various parameter choices, either suppress sterile neutrino production and make moderate active-sterile mixing cosmologically acceptable, or increase the production and generate considerable dark matter component out of sterile neutrino with otherwise negligible mixing with SM. In this paper we provide analytic estimates complementing and providing details of the numerical calculations performed in \cite{Bezrukov:2018wvd} in the case of resonant amplification of the sterile neutrino production. We also discuss phenomenological and theoretical issues related to the successful implementation of this idea in fully realistic extensions of the Standard Model of particle physics.
1606.09621
Yotam Soreq
Yotam Soreq, Hua Xing Zhu, Jure Zupan
Light quark Yukawa couplings from Higgs kinematics
15 pages, 7 figures; v2: add clarifications, plot and refs. conclusion unchanged; v3: matched to the published version
null
10.1007/JHEP12(2016)045
MIT-CTP/4817
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the normalized Higgs production $p_T$ and $y_h$ distributions are sensitive probes of Higgs couplings to light quarks. For up and/or down quark Yukawa couplings comparable to the SM $b$ quark Yukawa the $\bar u u$ or $\bar d d$ fusion production of the Higgs could lead to appreciable softer $p_T$ distribution than in the SM. The rapidity distribution, on the other hand, becomes more forward. We find that, owing partially to a downward fluctuation, one can derive competitive bounds on the two couplings using ATLAS measurements of normalized $p_T$ distribution at 8\,TeV. With 300 fb${}^{-1}$ at 13\,TeV LHC one could establish flavor non-universality of the Yukawa couplings in the down sector.
[ { "created": "Thu, 30 Jun 2016 19:20:05 GMT", "version": "v1" }, { "created": "Tue, 16 Aug 2016 11:51:57 GMT", "version": "v2" }, { "created": "Wed, 21 Dec 2016 15:44:54 GMT", "version": "v3" } ]
2017-02-01
[ [ "Soreq", "Yotam", "" ], [ "Zhu", "Hua Xing", "" ], [ "Zupan", "Jure", "" ] ]
We show that the normalized Higgs production $p_T$ and $y_h$ distributions are sensitive probes of Higgs couplings to light quarks. For up and/or down quark Yukawa couplings comparable to the SM $b$ quark Yukawa the $\bar u u$ or $\bar d d$ fusion production of the Higgs could lead to appreciable softer $p_T$ distribution than in the SM. The rapidity distribution, on the other hand, becomes more forward. We find that, owing partially to a downward fluctuation, one can derive competitive bounds on the two couplings using ATLAS measurements of normalized $p_T$ distribution at 8\,TeV. With 300 fb${}^{-1}$ at 13\,TeV LHC one could establish flavor non-universality of the Yukawa couplings in the down sector.
hep-ph/0004242
Yi Jiang
Zhou Fei, Ma Wen-Gan, Jiang Yi and Han Liang
Pair production of neutralinos via photon-photon collisions
LaTex File, 3 EPS Files, 17 pages
null
10.1103/PhysRevD.62.115006
null
hep-ph
null
We investigated the production of neutralino pairs via photon-photon collisions in the minimal supersymmetric model(MSSM) at future linear colliders. The numerical analysis of their production rates is carried out in the mSUGRA scenario. The results show that this cross section can reach about 18 femto barn for $\tilde{\chi}^{0}_{1} \tilde{\chi}^{0}_{2}$ pair production and 9 femto barn for $\tilde{\chi}^{0}_{2}\tilde{\chi}^{0}_{2}$ pair production with our chosen input parameters.
[ { "created": "Thu, 27 Apr 2000 08:47:53 GMT", "version": "v1" }, { "created": "Thu, 7 Dec 2000 08:40:49 GMT", "version": "v2" } ]
2009-10-31
[ [ "Fei", "Zhou", "" ], [ "Wen-Gan", "Ma", "" ], [ "Yi", "Jiang", "" ], [ "Liang", "Han", "" ] ]
We investigated the production of neutralino pairs via photon-photon collisions in the minimal supersymmetric model(MSSM) at future linear colliders. The numerical analysis of their production rates is carried out in the mSUGRA scenario. The results show that this cross section can reach about 18 femto barn for $\tilde{\chi}^{0}_{1} \tilde{\chi}^{0}_{2}$ pair production and 9 femto barn for $\tilde{\chi}^{0}_{2}\tilde{\chi}^{0}_{2}$ pair production with our chosen input parameters.
hep-ph/0701097
Thorsten Renk
Thorsten Renk, Kari J. Eskola
Angular hadron correlations probing the early medium evolution
Talk given at the 19th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions: Quark Matter 2006 (QM 2006), Shanghai, China, 14-20 Nov 2006
J.Phys.G34:S663-666,2007
10.1088/0954-3899/34/8/S68
null
hep-ph
null
Hard processes are a well calibrated probe to study heavy-ion collisions. However, the information to be gained from the nuclear suppression factor R_AA is limited, hene one has to study more differential observables to do medium tomography. The angular correlations of hadrons associated with a hard trigger appear suitable as they show a rich pattern when going from low p_T to high p_T. Of prime interest is the fate of away side partons with an in-medium pathlength O(several fm). At high p_T the correlations become dominated by the punchtrough of the away side parton with subsequent fragmentation. We discuss what information about the medium density can be gained from the data.
[ { "created": "Fri, 12 Jan 2007 13:05:33 GMT", "version": "v1" } ]
2008-11-26
[ [ "Renk", "Thorsten", "" ], [ "Eskola", "Kari J.", "" ] ]
Hard processes are a well calibrated probe to study heavy-ion collisions. However, the information to be gained from the nuclear suppression factor R_AA is limited, hene one has to study more differential observables to do medium tomography. The angular correlations of hadrons associated with a hard trigger appear suitable as they show a rich pattern when going from low p_T to high p_T. Of prime interest is the fate of away side partons with an in-medium pathlength O(several fm). At high p_T the correlations become dominated by the punchtrough of the away side parton with subsequent fragmentation. We discuss what information about the medium density can be gained from the data.
hep-ph/0205064
Elizabeth H. Simmons
R.S. Chivukula and E.H. Simmons
Electroweak Limits on Non-Universal Z' Bosons
17 pages, 5 figures; added references; updated figures
Phys.Rev.D66:015006,2002
10.1103/PhysRevD.66.015006
BUHEP-02-16, HUPT-02/A002
hep-ph hep-ex
null
Many types of physics beyond the standard model include an extended electroweak gauge group. If these extensions are associated with flavor symmetry breaking, the gauge interactions will not be flavor-universal. In this note we update the bounds placed by electroweak data on the existence of flavor non-universal extensions to the standard model in the context of topcolor assisted technicolor (TC2), noncommuting extended technicolor (NCETC), and the ununified standard model (UUM). In the first two cases the extended gauge interactions couple to the third generation fermions differently than to the light fermions, while in the ununified standard model the gauge interactions couple differently to quarks and leptons. The extra SU(2) triplet of gauge bosons in NCETC and UUM models must be heavier than about 3 TeV, while the extra Z boson in TC2 models must be heavier than about 1 TeV.
[ { "created": "Tue, 7 May 2002 16:09:35 GMT", "version": "v1" }, { "created": "Wed, 22 May 2002 20:30:59 GMT", "version": "v2" }, { "created": "Wed, 5 Jun 2002 13:58:42 GMT", "version": "v3" } ]
2008-11-26
[ [ "Chivukula", "R. S.", "" ], [ "Simmons", "E. H.", "" ] ]
Many types of physics beyond the standard model include an extended electroweak gauge group. If these extensions are associated with flavor symmetry breaking, the gauge interactions will not be flavor-universal. In this note we update the bounds placed by electroweak data on the existence of flavor non-universal extensions to the standard model in the context of topcolor assisted technicolor (TC2), noncommuting extended technicolor (NCETC), and the ununified standard model (UUM). In the first two cases the extended gauge interactions couple to the third generation fermions differently than to the light fermions, while in the ununified standard model the gauge interactions couple differently to quarks and leptons. The extra SU(2) triplet of gauge bosons in NCETC and UUM models must be heavier than about 3 TeV, while the extra Z boson in TC2 models must be heavier than about 1 TeV.
2002.01829
Josip Trampetic Dr.
Raul Horvat, Dusko Latas, Josip Trampetic and Jiangyang You
Light-by-Light Scattering and Spacetime Noncommutativity
8 pages, 3 figures, version to be published in PRD
null
10.1103/PhysRevD.101.095035
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aim of this article is to explore a potential usability of a photon-photon self-interaction from the noncommutative quantum electrodynamics (NCQED) in the case of light-by-light scattering ($\gamma\gamma\to\gamma\gamma$) in ultraperipheral Pb+Pb collisions, a reaction measured recently by ATLAS and planned for future experiments in hadron-hadron colliders. We compute the total cross section from both, the full one-loop standard model (SM) and the tree-level NCQED amplitudes, in the equivalent photon approximation with impact parameters, for various noncommutative scales, $\rm\Lambda_{NC}$, and incoming nuclear spin-energy combinations. We find that NCQED contribution to the cross section has considerable increase at diphoton invariant mass range higher than $\rm\Lambda_{NC}$, while the SM contribution is strongly suppressed in such region. Our results show that the current ATLAS $\rm\sqrt{s_{NN}} = 5.02$ TeV experiment can only probe $\rm\Lambda_{NC}<100$ GeV region. On the other hand, future hadron-hadron collider proposals could have the potential to extend to $\rm\Lambda_{NC}\lesssim 300$ GeV region, making the performance of $\rm Pb+Pb(\gamma\gamma)\to Pb+Pb\gamma\gamma$ scattering on testing space-time noncommutativity close to that of the previously proposed photon-photon mode of linear electron-positron collider.
[ { "created": "Wed, 5 Feb 2020 15:29:14 GMT", "version": "v1" }, { "created": "Thu, 7 May 2020 14:12:55 GMT", "version": "v2" } ]
2020-06-24
[ [ "Horvat", "Raul", "" ], [ "Latas", "Dusko", "" ], [ "Trampetic", "Josip", "" ], [ "You", "Jiangyang", "" ] ]
The aim of this article is to explore a potential usability of a photon-photon self-interaction from the noncommutative quantum electrodynamics (NCQED) in the case of light-by-light scattering ($\gamma\gamma\to\gamma\gamma$) in ultraperipheral Pb+Pb collisions, a reaction measured recently by ATLAS and planned for future experiments in hadron-hadron colliders. We compute the total cross section from both, the full one-loop standard model (SM) and the tree-level NCQED amplitudes, in the equivalent photon approximation with impact parameters, for various noncommutative scales, $\rm\Lambda_{NC}$, and incoming nuclear spin-energy combinations. We find that NCQED contribution to the cross section has considerable increase at diphoton invariant mass range higher than $\rm\Lambda_{NC}$, while the SM contribution is strongly suppressed in such region. Our results show that the current ATLAS $\rm\sqrt{s_{NN}} = 5.02$ TeV experiment can only probe $\rm\Lambda_{NC}<100$ GeV region. On the other hand, future hadron-hadron collider proposals could have the potential to extend to $\rm\Lambda_{NC}\lesssim 300$ GeV region, making the performance of $\rm Pb+Pb(\gamma\gamma)\to Pb+Pb\gamma\gamma$ scattering on testing space-time noncommutativity close to that of the previously proposed photon-photon mode of linear electron-positron collider.
1803.08521
Miguel Nebot
Francisco J. Botella, Fernando Cornet-Gomez (Valencia U. and IFIC), Miguel Nebot (Lisbon IST and CFTP)
Flavour Conservation in Two Higgs Doublet Models
40 pages, 5 figures, 4 tables. Misleading appendix removed
null
10.1103/PhysRevD.98.035046
IFIC/18-004, CFTP/18-004
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In extensions of the Standard Model with two Higgs doublets, flavour changing Yukawa couplings of the neutral scalars may be present at tree level. In this work we consider the most general scenario in which those flavour changing couplings are absent. We re-analyse the conditions that the Yukawa coupling matrices must obey for such \emph{general flavour conservation} (gFC), and study the one loop renormalisation group evolution of such conditions in both the quark and lepton sectors. We show that gFC in the leptonic sector is one loop stable under the Renormalization Group Evolution (RGE) and in the quark sector we present some new Cabibbo like solution also one loop RGE stable. At a phenomenological level, we obtain the regions for the different gFC parameters that are allowed by the existing experimental constraints related to the 125 GeV Higgs.
[ { "created": "Thu, 22 Mar 2018 18:01:52 GMT", "version": "v1" }, { "created": "Thu, 31 May 2018 14:49:43 GMT", "version": "v2" } ]
2018-09-26
[ [ "Botella", "Francisco J.", "", "Valencia U. and IFIC" ], [ "Cornet-Gomez", "Fernando", "", "Valencia U. and IFIC" ], [ "Nebot", "Miguel", "", "Lisbon IST and CFTP" ] ]
In extensions of the Standard Model with two Higgs doublets, flavour changing Yukawa couplings of the neutral scalars may be present at tree level. In this work we consider the most general scenario in which those flavour changing couplings are absent. We re-analyse the conditions that the Yukawa coupling matrices must obey for such \emph{general flavour conservation} (gFC), and study the one loop renormalisation group evolution of such conditions in both the quark and lepton sectors. We show that gFC in the leptonic sector is one loop stable under the Renormalization Group Evolution (RGE) and in the quark sector we present some new Cabibbo like solution also one loop RGE stable. At a phenomenological level, we obtain the regions for the different gFC parameters that are allowed by the existing experimental constraints related to the 125 GeV Higgs.