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1012.1178
Tzvetalina Stavreva
T. Stavreva, I. Schienbein, F. Arleo, K. Kovarik, F. Olness, J.Y. Yu, J.F. Owens
Probing gluon and heavy-quark nuclear PDFs with photon + heavy quark production in pA collisions
null
JHEP 1101:152,2011
10.1007/JHEP01(2011)152
LPSC-10-140, KA-TP-29-2010
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a detailed phenomenological study of direct photon production in association with a heavy-quark jet in pA collisions at the Relativistic Heavy Ion Collider (RHIC) and at the Large Hadron Collider (LHC) at next-to-leading order in QCD. The dominant contribution to the cross-section comes from the gluon--heavy-quark (gQ) initiated subprocess, making \gamma + Q production a process very sensitive to both the gluon and the heavy-quark parton distribution functions (PDFs). Additionally, the RHIC and LHC experiments are probing complementary kinematic regions in the momentum fraction x_2 carried by the target partons. Thus, the nuclear production ratio R^{\gamma+Q}_{pA} can provide strong constraints, over a broad x-range, on the poorly determined nuclear parton distribution functions which are extremely important for the interpretation of results in heavy-ion collisions.
[ { "created": "Mon, 6 Dec 2010 14:26:19 GMT", "version": "v1" }, { "created": "Wed, 12 Jan 2011 17:50:52 GMT", "version": "v2" } ]
2015-03-17
[ [ "Stavreva", "T.", "" ], [ "Schienbein", "I.", "" ], [ "Arleo", "F.", "" ], [ "Kovarik", "K.", "" ], [ "Olness", "F.", "" ], [ "Yu", "J. Y.", "" ], [ "Owens", "J. F.", "" ] ]
We present a detailed phenomenological study of direct photon production in association with a heavy-quark jet in pA collisions at the Relativistic Heavy Ion Collider (RHIC) and at the Large Hadron Collider (LHC) at next-to-leading order in QCD. The dominant contribution to the cross-section comes from the gluon--heavy-quark (gQ) initiated subprocess, making \gamma + Q production a process very sensitive to both the gluon and the heavy-quark parton distribution functions (PDFs). Additionally, the RHIC and LHC experiments are probing complementary kinematic regions in the momentum fraction x_2 carried by the target partons. Thus, the nuclear production ratio R^{\gamma+Q}_{pA} can provide strong constraints, over a broad x-range, on the poorly determined nuclear parton distribution functions which are extremely important for the interpretation of results in heavy-ion collisions.
hep-ph/0701209
Maxim Dvornikov
Maxim Dvornikov (1 and 2), Jukka Maalampi (1 and 3) ((1) University of Jyv\"askyl\"a, (2) IZMIRAN, (3) Helsinki Institute of Physics)
Evolution of Mixed Dirac Particles Interacting with an External Magnetic Field
10 pages, 1 eps figure, RevTeX4; new appendix devoted to quantum mechanical treatment of neutrino spin-flavor oscillations was added; final variant to be published in Phys. Lett. B
Phys.Lett.B657:217-227,2007
10.1016/j.physletb.2007.10.019
null
hep-ph hep-th
null
We study in the framework of relativistic quantum mechanics the evolution of a system of two Dirac neutrinos that mix with each other and have non-vanishing magnetic moments. The dynamics of this system in an external magnetic field is determined by solving the Pauli-Dirac equation with a given initial condition. We consider first neutrino spin-flavor oscillations in a constant magnetic field and derive an analytical expression for the transition probability of spin-flavor conversion in the limit of small magnetic interactions. We then investigate ultrarelativistic neutrinos in an transversal magnetic field and derive their wave functions and transition probabilities with no limitation for the size of transition magnetic moments. Although we consider neutrinos, our formalism is straightforwardly applicable to any spin-1/2 particles.
[ { "created": "Wed, 24 Jan 2007 20:48:48 GMT", "version": "v1" }, { "created": "Fri, 2 Feb 2007 14:59:49 GMT", "version": "v2" }, { "created": "Wed, 1 Aug 2007 09:19:45 GMT", "version": "v3" }, { "created": "Wed, 10 Oct 2007 07:12:46 GMT", "version": "v4" } ]
2008-11-26
[ [ "Dvornikov", "Maxim", "", "1 and 2" ], [ "Maalampi", "Jukka", "", "1 and 3" ] ]
We study in the framework of relativistic quantum mechanics the evolution of a system of two Dirac neutrinos that mix with each other and have non-vanishing magnetic moments. The dynamics of this system in an external magnetic field is determined by solving the Pauli-Dirac equation with a given initial condition. We consider first neutrino spin-flavor oscillations in a constant magnetic field and derive an analytical expression for the transition probability of spin-flavor conversion in the limit of small magnetic interactions. We then investigate ultrarelativistic neutrinos in an transversal magnetic field and derive their wave functions and transition probabilities with no limitation for the size of transition magnetic moments. Although we consider neutrinos, our formalism is straightforwardly applicable to any spin-1/2 particles.
1812.01860
Roman Zhokhov
T. G. Khunjua, K.G. Klimenko, R. N. Zhokhov-Larionov
Affinity of NJL$_2$ and NJL$_{4}$ model results on duality and pion condensation in chiral asymmetric dense quark matter
Proceedings of XXth International Seminar on High Energy Physics, QUARKS-2018
EPJ Web Conf. 191 (2018) 05016
10.1051/epjconf/201819105016
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we investigate the phase structure of a (1+1) and (3+1)-dimensional quark model with four-quark interaction and in the presence of baryon ($\mu_B$), isospin ($\mu_I$) and chiral isospin ($\mu_{I5}$) chemical potentials. It is shown that the chemical potential $\mu_{I5}$ promotes the appearance of the charged PC phase with nonzero baryon density. Results of both models are qualitatively the same, this fact enhances one's confidence in %the faith in the obtained predictions. It is established that in the large-$N_c$ limit ($N_c$ is the number of colored quarks) there exists a duality correspondence between the chiral symmetry breaking phase and the charged pion condensation one.
[ { "created": "Wed, 5 Dec 2018 08:57:06 GMT", "version": "v1" } ]
2018-12-06
[ [ "Khunjua", "T. G.", "" ], [ "Klimenko", "K. G.", "" ], [ "Zhokhov-Larionov", "R. N.", "" ] ]
In this paper we investigate the phase structure of a (1+1) and (3+1)-dimensional quark model with four-quark interaction and in the presence of baryon ($\mu_B$), isospin ($\mu_I$) and chiral isospin ($\mu_{I5}$) chemical potentials. It is shown that the chemical potential $\mu_{I5}$ promotes the appearance of the charged PC phase with nonzero baryon density. Results of both models are qualitatively the same, this fact enhances one's confidence in %the faith in the obtained predictions. It is established that in the large-$N_c$ limit ($N_c$ is the number of colored quarks) there exists a duality correspondence between the chiral symmetry breaking phase and the charged pion condensation one.
1805.03880
A. N. Ivanov
A. N. Ivanov, R. H\"ollwieser, N. I. Troitskaya, M. Wellenzohn, Ya. A. Berdnikov
Tests of the Standard Model in Neutron Beta Decay with Polarized Neutron and Electron and Unpolarized Proton
15 pages, 1 figure
Phys. Rev. C 98, 035503 (2018)
10.1103/PhysRevC.98.035503
null
hep-ph astro-ph.CO nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse the electron--energy and angular distribution of the neutron beta decay with polarized neutron and electron and unpolarized proton, calculated in Phys. Rev. C 95, 055502 (2017) within the Standard Model (SM), by taking into account the contributions of interactions beyond the SM. After the absorption of vector and axial vector contributions by the axial coupling constant and Cabibbo-Kobayashi-Maskawa (CKM) matrix element (Bhattacharya et al., Phys. Rev. D 85, 054512 (2012) and so on) these are the contributions of scalar and tensor interactions only. The neutron lifetime, correlation coefficients and their averaged values, and asymmetries of the neutron beta decay with polarized neutron and electron are adapted to the analysis of experimental data on searches of contributions of interactions beyond the SM. Using the obtained results we propose some estimates of the values of the scalar and tensor coupling constants of interactions beyond the SM. We use the estimate of the Fierz interference term "b_F = - 0.0028 +/- 0.0026" by Hardy and Towner (Phys. Rev. C 91, 025501 (2015)), the neutron lifetime "tau_n = 880.2(1.0)s"(Particle Data Group, Chin. Phys. C 40, 100001 (2016)) and the experimental data "N_{\exp} = 0.067 +/- 0.011_{\rm stat.} +/- 0.004_{\rm syst.}" for the averaged value of the correlation coefficient of the neutron-electron spin-spin correlations, measured by Kozela et al. (Phys. Ref. C 85, 045501 (2012)). The contributions of G-odd correlations are calculated and found at the level of 10^{-5} in agreement with the results obtained by Gardner and Plaster (Phys. Rev. C 87, 065504 (2013)).
[ { "created": "Thu, 10 May 2018 08:35:36 GMT", "version": "v1" }, { "created": "Mon, 12 Nov 2018 21:53:15 GMT", "version": "v2" } ]
2018-11-14
[ [ "Ivanov", "A. N.", "" ], [ "Höllwieser", "R.", "" ], [ "Troitskaya", "N. I.", "" ], [ "Wellenzohn", "M.", "" ], [ "Berdnikov", "Ya. A.", "" ] ]
We analyse the electron--energy and angular distribution of the neutron beta decay with polarized neutron and electron and unpolarized proton, calculated in Phys. Rev. C 95, 055502 (2017) within the Standard Model (SM), by taking into account the contributions of interactions beyond the SM. After the absorption of vector and axial vector contributions by the axial coupling constant and Cabibbo-Kobayashi-Maskawa (CKM) matrix element (Bhattacharya et al., Phys. Rev. D 85, 054512 (2012) and so on) these are the contributions of scalar and tensor interactions only. The neutron lifetime, correlation coefficients and their averaged values, and asymmetries of the neutron beta decay with polarized neutron and electron are adapted to the analysis of experimental data on searches of contributions of interactions beyond the SM. Using the obtained results we propose some estimates of the values of the scalar and tensor coupling constants of interactions beyond the SM. We use the estimate of the Fierz interference term "b_F = - 0.0028 +/- 0.0026" by Hardy and Towner (Phys. Rev. C 91, 025501 (2015)), the neutron lifetime "tau_n = 880.2(1.0)s"(Particle Data Group, Chin. Phys. C 40, 100001 (2016)) and the experimental data "N_{\exp} = 0.067 +/- 0.011_{\rm stat.} +/- 0.004_{\rm syst.}" for the averaged value of the correlation coefficient of the neutron-electron spin-spin correlations, measured by Kozela et al. (Phys. Ref. C 85, 045501 (2012)). The contributions of G-odd correlations are calculated and found at the level of 10^{-5} in agreement with the results obtained by Gardner and Plaster (Phys. Rev. C 87, 065504 (2013)).
2207.14300
Douglas Tuckler
Yu-Ming Chen, Manibrata Sen, Walter Tangarife, Douglas Tuckler, and Yue Zhang
Core-collapse Supernova Constraint on the Origin of Sterile Neutrino Dark Matter via Neutrino Self-interactions
22 pages, 7 Figures, 3 appendices
null
10.1088/1475-7516/2022/11/014
null
hep-ph astro-ph.CO astro-ph.SR
http://creativecommons.org/licenses/by/4.0/
Novel neutrino self-interaction can open up viable parameter space for the relic abundance of sterile-neutrino dark matter (S$\nu$DM). In this work, we constrain the relic target using core-collapse supernova which features the same fundamental process and a similar environment to the early universe era when S$\nu$DM is dominantly produced. We present a detailed calculation of the effects of a massive scalar mediated neutrino self-interaction on the supernova cooling rate, including the derivation of the thermal potential in the presence of non-zero chemical potentials from plasma species. Our results demonstrate that the supernova cooling argument can cover the neutrino self-interaction parameter space that complements terrestrial and cosmological probes.
[ { "created": "Thu, 28 Jul 2022 18:00:00 GMT", "version": "v1" } ]
2022-11-16
[ [ "Chen", "Yu-Ming", "" ], [ "Sen", "Manibrata", "" ], [ "Tangarife", "Walter", "" ], [ "Tuckler", "Douglas", "" ], [ "Zhang", "Yue", "" ] ]
Novel neutrino self-interaction can open up viable parameter space for the relic abundance of sterile-neutrino dark matter (S$\nu$DM). In this work, we constrain the relic target using core-collapse supernova which features the same fundamental process and a similar environment to the early universe era when S$\nu$DM is dominantly produced. We present a detailed calculation of the effects of a massive scalar mediated neutrino self-interaction on the supernova cooling rate, including the derivation of the thermal potential in the presence of non-zero chemical potentials from plasma species. Our results demonstrate that the supernova cooling argument can cover the neutrino self-interaction parameter space that complements terrestrial and cosmological probes.
1505.01168
Roberto Vega-Morales
Yi Chen, Daniel Stolarski, Roberto Vega-Morales
Golden Probe of the Top Yukuwa
references and footnote added
Phys. Rev. D 92, 053003 (2015)
10.1103/PhysRevD.92.053003
CERN-PH-TH-2015-106, LPT-Orsay-15-32
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a preliminary study of the ability of the Higgs decay to four leptons to shed light on the top quark Yukawa couplings. In particular we examine whether the $h\to 4\ell$ `golden channel' is sensitive to the $CP$ properties of the top quark couplings to the Higgs boson. We show that kinematic distributions are sensitive to interference of the next-to-leading order electroweak corrections with the tree level $ZZ$ contribution. This translates into a sensitivity to the top quark Yukawa couplings such that meaningful constraints on their $CP$ properties can begin to be obtained once $\sim 300$ fb$^{-1}$ of data has been collected at $\sim 14$ TeV, with significant improvements at higher luminosity or with a higher energy hadron collider. This makes the $h\to4\ell$ channel a useful probe of the top quark Yukawa couplings that is qualitatively different from already established searches in $h\to V\gamma$ two body decays, $tth$, and $gg\to h$. We also briefly discuss other potential possibilities for probing the top Yukawa $CP$ properties in $h\to2\ell\gamma$ and $\ell^+\ell^-\to h Z, h\gamma$.
[ { "created": "Tue, 5 May 2015 20:01:38 GMT", "version": "v1" }, { "created": "Mon, 18 May 2015 12:39:40 GMT", "version": "v2" } ]
2015-09-23
[ [ "Chen", "Yi", "" ], [ "Stolarski", "Daniel", "" ], [ "Vega-Morales", "Roberto", "" ] ]
We perform a preliminary study of the ability of the Higgs decay to four leptons to shed light on the top quark Yukawa couplings. In particular we examine whether the $h\to 4\ell$ `golden channel' is sensitive to the $CP$ properties of the top quark couplings to the Higgs boson. We show that kinematic distributions are sensitive to interference of the next-to-leading order electroweak corrections with the tree level $ZZ$ contribution. This translates into a sensitivity to the top quark Yukawa couplings such that meaningful constraints on their $CP$ properties can begin to be obtained once $\sim 300$ fb$^{-1}$ of data has been collected at $\sim 14$ TeV, with significant improvements at higher luminosity or with a higher energy hadron collider. This makes the $h\to4\ell$ channel a useful probe of the top quark Yukawa couplings that is qualitatively different from already established searches in $h\to V\gamma$ two body decays, $tth$, and $gg\to h$. We also briefly discuss other potential possibilities for probing the top Yukawa $CP$ properties in $h\to2\ell\gamma$ and $\ell^+\ell^-\to h Z, h\gamma$.
1209.1376
Kenichi Konishi
Kenichi Konishi
Non-Abelian confinement and the dual gauge symmetry: Many faces of flavor symmetry
Latex 10 pages, 1 figure
null
10.1016/j.nuclphysbps.2012.12.044
IFUP-TH/2012-15
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the physics of confinement based on non-Abelian dual superconductor picture, relying on exact solutions in N=2 supersymmetric QCD and based on the recent developments in our understanding of non-Abelian vortices and monopoles. The non-Abelian monopoles, though they are basically just the 't Hooft-Polyakov SU(2) monopoles embedded in various corners of the larger gauge group, require flavor symmetry in an essential way for their very existence. The phenomenon of flavor-color-flavor separation characterizes the multiple roles flavor symmetry plays in producing quantum-mechanical non-Abelian monopoles.
[ { "created": "Thu, 6 Sep 2012 19:16:02 GMT", "version": "v1" } ]
2015-06-11
[ [ "Konishi", "Kenichi", "" ] ]
We review the physics of confinement based on non-Abelian dual superconductor picture, relying on exact solutions in N=2 supersymmetric QCD and based on the recent developments in our understanding of non-Abelian vortices and monopoles. The non-Abelian monopoles, though they are basically just the 't Hooft-Polyakov SU(2) monopoles embedded in various corners of the larger gauge group, require flavor symmetry in an essential way for their very existence. The phenomenon of flavor-color-flavor separation characterizes the multiple roles flavor symmetry plays in producing quantum-mechanical non-Abelian monopoles.
hep-ph/0005216
Grzegorz Wilk
M.Rybczynski, Z.Wlodarczyk and G.Wilk
Self-organized criticality in atmospheric cascades
gz-compressed .tar file containing LaTeX file and 5 PS files with figures, 4 pages altogether (Nucl. Phys. B style, espcrc2.sty file attached) Presented at XI International Symposium On Very High Energy Cosmic Ray Interaction, Campinas, Brazil, July 17-21, 2000. To be published in Nucl. Phys. B (Proc. Suppl.). Some typos corrected
Nucl.Phys.Proc.Suppl. 97 (2001) 81-84
10.1016/S0920-5632(01)01185-9
null
hep-ph astro-ph nucl-th
null
We argue that atmospheric cascades can be regarded as example of the self-organized criticality and studied by using Levy flights and nonextensive approach. It allows us to understand the scale-invariant energy fluctuations inside cascades in a natural way.
[ { "created": "Mon, 22 May 2000 10:26:35 GMT", "version": "v1" }, { "created": "Thu, 17 Aug 2000 14:35:05 GMT", "version": "v2" } ]
2009-10-31
[ [ "Rybczynski", "M.", "" ], [ "Wlodarczyk", "Z.", "" ], [ "Wilk", "G.", "" ] ]
We argue that atmospheric cascades can be regarded as example of the self-organized criticality and studied by using Levy flights and nonextensive approach. It allows us to understand the scale-invariant energy fluctuations inside cascades in a natural way.
hep-ph/9311264
Leutwyler Heinrich
H. Leutwyler
Nonrelativistic effective Lagrangians
30 pages, BUTP-93/25
Phys.Rev. D49 (1994) 3033-3043
10.1103/PhysRevD.49.3033
null
hep-ph
null
Chiral perturbation theory is extended to nonrelativistic systems with spontaneously broken symmetry. In the effective Lagrangian, order parameters associated with the generators of the group manifest themselves as effective coupling constants of a topological term, which is gauge invariant only up to a total derivative. In the case of the ferromagnet, a term connected with the Brouwer degree dominates the derivative expansion. The general analysis includes antiferromagnetic magnons and phonons, while the effective field theory of fluids or gases is beyond the scope of the method.
[ { "created": "Wed, 10 Nov 1993 18:14:37 GMT", "version": "v1" } ]
2009-10-22
[ [ "Leutwyler", "H.", "" ] ]
Chiral perturbation theory is extended to nonrelativistic systems with spontaneously broken symmetry. In the effective Lagrangian, order parameters associated with the generators of the group manifest themselves as effective coupling constants of a topological term, which is gauge invariant only up to a total derivative. In the case of the ferromagnet, a term connected with the Brouwer degree dominates the derivative expansion. The general analysis includes antiferromagnetic magnons and phonons, while the effective field theory of fluids or gases is beyond the scope of the method.
1802.00962
Albi Kerbizi
A. Kerbizi, X. Artru, Z. Belghobsi, F. Bradamante and A. Martin
Recursive model for the fragmentation of polarized quarks
18 pages, 18 figures
Phys. Rev. D 97, 074010 (2018)
10.1103/PhysRevD.97.074010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model for Monte Carlo simulation of the fragmentation of a polarized quark. The model is based on string dynamics and the ${}^3P_0$ mechanism of quark pair creation at string breaking. The fragmentation is treated as a recursive process, where the splitting function of the subprocess $q \to h + q'$ depends on the spin density matrix of the quark $q$. The ${}^3P_0$ mechanism is parametrized by a complex mass parameter $\mu$, the imaginary part of which is responsible for single spin asymmetries. The model has been implemented in a Monte Carlo program to simulate jets made of pseudoscalar mesons. Results for single hadron and hadron pair transverse-spin asymmetries are found to be in agreement with experimental data from SIDIS and $e^+e^-$ annihilation. The model predictions on the jet-handedness are also discussed.
[ { "created": "Sat, 3 Feb 2018 12:03:29 GMT", "version": "v1" } ]
2018-04-18
[ [ "Kerbizi", "A.", "" ], [ "Artru", "X.", "" ], [ "Belghobsi", "Z.", "" ], [ "Bradamante", "F.", "" ], [ "Martin", "A.", "" ] ]
We present a model for Monte Carlo simulation of the fragmentation of a polarized quark. The model is based on string dynamics and the ${}^3P_0$ mechanism of quark pair creation at string breaking. The fragmentation is treated as a recursive process, where the splitting function of the subprocess $q \to h + q'$ depends on the spin density matrix of the quark $q$. The ${}^3P_0$ mechanism is parametrized by a complex mass parameter $\mu$, the imaginary part of which is responsible for single spin asymmetries. The model has been implemented in a Monte Carlo program to simulate jets made of pseudoscalar mesons. Results for single hadron and hadron pair transverse-spin asymmetries are found to be in agreement with experimental data from SIDIS and $e^+e^-$ annihilation. The model predictions on the jet-handedness are also discussed.
1106.5647
Michael Kr\"amer
Wim Beenakker, Silja Brensing, Monica D'Onofrio, Michael Kr\"amer, Anna Kulesza, Eric Laenen, Mario Martinez, Irene Niessen
Improved squark and gluino mass limits from searches for supersymmetry at hadron colliders
10 pages, 6 figures; removed redundant figures
null
10.1103/PhysRevD.85.075014
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Squarks and gluinos have been searched for at hadron colliders in events with multiple jets and missing transverse energy. No excess has been observed to date, and from a comparison of experimental cross section limits and theoretical cross section predictions one can deduce lower bounds on the squark and gluino masses. We present an improved analysis of squark and gluino mass bounds which is based on state-of-the-art cross section calculations including the summation of large threshold corrections. For illustration, we consider experimental data obtained by the CDF collaboration at the Fermilab Tevatron and discuss the impact of the improved cross section predictions on the squark and gluino mass limits.
[ { "created": "Tue, 28 Jun 2011 12:37:29 GMT", "version": "v1" }, { "created": "Wed, 29 Jun 2011 10:56:44 GMT", "version": "v2" } ]
2013-05-30
[ [ "Beenakker", "Wim", "" ], [ "Brensing", "Silja", "" ], [ "D'Onofrio", "Monica", "" ], [ "Krämer", "Michael", "" ], [ "Kulesza", "Anna", "" ], [ "Laenen", "Eric", "" ], [ "Martinez", "Mario", "" ], [ "Niessen", "Irene", "" ] ]
Squarks and gluinos have been searched for at hadron colliders in events with multiple jets and missing transverse energy. No excess has been observed to date, and from a comparison of experimental cross section limits and theoretical cross section predictions one can deduce lower bounds on the squark and gluino masses. We present an improved analysis of squark and gluino mass bounds which is based on state-of-the-art cross section calculations including the summation of large threshold corrections. For illustration, we consider experimental data obtained by the CDF collaboration at the Fermilab Tevatron and discuss the impact of the improved cross section predictions on the squark and gluino mass limits.
2001.03655
Fatma Aslan
Fatma P. Aslan and Matthias Burkardt
Lorentz invariance relations for twist-3 quark distributions
null
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate twist-3 parton ditribution functions (PDFs) using cut and uncut diagrams. Uncut diagrams lead to a Dirac delta function term. No such term appears when cut diagrams are used. We show that a $\delta(x)$ is necessary to satisfy the Lorentz invariance relations of twist-3 PDFs, except for the Burkhardt-Cottingham sum rule in QCD.
[ { "created": "Fri, 10 Jan 2020 20:27:12 GMT", "version": "v1" } ]
2020-01-14
[ [ "Aslan", "Fatma P.", "" ], [ "Burkardt", "Matthias", "" ] ]
We calculate twist-3 parton ditribution functions (PDFs) using cut and uncut diagrams. Uncut diagrams lead to a Dirac delta function term. No such term appears when cut diagrams are used. We show that a $\delta(x)$ is necessary to satisfy the Lorentz invariance relations of twist-3 PDFs, except for the Burkhardt-Cottingham sum rule in QCD.
hep-ph/0601185
Antonio Pineda
Antonio Pineda and Adrian Signer
Renormalization Group Improved Sum Rule Analysis for the Bottom Quark Mass
4 pages, two figures
Phys.Rev.D73:111501,2006
10.1103/PhysRevD.73.111501
UB-ECM-PF-06-04; IPPP/06/05
hep-ph
null
We study the effect of resumming large logarithms in the determination of the bottom quark mass through a non-relativistic sum rule analysis. Our result is complete at next-to-leading-logarithmic accuracy and includes some known contributions at next-to-next-to-leading logarithmic accuracy. Compared to finite order computations, the reliability of the theoretical evaluation is greatly improved, resulting in a substantially reduced scale dependence and a faster convergent perturbative series. This allows us to significantly improve over previous determinations of the $\MS$ bottom quark mass, $\bar{m}_b$, from non-relativistic sum rules. Our final figure reads $\bar{m}_b(\bar{m}_b)=4.19\pm 0.06$ GeV.
[ { "created": "Mon, 23 Jan 2006 11:50:59 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pineda", "Antonio", "" ], [ "Signer", "Adrian", "" ] ]
We study the effect of resumming large logarithms in the determination of the bottom quark mass through a non-relativistic sum rule analysis. Our result is complete at next-to-leading-logarithmic accuracy and includes some known contributions at next-to-next-to-leading logarithmic accuracy. Compared to finite order computations, the reliability of the theoretical evaluation is greatly improved, resulting in a substantially reduced scale dependence and a faster convergent perturbative series. This allows us to significantly improve over previous determinations of the $\MS$ bottom quark mass, $\bar{m}_b$, from non-relativistic sum rules. Our final figure reads $\bar{m}_b(\bar{m}_b)=4.19\pm 0.06$ GeV.
hep-ph/0511250
Neal Weiner
Spencer Chang (CCPP, NYU), Patrick J. Fox (LBNL), Neal Weiner (CCPP, NYU)
Naturalness and Higgs Decays in the MSSM with a Singlet
3 figures, 1 appendix; version to appear in JHEP; typos fixed and additional references and acknowledgements added
JHEP 0608:068,2006
10.1088/1126-6708/2006/08/068
null
hep-ph
null
The simplest extension of the supersymmetric standard model - the addition of one singlet superfield - can have a profound impact on the Higgs and its decays. We perform a general operator analysis of this scenario, focusing on the phenomenologically distinct scenarios that can arise, and not restricting the scope to the narrow framework of the NMSSM. We reexamine decays to four b quarks and four tau's, finding that they are still generally viable, but at the edge of LEP limits. We find a broad set of Higgs decay modes, some new, including those with four gluon final states, as well as more general six and eight parton final states. We find the phenomenology of these scenarios is dramatically impacted by operators typically ignored, specifically those arising from D-terms in the hidden sector, and those arising from weak-scale colored fields. In addition to sensitivity of m_Z, there are potential tunings of other aspects of the spectrum. In spite of this, these models can be very natural, with light stops and a Higgs as light as 82 GeV. These scenarios motivate further analyses of LEP data as well as studies of the detection capabilities of future colliders to the new decay channels presented.
[ { "created": "Mon, 21 Nov 2005 20:53:26 GMT", "version": "v1" }, { "created": "Fri, 25 Aug 2006 19:22:53 GMT", "version": "v2" } ]
2014-11-18
[ [ "Chang", "Spencer", "", "CCPP, NYU" ], [ "Fox", "Patrick J.", "", "LBNL" ], [ "Weiner", "Neal", "", "CCPP,\n NYU" ] ]
The simplest extension of the supersymmetric standard model - the addition of one singlet superfield - can have a profound impact on the Higgs and its decays. We perform a general operator analysis of this scenario, focusing on the phenomenologically distinct scenarios that can arise, and not restricting the scope to the narrow framework of the NMSSM. We reexamine decays to four b quarks and four tau's, finding that they are still generally viable, but at the edge of LEP limits. We find a broad set of Higgs decay modes, some new, including those with four gluon final states, as well as more general six and eight parton final states. We find the phenomenology of these scenarios is dramatically impacted by operators typically ignored, specifically those arising from D-terms in the hidden sector, and those arising from weak-scale colored fields. In addition to sensitivity of m_Z, there are potential tunings of other aspects of the spectrum. In spite of this, these models can be very natural, with light stops and a Higgs as light as 82 GeV. These scenarios motivate further analyses of LEP data as well as studies of the detection capabilities of future colliders to the new decay channels presented.
hep-ph/0311332
Dilip Kumar Ghosh
N. G. Deshpande, D. K. Ghosh
Flavor and CP violating Z exchange and the rate asymmetry in B --> phi K_S
15 pages, Latex, 2 postscript figures. Sections 2 and 3 are reordered. More references are added. Version to be published in PLB
Phys.Lett.B593:135-142,2004
10.1016/j.physletb.2004.04.060
OITS-742
hep-ph
null
Recent measurements of time dependent CP asymmetry in B --> phi K_S, if confirmed, would indicate a new source of CP violation. We examine flavor violating tree-level Z currents in models with extra down-type quark singlets that arise naturally in string compactified gauge groups like E_6. We evaluate the new operators at the scale mu = m_b in NLO, and using QCD improved factorization to describe B --> phi K_S, find the allowed range of parameters for rho and psi, the magnitude and phase of the flavor violating parameter U_{bs}. This allowed range does satisfy the constraint from flavor changing process b --> s l+ l- . However, further improvement in measurement of these rates could severely constrain the model.
[ { "created": "Wed, 26 Nov 2003 01:11:43 GMT", "version": "v1" }, { "created": "Thu, 5 Feb 2004 00:48:49 GMT", "version": "v2" }, { "created": "Wed, 23 Jun 2004 20:35:22 GMT", "version": "v3" } ]
2014-11-17
[ [ "Deshpande", "N. G.", "" ], [ "Ghosh", "D. K.", "" ] ]
Recent measurements of time dependent CP asymmetry in B --> phi K_S, if confirmed, would indicate a new source of CP violation. We examine flavor violating tree-level Z currents in models with extra down-type quark singlets that arise naturally in string compactified gauge groups like E_6. We evaluate the new operators at the scale mu = m_b in NLO, and using QCD improved factorization to describe B --> phi K_S, find the allowed range of parameters for rho and psi, the magnitude and phase of the flavor violating parameter U_{bs}. This allowed range does satisfy the constraint from flavor changing process b --> s l+ l- . However, further improvement in measurement of these rates could severely constrain the model.
1508.04383
Mikael Berggren
M. Berggren (1), A. Cakir (1,2), D. Kr\"ucker (1), J. List (1), I. A. Melzer-Pellmann (1), B. Safarzadeh Samani (1,3), C. Seitz (1), S. Wayand (4) ((1) DESY, Hamburg, Germany, (2) Istanbul Technical University, Turkey, (3) IPM, Tehran, Iran, (4) KIT IEKP, Karlsruhe, Germany)
Non-Simplified SUSY: Stau-Coannihilation at LHC and ILC
42 pages, 18 figures, 12 tables
null
10.1140/epjc/s10052-016-3914-2
DESY 15-145
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If new phenomena beyond the Standard Model will be discovered at the LHC, the properties of the new particles could be determined with data from the High-Luminosity LHC and from a future linear collider like the ILC. We discuss the possible interplay between measurements at the two accelerators in a concrete example, namely a full SUSY model which features a small stau_1-LSP mass difference. Various channels have been studied using the Snowmass 2013 combined LHC detector implementation in the Delphes simulation package, as well as simulations of the ILD detector concept from the Technical Design Report. We investigate both the LHC and ILC capabilities for discovery, separation and identification of various parts of the spectrum. While some parts would be discovered at the LHC, there is substantial room for further discoveries at the ILC. We finally highlight examples where the precise knowledge about the lower part of the mass spectrum which could be acquired at the ILC would enable a more in-depth analysis of the LHC data with respect to the heavier states.
[ { "created": "Tue, 18 Aug 2015 17:08:23 GMT", "version": "v1" } ]
2016-05-04
[ [ "Berggren", "M.", "" ], [ "Cakir", "A.", "" ], [ "Krücker", "D.", "" ], [ "List", "J.", "" ], [ "Melzer-Pellmann", "I. A.", "" ], [ "Samani", "B. Safarzadeh", "" ], [ "Seitz", "C.", "" ], [ "Wayand", "S.", "" ] ]
If new phenomena beyond the Standard Model will be discovered at the LHC, the properties of the new particles could be determined with data from the High-Luminosity LHC and from a future linear collider like the ILC. We discuss the possible interplay between measurements at the two accelerators in a concrete example, namely a full SUSY model which features a small stau_1-LSP mass difference. Various channels have been studied using the Snowmass 2013 combined LHC detector implementation in the Delphes simulation package, as well as simulations of the ILD detector concept from the Technical Design Report. We investigate both the LHC and ILC capabilities for discovery, separation and identification of various parts of the spectrum. While some parts would be discovered at the LHC, there is substantial room for further discoveries at the ILC. We finally highlight examples where the precise knowledge about the lower part of the mass spectrum which could be acquired at the ILC would enable a more in-depth analysis of the LHC data with respect to the heavier states.
1703.00914
Joe Davighi
Joe Davighi, Philip Harris
Fractal based observables to probe jet substructure of quarks and gluons
[v1] 11 pages 4 figures [v2] 13 pages, 5 figures [v3] 9 pages, 7 figures. v2 added comment on how the observable can preserve infrared safety, updated acknowledgement, added diagram about visualization. v3 added comparison of performance in Herwig and Pythia, added comparison between two different EFO fitting functions, and added figure showing dependence on transverse momentum
Eur.Phys.J. C78 (2018) no.4, 334
10.1140/epjc/s10052-018-5819-8
DAMTP-2017-03-06
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New jet observables are defined which characterize both fractal and scale-dependent contributions to the distribution of hadrons in a jet. These infrared safe observables, named Extended Fractal Observables (EFOs), have been applied to quark-gluon discrimination to demonstrate their potential utility. The EFOs are found to be individually discriminating and only weakly correlated to variables used in existing discriminators. Consequently, their inclusion improves discriminator performance, as here demonstrated with particle level simulation from the parton shower.
[ { "created": "Thu, 2 Mar 2017 19:00:13 GMT", "version": "v1" }, { "created": "Mon, 24 Apr 2017 10:52:27 GMT", "version": "v2" }, { "created": "Wed, 9 May 2018 12:22:26 GMT", "version": "v3" } ]
2018-05-10
[ [ "Davighi", "Joe", "" ], [ "Harris", "Philip", "" ] ]
New jet observables are defined which characterize both fractal and scale-dependent contributions to the distribution of hadrons in a jet. These infrared safe observables, named Extended Fractal Observables (EFOs), have been applied to quark-gluon discrimination to demonstrate their potential utility. The EFOs are found to be individually discriminating and only weakly correlated to variables used in existing discriminators. Consequently, their inclusion improves discriminator performance, as here demonstrated with particle level simulation from the parton shower.
hep-ph/9903282
Wu-Ki Tung
H. L. Lai, J. Huston, S. Kuhlmann, J. Morfin, F. Olness, J. F. Owens, J. Pumplin, W. K. Tung
Global QCD Analysis of Parton Structure of the Nucleon: CTEQ5 Parton Distributions
18 pages in 2up format, 21 figures; This is the version to appear in publication (to appear in Eur. Phys. J. C): minor text modifications; some figures improved in quality; note added in proof concerning QCD evolution added
Eur.Phys.J.C12:375-392,2000
10.1007/s100529900196
MSU-HEP/903100
hep-ph
null
An up-to-date global QCD analysis of high energy lepton-hadron and hadron-hadron interactions is performed to better determine the gluon and quark parton distributions in the nucleon. Improved experimental data on inclusive jet production, in conjunction with precise deep inelastic scattering data, place good constraints on the gluon over a wide range of x; while new data on asymmetries in Drell-Yan processes contribute to better determine the d/u ratio. Comparisons with results of other recent global analyses are made, and the differences are described. Open issues and the general problem of determining the uncertainties of parton distributions are discussed.
[ { "created": "Mon, 8 Mar 1999 05:47:55 GMT", "version": "v1" }, { "created": "Mon, 15 Mar 1999 21:34:27 GMT", "version": "v2" }, { "created": "Fri, 6 Aug 1999 02:53:18 GMT", "version": "v3" } ]
2008-11-26
[ [ "Lai", "H. L.", "" ], [ "Huston", "J.", "" ], [ "Kuhlmann", "S.", "" ], [ "Morfin", "J.", "" ], [ "Olness", "F.", "" ], [ "Owens", "J. F.", "" ], [ "Pumplin", "J.", "" ], [ "Tung", "W. K.", "" ] ]
An up-to-date global QCD analysis of high energy lepton-hadron and hadron-hadron interactions is performed to better determine the gluon and quark parton distributions in the nucleon. Improved experimental data on inclusive jet production, in conjunction with precise deep inelastic scattering data, place good constraints on the gluon over a wide range of x; while new data on asymmetries in Drell-Yan processes contribute to better determine the d/u ratio. Comparisons with results of other recent global analyses are made, and the differences are described. Open issues and the general problem of determining the uncertainties of parton distributions are discussed.
hep-ph/9503491
null
Marco Masetti and Francesca Sartogo
Perturbative predictions for B_c meson production in hadronic collisions
17 pages including 6 figures, uu-encoded compressed postscript file
Phys.Lett. B357 (1995) 659-665
10.1016/0370-2693(95)00908-4
Roma preprint 1099-1995
hep-ph
null
Perturbative cross section for direct B_c meson production in gluon gluon scattering g g --> B_c^+ b \bar{c} is calculated and compared with other existing results. Predictions for hadronic B_c production at Tevatron and LHC are presented and the main sources of uncertainties are discussed.
[ { "created": "Sat, 1 Apr 1995 17:05:17 GMT", "version": "v1" } ]
2009-10-28
[ [ "Masetti", "Marco", "" ], [ "Sartogo", "Francesca", "" ] ]
Perturbative cross section for direct B_c meson production in gluon gluon scattering g g --> B_c^+ b \bar{c} is calculated and compared with other existing results. Predictions for hadronic B_c production at Tevatron and LHC are presented and the main sources of uncertainties are discussed.
hep-ph/0104060
Alberto Accardi
A. Accardi
Semi-hard scatterings at RHIC and LHC: initial conditions and charged multiplicities
4 pages, 4 figures. Talk given at "XXXVI rencontres de Moriond: QCD and hadronic interactions", Les Arcs (FRA), 17-24 march 2001 interactions
null
null
null
hep-ph
null
Minijet production in ultra-relativistic heavy-ion collisions is discussed by taking semi-hard parton rescatterings explicitly into account. At both RHIC and LHC energies we find sizable effects on global characteristics of the nuclear collision like the initial multiplicity and transverse energy of the minijets. The dependence of these quantities on the cutoff that separates soft and hard interactions becomes much smoother after the inclusion of the rescatterings. This allows to define an energy and centrality dependent saturation cutoff and to push perturbative computations to rather low values of the cutoff. As an application we compute the charged multiplicity at mid rapidity and compare it to the recent RHIC data.
[ { "created": "Thu, 5 Apr 2001 15:16:20 GMT", "version": "v1" } ]
2007-05-23
[ [ "Accardi", "A.", "" ] ]
Minijet production in ultra-relativistic heavy-ion collisions is discussed by taking semi-hard parton rescatterings explicitly into account. At both RHIC and LHC energies we find sizable effects on global characteristics of the nuclear collision like the initial multiplicity and transverse energy of the minijets. The dependence of these quantities on the cutoff that separates soft and hard interactions becomes much smoother after the inclusion of the rescatterings. This allows to define an energy and centrality dependent saturation cutoff and to push perturbative computations to rather low values of the cutoff. As an application we compute the charged multiplicity at mid rapidity and compare it to the recent RHIC data.
hep-ph/0306260
Silvano Simula
S. Simula and M. Osipenko
New extraction of alpha_s(MZ) from proton DIS data
revised version to appear in NPB: addition of resummation of anomalous dimensions; negligible changes in the results; no change in the conclusions
Nucl.Phys. B675 (2003) 289-308
10.1016/j.nuclphysb.2003.09.057
preprint RM3-TH/03-6
hep-ph nucl-th
null
An exploratory study for a new determination of the strong coupling constant alpha_s(MZ) from existing world data on the proton structure function F2p in the Q**2-range from ~ 5 to ~ 120 (GeV/c)**2 is presented. The main features of our approach are: 1) the use of low-order Nachtmann moments evaluated with a direct contribution from data larger than 70% of the total; 2) the inclusion of high-order perturbative effects through the soft gluon resummation technique; 3) a direct control over higher-twist effects; and 4) the independence from any specific choice of the x-shape of the input parton distributions. At next-to-leading order we get alpha_s(MZ) = 0.1209 +/- 0.0010 (stat.) +/- 0.0015 (syst.) with a significant dependence upon the order of the moment used. Including soft gluon effects we obtain alpha_s(MZ) = 0.1188 +/- 0.0010 (stat.) +/- 0.0014 (syst.) with a remarkable better stability against the order of the moment. Our findings are compared with recent DIS determinations of alpha_s(MZ) and directions for future improvements are discussed.
[ { "created": "Thu, 26 Jun 2003 12:16:24 GMT", "version": "v1" }, { "created": "Thu, 25 Sep 2003 07:20:43 GMT", "version": "v2" } ]
2015-06-25
[ [ "Simula", "S.", "" ], [ "Osipenko", "M.", "" ] ]
An exploratory study for a new determination of the strong coupling constant alpha_s(MZ) from existing world data on the proton structure function F2p in the Q**2-range from ~ 5 to ~ 120 (GeV/c)**2 is presented. The main features of our approach are: 1) the use of low-order Nachtmann moments evaluated with a direct contribution from data larger than 70% of the total; 2) the inclusion of high-order perturbative effects through the soft gluon resummation technique; 3) a direct control over higher-twist effects; and 4) the independence from any specific choice of the x-shape of the input parton distributions. At next-to-leading order we get alpha_s(MZ) = 0.1209 +/- 0.0010 (stat.) +/- 0.0015 (syst.) with a significant dependence upon the order of the moment used. Including soft gluon effects we obtain alpha_s(MZ) = 0.1188 +/- 0.0010 (stat.) +/- 0.0014 (syst.) with a remarkable better stability against the order of the moment. Our findings are compared with recent DIS determinations of alpha_s(MZ) and directions for future improvements are discussed.
hep-ph/0012349
A. A. Arkhipov
A.A. Arkhipov
Three-body forces, single diffraction dissociation and shadow corrections to hadron-deuteron total cross-sections
Latex, 9 figures, the talk presented at the Workshop "QFTHEP2000", Tver, Russia, September 14-20, 2000
null
null
IHEP 2000-59, Protvino 2000
hep-ph astro-ph nucl-th
null
The relationships between the fundamental dynamics and diffraction phenomena in scattering from two-body composite system are discussed. A new simple formula for the shadow corrections to the total cross-section in scattering from deuteron has been derived and new scaling characteristics with a clear physical interpretation have been established. The effect of weakening the inelastic screening at super-high energies is theoretically discovered. A comparison with the experimental data on proton(antiproton)-deuteron total cross-sections has been performed. It is shown that there is quite a remarkable correspondence of the theory with the experimental data.
[ { "created": "Wed, 27 Dec 2000 18:37:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "Arkhipov", "A. A.", "" ] ]
The relationships between the fundamental dynamics and diffraction phenomena in scattering from two-body composite system are discussed. A new simple formula for the shadow corrections to the total cross-section in scattering from deuteron has been derived and new scaling characteristics with a clear physical interpretation have been established. The effect of weakening the inelastic screening at super-high energies is theoretically discovered. A comparison with the experimental data on proton(antiproton)-deuteron total cross-sections has been performed. It is shown that there is quite a remarkable correspondence of the theory with the experimental data.
1501.00338
Jun Jiang
Jun Jiang, Long-Bin Chen and Cong-Feng Qiao
The QCD NLO Corrections to Inclusive $B^*_c$ Production in $Z^{0}$ Decays
17 pages, 11 figures; v2:typos fixed, references added, Fig.5 replaced, revised version; to appear in PRD
Phys. Rev. D 91, 034033 (2015)
10.1103/PhysRevD.91.034033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the next-to-leading order(NLO) quantum chromodynamics(QCD) corrections to the inclusive process of $Z_0 \rightarrow B^*_c+\bar{c}+b$ under the non-relativistic QCD(NRQCD) factorization scheme. Technical details about contributions from vector and axial-vector currents in dimensional regularization scheme are discussed. Numerical calculation shows that the NLO correction enhances the leading-order decay width by about 50%, and the dependence on renormalization scale $\mu$ is reduced. The uncertainties induced by quark masses and the renormalization scale $\mu$ are also analyzed.
[ { "created": "Fri, 2 Jan 2015 02:21:17 GMT", "version": "v1" }, { "created": "Thu, 12 Feb 2015 01:41:40 GMT", "version": "v2" } ]
2015-03-05
[ [ "Jiang", "Jun", "" ], [ "Chen", "Long-Bin", "" ], [ "Qiao", "Cong-Feng", "" ] ]
We calculate the next-to-leading order(NLO) quantum chromodynamics(QCD) corrections to the inclusive process of $Z_0 \rightarrow B^*_c+\bar{c}+b$ under the non-relativistic QCD(NRQCD) factorization scheme. Technical details about contributions from vector and axial-vector currents in dimensional regularization scheme are discussed. Numerical calculation shows that the NLO correction enhances the leading-order decay width by about 50%, and the dependence on renormalization scale $\mu$ is reduced. The uncertainties induced by quark masses and the renormalization scale $\mu$ are also analyzed.
1811.07528
Katarzyna Krajewska
K. Krajewska, J. Z. Kami\'nski
Threshold effects in electron-positron pair creation from the vacuum: Stabilization and longitudinal vs transverse momentum sharing
8 pages, 8 figures
Phys. Rev. A 100, 012104 (2019)
10.1103/PhysRevA.100.012104
null
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Momentum distributions of electron-positron pairs created from the vacuum by an oscillating in time electric field are calculated in the framework of quantum field theory. A pronounced enhancement of those distributions is observed as the frequency of the electric field passes across the one-photon threshold. Below that threshold the pairs preferentially carry a longitudinal momentum, while above the threshold they tend to carry a transverse momentum. Such momentum sharing has an impact on the number of produced pairs: It grows fast with increasing the field frequency below the threshold but it saturates at a roughly constant value above it. On the other hand, at the fixed frequency above the one-photon threshold, the number of pairs scales quadratically with the field strength. This typically perturbative scaling holds even for large electric fields. Thus, the validity of the perturbation theory is extended here to processes which result in creation of particles with substantial transverse momenta.
[ { "created": "Mon, 19 Nov 2018 07:08:24 GMT", "version": "v1" } ]
2019-07-10
[ [ "Krajewska", "K.", "" ], [ "Kamiński", "J. Z.", "" ] ]
Momentum distributions of electron-positron pairs created from the vacuum by an oscillating in time electric field are calculated in the framework of quantum field theory. A pronounced enhancement of those distributions is observed as the frequency of the electric field passes across the one-photon threshold. Below that threshold the pairs preferentially carry a longitudinal momentum, while above the threshold they tend to carry a transverse momentum. Such momentum sharing has an impact on the number of produced pairs: It grows fast with increasing the field frequency below the threshold but it saturates at a roughly constant value above it. On the other hand, at the fixed frequency above the one-photon threshold, the number of pairs scales quadratically with the field strength. This typically perturbative scaling holds even for large electric fields. Thus, the validity of the perturbation theory is extended here to processes which result in creation of particles with substantial transverse momenta.
hep-ph/0206227
Yadong Yang
Gad Eilam and Yadong Yang
Semi-inclusive Decay $B\to \phi X_s$: Rate and Momentum Spectrum of $\phi$
19 pages, 4 figures
Phys.Rev. D66 (2002) 074010
10.1103/PhysRevD.66.074010
null
hep-ph
null
We study the rate and $\phi$ momentum distribution in semi-inclusive decays $B \to\phi X_s $ induced by the quark level processes $b\to\phi s$ and $b\to\phi s g$, in which the gluon is radiated from the internal charm quark loop or emitted from the virtual gluon of the strong penguin (inner bremsstrahlung). We find ${\cal B}(b\to\phi s)=6.7\times 10^{-5}$ and ${\cal B}(b\to\phi s g)=3.8\times 10^{-5}$. The momentum spectrum of $\phi$ produced by $b\to\phi s g $ is very broad. With the cut $|{\bf k}_{\phi}|\geq 2.0$ GeV, ${\cal B}(b\to\phi s)=6.1\times 10^{-5}$ (where the Fermi motion of the $b$-quark in the $B$-meson is described by a Gaussian), and ${\cal B}(b\to\phi s g)=1.0\times 10^{-5}$. Due to the special nature of $\phi$, many difficulties which hindered a reliable theoretical prediction for $B\to \eta' X_s$ decay are absent in the process $B\to \phi X_s$. Therefore, theoretical predictions for $B\to \phi X_s$ are relatively clean. Moreover, the clear experimental signature of the $\phi$ is of great help. Data for $B\to\phi X_s$, both the branching ratio and the $\phi$ momentum distribution, would teach us about the strength of strong penguins which might be of great importance in the search for CP violation and for new physics at $B$ factories.
[ { "created": "Mon, 24 Jun 2002 06:58:04 GMT", "version": "v1" } ]
2009-11-07
[ [ "Eilam", "Gad", "" ], [ "Yang", "Yadong", "" ] ]
We study the rate and $\phi$ momentum distribution in semi-inclusive decays $B \to\phi X_s $ induced by the quark level processes $b\to\phi s$ and $b\to\phi s g$, in which the gluon is radiated from the internal charm quark loop or emitted from the virtual gluon of the strong penguin (inner bremsstrahlung). We find ${\cal B}(b\to\phi s)=6.7\times 10^{-5}$ and ${\cal B}(b\to\phi s g)=3.8\times 10^{-5}$. The momentum spectrum of $\phi$ produced by $b\to\phi s g $ is very broad. With the cut $|{\bf k}_{\phi}|\geq 2.0$ GeV, ${\cal B}(b\to\phi s)=6.1\times 10^{-5}$ (where the Fermi motion of the $b$-quark in the $B$-meson is described by a Gaussian), and ${\cal B}(b\to\phi s g)=1.0\times 10^{-5}$. Due to the special nature of $\phi$, many difficulties which hindered a reliable theoretical prediction for $B\to \eta' X_s$ decay are absent in the process $B\to \phi X_s$. Therefore, theoretical predictions for $B\to \phi X_s$ are relatively clean. Moreover, the clear experimental signature of the $\phi$ is of great help. Data for $B\to\phi X_s$, both the branching ratio and the $\phi$ momentum distribution, would teach us about the strength of strong penguins which might be of great importance in the search for CP violation and for new physics at $B$ factories.
1109.4297
Nikos Giokaris
Nikos D. Giokaris
Self coupling of the Higgs boson to the Higgs field and predictions for the Higgs mass and production cross section at the Fermilab Tevatron Collider
6 pages, 3 figures
null
null
IASA R10-01 15 July, 2010
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mass-generation mechanism is one of the most important problems in modern particle physics. The discovery and study of the Higgs boson would greatly contribute to the understanding and solving of this problem. One of the unknowns in the Higgs potential is the Higgs quadric self-coupling parameter {\lambda}. A {\lambda} parameter value equal to 1 leads to the prediction that the Standard Model Higgs mass is twice the top quark mass or about 347 GeV. It is, then, argued that this could have a dramatic increase of the SM Higgs production cross section at the Tevatron and the LHC, thus making possible its discovery even at the Tevatron with about 5 fb(-1) of integrated luminosity.
[ { "created": "Tue, 20 Sep 2011 13:58:56 GMT", "version": "v1" } ]
2011-09-21
[ [ "Giokaris", "Nikos D.", "" ] ]
The mass-generation mechanism is one of the most important problems in modern particle physics. The discovery and study of the Higgs boson would greatly contribute to the understanding and solving of this problem. One of the unknowns in the Higgs potential is the Higgs quadric self-coupling parameter {\lambda}. A {\lambda} parameter value equal to 1 leads to the prediction that the Standard Model Higgs mass is twice the top quark mass or about 347 GeV. It is, then, argued that this could have a dramatic increase of the SM Higgs production cross section at the Tevatron and the LHC, thus making possible its discovery even at the Tevatron with about 5 fb(-1) of integrated luminosity.
1904.11265
Sourendu Gupta
Sourendu Gupta and Rishi Sharma
Real time warm pions from the lattice using an effective theory
null
null
null
TIFR/TH/19-16
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lattice measurements provide adequate information to fix the parameters of long distance effective field theories in Euclidean time. Using such a theory, we examine the analytic continuation of long distance correlation functions of composite operators at finite temperature from Euclidean to Minkowski space time. There are two definitions of mass in each regime; in Euclidean these are the screening and pole masses. The analytic continuation of these mass parameters to real time is non-trivial. This is in contrast to the situation at zero temperature.
[ { "created": "Thu, 25 Apr 2019 11:28:27 GMT", "version": "v1" } ]
2019-04-26
[ [ "Gupta", "Sourendu", "" ], [ "Sharma", "Rishi", "" ] ]
Lattice measurements provide adequate information to fix the parameters of long distance effective field theories in Euclidean time. Using such a theory, we examine the analytic continuation of long distance correlation functions of composite operators at finite temperature from Euclidean to Minkowski space time. There are two definitions of mass in each regime; in Euclidean these are the screening and pole masses. The analytic continuation of these mass parameters to real time is non-trivial. This is in contrast to the situation at zero temperature.
1402.2658
Tim M. P. Tait
Andre de Gouvea, Daniel Hernandez, Tim M.P. Tait
Criteria for Natural Hierarchies
v2: corrected discussion of gravitational corrections to include an important contribution previously neglected
Phys. Rev. D 89, 115005 (2014)
10.1103/PhysRevD.89.115005
NUHEP-TH/14-01, UCI-HEP-TR-2013-20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the discovery of a particle that seems rather consistent with the minimal Standard Model Higgs boson, attention turns to questions of naturalness, fine-tuning, and what they imply for physics beyond the Standard Model and its discovery prospects at run II of the LHC. In this article we revisit the issue of naturalness, discussing some implicit assumptions that underly some of the most common statements, which tend to assign physical significance to certain regularization procedures. Vague arguments concerning fine-tuning can lead to conclusions that are too strong and perhaps not as generic as one would hope. Instead, we explore a more pragmatic definition of the hierarchy problem that does not rely on peeking beyond the murky boundaries of quantum field theory: we investigate the fine-tuning of the electroweak scale associated with thresholds from heavy particles, which is both calculable and dependent on the nature of the would-be ultraviolet completion of the Standard Model. We discuss different manifestations of new high-energy scales that are favored by experimental hints for new physics with an eye toward making use of fine-tuning in order to determine natural regions of the new physics parameter spaces.
[ { "created": "Tue, 11 Feb 2014 21:01:05 GMT", "version": "v1" }, { "created": "Tue, 4 Mar 2014 19:50:35 GMT", "version": "v2" } ]
2014-06-11
[ [ "de Gouvea", "Andre", "" ], [ "Hernandez", "Daniel", "" ], [ "Tait", "Tim M. P.", "" ] ]
With the discovery of a particle that seems rather consistent with the minimal Standard Model Higgs boson, attention turns to questions of naturalness, fine-tuning, and what they imply for physics beyond the Standard Model and its discovery prospects at run II of the LHC. In this article we revisit the issue of naturalness, discussing some implicit assumptions that underly some of the most common statements, which tend to assign physical significance to certain regularization procedures. Vague arguments concerning fine-tuning can lead to conclusions that are too strong and perhaps not as generic as one would hope. Instead, we explore a more pragmatic definition of the hierarchy problem that does not rely on peeking beyond the murky boundaries of quantum field theory: we investigate the fine-tuning of the electroweak scale associated with thresholds from heavy particles, which is both calculable and dependent on the nature of the would-be ultraviolet completion of the Standard Model. We discuss different manifestations of new high-energy scales that are favored by experimental hints for new physics with an eye toward making use of fine-tuning in order to determine natural regions of the new physics parameter spaces.
hep-ph/0607224
Dominik Nickel
Dominik Nickel
Extraction of Spectral Functions from Dyson-Schwinger Studies via the Maximum Entropy Method
16 pages, 7 figures
AnnalsPhys.322:1949-1960,2007
10.1016/j.aop.2006.09.002
null
hep-ph hep-lat nucl-th
null
It is shown how to apply the Maximum Entropy Method (MEM) to numerical Dyson-Schwinger studies for the extraction of spectral functions of correlators from their corresponding Euclidean propagators. Differences to the application in lattice QCD are emphasized and, as an example, the spectral functions of massless quarks in cold and dense matter are presented.
[ { "created": "Thu, 20 Jul 2006 11:34:24 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nickel", "Dominik", "" ] ]
It is shown how to apply the Maximum Entropy Method (MEM) to numerical Dyson-Schwinger studies for the extraction of spectral functions of correlators from their corresponding Euclidean propagators. Differences to the application in lattice QCD are emphasized and, as an example, the spectral functions of massless quarks in cold and dense matter are presented.
2203.02004
Sarunas Verner
Simon Clery, Yann Mambrini, Keith A. Olive, Andrey Shkerin, Sarunas Verner
Gravitational Portals with Non-Minimal Couplings
14 pages, 8 figures
null
10.1103/PhysRevD.105.095042
UMN--TH--4116/22, FTPI--MINN--22/07, CERN-TH-2022-025
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
We consider the effects of non-minimal couplings to curvature of the form $\xi_S S^2 R$, for three types of scalars: the Higgs boson, the inflaton, and a scalar dark matter candidate. We compute the abundance of dark matter produced by these non-minimal couplings to gravity and compare to similar results with minimal couplings. We also compute the contribution to the radiation bath during reheating. The main effect is a potential augmentation of the maximum temperature during reheating. A model independent limit of $\mathcal{O}(10^{12})$ GeV is obtained. For couplings $\xi_S \gtrsim \mathcal{O}(1)$, these dominate over minimal gravitational interactions.
[ { "created": "Thu, 3 Mar 2022 20:39:52 GMT", "version": "v1" } ]
2022-06-08
[ [ "Clery", "Simon", "" ], [ "Mambrini", "Yann", "" ], [ "Olive", "Keith A.", "" ], [ "Shkerin", "Andrey", "" ], [ "Verner", "Sarunas", "" ] ]
We consider the effects of non-minimal couplings to curvature of the form $\xi_S S^2 R$, for three types of scalars: the Higgs boson, the inflaton, and a scalar dark matter candidate. We compute the abundance of dark matter produced by these non-minimal couplings to gravity and compare to similar results with minimal couplings. We also compute the contribution to the radiation bath during reheating. The main effect is a potential augmentation of the maximum temperature during reheating. A model independent limit of $\mathcal{O}(10^{12})$ GeV is obtained. For couplings $\xi_S \gtrsim \mathcal{O}(1)$, these dominate over minimal gravitational interactions.
1307.4909
Mikko Laine
M. Laine
Thermal right-handed neutrino production rate in the relativistic regime
37 pages. v2: clarification added; published version
JHEP 1308 (2013) 138
10.1007/JHEP08(2013)138
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production rate of right-handed neutrinos from a Standard Model plasma at a temperature above a hundred GeV is evaluated up to NLO in Standard Model couplings. The results apply in the so-called relativistic regime, referring parametrically to a mass M ~ pi T, generalizing thereby previous NLO results which only apply in the non-relativistic regime M >> pi T. The non-relativistic expansion is observed to converge for M > 15 T, but the smallness of any loop corrections allows it to be used in practice already for M > 4 T. In the latter regime any non-covariant dependence of the differential rate on the spatial momentum is shown to be mild. The loop expansion breaks down in the ultrarelativistic regime M << pi T, but after a simple mass resummation it nevertheless extrapolates reasonably well towards a result obtained previously through complete LPM resummation, apparently confirming a strong enhancement of the rate at high temperatures (which facilitates chemical equilibration). When combined with other ingredients the results may help to improve upon the accuracy of leptogenesis computations operating above the electroweak scale.
[ { "created": "Thu, 18 Jul 2013 11:28:30 GMT", "version": "v1" }, { "created": "Wed, 4 Sep 2013 14:28:46 GMT", "version": "v2" } ]
2015-06-16
[ [ "Laine", "M.", "" ] ]
The production rate of right-handed neutrinos from a Standard Model plasma at a temperature above a hundred GeV is evaluated up to NLO in Standard Model couplings. The results apply in the so-called relativistic regime, referring parametrically to a mass M ~ pi T, generalizing thereby previous NLO results which only apply in the non-relativistic regime M >> pi T. The non-relativistic expansion is observed to converge for M > 15 T, but the smallness of any loop corrections allows it to be used in practice already for M > 4 T. In the latter regime any non-covariant dependence of the differential rate on the spatial momentum is shown to be mild. The loop expansion breaks down in the ultrarelativistic regime M << pi T, but after a simple mass resummation it nevertheless extrapolates reasonably well towards a result obtained previously through complete LPM resummation, apparently confirming a strong enhancement of the rate at high temperatures (which facilitates chemical equilibration). When combined with other ingredients the results may help to improve upon the accuracy of leptogenesis computations operating above the electroweak scale.
1812.07918
Hiroshi Okada
Chao-Qiang Geng, Hiroshi Okada
Resolving $B$-meson anomalies by flavor-dependent gauged symmetries $\displaystyle \prod_{i=1}^3U(1)_{B_i-L_i}$
13 pages, 2 tables, 2 figures; the part of neutral meson mixings is modified
null
null
APCTP Pre2018 - 019
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a model with flavor dependent gauged symmetries of $\displaystyle \prod_{i=1}^3 U(1)_{B_i-L_i}$ with $i$ the family indices. After formulating the renormalizable Yukawa Lagrangian, Higgs potential and kinetic term, we study the lepton sector based on a successful two-zero texture without introducing extra scalar bosons to avoid the dangerous Goldstone bosons. In particular, we discuss the muon related phenomenologies via additional neutral gauge bosons. In our numerical analysis, we explore the allowed parameter space, in which the anomaly of $B \to K^* \bar \mu \mu$ can be explained.
[ { "created": "Wed, 19 Dec 2018 12:56:59 GMT", "version": "v1" }, { "created": "Mon, 29 Apr 2019 11:39:53 GMT", "version": "v2" } ]
2019-04-30
[ [ "Geng", "Chao-Qiang", "" ], [ "Okada", "Hiroshi", "" ] ]
We propose a model with flavor dependent gauged symmetries of $\displaystyle \prod_{i=1}^3 U(1)_{B_i-L_i}$ with $i$ the family indices. After formulating the renormalizable Yukawa Lagrangian, Higgs potential and kinetic term, we study the lepton sector based on a successful two-zero texture without introducing extra scalar bosons to avoid the dangerous Goldstone bosons. In particular, we discuss the muon related phenomenologies via additional neutral gauge bosons. In our numerical analysis, we explore the allowed parameter space, in which the anomaly of $B \to K^* \bar \mu \mu$ can be explained.
1602.08126
C. A. de S. Pires
C. A. de S. Pires, J. G. Rodrigues, P. S. Rodrigues da Silva
Realizing the supersymmetric inverse seesaw model in the framework of R-parity violation
Minor modification of the text. Final version to be published in PLB
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If, on one hand, the inverse seesaw is the paradigm of TeV scale seesaw mechanism, on the other it is a challenge to find scenarios capable of realizing it. In this work we propose a scenario, based on the framework of R-parity violation, that realizes minimally the supersymmetric inverse seesaw mechanism. In it the energy scale parameters involved in the mechanism are recognized as the vacuum expectation values of the scalars that compose the singlet superfields $\hat N^C$ and $\hat S$. We develop also the scalar sector of the model and show that the Higgs mass receives a new tree-level contribution that, when combined with the standard contribution plus loop correction, is capable of attaining $125$GeV without resort to heavy stops.
[ { "created": "Thu, 25 Feb 2016 21:41:27 GMT", "version": "v1" }, { "created": "Tue, 12 Apr 2016 16:51:20 GMT", "version": "v2" }, { "created": "Thu, 2 Jun 2016 13:31:44 GMT", "version": "v3" } ]
2016-06-03
[ [ "Pires", "C. A. de S.", "" ], [ "Rodrigues", "J. G.", "" ], [ "da Silva", "P. S. Rodrigues", "" ] ]
If, on one hand, the inverse seesaw is the paradigm of TeV scale seesaw mechanism, on the other it is a challenge to find scenarios capable of realizing it. In this work we propose a scenario, based on the framework of R-parity violation, that realizes minimally the supersymmetric inverse seesaw mechanism. In it the energy scale parameters involved in the mechanism are recognized as the vacuum expectation values of the scalars that compose the singlet superfields $\hat N^C$ and $\hat S$. We develop also the scalar sector of the model and show that the Higgs mass receives a new tree-level contribution that, when combined with the standard contribution plus loop correction, is capable of attaining $125$GeV without resort to heavy stops.
2207.13714
Fabian Esser
Ricardo Cepedello, Fabian Esser, Martin Hirsch, Veronica Sanz
Mapping the SMEFT to discoverable models
33 pages, 11 figures. Version published in JHEP
null
10.1007/JHEP09(2022)229
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The matching of specific new physics scenarios onto the SMEFT framework is a well-understood procedure. The inverse problem, the matching of the SMEFT to UV scenarios, is more difficult and requires the development of new methods to perform a systematic exploration of models. In this paper we use a diagrammatic technique to construct in an automated way a complete set of possible UV models (given certain, well specified assumptions) that can produce specific groups of SMEFT operators, and illustrate its use by generating models with no tree-level contributions to four-fermion (4F) operators. Those scenarios, which only contribute to 4F at one-loop order, can contain relatively light particles that could be discovered at the LHC in direct searches. For this class of models, we find an interesting interplay between indirect SMEFT and direct searches. We discuss some examples on how this interplay would look like when combining low-energy observables with the SMEFT Higgs-fermion analyses and searches for resonance at the LHC.
[ { "created": "Wed, 27 Jul 2022 18:00:04 GMT", "version": "v1" }, { "created": "Fri, 8 Sep 2023 14:35:00 GMT", "version": "v2" } ]
2023-09-11
[ [ "Cepedello", "Ricardo", "" ], [ "Esser", "Fabian", "" ], [ "Hirsch", "Martin", "" ], [ "Sanz", "Veronica", "" ] ]
The matching of specific new physics scenarios onto the SMEFT framework is a well-understood procedure. The inverse problem, the matching of the SMEFT to UV scenarios, is more difficult and requires the development of new methods to perform a systematic exploration of models. In this paper we use a diagrammatic technique to construct in an automated way a complete set of possible UV models (given certain, well specified assumptions) that can produce specific groups of SMEFT operators, and illustrate its use by generating models with no tree-level contributions to four-fermion (4F) operators. Those scenarios, which only contribute to 4F at one-loop order, can contain relatively light particles that could be discovered at the LHC in direct searches. For this class of models, we find an interesting interplay between indirect SMEFT and direct searches. We discuss some examples on how this interplay would look like when combining low-energy observables with the SMEFT Higgs-fermion analyses and searches for resonance at the LHC.
2105.09350
Bronislav Zakharov
B.G. Zakharov
Jet quenching from heavy to light ion collisions
31 pages, 13 figures
null
10.1007/JHEP09(2021)087
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform an analysis of jet quenching in heavy and light ion collisions for scenarios without and with quark-gluon plasma formation in $pp$ collisions. We find that the results for these scenarios are very similar, and both of them are in reasonable agreement with data for heavy ion collisions. However, their results become differ significantly for light nuclei. Using the parameters fitted to heavy ion data on the nuclear modification factor $R_{AA}$, we make predictions for 0.2 and 7 TeV O+O collisions that can be verified by future experiments at RHIC and the LHC.
[ { "created": "Wed, 19 May 2021 18:33:57 GMT", "version": "v1" }, { "created": "Thu, 7 Oct 2021 17:01:47 GMT", "version": "v2" } ]
2021-10-08
[ [ "Zakharov", "B. G.", "" ] ]
We perform an analysis of jet quenching in heavy and light ion collisions for scenarios without and with quark-gluon plasma formation in $pp$ collisions. We find that the results for these scenarios are very similar, and both of them are in reasonable agreement with data for heavy ion collisions. However, their results become differ significantly for light nuclei. Using the parameters fitted to heavy ion data on the nuclear modification factor $R_{AA}$, we make predictions for 0.2 and 7 TeV O+O collisions that can be verified by future experiments at RHIC and the LHC.
1411.1548
Larry McLerran
Larry McLerran
A Phenomenological Model of the Glasma and Photon Production
null
null
10.5506/APhysPolB.45.2307
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I discuss a phenomenological model for the Glasma. I introduce over occupied distributions for gluons, and compute their time evolution. I use this model to estimate the ratio of quarks to gluons and the entropy production as functions of time. I then discuss photon production at RHIC and LHC, and how geometric scaling and the Glasma might explain generic features of such production.
[ { "created": "Thu, 6 Nov 2014 09:57:19 GMT", "version": "v1" } ]
2015-06-23
[ [ "McLerran", "Larry", "" ] ]
I discuss a phenomenological model for the Glasma. I introduce over occupied distributions for gluons, and compute their time evolution. I use this model to estimate the ratio of quarks to gluons and the entropy production as functions of time. I then discuss photon production at RHIC and LHC, and how geometric scaling and the Glasma might explain generic features of such production.
1810.11420
She-Sheng Xue
Roberto Leonardi, Orlando Panella, Francesco Romeo, Alfredo Gurrola, Hao Sun, She-Sheng Xue
Phenomenology at the LHC of composite particles from strongly interacting Standard Model fermions via four-fermion operators of NJL type
To appear in EPJC. This revised version expands the search for composite fermion F considering all its possible flavors and topologies and highlighting the signatures not yet investigated at LHC
The European Physical Journal C volume 80, Article number: 309 (2020)
10.1140/epjc/s10052-020-7822-0
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new physics scenario shows that four-fermion operators of Nambu-Jona-Lasinio (NJL) type have a strong-coupling UV fixed point, where composite fermions $F$ (bosons $\Pi$) form as bound states of three (two) SM elementary fermions and they couple to their constituents via effective contact interactions at the composite scale $\Lambda \approx {\cal O} $(TeV). We present a phenomenological study to investigate such composite particles at the LHC by computing the production cross sections and decay widths of composite fermions in the context of the relevant experiments at the LHC with $pp$ collisions at $\sqrt{s}={\rm 13}$ TeV and $\sqrt{s}={\rm 14}$ TeV. Systematically examining all the different composite particles $F$ and the signatures with which they can manifest, we found a vast spectrum of composite particles $F$ that has not yet been explored at the LHC. Recasting the recent CMS results of the resonant channel $pp\rightarrow e^+F \rightarrow e^+e^- q\bar{q}'$, we find that the composite fermion mass $m_F$ below 4.25 TeV is excluded for $\Lambda$/$m_F$ = 1. We further highlight the region of parameter space where this specific composite particle $F$ can appear using 3 ab$^{-1}$, expected by the High-Luminosity LHC, computing 3 and 5 $\sigma$ contour plots of its statistical significance.
[ { "created": "Fri, 26 Oct 2018 17:08:16 GMT", "version": "v1" }, { "created": "Thu, 19 Mar 2020 16:31:59 GMT", "version": "v2" } ]
2020-04-13
[ [ "Leonardi", "Roberto", "" ], [ "Panella", "Orlando", "" ], [ "Romeo", "Francesco", "" ], [ "Gurrola", "Alfredo", "" ], [ "Sun", "Hao", "" ], [ "Xue", "She-Sheng", "" ] ]
A new physics scenario shows that four-fermion operators of Nambu-Jona-Lasinio (NJL) type have a strong-coupling UV fixed point, where composite fermions $F$ (bosons $\Pi$) form as bound states of three (two) SM elementary fermions and they couple to their constituents via effective contact interactions at the composite scale $\Lambda \approx {\cal O} $(TeV). We present a phenomenological study to investigate such composite particles at the LHC by computing the production cross sections and decay widths of composite fermions in the context of the relevant experiments at the LHC with $pp$ collisions at $\sqrt{s}={\rm 13}$ TeV and $\sqrt{s}={\rm 14}$ TeV. Systematically examining all the different composite particles $F$ and the signatures with which they can manifest, we found a vast spectrum of composite particles $F$ that has not yet been explored at the LHC. Recasting the recent CMS results of the resonant channel $pp\rightarrow e^+F \rightarrow e^+e^- q\bar{q}'$, we find that the composite fermion mass $m_F$ below 4.25 TeV is excluded for $\Lambda$/$m_F$ = 1. We further highlight the region of parameter space where this specific composite particle $F$ can appear using 3 ab$^{-1}$, expected by the High-Luminosity LHC, computing 3 and 5 $\sigma$ contour plots of its statistical significance.
hep-ph/9807438
Conrad John Burden
C.J.Burden
The effect of the ultraviolet part of the gluon propagator on the heavy quark propagator
9 pages and one postscript figure
Phys. Rev. D 59, 037502 (1999)
10.1103/PhysRevD.59.037502
ANU-HEP-98-5
hep-ph hep-th
null
We revisit our recently proposed formalism for dealing with the heavy quark limit of the quark Dyson-Schwinger equation. An ambiguity inherent in the original version of method is identified and resolved. Our reanalysis illustrates the importance of correctly accounting for the effect of hard gluon momenta on the heavy quark self energy in the vicinity of the bare fermion mass pole.
[ { "created": "Tue, 21 Jul 1998 06:54:58 GMT", "version": "v1" }, { "created": "Tue, 3 Nov 1998 00:53:11 GMT", "version": "v2" } ]
2016-08-25
[ [ "Burden", "C. J.", "" ] ]
We revisit our recently proposed formalism for dealing with the heavy quark limit of the quark Dyson-Schwinger equation. An ambiguity inherent in the original version of method is identified and resolved. Our reanalysis illustrates the importance of correctly accounting for the effect of hard gluon momenta on the heavy quark self energy in the vicinity of the bare fermion mass pole.
hep-ph/9809269
Jose Ramon Espinosa
M. Quiros (IEM, CSIC, Madrid) and J.R. Espinosa (CERN)
What is the upper limit on the lightest supersymmetric Higgs mass?
7 pages, 4 figures, Work presented at PASCOS-98, March 22-29 1998
null
null
CERN-TH/98-292, IEM--FT--180/98
hep-ph
null
In this talk the question of what is the upper bound on the lightest supersymmetric Higgs mass, m_h is addressed. This question is relevant since experimental lower bounds on m_h might implement, in the near future, exclusion of supersymmetry. By imposing (perturbative) unification of the gauge couplings at some high scale \simgt 10^{17} GeV, we have found that for a top-quark mass M_t=175 GeV, and depending on the supersymmetric parameters, this bound can be as high as 205 GeV.
[ { "created": "Fri, 4 Sep 1998 14:35:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Quiros", "M.", "", "IEM, CSIC, Madrid" ], [ "Espinosa", "J. R.", "", "CERN" ] ]
In this talk the question of what is the upper bound on the lightest supersymmetric Higgs mass, m_h is addressed. This question is relevant since experimental lower bounds on m_h might implement, in the near future, exclusion of supersymmetry. By imposing (perturbative) unification of the gauge couplings at some high scale \simgt 10^{17} GeV, we have found that for a top-quark mass M_t=175 GeV, and depending on the supersymmetric parameters, this bound can be as high as 205 GeV.
1705.03694
Shuntaro Sakai
S. Sakai, E. Oset, and A. Ramos
Triangle singularities in $B^-\rightarrow K^-\pi^-D_{s0}^+$ and $B^-\rightarrow K^-\pi^-D_{s1}^+$
18 pages, 15 figures, accepted version for publication in Eur. Phys. J. A
Eur.Phys.J. A54 (2018) no.1, 10
10.1140/epja/i2018-12450-5
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the appearance of structures in the decay of the $B^-$ into $K^- \pi^- D_{s0}^+(2317)$ and $K^- \pi^- D_{s1}^+(2460)$ final states by forming invariant mass distributions of $\pi^- D_{s0}^+$ and $\pi^- D_{s1}^+$ pairs, respectively. The structure in the distribution is associated to the kinematical triangle singularity that appears when the $B^- \to K^- K^{*\,0} D^0$ ($B^- \to K^- K^{*\,0} D^{*\,0}$) decay process is followed by the decay of the $K^{*\,0}$ into $\pi^- K^+$ and the subsequent rescattering of the $K^+ D^0$ ($K^+ D^{*\,0}$) pair forming the $D_{s0}^+(2317)$ ($D_{s1}^+(2460)$) resonance. We find this type of non-resonant peaks at 2850 MeV in the invariant mass of $\pi^- D_{s0}$ pairs from $B^- \to K^- \pi^- D_{s0}^+(2317)$ decays and around 3000 MeV in the invariant mass of $\pi^- D_{s1}^+$ pairs from $B^- \to K^- \pi^- D_{s1}^+(2460)$ decays. By employing the measured branching ratios of the $B^- \to K^- K^{*\,0} D^0$ and $B^- \to K^- K^{*\,0} D^{*\,0}$ decays, we predict the branching ratios for the processes $B^-$ into $K^- \pi^-D_{s0}^+(2317)$ and $K^- \pi^- D_{s1}^+(2460)$, in the vicinity of the triangle singularity peak, to be about $8\times10^{-6}$ and $1\times 10^{-6}$, respectively. The observation of this reaction would also give extra support to the molecular picture of the $D_{s0}^+(2317)$ and $D_{s1}^+(2460)$.
[ { "created": "Wed, 10 May 2017 10:50:29 GMT", "version": "v1" }, { "created": "Tue, 23 May 2017 14:22:45 GMT", "version": "v2" }, { "created": "Fri, 30 Jun 2017 18:55:08 GMT", "version": "v3" }, { "created": "Tue, 30 Jan 2018 17:13:58 GMT", "version": "v4" } ]
2018-01-31
[ [ "Sakai", "S.", "" ], [ "Oset", "E.", "" ], [ "Ramos", "A.", "" ] ]
We study the appearance of structures in the decay of the $B^-$ into $K^- \pi^- D_{s0}^+(2317)$ and $K^- \pi^- D_{s1}^+(2460)$ final states by forming invariant mass distributions of $\pi^- D_{s0}^+$ and $\pi^- D_{s1}^+$ pairs, respectively. The structure in the distribution is associated to the kinematical triangle singularity that appears when the $B^- \to K^- K^{*\,0} D^0$ ($B^- \to K^- K^{*\,0} D^{*\,0}$) decay process is followed by the decay of the $K^{*\,0}$ into $\pi^- K^+$ and the subsequent rescattering of the $K^+ D^0$ ($K^+ D^{*\,0}$) pair forming the $D_{s0}^+(2317)$ ($D_{s1}^+(2460)$) resonance. We find this type of non-resonant peaks at 2850 MeV in the invariant mass of $\pi^- D_{s0}$ pairs from $B^- \to K^- \pi^- D_{s0}^+(2317)$ decays and around 3000 MeV in the invariant mass of $\pi^- D_{s1}^+$ pairs from $B^- \to K^- \pi^- D_{s1}^+(2460)$ decays. By employing the measured branching ratios of the $B^- \to K^- K^{*\,0} D^0$ and $B^- \to K^- K^{*\,0} D^{*\,0}$ decays, we predict the branching ratios for the processes $B^-$ into $K^- \pi^-D_{s0}^+(2317)$ and $K^- \pi^- D_{s1}^+(2460)$, in the vicinity of the triangle singularity peak, to be about $8\times10^{-6}$ and $1\times 10^{-6}$, respectively. The observation of this reaction would also give extra support to the molecular picture of the $D_{s0}^+(2317)$ and $D_{s1}^+(2460)$.
1105.0424
Xavier Calmet
Xavier Calmet and Ting-Cheng Yang
Gravitational Corrections to Fermion Masses in Grand Unified Theories
7 pages
Phys.Rev.D84:037701,2011
10.1103/PhysRevD.84.037701
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reconsider quantum gravitational threshold effects to the unification of fermion masses in Grand Unified Theories. We show that the running of the Planck mass can have a sizable effect on these thresholds which are thus much more important than naively expected. These corrections make any extrapolation from low energy measurements challenging.
[ { "created": "Mon, 2 May 2011 20:00:03 GMT", "version": "v1" } ]
2011-09-13
[ [ "Calmet", "Xavier", "" ], [ "Yang", "Ting-Cheng", "" ] ]
We reconsider quantum gravitational threshold effects to the unification of fermion masses in Grand Unified Theories. We show that the running of the Planck mass can have a sizable effect on these thresholds which are thus much more important than naively expected. These corrections make any extrapolation from low energy measurements challenging.
hep-ph/9412337
Thomas Mannel
Thomas Mannel and Gerhard Schuler
HQQET: An Effective Theory Approach to Heavy Quarkonia Decays
14 pages, LaTeX, no figures
Phys.Lett. B349 (1995) 181-188
10.1016/0370-2693(95)00240-L
CERN-TH.7523/94, TTP 94-31
hep-ph
null
We discuss systems containing a heavy quark and a heavy antiquark in the infinite mass limit of QCD. Studying the limit of equal velocities for both heavy particles, we formulate an effective theory approach to heavy quarkonia-like systems. The method is well suited to processes in which the two heavy quarks annihilate, such as electromagnetic and strong decays of charmonium and bottomonium and weak decays of $B_c$.
[ { "created": "Tue, 20 Dec 1994 19:18:39 GMT", "version": "v1" } ]
2009-10-28
[ [ "Mannel", "Thomas", "" ], [ "Schuler", "Gerhard", "" ] ]
We discuss systems containing a heavy quark and a heavy antiquark in the infinite mass limit of QCD. Studying the limit of equal velocities for both heavy particles, we formulate an effective theory approach to heavy quarkonia-like systems. The method is well suited to processes in which the two heavy quarks annihilate, such as electromagnetic and strong decays of charmonium and bottomonium and weak decays of $B_c$.
hep-ph/0503084
Ismail Turan
Mariana Frank, Ismail Turan (Concordia Univ.) and Marc Sher (William and Mary)
Neutrino Masses in the Effective Rank-5 Subgroups of E_6 II: Supersymmetric Case
27 pages, 2 figures; typos correted, version to be published in Physical Review D
Phys.Rev.D71:113002,2005
10.1103/PhysRevD.71.113002
CUMQ/HEP 133, WM-05-107
hep-ph
null
We present a complete analysis of the neutral fermion sector of supersymmetric E_6-inspired low energy models containing an extra SU(2), concentrating on the Alternate Left-Right and Inert models. We show that the R-parity conserving scenario always exhibits a large Dirac mass for \nu_L with maximal mixing with an isosinglet neutrino, and that R-parity violating scenarios do not change the picture other than allowing further mixing with another isosinglet. In order to recover Standard Model phenomenology, additional assumptions in the form of discrete symmetries and/or new interactions are needed. We introduce and investigate Discrete Symmetry method and Higher Dimensional Operators as mechanisms for solving the neutrino mass and mixing problems in these models.
[ { "created": "Wed, 9 Mar 2005 16:39:12 GMT", "version": "v1" }, { "created": "Mon, 16 May 2005 20:09:26 GMT", "version": "v2" } ]
2011-07-19
[ [ "Frank", "Mariana", "", "Concordia Univ." ], [ "Turan", "Ismail", "", "Concordia Univ." ], [ "Sher", "Marc", "", "William\n and Mary" ] ]
We present a complete analysis of the neutral fermion sector of supersymmetric E_6-inspired low energy models containing an extra SU(2), concentrating on the Alternate Left-Right and Inert models. We show that the R-parity conserving scenario always exhibits a large Dirac mass for \nu_L with maximal mixing with an isosinglet neutrino, and that R-parity violating scenarios do not change the picture other than allowing further mixing with another isosinglet. In order to recover Standard Model phenomenology, additional assumptions in the form of discrete symmetries and/or new interactions are needed. We introduce and investigate Discrete Symmetry method and Higher Dimensional Operators as mechanisms for solving the neutrino mass and mixing problems in these models.
hep-ph/0502042
Yoshiko Kanada-En'yo
Y. Kanada-En'yo, O. Morimatsu, and T. Nishikawa
Axial vector tetraquark with S=+2
20 pages, 5 figures, submitted to Phys.Rev.D
Phys.Rev.D71:094005,2005
10.1103/PhysRevD.71.094005
null
hep-ph
null
Possibility of an axial vector isoscalar tetraquark with $ud\bar{s}\bar{s}$ is discussed. If the pentaquark $\Theta^+(1540)$ has the $(qq)_{\bar{3}}(qq)_{\bar{3}}\bar{q}$ configuration, the isoscalar $ud\bar{s}\bar{s}$($\vartheta^+$-meson) state with $J^P=1^+$ is expected to exist in the mass region lower than or close to the mass of $\Theta^+(1540)$. Within a flux-tube quark model, a possible resonant state of $ud\bar{s}\bar{s}(J^{P}=1^{+})$ is suggested to appear around 1.4 GeV with the width ${\cal{O}}(20\sim 50)$ MeV. We propose that the $\vartheta^+$-meson is a good candidate for the tetraquark search, which would be observed in the $K^+K^+\pi^-$ decay channel.
[ { "created": "Fri, 4 Feb 2005 00:52:22 GMT", "version": "v1" }, { "created": "Wed, 24 Aug 2005 06:27:37 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kanada-En'yo", "Y.", "" ], [ "Morimatsu", "O.", "" ], [ "Nishikawa", "T.", "" ] ]
Possibility of an axial vector isoscalar tetraquark with $ud\bar{s}\bar{s}$ is discussed. If the pentaquark $\Theta^+(1540)$ has the $(qq)_{\bar{3}}(qq)_{\bar{3}}\bar{q}$ configuration, the isoscalar $ud\bar{s}\bar{s}$($\vartheta^+$-meson) state with $J^P=1^+$ is expected to exist in the mass region lower than or close to the mass of $\Theta^+(1540)$. Within a flux-tube quark model, a possible resonant state of $ud\bar{s}\bar{s}(J^{P}=1^{+})$ is suggested to appear around 1.4 GeV with the width ${\cal{O}}(20\sim 50)$ MeV. We propose that the $\vartheta^+$-meson is a good candidate for the tetraquark search, which would be observed in the $K^+K^+\pi^-$ decay channel.
1008.0202
Yasemin Sarac
K. Azizi, M. Bayar, A. Ozpineci, Y. Sarac
The $g_{\Sigma_Q\Sigma_Q\pi}$ Coupling Constant via Light Cone QCD Sum Rules
9 pages, 4 figures
Phys.Rev.D82:076004,2010
10.1103/PhysRevD.82.076004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the most general form of the interpolating currents, the coupling constants $g_{\Sigma_b\Sigma_b\pi}$ and $g_{\Sigma_c\Sigma_c\pi}$ are calculated within the light cone QCD sum rules approach. It is found that $g_{{\Sigma_{c}\Sigma_{c}\pi}}=-8.0\pm1.7$ and $g_{{\Sigma_{b}\Sigma_{b}\pi}}=-11.0\pm2.1$.
[ { "created": "Sun, 1 Aug 2010 19:32:45 GMT", "version": "v1" }, { "created": "Mon, 20 Sep 2010 13:57:14 GMT", "version": "v2" } ]
2014-11-21
[ [ "Azizi", "K.", "" ], [ "Bayar", "M.", "" ], [ "Ozpineci", "A.", "" ], [ "Sarac", "Y.", "" ] ]
Using the most general form of the interpolating currents, the coupling constants $g_{\Sigma_b\Sigma_b\pi}$ and $g_{\Sigma_c\Sigma_c\pi}$ are calculated within the light cone QCD sum rules approach. It is found that $g_{{\Sigma_{c}\Sigma_{c}\pi}}=-8.0\pm1.7$ and $g_{{\Sigma_{b}\Sigma_{b}\pi}}=-11.0\pm2.1$.
hep-ph/0407138
Ara Ioannisian Dr.
A. N. Ioannisian, N. A. Kazarian, A. Yu. Smirnov, D. Wyler
A precise analytical description of the Earth matter effect on oscillations of low energy neutrinos
REVTeX 4, 6 pages, 1 figure, several clarifications added, typos corrected
Phys.Rev. D71 (2005) 033006
10.1103/PhysRevD.71.033006
null
hep-ph
null
We present a formalism for the matter effects in the Earth on low energy neutrino fluxes which is both accurate and has all advantages of a full analytic treatment. The oscillation probabilities are calculated up to second order term in $\epsilon(x) \equiv 2V(x)E/\Delta m^2$ where $V(x)$ is the neutrino potential at position $x$. We show the absence of large undamped phases which makes the expansion in $\epsilon$ well behaved. An improved expansion is presented in terms of the variation of $V(x)$ around a suitable mean value which allows to treat energies up to those relevant for Supernova neutrinos. We discuss also the case of three-neutrino mixing.
[ { "created": "Mon, 12 Jul 2004 17:07:10 GMT", "version": "v1" }, { "created": "Tue, 19 Oct 2004 17:27:24 GMT", "version": "v2" } ]
2009-11-10
[ [ "Ioannisian", "A. N.", "" ], [ "Kazarian", "N. A.", "" ], [ "Smirnov", "A. Yu.", "" ], [ "Wyler", "D.", "" ] ]
We present a formalism for the matter effects in the Earth on low energy neutrino fluxes which is both accurate and has all advantages of a full analytic treatment. The oscillation probabilities are calculated up to second order term in $\epsilon(x) \equiv 2V(x)E/\Delta m^2$ where $V(x)$ is the neutrino potential at position $x$. We show the absence of large undamped phases which makes the expansion in $\epsilon$ well behaved. An improved expansion is presented in terms of the variation of $V(x)$ around a suitable mean value which allows to treat energies up to those relevant for Supernova neutrinos. We discuss also the case of three-neutrino mixing.
hep-ph/0503024
Wayne W. Repko
Alberto Devoto, Stefano Di Chiara and Wayne W. Repko
Noncommutative QED corrections to e^+e^-\to\gamma\gamma\gamma at linear collider energies
version accepted by Physical Review
Phys.Rev.D72:056006,2005
10.1103/PhysRevD.72.056006
null
hep-ph
null
We compute the total cross section as well as angular and energy distributions for process $e^+e^-\to\gamma\gamma\gamma$ with both unpolarized and polarized beams in the framework of noncommutative quantum electrodynamics (NCQED). The calculation is performed in the center of mass of colliding electron and positron and is evaluated for energies and integrated luminosities appropriate to future linear colliders. We find that by using unpolarized beams it is possible to probe the Lorentz symmetry violating azimuthal dependence of the cross section. Furthermore, with polarized beams the left-right asymmetry of the CP violating NCQED amplitudes can be used to obtain bounds on the noncommutative scale $\Lambda_{NC}$ which exceed 1.0 TeV.
[ { "created": "Wed, 2 Mar 2005 15:51:40 GMT", "version": "v1" }, { "created": "Sun, 20 Mar 2005 19:28:35 GMT", "version": "v2" }, { "created": "Fri, 9 Sep 2005 20:52:53 GMT", "version": "v3" } ]
2008-11-26
[ [ "Devoto", "Alberto", "" ], [ "Di Chiara", "Stefano", "" ], [ "Repko", "Wayne W.", "" ] ]
We compute the total cross section as well as angular and energy distributions for process $e^+e^-\to\gamma\gamma\gamma$ with both unpolarized and polarized beams in the framework of noncommutative quantum electrodynamics (NCQED). The calculation is performed in the center of mass of colliding electron and positron and is evaluated for energies and integrated luminosities appropriate to future linear colliders. We find that by using unpolarized beams it is possible to probe the Lorentz symmetry violating azimuthal dependence of the cross section. Furthermore, with polarized beams the left-right asymmetry of the CP violating NCQED amplitudes can be used to obtain bounds on the noncommutative scale $\Lambda_{NC}$ which exceed 1.0 TeV.
hep-ph/0405228
Luis Roca
L. Roca, J. E. Palomar, E. Oset, H. C. Chiang
Unitary chiral dynamics in J/Psi to VPP decays and the role of scalar mesons
29 pages, 10 figures
Nucl.Phys. A744 (2004) 127-155
10.1016/j.nuclphysa.2004.08.004
FTUV-04-0524, IFIC-04-0524
hep-ph
null
We make a theoretical study of the J/Psi decays into \omega\pi\pi, \phi\pi\pi, \omega K \bar{K} and \phi K\bar{K} using the techniques of the chiral unitary approach stressing the important role of the scalar resonances dynamically generated through the final state interaction of the two pseudoscalar mesons. We also discuss the importance of new mechanisms with intermediate exchange of vector and axial-vector mesons and the role played by the OZI rule in the J/\Psi\phi\pi\pi vertex, quantifying its effects. The results nicely reproduce the experimental data for the invariant mass distributions in all the channels considered.
[ { "created": "Mon, 24 May 2004 10:50:56 GMT", "version": "v1" } ]
2009-11-10
[ [ "Roca", "L.", "" ], [ "Palomar", "J. E.", "" ], [ "Oset", "E.", "" ], [ "Chiang", "H. C.", "" ] ]
We make a theoretical study of the J/Psi decays into \omega\pi\pi, \phi\pi\pi, \omega K \bar{K} and \phi K\bar{K} using the techniques of the chiral unitary approach stressing the important role of the scalar resonances dynamically generated through the final state interaction of the two pseudoscalar mesons. We also discuss the importance of new mechanisms with intermediate exchange of vector and axial-vector mesons and the role played by the OZI rule in the J/\Psi\phi\pi\pi vertex, quantifying its effects. The results nicely reproduce the experimental data for the invariant mass distributions in all the channels considered.
2407.17270
Hrachya Asatyan
Christoph Greub, Hrachia M. Asatrian, Hrachya H. Asatryan, Lukas Born and Julian Eicher
Three-loop contributions to $b\to s\gamma$ associated with the current-current operators
18 pages, 7 figures, 2 tables, 1 ancillary file. arXiv admin note: text overlap with arXiv:2303.01714
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In a recent work, we calculated all three-loop diagrams contributing to the decay amplitude for $b \to s \gamma$ where none of the gluons touch the $b$-leg. In the present paper, we complete the calculation by working out all remaining three-loop diagrams (of order $\alpha_s^2$) associated with the current-current operators $O_1$ and $O_2$ at the physical value of the charm-quark mass $m_c$. Using the programs AMFlow and DiffExp to solve the differential equations for the master integrals, we obtained precise numerical results at 23 values for $z=m_c^2/m_b^2$, ranging from $z=1/1000$ to $z=1/5$, along with asymptotic expansions around $z=0$. For certain diagrams, the asymptotic expansion breaks down in the physical $z$-range, necessitating a Taylor expansion (which we do around $z=1/10$). In all expansions, we retained power terms up to $z^{20}$ and included the accompanying $\log(z)$ terms to all powers for asymptotic expansions. Numerical results for the sum of all diagrams (including those calculated in the previous paper) are presented in tabular form, while the mentioned expansions of individual diagram classes are provided electronically. We note that our results for the asymptotic expansions around $z=0$ are in good agreement with those recently published by Fael et al. and Czaja et al..
[ { "created": "Wed, 24 Jul 2024 13:36:28 GMT", "version": "v1" } ]
2024-07-25
[ [ "Greub", "Christoph", "" ], [ "Asatrian", "Hrachia M.", "" ], [ "Asatryan", "Hrachya H.", "" ], [ "Born", "Lukas", "" ], [ "Eicher", "Julian", "" ] ]
In a recent work, we calculated all three-loop diagrams contributing to the decay amplitude for $b \to s \gamma$ where none of the gluons touch the $b$-leg. In the present paper, we complete the calculation by working out all remaining three-loop diagrams (of order $\alpha_s^2$) associated with the current-current operators $O_1$ and $O_2$ at the physical value of the charm-quark mass $m_c$. Using the programs AMFlow and DiffExp to solve the differential equations for the master integrals, we obtained precise numerical results at 23 values for $z=m_c^2/m_b^2$, ranging from $z=1/1000$ to $z=1/5$, along with asymptotic expansions around $z=0$. For certain diagrams, the asymptotic expansion breaks down in the physical $z$-range, necessitating a Taylor expansion (which we do around $z=1/10$). In all expansions, we retained power terms up to $z^{20}$ and included the accompanying $\log(z)$ terms to all powers for asymptotic expansions. Numerical results for the sum of all diagrams (including those calculated in the previous paper) are presented in tabular form, while the mentioned expansions of individual diagram classes are provided electronically. We note that our results for the asymptotic expansions around $z=0$ are in good agreement with those recently published by Fael et al. and Czaja et al..
1911.10025
Daniele Marangotto
Daniele Marangotto
Helicity amplitudes for generic multi-body particle decays featuring multiple decay chains
null
Advances in High Energy Physics (2020) 6674595
10.1155/2020/6674595
null
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
We present the general expression of helicity amplitudes for generic multi-body particle decays characterised by multiple decay chains. This is achieved by addressing for the first time the issue of the matching of final particle spin states among different decay chains in full generality for generic multi-body decays, proposing a method able to match the exact definition of spin states relative to the decaying particle ones. We stress the importance of our result by showing that one of the matching method used in the literature is incorrect, leading to amplitude models violating rotational invariance. The results presented are therefore relevant for performing numerous amplitude analysis, notably those searching for exotic structures like pentaquarks.
[ { "created": "Fri, 22 Nov 2019 13:18:20 GMT", "version": "v1" }, { "created": "Thu, 13 Feb 2020 19:21:43 GMT", "version": "v2" }, { "created": "Tue, 9 Jun 2020 06:40:59 GMT", "version": "v3" }, { "created": "Sat, 28 Nov 2020 10:27:49 GMT", "version": "v4" } ]
2022-09-30
[ [ "Marangotto", "Daniele", "" ] ]
We present the general expression of helicity amplitudes for generic multi-body particle decays characterised by multiple decay chains. This is achieved by addressing for the first time the issue of the matching of final particle spin states among different decay chains in full generality for generic multi-body decays, proposing a method able to match the exact definition of spin states relative to the decaying particle ones. We stress the importance of our result by showing that one of the matching method used in the literature is incorrect, leading to amplitude models violating rotational invariance. The results presented are therefore relevant for performing numerous amplitude analysis, notably those searching for exotic structures like pentaquarks.
hep-ph/0506332
Olga Shekhovtsova
G. Pancheri, O. Shekhovtsova, G. Venanzoni
Test of FSR in the process $e^+e^-\to\pi^+\pi^-\gamma$ at DA$\Phi$NE
7 pages, 4 figures, talk at EURIDICE Midterm Collaboration Meeting, Frascati, 8-12 February
null
null
null
hep-ph
null
In this paper we consider the possibility to test the FSR model in the reaction $e^+e^-\to\pi^+\pi^-\gamma$ at DA$\Phi$NE. We propose to consider the low $Q^2$ region ($Q^2$ is the invariant mass squared of the di-pion system) to study the different models describing $gamma^*\to\pi^+\pi^-\gamma$ interaction. As illustration we compare the scalar QED and Resonance Perturbation Theory prediction for the $e^+e^-\to\pi^+\pi^-\gamma$ cross section. We also consider the contribution coming from the $\phi$ direct decay ($\phi\to\pi^+\pi^-\gamma$). We find the low $Q^2$ region is sensitive to FSR models.
[ { "created": "Thu, 30 Jun 2005 15:52:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pancheri", "G.", "" ], [ "Shekhovtsova", "O.", "" ], [ "Venanzoni", "G.", "" ] ]
In this paper we consider the possibility to test the FSR model in the reaction $e^+e^-\to\pi^+\pi^-\gamma$ at DA$\Phi$NE. We propose to consider the low $Q^2$ region ($Q^2$ is the invariant mass squared of the di-pion system) to study the different models describing $gamma^*\to\pi^+\pi^-\gamma$ interaction. As illustration we compare the scalar QED and Resonance Perturbation Theory prediction for the $e^+e^-\to\pi^+\pi^-\gamma$ cross section. We also consider the contribution coming from the $\phi$ direct decay ($\phi\to\pi^+\pi^-\gamma$). We find the low $Q^2$ region is sensitive to FSR models.
hep-ph/0512320
Danny Marfatia
V. Barger, E. Guarnaccia, D Marfatia
Classification of dark energy models in the (w_0,w_a) plane
11 pages, 3 figures. Classification generalized to include models for which the equation of state crosses the phantom divide line. Published version
Phys.Lett.B635:61-65,2006
10.1016/j.physletb.2006.02.018
null
hep-ph astro-ph gr-qc hep-th
null
We classify dark energy models in a plane of observables that correspond to the common parameterization of a non-constant equation of state, w(a)=w_0 + w_a(1-a), where $a$ is the scale factor of the universe. The models fall into four classes and only two of these classes have a region of overlap in the observable plane. We perform a joint analysis of all Type Ia supernova (SNIa) data compiled by the High-Z SN Search Team (HZT) and the Supernova Legacy Survey (SNLS) and find that no class of models is excluded by current SNIa data. However, an analysis of large scale structure, Ly$\alpha$ forest and bias constraints from SDSS, the Gold SNIa data and WMAP data indicates that non-phantom barotropic models with a a positive sound speed are excluded at the 95% C.L.
[ { "created": "Mon, 26 Dec 2005 20:02:06 GMT", "version": "v1" }, { "created": "Mon, 6 Feb 2006 23:43:15 GMT", "version": "v2" }, { "created": "Fri, 10 Mar 2006 21:40:01 GMT", "version": "v3" } ]
2009-09-15
[ [ "Barger", "V.", "" ], [ "Guarnaccia", "E.", "" ], [ "Marfatia", "D", "" ] ]
We classify dark energy models in a plane of observables that correspond to the common parameterization of a non-constant equation of state, w(a)=w_0 + w_a(1-a), where $a$ is the scale factor of the universe. The models fall into four classes and only two of these classes have a region of overlap in the observable plane. We perform a joint analysis of all Type Ia supernova (SNIa) data compiled by the High-Z SN Search Team (HZT) and the Supernova Legacy Survey (SNLS) and find that no class of models is excluded by current SNIa data. However, an analysis of large scale structure, Ly$\alpha$ forest and bias constraints from SDSS, the Gold SNIa data and WMAP data indicates that non-phantom barotropic models with a a positive sound speed are excluded at the 95% C.L.
hep-ph/0309228
Michael R. Pennington
M.R. Pennington
In the debris of hadron interactions lies the beauty of QCD
Presented at the Workshop on Gluonic Excitations, Thomas Jefferson National Accelerator Laboratory, Newport News, May 2003
null
null
DCPT/03/98, IPPP/03/49
hep-ph
null
Recent progress in understanding the strong physics regime of QCD is described. The role played by condensates, particularly $q{\bar q}$, in breaking chiral symmetry and generating constituent masses for $u$ and $d$ quarks is reviewed. The influence this has on hadrons with vacuum quantum numbers is emphasised. What we know of this sector from recent data on $\phi$-radiative decays and from $D$ decays to light hadrons is discussed. The key to further understanding is comprehensive analyses of such data, including that planned for Hall D at Jefferson Laboratory.
[ { "created": "Fri, 19 Sep 2003 09:23:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pennington", "M. R.", "" ] ]
Recent progress in understanding the strong physics regime of QCD is described. The role played by condensates, particularly $q{\bar q}$, in breaking chiral symmetry and generating constituent masses for $u$ and $d$ quarks is reviewed. The influence this has on hadrons with vacuum quantum numbers is emphasised. What we know of this sector from recent data on $\phi$-radiative decays and from $D$ decays to light hadrons is discussed. The key to further understanding is comprehensive analyses of such data, including that planned for Hall D at Jefferson Laboratory.
1908.02406
Yongseok Oh
Parada T. P. Hutauruk, J. J. Cobos-Martinez, Yongseok Oh, K. Tsushima
Valence-quark distributions of pions and kaons in a nuclear medium
12 pages, REVTeX
Phys. Rev. D 100, 094011 (2019)
10.1103/PhysRevD.100.094011
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In-medium valence-quark distributions of $\pi^+$ and $K^+$ mesons in symmetric nuclear matter are studied by combining the Nambu--Jona-Lasinio model and the quark-meson coupling model. The in-medium properties of the current quarks, which are used as inputs for studying the in-medium pion and kaon properties in the Nambu--Jona-Lasinio model, are calculated within the quark-meson coupling model. The light-quark condensates, light-quark dynamical masses, pion and kaon decay constants, and pion- and kaon-quark coupling constants are found to decrease as nuclear density increases. The obtained valence quark distributions in vacuum for both the $\pi^+$ and $K^+$ could reasonably describe the available experimental data over a wide range of Bjorken-$x$. The in-medium valence $u$-quark distribution in the $\pi^+$ at $Q^2=16~\mbox{GeV}^2$ is found to be almost unchanged compared to the in-vacuum case. However, the in-medium to in-vacuum ratios of both the valence $u$-quark and valence $s$-quark distributions of the $K^+$ meson at $Q^2=16~\mbox{GeV}^2$ increase with nuclear matter density, but show different $x$-dependence. Namely, the ratio for the valence $u$-quark distribution increases with $x$, while that for the valence $s$ quark decreases with $x$. These features are enhanced at higher density regions.
[ { "created": "Wed, 7 Aug 2019 00:18:43 GMT", "version": "v1" }, { "created": "Fri, 15 Nov 2019 23:00:43 GMT", "version": "v2" } ]
2019-11-20
[ [ "Hutauruk", "Parada T. P.", "" ], [ "Cobos-Martinez", "J. J.", "" ], [ "Oh", "Yongseok", "" ], [ "Tsushima", "K.", "" ] ]
In-medium valence-quark distributions of $\pi^+$ and $K^+$ mesons in symmetric nuclear matter are studied by combining the Nambu--Jona-Lasinio model and the quark-meson coupling model. The in-medium properties of the current quarks, which are used as inputs for studying the in-medium pion and kaon properties in the Nambu--Jona-Lasinio model, are calculated within the quark-meson coupling model. The light-quark condensates, light-quark dynamical masses, pion and kaon decay constants, and pion- and kaon-quark coupling constants are found to decrease as nuclear density increases. The obtained valence quark distributions in vacuum for both the $\pi^+$ and $K^+$ could reasonably describe the available experimental data over a wide range of Bjorken-$x$. The in-medium valence $u$-quark distribution in the $\pi^+$ at $Q^2=16~\mbox{GeV}^2$ is found to be almost unchanged compared to the in-vacuum case. However, the in-medium to in-vacuum ratios of both the valence $u$-quark and valence $s$-quark distributions of the $K^+$ meson at $Q^2=16~\mbox{GeV}^2$ increase with nuclear matter density, but show different $x$-dependence. Namely, the ratio for the valence $u$-quark distribution increases with $x$, while that for the valence $s$ quark decreases with $x$. These features are enhanced at higher density regions.
hep-ph/0510295
Dorota Kotlorz
D. Kotlorz, A. Kotlorz
DGLAP evolution of truncated moments of parton densities within two different approaches
17 pages, 6 figures
Acta Phys.Polon.B36:3023,2005
null
null
hep-ph
null
We solve the LO DGLAP QCD evolution equation for truncated Mellin moments of the nucleon nonsinglet structure function. The results are compared with those, obtained in the Chebyshev-polynomial approach for $x$-space solutions. Computations are performed for a wide range of the truncation point $10^{-5}\leq x_0\leq 0.9$ and $1\leq Q^2\leq 100 {\rm GeV}^2$. The agreement is perfect for higher moments ($n\geq 2$) and not too large $x_0$ ($x_0\leq 0.1$), even for a small number of terms in the truncated series (M=4). The accuracy of the truncated moments method increases for larger $M$ and decreases very slowly with increasing $Q^2$. For M=30 the relative error in a case of the first moment at $x_0\leq 0.1$ and $Q^2=10 {\rm GeV}^2$ doesn't exceed 5% independently on the shape of the input parametrisation. This is a quite satisfactory result. Using the truncated moments approach one can avoid uncertainties from the unmeasurable $x\to 0$ region and also study scaling violations without making any assumption on the shape of input parametrisation of parton distributions. Therefore the method of truncated moments seems to be a useful tool in further QCD analyses.
[ { "created": "Fri, 21 Oct 2005 20:28:13 GMT", "version": "v1" } ]
2014-11-18
[ [ "Kotlorz", "D.", "" ], [ "Kotlorz", "A.", "" ] ]
We solve the LO DGLAP QCD evolution equation for truncated Mellin moments of the nucleon nonsinglet structure function. The results are compared with those, obtained in the Chebyshev-polynomial approach for $x$-space solutions. Computations are performed for a wide range of the truncation point $10^{-5}\leq x_0\leq 0.9$ and $1\leq Q^2\leq 100 {\rm GeV}^2$. The agreement is perfect for higher moments ($n\geq 2$) and not too large $x_0$ ($x_0\leq 0.1$), even for a small number of terms in the truncated series (M=4). The accuracy of the truncated moments method increases for larger $M$ and decreases very slowly with increasing $Q^2$. For M=30 the relative error in a case of the first moment at $x_0\leq 0.1$ and $Q^2=10 {\rm GeV}^2$ doesn't exceed 5% independently on the shape of the input parametrisation. This is a quite satisfactory result. Using the truncated moments approach one can avoid uncertainties from the unmeasurable $x\to 0$ region and also study scaling violations without making any assumption on the shape of input parametrisation of parton distributions. Therefore the method of truncated moments seems to be a useful tool in further QCD analyses.
2011.13159
Howard E. Haber
Patrick Draper, Andreas Ekstedt, Howard E. Haber
A natural mechanism for approximate Higgs alignment in the 2HDM
55 pages, 8 figures, 3 tables, and 3 appendices; version 2 adds references, corrects typographical errors and adds one figure; version 3 updates references
Journal of High Energy Physics 05 (2021) 235
10.1007/JHEP05(2021)235
SCIPP-20/03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The 2HDM possesses a neutral scalar interaction eigenstate whose tree-level properties coincide with the Standard Model (SM) Higgs boson. In light of the LHC Higgs data which suggests that the observed Higgs boson is SM-like, it follows that the mixing of the SM Higgs interaction eigenstate with the other neutral scalar interaction eigenstates of the 2HDM should be suppressed, corresponding to the so-called Higgs alignment limit. The exact Higgs alignment limit can arise naturally due to a global symmetry of the scalar potential. If this symmetry is softly broken, then the Higgs alignment limit becomes approximate (although still potentially consistent with the current LHC Higgs data). In this paper, we obtain the approximate Higgs alignment suggested by the LHC Higgs data as a consequence of a softly broken global symmetry of the Higgs Lagrangian. However, this can only be accomplished if the Yukawa sector of the theory is extended. We propose an extended 2HDM with vector-like top quark partners, where explicit mass terms in the top sector provide the source of the soft symmetry breaking of a generalized CP symmetry. In this way, we can realize approximate Higgs alignment without a significant fine-tuning of the model parameters. We then explore the implications of the current LHC bounds on vector-like top quark partners for the success of our proposed scenario.
[ { "created": "Thu, 26 Nov 2020 07:06:11 GMT", "version": "v1" }, { "created": "Fri, 7 May 2021 05:47:44 GMT", "version": "v2" }, { "created": "Mon, 14 Jun 2021 07:40:48 GMT", "version": "v3" } ]
2021-06-15
[ [ "Draper", "Patrick", "" ], [ "Ekstedt", "Andreas", "" ], [ "Haber", "Howard E.", "" ] ]
The 2HDM possesses a neutral scalar interaction eigenstate whose tree-level properties coincide with the Standard Model (SM) Higgs boson. In light of the LHC Higgs data which suggests that the observed Higgs boson is SM-like, it follows that the mixing of the SM Higgs interaction eigenstate with the other neutral scalar interaction eigenstates of the 2HDM should be suppressed, corresponding to the so-called Higgs alignment limit. The exact Higgs alignment limit can arise naturally due to a global symmetry of the scalar potential. If this symmetry is softly broken, then the Higgs alignment limit becomes approximate (although still potentially consistent with the current LHC Higgs data). In this paper, we obtain the approximate Higgs alignment suggested by the LHC Higgs data as a consequence of a softly broken global symmetry of the Higgs Lagrangian. However, this can only be accomplished if the Yukawa sector of the theory is extended. We propose an extended 2HDM with vector-like top quark partners, where explicit mass terms in the top sector provide the source of the soft symmetry breaking of a generalized CP symmetry. In this way, we can realize approximate Higgs alignment without a significant fine-tuning of the model parameters. We then explore the implications of the current LHC bounds on vector-like top quark partners for the success of our proposed scenario.
0705.0101
Qiang Zhao
Qiang Zhao
\chi_{c0,2} decay into light meson pairs and its implication of the scalar meson structures
Minor modifications; Revised version accepted by Phys. Lett. B
Phys.Lett.B659:221-227,2008
10.1016/j.physletb.2007.10.062
null
hep-ph hep-ex
null
In light of the recent data from BES collaboration for $\chi_{c0}\to VV$, $PP$ and $SS$, and from CLEO-c for $\eta\eta$, $\eta^\prime\eta^\prime$ and $\eta\eta^\prime$, we present a detailed analysis of the decays of heavy quarkonia into light meson pairs such as $\chi_{c0,2}\to VV$, $PP$ and $SS$ in a recently proposed parametrization scheme. An overall agreement with the data is achieved in $\chi_{c0,2}\to VV$ and $PP$, while in $\chi_{c0}\to SS$ we find that a possible existence of glueball-$q\bar{q}$ mixings is correlated with the OZI-rule violations, which can be further examined at CLEO-c and BESIII in $\chi_{c0}\to SS$ measurement.
[ { "created": "Tue, 1 May 2007 12:26:15 GMT", "version": "v1" }, { "created": "Wed, 31 Oct 2007 00:55:25 GMT", "version": "v2" } ]
2008-11-26
[ [ "Zhao", "Qiang", "" ] ]
In light of the recent data from BES collaboration for $\chi_{c0}\to VV$, $PP$ and $SS$, and from CLEO-c for $\eta\eta$, $\eta^\prime\eta^\prime$ and $\eta\eta^\prime$, we present a detailed analysis of the decays of heavy quarkonia into light meson pairs such as $\chi_{c0,2}\to VV$, $PP$ and $SS$ in a recently proposed parametrization scheme. An overall agreement with the data is achieved in $\chi_{c0,2}\to VV$ and $PP$, while in $\chi_{c0}\to SS$ we find that a possible existence of glueball-$q\bar{q}$ mixings is correlated with the OZI-rule violations, which can be further examined at CLEO-c and BESIII in $\chi_{c0}\to SS$ measurement.
hep-ph/0211242
David Rayner
S. F. King and D. A. J. Rayner
Twisted Moduli and Supersymmetry Breaking
5 pages, 2 eps figures, ws-procs9x6.cls included. Based on a talk given by D.R. at 1st International Conference on String Phenomenology, Oxford, England, 6-11 Jul 2002
null
10.1142/9789812704917_0049
SHEP 02-32
hep-ph
null
We discuss how localized twisted moduli in type I string theory can provide a string realization of brane world supersymmetry breaking models.
[ { "created": "Fri, 15 Nov 2002 09:27:20 GMT", "version": "v1" } ]
2017-08-23
[ [ "King", "S. F.", "" ], [ "Rayner", "D. A. J.", "" ] ]
We discuss how localized twisted moduli in type I string theory can provide a string realization of brane world supersymmetry breaking models.
2003.13945
Kentaro Nishimura
Kentaro Nishimura and Naoki Yamamoto
Topological term, QCD anomaly, and the eta' chiral soliton lattice in rotating baryonic matter
24 pages, 2 figures; v2: published version
JHEP 07 (2020) 196
10.1007/JHEP07(2020)196
null
hep-ph cond-mat.mes-hall hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the ground states of low-density hadronic matter and high-density color-flavor locked color superconducting phase in three-flavor QCD at finite baryon chemical potential under rotation. We find that, in both cases under sufficiently fast rotation, the combination of the rotation-induced topological term for the eta' meson and the QCD anomaly leads to an inhomogeneous condensate of the eta' meson, known as the chiral soliton lattice (CSL). We find that, when baryon chemical potential is much larger than isospin chemical potential, the critical angular velocity for the realization of the eta' CSL is much smaller than that for the pi_0 CSL found previously. We also argue that the eta' CSL states in flavor-symmetric QCD at low density and high density should be continuously connected, extending the quark-hadron continuity conjecture in the presence of the rotation.
[ { "created": "Tue, 31 Mar 2020 04:06:34 GMT", "version": "v1" }, { "created": "Sat, 1 Aug 2020 06:34:21 GMT", "version": "v2" } ]
2020-08-04
[ [ "Nishimura", "Kentaro", "" ], [ "Yamamoto", "Naoki", "" ] ]
We study the ground states of low-density hadronic matter and high-density color-flavor locked color superconducting phase in three-flavor QCD at finite baryon chemical potential under rotation. We find that, in both cases under sufficiently fast rotation, the combination of the rotation-induced topological term for the eta' meson and the QCD anomaly leads to an inhomogeneous condensate of the eta' meson, known as the chiral soliton lattice (CSL). We find that, when baryon chemical potential is much larger than isospin chemical potential, the critical angular velocity for the realization of the eta' CSL is much smaller than that for the pi_0 CSL found previously. We also argue that the eta' CSL states in flavor-symmetric QCD at low density and high density should be continuously connected, extending the quark-hadron continuity conjecture in the presence of the rotation.
hep-ph/0002081
Csaba Boros
C. Boros, J.T. Londergan and A.W. Thomas
Lambda Polarization in Polarized Proton-Proton Collisions at RHIC
18 pages, 5 figures
Phys.Rev.D62:014021,2000
10.1103/PhysRevD.62.014021
ADP-99-53/T389 and IU/NTC 00-02
hep-ph
null
We discuss Lambda polarization in semi-inclusive proton-proton collisions, with one of the protons longitudinally polarized. The hyperfine interaction responsible for the $\Delta$-$N$ and $\Sigma$-$\Lambda$ mass splittings gives rise to flavor asymmetric fragmentation functions and to sizable polarized non-strange fragmentation functions. We predict large positive Lambda polarization in polarized proton-proton collisions at large rapidities of the produced Lambda, while other models, based on SU(3) flavor symmetric fragmentation functions, predict zero or negative Lambda polarization. The effect of $\Sigma^0$ and $\Sigma^*$ decays is also discussed. Forthcoming experiments at RHIC will be able to differentiate between these predictions.
[ { "created": "Tue, 8 Feb 2000 05:29:05 GMT", "version": "v1" } ]
2010-02-17
[ [ "Boros", "C.", "" ], [ "Londergan", "J. T.", "" ], [ "Thomas", "A. W.", "" ] ]
We discuss Lambda polarization in semi-inclusive proton-proton collisions, with one of the protons longitudinally polarized. The hyperfine interaction responsible for the $\Delta$-$N$ and $\Sigma$-$\Lambda$ mass splittings gives rise to flavor asymmetric fragmentation functions and to sizable polarized non-strange fragmentation functions. We predict large positive Lambda polarization in polarized proton-proton collisions at large rapidities of the produced Lambda, while other models, based on SU(3) flavor symmetric fragmentation functions, predict zero or negative Lambda polarization. The effect of $\Sigma^0$ and $\Sigma^*$ decays is also discussed. Forthcoming experiments at RHIC will be able to differentiate between these predictions.
2209.04134
Surabhi Gupta
Surabhi Gupta, Sudhir Kumar Gupta and Keven Ren
Higgs boson in a flavor-extension of the CMSSM
17 pages, 7 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavour-violating couplings of Higgs boson with stop and scharm quarks could be very important as in addition to lifting the mass of the Higgs boson by a few GeV, it could also play a vital phenomenological role in reducing the Supersymmetry breaking scale significantly. In this work, we investigate effects of such flavour-violating couplings within the Constrained Minimal Supersymmetric Standard Model (CMSSM) framework in the context of LEP data, Higgs data at the LHC, precision observables and the relic density of the dark matter using Bayesian statistics. Our detailed analysis reveals that the most probable values of $m_{0}$, $m_{1/2}$, $A_{0}$, $\tan{\beta}$, $\delta^{LR}_{ct}$ are expected to be around 4.83 TeV, 2.54 TeV, 1.90 TeV, 41.5, and 6.1$\times10^{-2}$, respectively, with flat priors. The corresponding values translate into 3.25 TeV, 2.13 TeV, 1.90 TeV, 44.7, and 5.9$\times10^{-2}$, respectively, if the natural priors are used. Furthermore, a comparison of our model with the CMSSM of flavour-conservation as the base model yields a Bayes factor of about 6 while taking into account all the experimental constraints used in our study. Our analysis also reflects that the lightest neutralino would have a mass of about 1 TeV.
[ { "created": "Fri, 9 Sep 2022 06:16:21 GMT", "version": "v1" } ]
2022-09-12
[ [ "Gupta", "Surabhi", "" ], [ "Gupta", "Sudhir Kumar", "" ], [ "Ren", "Keven", "" ] ]
Flavour-violating couplings of Higgs boson with stop and scharm quarks could be very important as in addition to lifting the mass of the Higgs boson by a few GeV, it could also play a vital phenomenological role in reducing the Supersymmetry breaking scale significantly. In this work, we investigate effects of such flavour-violating couplings within the Constrained Minimal Supersymmetric Standard Model (CMSSM) framework in the context of LEP data, Higgs data at the LHC, precision observables and the relic density of the dark matter using Bayesian statistics. Our detailed analysis reveals that the most probable values of $m_{0}$, $m_{1/2}$, $A_{0}$, $\tan{\beta}$, $\delta^{LR}_{ct}$ are expected to be around 4.83 TeV, 2.54 TeV, 1.90 TeV, 41.5, and 6.1$\times10^{-2}$, respectively, with flat priors. The corresponding values translate into 3.25 TeV, 2.13 TeV, 1.90 TeV, 44.7, and 5.9$\times10^{-2}$, respectively, if the natural priors are used. Furthermore, a comparison of our model with the CMSSM of flavour-conservation as the base model yields a Bayes factor of about 6 while taking into account all the experimental constraints used in our study. Our analysis also reflects that the lightest neutralino would have a mass of about 1 TeV.
hep-ph/9309317
John Collins
John C. Collins
Physics of Polarized pp Collisions
Talk presented at PANIC XIII--Particles and Nuclei International Conference at Perugia, Italy 28 June -- 2 July 1993. 4 pages, LaTeX.
null
null
PSU/TH/132
hep-ph
null
I will summarize the physics that can be investigated with polarized pp collisions. It is technically feasible to use the RHIC collider for accelerating highly polarized protons to a center-of-mass energy of about 400 GeV, with high luminosity. Such collisions can be used to probe the spin-dependence of hard collisions and of partons in a hadron, including the gluons. There are interesting twist 3 phenomena that are likely to be significant in view of the large transverse spin asymmetries at lower energies; this will have important implications for the spin structure of the proton wave function. Recent theoretical developments include the possibility of probing the spin of transversely polarized quarks via asymmetries in the jets they make.
[ { "created": "Thu, 23 Sep 1993 20:20:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Collins", "John C.", "" ] ]
I will summarize the physics that can be investigated with polarized pp collisions. It is technically feasible to use the RHIC collider for accelerating highly polarized protons to a center-of-mass energy of about 400 GeV, with high luminosity. Such collisions can be used to probe the spin-dependence of hard collisions and of partons in a hadron, including the gluons. There are interesting twist 3 phenomena that are likely to be significant in view of the large transverse spin asymmetries at lower energies; this will have important implications for the spin structure of the proton wave function. Recent theoretical developments include the possibility of probing the spin of transversely polarized quarks via asymmetries in the jets they make.
1610.06719
Yueling Yang
Junfeng Sun, Lili Chen, Na Wang, Qin Chang, Jinshu Huang, Yueling Yang
Study on the ${\Upsilon}(1S)$ ${\to}$ $B_{c}M$ weak decays
15 pages, revtex
Advances in High Energy Physisc, 2015, 691261 (2015)
10.1155/2015/691261
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Motivated by the prospects of the potential ${\Upsilon}(1S)$ particle at high-luminosity heavy-flavor experiments, we studied the ${\Upsilon}(1S)$ ${\to}$ $B_{c}M$ weak decays, where $M$ $=$ ${\pi}$, ${\rho}$, $K^{(\ast)}$. The nonfactorizable contributions to hadronic matrix elements are taken into consideration with the QCDF approach. It is found that the CKM-favored ${\Upsilon}(1S)$ ${\to}$ $B_{c}{\rho}$ decay has branching ratio of ${\cal O}(10^{-10})$, which might be measured promisingly by the future experiments.
[ { "created": "Fri, 21 Oct 2016 09:33:27 GMT", "version": "v1" } ]
2016-10-24
[ [ "Sun", "Junfeng", "" ], [ "Chen", "Lili", "" ], [ "Wang", "Na", "" ], [ "Chang", "Qin", "" ], [ "Huang", "Jinshu", "" ], [ "Yang", "Yueling", "" ] ]
Motivated by the prospects of the potential ${\Upsilon}(1S)$ particle at high-luminosity heavy-flavor experiments, we studied the ${\Upsilon}(1S)$ ${\to}$ $B_{c}M$ weak decays, where $M$ $=$ ${\pi}$, ${\rho}$, $K^{(\ast)}$. The nonfactorizable contributions to hadronic matrix elements are taken into consideration with the QCDF approach. It is found that the CKM-favored ${\Upsilon}(1S)$ ${\to}$ $B_{c}{\rho}$ decay has branching ratio of ${\cal O}(10^{-10})$, which might be measured promisingly by the future experiments.
hep-ph/0508200
Richard Luddy
M. M. Islam, R. J. Luddy, A. V. Prokudin
Near Forward pp Elastic Scattering at LHC and Nucleon Structure
49 pages including 17 figures. Submitted to Int. J. Mod. Phys. A
Int.J.Mod.Phys.A21:1-42,2006
10.1142/S0217751X06028473
null
hep-ph
null
High energy proton-proton and antiproton-proton elastic scattering are studied first in a model where the nucleon has an outer cloud and an inner core. Elastic scattering is viewed as due to two processes: a) diffraction scattering originating from cloud-cloud interaction; b) a hard or large |t| scattering originating from one nucleon core scattering off the other via vector meson omega exchange, while their outer clouds interact independently. The omega-exchange amplitude shows that omega behaves like an elementary vector meson at high energy, contrary to a regge pole behavior. This behavior, however, can be understood in the nonlinear sigma-model where omega couples to a topological baryonic current like a gauge boson, and the nucleon is described as a topological soliton. Further investigation shows that the underlying effective field theory model is a gauged linear sigma-model that has not only the pion sector and the Wess-Zumino-Witten action of the nonlinear sigma-model, but also a quark-scalar sector. The nucleon structure that emerges is that the nucleon has an outer cloud of quark-antiquark condensed ground state, an inner core of topological baryonic charge probed by omega, and a still smaller quark-bag containing massless valence quarks. Large |t| pp elastic scattering is attributed to valence quark-quark elastic scattering, which is taken to be due to the hard pomeron. The model is applied to predict pp elastic differential cross section at LHC at c.m. energy 14 TeV and |t| = 0 - 10 GeV*2. If our predicted differential cross section is quantitatively confirmed by precise measurement at LHC by the TOTEM group, then it will indicate that various novel ideas developed over the last four decades to describe the nucleon combine and lead to a unique physical description of its structure.
[ { "created": "Thu, 18 Aug 2005 19:44:25 GMT", "version": "v1" } ]
2011-01-27
[ [ "Islam", "M. M.", "" ], [ "Luddy", "R. J.", "" ], [ "Prokudin", "A. V.", "" ] ]
High energy proton-proton and antiproton-proton elastic scattering are studied first in a model where the nucleon has an outer cloud and an inner core. Elastic scattering is viewed as due to two processes: a) diffraction scattering originating from cloud-cloud interaction; b) a hard or large |t| scattering originating from one nucleon core scattering off the other via vector meson omega exchange, while their outer clouds interact independently. The omega-exchange amplitude shows that omega behaves like an elementary vector meson at high energy, contrary to a regge pole behavior. This behavior, however, can be understood in the nonlinear sigma-model where omega couples to a topological baryonic current like a gauge boson, and the nucleon is described as a topological soliton. Further investigation shows that the underlying effective field theory model is a gauged linear sigma-model that has not only the pion sector and the Wess-Zumino-Witten action of the nonlinear sigma-model, but also a quark-scalar sector. The nucleon structure that emerges is that the nucleon has an outer cloud of quark-antiquark condensed ground state, an inner core of topological baryonic charge probed by omega, and a still smaller quark-bag containing massless valence quarks. Large |t| pp elastic scattering is attributed to valence quark-quark elastic scattering, which is taken to be due to the hard pomeron. The model is applied to predict pp elastic differential cross section at LHC at c.m. energy 14 TeV and |t| = 0 - 10 GeV*2. If our predicted differential cross section is quantitatively confirmed by precise measurement at LHC by the TOTEM group, then it will indicate that various novel ideas developed over the last four decades to describe the nucleon combine and lead to a unique physical description of its structure.
hep-ph/0104007
Hoang Ngoc Long
Hoang Ngoc Long, Le Phuoc Trung, Vo Thanh Van
Rare Kaon Decay K^+ --> \pi^+ \nu \bar{\nu} in SU(3)_C X SU(3)_L X U(1)_N Models
7 pages, 1 figure, latex
J.Exp.Theor.Phys.92:548-551,2001; Zh.Eksp.Teor.Fiz.119:633-637,2001
10.1134/1.1371337
APCTP-2000-004
hep-ph
null
The rare kaon decay K^+ --> \pi^+ \nu \bar{\nu} is considered in the framework of the models based on the SU(3)_C X SU(3)_L X U(1)_N (3 - 3 - 1) gauge group. It is shown that a lower bound of the Z' mass in the 3 - 3 - 1 model with right-handed neutrinos at a value of 3 TeV is derived, while that in the minimal version -- 1.7 TeV.
[ { "created": "Mon, 2 Apr 2001 02:49:39 GMT", "version": "v1" } ]
2008-11-26
[ [ "Long", "Hoang Ngoc", "" ], [ "Trung", "Le Phuoc", "" ], [ "Van", "Vo Thanh", "" ] ]
The rare kaon decay K^+ --> \pi^+ \nu \bar{\nu} is considered in the framework of the models based on the SU(3)_C X SU(3)_L X U(1)_N (3 - 3 - 1) gauge group. It is shown that a lower bound of the Z' mass in the 3 - 3 - 1 model with right-handed neutrinos at a value of 3 TeV is derived, while that in the minimal version -- 1.7 TeV.
0911.2114
Keijo Kajantie
J. Alanen, K. Kajantie, V. Suur-Uski
A gauge/gravity duality model for gauge theory thermodynamics
19 pages, 10 figures
Phys.Rev.D80:126008,2009
10.1103/PhysRevD.80.126008
HIP-2009-25/TH
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a gauge/gravity model for the thermodynamics of a gauge theory with one running coupling. The gravity side contains an ansatz for the metric and a scalar field, on the field theory side one starts by giving an ansatz for the beta function describing the scale dependence of the coupling. The model is based on relating the scale to the extra dimensional coordinate and the beta function to the gravity fields, thereby also determining the scalar field potential. We study three different forms of beta functions of increasing complexity and give semianalytic solutions describing first order or continuous transitions.
[ { "created": "Wed, 11 Nov 2009 11:25:23 GMT", "version": "v1" } ]
2009-12-31
[ [ "Alanen", "J.", "" ], [ "Kajantie", "K.", "" ], [ "Suur-Uski", "V.", "" ] ]
We study a gauge/gravity model for the thermodynamics of a gauge theory with one running coupling. The gravity side contains an ansatz for the metric and a scalar field, on the field theory side one starts by giving an ansatz for the beta function describing the scale dependence of the coupling. The model is based on relating the scale to the extra dimensional coordinate and the beta function to the gravity fields, thereby also determining the scalar field potential. We study three different forms of beta functions of increasing complexity and give semianalytic solutions describing first order or continuous transitions.
hep-ph/0107271
Abdelhak Djouadi
Aseshkrishna Datta, Abdelhak Djouadi, Monoranjan Guchait and Yann Mambrini (LPMT Montpellier)
Charged Higgs production from SUSY particle cascade decays at the LHC
30 pages with 10 figures, latex. Uses axodraw.sty and epsfig.sty
Phys.Rev.D65:015007,2002
10.1103/PhysRevD.65.015007
PM/01-26 (July 2001)
hep-ph
null
We analyze the cascade decays of the scalar quarks and gluinos of the Minimal Supersymmetric extension of the Standard Model, which are abundantly produced at the Large Hadron Collider, into heavier charginos and neutralinos which then decay into the lighter ones and charged Higgs particles, and show that they can have substantial branching fractions. The production rates of these Higgs bosons can be much larger than those from the direct production mechanisms, in particular for intermediate values of the parameter $\tan \beta$, and could therefore allow for the detection of these particles. We also discuss charged Higgs boson production from direct two-body top and bottom squark decays as well as from two- and three-body gluino decays.
[ { "created": "Thu, 26 Jul 2001 12:26:58 GMT", "version": "v1" } ]
2008-11-26
[ [ "Datta", "Aseshkrishna", "", "LPMT Montpellier" ], [ "Djouadi", "Abdelhak", "", "LPMT Montpellier" ], [ "Guchait", "Monoranjan", "", "LPMT Montpellier" ], [ "Mambrini", "Yann", "", "LPMT Montpellier" ] ]
We analyze the cascade decays of the scalar quarks and gluinos of the Minimal Supersymmetric extension of the Standard Model, which are abundantly produced at the Large Hadron Collider, into heavier charginos and neutralinos which then decay into the lighter ones and charged Higgs particles, and show that they can have substantial branching fractions. The production rates of these Higgs bosons can be much larger than those from the direct production mechanisms, in particular for intermediate values of the parameter $\tan \beta$, and could therefore allow for the detection of these particles. We also discuss charged Higgs boson production from direct two-body top and bottom squark decays as well as from two- and three-body gluino decays.
1705.04339
Peter Stoffer
Tobias Isken, Bastian Kubis, Sebastian P. Schneider, Peter Stoffer
Dispersion relations for $\eta'\to\eta\pi\pi$
22 pages, 10 figures; v2: added footnote, version published in EPJC
Eur. Phys. J. C77 (2017) 489
10.1140/epjc/s10052-017-5024-1
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a dispersive analysis of the decay amplitude for $\eta'\to\eta\pi\pi$ that is based on the fundamental principles of analyticity and unitarity. In this framework, final-state interactions are fully taken into account. Our dispersive representation relies only on input for the $\pi\pi$ and $\pi\eta$ scattering phase shifts. Isospin symmetry allows us to describe both the charged and neutral decay channel in terms of the same function. The dispersion relation contains subtraction constants that cannot be fixed by unitarity. We determine these parameters by a fit to Dalitz-plot data from the VES and BES-III experiments. We study the prediction of a low-energy theorem and compare the dispersive fit to variants of chiral perturbation theory.
[ { "created": "Thu, 11 May 2017 18:03:31 GMT", "version": "v1" }, { "created": "Mon, 24 Jul 2017 05:52:51 GMT", "version": "v2" } ]
2017-07-25
[ [ "Isken", "Tobias", "" ], [ "Kubis", "Bastian", "" ], [ "Schneider", "Sebastian P.", "" ], [ "Stoffer", "Peter", "" ] ]
We present a dispersive analysis of the decay amplitude for $\eta'\to\eta\pi\pi$ that is based on the fundamental principles of analyticity and unitarity. In this framework, final-state interactions are fully taken into account. Our dispersive representation relies only on input for the $\pi\pi$ and $\pi\eta$ scattering phase shifts. Isospin symmetry allows us to describe both the charged and neutral decay channel in terms of the same function. The dispersion relation contains subtraction constants that cannot be fixed by unitarity. We determine these parameters by a fit to Dalitz-plot data from the VES and BES-III experiments. We study the prediction of a low-energy theorem and compare the dispersive fit to variants of chiral perturbation theory.
1904.01329
Lauri Niemi
Kimmo Kainulainen, Venus Keus, Lauri Niemi, Kari Rummukainen, Tuomas V.I. Tenkanen, Ville Vaskonen
On the validity of perturbative studies of the electroweak phase transition in the Two Higgs Doublet model
null
null
10.1007/JHEP06(2019)075
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Making use of a dimensionally-reduced effective theory at high temperature, we perform a nonperturbative study of the electroweak phase transition in the Two Higgs Doublet model. We focus on two phenomenologically allowed points in the parameter space, carrying out dynamical lattice simulations to determine the equilibrium properties of the transition. We discuss the shortcomings of conventional perturbative approaches based on the resummed effective potential - regarding the insufficient handling of infrared resummation but also the need to account for corrections beyond 1-loop order in the presence of large scalar couplings - and demonstrate that greater accuracy can be achieved with perturbative methods within the effective theory. We find that in the presence of very large scalar couplings, strong phase transitions cannot be reliably studied with any of the methods.
[ { "created": "Tue, 2 Apr 2019 10:48:49 GMT", "version": "v1" }, { "created": "Mon, 24 Jun 2019 14:05:28 GMT", "version": "v2" } ]
2019-07-24
[ [ "Kainulainen", "Kimmo", "" ], [ "Keus", "Venus", "" ], [ "Niemi", "Lauri", "" ], [ "Rummukainen", "Kari", "" ], [ "Tenkanen", "Tuomas V. I.", "" ], [ "Vaskonen", "Ville", "" ] ]
Making use of a dimensionally-reduced effective theory at high temperature, we perform a nonperturbative study of the electroweak phase transition in the Two Higgs Doublet model. We focus on two phenomenologically allowed points in the parameter space, carrying out dynamical lattice simulations to determine the equilibrium properties of the transition. We discuss the shortcomings of conventional perturbative approaches based on the resummed effective potential - regarding the insufficient handling of infrared resummation but also the need to account for corrections beyond 1-loop order in the presence of large scalar couplings - and demonstrate that greater accuracy can be achieved with perturbative methods within the effective theory. We find that in the presence of very large scalar couplings, strong phase transitions cannot be reliably studied with any of the methods.
hep-ph/0703222
Kyrill Bugaev
Kyrill Bugaev
Quark-Gluon Bags with Surface Tension
10 pages, 5 figures
Phys.Rev.C76:014903,2007
10.1103/PhysRevC.76.014903
null
hep-ph
null
The temperature and chemical potential dependent surface tension of bags is introduced into the gas of quark-gluon bags model. This resolves a long standing problem of a unified description of the first and second order phase transition with the cross-over. Such an approach is necessary to model the complicated properties of quark-gluon plasma and hadronic matter from the first principles of statistical mechanics. The suggested model has an exact analytical solution and allows one to rigorously study the vicinity of the critical endpoint of the deconfinement phase transition. The existence of higher order phase transitions at the critical endpoint is discussed. In addition, we found that at the curve of a zero surface tension coefficient there must exist the surface induced phase tranition of the 2$^{nd}$ or higher order, which separates the pure quark gluon plasma (QGP) from the cross-over states, that are the mixed states of hadrons and QGP bags. Thus, the present model predicts that the critical endpoint of quantum chromodynamics is the tricritical endpoint.
[ { "created": "Tue, 20 Mar 2007 20:01:16 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bugaev", "Kyrill", "" ] ]
The temperature and chemical potential dependent surface tension of bags is introduced into the gas of quark-gluon bags model. This resolves a long standing problem of a unified description of the first and second order phase transition with the cross-over. Such an approach is necessary to model the complicated properties of quark-gluon plasma and hadronic matter from the first principles of statistical mechanics. The suggested model has an exact analytical solution and allows one to rigorously study the vicinity of the critical endpoint of the deconfinement phase transition. The existence of higher order phase transitions at the critical endpoint is discussed. In addition, we found that at the curve of a zero surface tension coefficient there must exist the surface induced phase tranition of the 2$^{nd}$ or higher order, which separates the pure quark gluon plasma (QGP) from the cross-over states, that are the mixed states of hadrons and QGP bags. Thus, the present model predicts that the critical endpoint of quantum chromodynamics is the tricritical endpoint.
hep-ph/9506386
Sasha
Alexander Kusenko (University of Pennsylvania)
Tunneling in quantum field theory with spontaneous symmetry breaking
8 pages, latex, 2 figures appended (uuencoded postscript); complete postscript file is available at ftp://dept.physics.upenn.edu/pub/Kusenko/UPR671T.ps
Phys.Lett. B358 (1995) 47-50
10.1016/0370-2693(95)00995-W
null
hep-ph cond-mat gr-qc hep-th
null
Tunneling in quantum field theory is well understood in the case of a single scalar field. However, in theories with spontaneous symmetry breaking, one has to take into account the additional zero modes which appear due to the Goldstone phenomenon. We calculate the false vacuum decay rate in this case. The result may differ significantly from the tunneling rates in the absence of symmetry breaking.
[ { "created": "Wed, 21 Jun 1995 21:18:13 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kusenko", "Alexander", "", "University of Pennsylvania" ] ]
Tunneling in quantum field theory is well understood in the case of a single scalar field. However, in theories with spontaneous symmetry breaking, one has to take into account the additional zero modes which appear due to the Goldstone phenomenon. We calculate the false vacuum decay rate in this case. The result may differ significantly from the tunneling rates in the absence of symmetry breaking.
hep-ph/0607171
Alexander E. Dorokhov
A.E. Dorokhov, W. Broniowski, E. Ruiz Arriola
Photon distribution amplitudes and light-cone wave functions in chiral quark models
24 pages, 15 figures
Phys.Rev. D74 (2006) 054023
10.1103/PhysRevD.74.054023
null
hep-ph
null
The leading- and higher-twist distribution amplitudes and light-cone wave functions of real and virtual photons are analyzed in chiral quark models. The calculations are performed in the nonlocal quark model based on the instanton picture of QCD vacuum, as well as in the spectral quark model and the Nambu--Jona-Lasinio model with the Pauli-Villars regulator, which both treat interaction of quarks with external fields locally. We find that in all considered models the leading-twist distribution amplitudes of the real photon defined at the quark-model momentum scale are constant or remarkably close to the constant in the $x$ variable, thus are far from the asymptotic limit form. The QCD evolution to higher momentum scales is necessary and we carry it out at the leading order of the perturbative theory for the leading-twist amplitudes. We provide estimates for the magnetic susceptibility of the quark condensate $\chi_m$ and the coupling $f_{3\gamma}$, which in the nonlocal model turn out to be close to the estimates from QCD sum rules. We find the higher-twist distribution amplitudes at the quark model scale and compare them to the Wandzura-Wilczek estimates. In addition, in the spectral model we evaluate the distribution amplitudes and light-cone wave functions of the $\rho$-meson.
[ { "created": "Fri, 14 Jul 2006 15:20:12 GMT", "version": "v1" } ]
2009-11-11
[ [ "Dorokhov", "A. E.", "" ], [ "Broniowski", "W.", "" ], [ "Arriola", "E. Ruiz", "" ] ]
The leading- and higher-twist distribution amplitudes and light-cone wave functions of real and virtual photons are analyzed in chiral quark models. The calculations are performed in the nonlocal quark model based on the instanton picture of QCD vacuum, as well as in the spectral quark model and the Nambu--Jona-Lasinio model with the Pauli-Villars regulator, which both treat interaction of quarks with external fields locally. We find that in all considered models the leading-twist distribution amplitudes of the real photon defined at the quark-model momentum scale are constant or remarkably close to the constant in the $x$ variable, thus are far from the asymptotic limit form. The QCD evolution to higher momentum scales is necessary and we carry it out at the leading order of the perturbative theory for the leading-twist amplitudes. We provide estimates for the magnetic susceptibility of the quark condensate $\chi_m$ and the coupling $f_{3\gamma}$, which in the nonlocal model turn out to be close to the estimates from QCD sum rules. We find the higher-twist distribution amplitudes at the quark model scale and compare them to the Wandzura-Wilczek estimates. In addition, in the spectral model we evaluate the distribution amplitudes and light-cone wave functions of the $\rho$-meson.
2403.02237
Tanay Pathak
Souvik Bera and Tanay Pathak
Analytic continuations and numerical evaluation of the Appell $F_1$, $F_3$, Lauricella $F_D^{(3)}$ and Lauricella-Saran $F_S^{(3)}$ and their Application to Feynman Integrals
25 pages, 1 figure, Repository see https://github.com/souvik5151/Appell_Lauricella_Saran_functions
null
null
null
hep-ph cs.MS hep-th math-ph math.MP
http://creativecommons.org/licenses/by/4.0/
We present our investigation of the study of two variable hypergeometric series, namely Appell $F_{1}$ and $F_{3}$ series, and obtain a comprehensive list of its analytic continuations enough to cover the whole real $(x,y)$ plane, except on their singular loci. We also derive analytic continuations of their 3-variable generalization, the Lauricella $F_{D}^{(3)}$ series and the Lauricella-Saran $F_{S}^{(3)}$ series, leveraging the analytic continuations of $F_{1}$ and $F_{3}$, which ensures that the whole real $(x,y,z)$ space is covered, except on the singular loci of these functions. While these studies are motivated by the frequent occurrence of these multivariable hypergeometric functions in Feynman integral evaluation, they can also be used whenever they appear in other branches of mathematical physics. To facilitate their practical use, we provide four packages: $\texttt{AppellF1.wl}$, $\texttt{AppellF3.wl}$, $\texttt{LauricellaFD.wl}$, and $\texttt{LauricellaSaranFS.wl}$ in $\textit{MATHEMATICA}$. These packages are applicable for generic as well as non-generic values of parameters, keeping in mind their utilities in the evaluation of the Feynman integrals. We explicitly present various physical applications of these packages in the context of Feynman integral evaluation and compare the results using other means as well. Various $\textit{MATHEMATICA}$ notebooks demonstrating different numerical results are also provided along with this paper.
[ { "created": "Mon, 4 Mar 2024 17:29:25 GMT", "version": "v1" } ]
2024-03-05
[ [ "Bera", "Souvik", "" ], [ "Pathak", "Tanay", "" ] ]
We present our investigation of the study of two variable hypergeometric series, namely Appell $F_{1}$ and $F_{3}$ series, and obtain a comprehensive list of its analytic continuations enough to cover the whole real $(x,y)$ plane, except on their singular loci. We also derive analytic continuations of their 3-variable generalization, the Lauricella $F_{D}^{(3)}$ series and the Lauricella-Saran $F_{S}^{(3)}$ series, leveraging the analytic continuations of $F_{1}$ and $F_{3}$, which ensures that the whole real $(x,y,z)$ space is covered, except on the singular loci of these functions. While these studies are motivated by the frequent occurrence of these multivariable hypergeometric functions in Feynman integral evaluation, they can also be used whenever they appear in other branches of mathematical physics. To facilitate their practical use, we provide four packages: $\texttt{AppellF1.wl}$, $\texttt{AppellF3.wl}$, $\texttt{LauricellaFD.wl}$, and $\texttt{LauricellaSaranFS.wl}$ in $\textit{MATHEMATICA}$. These packages are applicable for generic as well as non-generic values of parameters, keeping in mind their utilities in the evaluation of the Feynman integrals. We explicitly present various physical applications of these packages in the context of Feynman integral evaluation and compare the results using other means as well. Various $\textit{MATHEMATICA}$ notebooks demonstrating different numerical results are also provided along with this paper.
0907.1923
Michael Eides
Michael I. Eides and Valery A. Shelyuto
Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting in Muonium: Diagrams with Polarization Loops
8 pages, 10 figures. Editorial changes, results unchanged. Version published in Phys.Rev.Lett
Phys.Rev.Lett.103:133003,2009
10.1103/PhysRevLett.103.133003
UK/09-05
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by the diagrams with electron and muon vacuum polarizations. We calculate single-logarithmic and nonlogarithmic contributions of order $\alpha^3(m/M)E_F$ generated by gauge invariant sets of diagrams with electron and muon polarization insertions in the electron and muon factors. Combining the new contributions with our older results we present complete result for all three-loop radiative-recoil corrections generated by the diagrams with electron and muon polarization loops.
[ { "created": "Fri, 10 Jul 2009 22:09:00 GMT", "version": "v1" }, { "created": "Sat, 26 Sep 2009 04:14:10 GMT", "version": "v2" } ]
2010-01-26
[ [ "Eides", "Michael I.", "" ], [ "Shelyuto", "Valery A.", "" ] ]
We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by the diagrams with electron and muon vacuum polarizations. We calculate single-logarithmic and nonlogarithmic contributions of order $\alpha^3(m/M)E_F$ generated by gauge invariant sets of diagrams with electron and muon polarization insertions in the electron and muon factors. Combining the new contributions with our older results we present complete result for all three-loop radiative-recoil corrections generated by the diagrams with electron and muon polarization loops.
1102.0017
Guy D. Moore
Egang Lu, Guy D. Moore
The Bulk Viscosity of a Pion Gas
13 pages, two figures
Phys.Rev.C83:044901,2011
10.1103/PhysRevC.83.044901
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the bulk viscosity of a gas of pions at temperatures below the QCD crossover temperature, for the physical value of pion mass, to lowest order in chiral perturbation theory. Bulk viscosity is controlled by number-changing processes which become exponentially slow at low temperatures when the pions become exponentially dilute, leading to an exponentially large bulk viscosity zeta ~ (F_0^8/m_\pi^5) exp(2m_\pi/T), where F_0 = 93 MeV is the pion decay constant.
[ { "created": "Mon, 31 Jan 2011 21:31:03 GMT", "version": "v1" } ]
2011-07-19
[ [ "Lu", "Egang", "" ], [ "Moore", "Guy D.", "" ] ]
We compute the bulk viscosity of a gas of pions at temperatures below the QCD crossover temperature, for the physical value of pion mass, to lowest order in chiral perturbation theory. Bulk viscosity is controlled by number-changing processes which become exponentially slow at low temperatures when the pions become exponentially dilute, leading to an exponentially large bulk viscosity zeta ~ (F_0^8/m_\pi^5) exp(2m_\pi/T), where F_0 = 93 MeV is the pion decay constant.
hep-ph/9602381
Peter White
B. de Carlos (Sussex) and P.L. White (Oxford)
R-parity Violation Effects through Soft Supersymmetry Breaking Terms and the Renormalisation Group
41 pages plain LaTeX, 15 figures all uuencoded and gzipped (typos fixed and trivial changes ready for Phys. Rev. D)
Phys.Rev.D54:3427-3446,1996
10.1103/PhysRevD.54.3427
SUSX-TH/96-003, OUTP-96-01P, IEM-FT-125/96
hep-ph
null
We present full renormalisation group equations for the MSSM with R-parity violation, including all soft supersymmetry breaking terms. The inclusion of dimensionless R-parity violating couplings can generate many possible low energy effects through the generation of off-diagonal soft masses violating lepton and quark flavour, and through the generation of lepton-Higgs mixing. We discuss the relation between the weak and unification scale R-parity violation and study the effects on neutrino mass generation and $\mu\to e\gamma$.
[ { "created": "Fri, 23 Feb 1996 12:43:18 GMT", "version": "v1" }, { "created": "Tue, 4 Jun 1996 16:49:38 GMT", "version": "v2" } ]
2009-10-29
[ [ "de Carlos", "B.", "", "Sussex" ], [ "White", "P. L.", "", "Oxford" ] ]
We present full renormalisation group equations for the MSSM with R-parity violation, including all soft supersymmetry breaking terms. The inclusion of dimensionless R-parity violating couplings can generate many possible low energy effects through the generation of off-diagonal soft masses violating lepton and quark flavour, and through the generation of lepton-Higgs mixing. We discuss the relation between the weak and unification scale R-parity violation and study the effects on neutrino mass generation and $\mu\to e\gamma$.
2312.13882
Ricardo Aguirre
R. M. Aguirre
Effects of the anomalous magnetic moments of the quarks on the neutral pion properties within a SU(2) Nambu-Jona Lasinio model
8 figures
The European Physical Journal A 57, 166 (2021)
10.1140/epja/s10050-021-00480-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The properties of the neutral pion in quark matter under the influence of an external magnetic field are studied. The effects of the anomalous magnetic moments (AMM) of the quarks at finite density is considered. The inclusion of the AMM into the NJL model gives rise to additional magnetic effects. In particular the Dirac sea produce new divergences in the vacuum contributions, which depend explicitly on the magnetic field. An improper treatment of these contributions is the source of unphysical results, as emphasized in recent investigations. The pion polarization function is evaluated in the random phase approximation using analytic regularization and a subtraction scheme to deal with such divergencies. This procedure is combined with the standard three momentum cutoff, and reduces to it for vanishing magnetic intensity. The pion mass and coupling constant are evaluated for a wide range of magnetic intensity and baryonic density.
[ { "created": "Thu, 21 Dec 2023 14:27:25 GMT", "version": "v1" } ]
2023-12-22
[ [ "Aguirre", "R. M.", "" ] ]
The properties of the neutral pion in quark matter under the influence of an external magnetic field are studied. The effects of the anomalous magnetic moments (AMM) of the quarks at finite density is considered. The inclusion of the AMM into the NJL model gives rise to additional magnetic effects. In particular the Dirac sea produce new divergences in the vacuum contributions, which depend explicitly on the magnetic field. An improper treatment of these contributions is the source of unphysical results, as emphasized in recent investigations. The pion polarization function is evaluated in the random phase approximation using analytic regularization and a subtraction scheme to deal with such divergencies. This procedure is combined with the standard three momentum cutoff, and reduces to it for vanishing magnetic intensity. The pion mass and coupling constant are evaluated for a wide range of magnetic intensity and baryonic density.
hep-ph/9711356
Moultaka Gilbert
Christophe Le Mouel and Gilbert Moultaka
Novel Electroweak Symmetry Breaking Conditions From Quantum Effects In The MSSM
Latex, 45 pages, 5 figures
Nucl.Phys. B518 (1998) 3-36
10.1016/S0550-3213(98)00030-3
PM/97-26
hep-ph
null
We present, in the context of the Minimal Supersymmetric Standard Model, a detailed one-loop analytic study of the minimization conditions of the effective potential in the Higgs sector. Special emphasis is put on the role played by $Str M^4$ in the determination of the electroweak symmetry breaking conditions, where first and second order derivatives of the effective potential are systematically taken into account. Novel, necessary (and sufficient in the Higgs sector) model-independent constraints, are thus obtained analytically, leading to new theoretical lower and upper bounds on $\tan \beta$. Although fully model-independent, these bounds are found to be much more restrictive than the existing model-dependent ones! A first illustration is given in the context of a SUGRA-GUT motivated scenario.
[ { "created": "Mon, 17 Nov 1997 21:28:36 GMT", "version": "v1" } ]
2009-10-30
[ [ "Mouel", "Christophe Le", "" ], [ "Moultaka", "Gilbert", "" ] ]
We present, in the context of the Minimal Supersymmetric Standard Model, a detailed one-loop analytic study of the minimization conditions of the effective potential in the Higgs sector. Special emphasis is put on the role played by $Str M^4$ in the determination of the electroweak symmetry breaking conditions, where first and second order derivatives of the effective potential are systematically taken into account. Novel, necessary (and sufficient in the Higgs sector) model-independent constraints, are thus obtained analytically, leading to new theoretical lower and upper bounds on $\tan \beta$. Although fully model-independent, these bounds are found to be much more restrictive than the existing model-dependent ones! A first illustration is given in the context of a SUGRA-GUT motivated scenario.
1603.09553
Jean Cleymans
H. Oeschler, J. Cleymans, B. Hippolyte, K. Redlich, N. Sharma
Thermal Model Description of Collisions of Small Nuclei
8 pages, 4 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dependence of particle production on the size of the colliding nuclei is analysed in terms of the thermal model using the canonical ensemble. The concept of strangeness correlation in clusters of sub-volume $V_c$ is used to account for the suppression of strangeness. A systematic analysis is presented of the predictions of the thermal model for particle production in collisions of small nuclei. The pattern of the maxima of strange-particles-to-pion ratios as a function of beam energy is quite special, as they do not occur at the same beam energy and are sensitive to system size. In particular, the $\Lambda/\pi^+$ ratio shows a clear maximum even for small systems while the maximum in the K$^+/\pi^+$ ratio is less pronounced
[ { "created": "Thu, 31 Mar 2016 12:16:04 GMT", "version": "v1" }, { "created": "Wed, 8 Feb 2017 16:38:43 GMT", "version": "v2" } ]
2017-02-09
[ [ "Oeschler", "H.", "" ], [ "Cleymans", "J.", "" ], [ "Hippolyte", "B.", "" ], [ "Redlich", "K.", "" ], [ "Sharma", "N.", "" ] ]
The dependence of particle production on the size of the colliding nuclei is analysed in terms of the thermal model using the canonical ensemble. The concept of strangeness correlation in clusters of sub-volume $V_c$ is used to account for the suppression of strangeness. A systematic analysis is presented of the predictions of the thermal model for particle production in collisions of small nuclei. The pattern of the maxima of strange-particles-to-pion ratios as a function of beam energy is quite special, as they do not occur at the same beam energy and are sensitive to system size. In particular, the $\Lambda/\pi^+$ ratio shows a clear maximum even for small systems while the maximum in the K$^+/\pi^+$ ratio is less pronounced
hep-ph/0309112
Zhi-Zhong Xing
Zhi-zhong Xing, He Zhang
Complete Parameter Space of Quark Mass Matrices with Four Texture Zeros
RevTex 10 pages (3 PS figures included)
J.Phys.G30:129-136,2004
10.1088/0954-3899/30/2/011
null
hep-ph
null
The full parameter space of Hermitian quark mass matrices with four texture zeros is explored by using current experimental data. We find that all ten free parameters of the four-zero quark mass matrices can well be constrained. In particular, only one of the two phase parameters plays an important role in CP violation. The structural features of this specific pattern of quark mass matrices are also discussed in detail.
[ { "created": "Wed, 10 Sep 2003 14:26:35 GMT", "version": "v1" } ]
2008-11-26
[ [ "Xing", "Zhi-zhong", "" ], [ "Zhang", "He", "" ] ]
The full parameter space of Hermitian quark mass matrices with four texture zeros is explored by using current experimental data. We find that all ten free parameters of the four-zero quark mass matrices can well be constrained. In particular, only one of the two phase parameters plays an important role in CP violation. The structural features of this specific pattern of quark mass matrices are also discussed in detail.
1302.0624
Jarah Evslin
Emilio Ciuffoli, Jarah Evslin and Xinmin Zhang
The Neutrino Mass Hierarchy from Nuclear Reactor Experiments
12 pages, v3: +backgrounds, energy response and other challenges
Phys. Rev. D. 88, 033017 (2013)
10.1103/PhysRevD.88.033017
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
10 years from now reactor neutrino experiments will attempt to determine which neutrino mass eigenstate is the most massive. In this letter we present the results of more than seven million detailed simulations of such experiments, studying the dependence of the probability of successfully determining the mass hierarchy upon the analysis method, the neutrino mass matrix parameters, reactor flux models, geoneutrinos and, in particular, combinations of baselines. We show that a recently reported spurious dependence of the data analysis upon the high energy tail of the reactor spectrum can be removed by using a weighted Fourier transform. We determine the optimal baselines and corresponding detector locations. For most values of the CP-violating, leptonic Dirac phase delta, a degeneracy prevents NOvA and T2K from determining either delta or the hierarchy. We determine the confidence with which a reactor experiment can determine the hierarchy, breaking the degeneracy.
[ { "created": "Mon, 4 Feb 2013 09:24:54 GMT", "version": "v1" }, { "created": "Tue, 26 Mar 2013 06:31:51 GMT", "version": "v2" }, { "created": "Wed, 14 Aug 2013 17:24:37 GMT", "version": "v3" } ]
2013-09-16
[ [ "Ciuffoli", "Emilio", "" ], [ "Evslin", "Jarah", "" ], [ "Zhang", "Xinmin", "" ] ]
10 years from now reactor neutrino experiments will attempt to determine which neutrino mass eigenstate is the most massive. In this letter we present the results of more than seven million detailed simulations of such experiments, studying the dependence of the probability of successfully determining the mass hierarchy upon the analysis method, the neutrino mass matrix parameters, reactor flux models, geoneutrinos and, in particular, combinations of baselines. We show that a recently reported spurious dependence of the data analysis upon the high energy tail of the reactor spectrum can be removed by using a weighted Fourier transform. We determine the optimal baselines and corresponding detector locations. For most values of the CP-violating, leptonic Dirac phase delta, a degeneracy prevents NOvA and T2K from determining either delta or the hierarchy. We determine the confidence with which a reactor experiment can determine the hierarchy, breaking the degeneracy.
1207.5401
Francois Gelis
K. Dusling, T. Epelbaum, F. Gelis, R. Venugopalan
Initial state and thermalization
4 pages, 9 figures, talk given by FG at Hard Probes 2012 (may 27th - june 1st, 2012, Cagliari, Italy)
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report recent results on the role of instabilities in the isotropization and thermalization of a longitudinally expanding system of quantum fields.
[ { "created": "Mon, 23 Jul 2012 14:17:05 GMT", "version": "v1" }, { "created": "Fri, 5 Oct 2012 11:58:59 GMT", "version": "v2" } ]
2012-10-08
[ [ "Dusling", "K.", "" ], [ "Epelbaum", "T.", "" ], [ "Gelis", "F.", "" ], [ "Venugopalan", "R.", "" ] ]
We report recent results on the role of instabilities in the isotropization and thermalization of a longitudinally expanding system of quantum fields.
2012.14013
Duygu Yildirim Yilmaz
E. Cincioglu, A. Ozpineci, D. Yildirim Yilmaz
The effects of charmonium on the properties of the $1^{++}$ hidden charm poles in effective field theory
24 pages, 2 figures
Nucl.Phys.A 1014 (2021) 122259
10.1016/j.nuclphysa.2021.122259
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this study, the properties of the $J^{PC}=1^{++}$ hidden charm poles are analyzed under the variation of the bare 2P charmonium mass within the effective field theory proposed in Ref.[1]. The main focus of the current work is on the pole trajectory of the $\chi_{c1}(2P)$ charmonium dressed by the $D \bar{D}^*$ meson loops. It is shown that the trajectories of the pole change radically for values of the bare charmonium mass above a certain value and also depending on how close the pole is to the threshold.
[ { "created": "Sun, 27 Dec 2020 21:10:42 GMT", "version": "v1" }, { "created": "Sat, 7 Aug 2021 07:31:57 GMT", "version": "v2" } ]
2021-08-18
[ [ "Cincioglu", "E.", "" ], [ "Ozpineci", "A.", "" ], [ "Yilmaz", "D. Yildirim", "" ] ]
In this study, the properties of the $J^{PC}=1^{++}$ hidden charm poles are analyzed under the variation of the bare 2P charmonium mass within the effective field theory proposed in Ref.[1]. The main focus of the current work is on the pole trajectory of the $\chi_{c1}(2P)$ charmonium dressed by the $D \bar{D}^*$ meson loops. It is shown that the trajectories of the pole change radically for values of the bare charmonium mass above a certain value and also depending on how close the pole is to the threshold.
hep-ph/0605052
Jens Erler
Jens Erler and Genaro Toledo Sanchez
Upper Bound on the Hadronic Light-by-Light Contribution to the Muon g-2
4 pages; 2 references added, some changes in text; final version
Phys.Rev.Lett. 97 (2006) 161801
10.1103/PhysRevLett.97.161801
null
hep-ph hep-ex
null
There are indications that hadronic loops in some electroweak observables are almost saturated by parton level effects. Taking this as the hypothesis for this work, we propose a genuine parton level estimate of the hadronic light-by-light contribution to the anomalous magnetic moment of the muon, a_mu (LBL,had). Our quark mass definitions and values are motivated in detail, and the simplicity of our approach allows for a transparent error estimate. For infinitely heavy quarks our treatment is exact, while for asymptotically small quark masses a_mu (LBL,had) is overestimated. Interpolating, this suggests quoting an upper bound. We obtain a_mu (LBL,had) < 1.59 10^-9 (95% CL).
[ { "created": "Fri, 5 May 2006 17:04:09 GMT", "version": "v1" }, { "created": "Fri, 13 Oct 2006 23:59:05 GMT", "version": "v2" } ]
2009-11-11
[ [ "Erler", "Jens", "" ], [ "Sanchez", "Genaro Toledo", "" ] ]
There are indications that hadronic loops in some electroweak observables are almost saturated by parton level effects. Taking this as the hypothesis for this work, we propose a genuine parton level estimate of the hadronic light-by-light contribution to the anomalous magnetic moment of the muon, a_mu (LBL,had). Our quark mass definitions and values are motivated in detail, and the simplicity of our approach allows for a transparent error estimate. For infinitely heavy quarks our treatment is exact, while for asymptotically small quark masses a_mu (LBL,had) is overestimated. Interpolating, this suggests quoting an upper bound. We obtain a_mu (LBL,had) < 1.59 10^-9 (95% CL).
1202.2346
Girma Hailu
Girma Hailu
Glueball Masses from Linearly Confining Supergravity
11 pages
Phys.Rev. D85 (2012) 106008
10.1103/PhysRevD.85.106008
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mass spectrum of 0++ glueballs is produced using a dual supergravity theory we proposed for pure N=1 SU(N) gauge theory in four dimensions in the large N limit in the IR. The glueball states are expressed in terms of Whittaker functions. The spectrum is discrete and a function whose roots give the masses is written. The ratios of the masses are independent of the parameters of the theory and comparison to recent non-supersymmetric large N lattice QCD data available for the lowest three states shows agreement to within five percent.
[ { "created": "Fri, 10 Feb 2012 20:56:50 GMT", "version": "v1" } ]
2013-05-30
[ [ "Hailu", "Girma", "" ] ]
Mass spectrum of 0++ glueballs is produced using a dual supergravity theory we proposed for pure N=1 SU(N) gauge theory in four dimensions in the large N limit in the IR. The glueball states are expressed in terms of Whittaker functions. The spectrum is discrete and a function whose roots give the masses is written. The ratios of the masses are independent of the parameters of the theory and comparison to recent non-supersymmetric large N lattice QCD data available for the lowest three states shows agreement to within five percent.
2111.03582
Armando Bermudez Martinez
Armando Bermudez Martinez, Luis I. Estevez Banos, Hannes Jung, Jindrich Lidrych, Mikel Mendizabal, Sara Taheri Monfared, Qun Wang and Heng Yang
Application of TMD parton showers obtained with the Parton Branching approach to Drell Yan + jets production
6 pages, 3 figures, conference paper
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Calculations of Drell-Yan (DY) production at next-to-leading (NLO) order have been combined with Transverse Momentum Dependent (TMD) distributions obtained with the Parton Branching (PB). The predictions show a remarkable agreement with DY measurement from E605 experiment, consistent with previous results we obtained for R209, PHENIX, CMS and ATLAS experiments. We also present predictions for Z+jet measurements showing the importance of TMD parton shower contributions to the jet multiplicity. We show that PB-TMD parton density and the corresponding PB-TMD parton shower can be combined with leading-order (LO) matrix element using the newly developed TMD merging algorithm to obtain a very good description of measurements over a wide kinematic range.
[ { "created": "Fri, 5 Nov 2021 16:03:37 GMT", "version": "v1" } ]
2021-11-08
[ [ "Martinez", "Armando Bermudez", "" ], [ "Banos", "Luis I. Estevez", "" ], [ "Jung", "Hannes", "" ], [ "Lidrych", "Jindrich", "" ], [ "Mendizabal", "Mikel", "" ], [ "Monfared", "Sara Taheri", "" ], [ "Wang", "Qun", "" ], [ "Yang", "Heng", "" ] ]
Calculations of Drell-Yan (DY) production at next-to-leading (NLO) order have been combined with Transverse Momentum Dependent (TMD) distributions obtained with the Parton Branching (PB). The predictions show a remarkable agreement with DY measurement from E605 experiment, consistent with previous results we obtained for R209, PHENIX, CMS and ATLAS experiments. We also present predictions for Z+jet measurements showing the importance of TMD parton shower contributions to the jet multiplicity. We show that PB-TMD parton density and the corresponding PB-TMD parton shower can be combined with leading-order (LO) matrix element using the newly developed TMD merging algorithm to obtain a very good description of measurements over a wide kinematic range.
2401.14229
Liliana Apolin\'ario
Liliana Apolin\'ario, Pablo Guerrero-Rodr\'iguez, Korinna Zapp
Exploring the time axis within medium-modified jets
12 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this manuscript, we illustrate how to use the newly proposed $\tau$ re-clustering algorithm to select jets with different degrees of quenching without biasing their initial transverse momentum spectrum. Our study is based on Z+jet simulated events using the JEWEL Monte Carlo event generator to account for jet quenching effects. We apply the $\tau$ re-clustering algorithm to extract a proxy for a time axis (formation time) within the evolving medium. This information allows us to label jets according to their fragmentation pattern and select populations with enhanced sensitivity to quenching effects. Our results illustrate the potential of jets as precision tools for QGP tomography. Further, we show that the discussed method minimizes the biases stemming from $p_{T}$-, $dR$- or mass-based jet selection.
[ { "created": "Thu, 25 Jan 2024 15:15:30 GMT", "version": "v1" } ]
2024-01-26
[ [ "Apolinário", "Liliana", "" ], [ "Guerrero-Rodríguez", "Pablo", "" ], [ "Zapp", "Korinna", "" ] ]
In this manuscript, we illustrate how to use the newly proposed $\tau$ re-clustering algorithm to select jets with different degrees of quenching without biasing their initial transverse momentum spectrum. Our study is based on Z+jet simulated events using the JEWEL Monte Carlo event generator to account for jet quenching effects. We apply the $\tau$ re-clustering algorithm to extract a proxy for a time axis (formation time) within the evolving medium. This information allows us to label jets according to their fragmentation pattern and select populations with enhanced sensitivity to quenching effects. Our results illustrate the potential of jets as precision tools for QGP tomography. Further, we show that the discussed method minimizes the biases stemming from $p_{T}$-, $dR$- or mass-based jet selection.
1112.4405
Daniel de Florian
Stefano Catani, Daniel de Florian and German Rodrigo
Space-like (vs. time-like) collinear limits in QCD: is factorization violated?
81 pages, 5 figures, typos corrected in the text, few comments added and inclusion of NOTE ADDED on recent developments
null
10.1007/JHEP07(2012)026
LPN11-94; IFIC/11-72; ZU-TH 27/11
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the singular behaviour of QCD scattering amplitudes in kinematical configurations where two or more momenta of the external partons become collinear. At the tree level, this behaviour is known to be controlled by factorization formulae in which the singular collinear factor is universal (process independent). We show that this strict (process-independent) factorization is not valid at one-loop and higher-loop orders in the case of the collinear limit in space-like regions (e.g., collinear radiation from initial-state partons). We introduce a generalized version of all-order collinear factorization, in which the space-like singular factors retain some dependence on the momentum and colour charge of the non-collinear partons. We present explicit results on one-loop and two-loop amplitudes for both the two-parton and multiparton collinear limits. At the level of square amplitudes and, more generally, cross sections in hadron--hadron collisions, the violation of strict collinear factorization has implications on the non-abelian structure of logarithmically-enhanced terms in perturbative calculations (starting from the next-to-next-to-leading order) and on various factorization issues of mass singularities (starting from the next-to-next-to-next-to-leading order).
[ { "created": "Mon, 19 Dec 2011 17:04:20 GMT", "version": "v1" }, { "created": "Thu, 28 Jun 2012 16:49:22 GMT", "version": "v2" } ]
2015-06-03
[ [ "Catani", "Stefano", "" ], [ "de Florian", "Daniel", "" ], [ "Rodrigo", "German", "" ] ]
We consider the singular behaviour of QCD scattering amplitudes in kinematical configurations where two or more momenta of the external partons become collinear. At the tree level, this behaviour is known to be controlled by factorization formulae in which the singular collinear factor is universal (process independent). We show that this strict (process-independent) factorization is not valid at one-loop and higher-loop orders in the case of the collinear limit in space-like regions (e.g., collinear radiation from initial-state partons). We introduce a generalized version of all-order collinear factorization, in which the space-like singular factors retain some dependence on the momentum and colour charge of the non-collinear partons. We present explicit results on one-loop and two-loop amplitudes for both the two-parton and multiparton collinear limits. At the level of square amplitudes and, more generally, cross sections in hadron--hadron collisions, the violation of strict collinear factorization has implications on the non-abelian structure of logarithmically-enhanced terms in perturbative calculations (starting from the next-to-next-to-leading order) and on various factorization issues of mass singularities (starting from the next-to-next-to-next-to-leading order).
hep-ph/9604330
Stefan Herrlich
Stefan Herrlich (DESY - IfH Zeuthen), Ulrich Nierste (TU Munich)
The Complete |Delta S|=2 Hamiltonian in the Next-To-Leading Order
68 pages, requires LaTeX2e and the standard LaTeX-packages epsf.sty, rotate.sty, a4.sty, subeqn.sty, cite.sty, array.sty, dcolumn.sty; Figures are submitted as a seperate tar.gz-file. A complete PostScript version may be obtained from ftp://feynman.t30.physik.tu-muenchen.de/pub/preprints/tum-86-96.ps.gz or ftp://feynman.t30.physik.tu-muenchen.de/pub/preprints/tum-86-96.ps2.gz (scaled down and rotated version to print two pages on one sheet of paper). Source available at ftp://feynman.t30.physik.tu-muenchen.de/pub/preprints/tum-86-96.tar.gz
Nucl.Phys. B476 (1996) 27-88
10.1016/0550-3213(96)00324-0
null
hep-ph
null
We present the complete next-to-leading order short-distance QCD corrections to the effective \dstwo -hamiltonian in the Standard Model. The calculation of the coefficient $\eta_3$ is described in great detail. It involves the two-loop mixing of bilocal structures composed of two \dsone\ operators into \dstwo\ operators. The next-to-leading order corrections enhance $\eta_3$ by 27\% to $\eta_3=0.47 \errorpm{+0.03}{-0.04}$ thereby affecting the phenomenology of $\epsilon_K$ sizeably. $\eta_3$ depends on the physical input parameters $m_t$, $m_c$ and $\laMSb$ only weakly. The quoted error stems from renormalization scale dependences, which have reduced compared to the old leading log result. The known calculation of $\eta_1$ and $\eta_2$ is repeated in order to compare the structure of the three QCD coefficients. We further discuss some field theoretical aspects of the calculation such as the renormalization group equation for Green's functions with two operator insertions and the renormalization scheme dependence caused by the presence of evanescent operators.
[ { "created": "Tue, 16 Apr 1996 15:26:37 GMT", "version": "v1" } ]
2009-10-28
[ [ "Herrlich", "Stefan", "", "DESY - IfH Zeuthen" ], [ "Nierste", "Ulrich", "", "TU Munich" ] ]
We present the complete next-to-leading order short-distance QCD corrections to the effective \dstwo -hamiltonian in the Standard Model. The calculation of the coefficient $\eta_3$ is described in great detail. It involves the two-loop mixing of bilocal structures composed of two \dsone\ operators into \dstwo\ operators. The next-to-leading order corrections enhance $\eta_3$ by 27\% to $\eta_3=0.47 \errorpm{+0.03}{-0.04}$ thereby affecting the phenomenology of $\epsilon_K$ sizeably. $\eta_3$ depends on the physical input parameters $m_t$, $m_c$ and $\laMSb$ only weakly. The quoted error stems from renormalization scale dependences, which have reduced compared to the old leading log result. The known calculation of $\eta_1$ and $\eta_2$ is repeated in order to compare the structure of the three QCD coefficients. We further discuss some field theoretical aspects of the calculation such as the renormalization group equation for Green's functions with two operator insertions and the renormalization scheme dependence caused by the presence of evanescent operators.
1706.08510
James Cline
James M. Cline, Jorge Martin Camalich
$B$ decay anomalies from nonabelian local horizontal symmetry
13 pages, 4 figures; v2: minor corrections and improvements, references added; v3: corrected fig.1, published version
Phys. Rev. D 96, 055036 (2017)
10.1103/PhysRevD.96.055036
CERN-TH-2017-136
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent anomalies in $B\to K^{(*)}\ell\ell$ meson decays are consistent with exchange of a heavy $Z'$ vector boson. Here we try to connect such new physics to understanding the origin of flavor, by gauging generation number. Phenomenological and theoretical considerations suggest that the smallest viable flavor symmetry (not including any extra U(1) factors) is chiral ${\rm SU(3)}_L\times{\rm SU(3)}_R$, which acts only on generation indices and does not distinguish between quarks and leptons. Spontaneous breaking of the symmetry gives rise to the standard model Yukawa matrices, and masses for the 16 $Z'$-like gauge bosons, one of which is presumed to be light enough to explain the $B\to K^{(*)}\ell\ell$ anomalies. We perform a bottom-up study of this framework, showing that it is highly constrained by LHC dilepton searches, meson mixing, $Z$ decays and CKM unitarity. Similar anomalies are predicted for semileptonic decays of $B$ to lighter mesons, with excesses in the $ee,\tau\tau$ channels and deficits in $\mu\mu$, but no deviation in $\nu\nu$. The lightest $Z'$ mass is $\lesssim 6\,$TeV if the gauge coupling is $\lesssim 1$.
[ { "created": "Mon, 26 Jun 2017 17:59:50 GMT", "version": "v1" }, { "created": "Sun, 16 Jul 2017 01:30:33 GMT", "version": "v2" }, { "created": "Fri, 13 Oct 2017 08:35:58 GMT", "version": "v3" } ]
2017-10-16
[ [ "Cline", "James M.", "" ], [ "Camalich", "Jorge Martin", "" ] ]
Recent anomalies in $B\to K^{(*)}\ell\ell$ meson decays are consistent with exchange of a heavy $Z'$ vector boson. Here we try to connect such new physics to understanding the origin of flavor, by gauging generation number. Phenomenological and theoretical considerations suggest that the smallest viable flavor symmetry (not including any extra U(1) factors) is chiral ${\rm SU(3)}_L\times{\rm SU(3)}_R$, which acts only on generation indices and does not distinguish between quarks and leptons. Spontaneous breaking of the symmetry gives rise to the standard model Yukawa matrices, and masses for the 16 $Z'$-like gauge bosons, one of which is presumed to be light enough to explain the $B\to K^{(*)}\ell\ell$ anomalies. We perform a bottom-up study of this framework, showing that it is highly constrained by LHC dilepton searches, meson mixing, $Z$ decays and CKM unitarity. Similar anomalies are predicted for semileptonic decays of $B$ to lighter mesons, with excesses in the $ee,\tau\tau$ channels and deficits in $\mu\mu$, but no deviation in $\nu\nu$. The lightest $Z'$ mass is $\lesssim 6\,$TeV if the gauge coupling is $\lesssim 1$.
hep-ph/9805491
Valentin Kuznetsov
Elena N. Bukina, Vladimir M. Dubovik (JINR, Russia) and Valentin E. Kuznetsov (CERN, Switzerland and JINR, Russia)
Transition Radiation of the Neutrino Toroid Dipole Moment
8 pages and 4 EPS-figures included. use prd.sty, preprint.sty, aps.sty and epsfig.sty (RevTeX is used)
Phys.Lett. B435 (1998) 134-138
10.1016/S0370-2693(98)00776-X
null
hep-ph
null
We discuss the transition radiation of a neutrino induced by its toroid dipole moment ($\tau$) when crossing the interface between two different media with different refraction indices. A neutrino of 1 MeV energy emits approximately $10^{-40}$ keV at $\tau=e\sqrt{2}G_F/\pi^2$. This effect depends very slightly on the neutrino mass and has a finite value in the massless limit.
[ { "created": "Thu, 28 May 1998 09:12:31 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bukina", "Elena N.", "", "JINR, Russia" ], [ "Dubovik", "Vladimir M.", "", "JINR, Russia" ], [ "Kuznetsov", "Valentin E.", "", "CERN, Switzerland and JINR, Russia" ] ]
We discuss the transition radiation of a neutrino induced by its toroid dipole moment ($\tau$) when crossing the interface between two different media with different refraction indices. A neutrino of 1 MeV energy emits approximately $10^{-40}$ keV at $\tau=e\sqrt{2}G_F/\pi^2$. This effect depends very slightly on the neutrino mass and has a finite value in the massless limit.
hep-ph/0011154
Dr. M. Kirchbach
M. Kirchbach
Degeneracy Symmetry Of Baryon Spectra
Invited talk, to be published in Proc. XVII European Conference on ``Few-Body Problems in Physics'', Evora (Portugal), Sept. 11-16, 2000. 10 pages LaTeX2e with 4 figures
Nucl.Phys. A689 (2001) 157-166
10.1016/S0375-9474(01)00830-2
null
hep-ph
null
We present a data-supported new interpretation of the Rarita-Schwinger fields which reveals a well-defined pattern in the masses, spins, and parities of the N-, Delta -, and Lambda -hyperon excitations and which allows to probe the scale of the chiral phase transition for baryons. The degeneracy symmetry of the baryonic spectra emerges to be Isospin(x)Space- Time.
[ { "created": "Sat, 11 Nov 2000 21:37:40 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kirchbach", "M.", "" ] ]
We present a data-supported new interpretation of the Rarita-Schwinger fields which reveals a well-defined pattern in the masses, spins, and parities of the N-, Delta -, and Lambda -hyperon excitations and which allows to probe the scale of the chiral phase transition for baryons. The degeneracy symmetry of the baryonic spectra emerges to be Isospin(x)Space- Time.
2010.12579
Yury Bystritskiy
A.G. Aleksejevs, S.G. Barkanova, Yu.M. Bystritskiy, V.A. Zykunov
One-Loop Electroweak Radiative Corrections to Bhabha Scattering in the Belle II Experiment
6 pages, 9 figures, proceedings for International Bogolyubov Conference Problems of Theoretical and Mathematical Physics (2019)
Phys.Part.Nucl. 51 (2020) 4, 645-650
10.1134/S106377962004005X
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model radiative corrections to the Bhabha scattering process are considered within the one-loop approximation. Both virtual corrections and corrections for the real photon emission are taken into consideration. The calculation was performed at the energy assumed at the Belle II (Japan) facility.
[ { "created": "Fri, 23 Oct 2020 08:13:15 GMT", "version": "v1" } ]
2020-10-27
[ [ "Aleksejevs", "A. G.", "" ], [ "Barkanova", "S. G.", "" ], [ "Bystritskiy", "Yu. M.", "" ], [ "Zykunov", "V. A.", "" ] ]
The Standard Model radiative corrections to the Bhabha scattering process are considered within the one-loop approximation. Both virtual corrections and corrections for the real photon emission are taken into consideration. The calculation was performed at the energy assumed at the Belle II (Japan) facility.
2301.10811
Omar Medina
Cesar Bonilla, Johannes Herms, Omar Medina, Eduardo Peinado
Discrete dark matter mechanism as the source of neutrino mass scales
23 pages, 6 figures and 3 tables. v2: matches published version
JHEP 06 (2023) 078
10.1007/JHEP06(2023)078
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The hierarchy in scale between atmospheric and solar neutrino mass splittings is investigated through two distinct neutrino mass mechanisms, from tree- and one-loop-level contributions. We demonstrate that the minimal discrete dark matter mechanism contains the ingredients for explaining this hierarchy. This scenario is characterized by adding new RH neutrinos and scalar $SU(2)$-doublets to the Standard Model as triplet representations of an $A_4$ flavor symmetry. The $A_4$ symmetry breaking, which occurs at the electroweak scale, leads to a residual $\mathbb{Z}_2$ symmetry responsible for the dark matter stability and dictates the neutrino phenomenology. Finally, we show that to reproduce the neutrino mixing angles correctly it is necessary to violate CP in the scalar potential.
[ { "created": "Wed, 25 Jan 2023 20:05:31 GMT", "version": "v1" }, { "created": "Thu, 15 Jun 2023 16:32:58 GMT", "version": "v2" } ]
2023-06-16
[ [ "Bonilla", "Cesar", "" ], [ "Herms", "Johannes", "" ], [ "Medina", "Omar", "" ], [ "Peinado", "Eduardo", "" ] ]
The hierarchy in scale between atmospheric and solar neutrino mass splittings is investigated through two distinct neutrino mass mechanisms, from tree- and one-loop-level contributions. We demonstrate that the minimal discrete dark matter mechanism contains the ingredients for explaining this hierarchy. This scenario is characterized by adding new RH neutrinos and scalar $SU(2)$-doublets to the Standard Model as triplet representations of an $A_4$ flavor symmetry. The $A_4$ symmetry breaking, which occurs at the electroweak scale, leads to a residual $\mathbb{Z}_2$ symmetry responsible for the dark matter stability and dictates the neutrino phenomenology. Finally, we show that to reproduce the neutrino mixing angles correctly it is necessary to violate CP in the scalar potential.
1509.08720
Chris Kouvaris
Chris Kouvaris
Earth's Stopping Effect in Directional Dark Matter Detectors
9 pages, 5 figures
Phys. Rev. D 93, 035023 (2016)
10.1103/PhysRevD.93.035023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the stopping effect that results from interactions between dark matter and nuclei as the dark matter particles travel undergound towards the detector. Although this effect is negligible for heavy dark matter particles, there is parameter phase space where the underground interactions of the dark matter particles with the nuclei can create observable differences in the spectrum. Dark matter particles that arrive on the detector from below can have less energy from the ones arriving from above. These differences can be potentially detectable by upcoming directional detectors. This can unveil a large amount of information regarding the type and strength of interactions between nuclei and light dark matter candidates.
[ { "created": "Tue, 29 Sep 2015 12:42:51 GMT", "version": "v1" } ]
2016-03-02
[ [ "Kouvaris", "Chris", "" ] ]
We explore the stopping effect that results from interactions between dark matter and nuclei as the dark matter particles travel undergound towards the detector. Although this effect is negligible for heavy dark matter particles, there is parameter phase space where the underground interactions of the dark matter particles with the nuclei can create observable differences in the spectrum. Dark matter particles that arrive on the detector from below can have less energy from the ones arriving from above. These differences can be potentially detectable by upcoming directional detectors. This can unveil a large amount of information regarding the type and strength of interactions between nuclei and light dark matter candidates.
hep-ph/9806458
Un-Ki Yang
U.K. Yang and A. Bodek
Parton distributions at high x
7 pages, To be published in proceedings of the 6th International Workshop on Deep Inelastic Scattering and QCD, Brussels, Apr. 1998
null
null
UR-1518
hep-ph
null
We extract the ratio of the down (d) and up (u) parton distribution functions (PDF's) from the ratio of NMC deuteron and proton structure function F_2(d)/F_2(p), using corrections for nuclear binding effects in the deuteron, which are extracted from the nuclear dependence of SLAC F_2 data. Significant corrections to the d quark distribution in standard PDF's are required, especially at high x. The corrected d/u ratio is in agreement with the QCD prediction of 0.2 at x=1. The predictions for the recent CDF W asymmetry data using PDF's with the corrected d/u ratio give much better agreement at large rapidity. Using the updated d/u ratio and the most recent world average for alpha_s, we perform a NLO global fit to all DIS data for F_2 and R, and estimate the size of the higher twist contributions using both a renormalon model and an empirical model. We find that with the updated value of alpha_s, the magnitude of the higher twist terms is half the value of previous analysis. With the inclusion of target mass and higher twist corrections, the standard NLO PDF's with the updated d/u ratio describe the SLAC F_2 data up to x=1.0. When the analysis is repeated in NNLO, we find that the additional NNLO contributions to R account for most of the higher twist effects extracted in the NLO fit. The analysis in NNLO indicates that the higher twist effects in R, F_2 and xF_3 (e.g. GLS sum rule) are very small.
[ { "created": "Wed, 24 Jun 1998 00:03:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Yang", "U. K.", "" ], [ "Bodek", "A.", "" ] ]
We extract the ratio of the down (d) and up (u) parton distribution functions (PDF's) from the ratio of NMC deuteron and proton structure function F_2(d)/F_2(p), using corrections for nuclear binding effects in the deuteron, which are extracted from the nuclear dependence of SLAC F_2 data. Significant corrections to the d quark distribution in standard PDF's are required, especially at high x. The corrected d/u ratio is in agreement with the QCD prediction of 0.2 at x=1. The predictions for the recent CDF W asymmetry data using PDF's with the corrected d/u ratio give much better agreement at large rapidity. Using the updated d/u ratio and the most recent world average for alpha_s, we perform a NLO global fit to all DIS data for F_2 and R, and estimate the size of the higher twist contributions using both a renormalon model and an empirical model. We find that with the updated value of alpha_s, the magnitude of the higher twist terms is half the value of previous analysis. With the inclusion of target mass and higher twist corrections, the standard NLO PDF's with the updated d/u ratio describe the SLAC F_2 data up to x=1.0. When the analysis is repeated in NNLO, we find that the additional NNLO contributions to R account for most of the higher twist effects extracted in the NLO fit. The analysis in NNLO indicates that the higher twist effects in R, F_2 and xF_3 (e.g. GLS sum rule) are very small.
2305.12378
Mikhail Krivoruchenko
M. I. Krivoruchenko and F. Simkovic
Neutrino Mass Matrix in Neutrino-Related Processes
19 pages; two references, one footnote added, misprints removed
Physics of Atomic Nuclei, 2023, Vol. 86, No. 5, pp. 709 - 724
10.1134/S1063778823050253
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Techniques are developed for constructing amplitudes of neutrino-related processes in terms of the neutrino mass matrix, with no reference to the neutrino mixing matrix. The amplitudes of neutrino oscillations in vacuum and medium, quasi-elastic neutrino scattering, $\beta$ decays and double-$\beta$ decays are considered. The proposed approach makes extensive use of Frobenius covariants within the framework of Sylvester's theorem on matrix functions. The in-medium dispersion laws are found in terms of elementary functions for three flavors of Majorana neutrinos as an application of the developed formalism. The in-medium dispersion laws for Dirac neutrinos can be determined in the general case by searching for the roots of a polynomial of degree 6. In the rest frame of baryon matter, the minimum energy of both Majorana and Dirac neutrinos is achieved at a finite neutrino momentum. In such cases, Dirac neutrinos occupy a hollow Fermi sphere at zero temperature and low densities. Fitting experimental data in terms of the neutrino mass matrix can provide better statistical accuracy in determining the neutrino mass matrix compared to methods using the neutrino mixing matrix at intermediate stages.
[ { "created": "Sun, 21 May 2023 07:20:07 GMT", "version": "v1" }, { "created": "Wed, 6 Mar 2024 06:10:40 GMT", "version": "v2" } ]
2024-03-07
[ [ "Krivoruchenko", "M. I.", "" ], [ "Simkovic", "F.", "" ] ]
Techniques are developed for constructing amplitudes of neutrino-related processes in terms of the neutrino mass matrix, with no reference to the neutrino mixing matrix. The amplitudes of neutrino oscillations in vacuum and medium, quasi-elastic neutrino scattering, $\beta$ decays and double-$\beta$ decays are considered. The proposed approach makes extensive use of Frobenius covariants within the framework of Sylvester's theorem on matrix functions. The in-medium dispersion laws are found in terms of elementary functions for three flavors of Majorana neutrinos as an application of the developed formalism. The in-medium dispersion laws for Dirac neutrinos can be determined in the general case by searching for the roots of a polynomial of degree 6. In the rest frame of baryon matter, the minimum energy of both Majorana and Dirac neutrinos is achieved at a finite neutrino momentum. In such cases, Dirac neutrinos occupy a hollow Fermi sphere at zero temperature and low densities. Fitting experimental data in terms of the neutrino mass matrix can provide better statistical accuracy in determining the neutrino mass matrix compared to methods using the neutrino mixing matrix at intermediate stages.
1506.06949
Majid Hashemi
Majid Hashemi, Seyyed Mohammad Zebarjad, Hossein Bakhshalizadeh
The t-channel Charged Higgs Production in Single Top Events at LHC
null
Int. J. Theor. Phys. 55 (2016) 2405
10.1007/s10773-015-2878-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, the t-channel charged Higgs production at LHC is studied. Production process is a t-channel single top event with charged Higgs exchange. Therefore the signal is similar with Standard Model single top production in terms of the final state. In the first step, the signal cross section is calculated and compared to the other main production processes which are used for a heavy charged Higgs search at LHC, i.e., pp -> tbH- and pp -> H+ -> tb. In the next step, an event generation and analysis is applied on signal and background events, in order to estimate the signal significance. The signal cross section is typically smaller than the associated production (tbH-) and resonance production (tb) by a factor of 10-3 and ranges from 10 fb to 1 fb for charged Higgs mass from 200 to 500 GeV at tanbeta = 50. Due to the small cross section of signal events and large SM background, the signal significance is small even after a dedicated kinematic analysis and selection of events, however, tanbeta values above 120 can be excluded at an integrated luminosity of 3000 fb-1.
[ { "created": "Tue, 23 Jun 2015 11:26:52 GMT", "version": "v1" } ]
2016-04-27
[ [ "Hashemi", "Majid", "" ], [ "Zebarjad", "Seyyed Mohammad", "" ], [ "Bakhshalizadeh", "Hossein", "" ] ]
In this paper, the t-channel charged Higgs production at LHC is studied. Production process is a t-channel single top event with charged Higgs exchange. Therefore the signal is similar with Standard Model single top production in terms of the final state. In the first step, the signal cross section is calculated and compared to the other main production processes which are used for a heavy charged Higgs search at LHC, i.e., pp -> tbH- and pp -> H+ -> tb. In the next step, an event generation and analysis is applied on signal and background events, in order to estimate the signal significance. The signal cross section is typically smaller than the associated production (tbH-) and resonance production (tb) by a factor of 10-3 and ranges from 10 fb to 1 fb for charged Higgs mass from 200 to 500 GeV at tanbeta = 50. Due to the small cross section of signal events and large SM background, the signal significance is small even after a dedicated kinematic analysis and selection of events, however, tanbeta values above 120 can be excluded at an integrated luminosity of 3000 fb-1.
1108.3428
Raghavendra Hundi
Dilip Kumar Ghosh and R. S. Hundi
Neutrino masses along with fermion mass hierarchy
20 pages, the content on results and phenomenology have been expanded, a new section on UV completion of the model has been added and also some new references, this version has been accepted by Physical Review D
null
10.1103/PhysRevD.85.013005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently a new mechanism has been proposed to cure the problem of fermion mass hierarchy in the Standard Model (SM) model. In this scenario, all SM charged fermions other than top quark arise from higher dimensional operators involving the SM Higgs field. This model also predicted some interesting phenomenology of the Higgs boson. We generalize this model to accommodate neutrino masses (Dirac & Majorana) and also obtain the mixing pattern in the leptonic sector. To generate neutrino masses, we add extra three right handed neutrinos $(N_{iR})$ in this model.
[ { "created": "Wed, 17 Aug 2011 09:02:39 GMT", "version": "v1" }, { "created": "Mon, 12 Dec 2011 05:25:33 GMT", "version": "v2" } ]
2013-05-30
[ [ "Ghosh", "Dilip Kumar", "" ], [ "Hundi", "R. S.", "" ] ]
Recently a new mechanism has been proposed to cure the problem of fermion mass hierarchy in the Standard Model (SM) model. In this scenario, all SM charged fermions other than top quark arise from higher dimensional operators involving the SM Higgs field. This model also predicted some interesting phenomenology of the Higgs boson. We generalize this model to accommodate neutrino masses (Dirac & Majorana) and also obtain the mixing pattern in the leptonic sector. To generate neutrino masses, we add extra three right handed neutrinos $(N_{iR})$ in this model.
hep-ph/9811353
Nima Arkani Hamed
Nima Arkani-Hamed and Savas Dimopoulos
New origin for approximate symmetries from distant breaking in extra dimensions
29 pages, latex
Phys.Rev. D65 (2002) 052003
10.1103/PhysRevD.65.052003
SLAC-PUB-8008, SU-ITP-98/62
hep-ph hep-th
null
The recently proposed theories with TeV-scale quantum gravity remove the usual ultraviolet desert between $\sim 10^{3} - 10^{19}$ GeV where effective field theory ideas apply. Consequently, the success of the desert in explaining approximate symmetries is lost, and theories of flavor, neutrino masses, proton longevity or supersymmetry breaking, lose their usual habitat. In this paper we show that these ideas can find a new home in an infrared desert: the large space in the extra dimensions. The main idea is that symmetries are primordially exact on our brane, but are broken at O(1) on distant branes. This breaking is communicated to us in a distance-suppressed way by bulk messengers. We illustrate these ideas in a number of settings: 1) We construct theories for the fermion mass hierarchy which avoid large FCNC's. 2) We re-iterate that proton stability can arise if baryon number is gauged in the bulk. 3) We study experimental constraints on light gauge fields and scalars in the bulk. 4) We remark that the same ideas can be used to explain small neutrino masses, and hierarchical supersymmetry breaking. 5) We construct a theory with bulk technicolor, avoiding the difficulties with extended technicolor. There are also interesting experimental signals of these ideas: 1) Attractive or repulsive, isotope dependent sub-millimeter forces $\sim 10^6$ times gravitational strength, from the exchange of light bulk particles. 2) Novel Higgs decays to light generation fermions plus bulk scalars. 3) Collider production of bulk vector and scalar fields, leading to large $\gamma$ or jet+ missing energy signals.
[ { "created": "Mon, 16 Nov 1998 21:19:36 GMT", "version": "v1" } ]
2009-10-31
[ [ "Arkani-Hamed", "Nima", "" ], [ "Dimopoulos", "Savas", "" ] ]
The recently proposed theories with TeV-scale quantum gravity remove the usual ultraviolet desert between $\sim 10^{3} - 10^{19}$ GeV where effective field theory ideas apply. Consequently, the success of the desert in explaining approximate symmetries is lost, and theories of flavor, neutrino masses, proton longevity or supersymmetry breaking, lose their usual habitat. In this paper we show that these ideas can find a new home in an infrared desert: the large space in the extra dimensions. The main idea is that symmetries are primordially exact on our brane, but are broken at O(1) on distant branes. This breaking is communicated to us in a distance-suppressed way by bulk messengers. We illustrate these ideas in a number of settings: 1) We construct theories for the fermion mass hierarchy which avoid large FCNC's. 2) We re-iterate that proton stability can arise if baryon number is gauged in the bulk. 3) We study experimental constraints on light gauge fields and scalars in the bulk. 4) We remark that the same ideas can be used to explain small neutrino masses, and hierarchical supersymmetry breaking. 5) We construct a theory with bulk technicolor, avoiding the difficulties with extended technicolor. There are also interesting experimental signals of these ideas: 1) Attractive or repulsive, isotope dependent sub-millimeter forces $\sim 10^6$ times gravitational strength, from the exchange of light bulk particles. 2) Novel Higgs decays to light generation fermions plus bulk scalars. 3) Collider production of bulk vector and scalar fields, leading to large $\gamma$ or jet+ missing energy signals.