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1510.01598
Astrid Nathalie Hiller Blin
Astrid Hiller Blin, Tim Ledwig, Manuel Vicente Vacas
Neutral pion photoproduction on protons in fully covariant ChPT with Delta(1232) loop contributions
Proceedings to the 8th International Workshop on Chiral Dynamic 2015
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the neutral pion photoproduction at near-threshold energies in fully covariant chiral perturbation theory up to O(p^3). When including only nucleonic virtual states in the model, the convergence is too slow. Therefore we test the model when introducing the Delta(1232) resonance as an additional degree of freedom. Some low-energy constants were fitted, converging to values in good agreement with those expected from literature.
[ { "created": "Tue, 6 Oct 2015 14:41:56 GMT", "version": "v1" } ]
2015-10-07
[ [ "Blin", "Astrid Hiller", "" ], [ "Ledwig", "Tim", "" ], [ "Vacas", "Manuel Vicente", "" ] ]
We study the neutral pion photoproduction at near-threshold energies in fully covariant chiral perturbation theory up to O(p^3). When including only nucleonic virtual states in the model, the convergence is too slow. Therefore we test the model when introducing the Delta(1232) resonance as an additional degree of freedom. Some low-energy constants were fitted, converging to values in good agreement with those expected from literature.
2301.13633
Luis Hernandez
Alejandro Ayala, Aritra Bandyopadhyay, Ricardo L. S. Farias, Luis A. Hern\'andez and Jos\'e Luis Hern\'andez
QCD equation of state at finite isospin density from the linear sigma model with quarks: The cold case
11 pages and 7 figures. Expanded discussion, references and graphs added, conclusions unchanged
null
10.1103/PhysRevD.107.074027
null
hep-ph hep-lat nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
We use the two-flavor linear sigma model with quarks to study the phase structure of isospin asymmetric matter at zero temperature. The meson degrees of freedom provide the mean field chiral- and isospin-condensates on top of which we compute the effective potential accounting for constituent quark fluctuations at one-loop order. Using the renormalizability of the model, we absorb the ultraviolet divergences into suitable counter-terms that are added respecting the original structure of the theory. These counter-terms are determined from the stability conditions which require the effective potential to have minima in the condensates directions at the classical values, as well as the transition from the non-condensed to the condensed phase to be smooth as a function of the isospin chemical potential. We use the model to study the evolution of the condensates as well as the pressure, energy and isospin densities and the sound velocity as functions of the isospin chemical potential. The approach does a good average description up to isospin chemical potentials values not too large as compared to the vacuum pion mass.
[ { "created": "Tue, 31 Jan 2023 13:48:31 GMT", "version": "v1" }, { "created": "Tue, 2 May 2023 02:05:21 GMT", "version": "v2" } ]
2023-05-03
[ [ "Ayala", "Alejandro", "" ], [ "Bandyopadhyay", "Aritra", "" ], [ "Farias", "Ricardo L. S.", "" ], [ "Hernández", "Luis A.", "" ], [ "Hernández", "José Luis", "" ] ]
We use the two-flavor linear sigma model with quarks to study the phase structure of isospin asymmetric matter at zero temperature. The meson degrees of freedom provide the mean field chiral- and isospin-condensates on top of which we compute the effective potential accounting for constituent quark fluctuations at one-loop order. Using the renormalizability of the model, we absorb the ultraviolet divergences into suitable counter-terms that are added respecting the original structure of the theory. These counter-terms are determined from the stability conditions which require the effective potential to have minima in the condensates directions at the classical values, as well as the transition from the non-condensed to the condensed phase to be smooth as a function of the isospin chemical potential. We use the model to study the evolution of the condensates as well as the pressure, energy and isospin densities and the sound velocity as functions of the isospin chemical potential. The approach does a good average description up to isospin chemical potentials values not too large as compared to the vacuum pion mass.
2310.01483
Benjamin Lillard
Benjamin Lillard
Wavelet-Harmonic Integration Methods
67 pages, 8 figures, 1 table, 5 appendices, 281092 wavelets
null
null
null
hep-ph astro-ph.IM math-ph math.MP nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new integration method drastically improves the efficiency of the dark matter direct detection calculation. In this work I introduce a complete, orthogonal basis of spherical wavelet-harmonic functions, designed for the new vector space integration method. This factorizes the numeric calculation into a part that depends only on the astrophysical velocity distribution; a second part, depending only on the detector form factor; and a scattering matrix defined on the basis functions, which depends on the details of the dark matter (DM) particle model (e.g. its mass). For common spin-independent DM-Standard Model interactions, this scattering matrix can be evaluated analytically in the wavelet-harmonic basis. This factorization is particularly helpful for the more complicated analyses that have become necessary in recent years, especially those involving anisotropic detector materials or more realistic models of the local DM velocity distribution. With the new method, analyses studying large numbers of detector orientations and DM particle models can be performed about 10 million times faster. This paper derives several analytic results for the spherical wavelets, including an extrapolation in the space of wavelet coefficients, and a generalization of the vector space method to a much broader class of linear functional integrals. Both results are highly relevant outside the field of DM direct detection.
[ { "created": "Mon, 2 Oct 2023 18:00:01 GMT", "version": "v1" } ]
2023-10-04
[ [ "Lillard", "Benjamin", "" ] ]
A new integration method drastically improves the efficiency of the dark matter direct detection calculation. In this work I introduce a complete, orthogonal basis of spherical wavelet-harmonic functions, designed for the new vector space integration method. This factorizes the numeric calculation into a part that depends only on the astrophysical velocity distribution; a second part, depending only on the detector form factor; and a scattering matrix defined on the basis functions, which depends on the details of the dark matter (DM) particle model (e.g. its mass). For common spin-independent DM-Standard Model interactions, this scattering matrix can be evaluated analytically in the wavelet-harmonic basis. This factorization is particularly helpful for the more complicated analyses that have become necessary in recent years, especially those involving anisotropic detector materials or more realistic models of the local DM velocity distribution. With the new method, analyses studying large numbers of detector orientations and DM particle models can be performed about 10 million times faster. This paper derives several analytic results for the spherical wavelets, including an extrapolation in the space of wavelet coefficients, and a generalization of the vector space method to a much broader class of linear functional integrals. Both results are highly relevant outside the field of DM direct detection.
hep-ph/0107041
Osman Yilmaz
A. Gokalp and O. Yilmaz (Middle East Technical University)
Coupling constants g$_{a_0\omega\gamma}$ and g$_{a_0\rho\gamma}$ as derived from QCD sum rules
9 pages, 4 figures, RevTex
Eur.Phys.J.C22:323-326,2001
10.1007/s100520100801
null
hep-ph
null
We consider the two point correlation function of scalar current in QCD sum rules approach to estimate the overlap amplitude of $a_0$ meson. We then employ QCD sum rules to calculate the coupling constants g$_{\omega a_0\gamma}$ and g$_{\rho a_0\gamma}$ by studying the three point ${a_0\omega\gamma}$- and ${a_0\rho\gamma}$-correlation functions.
[ { "created": "Thu, 5 Jul 2001 08:51:46 GMT", "version": "v1" } ]
2011-09-13
[ [ "Gokalp", "A.", "", "Middle East Technical University" ], [ "Yilmaz", "O.", "", "Middle East Technical University" ] ]
We consider the two point correlation function of scalar current in QCD sum rules approach to estimate the overlap amplitude of $a_0$ meson. We then employ QCD sum rules to calculate the coupling constants g$_{\omega a_0\gamma}$ and g$_{\rho a_0\gamma}$ by studying the three point ${a_0\omega\gamma}$- and ${a_0\rho\gamma}$-correlation functions.
2211.10230
Vanamali Shastry C
Vanamali Shastry
The hybrid nonet of $\pi_1(1600)$ and $\eta_1(1855)$: analysis and predictions for the kaonic members
Contribution to ICHEP-2022, Bologna, Italy
PoS(ICHEP2022)779
10.22323/1.414.0779
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
The hybrid mesons form a part of the exotic spectrum of the standard model. The recent observation of the isoscalar hybrid, called the $\eta_1(1855)$, provides an important step towards the completion of the $1^{-+}$ nonet. In the present work, we analyze the masses and two-body decays of the members of this nonet using a model hadronic Lagrangian. The isovector $\pi_1(1600)$ has been studied extensively - both experimentally and on lattice. We use the available experimental and lattice data to extract the coupling constants. Using these parameters, we analyze the possible decay channels for the hybrid kaons.
[ { "created": "Fri, 18 Nov 2022 13:35:57 GMT", "version": "v1" } ]
2022-12-13
[ [ "Shastry", "Vanamali", "" ] ]
The hybrid mesons form a part of the exotic spectrum of the standard model. The recent observation of the isoscalar hybrid, called the $\eta_1(1855)$, provides an important step towards the completion of the $1^{-+}$ nonet. In the present work, we analyze the masses and two-body decays of the members of this nonet using a model hadronic Lagrangian. The isovector $\pi_1(1600)$ has been studied extensively - both experimentally and on lattice. We use the available experimental and lattice data to extract the coupling constants. Using these parameters, we analyze the possible decay channels for the hybrid kaons.
hep-ph/9511253
Frank Cuypers
Frank Cuypers (PSI Villigen)
Selectron Searches in $e^-e^-$ Scattering
6 pages, talk presented at the Santa Cruz e-e- Workshop, UCSC, 4-5 September 1995
Int.J.Mod.Phys.A11:1585-1590,1996
10.1142/S0217751X96000778
MPI-PhT/95-108
hep-ph
null
We review the pair-production and decay of selectrons in $e^-e^-$ collisions and show how the standard model backgrounds can be virtually eliminated with polarized beams. The exceedingly simple analysis involved and the large sample of background-free supersymmetric events make this linear collider operating mode ideal for discovering selectrons and measuring the mass of the lightest neutralino.
[ { "created": "Tue, 7 Nov 1995 07:16:28 GMT", "version": "v1" } ]
2011-04-15
[ [ "Cuypers", "Frank", "", "PSI Villigen" ] ]
We review the pair-production and decay of selectrons in $e^-e^-$ collisions and show how the standard model backgrounds can be virtually eliminated with polarized beams. The exceedingly simple analysis involved and the large sample of background-free supersymmetric events make this linear collider operating mode ideal for discovering selectrons and measuring the mass of the lightest neutralino.
1611.08828
Andrey Grozin
Andrey Grozin
Lectures on Soft-Collinear Effective Theory
3 lectures given at the Helmholtz-DIAS International Summer School Quantum Field Theory at the Limits: from Strong Fields to Heavy Quarks, Dubna, July 18-30; v2: 4 refs added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Introductory lectures on SCET mainly following the first chapters of arXiv:1410.1892
[ { "created": "Sun, 27 Nov 2016 11:41:31 GMT", "version": "v1" }, { "created": "Sun, 4 Dec 2016 09:06:33 GMT", "version": "v2" } ]
2016-12-06
[ [ "Grozin", "Andrey", "" ] ]
Introductory lectures on SCET mainly following the first chapters of arXiv:1410.1892
2205.11522
Yuber F. Perez-Gonzalez
Nicol\'as Bernal, Yuber F. Perez-Gonzalez, Yong Xu
Superradiant Production of Heavy Dark Matter from Primordial Black Holes
20 pages, 5 figures. Added clarifying comments and references. Matches version accepted for publication in Phys. Rev D
null
10.1103/PhysRevD.106.015020
PI/UAN-2022-717FT, IPPP/22/33
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Rotating black holes (BHs) can efficiently transfer energy to the surrounding environment via superradiance. In particular, when the Compton length of a particle is comparable to the gravitational radius of a BH, the particle's occupation number can be exponentially amplified. In this work, we investigate the effect of the primordial-black-hole (PBH) superradiant instabilities on the generation of heavy bosonic dark matter (DM) with mass above $\sim$ 1 TeV. Additionally, we analyze its interplay with other purely gravitational and therefore unavoidable DM production mechanisms such as Hawking emission and the ultraviolet freeze-in. We find that superradiance can significantly increase the DM density produced by PBHs with respect to the case that only considers Hawking emission, and hence lower initial PBH densities are required.
[ { "created": "Mon, 23 May 2022 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 11 Jul 2022 09:36:27 GMT", "version": "v2" } ]
2022-08-31
[ [ "Bernal", "Nicolás", "" ], [ "Perez-Gonzalez", "Yuber F.", "" ], [ "Xu", "Yong", "" ] ]
Rotating black holes (BHs) can efficiently transfer energy to the surrounding environment via superradiance. In particular, when the Compton length of a particle is comparable to the gravitational radius of a BH, the particle's occupation number can be exponentially amplified. In this work, we investigate the effect of the primordial-black-hole (PBH) superradiant instabilities on the generation of heavy bosonic dark matter (DM) with mass above $\sim$ 1 TeV. Additionally, we analyze its interplay with other purely gravitational and therefore unavoidable DM production mechanisms such as Hawking emission and the ultraviolet freeze-in. We find that superradiance can significantly increase the DM density produced by PBHs with respect to the case that only considers Hawking emission, and hence lower initial PBH densities are required.
2001.10028
Claudius Krause
Christina Gao, Stefan Hoeche, Joshua Isaacson, Claudius Krause, Holger Schulz
Event Generation with Normalizing Flows
9 pages, 2 figures, 2 tables; v2: matches Journal version
Phys. Rev. D 101, 076002 (2020)
10.1103/PhysRevD.101.076002
FERMILAB-PUB-20-009-SCD-T, MCNET-20-03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel integrator based on normalizing flows which can be used to improve the unweighting efficiency of Monte-Carlo event generators for collider physics simulations. In contrast to machine learning approaches based on surrogate models, our method generates the correct result even if the underlying neural networks are not optimally trained. We exemplify the new strategy using the example of Drell-Yan type processes at the LHC, both at leading and partially at next-to-leading order QCD.
[ { "created": "Mon, 27 Jan 2020 19:22:55 GMT", "version": "v1" }, { "created": "Mon, 20 Apr 2020 18:02:52 GMT", "version": "v2" } ]
2020-04-22
[ [ "Gao", "Christina", "" ], [ "Hoeche", "Stefan", "" ], [ "Isaacson", "Joshua", "" ], [ "Krause", "Claudius", "" ], [ "Schulz", "Holger", "" ] ]
We present a novel integrator based on normalizing flows which can be used to improve the unweighting efficiency of Monte-Carlo event generators for collider physics simulations. In contrast to machine learning approaches based on surrogate models, our method generates the correct result even if the underlying neural networks are not optimally trained. We exemplify the new strategy using the example of Drell-Yan type processes at the LHC, both at leading and partially at next-to-leading order QCD.
1501.05900
Igor Anikin
I.V. Anikin, O.V. Teryaev
Gauge invariance and gluon poles for direct photon production
To appear in the proceedings of XXII International Baldin Seminar on High Energy Physics Problems, 15-20 September, 2014, JINR, Dubna, Russia
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the hadron tensor of the direct photon production. We study the effects which lead to the soft breaking of factorization by inspection of the corresponding QCD gauge invariance. We emphasize that the special role is played by the contour gauge for gluon fields. We demonstrate that the different prescriptions in the gluonic pole contributions are dictated by the presence of initial or final state interactions in diagrams. Moreover, the different prescriptions that correspond to the initial of final state interactions are needed to ensure the QCD gauge invariance.
[ { "created": "Fri, 23 Jan 2015 18:16:18 GMT", "version": "v1" } ]
2015-01-26
[ [ "Anikin", "I. V.", "" ], [ "Teryaev", "O. V.", "" ] ]
We discuss the hadron tensor of the direct photon production. We study the effects which lead to the soft breaking of factorization by inspection of the corresponding QCD gauge invariance. We emphasize that the special role is played by the contour gauge for gluon fields. We demonstrate that the different prescriptions in the gluonic pole contributions are dictated by the presence of initial or final state interactions in diagrams. Moreover, the different prescriptions that correspond to the initial of final state interactions are needed to ensure the QCD gauge invariance.
1603.08946
Stanislaw Mrowczynski
Stanislaw Mrowczynski, Bjoern Schenke and Michael Strickland
Color Instabilities in the Quark-Gluon Plasma
104 pages, review article published in Physics Reports 682, 1 (2017)
null
10.1016/j.physrep.2017.03.003
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When the quark-gluon plasma (QGP) - a system of deconfined quarks and gluons - is in a nonequilibrium state, it is usually unstable with respect to color collective modes. The instabilities, which are expected to strongly influence dynamics of the QGP produced in relativistic heavy-ion collisions, are extensively discussed under the assumption that the plasma is weakly coupled. We begin by presenting the theoretical approaches to study the QGP, which include: field theory methods based on the Keldysh-Schwinger formalism, classical and kinetic theories, and fluid techniques. The dispersion equations, which give the spectrum of plasma collective excitations, are analyzed in detail. Particular attention is paid to a momentum distribution of plasma constituents which is obtained by deforming an isotropic momentum distribution. Mechanisms of chromoelectric and chromomagnetic instabilities are explained in terms of elementary physics. The Nyquist analysis, which allows one to determine the number of solutions of a dispersion equation without explicitly solving it, and stability criteria are also discussed. We then review various numerical approaches - purely classical or quantum - to simulate the temporal evolution of an unstable quark-gluon plasma. The dynamical role of instabilities in the processes of plasma equilibration is analyzed.
[ { "created": "Tue, 29 Mar 2016 20:21:51 GMT", "version": "v1" }, { "created": "Wed, 31 May 2017 16:54:00 GMT", "version": "v2" } ]
2017-06-07
[ [ "Mrowczynski", "Stanislaw", "" ], [ "Schenke", "Bjoern", "" ], [ "Strickland", "Michael", "" ] ]
When the quark-gluon plasma (QGP) - a system of deconfined quarks and gluons - is in a nonequilibrium state, it is usually unstable with respect to color collective modes. The instabilities, which are expected to strongly influence dynamics of the QGP produced in relativistic heavy-ion collisions, are extensively discussed under the assumption that the plasma is weakly coupled. We begin by presenting the theoretical approaches to study the QGP, which include: field theory methods based on the Keldysh-Schwinger formalism, classical and kinetic theories, and fluid techniques. The dispersion equations, which give the spectrum of plasma collective excitations, are analyzed in detail. Particular attention is paid to a momentum distribution of plasma constituents which is obtained by deforming an isotropic momentum distribution. Mechanisms of chromoelectric and chromomagnetic instabilities are explained in terms of elementary physics. The Nyquist analysis, which allows one to determine the number of solutions of a dispersion equation without explicitly solving it, and stability criteria are also discussed. We then review various numerical approaches - purely classical or quantum - to simulate the temporal evolution of an unstable quark-gluon plasma. The dynamical role of instabilities in the processes of plasma equilibration is analyzed.
hep-ph/9502219
Ben Allanach
B. C. Allanach, S. F. King
Fermion Masses in a Supersymmetric SU(4)xSU(2)_LxSU(2)_R Model
Replaced version to appear in Nucl. Phys. B. Typos and other minor revisions. pages, uses epsf.sty, Latex. 13 uuencoded figures must be unpacked first (instructions at start of file.)
Nucl.Phys.B456:57-88,1995
10.1016/0550-3213(95)00466-4
SHEP 94-05
hep-ph
null
We calculate quark and lepton masses and quark mixing angles in the framework of a supersymmetric SU(4)$\otimes$SU(2)$_L\otimes$SU(2)$_R$ model where the gauge group is broken at 10$^{16}$ GeV. The model predicts third family top-bottom-tau Yukawa unification, as in minimal SO(10). The other smaller Yukawa couplings are assumed to arise from non-renormalisable operators suppressed by powers of some heavy scale. We perform a systematic operator analysis of the model in order to find the minimum set of operators which describe the low energy quark and lepton masses, and quark mixing angles consistent with low-energy phenomenology. A novel feature of the model is the possibility of asymmetric texture zeroes in the Yukawa matrices at the scale of the new physics. Successful predictions are obtained for $m_t$, $\tan \beta$, $m_s/m_\mu$, $m_d/m_e$ and $V_{ub}$ in terms of a CP violating phase $\phi$. For example, we predict $\tan \beta = 35-65$, $m_t = 130 - 190$ GeV, and $|V_{ub}|>0.0040$.
[ { "created": "Thu, 2 Feb 1995 15:35:43 GMT", "version": "v1" }, { "created": "Mon, 13 Feb 1995 14:12:26 GMT", "version": "v2" }, { "created": "Wed, 15 Feb 1995 09:48:36 GMT", "version": "v3" }, { "created": "Fri, 1 Sep 1995 14:19:46 GMT", "version": "v4" } ]
2010-11-01
[ [ "Allanach", "B. C.", "" ], [ "King", "S. F.", "" ] ]
We calculate quark and lepton masses and quark mixing angles in the framework of a supersymmetric SU(4)$\otimes$SU(2)$_L\otimes$SU(2)$_R$ model where the gauge group is broken at 10$^{16}$ GeV. The model predicts third family top-bottom-tau Yukawa unification, as in minimal SO(10). The other smaller Yukawa couplings are assumed to arise from non-renormalisable operators suppressed by powers of some heavy scale. We perform a systematic operator analysis of the model in order to find the minimum set of operators which describe the low energy quark and lepton masses, and quark mixing angles consistent with low-energy phenomenology. A novel feature of the model is the possibility of asymmetric texture zeroes in the Yukawa matrices at the scale of the new physics. Successful predictions are obtained for $m_t$, $\tan \beta$, $m_s/m_\mu$, $m_d/m_e$ and $V_{ub}$ in terms of a CP violating phase $\phi$. For example, we predict $\tan \beta = 35-65$, $m_t = 130 - 190$ GeV, and $|V_{ub}|>0.0040$.
1705.06178
Sofia Leit\~ao
Sofia Leit\~ao, Yang Li, Pieter Maris, M. T. Pe\~na, Alfred Stadler, James P. Vary and Elmar P. Biernat
Comparison of two Minkowski-space approaches to heavy quarkonia
16 pages
null
10.1140/epjc/s10052-017-5248-0
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we compare mass spectra and decay constants obtained from two recent, independent, and fully relativistic approaches to the quarkonium bound-state problem: the Hamiltonian basis light-front quantization (BLFQ) approach, where light-front wave functions are naturally formulated; and, the covariant spectator theory (CST), based on a reorganization of the Bethe-Salpeter equation. Even though conceptually different, both solutions are obtained in Minkowski space. Comparisons of decay constants for more than ten states of charmonium and bottomonium show favorable agreement between the two approaches as well as with experiment where available. We also apply the Brodsky-Huang-Lepage prescription to convert the CST amplitudes into functions of light-front variables. This provides an ideal opportunity to investigate the similarities and differences at the level of the wave functions. Several qualitative features are observed in remarkable agreement between the two approaches even for the rarely addressed excited states. Leading twist distribution amplitudes as well as parton distribution functions of heavy quarkonia are also analyzed.
[ { "created": "Wed, 17 May 2017 14:33:38 GMT", "version": "v1" } ]
2017-11-22
[ [ "Leitão", "Sofia", "" ], [ "Li", "Yang", "" ], [ "Maris", "Pieter", "" ], [ "Peña", "M. T.", "" ], [ "Stadler", "Alfred", "" ], [ "Vary", "James P.", "" ], [ "Biernat", "Elmar P.", "" ] ]
In this work we compare mass spectra and decay constants obtained from two recent, independent, and fully relativistic approaches to the quarkonium bound-state problem: the Hamiltonian basis light-front quantization (BLFQ) approach, where light-front wave functions are naturally formulated; and, the covariant spectator theory (CST), based on a reorganization of the Bethe-Salpeter equation. Even though conceptually different, both solutions are obtained in Minkowski space. Comparisons of decay constants for more than ten states of charmonium and bottomonium show favorable agreement between the two approaches as well as with experiment where available. We also apply the Brodsky-Huang-Lepage prescription to convert the CST amplitudes into functions of light-front variables. This provides an ideal opportunity to investigate the similarities and differences at the level of the wave functions. Several qualitative features are observed in remarkable agreement between the two approaches even for the rarely addressed excited states. Leading twist distribution amplitudes as well as parton distribution functions of heavy quarkonia are also analyzed.
hep-ph/0002080
Chris Quigg
Chris Quigg
Perspectives in High-Energy Physics
27 pages, 12 figures, uses aipproc (included) and boxedeps. Review lecture at the ICFA Instrumentation School, Istanbul, 30 June 1999
null
10.1063/1.1361761
FERMILAB-Conf-00/041-T
hep-ph
null
I sketch some pressing questions in several active areas of particle physics and outline the challenges they present for the design and operation of detectors.
[ { "created": "Mon, 7 Feb 2000 23:18:44 GMT", "version": "v1" } ]
2009-10-31
[ [ "Quigg", "Chris", "" ] ]
I sketch some pressing questions in several active areas of particle physics and outline the challenges they present for the design and operation of detectors.
hep-ph/0304272
Carlo Oleari
A. Brandenburg, P. Nason and C. Oleari
On a possible measurement of alpha_s from B-Bbar correlations in Z^0 decay
18 pages, 3 figures
Nucl.Phys.B667:394-410,2003
10.1016/S0550-3213(03)00530-3
null
hep-ph
null
Motivated by recent preliminary results from the SLD Collaboration on the measurement of angle-dependent B-Bbar energy correlations in Z^0 -> b bbar events, we propose a class of observables that can be computed as a power expansion in the strong coupling constant alpha_s, of order alpha_s at the Born level and that can be used for a precision measurement of alpha_s(M_Z). We compute their next-to-leading order O(alpha_s^2) corrections in the strong coupling constant, including exactly quark-mass effects. We show that, in the theoretical evaluation of these quantities, large logarithms of the ratio of the mass of the final quark over the centre-of-mass energy cancel out. Thus, these variables have a well-behaved perturbative expansion in alpha_s(M_Z). We study the theoretical uncertainties due to the renormalization-scale dependence and the quark-mass scheme and we address the question of which mass scheme is more appropriate for these variables.
[ { "created": "Tue, 29 Apr 2003 15:32:35 GMT", "version": "v1" } ]
2008-11-26
[ [ "Brandenburg", "A.", "" ], [ "Nason", "P.", "" ], [ "Oleari", "C.", "" ] ]
Motivated by recent preliminary results from the SLD Collaboration on the measurement of angle-dependent B-Bbar energy correlations in Z^0 -> b bbar events, we propose a class of observables that can be computed as a power expansion in the strong coupling constant alpha_s, of order alpha_s at the Born level and that can be used for a precision measurement of alpha_s(M_Z). We compute their next-to-leading order O(alpha_s^2) corrections in the strong coupling constant, including exactly quark-mass effects. We show that, in the theoretical evaluation of these quantities, large logarithms of the ratio of the mass of the final quark over the centre-of-mass energy cancel out. Thus, these variables have a well-behaved perturbative expansion in alpha_s(M_Z). We study the theoretical uncertainties due to the renormalization-scale dependence and the quark-mass scheme and we address the question of which mass scheme is more appropriate for these variables.
hep-ph/0204032
Reinhard Stock
Reinhard Stock
Bulk Hadron Production at AGS and SPS
null
null
null
null
hep-ph
null
With new data available from the SPS, at 40 and 80 GeV/A, I review the systematics of bulk hadron multiplicities, with prime focus on strangeness production. The classical concept of strangeness enhancement in central AA collisions is reviewed, in view of the statistical hadronization model which suggests to understand strangeness enhancement to arise chiefly in the transition from the canonical to the grand canonical version of that model. I. e. enhancement results from the fading away of canonical suppression. The model also captures the striking strangeness maximum observed in the vicinity of $\sqrt{s} \approx $ 8 GeV. A puzzle remains in the understanding of apparent grand canonical order at the lower SPS, and at AGS energies.
[ { "created": "Wed, 3 Apr 2002 09:19:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Stock", "Reinhard", "" ] ]
With new data available from the SPS, at 40 and 80 GeV/A, I review the systematics of bulk hadron multiplicities, with prime focus on strangeness production. The classical concept of strangeness enhancement in central AA collisions is reviewed, in view of the statistical hadronization model which suggests to understand strangeness enhancement to arise chiefly in the transition from the canonical to the grand canonical version of that model. I. e. enhancement results from the fading away of canonical suppression. The model also captures the striking strangeness maximum observed in the vicinity of $\sqrt{s} \approx $ 8 GeV. A puzzle remains in the understanding of apparent grand canonical order at the lower SPS, and at AGS energies.
hep-ph/0011392
Michael Gronau
Michael Gronau
CKM Phases from CP Asymmetries
minor corrections, several references added and updated
Nucl.Instrum.Meth.A462:1-10,2001
10.1016/S0168-9002(01)00019-5
null
hep-ph hep-ex
null
Measuring phases in the Cabibbo-Kobayashi-Maskawa matrix through CP asymmetries in B decays is a major goal of current and future experiments. Methods based on charge-conjugation and isospin symmetries involve very little theoretical uncertainties, while schemes based on flavor SU(3) involve uncertainties due to SU(3) breaking. Resolving these uncertainties requires further studies involving a dialogue between theory and experiments.
[ { "created": "Thu, 30 Nov 2000 16:05:29 GMT", "version": "v1" }, { "created": "Thu, 7 Dec 2000 16:30:23 GMT", "version": "v2" } ]
2008-11-26
[ [ "Gronau", "Michael", "" ] ]
Measuring phases in the Cabibbo-Kobayashi-Maskawa matrix through CP asymmetries in B decays is a major goal of current and future experiments. Methods based on charge-conjugation and isospin symmetries involve very little theoretical uncertainties, while schemes based on flavor SU(3) involve uncertainties due to SU(3) breaking. Resolving these uncertainties requires further studies involving a dialogue between theory and experiments.
1910.12685
Sebastian Jaskiewicz
Martin Beneke, Mathias Garny, Sebastian Jaskiewicz, Robert Szafron, Leonardo Vernazza, Jian Wang
Leading-logarithmic threshold resummation of Higgs production in gluon fusion at next-to-leading power
19 pages, 2 figures, and 2 tables
null
10.1007/JHEP01(2020)094
TUM-HEP-1235/19, NIKHEF/2019-048, CERN-TH-2019-176
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We sum the leading logarithms $\alpha_s^n \ln^{2 n-1}(1-z)$, n=1,2,... near the kinematic threshold $z=m_H^2/\hat{s}\to 1$ at next-to-leading power in the expansion in (1-z) for Higgs production in gluon fusion. We highlight the new contributions compared to Drell-Yan production in quark-antiquark annihilation and show that the final result can be obtained to all orders by the substitution of the colour factor $C_F\to C_A$, confirming previous fixed-order results and conjectures. We also provide a numerical analysis of the next-to-leading power leading logarithms, which indicates that they are numerically relevant.
[ { "created": "Mon, 28 Oct 2019 13:59:47 GMT", "version": "v1" } ]
2020-02-19
[ [ "Beneke", "Martin", "" ], [ "Garny", "Mathias", "" ], [ "Jaskiewicz", "Sebastian", "" ], [ "Szafron", "Robert", "" ], [ "Vernazza", "Leonardo", "" ], [ "Wang", "Jian", "" ] ]
We sum the leading logarithms $\alpha_s^n \ln^{2 n-1}(1-z)$, n=1,2,... near the kinematic threshold $z=m_H^2/\hat{s}\to 1$ at next-to-leading power in the expansion in (1-z) for Higgs production in gluon fusion. We highlight the new contributions compared to Drell-Yan production in quark-antiquark annihilation and show that the final result can be obtained to all orders by the substitution of the colour factor $C_F\to C_A$, confirming previous fixed-order results and conjectures. We also provide a numerical analysis of the next-to-leading power leading logarithms, which indicates that they are numerically relevant.
hep-ph/0212269
Antonio Lopez Maroto
J. Alcaraz, J.A.R. Cembranos, A. Dobado, A.L. Maroto
Limits on the brane fluctuations mass and on the brane tension scale from electron-positron colliders
LaTeX, 38 pages, 7 figures. Minor changes, matches published version
Phys.Rev.D67:075010,2003
10.1103/PhysRevD.67.075010
null
hep-ph hep-th
null
In the context of the brane-world scenarios with compactified large extra dimensions, we study the production of the possible massive brane oscillations (branons) in electron-positron colliders. We compute their contribution to the electroweak gauge bosons decay width and to the single-photon and single-Z processes. With LEP-I results and assuming non observation at LEP-II, we present exclusion plots for the brane tension $\tau = f^4$ and the branon mass $M$. Prospects for the next generation of electron-positron colliders are also considered.
[ { "created": "Wed, 18 Dec 2002 19:14:05 GMT", "version": "v1" }, { "created": "Tue, 6 May 2003 17:33:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Alcaraz", "J.", "" ], [ "Cembranos", "J. A. R.", "" ], [ "Dobado", "A.", "" ], [ "Maroto", "A. L.", "" ] ]
In the context of the brane-world scenarios with compactified large extra dimensions, we study the production of the possible massive brane oscillations (branons) in electron-positron colliders. We compute their contribution to the electroweak gauge bosons decay width and to the single-photon and single-Z processes. With LEP-I results and assuming non observation at LEP-II, we present exclusion plots for the brane tension $\tau = f^4$ and the branon mass $M$. Prospects for the next generation of electron-positron colliders are also considered.
0912.2661
Shun Zhou
He Zhang and Shun Zhou
The Minimal Seesaw Model at the TeV Scale
6 pages, 2 figures
Phys.Lett.B685:297-301,2010
10.1016/j.physletb.2010.02.015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We point out that the minimal seesaw model can provide a natural framework to accommodate tiny neutrino masses, while its experimental testability and notable predictiveness are still maintained. This possibility is based on the observation that two heavy right-handed Majorana neutrinos in the minimal seesaw model may naturally emerge as a pseudo-Dirac fermion. In a specific scenario, we show that the tri-bimaximal neutrino mixing can be produced, and only the inverted neutrino mass hierarchy is allowed. The low-energy phenomena, including non-unitarity effects in neutrino oscillations, neutrinoless double-beta decays and rare lepton-flavor-violating decays of charged leptons l_alpha to l_beta + gamma, have been explored. The collider signatures of the heavy singlet neutrino are also briefly discussed.
[ { "created": "Mon, 14 Dec 2009 15:16:21 GMT", "version": "v1" } ]
2010-05-12
[ [ "Zhang", "He", "" ], [ "Zhou", "Shun", "" ] ]
We point out that the minimal seesaw model can provide a natural framework to accommodate tiny neutrino masses, while its experimental testability and notable predictiveness are still maintained. This possibility is based on the observation that two heavy right-handed Majorana neutrinos in the minimal seesaw model may naturally emerge as a pseudo-Dirac fermion. In a specific scenario, we show that the tri-bimaximal neutrino mixing can be produced, and only the inverted neutrino mass hierarchy is allowed. The low-energy phenomena, including non-unitarity effects in neutrino oscillations, neutrinoless double-beta decays and rare lepton-flavor-violating decays of charged leptons l_alpha to l_beta + gamma, have been explored. The collider signatures of the heavy singlet neutrino are also briefly discussed.
hep-ph/9203202
Cliff Burgess
C.P. Burgess, J. Cline and Markus Luty
A Natural Framework for Solar and 17 keV Neutrinos
23 pages
Phys.Rev. D46 (1992) 364-373
10.1103/PhysRevD.46.364
null
hep-ph
null
Motivated by recent experimental claims for the existence of a 17 keV neutrino and by the solar neutrino problem, we construct a class of models which contain in their low-energy spectrum a single light sterile neutrino and one or more Nambu-Goldstone bosons. In these models the required pattern of breaking of lepton-number symmetry takes place near the electroweak scale and all mass heirarchies are technically natural. The models are compatible with all cosmological and astrophysical constraints, and can solve the solar neutrino problem via either the MSW effect or vacuum oscillations. The deficit in atmospheric muon neutrinos seen in the Kamiokande and IMB detectors can also be explained in these models.
[ { "created": "Sun, 8 Mar 1992 23:36:56 GMT", "version": "v1" } ]
2009-10-22
[ [ "Burgess", "C. P.", "" ], [ "Cline", "J.", "" ], [ "Luty", "Markus", "" ] ]
Motivated by recent experimental claims for the existence of a 17 keV neutrino and by the solar neutrino problem, we construct a class of models which contain in their low-energy spectrum a single light sterile neutrino and one or more Nambu-Goldstone bosons. In these models the required pattern of breaking of lepton-number symmetry takes place near the electroweak scale and all mass heirarchies are technically natural. The models are compatible with all cosmological and astrophysical constraints, and can solve the solar neutrino problem via either the MSW effect or vacuum oscillations. The deficit in atmospheric muon neutrinos seen in the Kamiokande and IMB detectors can also be explained in these models.
hep-ph/9912258
Dmity Ostovsky
Dmitry Ostrovsky (P.N. Lebedev Physical Institute, Moscow, Russia)
NLO correction to one-particle inclusive production at high energies
21 pages, 4 eps figures
Phys.Rev.D62:054028,2000
10.1103/PhysRevD.62.054028
FIAN/TD-25/99
hep-ph
null
Next-to-leading order correction to the one-particle inclusive cross section in the framework of high energy factorization is calculated. Numerical results for midrapidity region are compared with predictions of conventional calculations based on collinear factorization.
[ { "created": "Tue, 7 Dec 1999 10:15:14 GMT", "version": "v1" } ]
2014-11-17
[ [ "Ostrovsky", "Dmitry", "", "P.N. Lebedev Physical Institute, Moscow, Russia" ] ]
Next-to-leading order correction to the one-particle inclusive cross section in the framework of high energy factorization is calculated. Numerical results for midrapidity region are compared with predictions of conventional calculations based on collinear factorization.
1606.06893
Francesca Aceti
F. Aceti, L. R. Dai and E. Oset
The "$a_1(1420)$" peak as the $\pi f_0(980)$ decay mode of the $a_1(1260)$
null
Phys. Rev. D 94, 096015 (2016)
10.1103/PhysRevD.94.096015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the decay mode of the $a_1(1260)$ into a $\pi^+$ in p-wave and the $f_0(980)$ that decays into $\pi^+ \pi^-$ in s-wave. The mechanisms proceeds via a triangular mechanism where the $a_1(1260)$ decays into $K^* \bar K$, the $K^*$ decays to an external $\pi^+$ and an internal $K$ that fuses with the $\bar K$ to produce the $f_0(980)$ resonance. The mechanism develops a singularity at a mass of the $a_1(1260)$ around 1420 MeV, producing a peak in the cross section of the $\pi p$ reaction, used to generate the mesonic final state, which provides a natural explanation of all the features observed in the COMPASS experiment, where a peak observed at this energy is tentatively associated to a new resonance called $a_1(1420)$. On the other hand, the triangular singularity studied here gives rise to a remarkable feature, where a peak is seen for a certain decay channel of a resonance at an energy about 200 MeV higher than its nominal mass.
[ { "created": "Wed, 22 Jun 2016 10:50:47 GMT", "version": "v1" }, { "created": "Wed, 29 Jun 2016 10:32:50 GMT", "version": "v2" } ]
2016-12-07
[ [ "Aceti", "F.", "" ], [ "Dai", "L. R.", "" ], [ "Oset", "E.", "" ] ]
We study the decay mode of the $a_1(1260)$ into a $\pi^+$ in p-wave and the $f_0(980)$ that decays into $\pi^+ \pi^-$ in s-wave. The mechanisms proceeds via a triangular mechanism where the $a_1(1260)$ decays into $K^* \bar K$, the $K^*$ decays to an external $\pi^+$ and an internal $K$ that fuses with the $\bar K$ to produce the $f_0(980)$ resonance. The mechanism develops a singularity at a mass of the $a_1(1260)$ around 1420 MeV, producing a peak in the cross section of the $\pi p$ reaction, used to generate the mesonic final state, which provides a natural explanation of all the features observed in the COMPASS experiment, where a peak observed at this energy is tentatively associated to a new resonance called $a_1(1420)$. On the other hand, the triangular singularity studied here gives rise to a remarkable feature, where a peak is seen for a certain decay channel of a resonance at an energy about 200 MeV higher than its nominal mass.
0803.4119
Alexandre Deur
A. Deur, V. Burkert, J.P. Chen and W. Korsch
Determination of the effective strong coupling constant alpha_{s,g_1}(Q^2) from CLAS spin structure function data
Updated to the version published in PLB (minor modifications)
Phys.Lett.B665:349-351,2008
10.1016/j.physletb.2008.06.049
JLAB-PHY-08-808, DOE/OR/23177-0337
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new extraction of the effective strong coupling constant \alpha_{s,g_1}(Q^2). The result agrees with a previous determination and extends the measurement of the low and high Q^2 behavior of \alpha_{s,g_1}(Q^2) that was previously deduced from sum rules. In particular, it experimentally verifies the lack of Q^2-dependence of \alpha_{s,g_1}(Q^2) in the low Q^2 limit. This fact is necessary for application of the AdS/CFT correspondence to QCD calculations. We provide a parameterization of \alpha_{s,g_1}(Q^2) thatcan equivalently be used to parameterize the Q^2-dependence of the generalized Gerasimov-Drell-Hearn and Bjorken sums.
[ { "created": "Fri, 28 Mar 2008 14:01:39 GMT", "version": "v1" }, { "created": "Mon, 21 Jul 2008 14:14:14 GMT", "version": "v2" } ]
2008-11-26
[ [ "Deur", "A.", "" ], [ "Burkert", "V.", "" ], [ "Chen", "J. P.", "" ], [ "Korsch", "W.", "" ] ]
We present a new extraction of the effective strong coupling constant \alpha_{s,g_1}(Q^2). The result agrees with a previous determination and extends the measurement of the low and high Q^2 behavior of \alpha_{s,g_1}(Q^2) that was previously deduced from sum rules. In particular, it experimentally verifies the lack of Q^2-dependence of \alpha_{s,g_1}(Q^2) in the low Q^2 limit. This fact is necessary for application of the AdS/CFT correspondence to QCD calculations. We provide a parameterization of \alpha_{s,g_1}(Q^2) thatcan equivalently be used to parameterize the Q^2-dependence of the generalized Gerasimov-Drell-Hearn and Bjorken sums.
1308.5553
Yu. A. Simonov
Yu. A. Simonov (Institute of Theoretical and Experimental Physics, Moscow, Russia)
Magnetic focusing in atomic, nuclear and hadronic processes
18 pages
Phys. Rev. D 88, 093001 (2013)
10.1103/PhysRevD.88.093001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Processes with oppositely charged spinor particles in initial and/or final states in homogeneous magnetic field B are subject to focusing effects in their relative motion, which yield the amplifying factors in probabilities growing as $eB$. In addition the increasing energy of some Landau levels influences the phase space. As a result some processes in the proper spin states can be enlarged as $\sim \frac{eB}{\kappa^2}$, where $\kappa^2$ is the characteristic 2d phase space factor available without magnetic field. Several examples, including neutron $\beta$ decay, positronium decay and $e^+e^-$ pair production, are quantitatively considered.
[ { "created": "Mon, 26 Aug 2013 12:22:34 GMT", "version": "v1" } ]
2015-05-14
[ [ "Simonov", "Yu. A.", "", "Institute of Theoretical and Experimental Physics,\n Moscow, Russia" ] ]
Processes with oppositely charged spinor particles in initial and/or final states in homogeneous magnetic field B are subject to focusing effects in their relative motion, which yield the amplifying factors in probabilities growing as $eB$. In addition the increasing energy of some Landau levels influences the phase space. As a result some processes in the proper spin states can be enlarged as $\sim \frac{eB}{\kappa^2}$, where $\kappa^2$ is the characteristic 2d phase space factor available without magnetic field. Several examples, including neutron $\beta$ decay, positronium decay and $e^+e^-$ pair production, are quantitatively considered.
hep-ph/0506079
Philip Schuster
Philip C. Schuster, Natalia Toro
Is Dark Matter Heavy Because of Electroweak Symmetry Breaking? Revisiting Heavy Neutrinos
36 pages, 10 figures and 1 table, references fixed
null
null
null
hep-ph astro-ph
null
A simple and well-motivated explanation for the origin of dark matter is that it consists of thermal relic particles that get their mass entirely through electroweak symmetry breaking. The simplest models implementing this possibility predict a dark matter candidate that consists of a mixture of two Dirac neutrinos with opposite isospin, and so has suppressed coupling to the Z. These models predict dark matter masses of m_{DM}~45 GeV or m_{DM}~90-95 GeV and WIMP-neutron spin-independent cross sections \sigma_{WIMP-n}~10^{-6}-10^{-8} pb. Current direct dark matter searches are probing a portion of the parameter space of these models while future experiments sensitive to \sigma_{WIMP-n}~10^{-8} pb will probe the remainder. An enhancement of the galactic halo gamma ray and positron flux coming from annihilations of these particles is also expected across the ~1-100 GeV range. The framework further suggests an environmental explanation of the hierarchy between the weak and Planck scales and of the small value of the cosmological constant relative to the weak scale.
[ { "created": "Wed, 8 Jun 2005 09:17:48 GMT", "version": "v1" }, { "created": "Thu, 9 Jun 2005 16:40:17 GMT", "version": "v2" } ]
2007-05-23
[ [ "Schuster", "Philip C.", "" ], [ "Toro", "Natalia", "" ] ]
A simple and well-motivated explanation for the origin of dark matter is that it consists of thermal relic particles that get their mass entirely through electroweak symmetry breaking. The simplest models implementing this possibility predict a dark matter candidate that consists of a mixture of two Dirac neutrinos with opposite isospin, and so has suppressed coupling to the Z. These models predict dark matter masses of m_{DM}~45 GeV or m_{DM}~90-95 GeV and WIMP-neutron spin-independent cross sections \sigma_{WIMP-n}~10^{-6}-10^{-8} pb. Current direct dark matter searches are probing a portion of the parameter space of these models while future experiments sensitive to \sigma_{WIMP-n}~10^{-8} pb will probe the remainder. An enhancement of the galactic halo gamma ray and positron flux coming from annihilations of these particles is also expected across the ~1-100 GeV range. The framework further suggests an environmental explanation of the hierarchy between the weak and Planck scales and of the small value of the cosmological constant relative to the weak scale.
2007.03696
Paul Frederik Depta
Torsten Bringmann, Paul Frederik Depta, Marco Hufnagel, and Kai Schmidt-Hoberg
Precise dark matter relic abundance in decoupled sectors
9 pages, 4 figures; v2: discussion extended, matches published version
Phys. Lett. B 817, 136341 (2021)
10.1016/j.physletb.2021.136341
DESY 20-113
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter (DM) as a thermal relic of the primordial plasma is increasingly pressured by direct and indirect searches, while the same production mechanism in a decoupled sector is much less constrained. We extend the standard treatment of the freeze-out process to such scenarios and perform precision calculations of the annihilation cross-section required to match the observed DM abundance. We demonstrate that the difference to the canonical value of this 'thermal cross-section' is generally sizeable, and can reach orders of magnitude. Our results directly impact the interpretation of DM searches in hidden sector scenarios.
[ { "created": "Tue, 7 Jul 2020 18:00:02 GMT", "version": "v1" }, { "created": "Tue, 18 May 2021 13:17:49 GMT", "version": "v2" } ]
2021-05-19
[ [ "Bringmann", "Torsten", "" ], [ "Depta", "Paul Frederik", "" ], [ "Hufnagel", "Marco", "" ], [ "Schmidt-Hoberg", "Kai", "" ] ]
Dark matter (DM) as a thermal relic of the primordial plasma is increasingly pressured by direct and indirect searches, while the same production mechanism in a decoupled sector is much less constrained. We extend the standard treatment of the freeze-out process to such scenarios and perform precision calculations of the annihilation cross-section required to match the observed DM abundance. We demonstrate that the difference to the canonical value of this 'thermal cross-section' is generally sizeable, and can reach orders of magnitude. Our results directly impact the interpretation of DM searches in hidden sector scenarios.
1305.6277
Tomasz Jelinski
Tomasz Jelinski
On messengers couplings in extended GMSB models
20 pages, 3 figures, 16 tables
null
10.1007/JHEP09(2013)107
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss, for the first time, the role of the superpotential couplings of three messenger fields in a GMSB-type unification model in which messenger sector consists of both 5+5bar and 10+10bar of SU(5). It turns out that these interactions are relevant when coexist with appropriate messenger-MSSM couplings. Then they induce extra contributions to 2-loop soft masses. In the present model, we derive all such soft terms and discuss constraints which have to be satisfied to avoid rapid proton decay and mu/B_mu problem. As an example, it is shown how superpotential couplings of three messengers influence mass spectra when the model is restricted by additional global U(1)_q symmetry. We find that masses of the lightest sleptons are the most sensitive to those new interactions, what in some cases results in the NLSP/NNLSP pattern in which stau or selectron is lighter than the lightest neutralino.
[ { "created": "Mon, 27 May 2013 17:21:52 GMT", "version": "v1" } ]
2015-06-16
[ [ "Jelinski", "Tomasz", "" ] ]
We discuss, for the first time, the role of the superpotential couplings of three messenger fields in a GMSB-type unification model in which messenger sector consists of both 5+5bar and 10+10bar of SU(5). It turns out that these interactions are relevant when coexist with appropriate messenger-MSSM couplings. Then they induce extra contributions to 2-loop soft masses. In the present model, we derive all such soft terms and discuss constraints which have to be satisfied to avoid rapid proton decay and mu/B_mu problem. As an example, it is shown how superpotential couplings of three messengers influence mass spectra when the model is restricted by additional global U(1)_q symmetry. We find that masses of the lightest sleptons are the most sensitive to those new interactions, what in some cases results in the NLSP/NNLSP pattern in which stau or selectron is lighter than the lightest neutralino.
2310.03425
Rui-Lin Zhu
Yiqi Geng, Mingqi Cao, Ruilin Zhu
Distinguishing Low-lying Vector Beauty-charm Meson via Polarization Analysis
6 pages, 4 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
To distinguish the low-lying vector beauty-charm meson, we systematically study the $B_c^*\to B_c+\gamma$, $B_c^*\to \ell+{\nu}_{\ell}$ and $B_c^{(*)}\to J/\psi+nh$ processes within effective theory by the helicity decomposition method. The significant difference of polarization asymmetry in $B_c^{(*)}\to J/\psi+nh$ indicates a general law in vector-to-vector and pseudoscalar-to-vector transition processes, which can be tested in current and future LHC experiments. In the end, we discuss the experiment search and discovery potential for the low-lying vector beauty-charm meson.
[ { "created": "Thu, 5 Oct 2023 10:04:15 GMT", "version": "v1" } ]
2023-10-06
[ [ "Geng", "Yiqi", "" ], [ "Cao", "Mingqi", "" ], [ "Zhu", "Ruilin", "" ] ]
To distinguish the low-lying vector beauty-charm meson, we systematically study the $B_c^*\to B_c+\gamma$, $B_c^*\to \ell+{\nu}_{\ell}$ and $B_c^{(*)}\to J/\psi+nh$ processes within effective theory by the helicity decomposition method. The significant difference of polarization asymmetry in $B_c^{(*)}\to J/\psi+nh$ indicates a general law in vector-to-vector and pseudoscalar-to-vector transition processes, which can be tested in current and future LHC experiments. In the end, we discuss the experiment search and discovery potential for the low-lying vector beauty-charm meson.
1709.08562
Dan Hooper
Ti-Lin Chou, Dimitrios Tanoglidis, Dan Hooper
Resolving Dark Matter Subhalos With Future Sub-GeV Gamma-Ray Telescopes
12 pages, 5 figures
null
null
FERMILAB-PUB-17-390-A
hep-ph astro-ph.CO astro-ph.GA astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Annihilating dark matter particles in nearby subhalos could generate potentially observable fluxes of gamma rays, unaccompanied by emission at other wavelengths. Furthermore, this gamma-ray emission is expected to be spatially extended, providing us with a powerful way to discriminate dark matter subhalos from other astrophysical gamma-ray sources. Fermi has detected two dark matter subhalo candidates which exhibit a statistically significant degree of spatial extension (3FGL J2212.5+0703 and 3FGL J1924.8-1034). It has been argued that the most likely non-dark matter interpretation of these observations is that they are each in fact multiple nearby point sources, too close to one another on the sky to be individually resolved. In this study, we consider the ability of next generation gamma-ray telescopes to spatially resolve the gamma-ray emission from subhalo candidates, focusing on the proposed e-ASTROGAM mission. We find that such an instrument could significantly clarify the nature of Fermi's dark matter subhalo candidates, and provide an unprecedented level of sensitivity to the presence of annihilating dark matter in nearby subhalos.
[ { "created": "Mon, 25 Sep 2017 15:53:08 GMT", "version": "v1" } ]
2017-09-26
[ [ "Chou", "Ti-Lin", "" ], [ "Tanoglidis", "Dimitrios", "" ], [ "Hooper", "Dan", "" ] ]
Annihilating dark matter particles in nearby subhalos could generate potentially observable fluxes of gamma rays, unaccompanied by emission at other wavelengths. Furthermore, this gamma-ray emission is expected to be spatially extended, providing us with a powerful way to discriminate dark matter subhalos from other astrophysical gamma-ray sources. Fermi has detected two dark matter subhalo candidates which exhibit a statistically significant degree of spatial extension (3FGL J2212.5+0703 and 3FGL J1924.8-1034). It has been argued that the most likely non-dark matter interpretation of these observations is that they are each in fact multiple nearby point sources, too close to one another on the sky to be individually resolved. In this study, we consider the ability of next generation gamma-ray telescopes to spatially resolve the gamma-ray emission from subhalo candidates, focusing on the proposed e-ASTROGAM mission. We find that such an instrument could significantly clarify the nature of Fermi's dark matter subhalo candidates, and provide an unprecedented level of sensitivity to the presence of annihilating dark matter in nearby subhalos.
hep-ph/0103009
Dominik Stockinger
W. Hollik, D. St\"ockinger
Regularization and supersymmetry-restoring counterterms in supersymmetric QCD
15 pages, 9 figures, uses svjour.cls and svepj.clo, references added, accepted for publication in Eur.Phys.J.C
Eur.Phys.J.C20:105-119,2001
10.1007/s100520100651
KA-TP-08-2001
hep-ph
null
We calculate symmetry-restoring counterterms in supersymmetric QCD at the one-loop level. First we determine loop corrections to the supersymmetry and gauge transformations and find counterterms in such a way that the symmetry algebra holds at the one-loop level. Then these results are used to derive the symmetry-restoring counterterms to all trilinear interactions. In order to obtain unique results it is crucial to use the Slavnov-Taylor identity, which does not only contain supersymmetric and gauge Ward identities but also describes the symmetry algebra. In dimensional regularization this procedure yields unique non-zero values for the counterterms. In contrast, in dimensional reduction we find that no non-symmetric counterterms are needed, neither for the symmetry transformations nor for the physical interactions. For the considered cases this result constitutes a definite test of the supersymmetry and gauge invariance of the scheme.
[ { "created": "Thu, 1 Mar 2001 14:56:15 GMT", "version": "v1" }, { "created": "Tue, 20 Mar 2001 14:27:45 GMT", "version": "v2" }, { "created": "Wed, 21 Mar 2001 19:15:52 GMT", "version": "v3" } ]
2009-09-25
[ [ "Hollik", "W.", "" ], [ "Stöckinger", "D.", "" ] ]
We calculate symmetry-restoring counterterms in supersymmetric QCD at the one-loop level. First we determine loop corrections to the supersymmetry and gauge transformations and find counterterms in such a way that the symmetry algebra holds at the one-loop level. Then these results are used to derive the symmetry-restoring counterterms to all trilinear interactions. In order to obtain unique results it is crucial to use the Slavnov-Taylor identity, which does not only contain supersymmetric and gauge Ward identities but also describes the symmetry algebra. In dimensional regularization this procedure yields unique non-zero values for the counterterms. In contrast, in dimensional reduction we find that no non-symmetric counterterms are needed, neither for the symmetry transformations nor for the physical interactions. For the considered cases this result constitutes a definite test of the supersymmetry and gauge invariance of the scheme.
hep-ph/0212273
Shouhua Zhu
Shou-hua Zhu
Supersymmetric QCD corrections to lightest Higgs boson associated production with top quark pair at Linear Colliders
14 pages, 3 figs
null
null
null
hep-ph
null
Supersymmetric (SUSY) QCD corrections to the lightest neutral Higgs boson associated production with top quark pair are studied in the minimal supersymmetric standard model (MSSM) at Linear colliders. Our calculations show that the SUSY QCD effects generally are very moderate (say 10%) and under control, except for some rescattering effects which lead to a breakdown of perturbation theory and require a more detailed study. In the vicinity of the production threshold for the favorable model parameters under the framework of the on-shell renormalization scheme, SUSY QCD can be as large as about -50%. Such effects might be acted as the probe to determine the sign of $M_{LR}\equiv A_t-\mu/\tan\beta$.
[ { "created": "Wed, 18 Dec 2002 20:28:37 GMT", "version": "v1" }, { "created": "Tue, 20 May 2003 21:04:00 GMT", "version": "v2" }, { "created": "Tue, 17 Jun 2003 18:40:13 GMT", "version": "v3" }, { "created": "Fri, 26 Sep 2003 14:17:01 GMT", "version": "v4" } ]
2007-05-23
[ [ "Zhu", "Shou-hua", "" ] ]
Supersymmetric (SUSY) QCD corrections to the lightest neutral Higgs boson associated production with top quark pair are studied in the minimal supersymmetric standard model (MSSM) at Linear colliders. Our calculations show that the SUSY QCD effects generally are very moderate (say 10%) and under control, except for some rescattering effects which lead to a breakdown of perturbation theory and require a more detailed study. In the vicinity of the production threshold for the favorable model parameters under the framework of the on-shell renormalization scheme, SUSY QCD can be as large as about -50%. Such effects might be acted as the probe to determine the sign of $M_{LR}\equiv A_t-\mu/\tan\beta$.
hep-ph/9612494
Cristina Manuel
Cristina Manuel
Magnetic Screening at Finite Temperature
21 pages, RevTex; rewritten discussion, misleading sentences have been eliminated, results unchanged
Annals Phys. 263 (1998) 238-254
10.1006/aphy.1997.5763
ECM-UB-PF-96/24
hep-ph
null
It is shown that at finite temperature and in the presence of magnetic sources magnetic fields are screened. This is proven within the framework of classical transport theory both for the Abelian and non-Abelian plasmas. Magnetic screening arises in this formalism as a consequence of polarization effects occurring in the plasmas, and it is proportional to the inverse of the gauge coupling constant. It is then discussed whether this mechanism could be relevant in realistic quantum gauge field theories, such as QCD.
[ { "created": "Tue, 31 Dec 1996 11:58:20 GMT", "version": "v1" }, { "created": "Mon, 9 Jun 1997 16:11:19 GMT", "version": "v2" } ]
2009-10-30
[ [ "Manuel", "Cristina", "" ] ]
It is shown that at finite temperature and in the presence of magnetic sources magnetic fields are screened. This is proven within the framework of classical transport theory both for the Abelian and non-Abelian plasmas. Magnetic screening arises in this formalism as a consequence of polarization effects occurring in the plasmas, and it is proportional to the inverse of the gauge coupling constant. It is then discussed whether this mechanism could be relevant in realistic quantum gauge field theories, such as QCD.
hep-ph/0312109
Christian Bauer
Christian W. Bauer and Aneesh V. Manohar
Shape function effects in B -> X_s gamma and B -> X_u l nu decays
20 pages
Phys.Rev.D70:034024,2004
10.1103/PhysRevD.70.034024
CALT-68-2465
hep-ph
null
We calculate the decay distributions for inclusive B -> X_s gamma and B -> X_u l nu decays in the endpoint region, where radiative corrections are large. The computation is done using effective field theory methods. The matching coefficients are computed to O(alpha_s), and the anomalous dimensions to next-to-leading order. The final expressions for the differential decay spectra include the complete O(alpha_s) corrections, and sum the leading and next-to-leading Sudakov series. We present results for regions of phase space where the shape function can be expanded in local operators, and give the matching coefficients of the resulting enhanced non-perturbative effects to order alpha_s. We show that moments of the shape function {\it are not} given by moments of local operators once perturbative effects are included, explain why the shape function and its moments satisfy different renormalization group equations, and contrast this with the situation for deep inelastic scattering. We show that there are large perturbative corrections in the usual definition of the shape function. This renders incorrect previous prescriptions for combining radiative corrections with the shape function.
[ { "created": "Tue, 9 Dec 2003 20:16:43 GMT", "version": "v1" } ]
2011-05-05
[ [ "Bauer", "Christian W.", "" ], [ "Manohar", "Aneesh V.", "" ] ]
We calculate the decay distributions for inclusive B -> X_s gamma and B -> X_u l nu decays in the endpoint region, where radiative corrections are large. The computation is done using effective field theory methods. The matching coefficients are computed to O(alpha_s), and the anomalous dimensions to next-to-leading order. The final expressions for the differential decay spectra include the complete O(alpha_s) corrections, and sum the leading and next-to-leading Sudakov series. We present results for regions of phase space where the shape function can be expanded in local operators, and give the matching coefficients of the resulting enhanced non-perturbative effects to order alpha_s. We show that moments of the shape function {\it are not} given by moments of local operators once perturbative effects are included, explain why the shape function and its moments satisfy different renormalization group equations, and contrast this with the situation for deep inelastic scattering. We show that there are large perturbative corrections in the usual definition of the shape function. This renders incorrect previous prescriptions for combining radiative corrections with the shape function.
hep-ph/9905530
Noriaki Nakajima Nuclear Science Group
Katuhiko Suzuki(RCNP), Noriaki Nakajima(RCNP), H. Toki(RCNP) and K.-I. Kubo(Tokyo Metropolitan Univ.)
Analyzing powers in inclusive pion production at high energy and the nucleon spin structure
13 pages, 4 figures, latex
Mod.Phys.Lett.A14:1403-1412,1999
10.1142/S0217732399001504
null
hep-ph
null
Analyzing powers in inclusive pion production in high energy transversely polarized proton-proton collisions are studied theoretically in the framework of the quark recombination model. Calculations by assuming the SU(6) spin-flavor symmetry for the nucleon structure disagree with the experiments. We solve this difficulty by taking into account the %We overcome this difficulty by taking into account the realistic spin distribution functions of the nucleon, which differs from the SU(6) expectation at large $x$, %but coincides with a perturbative QCD constraint on the ratio of the unpolarized valence distributions, $u/d \to 5$ as $x \to 1$. We also discuss the kaon spin asymmetry and find $A_N(K^+) = -A_N(K^0)$ in the polarized proton-proton collisions at large $x_F$.
[ { "created": "Fri, 28 May 1999 08:01:44 GMT", "version": "v1" } ]
2014-11-17
[ [ "Suzuki", "Katuhiko", "", "RCNP" ], [ "Nakajima", "Noriaki", "", "RCNP" ], [ "Toki", "H.", "", "RCNP" ], [ "Kubo", "K. -I.", "", "Tokyo Metropolitan Univ." ] ]
Analyzing powers in inclusive pion production in high energy transversely polarized proton-proton collisions are studied theoretically in the framework of the quark recombination model. Calculations by assuming the SU(6) spin-flavor symmetry for the nucleon structure disagree with the experiments. We solve this difficulty by taking into account the %We overcome this difficulty by taking into account the realistic spin distribution functions of the nucleon, which differs from the SU(6) expectation at large $x$, %but coincides with a perturbative QCD constraint on the ratio of the unpolarized valence distributions, $u/d \to 5$ as $x \to 1$. We also discuss the kaon spin asymmetry and find $A_N(K^+) = -A_N(K^0)$ in the polarized proton-proton collisions at large $x_F$.
1206.5612
Conrado Albertus-Torres
C. Albertus, E. Hernandez, J. Nieves
Semileptonic decays of spin-1/2 doubly charmed baryons
Talk given at the QNP 2012. To appear in the proceedings
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate exclusive semileptonic decays of ground-state spin-1/2 doubly heavy charmed baryons. The decays are driven by a $c\to s,d$ transition at the quark level. Our form factors are consistent with Heavy Quark Symmetry constraints. The latter are valid in the limit of infinitely heavy quark mass at zero recoil.
[ { "created": "Mon, 25 Jun 2012 09:09:35 GMT", "version": "v1" } ]
2012-06-26
[ [ "Albertus", "C.", "" ], [ "Hernandez", "E.", "" ], [ "Nieves", "J.", "" ] ]
We evaluate exclusive semileptonic decays of ground-state spin-1/2 doubly heavy charmed baryons. The decays are driven by a $c\to s,d$ transition at the quark level. Our form factors are consistent with Heavy Quark Symmetry constraints. The latter are valid in the limit of infinitely heavy quark mass at zero recoil.
1910.14038
Gherardo Vita
Ian Moult, Iain W. Stewart, Gherardo Vita and Hua Xing Zhu
The Soft Quark Sudakov
21 pages, many beautiful figures. v2: journal version, added appendices
null
10.1007/JHEP05(2020)089
MIT-CTP 5156
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There has been recent interest in understanding the all loop structure of the subleading power soft and collinear limits, with the goal of achieving a systematic resummation of subleading power infrared logarithms. Most of this work has focused on subleading power corrections to soft gluon emission, whose form is strongly constrained by symmetries. In this paper we initiate a study of the all loop structure of soft fermion emission. In $\mathcal{N}=1$ QCD we perform an operator based factorization and resummation of the associated infrared logarithms, and prove that they exponentiate into a Sudakov due to their relation to soft gluon emission. We verify this result through explicit calculation to $\mathcal{O}(\alpha_s^3)$. We show that in QCD, this simple Sudakov exponentiation is violated by endpoint contributions proportional to $(C_A-C_F)^n$ which contribute at leading logarithmic order. Combining our $\mathcal{N}=1$ result and our calculation of the endpoint contributions to $\mathcal{O}(\alpha_s^3)$, we conjecture a result for the soft quark Sudakov in QCD, a new all orders function first appearing at subleading power, and give evidence for its universality. Our result, which is expressed in terms of combinations of cusp anomalous dimensions in different color representations, takes an intriguingly simple form and also exhibits interesting similarities to results for large-x logarithms in the off diagonal splitting functions.
[ { "created": "Wed, 30 Oct 2019 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 4 May 2020 20:55:25 GMT", "version": "v2" } ]
2020-06-24
[ [ "Moult", "Ian", "" ], [ "Stewart", "Iain W.", "" ], [ "Vita", "Gherardo", "" ], [ "Zhu", "Hua Xing", "" ] ]
There has been recent interest in understanding the all loop structure of the subleading power soft and collinear limits, with the goal of achieving a systematic resummation of subleading power infrared logarithms. Most of this work has focused on subleading power corrections to soft gluon emission, whose form is strongly constrained by symmetries. In this paper we initiate a study of the all loop structure of soft fermion emission. In $\mathcal{N}=1$ QCD we perform an operator based factorization and resummation of the associated infrared logarithms, and prove that they exponentiate into a Sudakov due to their relation to soft gluon emission. We verify this result through explicit calculation to $\mathcal{O}(\alpha_s^3)$. We show that in QCD, this simple Sudakov exponentiation is violated by endpoint contributions proportional to $(C_A-C_F)^n$ which contribute at leading logarithmic order. Combining our $\mathcal{N}=1$ result and our calculation of the endpoint contributions to $\mathcal{O}(\alpha_s^3)$, we conjecture a result for the soft quark Sudakov in QCD, a new all orders function first appearing at subleading power, and give evidence for its universality. Our result, which is expressed in terms of combinations of cusp anomalous dimensions in different color representations, takes an intriguingly simple form and also exhibits interesting similarities to results for large-x logarithms in the off diagonal splitting functions.
2001.04788
Avelino Vicente
Avelino Vicente
Theory status and implications of $R_K^{(\ast)}$
Contribution to the proceedings of the 18th International Conference on B-Physics at Frontier Machines (Beauty 2019), Ljubljana, Slovenia, September 30 - October 4, 2019
null
null
IFIC/20-03
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHCb and Belle collaborations have reported on some anomalies in $b \to s$ transitions, with discrepancies with the Standard Model predictions in some angular observables and branching ratios and intriguing hints for lepton universality violation. We will review the current situation and explore the proposed New Physics explanations for these tensions. We will also discuss the possible connection of the $b \to s$ anomalies to other central problems in physics, such as the dark matter of the Universe, the origin of neutrino masses or the strong CP problem.
[ { "created": "Tue, 14 Jan 2020 14:13:44 GMT", "version": "v1" } ]
2020-01-15
[ [ "Vicente", "Avelino", "" ] ]
The LHCb and Belle collaborations have reported on some anomalies in $b \to s$ transitions, with discrepancies with the Standard Model predictions in some angular observables and branching ratios and intriguing hints for lepton universality violation. We will review the current situation and explore the proposed New Physics explanations for these tensions. We will also discuss the possible connection of the $b \to s$ anomalies to other central problems in physics, such as the dark matter of the Universe, the origin of neutrino masses or the strong CP problem.
2104.10390
Hyun Min Lee
Hyun Min Lee, Adriana G. Menkara
Cosmology of Linear Higgs-Sigma Models with Conformal Invariance
24 pages, 3 figures, v2: Accepted for JHEP, discussion expanded on perturbativity conditions for UV complete models and references added
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
We consider general linear Higgs-sigma models as ultra-violet completions of the Higgs inflation. We introduce general higher curvature terms beyond Einstein gravity and recast them into a class of linear Higgs-sigma models in the scalar-dual formulation where conformal symmetry is manifest. Integrating out the sigma field in this class of linear sigma models, we obtain the same Higgs inflation Lagrangian of non-linear sigma model type in the effective theory. We show that the successful inflation for sigma field singles out the sigma-field potential derived from the $R^2$ term and the tracker solution for dark energy at late times can be realized for the $R^{p+1}$ term with $-1<p<0$. We also discuss the implications of Higgs-sigma interactions for the inflation and the vacuum stability in the Standard Model.
[ { "created": "Wed, 21 Apr 2021 07:24:36 GMT", "version": "v1" }, { "created": "Mon, 16 Aug 2021 12:47:21 GMT", "version": "v2" } ]
2021-08-17
[ [ "Lee", "Hyun Min", "" ], [ "Menkara", "Adriana G.", "" ] ]
We consider general linear Higgs-sigma models as ultra-violet completions of the Higgs inflation. We introduce general higher curvature terms beyond Einstein gravity and recast them into a class of linear Higgs-sigma models in the scalar-dual formulation where conformal symmetry is manifest. Integrating out the sigma field in this class of linear sigma models, we obtain the same Higgs inflation Lagrangian of non-linear sigma model type in the effective theory. We show that the successful inflation for sigma field singles out the sigma-field potential derived from the $R^2$ term and the tracker solution for dark energy at late times can be realized for the $R^{p+1}$ term with $-1<p<0$. We also discuss the implications of Higgs-sigma interactions for the inflation and the vacuum stability in the Standard Model.
hep-ph/9308244
null
Patricia Ball
The Decay $B\to K^*\gamma$ from QCD Sum Rules
8 ps, 2 uuencoded PS figures included, requires epsf.sty and revtex3, TUM-T31-43/93
null
null
null
hep-ph
null
Using the QCD sum rules approach and the complete leading--logarithmic short--distance coefficients determining the penguin--amplitude, we obtain $B(B\to K^*\gamma) = (6.8\pm 2.4)\cdot 10^{-5}$ for top--quark masses in the range (150--200) GeV and $|V_{cb}| = 0.035$ for $\tau_B = 1.5\,\text{ps}$. The ratio to the inclusive rate is $B(B\to K^*\gamma)/B(B\to X_s\gamma) = (20\pm 6)\% $.
[ { "created": "Sat, 7 Aug 1993 22:19:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ball", "Patricia", "" ] ]
Using the QCD sum rules approach and the complete leading--logarithmic short--distance coefficients determining the penguin--amplitude, we obtain $B(B\to K^*\gamma) = (6.8\pm 2.4)\cdot 10^{-5}$ for top--quark masses in the range (150--200) GeV and $|V_{cb}| = 0.035$ for $\tau_B = 1.5\,\text{ps}$. The ratio to the inclusive rate is $B(B\to K^*\gamma)/B(B\to X_s\gamma) = (20\pm 6)\% $.
hep-ph/9710436
Guy Moore
Guy D. Moore, Chaoran Hu, and Berndt Muller
Chern-Simons number diffusion with hard thermal loops
43 pages including 8 figures. Added discussion, very minor changes
Phys. Rev. D 58, 045001 (1998)
10.1103/PhysRevD.58.045001
PUPT-1713, MCGILL-97/24, DUKE-TH-97-154
hep-ph
null
We construct an extension of the standard Kogut-Susskind lattice model for classical 3+1 dimensional Yang-Mills theory, in which ``classical particle'' degrees of freedom are added. We argue that this will correctly reproduce the ``hard thermal loop'' effects of hard degrees of freedom, while giving a local implementation which is numerically tractable. We prove that the extended system is Hamiltonian and has the same thermodynamics as dimensionally reduced hot Yang-Mills theory put on a lattice. We present a numerical update algorithm and study the abelian theory to verify that the classical gauge theory self-energy is correctly modified. Then we use the extended system to study the diffusion constant for Chern-Simons number. We verify the Arnold-Son-Yaffe picture that the diffusion constant is inversely proportional to hard thermal loop strength. Our numbers correspond to a diffusion constant of Gamma = 29 +- 6 alpha_w^5 T^4 for m_D^2 = 11 g^2 T^2/6.
[ { "created": "Wed, 22 Oct 1997 15:13:25 GMT", "version": "v1" }, { "created": "Tue, 3 Feb 1998 20:22:31 GMT", "version": "v2" } ]
2016-08-25
[ [ "Moore", "Guy D.", "" ], [ "Hu", "Chaoran", "" ], [ "Muller", "Berndt", "" ] ]
We construct an extension of the standard Kogut-Susskind lattice model for classical 3+1 dimensional Yang-Mills theory, in which ``classical particle'' degrees of freedom are added. We argue that this will correctly reproduce the ``hard thermal loop'' effects of hard degrees of freedom, while giving a local implementation which is numerically tractable. We prove that the extended system is Hamiltonian and has the same thermodynamics as dimensionally reduced hot Yang-Mills theory put on a lattice. We present a numerical update algorithm and study the abelian theory to verify that the classical gauge theory self-energy is correctly modified. Then we use the extended system to study the diffusion constant for Chern-Simons number. We verify the Arnold-Son-Yaffe picture that the diffusion constant is inversely proportional to hard thermal loop strength. Our numbers correspond to a diffusion constant of Gamma = 29 +- 6 alpha_w^5 T^4 for m_D^2 = 11 g^2 T^2/6.
hep-ph/0210414
We-Fu Chang
We-Fu Chang and John N. Ng (TRIUMF)
CP violation in 5D Split Fermions Scenario
24 pages, 8 figures
JHEP 0212:077,2002
10.1088/1126-6708/2002/12/077
null
hep-ph
null
We give a new configuration of split fermion positions in one extra dimension with two different Yukawa coupling strengths for up-type, $h_u$, and down-type, $h_d$, quarks at $\frac{h_u}{h_d}=36.0$. The new configurations can give enough CP violating (CPV) phase for accommodating all currently observed CPV processes. Therefore, a 5D standard model with split fermions is viable. In addition to the standard CKM phase, new CPV sources involving Kaluza-Klein(KK) gauge bosons coupling which arise from the fact that unitary rotation which transforms weak eigenstates into their mass eigenstates only holds for the zero modes which are the SM fields and not for the KK excitations. We have examined the physics of kaon, neutron, and $B/D$ mesons and found the most stringent bound on the size $R$ of the extra dimension comes from $|\epsilon_K|$. Moreover, it depends sensitively on the width, $\sigma$, of the Gaussian wavefunction in the extra dimension used to describe of the fermions. When $\sigma/R \ll 1$, the constraint will be lifted due to GIM suppression on the flavor changing neutral current(FCNC) and CPV couplings.
[ { "created": "Tue, 29 Oct 2002 23:36:20 GMT", "version": "v1" } ]
2011-02-01
[ [ "Chang", "We-Fu", "", "TRIUMF" ], [ "Ng", "John N.", "", "TRIUMF" ] ]
We give a new configuration of split fermion positions in one extra dimension with two different Yukawa coupling strengths for up-type, $h_u$, and down-type, $h_d$, quarks at $\frac{h_u}{h_d}=36.0$. The new configurations can give enough CP violating (CPV) phase for accommodating all currently observed CPV processes. Therefore, a 5D standard model with split fermions is viable. In addition to the standard CKM phase, new CPV sources involving Kaluza-Klein(KK) gauge bosons coupling which arise from the fact that unitary rotation which transforms weak eigenstates into their mass eigenstates only holds for the zero modes which are the SM fields and not for the KK excitations. We have examined the physics of kaon, neutron, and $B/D$ mesons and found the most stringent bound on the size $R$ of the extra dimension comes from $|\epsilon_K|$. Moreover, it depends sensitively on the width, $\sigma$, of the Gaussian wavefunction in the extra dimension used to describe of the fermions. When $\sigma/R \ll 1$, the constraint will be lifted due to GIM suppression on the flavor changing neutral current(FCNC) and CPV couplings.
1708.00867
Wouter Waalewijn
Jonathan Mo, Frank J. Tackmann, Wouter J. Waalewijn
A case study of quark-gluon discrimination at NNLL' in comparison to parton showers
10 pages, 5 figures
null
10.1140/epjc/s10052-017-5365-9
DESY 17-111, NIKHEF 2017-031
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Predictions for our ability to distinguish quark and gluon jets vary by more than a factor of two between different parton showers. We study this problem using analytic resummed predictions for the thrust event shape up to NNLL' using $e^+e^- \to Z \to q \bar q$ and $e^+e^- \to H \to gg$ as proxies for quark and gluon jets. We account for hadronization effects through a nonperturbative shape function, and include an estimate of both perturbative and hadronization uncertainties. In contrast to previous studies, we find reasonable agreement between our results and predictions from both Pythia and Herwig parton showers. We find that this is due to a noticeable improvement in the description of gluon jets in the newest Herwig 7.1 compared to previous versions.
[ { "created": "Wed, 2 Aug 2017 18:00:02 GMT", "version": "v1" } ]
2017-12-06
[ [ "Mo", "Jonathan", "" ], [ "Tackmann", "Frank J.", "" ], [ "Waalewijn", "Wouter J.", "" ] ]
Predictions for our ability to distinguish quark and gluon jets vary by more than a factor of two between different parton showers. We study this problem using analytic resummed predictions for the thrust event shape up to NNLL' using $e^+e^- \to Z \to q \bar q$ and $e^+e^- \to H \to gg$ as proxies for quark and gluon jets. We account for hadronization effects through a nonperturbative shape function, and include an estimate of both perturbative and hadronization uncertainties. In contrast to previous studies, we find reasonable agreement between our results and predictions from both Pythia and Herwig parton showers. We find that this is due to a noticeable improvement in the description of gluon jets in the newest Herwig 7.1 compared to previous versions.
hep-ph/0012348
Jianwei Qiu
Jianwei Qiu and Xiaofei Zhang (Iowa State University)
Role of the nonperturbative input in QCD resummed Drell-Yan $Q_T$-distributions
Latex, 43 pages including 15 figures; typos were corrected
Phys.Rev.D63:114011,2001
10.1103/PhysRevD.63.114011
null
hep-ph nucl-th
null
We analyze the role of the nonperturbative input in the Collins, Soper, and Sterman (CSS)'s $b$-space QCD resummation formalism for Drell-Yan transverse momentum ($Q_T$) distributions, and investigate the predictive power of the CSS formalism. We find that the predictive power of the CSS formalism has a strong dependence on the collision energy $\sqrt{S}$ in addition to its well-known $Q^2$ dependence, and the $\sqrt{S}$ dependence improves the predictive power at collider energies. We show that a reliable extrapolation from perturbatively resummed $b$-space distributions to the nonperturbative large $b$ region is necessary to ensure the correct $Q_T$ distributions. By adding power corrections to the renormalization group equations in the CSS formalism, we derive a new extrapolation formalism. We demonstrate that at collider energies, the CSS resummation formalism plus our extrapolation has an excellent predictive power for $W$ and $Z$ production at all transverse momenta $Q_T\le Q$. We also show that the $b$-space resummed $Q_T$ distributions provide a good description of Drell-Yan data at fixed target energies.
[ { "created": "Wed, 27 Dec 2000 18:20:20 GMT", "version": "v1" }, { "created": "Tue, 20 Feb 2001 15:59:16 GMT", "version": "v2" } ]
2008-11-26
[ [ "Qiu", "Jianwei", "", "Iowa State University" ], [ "Zhang", "Xiaofei", "", "Iowa State University" ] ]
We analyze the role of the nonperturbative input in the Collins, Soper, and Sterman (CSS)'s $b$-space QCD resummation formalism for Drell-Yan transverse momentum ($Q_T$) distributions, and investigate the predictive power of the CSS formalism. We find that the predictive power of the CSS formalism has a strong dependence on the collision energy $\sqrt{S}$ in addition to its well-known $Q^2$ dependence, and the $\sqrt{S}$ dependence improves the predictive power at collider energies. We show that a reliable extrapolation from perturbatively resummed $b$-space distributions to the nonperturbative large $b$ region is necessary to ensure the correct $Q_T$ distributions. By adding power corrections to the renormalization group equations in the CSS formalism, we derive a new extrapolation formalism. We demonstrate that at collider energies, the CSS resummation formalism plus our extrapolation has an excellent predictive power for $W$ and $Z$ production at all transverse momenta $Q_T\le Q$. We also show that the $b$-space resummed $Q_T$ distributions provide a good description of Drell-Yan data at fixed target energies.
1404.5343
Herm\`es B\'elusca-Ma\"ito
Hermes Belusca-Maito
Effective Higgs Lagrangian and Constraints on Higgs Couplings
34 pages, 6 figures; v2: some issues clarified, updated references, updated fit with latest data from Run-I of ATLAS and CMS (see text for details)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Probing the properties of the discovered Higgs boson may tell us whether or not it is the same particle as the one predicted by the Standard Model. To this aim we parametrize deviations of the Higgs couplings to matter from the Standard Model by using the Higgs Effective Field Theory framework. Starting with a general dimension-6 effective Lagrangian including both CP-even and CP-odd operators, and requiring that the operators do not introduce power divergences in the oblique parameters, we reduce the number of independent effective couplings of the theory. This framework is then used to put updated constraints on the effective couplings, using the latest Higgs rates data from the Run-I of the ATLAS and CMS experiments, and electroweak precision data from LEP, SLC and Tevatron. We show that the current data is able to significantly constrain the CP-even and some CP-odd operators of the effective Lagrangian.
[ { "created": "Mon, 21 Apr 2014 22:10:00 GMT", "version": "v1" }, { "created": "Tue, 29 Dec 2015 01:30:28 GMT", "version": "v2" } ]
2016-02-22
[ [ "Belusca-Maito", "Hermes", "" ] ]
Probing the properties of the discovered Higgs boson may tell us whether or not it is the same particle as the one predicted by the Standard Model. To this aim we parametrize deviations of the Higgs couplings to matter from the Standard Model by using the Higgs Effective Field Theory framework. Starting with a general dimension-6 effective Lagrangian including both CP-even and CP-odd operators, and requiring that the operators do not introduce power divergences in the oblique parameters, we reduce the number of independent effective couplings of the theory. This framework is then used to put updated constraints on the effective couplings, using the latest Higgs rates data from the Run-I of the ATLAS and CMS experiments, and electroweak precision data from LEP, SLC and Tevatron. We show that the current data is able to significantly constrain the CP-even and some CP-odd operators of the effective Lagrangian.
1112.1367
Ernest Ma
Ernest Ma (UC Riverside)
Supersymmetric Axion-Neutrino Model with a Higgs Hybrid
9 pages, no figure
Int. J. Mod. Phys. A 27, 1250059 (2012)
10.1142/S0217751X12500595
UCRHEP-T513 (December 2011)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In 2001, a supersymmetric model was proposed to relate the axion scale to that of neutrino mass seesaw. Whereas this scenario is realistic, the particles associated with this mechanism are either too heavy or too weakly coupled for them to be observed (other than the axion itself or perhaps the axino). A variation of that model is here proposed which allows significant mixing of the Higgs boson with a new singlet related to the saxion (the scalar partner of the pseudoscalar axion), rendering it possible to be observed at the Large Hadron Collider (LHC). With the addition of exotic color superfields, this also becomes a specific realization of how the production of such a Higgs hybrid may be suppressed or enhanced at the LHC, which is very relevant to ongoing experimental efforts to find the Higgs boson.
[ { "created": "Tue, 6 Dec 2011 18:29:04 GMT", "version": "v1" }, { "created": "Fri, 4 May 2012 16:49:18 GMT", "version": "v2" } ]
2015-06-03
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
In 2001, a supersymmetric model was proposed to relate the axion scale to that of neutrino mass seesaw. Whereas this scenario is realistic, the particles associated with this mechanism are either too heavy or too weakly coupled for them to be observed (other than the axion itself or perhaps the axino). A variation of that model is here proposed which allows significant mixing of the Higgs boson with a new singlet related to the saxion (the scalar partner of the pseudoscalar axion), rendering it possible to be observed at the Large Hadron Collider (LHC). With the addition of exotic color superfields, this also becomes a specific realization of how the production of such a Higgs hybrid may be suppressed or enhanced at the LHC, which is very relevant to ongoing experimental efforts to find the Higgs boson.
hep-ph/9908241
Vivian Demetriou
P. Demetriou, S. Boffi, M. Radici and R. F. Wagenbrunn
Nucleon Electromagnetic Form Factors in a chiral constituent-quark model
LateX2e, requires sprocl.sty, 10 pages, 2 figures embedded, talk given at Int. Conference on Perspectives in Hadronic Physics, ICTP Trieste, 10-14 May 1999
null
null
null
hep-ph nucl-th
null
The electromagnetic form factors of the nucleon are calculated in an extended chiral constituent-quark model where the effective interaction is described by the exchange of pseudoscalar, vector, and scalar mesons. Two-body current-density operators, constructed consistently with the extended model Hamiltonian in order to preserve gauge invariance and current conservation, are found to give a significant contribution to the nucleon magnetic form factors and improve the estimates of the nucleon magnetic moments.
[ { "created": "Wed, 4 Aug 1999 09:54:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Demetriou", "P.", "" ], [ "Boffi", "S.", "" ], [ "Radici", "M.", "" ], [ "Wagenbrunn", "R. F.", "" ] ]
The electromagnetic form factors of the nucleon are calculated in an extended chiral constituent-quark model where the effective interaction is described by the exchange of pseudoscalar, vector, and scalar mesons. Two-body current-density operators, constructed consistently with the extended model Hamiltonian in order to preserve gauge invariance and current conservation, are found to give a significant contribution to the nucleon magnetic form factors and improve the estimates of the nucleon magnetic moments.
1205.0067
Boris Kopeliovich
B.Z. Kopeliovich, I.K. Potashnikova, B. Povh and Ivan Schmidt
Pion structure function at small x from DIS data
17 pages, 12 figures
null
10.1103/PhysRevD.85.114025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Production of leading neutrons in DIS is usually considered as a tool to measure the pion structure function at small x accessible at HERA. The main obstacle is the lack of reliable evaluations of the absorption corrections, which significantly suppress the cross section. We performed a parameter free calculation within the dipole approach and found the absorption corrections to be nearly as strong, as for neutron production in pp collisions. We also included the significant contribution of the iso-vector Reggeons with natural (\rho, a_2) and unnatural (a_1, \rho-\pi\ cut) parity with parameters constrained by phenomenology. With a certain modeling for the pion-to-proton ratio of the structure functions we reached good agreement with data from the ZEUS and H1 experiments, successfully reproducing the observed dependence on the fractional neutron momentum z, the photon virtuality Q^2, and the transverse momentum transfer q_T.
[ { "created": "Tue, 1 May 2012 01:40:12 GMT", "version": "v1" } ]
2013-05-30
[ [ "Kopeliovich", "B. Z.", "" ], [ "Potashnikova", "I. K.", "" ], [ "Povh", "B.", "" ], [ "Schmidt", "Ivan", "" ] ]
Production of leading neutrons in DIS is usually considered as a tool to measure the pion structure function at small x accessible at HERA. The main obstacle is the lack of reliable evaluations of the absorption corrections, which significantly suppress the cross section. We performed a parameter free calculation within the dipole approach and found the absorption corrections to be nearly as strong, as for neutron production in pp collisions. We also included the significant contribution of the iso-vector Reggeons with natural (\rho, a_2) and unnatural (a_1, \rho-\pi\ cut) parity with parameters constrained by phenomenology. With a certain modeling for the pion-to-proton ratio of the structure functions we reached good agreement with data from the ZEUS and H1 experiments, successfully reproducing the observed dependence on the fractional neutron momentum z, the photon virtuality Q^2, and the transverse momentum transfer q_T.
2309.05407
Ernesto Arganda
Ernesto Arganda, Daniel A. D\'iaz, Andres D. Perez, Rosa M. Sand\'a Seoane, and Alejandro Szynkman
LHC Study of Third-Generation Scalar Leptoquarks with Machine-Learned Likelihoods
25 pages, 7 figures, 2 tables (version published in PRD). Unbinned method code with approach to systematic uncertainty inclusion available from https://github.com/AndresDanielPerez/
null
null
IFT-UAM/CSIC-23-110
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the impact of machine-learning algorithms on LHC searches for leptoquarks in final states with hadronically decaying tau leptons, multiple $b$-jets, and large missing transverse momentum. Pair production of scalar leptoquarks with decays only into third-generation leptons and quarks is assumed. Thanks to the use of supervised learning tools with unbinned methods to handle the high-dimensional final states, we consider simple selection cuts which would possibly translate into an improvement in the exclusion limits at the 95$\%$ confidence level for leptoquark masses with different values of their branching fraction into charged leptons. In particular, for intermediate branching fractions, we expect that the exclusion limits for leptoquark masses extend to $\sim$1.3 TeV. As a novelty in the implemented unbinned analysis, we include a simplified estimation of some systematic uncertainties with the aim of studying their possible impact on the stability of the results. Finally, we also present the projected sensitivity within this framework at 14 TeV for 300 and 3000 fb$^{-1}$ that extends the upper limits to $\sim$1.6 and $\sim$1.8 TeV, respectively.
[ { "created": "Mon, 11 Sep 2023 12:12:57 GMT", "version": "v1" }, { "created": "Mon, 11 Mar 2024 15:10:32 GMT", "version": "v2" } ]
2024-03-12
[ [ "Arganda", "Ernesto", "" ], [ "Díaz", "Daniel A.", "" ], [ "Perez", "Andres D.", "" ], [ "Seoane", "Rosa M. Sandá", "" ], [ "Szynkman", "Alejandro", "" ] ]
We study the impact of machine-learning algorithms on LHC searches for leptoquarks in final states with hadronically decaying tau leptons, multiple $b$-jets, and large missing transverse momentum. Pair production of scalar leptoquarks with decays only into third-generation leptons and quarks is assumed. Thanks to the use of supervised learning tools with unbinned methods to handle the high-dimensional final states, we consider simple selection cuts which would possibly translate into an improvement in the exclusion limits at the 95$\%$ confidence level for leptoquark masses with different values of their branching fraction into charged leptons. In particular, for intermediate branching fractions, we expect that the exclusion limits for leptoquark masses extend to $\sim$1.3 TeV. As a novelty in the implemented unbinned analysis, we include a simplified estimation of some systematic uncertainties with the aim of studying their possible impact on the stability of the results. Finally, we also present the projected sensitivity within this framework at 14 TeV for 300 and 3000 fb$^{-1}$ that extends the upper limits to $\sim$1.6 and $\sim$1.8 TeV, respectively.
2310.15532
Hongxin Dong
Chunhua Zeng, Hongxin Dong, Tianbo Liu, Peng Sun and Yuxiang Zhao
Role of sea quarks in the nucleon transverse spin
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a phenomenological extraction of transversity distribution functions and Collins fragmentation functions by simultaneously fitting to semi-inclusive deep inelastic scattering and electron-positron annihilation data. The analysis is performed within the transverse momentum dependent factorization formalism, and sea quark transversity distributions are taken into account for the first time. We find the $\bar u$ quark favors a negative transversity distribution while that of the $\bar d$ quark is consistent with zero according to the current accuracy. In addition, based on a combined analysis of world data and simulated data, we quantitatively demonstrate the impact of the proposed Electron-ion Collider in China on precise determinations of the transversity distributions, especially for sea quarks, and the Collins fragmentation functions.
[ { "created": "Tue, 24 Oct 2023 05:36:53 GMT", "version": "v1" } ]
2023-10-25
[ [ "Zeng", "Chunhua", "" ], [ "Dong", "Hongxin", "" ], [ "Liu", "Tianbo", "" ], [ "Sun", "Peng", "" ], [ "Zhao", "Yuxiang", "" ] ]
We present a phenomenological extraction of transversity distribution functions and Collins fragmentation functions by simultaneously fitting to semi-inclusive deep inelastic scattering and electron-positron annihilation data. The analysis is performed within the transverse momentum dependent factorization formalism, and sea quark transversity distributions are taken into account for the first time. We find the $\bar u$ quark favors a negative transversity distribution while that of the $\bar d$ quark is consistent with zero according to the current accuracy. In addition, based on a combined analysis of world data and simulated data, we quantitatively demonstrate the impact of the proposed Electron-ion Collider in China on precise determinations of the transversity distributions, especially for sea quarks, and the Collins fragmentation functions.
hep-ph/0406075
Singh N. Nimai
N. Nimai Singh (1,2), Mahadev Patgiri (3) and Mrinal Kumar Das (2) ((1) The Abdus Salam ICTP, Trieste, Italy, (2) Gauhati University, (3) Cotton College)
Discriminating neutrino mass models using Type II seesaw formula
No change in the results, a few references added, some changes in Type[IIB] calculations
Pramana66:361-376,2006
10.1007/BF02704390
null
hep-ph
null
In this paper we propose a kind of natural selection which can discriminate the three possible neutrino mass models, namely the degenerate, inverted hierarchical and normal hierarchical models, using the framework of Type II seesaw formula. We arrive at a conclusion that the inverted hierarchical model appears to be most favourable whereas the normal hierarchical model follows next to it. The degenerate model is found to be most unfavourable. We use the hypothesis that those neutrino mass models in which Type I seesaw term dominates over the Type II left-handed Higgs triplet term are favoured to survive in nature.
[ { "created": "Mon, 7 Jun 2004 07:50:15 GMT", "version": "v1" }, { "created": "Tue, 20 Jul 2004 14:43:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Singh", "N. Nimai", "" ], [ "Patgiri", "Mahadev", "" ], [ "Das", "Mrinal Kumar", "" ] ]
In this paper we propose a kind of natural selection which can discriminate the three possible neutrino mass models, namely the degenerate, inverted hierarchical and normal hierarchical models, using the framework of Type II seesaw formula. We arrive at a conclusion that the inverted hierarchical model appears to be most favourable whereas the normal hierarchical model follows next to it. The degenerate model is found to be most unfavourable. We use the hypothesis that those neutrino mass models in which Type I seesaw term dominates over the Type II left-handed Higgs triplet term are favoured to survive in nature.
hep-ph/9604396
Mikhail Volkov
D.Ebert (Humboldt University, Berlin, Germany), M.K.Volkov (JINR, Dubna, Russia)
Kaon polarizability in the Nambu-Jona-Lasinio model at zero and finite temperature
14pages in LaTeX+3 uuencode postscript figures
Phys.Atom.Nucl.60:796-803,1997; Yad.Fiz.60N5:891-899,1997
null
JINR preprint E2-96-119
hep-ph
null
Using recent data for the decays $f_0 \to \gamma\gamma$, $f_0 \to \pi \pi$, we determine the mixing angle of scalar mesons in a chiral quark $\sigma$-model. This value is employed to analyze of the kaon polarizability. It is shown that pole diagrams from intermediate scalar mesons and their mixing angle significantly affect the electromagnetic polarizability of charged and neutral kaons. Our results are compared with other models and the results of the chiral symmetry limit. The temperature dependence of the kaon polarizabilities is investigated.
[ { "created": "Wed, 24 Apr 1996 13:04:54 GMT", "version": "v1" }, { "created": "Thu, 25 Apr 1996 17:13:31 GMT", "version": "v2" } ]
2010-11-15
[ [ "Ebert", "D.", "", "Humboldt University, Berlin, Germany" ], [ "Volkov", "M. K.", "", "JINR,\n Dubna, Russia" ] ]
Using recent data for the decays $f_0 \to \gamma\gamma$, $f_0 \to \pi \pi$, we determine the mixing angle of scalar mesons in a chiral quark $\sigma$-model. This value is employed to analyze of the kaon polarizability. It is shown that pole diagrams from intermediate scalar mesons and their mixing angle significantly affect the electromagnetic polarizability of charged and neutral kaons. Our results are compared with other models and the results of the chiral symmetry limit. The temperature dependence of the kaon polarizabilities is investigated.
hep-ph/0301272
Dilip Ghosh
N. G. Deshpande, Dilip Kumar Ghosh
Higgs pair production in association with a vector boson at e+e- colliders in theories of higher dimensional gravity
One new reference is added, some minor corrections, version to appear in Physical Review D
Phys.Rev. D67 (2003) 113006
10.1103/PhysRevD.67.113006
null
hep-ph
null
The models of large extra compact dimensions, as suggested by Arkani-Hamed, Dimopoulos and Dvali, predict exciting phenomenological consequences with gravitational interactions becoming strong at the TeV scale. Such theories can be tested at the existing and future colliders. In this paper, we study the contribution of virtual Kaluza-Klein excitations (both spin-0 and 2) in the process $e^+e^- \to HHZ$ and $ e^+e^- \to HH\gamma $ at future linear collider (NLC). We find that the virtual exchange KK gravitons can modify the cross-section $\sigma(e^+e^- \to HHZ)$ significantly from its Standard Model value and will allow the effective string scale to be probed up to 6.6 TeV. The second process is absent at the tree level in the standard model, and can therefore be used to put limits on the effective string scale of 7.4 TeV.
[ { "created": "Fri, 31 Jan 2003 16:31:40 GMT", "version": "v1" }, { "created": "Tue, 22 Apr 2003 21:32:31 GMT", "version": "v2" } ]
2009-11-10
[ [ "Deshpande", "N. G.", "" ], [ "Ghosh", "Dilip Kumar", "" ] ]
The models of large extra compact dimensions, as suggested by Arkani-Hamed, Dimopoulos and Dvali, predict exciting phenomenological consequences with gravitational interactions becoming strong at the TeV scale. Such theories can be tested at the existing and future colliders. In this paper, we study the contribution of virtual Kaluza-Klein excitations (both spin-0 and 2) in the process $e^+e^- \to HHZ$ and $ e^+e^- \to HH\gamma $ at future linear collider (NLC). We find that the virtual exchange KK gravitons can modify the cross-section $\sigma(e^+e^- \to HHZ)$ significantly from its Standard Model value and will allow the effective string scale to be probed up to 6.6 TeV. The second process is absent at the tree level in the standard model, and can therefore be used to put limits on the effective string scale of 7.4 TeV.
1507.08143
Felipe J. Llanes-Estrada
Guillermo Garcia Fernandez, Jesus Guerrero Rojas and Felipe J. Llanes-Estrada (U. Complutense Madrid)
Spontaneous mass generation and the small dimensions of the Standard Model gauge groups U(1), SU(2) and SU(3)
15 pages, 17 plots. This version incorporates community as well as referee comments. Accepted for publication in Nuclear Physics B
Nucl. Phys. B 915 (2017) 262-284
10.1016/j.nuclphysb.2016.12.010
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gauge symmetry of the Standard Model is SU(3)_c x SU(2)_L x U(1)_Y for unknown reasons. One aspect that can be addressed is the low dimensionality of all its subgroups. Why not much larger groups like SU(7), or for that matter, SP(38) or E7? We observe that fermions charged under large groups acquire much bigger dynamical masses, all things being equal at a high e.g. GUT scale, than ordinary quarks. Should such multicharged fermions exist, they are too heavy to be observed today and have either decayed early on (if they couple to the rest of the Standard Model) or become reliquial dark matter (if they don't). The result follows from strong antiscreening of the running coupling for those larger groups (with an appropriately small number of flavors) together with scaling properties of the Dyson-Schwinger equation for the fermion mass.
[ { "created": "Wed, 29 Jul 2015 13:43:21 GMT", "version": "v1" }, { "created": "Tue, 13 Dec 2016 19:12:48 GMT", "version": "v2" } ]
2016-12-30
[ [ "Fernandez", "Guillermo Garcia", "", "U. Complutense Madrid" ], [ "Rojas", "Jesus Guerrero", "", "U. Complutense Madrid" ], [ "Llanes-Estrada", "Felipe J.", "", "U. Complutense Madrid" ] ]
The gauge symmetry of the Standard Model is SU(3)_c x SU(2)_L x U(1)_Y for unknown reasons. One aspect that can be addressed is the low dimensionality of all its subgroups. Why not much larger groups like SU(7), or for that matter, SP(38) or E7? We observe that fermions charged under large groups acquire much bigger dynamical masses, all things being equal at a high e.g. GUT scale, than ordinary quarks. Should such multicharged fermions exist, they are too heavy to be observed today and have either decayed early on (if they couple to the rest of the Standard Model) or become reliquial dark matter (if they don't). The result follows from strong antiscreening of the running coupling for those larger groups (with an appropriately small number of flavors) together with scaling properties of the Dyson-Schwinger equation for the fermion mass.
2311.00507
Maksym Ovchynnikov
Maksym Ovchynnikov, Jean-Loup Tastet, Oleksii Mikulenko, Kyrylo Bondarenko
Sensitivities to feebly interacting particles: public and unified calculations
EPS-HEP 2023 proceedings
PoS(EPS-HEP2023)449
10.22323/1.449.0456
EPS-HEP 2023 proceedings
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The increasing interest in Long-Lived Particles (LLPs) has led to numerous proposed experiments in order to search for them. However, the sensitivity estimates published by these experiments tend to rely on disparate assumptions. To ensure an accurate comparison of their potential to find LLPs, a unified estimation of their sensitivity is therefore required. In this contribution, we introduce \texttt{SensCalc}, a \texttt{Mathematica}-based code that uses a semi-analytic approach to calculate the event rate of GeV-scale LLPs, and we present several case studies.
[ { "created": "Wed, 1 Nov 2023 13:13:04 GMT", "version": "v1" } ]
2024-01-29
[ [ "Ovchynnikov", "Maksym", "" ], [ "Tastet", "Jean-Loup", "" ], [ "Mikulenko", "Oleksii", "" ], [ "Bondarenko", "Kyrylo", "" ] ]
The increasing interest in Long-Lived Particles (LLPs) has led to numerous proposed experiments in order to search for them. However, the sensitivity estimates published by these experiments tend to rely on disparate assumptions. To ensure an accurate comparison of their potential to find LLPs, a unified estimation of their sensitivity is therefore required. In this contribution, we introduce \texttt{SensCalc}, a \texttt{Mathematica}-based code that uses a semi-analytic approach to calculate the event rate of GeV-scale LLPs, and we present several case studies.
1601.05087
C\'edric Delaunay
C\'edric Delaunay, Roee Ozeri, Gilad Perez, Yotam Soreq
Probing Atomic Higgs-like Forces at the Precision Frontier
7 pages, added focus on light higgs-like mediators, electron density at the nucleus improved with effective quantum number, version accepted for publication in PRD
Phys. Rev. D 96, 093001 (2017)
10.1103/PhysRevD.96.093001
null
hep-ph physics.atom-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel approach to probe new fundamental interactions using isotope shift spectroscopy in atomic clock transitions. As concrete toy example we focus on the Higgs boson couplings to the building blocks of matter: the electron and the up and down quarks. We show that the attractive Higgs force between nuclei and their bound electrons, that is poorly constrained, might induce effects that are larger than the current experimental sensitivities. More generically, we discuss how new interactions between the electron and the neutrons, mediated via light new degrees of freedom, may lead to measurable non-linearities in a King plot comparison between isotope shifts of two different transitions. Given state-of-the-art accuracy in frequency comparison, isotope shifts have the potential of being measured with sub-Hz accuracy, thus potentially enabling the improvement of current limits on new fundamental interactions. Candidate atomic system for this measurement require two different clock transitions and four zero nuclear spin isotopes. We identify several systems that satisfy this requirement and also briefly discuss existing measurements. We consider the size of the effect related to the Higgs force and the requirements for it to produce an observable signal.
[ { "created": "Tue, 19 Jan 2016 21:00:01 GMT", "version": "v1" }, { "created": "Thu, 30 Jun 2016 19:17:03 GMT", "version": "v2" }, { "created": "Fri, 29 Sep 2017 20:52:06 GMT", "version": "v3" } ]
2017-11-15
[ [ "Delaunay", "Cédric", "" ], [ "Ozeri", "Roee", "" ], [ "Perez", "Gilad", "" ], [ "Soreq", "Yotam", "" ] ]
We propose a novel approach to probe new fundamental interactions using isotope shift spectroscopy in atomic clock transitions. As concrete toy example we focus on the Higgs boson couplings to the building blocks of matter: the electron and the up and down quarks. We show that the attractive Higgs force between nuclei and their bound electrons, that is poorly constrained, might induce effects that are larger than the current experimental sensitivities. More generically, we discuss how new interactions between the electron and the neutrons, mediated via light new degrees of freedom, may lead to measurable non-linearities in a King plot comparison between isotope shifts of two different transitions. Given state-of-the-art accuracy in frequency comparison, isotope shifts have the potential of being measured with sub-Hz accuracy, thus potentially enabling the improvement of current limits on new fundamental interactions. Candidate atomic system for this measurement require two different clock transitions and four zero nuclear spin isotopes. We identify several systems that satisfy this requirement and also briefly discuss existing measurements. We consider the size of the effect related to the Higgs force and the requirements for it to produce an observable signal.
2305.17827
Nityasa Mishra
Nityasa Mishra, Louis E. Strigari
Solar neutrinos with CE$\nu$NS and flavor-dependent radiative corrections
20 pages, 17 figures
Phys.Rev.D 108 (2023) 6, 063023
10.1103/PhysRevD.108.063023
MI-HET-812
hep-ph astro-ph.HE astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine solar neutrinos in dark matter detectors including the effects of flavor-dependent radiative corrections to the CE$\nu$NS cross section. Working within a full three-flavor framework, and including matter effects within the Sun and Earth, detectors with thresholds $\lesssim 1$ keV and exposures of $\sim 100$ ton-year could identify contributions to the cross section beyond tree level. The differences between the cross sections for the flavors, combined with the difference in fluxes, would provide a new and unique method to study the muon and tau components of the solar neutrino flux. Flavor-dependent corrections induce a small day-night asymmetry of $< |3 \times10^{-4}|$ in the event rate, which if ultimately accessible would provide a novel probe of flavor oscillations.
[ { "created": "Sun, 28 May 2023 23:37:34 GMT", "version": "v1" }, { "created": "Wed, 27 Sep 2023 01:03:48 GMT", "version": "v2" } ]
2023-09-28
[ [ "Mishra", "Nityasa", "" ], [ "Strigari", "Louis E.", "" ] ]
We examine solar neutrinos in dark matter detectors including the effects of flavor-dependent radiative corrections to the CE$\nu$NS cross section. Working within a full three-flavor framework, and including matter effects within the Sun and Earth, detectors with thresholds $\lesssim 1$ keV and exposures of $\sim 100$ ton-year could identify contributions to the cross section beyond tree level. The differences between the cross sections for the flavors, combined with the difference in fluxes, would provide a new and unique method to study the muon and tau components of the solar neutrino flux. Flavor-dependent corrections induce a small day-night asymmetry of $< |3 \times10^{-4}|$ in the event rate, which if ultimately accessible would provide a novel probe of flavor oscillations.
hep-ph/0008049
Andrea Romanino
Andre Lukas (Oxford U.), Pierre Ramond (Florida U.), Andrea Romanino and Graham G. Ross (Oxford U.)
Solar neutrino oscillation from large extra dimensions
15 pages, 2 figures
Phys.Lett. B495 (2000) 136-146
10.1016/S0370-2693(00)01206-5
OUTP-00-34P
hep-ph
null
A plausible explanation for the existence of additional light sterile neutrinos is that they correspond to modulini, fermionic partners of moduli, which propagate in new large dimensions. We discuss the phenomenological implications of such states and show that solar neutrino oscillation is well described by small angle MSW oscillation to the tower of Kaluza Klein states associated with the modulini. In the optimal case the recoil electron energy spectrum agrees precisely with the measured one, in contrast to the single sterile neutrino case which is disfavoured. We also consider how all oscillation phenomena can be explained in a model including bulk neutrino states. In particular, we show that a naturally maximal mixing for atmospheric neutrinos can be easily obtained.
[ { "created": "Sat, 5 Aug 2000 01:35:35 GMT", "version": "v1" }, { "created": "Mon, 30 Oct 2000 17:07:44 GMT", "version": "v2" } ]
2009-10-31
[ [ "Lukas", "Andre", "", "Oxford U." ], [ "Ramond", "Pierre", "", "Florida U." ], [ "Romanino", "Andrea", "", "Oxford U." ], [ "Ross", "Graham G.", "", "Oxford U." ] ]
A plausible explanation for the existence of additional light sterile neutrinos is that they correspond to modulini, fermionic partners of moduli, which propagate in new large dimensions. We discuss the phenomenological implications of such states and show that solar neutrino oscillation is well described by small angle MSW oscillation to the tower of Kaluza Klein states associated with the modulini. In the optimal case the recoil electron energy spectrum agrees precisely with the measured one, in contrast to the single sterile neutrino case which is disfavoured. We also consider how all oscillation phenomena can be explained in a model including bulk neutrino states. In particular, we show that a naturally maximal mixing for atmospheric neutrinos can be easily obtained.
1312.5571
Oscar St{\aa}l
R. Harlander, M. M\"uhlleitner, J. Rathsman, M. Spira, O. St{\aa}l
Interim recommendations for the evaluation of Higgs production cross sections and branching ratios at the LHC in the Two-Higgs-Doublet Model
30 pages, 1 figure. Several tables with numerical results for cross sections and branching ratios in reference scenarios
null
null
LHCHXSWG-2013-001, KA-TP-41-2013, LU TP 13-44, PSI-PR-13-17, WUB/13-19
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note we give interim recommendations on how to evaluate LHC cross sections for (neutral) Higgs production and Higgs branching ratios in the general (CP-conserving) Two-Higgs-Doublet Model (2HDM). The current status of available higher-order corrections to Higgs production and decay in this model is discussed, and the existing public codes implementing these calculations are described. Numerical results are presented for a set of reference scenarios, demonstrating the very good agreement between the results obtained using different programs.
[ { "created": "Thu, 19 Dec 2013 14:58:39 GMT", "version": "v1" }, { "created": "Tue, 28 Jan 2014 19:56:44 GMT", "version": "v2" } ]
2014-01-29
[ [ "Harlander", "R.", "" ], [ "Mühlleitner", "M.", "" ], [ "Rathsman", "J.", "" ], [ "Spira", "M.", "" ], [ "Stål", "O.", "" ] ]
In this note we give interim recommendations on how to evaluate LHC cross sections for (neutral) Higgs production and Higgs branching ratios in the general (CP-conserving) Two-Higgs-Doublet Model (2HDM). The current status of available higher-order corrections to Higgs production and decay in this model is discussed, and the existing public codes implementing these calculations are described. Numerical results are presented for a set of reference scenarios, demonstrating the very good agreement between the results obtained using different programs.
1712.00869
Nobuchika Okada
Tong Li, Nobuchika Okada, Qaisar Shafi
Scalar dark matter, Type II Seesaw and the DAMPE cosmic ray $e^+ + e^-$ excess
6 pages, 2 figures, to be published in PLB
null
10.1016/j.physletb.2018.02.006
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The DArk Matter Particle Explorer (DAMPE) has reported a measurement of the flux of high energy cosmic ray electrons plus positrons (CREs) in the energy range between $25$ GeV and $4.6$ TeV. With unprecedented high energy resolution, the DAMPE data exhibit an excess of the CREs flux at an energy of around $1.4$ TeV. In this letter, we discuss how the observed excess can be understood in a minimal framework where the Standard Model (SM) is supplemented by a stable SM singlet scalar as dark matter (DM) and type II seesaw for generating the neutrino mass matrix. In our framework, a pair of DM particles annihilates into a pair of the SM SU(2) triplet scalars ($\Delta$s) in type II seesaw, and the subsequent $\Delta$ decays create the primary source of the excessive CREs around $1.4$ TeV. The lepton flavor structure of the primary source of CREs has a direct relationship with the neutrino oscillation data. We find that the DM interpretation of the DAMPE excess determines the pattern of neutrino mass spectrum to be the inverted hierarchy type, taking into account the constraints from the Fermi-LAT observations of dwarf spheroidal galaxies.
[ { "created": "Mon, 4 Dec 2017 01:27:59 GMT", "version": "v1" }, { "created": "Mon, 5 Feb 2018 01:43:47 GMT", "version": "v2" } ]
2018-02-07
[ [ "Li", "Tong", "" ], [ "Okada", "Nobuchika", "" ], [ "Shafi", "Qaisar", "" ] ]
The DArk Matter Particle Explorer (DAMPE) has reported a measurement of the flux of high energy cosmic ray electrons plus positrons (CREs) in the energy range between $25$ GeV and $4.6$ TeV. With unprecedented high energy resolution, the DAMPE data exhibit an excess of the CREs flux at an energy of around $1.4$ TeV. In this letter, we discuss how the observed excess can be understood in a minimal framework where the Standard Model (SM) is supplemented by a stable SM singlet scalar as dark matter (DM) and type II seesaw for generating the neutrino mass matrix. In our framework, a pair of DM particles annihilates into a pair of the SM SU(2) triplet scalars ($\Delta$s) in type II seesaw, and the subsequent $\Delta$ decays create the primary source of the excessive CREs around $1.4$ TeV. The lepton flavor structure of the primary source of CREs has a direct relationship with the neutrino oscillation data. We find that the DM interpretation of the DAMPE excess determines the pattern of neutrino mass spectrum to be the inverted hierarchy type, taking into account the constraints from the Fermi-LAT observations of dwarf spheroidal galaxies.
hep-ph/0106056
Will Loinaz
Oleg Lebedev and Will Loinaz
Supersymmetry and Electroweak Leptonic Observables
26 pages, 12 figures. Minor corrections, references added, conclusions unchanged. To be published in PRD
Phys.Rev. D65 (2002) 033005
10.1103/PhysRevD.65.033005
SUSX-TH/01-025
hep-ph
null
We study vertex corrections to the leptonic electroweak observables in the general MSSM at tan(beta) < 35. In particular, we address the question of whether supersymmetry can be responsible for the observed 2 sigma deviation from the Standard Model prediction in the invisible width of the Z. We find that the presence of a light (around 100 GeV) chargino and sleptons hinted by the muon g-2 measurements makes the agreement with experiment slightly better and improves the electroweak fit.
[ { "created": "Tue, 5 Jun 2001 18:06:24 GMT", "version": "v1" }, { "created": "Wed, 24 Oct 2001 02:39:15 GMT", "version": "v2" } ]
2009-11-07
[ [ "Lebedev", "Oleg", "" ], [ "Loinaz", "Will", "" ] ]
We study vertex corrections to the leptonic electroweak observables in the general MSSM at tan(beta) < 35. In particular, we address the question of whether supersymmetry can be responsible for the observed 2 sigma deviation from the Standard Model prediction in the invisible width of the Z. We find that the presence of a light (around 100 GeV) chargino and sleptons hinted by the muon g-2 measurements makes the agreement with experiment slightly better and improves the electroweak fit.
1712.01136
C. Hanhart
C. Hanhart
Theory Concepts for Heavy Exotic Mesons
8 pages, 1 figure; Invited plenary talk presented at PANIC 2017,Beijing, China
null
10.1142/S2010194518600042
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Some of the currently most popular conjectures for the structure of the recently discovered heavy mesons that do not find a place in the quark model quarkonium spectrum are sketched. Furthermore, some observables are identified that should allow one to identify the most prominent components of individual states.
[ { "created": "Mon, 4 Dec 2017 15:05:51 GMT", "version": "v1" } ]
2018-05-23
[ [ "Hanhart", "C.", "" ] ]
Some of the currently most popular conjectures for the structure of the recently discovered heavy mesons that do not find a place in the quark model quarkonium spectrum are sketched. Furthermore, some observables are identified that should allow one to identify the most prominent components of individual states.
hep-ph/0112209
Servant
G. Servant
A Way to Reopen the Window for Electroweak Baryogenesis
19 pages, 3 figures; v2: minor changes, remark added at end of section 5 and in caption of figure 1; v3: references added, version to be published
JHEP 0201:044,2002
10.1088/1126-6708/2002/01/044
ANL-HEP-PR-01-120, EFI-01-55
hep-ph astro-ph hep-th
null
We reanalyse the sphaleron bound of electroweak baryogenesis when allowing deviations to the Friedmann equation. These modifications are well motivated in the context of brane cosmology where they appear without being in conflict with major experimental constraints on four-dimensional gravity. While suppressed at the time of nucleosynthesis, these corrections can dominate at the time of the electroweak phase transition and in certain cases provide the amount of expansion needed to freeze out the baryon asymmetry without requiring a strongly first order phase transition. The sphaleron bound is substantially weakened and can even disappear so that the constraints on the higgs and stop masses do not apply anymore. Such modification of cosmology at early times therefore reopens the parameter space allowing electroweak baryogenesis which had been reduced substantially given the new bound on the higgs mass imposed by LEP. In contrast with previous attempts to turn around the sphaleron bound using alternative cosmologies, we are still considering that the electroweak phase transition takes place in a radiation dominated universe. The universe is expanding fast because of the modification of the Friedmann equation itself without the need for a scalar field and therefore evading the problem of the decay of this scalar field after the completion of the phase transition and the risk that its release of entropy dilutes the baryon asymmetry produced at the transition.
[ { "created": "Fri, 14 Dec 2001 21:04:30 GMT", "version": "v1" }, { "created": "Thu, 10 Jan 2002 21:05:07 GMT", "version": "v2" }, { "created": "Tue, 5 Feb 2002 16:34:27 GMT", "version": "v3" } ]
2014-11-17
[ [ "Servant", "G.", "" ] ]
We reanalyse the sphaleron bound of electroweak baryogenesis when allowing deviations to the Friedmann equation. These modifications are well motivated in the context of brane cosmology where they appear without being in conflict with major experimental constraints on four-dimensional gravity. While suppressed at the time of nucleosynthesis, these corrections can dominate at the time of the electroweak phase transition and in certain cases provide the amount of expansion needed to freeze out the baryon asymmetry without requiring a strongly first order phase transition. The sphaleron bound is substantially weakened and can even disappear so that the constraints on the higgs and stop masses do not apply anymore. Such modification of cosmology at early times therefore reopens the parameter space allowing electroweak baryogenesis which had been reduced substantially given the new bound on the higgs mass imposed by LEP. In contrast with previous attempts to turn around the sphaleron bound using alternative cosmologies, we are still considering that the electroweak phase transition takes place in a radiation dominated universe. The universe is expanding fast because of the modification of the Friedmann equation itself without the need for a scalar field and therefore evading the problem of the decay of this scalar field after the completion of the phase transition and the risk that its release of entropy dilutes the baryon asymmetry produced at the transition.
hep-ph/9306303
null
Paolo Provero
Valley Singularities and Baryon Number Violation
6 pages, LaTex, TPI-MINN-93/32-T
Phys.Lett.B321:95-98,1994
10.1016/0370-2693(94)90332-8
null
hep-ph
null
We consider the valley--method computation of the inclusive cross section of baryon number violating processes in the Standard Model. We show that any physically correct model of the valley action should present a singularity in the saddle point valley parameters as functions of the energy of the process. This singularity prevents the saddle point configuration from collapsing into the perturbative vacuum.
[ { "created": "Wed, 23 Jun 1993 00:29:24 GMT", "version": "v1" } ]
2014-11-17
[ [ "Provero", "Paolo", "" ] ]
We consider the valley--method computation of the inclusive cross section of baryon number violating processes in the Standard Model. We show that any physically correct model of the valley action should present a singularity in the saddle point valley parameters as functions of the energy of the process. This singularity prevents the saddle point configuration from collapsing into the perturbative vacuum.
1709.01511
Emanuele Roberto Nocera
Emanuele R. Nocera, Huey-Wen Lin, Fred Olness, Kostas Orginos and Juan Rojo
The PDFLattice2017 workshop: a summary report
5 pages, 1 figure, contribution to the proceedings of the XXV Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2017)
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The workshop on Parton Distributions and Lattice Calculations in the LHC era (PDFLattice2017) was hosted at Balliol College, Oxford (UK), from 22$^{\rm nd}$ to 24$^{\rm th}$ March 2017. The workshop brought together the lattice-QCD and the global-fit physicists who devote their efforts to determine the parton distribution functions (PDFs) of the proton. The goals were to make the two communities more familiar between each other, review developments from both sides, and set precision targets for lattice calculations so that they can contribute, together with the forthcoming experimental input, to the next generation of PDF determinations. This contribution summarises the relevant outcome of the workshop, in anticipation of a thorough white paper.
[ { "created": "Tue, 5 Sep 2017 17:59:34 GMT", "version": "v1" }, { "created": "Mon, 11 Sep 2017 13:57:57 GMT", "version": "v2" } ]
2017-09-12
[ [ "Nocera", "Emanuele R.", "" ], [ "Lin", "Huey-Wen", "" ], [ "Olness", "Fred", "" ], [ "Orginos", "Kostas", "" ], [ "Rojo", "Juan", "" ] ]
The workshop on Parton Distributions and Lattice Calculations in the LHC era (PDFLattice2017) was hosted at Balliol College, Oxford (UK), from 22$^{\rm nd}$ to 24$^{\rm th}$ March 2017. The workshop brought together the lattice-QCD and the global-fit physicists who devote their efforts to determine the parton distribution functions (PDFs) of the proton. The goals were to make the two communities more familiar between each other, review developments from both sides, and set precision targets for lattice calculations so that they can contribute, together with the forthcoming experimental input, to the next generation of PDF determinations. This contribution summarises the relevant outcome of the workshop, in anticipation of a thorough white paper.
1905.01192
Michael Kachelrie{\ss}
M. Kachelriess, S. Ostapchenko and J. Tjemsland
Alternative coalescence model for deuteron, tritium, helium-3 and their antinuclei
19 pages, 7 pdf figures; v2: minor changes, added references, accepted version
J. Eur. Phys. J. A (2020) 56: 4
10.1140/epja/s10050-019-00007-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Antideuteron and antihelium nuclei have been proposed as a detection channel for dark matter annihilations and decays in the Milky Way, due to the low astrophysical background expected. To estimate both the signal for various dark matter models and the astrophysical background, one employs usually the coalescence model in a Monte Carlo framework. This allows one to treat the production of antinuclei on an event-by-event basis, taking thereby into account momentum correlations between the antinucleons involved in the process. This approach lacks however an underlying microscopic picture, and the numerical value of the coalescence parameter obtained from fits to different reactions varies considerably. Here we propose instead to combine event-by-event Monte Carlo simulations with a microscopic coalescence picture based on the Wigner function representations of the produced antinuclei states. This approach allows us to include in a semi-classical picture both the size of the formation region, which is process dependent, and momentum correlations. The model contains a single, universal parameter which is fixed by fitting the production spectra of antideuterons in proton-proton interactions, measured at the Large Hadron Collider. Using this value, the model describes well the production of various antinuclei both in electron-positron annihilation and in proton-proton collisions.
[ { "created": "Fri, 3 May 2019 14:09:22 GMT", "version": "v1" }, { "created": "Tue, 29 Oct 2019 07:46:17 GMT", "version": "v2" } ]
2020-01-15
[ [ "Kachelriess", "M.", "" ], [ "Ostapchenko", "S.", "" ], [ "Tjemsland", "J.", "" ] ]
Antideuteron and antihelium nuclei have been proposed as a detection channel for dark matter annihilations and decays in the Milky Way, due to the low astrophysical background expected. To estimate both the signal for various dark matter models and the astrophysical background, one employs usually the coalescence model in a Monte Carlo framework. This allows one to treat the production of antinuclei on an event-by-event basis, taking thereby into account momentum correlations between the antinucleons involved in the process. This approach lacks however an underlying microscopic picture, and the numerical value of the coalescence parameter obtained from fits to different reactions varies considerably. Here we propose instead to combine event-by-event Monte Carlo simulations with a microscopic coalescence picture based on the Wigner function representations of the produced antinuclei states. This approach allows us to include in a semi-classical picture both the size of the formation region, which is process dependent, and momentum correlations. The model contains a single, universal parameter which is fixed by fitting the production spectra of antideuterons in proton-proton interactions, measured at the Large Hadron Collider. Using this value, the model describes well the production of various antinuclei both in electron-positron annihilation and in proton-proton collisions.
2007.00005
Alberto Salvio
Anish Ghoshal and Alberto Salvio
Gravitational Waves from Fundamental Axion Dynamics
23 pages, 9 figures; accepted for publication in JHEP
JHEP 12 (2020) 049
10.1007/JHEP12(2020)049
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A totally asymptotically free QCD axion model, where all couplings flow to zero in the infinite energy limit, was recently formulated. A very interesting feature of this fundamental theory is the ability to predict some low-energy observables, like the masses of the extra fermions and scalars. Here we find and investigate a region of the parameter space where the Peccei-Quinn (PQ) symmetry is broken quantum mechanically through the Coleman-Weinberg mechanism. This results in an even more predictive framework: the axion sector features only two independent parameters (the PQ symmetry breaking scale and the QCD gauge coupling). In particular, we show that the PQ phase transition is strongly first order and can produce gravitational waves within the reach of future detectors. The predictivity of the model leads to a rigid dependence of the phase transition (like its duration and the nucleation temperature) and the gravitational wave spectrum on the PQ symmetry breaking scale and the QCD gauge coupling.
[ { "created": "Tue, 30 Jun 2020 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 1 Dec 2020 14:35:08 GMT", "version": "v2" } ]
2020-12-30
[ [ "Ghoshal", "Anish", "" ], [ "Salvio", "Alberto", "" ] ]
A totally asymptotically free QCD axion model, where all couplings flow to zero in the infinite energy limit, was recently formulated. A very interesting feature of this fundamental theory is the ability to predict some low-energy observables, like the masses of the extra fermions and scalars. Here we find and investigate a region of the parameter space where the Peccei-Quinn (PQ) symmetry is broken quantum mechanically through the Coleman-Weinberg mechanism. This results in an even more predictive framework: the axion sector features only two independent parameters (the PQ symmetry breaking scale and the QCD gauge coupling). In particular, we show that the PQ phase transition is strongly first order and can produce gravitational waves within the reach of future detectors. The predictivity of the model leads to a rigid dependence of the phase transition (like its duration and the nucleation temperature) and the gravitational wave spectrum on the PQ symmetry breaking scale and the QCD gauge coupling.
1408.4024
Kyoungchul Kong
Thomas Flacke, Kyoungchul Kong, Seong Chan Park
A Review on Non-Minimal Universal Extra Dimensions
14 pages, invited review on non-minimal universal extra dimensions to appear in Modern Physics Letters A
null
10.1142/S0217732315300037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on the current status of non-minimal universal extra dimension (UED) models. Our emphasis is on the possible extension of the minimal UED model by allowing bulk masses and boundary localized terms. We take into account the data from the Large Hadron Collider as well as direct and indirect searches of dark matter and electroweak precision measurements.
[ { "created": "Mon, 18 Aug 2014 14:43:14 GMT", "version": "v1" } ]
2015-06-22
[ [ "Flacke", "Thomas", "" ], [ "Kong", "Kyoungchul", "" ], [ "Park", "Seong Chan", "" ] ]
We report on the current status of non-minimal universal extra dimension (UED) models. Our emphasis is on the possible extension of the minimal UED model by allowing bulk masses and boundary localized terms. We take into account the data from the Large Hadron Collider as well as direct and indirect searches of dark matter and electroweak precision measurements.
1603.01769
Nathan Papapietro
Nobuchika Okada and Nathan Papapietro
R-parity Conserving Minimal SUSY $B-L$ Model
17 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a simple gauged U(1)$_{B-L}$ extension of the minimal supersymmetric Standard Model (MSSM), where R-parity is conserved as usual in the MSSM. The global $B-L$ (baryon number minus lepton number) symmetry in the MSSM is gauged and three MSSM gauge-singlet chiral multiplets with a unit $B-L$ charge are introduced, ensuring the model free from gauge and gravitational anomalies. We assign an odd R-parity for two of the new chiral multiplets and hence they are identified with the right-handed neutrino superfields, while an even R-parity is assigned to the other one ($\Phi$). The scalar component of $\Phi$ plays the role of a Higgs field to break the U(1)$_{B-L}$ symmetry through its negative mass squared, which is radiatively generated by the renormalization group running of soft supersymmetry (SUSY) breaking parameters from a high energy. This radiative U(1)$_{B-L}$ symmetry breaking leads to its breaking scale being at the TeV naturally. Because of our novel R-parity assignment, three light neutrinos are Dirac particles with one massless state. Since R-parity is conserved, the lightest neutralino is a prime candidate of the dark matter as usual. In our model, the lightest eigenstate of the mixture of the $B-L$ gaugino and the fermionic component of $\Phi$ appears as a new dark matter candidate. We investigate phenomenology of this dark matter particle. We also discuss collider phenomenology of our model. In particular, the $B-L$ gauge boson ($Z'$), once discovered at the Large Hadron Collider, can be a probe to determine the number of (right-handed) Dirac neutrinos with its invisible decay width, in sharp contrast with the conventional $B-L$ extension of the SM or MSSM where the right-handed neutrinos are heavy Majorana particles and decay to the SM leptons.
[ { "created": "Sun, 6 Mar 2016 00:00:50 GMT", "version": "v1" } ]
2016-03-08
[ [ "Okada", "Nobuchika", "" ], [ "Papapietro", "Nathan", "" ] ]
We propose a simple gauged U(1)$_{B-L}$ extension of the minimal supersymmetric Standard Model (MSSM), where R-parity is conserved as usual in the MSSM. The global $B-L$ (baryon number minus lepton number) symmetry in the MSSM is gauged and three MSSM gauge-singlet chiral multiplets with a unit $B-L$ charge are introduced, ensuring the model free from gauge and gravitational anomalies. We assign an odd R-parity for two of the new chiral multiplets and hence they are identified with the right-handed neutrino superfields, while an even R-parity is assigned to the other one ($\Phi$). The scalar component of $\Phi$ plays the role of a Higgs field to break the U(1)$_{B-L}$ symmetry through its negative mass squared, which is radiatively generated by the renormalization group running of soft supersymmetry (SUSY) breaking parameters from a high energy. This radiative U(1)$_{B-L}$ symmetry breaking leads to its breaking scale being at the TeV naturally. Because of our novel R-parity assignment, three light neutrinos are Dirac particles with one massless state. Since R-parity is conserved, the lightest neutralino is a prime candidate of the dark matter as usual. In our model, the lightest eigenstate of the mixture of the $B-L$ gaugino and the fermionic component of $\Phi$ appears as a new dark matter candidate. We investigate phenomenology of this dark matter particle. We also discuss collider phenomenology of our model. In particular, the $B-L$ gauge boson ($Z'$), once discovered at the Large Hadron Collider, can be a probe to determine the number of (right-handed) Dirac neutrinos with its invisible decay width, in sharp contrast with the conventional $B-L$ extension of the SM or MSSM where the right-handed neutrinos are heavy Majorana particles and decay to the SM leptons.
hep-ph/9604425
null
P.Colangelo, F.De Fazio
Role of Four-Quark Operators in the Inclusive $\Lambda_b$ Decays
LaTex, 14 pages, 3 uuencoded postscript figures
Phys.Lett.B387:371-378,1996
10.1016/0370-2693(96)01049-0
BARI-TH/96-230
hep-ph
null
We compute by QCD sum rules the matrix elements of the relevant four-quark operators appearing in the expression of the $\Lambda_b$ inclusive decay rates at the order $1/m_b^3$. The results suggest that $1/m_b^3$ corrections are not responsible of the observed difference between the lifetime of $\Lambda_b$ and $B_d$.
[ { "created": "Mon, 29 Apr 1996 13:57:57 GMT", "version": "v1" } ]
2011-01-27
[ [ "Colangelo", "P.", "" ], [ "De Fazio", "F.", "" ] ]
We compute by QCD sum rules the matrix elements of the relevant four-quark operators appearing in the expression of the $\Lambda_b$ inclusive decay rates at the order $1/m_b^3$. The results suggest that $1/m_b^3$ corrections are not responsible of the observed difference between the lifetime of $\Lambda_b$ and $B_d$.
1212.0166
Piotr Lebiedowicz
Piotr Lebiedowicz and Antoni Szczurek
Exclusive production of meson pairs and resonances in proton-proton collisions
4 pages, 3 figures, contribution to the Proceedings of "Diffraction2012", Puerto del Carmen, Lanzarote, Spain, Sept. 10-15th, 2012
AIP Conf.Proc. 1523 (2012) 132-136
10.1063/1.4802134
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report a study of the central exclusive production of $\pi^{+} \pi^{-}$ and $K^{+}K^{-}$ pairs in high energy hadron-hadron collisions. The amplitude is calculated in the Regge approach including both pomeron and secondary reggeon exchanges and absorption effects due to proton-proton interaction and $\pi\pi$ ($KK$) rescattering. We discuss a measurement of exclusive production of a scalar $\chi_{c0}$ meson via $\chi_{c0} \to \pi^{+} \pi^{-}$, $K^{+} K^{-}$ decay. We find that the relative contribution of resonance states and the $\pi\pi$ ($KK$) continuum strongly depend on the cut on pion (kaon) transverse momentum. We compare the results with the existing experimental data and present predictions for the RHIC, Tevatron and LHC colliders. We discuss also the $f_{2}(1270)$ meson production mediated by an effective tensor pomeron exchanges.
[ { "created": "Sat, 1 Dec 2012 22:38:30 GMT", "version": "v1" } ]
2013-05-29
[ [ "Lebiedowicz", "Piotr", "" ], [ "Szczurek", "Antoni", "" ] ]
We report a study of the central exclusive production of $\pi^{+} \pi^{-}$ and $K^{+}K^{-}$ pairs in high energy hadron-hadron collisions. The amplitude is calculated in the Regge approach including both pomeron and secondary reggeon exchanges and absorption effects due to proton-proton interaction and $\pi\pi$ ($KK$) rescattering. We discuss a measurement of exclusive production of a scalar $\chi_{c0}$ meson via $\chi_{c0} \to \pi^{+} \pi^{-}$, $K^{+} K^{-}$ decay. We find that the relative contribution of resonance states and the $\pi\pi$ ($KK$) continuum strongly depend on the cut on pion (kaon) transverse momentum. We compare the results with the existing experimental data and present predictions for the RHIC, Tevatron and LHC colliders. We discuss also the $f_{2}(1270)$ meson production mediated by an effective tensor pomeron exchanges.
1709.02866
Bin Wu
Bin Wu, Yuri V. Kovchegov
Time-Dependent Observables in Heavy Ion Collisions I: Setting up the Formalism
45 pages, 9 figures
null
10.1007/JHEP03(2018)158
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We adapt the Schwinger-Keldysh formalism to study heavy-ion collisions in perturbative QCD. Employing the formalism, we calculate the two-point gluon correlation function $G_{22}^{a\mu,b\nu}$ due to the lowest-order classical gluon fields in the McLerran-Venugopalan model of heavy ion collisions and observe an interesting transition from the classical fields to the quasi-particle picture at later times. Motivated by this observation, we push the formalism to higher orders in the coupling and calculate the contribution to $G_{22}^{a\mu,b\nu}$ coming from the diagrams representing a single rescattering between two of the produced gluons. We assume that the two gluons go on mass shell both before and after the rescattering. The result of our calculation depends on the ordering between the proper time of the rescattering $\tau_Z$ and the proper time $\tau$ when the gluon distribution is measured. For (i) $\tau_Z\gg 1/Q_s$ and $\tau-\tau_Z\gg 1/Q_s$ (with $Q_s$ the saturation scale) we obtain the same results as from the Boltzmann equation. For (ii) $\tau-\tau_Z\gg \tau_Z\gg 1/Q_s$ we end up with a result very different from kinetic theory and consistent with a picture of "free-streaming" particles. Due to the approximations made, our calculation is too coarse to indicate whether the ordering (i) or (ii) is the correct one: to resolve this controversy, we shall present a detailed diagrammatic calculation of the rescattering correction in the $\varphi^4$ theory in the second paper of this duplex.
[ { "created": "Fri, 8 Sep 2017 22:03:55 GMT", "version": "v1" } ]
2018-04-18
[ [ "Wu", "Bin", "" ], [ "Kovchegov", "Yuri V.", "" ] ]
We adapt the Schwinger-Keldysh formalism to study heavy-ion collisions in perturbative QCD. Employing the formalism, we calculate the two-point gluon correlation function $G_{22}^{a\mu,b\nu}$ due to the lowest-order classical gluon fields in the McLerran-Venugopalan model of heavy ion collisions and observe an interesting transition from the classical fields to the quasi-particle picture at later times. Motivated by this observation, we push the formalism to higher orders in the coupling and calculate the contribution to $G_{22}^{a\mu,b\nu}$ coming from the diagrams representing a single rescattering between two of the produced gluons. We assume that the two gluons go on mass shell both before and after the rescattering. The result of our calculation depends on the ordering between the proper time of the rescattering $\tau_Z$ and the proper time $\tau$ when the gluon distribution is measured. For (i) $\tau_Z\gg 1/Q_s$ and $\tau-\tau_Z\gg 1/Q_s$ (with $Q_s$ the saturation scale) we obtain the same results as from the Boltzmann equation. For (ii) $\tau-\tau_Z\gg \tau_Z\gg 1/Q_s$ we end up with a result very different from kinetic theory and consistent with a picture of "free-streaming" particles. Due to the approximations made, our calculation is too coarse to indicate whether the ordering (i) or (ii) is the correct one: to resolve this controversy, we shall present a detailed diagrammatic calculation of the rescattering correction in the $\varphi^4$ theory in the second paper of this duplex.
2404.17333
Gianluca Gregori
Jack W. D. Halliday, Giacomo Marocco, Konstantin A. Beyer, Charles Heaton, Motoaki Nakatsutsumi, Thomas R. Preston, Charles D. Arrowsmith, Carsten Baehtz, Sebastian Goede, Oliver Humphries, Alejandro Laso Garcia, Richard Plackett, Pontus Svensson, Georgios Vacalis, Justin Wark, Daniel Wood, Ulf Zastrau, Robert Bingham, Ian Shipsey, Subir Sarkar, Gianluca Gregori
New bounds on heavy axions with an X-ray free electron laser
7 pages, 6 figures
null
null
null
hep-ph hep-ex physics.atom-ph physics.ins-det
http://creativecommons.org/licenses/by/4.0/
We present new exclusion bounds obtained at the European X-ray Free Electron Laser facility (EuXFEL) on axion-like particles (ALPs) in the mass range 10^{-3} eV < m_a < 10^{4} eV. Our experiment exploits the Primakoff effect via which photons can, in the presence of a strong external electric field, decay into axions, which then convert back into photons after passing through an opaque wall. While similar searches have been performed previously at a 3^rd generation synchrotron [1], our work demonstrates improved sensitivity, exploiting the higher brightness of X-rays at EuXFEL.
[ { "created": "Fri, 26 Apr 2024 11:31:37 GMT", "version": "v1" }, { "created": "Fri, 10 May 2024 20:56:14 GMT", "version": "v2" }, { "created": "Sat, 6 Jul 2024 07:52:58 GMT", "version": "v3" } ]
2024-07-09
[ [ "Halliday", "Jack W. D.", "" ], [ "Marocco", "Giacomo", "" ], [ "Beyer", "Konstantin A.", "" ], [ "Heaton", "Charles", "" ], [ "Nakatsutsumi", "Motoaki", "" ], [ "Preston", "Thomas R.", "" ], [ "Arrowsmith", "C...
We present new exclusion bounds obtained at the European X-ray Free Electron Laser facility (EuXFEL) on axion-like particles (ALPs) in the mass range 10^{-3} eV < m_a < 10^{4} eV. Our experiment exploits the Primakoff effect via which photons can, in the presence of a strong external electric field, decay into axions, which then convert back into photons after passing through an opaque wall. While similar searches have been performed previously at a 3^rd generation synchrotron [1], our work demonstrates improved sensitivity, exploiting the higher brightness of X-rays at EuXFEL.
1301.4163
Leonard Fister
Leonard Fister and Jan M. Pawlowski
Confinement from Correlation Functions
23 pages, 28 figures
null
10.1103/PhysRevD.88.045010
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the Polyakov loop potential in Yang--Mills theory from the fully dressed primitively divergent correlation functions only. This is done in a variety of functional approaches ranging from functional renormalisation group equations over Dyson--Schwinger equations to two-particle irreducible functionals. We present a confinement criterion that links the infrared behaviour of propagators and vertices to the Polyakov loop expectation value. The present work extends the works of [1-3] to general functional methods and sharpens the confinement criterion presented there. The computations are based on the thermal correlation functions in the Landau gauge calculated in [4-6].
[ { "created": "Thu, 17 Jan 2013 17:22:11 GMT", "version": "v1" } ]
2015-06-12
[ [ "Fister", "Leonard", "" ], [ "Pawlowski", "Jan M.", "" ] ]
We compute the Polyakov loop potential in Yang--Mills theory from the fully dressed primitively divergent correlation functions only. This is done in a variety of functional approaches ranging from functional renormalisation group equations over Dyson--Schwinger equations to two-particle irreducible functionals. We present a confinement criterion that links the infrared behaviour of propagators and vertices to the Polyakov loop expectation value. The present work extends the works of [1-3] to general functional methods and sharpens the confinement criterion presented there. The computations are based on the thermal correlation functions in the Landau gauge calculated in [4-6].
2302.10212
Alberto Salvio
Alberto Salvio
Model-Independent Radiative Symmetry Breaking and Gravitational Waves
27 pages, 5 figures, published version
JCAP 04 (2023) 051
10.1088/1475-7516/2023/04/051
null
hep-ph astro-ph.CO gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
Models where symmetries are predominantly broken (and masses are then generated) through radiative corrections typically produce strong first-order phase transitions with a period of supercooling, when the temperature dropped by several orders of magnitude. Here it is shown that a model-independent description of these phenomena and the consequent production of potentially observable gravitational waves is possible in terms of few parameters (which are computable once the model is specified) if enough supercooling occurred. It is explicitly found how large the supercooling should be in terms of those parameters, in order for the model-independent description to be valid. It is also explained how to systematically improve the accuracy of such description by computing higher-order corrections in an expansion in powers of a small quantity, which is a function of the above-mentioned parameters. Furthermore, the corresponding gravitational wave spectrum is compared with the existing experimental results from the latest observing run of LIGO and VIRGO and the expected sensitivities of future gravitational wave experiments to find regions of the parameter space that are either ruled out or can lead to a future detection.
[ { "created": "Mon, 20 Feb 2023 19:00:03 GMT", "version": "v1" }, { "created": "Fri, 21 Apr 2023 05:12:55 GMT", "version": "v2" } ]
2023-04-24
[ [ "Salvio", "Alberto", "" ] ]
Models where symmetries are predominantly broken (and masses are then generated) through radiative corrections typically produce strong first-order phase transitions with a period of supercooling, when the temperature dropped by several orders of magnitude. Here it is shown that a model-independent description of these phenomena and the consequent production of potentially observable gravitational waves is possible in terms of few parameters (which are computable once the model is specified) if enough supercooling occurred. It is explicitly found how large the supercooling should be in terms of those parameters, in order for the model-independent description to be valid. It is also explained how to systematically improve the accuracy of such description by computing higher-order corrections in an expansion in powers of a small quantity, which is a function of the above-mentioned parameters. Furthermore, the corresponding gravitational wave spectrum is compared with the existing experimental results from the latest observing run of LIGO and VIRGO and the expected sensitivities of future gravitational wave experiments to find regions of the parameter space that are either ruled out or can lead to a future detection.
2101.10350
Masaki Yamada
Masaki Yamada and Tsutomu T. Yanagida
A natural and simple UV completion of the QCD axion model
6 pages, 1 figure
null
10.1016/j.physletb.2021.136267
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The novel PQ mechanism replaces the strong CP problem with some challenges in a model building. In particular, the challenges arise regarding i) the origin of an anomalous global symmetry called a PQ symmetry, ii) the scale of the PQ symmetry breaking, and iii) the quality of the PQ symmetry. In this letter, we provide a natural and simple UV completed model that addresses these challenges. Extra quarks and anti-quarks are separated by two branes in the Randall-Sundrum ${\bf R}^4 \times S^1 / {\bf Z}_2$ spacetime while a hidden SU($N_H$) gauge field condensates in the bulk. The brane separation is the origin of the PQ symmetry and its breaking scale is given by the dynamical scale of the SU($N_H$) gauge interaction. The (generalized) Casimir force of SU($N_H$) condensation stabilizes the 5th dimension, which guarantees the quality of the PQ symmetry.
[ { "created": "Mon, 25 Jan 2021 19:02:05 GMT", "version": "v1" } ]
2021-04-14
[ [ "Yamada", "Masaki", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
The novel PQ mechanism replaces the strong CP problem with some challenges in a model building. In particular, the challenges arise regarding i) the origin of an anomalous global symmetry called a PQ symmetry, ii) the scale of the PQ symmetry breaking, and iii) the quality of the PQ symmetry. In this letter, we provide a natural and simple UV completed model that addresses these challenges. Extra quarks and anti-quarks are separated by two branes in the Randall-Sundrum ${\bf R}^4 \times S^1 / {\bf Z}_2$ spacetime while a hidden SU($N_H$) gauge field condensates in the bulk. The brane separation is the origin of the PQ symmetry and its breaking scale is given by the dynamical scale of the SU($N_H$) gauge interaction. The (generalized) Casimir force of SU($N_H$) condensation stabilizes the 5th dimension, which guarantees the quality of the PQ symmetry.
hep-ph/9712493
Qiuyu Liu
Q.Y. Liu and A.Yu. Smirnov
Neutrino Mass Spectrum with $\nu_{\mu}$ $\to$ $\nu_s$ Oscillations of Atmospheric Neutrinos
Revtex, 30 pages, Figure 5 and discussion of supernova neutrinos in sect. 6 are corrected. One reference is added. This version will be published in Nucl. Phys. B
Nucl.Phys.B524:505-523,1998
10.1016/S0550-3213(98)00269-7
IC/97/211
hep-ph nucl-ex
null
We consider the ``standard'' spectrum of the active neutrinos (characterized by strong mass hierarchy and small mixing) with additional sterile neutrino, $\nu_s$. The sterile neutrino mixes strongly with the muon neutrino, so that $\nu_{\mu} \leftrightarrow \nu_s$ oscillations solve the atmospheric neutrino problem. We show that the parametric enhancement of the $\nu_{\mu} \leftrightarrow \nu_s$ oscillations occurs for the high energy atmospheric neutrinos which cross the core of the Earth. This can be relevant for the anomaly observed by the MACRO experiment. Solar neutrinos are converted both to $\nu_{\mu}$ and $\nu_s$. The heaviest neutrino ($\approx \nu_{\tau}$) may compose the hot dark matter of the Universe. Phenomenology of this scenario is elaborated and crucial experimental signatures are identified. We also discuss properties of the underlying neutrino mass matrix.
[ { "created": "Mon, 22 Dec 1997 21:07:28 GMT", "version": "v1" }, { "created": "Fri, 10 Apr 1998 14:03:20 GMT", "version": "v2" }, { "created": "Mon, 4 May 1998 19:42:36 GMT", "version": "v3" } ]
2011-07-19
[ [ "Liu", "Q. Y.", "" ], [ "Smirnov", "A. Yu.", "" ] ]
We consider the ``standard'' spectrum of the active neutrinos (characterized by strong mass hierarchy and small mixing) with additional sterile neutrino, $\nu_s$. The sterile neutrino mixes strongly with the muon neutrino, so that $\nu_{\mu} \leftrightarrow \nu_s$ oscillations solve the atmospheric neutrino problem. We show that the parametric enhancement of the $\nu_{\mu} \leftrightarrow \nu_s$ oscillations occurs for the high energy atmospheric neutrinos which cross the core of the Earth. This can be relevant for the anomaly observed by the MACRO experiment. Solar neutrinos are converted both to $\nu_{\mu}$ and $\nu_s$. The heaviest neutrino ($\approx \nu_{\tau}$) may compose the hot dark matter of the Universe. Phenomenology of this scenario is elaborated and crucial experimental signatures are identified. We also discuss properties of the underlying neutrino mass matrix.
hep-ph/9903269
Brau Fabian
F. Brau (Univ. of Mons-Hainaut)
Analytical solution of the relativistic Coulomb problem with a hard core interaction for a one-dimensional spinless Salpeter equation
10 pages, no figures, Revtex 3.0
J.Math.Phys. 40 (1999) 1119-1126
10.1063/1.532791
UMH-99-02-28
hep-ph
null
In this paper, we construct an analytical solution of the one-dimensional spinless Salpeter equation with a Coulomb potential supplemented by a hard core interaction, which keeps the particle in the x positive region.
[ { "created": "Fri, 5 Mar 1999 14:10:30 GMT", "version": "v1" } ]
2009-10-31
[ [ "Brau", "F.", "", "Univ. of Mons-Hainaut" ] ]
In this paper, we construct an analytical solution of the one-dimensional spinless Salpeter equation with a Coulomb potential supplemented by a hard core interaction, which keeps the particle in the x positive region.
2210.13120
Bo-Qiang Ma
Guangshuai Zhang, Bo-Qiang Ma
Axion-Photon Conversion of LHAASO Multi-TeV and PeV Photons
5 latex pages, 1 figure, final version for journal publication
Chinese Phys. Lett. 40 (2023) 011401
10.1088/0256-307X/40/1/011401
null
hep-ph astro-ph.HE gr-qc
http://creativecommons.org/licenses/by/4.0/
The Large High Altitude Air Shower Observatory (LHAASO) has reported the detection of a large number of multi-TeV-scale photon events including also several PeV-scale gamma-ray-photon events with energy as high as 1.4 PeV. The possibility that some of these events may have extragalactic origins is not yet excluded. Here we propose a mechanism for the traveling of very-high-energy (VHE) and ultra-high-energy (UHE) photons based upon the axion-photon conversion scenario, which allows extragalactic above-threshold photons to be detected by observers on the Earth. We show that the axion-photon conversation can serve as an alternative mechanism, besides the threshold anomaly due to Lorentz invariance violation, for the very-high-energy features of the newly observed gamma ray burst GRB 221009A.
[ { "created": "Mon, 24 Oct 2022 11:11:11 GMT", "version": "v1" }, { "created": "Mon, 28 Nov 2022 17:00:45 GMT", "version": "v2" }, { "created": "Thu, 8 Dec 2022 08:48:55 GMT", "version": "v3" }, { "created": "Thu, 15 Dec 2022 08:07:13 GMT", "version": "v4" }, { "cr...
2023-01-09
[ [ "Zhang", "Guangshuai", "" ], [ "Ma", "Bo-Qiang", "" ] ]
The Large High Altitude Air Shower Observatory (LHAASO) has reported the detection of a large number of multi-TeV-scale photon events including also several PeV-scale gamma-ray-photon events with energy as high as 1.4 PeV. The possibility that some of these events may have extragalactic origins is not yet excluded. Here we propose a mechanism for the traveling of very-high-energy (VHE) and ultra-high-energy (UHE) photons based upon the axion-photon conversion scenario, which allows extragalactic above-threshold photons to be detected by observers on the Earth. We show that the axion-photon conversation can serve as an alternative mechanism, besides the threshold anomaly due to Lorentz invariance violation, for the very-high-energy features of the newly observed gamma ray burst GRB 221009A.
0709.2175
Edward Shuryak
Edward Shuryak
Electric-Magnetic Struggle in QGP, Deconfinement and Baryons
written version of invited talk at ``Critical Point and Onset of Deconfinement", 4th International Workshop, July 9-13 2007, GSI Darmstadt,Germany
PoSCPOD07:016,2007
null
null
hep-ph
null
We argue that quite unusual properties of Quark-Gluon Plasma in the RHIC temperature domain $T=(1-2)T_c$ are consequences of the approximate equilibrium between electric and magnetic sectors reached above the deconfinement temperature. Already classical study of few body motion in a electric-magnetic plasma shows abnormally large scattering rate due to the so called ``magnetic bottle'' effect. Molecular dynamics simulation have found that equal mixture of electric and magnetic quasiparticles do produce plasmas of small viscosity and even smaller diffusion rate, comparable to what is needed to explain RHIC data and also to what follows from AdS/CFT. As a separate issue, we point out that right above $T_c$ there should be surviving s-wave baryons made of quarks ($N,\Delta$), as well as adjoint objects, 3-gluon and 3-monopole chains (the latter being nothing else but ``calorons'' or finite-T instantons).
[ { "created": "Thu, 13 Sep 2007 21:33:49 GMT", "version": "v1" } ]
2009-04-14
[ [ "Shuryak", "Edward", "" ] ]
We argue that quite unusual properties of Quark-Gluon Plasma in the RHIC temperature domain $T=(1-2)T_c$ are consequences of the approximate equilibrium between electric and magnetic sectors reached above the deconfinement temperature. Already classical study of few body motion in a electric-magnetic plasma shows abnormally large scattering rate due to the so called ``magnetic bottle'' effect. Molecular dynamics simulation have found that equal mixture of electric and magnetic quasiparticles do produce plasmas of small viscosity and even smaller diffusion rate, comparable to what is needed to explain RHIC data and also to what follows from AdS/CFT. As a separate issue, we point out that right above $T_c$ there should be surviving s-wave baryons made of quarks ($N,\Delta$), as well as adjoint objects, 3-gluon and 3-monopole chains (the latter being nothing else but ``calorons'' or finite-T instantons).
1302.4852
Giancarlo D'Ambrosio
Giancarlo D'Ambrosio
Rare Kaon decays
Proceedings of CKM 2012, the 7th International Workshop on the CKM Unitarity Triangle, University of Cincinnati, USA, 28 September - 2 October 2012
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Rare Kaon decays and CP violation are important tools to test the Standard Model and its extensions. We describe kaon physics observables testing CP violation and more generally short distance physics. Channels under consideration will be K -> pi nu nubar, K -> pi l+ l-, K+- > pi 3 pi, K+- -> pi+- pi gamma, KS -> mu mu and K+- -> pi+- pi0 e+ e-
[ { "created": "Wed, 20 Feb 2013 09:48:41 GMT", "version": "v1" } ]
2013-02-21
[ [ "D'Ambrosio", "Giancarlo", "" ] ]
Rare Kaon decays and CP violation are important tools to test the Standard Model and its extensions. We describe kaon physics observables testing CP violation and more generally short distance physics. Channels under consideration will be K -> pi nu nubar, K -> pi l+ l-, K+- > pi 3 pi, K+- -> pi+- pi gamma, KS -> mu mu and K+- -> pi+- pi0 e+ e-
1202.4769
Benjamin Fuks
Benjamin Fuks
Beyond the Minimal Supersymmetric Standard Model: from theory to phenomenology
39 pages, 5 figures, 7 tables; to appear in Mod. Phys. Lett. A
Int.J.Mod.Phys. A27 (2012) 1230007
10.1142/S0217751X12300074
IPHC-PHENO-12-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Thanks to the latest development in the field of Monte Carlo event generators and satellite programs allowing for a straightforward implementation of any beyond the Standard Model theory in those tools, studying the property of any softly-broken supersymmetric theory is become an easy task. We illustrate this statement in the context of two non-minimal supersymmetric theories, namely the Minimal Supersymmetric Standard Model with R-parity violation and the Minimal R-symmetric Supersymmetric Standard Model and choose to probe interaction vertices involving a non-standard color structure and the sector of the top quark. We show how to efficiently implement these theories in the Mathematica package FeynRules and use its interfaces to Monte Carlo tools for phenomenological studies. For the latter, we employ the latest version of the MadGraph program.
[ { "created": "Tue, 21 Feb 2012 21:10:50 GMT", "version": "v1" } ]
2012-04-03
[ [ "Fuks", "Benjamin", "" ] ]
Thanks to the latest development in the field of Monte Carlo event generators and satellite programs allowing for a straightforward implementation of any beyond the Standard Model theory in those tools, studying the property of any softly-broken supersymmetric theory is become an easy task. We illustrate this statement in the context of two non-minimal supersymmetric theories, namely the Minimal Supersymmetric Standard Model with R-parity violation and the Minimal R-symmetric Supersymmetric Standard Model and choose to probe interaction vertices involving a non-standard color structure and the sector of the top quark. We show how to efficiently implement these theories in the Mathematica package FeynRules and use its interfaces to Monte Carlo tools for phenomenological studies. For the latter, we employ the latest version of the MadGraph program.
2003.08772
Yu Hamada
Minoru Eto, Yu Hamada, Masafumi Kurachi and Muneto Nitta
Dynamics of Nambu monopole in two Higgs doublet models -- Cosmological Monopole Collider --
38 pages, 7 figures. v2: minor revisions, new references added
null
10.1007/JHEP07(2020)004
YGHP-20-02, KUNS-2807
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the dynamics of the Nambu monopole in two Higgs doublet models, which is a magnetic monopole attached by two topological $Z$ strings ($Z$ flux tubes) from two opposite sides. The monopole is a topologically stable solution of the equation of motions when the Higgs potential has global $U(1)$ and $\mathbb{Z}_2$ symmetries. In this paper, we consider more general cases without the $\mathbb{Z}_2$ symmetry, and find that it is no longer a static solution but moves along the $Z$ string being pulled by the heavier string. After analytically constructing an asymptotic form of the monopole, we confirm such a motion using the numerical relaxation method. In addition, we analyze the real time dynamics of the monopole based on a point-like approximation. Consequently, if there were long string networks with the monopoles in the early universe, the monopole accelerates nearly to the speed of light emitting electromagnetic radiations as a synchrotron accelerator, and collides to an anti-monopole on the string. This collision event, which we call the cosmological monopole collider, can produce much heavier particles than those we can see today, e.g., at the Large Hadron Collider.
[ { "created": "Thu, 19 Mar 2020 13:25:42 GMT", "version": "v1" }, { "created": "Tue, 30 Jun 2020 12:54:19 GMT", "version": "v2" } ]
2020-07-15
[ [ "Eto", "Minoru", "" ], [ "Hamada", "Yu", "" ], [ "Kurachi", "Masafumi", "" ], [ "Nitta", "Muneto", "" ] ]
We study the dynamics of the Nambu monopole in two Higgs doublet models, which is a magnetic monopole attached by two topological $Z$ strings ($Z$ flux tubes) from two opposite sides. The monopole is a topologically stable solution of the equation of motions when the Higgs potential has global $U(1)$ and $\mathbb{Z}_2$ symmetries. In this paper, we consider more general cases without the $\mathbb{Z}_2$ symmetry, and find that it is no longer a static solution but moves along the $Z$ string being pulled by the heavier string. After analytically constructing an asymptotic form of the monopole, we confirm such a motion using the numerical relaxation method. In addition, we analyze the real time dynamics of the monopole based on a point-like approximation. Consequently, if there were long string networks with the monopoles in the early universe, the monopole accelerates nearly to the speed of light emitting electromagnetic radiations as a synchrotron accelerator, and collides to an anti-monopole on the string. This collision event, which we call the cosmological monopole collider, can produce much heavier particles than those we can see today, e.g., at the Large Hadron Collider.
0905.0951
Balasubramanian Ananthanarayan
Gauhar Abbas, B. Ananthanarayan
Improved bounds on the radius and curvature of the K pi scalar form factor and implications to low-energy theorems
4 pages using EPJ style files, accepted for publication in European Physical Journal A
Eur.Phys.J.A41:7-11,2009
10.1140/epja/i2009-10801-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain stringent bounds in the < r^2 >_S^{K pi}-c plane where these are the scalar radius and the curvature parameters of the scalar pi K form factor respectively using analyticity and dispersion relation constraints, the knowledge of the form factor from the well-known Callan-Treiman point m_K^2-m_pi^2, as well as at m_pi^2-m_K^2 which we call the second Callan-Treiman point. The central values of these parameters from a recent determination are accomodated in the allowed region provided the higher loop corrections to the value of the form factor at the second Callan-Treiman point reduce the one-loop result by about 3% with F_K/F_pi=1.21. Such a variation in magnitude at the second Callan-Treiman point yields 0.12 fm^2 \lesssim < r^2>_S^{K pi} \lesssim 0.21 fm^2 and 0.56 GeV^{-4} \lesssim c \lesssim 1.47 GeV^{-4} and a strong correlation between them. A smaller value of F_K/F_pi shifts both bounds to lower values.
[ { "created": "Thu, 7 May 2009 04:47:44 GMT", "version": "v1" } ]
2009-07-22
[ [ "Abbas", "Gauhar", "" ], [ "Ananthanarayan", "B.", "" ] ]
We obtain stringent bounds in the < r^2 >_S^{K pi}-c plane where these are the scalar radius and the curvature parameters of the scalar pi K form factor respectively using analyticity and dispersion relation constraints, the knowledge of the form factor from the well-known Callan-Treiman point m_K^2-m_pi^2, as well as at m_pi^2-m_K^2 which we call the second Callan-Treiman point. The central values of these parameters from a recent determination are accomodated in the allowed region provided the higher loop corrections to the value of the form factor at the second Callan-Treiman point reduce the one-loop result by about 3% with F_K/F_pi=1.21. Such a variation in magnitude at the second Callan-Treiman point yields 0.12 fm^2 \lesssim < r^2>_S^{K pi} \lesssim 0.21 fm^2 and 0.56 GeV^{-4} \lesssim c \lesssim 1.47 GeV^{-4} and a strong correlation between them. A smaller value of F_K/F_pi shifts both bounds to lower values.
1801.09115
Seyed Yaser Ayazi
S. Peyman Zakeri, S. Mohammad Moosavi Nejad, Mohammadreza Zakeri and S. Yaser Ayazi
A Minimal Model For Two-Component FIMP Dark Matter: A Basic Search
30 pages, 4 igures
Chinese Physics C,Vol. 42, No. 7 (2018) 073101
10.1088/1674-1137/42/7/073101
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the multi-component configurations of dark matter phenomenology, we propose a minimal two-component configuration which is an extension of the Standard Model with only three new fields; one scalar and one fermion interact with the thermal soup through Higgs portal, mediated by the other scalar in such a way that the stabilities of dark matter candidates are made simultaneously by an explicit $Z_2$ symmetry. Against the most common freeze-out framework, we look for dark matter particle signatures in the freeze-in scenario by evaluating the relic density and detection signals. A simple distinguishing feature of the model is the lack of dark matter conversion, so the dark matter components act individually and the model can be adapted entirely to both singlet scalar and singlet fermionic models, separately. We find dark matter self-interaction as the most promising approach to probe such feeble models. Although the scalar component satisfies this constraint, the fermionic one refuses it even in the resonant region.
[ { "created": "Sat, 27 Jan 2018 17:43:27 GMT", "version": "v1" }, { "created": "Sat, 2 Jun 2018 13:05:02 GMT", "version": "v2" } ]
2018-06-05
[ [ "Zakeri", "S. Peyman", "" ], [ "Nejad", "S. Mohammad Moosavi", "" ], [ "Zakeri", "Mohammadreza", "" ], [ "Ayazi", "S. Yaser", "" ] ]
In the multi-component configurations of dark matter phenomenology, we propose a minimal two-component configuration which is an extension of the Standard Model with only three new fields; one scalar and one fermion interact with the thermal soup through Higgs portal, mediated by the other scalar in such a way that the stabilities of dark matter candidates are made simultaneously by an explicit $Z_2$ symmetry. Against the most common freeze-out framework, we look for dark matter particle signatures in the freeze-in scenario by evaluating the relic density and detection signals. A simple distinguishing feature of the model is the lack of dark matter conversion, so the dark matter components act individually and the model can be adapted entirely to both singlet scalar and singlet fermionic models, separately. We find dark matter self-interaction as the most promising approach to probe such feeble models. Although the scalar component satisfies this constraint, the fermionic one refuses it even in the resonant region.
0912.2663
Johann Haidenbauer
J. Haidenbauer, G. Krein
The reaction ppbar -> Lambda_c-Lambda_cbar close to threshold
12 pages, 4 figures
Phys.Lett.B687:314-319,2010
10.1016/j.physletb.2010.03.065
FZJ-IKP-TH-2009-38
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Predictions for the charm-production reaction antiproton-proton -> antiLambda_c-Lambda_c for energies near the threshold are presented. The calculations are performed in a meson-exchange framework in close analogy to our earlier study on antiproton-proton -> antiLambda-Lambda by connecting the two processes via SU(4) symmetry. The obtained antiLambda_c-Lambda_c production cross sections are in the order of 1 to 7 \mub, i.e. a factor of around 10 smaller than the corresponding cross sections for antiLambda-Lambda. However, they are 100 to 1000 times larger than predictions of other model calculations in the literature.
[ { "created": "Mon, 14 Dec 2009 15:23:59 GMT", "version": "v1" } ]
2010-04-30
[ [ "Haidenbauer", "J.", "" ], [ "Krein", "G.", "" ] ]
Predictions for the charm-production reaction antiproton-proton -> antiLambda_c-Lambda_c for energies near the threshold are presented. The calculations are performed in a meson-exchange framework in close analogy to our earlier study on antiproton-proton -> antiLambda-Lambda by connecting the two processes via SU(4) symmetry. The obtained antiLambda_c-Lambda_c production cross sections are in the order of 1 to 7 \mub, i.e. a factor of around 10 smaller than the corresponding cross sections for antiLambda-Lambda. However, they are 100 to 1000 times larger than predictions of other model calculations in the literature.
1809.09610
Arman Esmaili
Arman Esmaili and Kohta Murase
Constraining high-energy neutrinos from choked-jet supernovae with IceCube high-energy starting events
18 pages, 7 figures; v2: a few clarifications and references added, matches the version published in JCAP
JCAP 12 (2018) 008
10.1088/1475-7516/2018/12/008
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Different types of core-collapse supernovae (SNe) have been considered as candidate sources of high-energy cosmic neutrinos. Stripped-envelope SNe, including energetic events like hypernovae and super-luminous SNe, are of particular interest. They may harbor relativistic jets, which are capable of explaining the diversity among gamma-ray bursts (GRBs), low-luminosity GRBs, ultra-long GRBs, and broadline Type Ib/c SNe. Using the six-year IceCube data on high-energy starting events (HESEs), we perform an unbinned maximum likelihood analysis to search for spatial and temporal coincidences with 222 samples of SNe Ib/c. We find that the present data are consistent with the background only hypothesis, by which we place new upper constraints on the isotropic-equivalent energy of cosmic rays, ${\mathcal E}_{\rm cr}\lesssim{10}^{52}~{\rm erg}$, in the limit that all SNe are accompanied by on-axis jets. Our results demonstrate that not only upgoing muon neutrinos but also HESE data enable us to constrain the potential contribution of these SNe to the diffuse neutrino flux observed in IceCube. We also discuss implications for the next-generation neutrino detectors such as IceCube-Gen2.
[ { "created": "Tue, 25 Sep 2018 17:43:47 GMT", "version": "v1" }, { "created": "Sun, 9 Dec 2018 16:14:25 GMT", "version": "v2" } ]
2018-12-11
[ [ "Esmaili", "Arman", "" ], [ "Murase", "Kohta", "" ] ]
Different types of core-collapse supernovae (SNe) have been considered as candidate sources of high-energy cosmic neutrinos. Stripped-envelope SNe, including energetic events like hypernovae and super-luminous SNe, are of particular interest. They may harbor relativistic jets, which are capable of explaining the diversity among gamma-ray bursts (GRBs), low-luminosity GRBs, ultra-long GRBs, and broadline Type Ib/c SNe. Using the six-year IceCube data on high-energy starting events (HESEs), we perform an unbinned maximum likelihood analysis to search for spatial and temporal coincidences with 222 samples of SNe Ib/c. We find that the present data are consistent with the background only hypothesis, by which we place new upper constraints on the isotropic-equivalent energy of cosmic rays, ${\mathcal E}_{\rm cr}\lesssim{10}^{52}~{\rm erg}$, in the limit that all SNe are accompanied by on-axis jets. Our results demonstrate that not only upgoing muon neutrinos but also HESE data enable us to constrain the potential contribution of these SNe to the diffuse neutrino flux observed in IceCube. We also discuss implications for the next-generation neutrino detectors such as IceCube-Gen2.
1803.09176
Lahouari Semlala
Bouzid Boussaha, Farida Iddir, Lahouari Semlala
Predictions for the isolated diphoton production through NNLO in QCD and comparison to the 8 TeV ATLAS data
13 pages, 4 figures, 2 tables
Advances in High Energy Physics (2018) Article ID 4174602
10.1155/2018/4174602
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present cross section predictions for the isolated diphoton production in next-to-next-to-leading order (NNLO) QCD using the computational framework MATRIX. Both the integrated and the differential fiducial cross sections are calculated. We found that the arbitrary setup of the isolation procedure introduces uncertainties with a size comparable to the estimation of the theoretical uncertainties obtained with the customary variation of the factorization and renormalization scales. This fact is taken into account in the final result.
[ { "created": "Sat, 24 Mar 2018 22:58:00 GMT", "version": "v1" }, { "created": "Mon, 18 Jun 2018 06:52:09 GMT", "version": "v2" }, { "created": "Fri, 6 Mar 2020 17:54:29 GMT", "version": "v3" } ]
2020-03-09
[ [ "Boussaha", "Bouzid", "" ], [ "Iddir", "Farida", "" ], [ "Semlala", "Lahouari", "" ] ]
We present cross section predictions for the isolated diphoton production in next-to-next-to-leading order (NNLO) QCD using the computational framework MATRIX. Both the integrated and the differential fiducial cross sections are calculated. We found that the arbitrary setup of the isolation procedure introduces uncertainties with a size comparable to the estimation of the theoretical uncertainties obtained with the customary variation of the factorization and renormalization scales. This fact is taken into account in the final result.
2101.04733
M.I. Vyazovsky
M.A. Braun, E.M. Kuzminskii and M.I. Vyazovsky (Saint-Petersburg State University, Russia)
Local one-dimensional reggeon model of the interaction of pomerons and odderons
19 pages, 11 figures; submitted to Eur.Phys.Jour. C
null
10.1140/epjc/s10052-021-09467-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose the one-dimensional reggeon theory describing local pomerons and odderons. It generalizes the well-known one-dimensional theory of pomerons (the Gribov model) and includes only triple interaction vertices. The proposed theory is studied by numerical methods: the one-particle pomeron and odderon propagators and the pA amplitude are found as functions of rapidity by integrating the evolution equation.
[ { "created": "Tue, 12 Jan 2021 20:11:19 GMT", "version": "v1" }, { "created": "Fri, 5 Mar 2021 16:30:39 GMT", "version": "v2" }, { "created": "Mon, 3 May 2021 15:01:26 GMT", "version": "v3" }, { "created": "Fri, 9 Jul 2021 19:01:08 GMT", "version": "v4" } ]
2021-08-18
[ [ "Braun", "M. A.", "", "Saint-Petersburg State\n University, Russia" ], [ "Kuzminskii", "E. M.", "", "Saint-Petersburg State\n University, Russia" ], [ "Vyazovsky", "M. I.", "", "Saint-Petersburg State\n University, Russia" ] ]
We propose the one-dimensional reggeon theory describing local pomerons and odderons. It generalizes the well-known one-dimensional theory of pomerons (the Gribov model) and includes only triple interaction vertices. The proposed theory is studied by numerical methods: the one-particle pomeron and odderon propagators and the pA amplitude are found as functions of rapidity by integrating the evolution equation.
hep-ph/9203226
Shigemot
M. Kenmoku, E. Kitajima, Y. Okamoto and K. Shigemoto
Rotation Curves of Spiral Galaxies and Large Scale Structure of Universe under Generalized Einstein Action
16 pages
Int. J. Mod. Phys. D2 (1993) 123-134
10.1142/S0218271893000118
null
hep-ph
null
We consider an addition of the term which is a square of the scalar curvature to the Einstein-Hilbert action. Under this generalized action, we attempt to explain i) the flat rotation curves observed in spiral galaxies, which is usually attributed to the existence of dark matter, and ii) the contradicting observations of uniform cosmic microwave background and non-uniform galaxy distributions against redshift. For the former, we attain the flatness of velocities, although the magnitudes remain about half of the observations. For the latter, we obtain a solution with oscillating Hubble parameter under uniform mass distributions. This solution leads to several peaks of galaxy number counts as a function of redshift with the first peak corresponding to the Great Wall.
[ { "created": "Tue, 31 Mar 1992 11:53:46 GMT", "version": "v1" }, { "created": "Mon, 6 Apr 1992 09:01:32 GMT", "version": "v2" } ]
2009-10-22
[ [ "Kenmoku", "M.", "" ], [ "Kitajima", "E.", "" ], [ "Okamoto", "Y.", "" ], [ "Shigemoto", "K.", "" ] ]
We consider an addition of the term which is a square of the scalar curvature to the Einstein-Hilbert action. Under this generalized action, we attempt to explain i) the flat rotation curves observed in spiral galaxies, which is usually attributed to the existence of dark matter, and ii) the contradicting observations of uniform cosmic microwave background and non-uniform galaxy distributions against redshift. For the former, we attain the flatness of velocities, although the magnitudes remain about half of the observations. For the latter, we obtain a solution with oscillating Hubble parameter under uniform mass distributions. This solution leads to several peaks of galaxy number counts as a function of redshift with the first peak corresponding to the Great Wall.
1009.3117
Oscar Cata
Oscar Cata (IFIC & Universitat de Valencia)
Pad\'e approximants and the prediction of non-perturbative parameters in particle physics
Based on talk given at the conference "Approximation and extrapolation of convergent and divergent sequences and series", Luminy, September-October 2009. To be published in Applied Numerical Mathematics
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Commonly used techniques to study non-perturbative aspects of the strong interactions have a deep connection with rational approximants, and in particular with Pad\'e approximants to meromorphic functions. However, only recently this connection has been acknowledged and efforts at fully exploiting it are only starting. In this article I will briefly review the most prominent techniques used in non-perturbative strong interactions with special emphasis on its relation with Pad\'e approximants. I will then concentrate on a set of open problems outside the scope of these conventional techniques where Pad\'e approximants might be extremely useful.
[ { "created": "Thu, 16 Sep 2010 08:43:01 GMT", "version": "v1" } ]
2010-09-17
[ [ "Cata", "Oscar", "", "IFIC & Universitat de Valencia" ] ]
Commonly used techniques to study non-perturbative aspects of the strong interactions have a deep connection with rational approximants, and in particular with Pad\'e approximants to meromorphic functions. However, only recently this connection has been acknowledged and efforts at fully exploiting it are only starting. In this article I will briefly review the most prominent techniques used in non-perturbative strong interactions with special emphasis on its relation with Pad\'e approximants. I will then concentrate on a set of open problems outside the scope of these conventional techniques where Pad\'e approximants might be extremely useful.
1805.04098
Cristian Sierra C.F.Sierra
R. Martinez, C.F. Sierra, German Valencia
Beyond $\mathcal{R}(D^{(*)})$ with the general 2HDM-III for $b\to c\tau\nu$
27 pages, 11 figures, major changes with new analysis and plots
Phys. Rev. D 98, 115012 (2018)
10.1103/PhysRevD.98.115012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the parameter regions allowed by measurements of $\mathcal{R}(D^{(*)})$ and by a theoretical limit on ${\cal B}(B_{c}\to\tau\nu)$ in terms of generic scalar and pseudoscalar new physics couplings, $g_s$ and $g_p$. We then use these regions as constraints to predict the ranges for additional observables in $b\to c\tau\nu$ including the differential decay distributions $d\Gamma/dq^{2}$; the ratios $\mathcal{R}(J/\psi)$ and $\mathcal{R}(\Lambda_{c})$; and the tau-lepton polarisation in $B\to D^{(\star)}\tau\nu$, with emphasis on the CP violating normal polarisation. Finally we map the allowed regions in $g_s$ and $g_p$ into the parameters of four versions of the Yukawa couplings of the general 2HDM-III model. We find that the model is still viable but could be ruled out by a confirmation of a large $\mathcal{R}(J/\psi)$.
[ { "created": "Thu, 10 May 2018 17:54:43 GMT", "version": "v1" }, { "created": "Mon, 2 Jul 2018 00:26:00 GMT", "version": "v2" }, { "created": "Fri, 24 Aug 2018 06:03:17 GMT", "version": "v3" } ]
2018-12-11
[ [ "Martinez", "R.", "" ], [ "Sierra", "C. F.", "" ], [ "Valencia", "German", "" ] ]
We review the parameter regions allowed by measurements of $\mathcal{R}(D^{(*)})$ and by a theoretical limit on ${\cal B}(B_{c}\to\tau\nu)$ in terms of generic scalar and pseudoscalar new physics couplings, $g_s$ and $g_p$. We then use these regions as constraints to predict the ranges for additional observables in $b\to c\tau\nu$ including the differential decay distributions $d\Gamma/dq^{2}$; the ratios $\mathcal{R}(J/\psi)$ and $\mathcal{R}(\Lambda_{c})$; and the tau-lepton polarisation in $B\to D^{(\star)}\tau\nu$, with emphasis on the CP violating normal polarisation. Finally we map the allowed regions in $g_s$ and $g_p$ into the parameters of four versions of the Yukawa couplings of the general 2HDM-III model. We find that the model is still viable but could be ruled out by a confirmation of a large $\mathcal{R}(J/\psi)$.
hep-ph/0403246
Peter A. Sturrock
P.A. Sturrock, D.O. Caldwell, J.D. Scargle, G. Walther, and M.S. Wheatland
Comment on "Search for periodic modulations of the solar neutrino flux in Super-Kamiokande" by J. Yoo et al
7 pages, 6 figures
null
null
null
hep-ph
null
We comment on a recent article by Yoo et al. that presents an analysis of Super-Kamiokande 10-day and 5-day data, correcting certain errors in that article. We also point out that, in using the Lomb-Scargle method of power spectrum analysis, Yoo et al. ignore much of the relevant data. A likelihood analysis, that can take account of all of the relevant data, yields evidence indicative of modulation by solar processes.
[ { "created": "Tue, 23 Mar 2004 17:43:27 GMT", "version": "v1" }, { "created": "Thu, 25 Mar 2004 00:08:00 GMT", "version": "v2" }, { "created": "Mon, 28 Jun 2004 16:53:58 GMT", "version": "v3" }, { "created": "Tue, 3 Aug 2004 16:18:41 GMT", "version": "v4" }, { "cr...
2007-05-23
[ [ "Sturrock", "P. A.", "" ], [ "Caldwell", "D. O.", "" ], [ "Scargle", "J. D.", "" ], [ "Walther", "G.", "" ], [ "Wheatland", "M. S.", "" ] ]
We comment on a recent article by Yoo et al. that presents an analysis of Super-Kamiokande 10-day and 5-day data, correcting certain errors in that article. We also point out that, in using the Lomb-Scargle method of power spectrum analysis, Yoo et al. ignore much of the relevant data. A likelihood analysis, that can take account of all of the relevant data, yields evidence indicative of modulation by solar processes.
hep-ph/0304193
Marina Nielsen
Ignacio Bediaga and Marina Nielsen
$D_s$ decays into $\phi$ and $f_0(980)$ mesons
14 pages, RevTeX4 including 5 figures in ps files
Phys.Rev.D68:036001,2003
10.1103/PhysRevD.68.036001
null
hep-ph nucl-th
null
We consider the nonleptonic and semileptonic decays of $D_s$-mesons into $\phi$ and $f_0(980)$ mesons. QCD sum rules are used to calculate the form factors associated with these decays, and the correspondig decay rates. On the basis of data on $D_s^+\to\pi^+\pi^+\pi^-$, which goes dominantly via the transition $D_s^+\to \pi^+f_0(980)$, we conclude that there is space for a sizeable light quark component on $f_0(980)$.
[ { "created": "Mon, 21 Apr 2003 13:19:55 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bediaga", "Ignacio", "" ], [ "Nielsen", "Marina", "" ] ]
We consider the nonleptonic and semileptonic decays of $D_s$-mesons into $\phi$ and $f_0(980)$ mesons. QCD sum rules are used to calculate the form factors associated with these decays, and the correspondig decay rates. On the basis of data on $D_s^+\to\pi^+\pi^+\pi^-$, which goes dominantly via the transition $D_s^+\to \pi^+f_0(980)$, we conclude that there is space for a sizeable light quark component on $f_0(980)$.
1310.6111
K. S. Babu
M. Dine (Chair), K. Babu, C. Csaki, S. Dawson, L. Dixon, S. Gottlieb, J. Harvey, D. Whiteson
The Future of U.S. Particle Theory: Report of the DPF Theory Panel
23 pages, LaTeX, Chapter 5 of the report "Planning the Future of U.S. Particle Physics (Snowmass 2013)"
null
null
null
hep-ph hep-ex hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This report summarizes the findings of the DPF Theory Panel which was formed with a goal of understanding the scientific problems and opportunities of the next decade, as well as the challenges involved in sustaining a first-class program in theoretical particle physics research in the United States.
[ { "created": "Wed, 23 Oct 2013 05:07:00 GMT", "version": "v1" }, { "created": "Sun, 26 Jan 2014 22:25:55 GMT", "version": "v2" } ]
2014-01-28
[ [ "Dine", "M.", "", "Chair" ], [ "Babu", "K.", "" ], [ "Csaki", "C.", "" ], [ "Dawson", "S.", "" ], [ "Dixon", "L.", "" ], [ "Gottlieb", "S.", "" ], [ "Harvey", "J.", "" ], [ "Whiteson", "D.",...
This report summarizes the findings of the DPF Theory Panel which was formed with a goal of understanding the scientific problems and opportunities of the next decade, as well as the challenges involved in sustaining a first-class program in theoretical particle physics research in the United States.
hep-ph/9611290
Sergei Chikanov
S. V. Chekanov, V. I. Kuvshinov
Multiparticle Clusters and Intermittent Fluctuations
13 pages, LaTeX, 3 figures, epsfig.sty, cite.sty, Presented at 5th Ann. Int. Seminar ``Non-Linear Phenomena in Complex Systems'' Minsk, Belarus, February 1996
J.Phys.G23:951-960,1997
10.1088/0954-3899/23/8/009
HEN-398
hep-ph
null
An approach for understanding the behavior of multiplicity distributions in restricted phase-space intervals derived on the basis of global observables is proposed. We obtain a unifying connection between local multiparticle clusters and the scale-invariant power-law behavior of normalized factorial moments. The model can be used to describe multiparticle processes in terms of a decomposition of the observed intermittent signal into contributions from clusters with varying number of particles.
[ { "created": "Sun, 10 Nov 1996 14:28:06 GMT", "version": "v1" }, { "created": "Thu, 19 Dec 1996 19:54:03 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chekanov", "S. V.", "" ], [ "Kuvshinov", "V. I.", "" ] ]
An approach for understanding the behavior of multiplicity distributions in restricted phase-space intervals derived on the basis of global observables is proposed. We obtain a unifying connection between local multiparticle clusters and the scale-invariant power-law behavior of normalized factorial moments. The model can be used to describe multiparticle processes in terms of a decomposition of the observed intermittent signal into contributions from clusters with varying number of particles.
0808.2044
Sebastian J\"ager
Sebastian Jager
Supersymmetry beyond minimal flavour violation
23pp. Version to appear in the EPJC special volume "Supersymmetry on the Eve of the LHC", dedicated to the memory of Julius Wess. References and brief discussion on collider signatures added
Eur.Phys.J.C59:497-520,2009
10.1140/epjc/s10052-008-0794-0
CERN-PH-TH/2008-176
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the sources and phenomenology of non-minimal flavour violation in the MSSM. We discuss in some detail the most important theoretical and experimental constraints, as well as promising observables to look for supersymmetric effects at the LHC and in the future. We emphasize the sensitivity of flavour physics to the mechanism of supersymmetry breaking and to new degrees of freedom present at fundamental scales, such as the grand unification scale. We include a discussion of present data that may hint at departures from the Standard Model.
[ { "created": "Thu, 14 Aug 2008 19:00:27 GMT", "version": "v1" }, { "created": "Tue, 18 Nov 2008 14:20:35 GMT", "version": "v2" } ]
2009-02-18
[ [ "Jager", "Sebastian", "" ] ]
We review the sources and phenomenology of non-minimal flavour violation in the MSSM. We discuss in some detail the most important theoretical and experimental constraints, as well as promising observables to look for supersymmetric effects at the LHC and in the future. We emphasize the sensitivity of flavour physics to the mechanism of supersymmetry breaking and to new degrees of freedom present at fundamental scales, such as the grand unification scale. We include a discussion of present data that may hint at departures from the Standard Model.
1308.6676
Roman Nikolaevich Lee
Roman N. Lee and Andrei A. Pomeransky
Critical points and number of master integrals
16 pages, minor changes
null
10.1007/JHEP11(2013)165
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the question about the number of master integrals for a multiloop Feynman diagram. We show that, for a given set of denominators, this number is totally determined by the critical points of the polynomials entering either of the two representations: the parametric representation and the Baikov representation. In particular, for the parametric representation the corresponding polynomial is just the sum of Symanzik polynomials. The relevant topological invariant is the sum of the Milnor numbers of the proper critical points. We present a Mathematica package Mint to automatize the counting of the master integrals.
[ { "created": "Fri, 30 Aug 2013 08:29:14 GMT", "version": "v1" }, { "created": "Fri, 6 Sep 2013 10:44:54 GMT", "version": "v2" } ]
2015-06-17
[ [ "Lee", "Roman N.", "" ], [ "Pomeransky", "Andrei A.", "" ] ]
We consider the question about the number of master integrals for a multiloop Feynman diagram. We show that, for a given set of denominators, this number is totally determined by the critical points of the polynomials entering either of the two representations: the parametric representation and the Baikov representation. In particular, for the parametric representation the corresponding polynomial is just the sum of Symanzik polynomials. The relevant topological invariant is the sum of the Milnor numbers of the proper critical points. We present a Mathematica package Mint to automatize the counting of the master integrals.
hep-ph/0607117
Munshi Golam Mustafa Dr.
Munshi G. Mustafa, Sudhir Raniwala, T. Awes, B. Rai, R. S. Bhalerao, J. G. Contreras, R. V. Gavai, S. K. Ghosh, P. Jaikumar, G. C. Mishra, A. P. Mishra, H. Mishra, B. Mohanty, J. Nayak, J-Y. Ollitrault, S. C. Phatak, L. Ramello, R. Ray, A. K. Rath, P. K. Sahu, A. M. Srivastava, D. K. Srivastava, V. K. Tiwari
Working Group Report: Heavy-Ion Physics and Quark-Gluon Plasma
20 pages, 6 eps figures, Heavy-ion physics and QGP activity report in "IX Workshop on High Energy Physics Phenomenology (WHEPP-09)" held in Institute of Physics, Bhubaneswar, India, during January 3-14, 2006. To be published in PRAMANA - Journal of Physics (Indian Academy of Science)
Pramana67:961-982,2006
10.1007/s12043-006-0106-x
SINP/TNP/06-16
hep-ph nucl-th
null
This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of Quark-Gluon Plasma believed to have created in heavy-ion collisions and in early universe are reported.
[ { "created": "Tue, 11 Jul 2006 13:45:34 GMT", "version": "v1" }, { "created": "Thu, 13 Jul 2006 12:33:30 GMT", "version": "v2" } ]
2008-11-26
[ [ "Mustafa", "Munshi G.", "" ], [ "Raniwala", "Sudhir", "" ], [ "Awes", "T.", "" ], [ "Rai", "B.", "" ], [ "Bhalerao", "R. S.", "" ], [ "Contreras", "J. G.", "" ], [ "Gavai", "R. V.", "" ], [ "Ghosh",...
This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of Quark-Gluon Plasma believed to have created in heavy-ion collisions and in early universe are reported.
hep-ph/9807495
A. Khodjamirian
A. Khodjamirian and R. R\"uckl
Exclusive Nonleptonic Decays of Heavy Mesons in QCD
11 pages, LaTex, 2 figures, epsf; talk presented by A. Khodjamirian at the 3rd Workshop ``Continuous Advances in QCD'', Minneapolis, April 1998
null
null
WUE-ITP-98-032
hep-ph
null
We use operator product expansion and QCD light-cone sum rules to estimate the amplitude of the decay $B \to J/\psi K $ taking into account leading nonfactorizable contributions. The result is very similar to the estimate obtained earlier from a four-point QCD sum rule. We discuss applications of this method to other nonleptonic $B$ decay modes.
[ { "created": "Sat, 25 Jul 1998 16:25:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Khodjamirian", "A.", "" ], [ "Rückl", "R.", "" ] ]
We use operator product expansion and QCD light-cone sum rules to estimate the amplitude of the decay $B \to J/\psi K $ taking into account leading nonfactorizable contributions. The result is very similar to the estimate obtained earlier from a four-point QCD sum rule. We discuss applications of this method to other nonleptonic $B$ decay modes.