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0801.4739
Stephen Adler
Stephen L. Adler, J. Gamboa, F. Mendez, J. Lopez-Sarrion
Axions and "Light Shining Through a Wall": A Detailed Theoretical Analysis
Latex, one eps figure, 19 pages; Added Note
AnnalsPhys.323:2851-2872,2008
10.1016/j.aop.2008.02.001
null
hep-ph
null
We give a detailed study of axion-photon and photon-axion conversion amplitudes, which enter the analysis of ``light shining through a wall'' experiments. Several different calculational methods are employed and compared, and in all cases we retain a nonzero axion mass. To leading order, we find that when the photon frequency $\omega$ is very close to the axion mass $m$, there is a threshold cusp which significantly enhances the photon to axion conversion amplitude, by a factor $\omega/\sqrt{\omega^2-m^2}$ relative to the corresponding axion to photon conversion process. When $m=0$, the enhancement factor reduces to unity and the results of previous calculations are recovered. Our calculations include an exact wave matching analysis, which shows how unitarity is maintained near threshold at $\omega=m$, and a discussion of the case when the magnetic field extends into the ``wall'' region.
[ { "created": "Wed, 30 Jan 2008 19:57:47 GMT", "version": "v1" }, { "created": "Fri, 1 Feb 2008 16:26:00 GMT", "version": "v2" }, { "created": "Tue, 26 Feb 2008 18:53:01 GMT", "version": "v3" }, { "created": "Wed, 5 Mar 2008 20:43:01 GMT", "version": "v4" } ]
2008-11-26
[ [ "Adler", "Stephen L.", "" ], [ "Gamboa", "J.", "" ], [ "Mendez", "F.", "" ], [ "Lopez-Sarrion", "J.", "" ] ]
We give a detailed study of axion-photon and photon-axion conversion amplitudes, which enter the analysis of ``light shining through a wall'' experiments. Several different calculational methods are employed and compared, and in all cases we retain a nonzero axion mass. To leading order, we find that when the photon frequency $\omega$ is very close to the axion mass $m$, there is a threshold cusp which significantly enhances the photon to axion conversion amplitude, by a factor $\omega/\sqrt{\omega^2-m^2}$ relative to the corresponding axion to photon conversion process. When $m=0$, the enhancement factor reduces to unity and the results of previous calculations are recovered. Our calculations include an exact wave matching analysis, which shows how unitarity is maintained near threshold at $\omega=m$, and a discussion of the case when the magnetic field extends into the ``wall'' region.
hep-ph/0006338
Tsou Sheung Tsun
J Bordes (Valencia), HM Chan (Rutherford Appleton Lab) and ST Tsou (Oxford)
Implications of a Rotating Mass Matrix
22 pages, Latex, figures using eps and axodraw
Phys.Rev.D63:016006,2001
10.1103/PhysRevD.63.016006
null
hep-ph
null
The fermion mass matrix, in addition to having eigenvalues (masses) which run, also changes its orientation (rotates) with changing energy scales. This means that its eigenstates at one scale will no longer be eigenstates at another scale, leading to effects where fermions of different flavours can ``transmute'' into one another. In this paper, the implications of a rotating mass matrix are analysed and possible transmuation effects are investigated both in the Standard Model (SM) and in the so-called Dualized Standard Model (DSM) that we advocate, arriving at the conclusion that some transmutational decays such as $\psi \longrightarrow \mu \tau$, $\Upsilon \longrightarrow \mu \tau$ or $\pi^0 \longrightarrow e \mu$ may be within experimental range, if not immediately, then in the near future.
[ { "created": "Thu, 29 Jun 2000 14:49:35 GMT", "version": "v1" } ]
2011-02-11
[ [ "Bordes", "J", "", "Valencia" ], [ "Chan", "HM", "", "Rutherford Appleton Lab" ], [ "Tsou", "ST", "", "Oxford" ] ]
The fermion mass matrix, in addition to having eigenvalues (masses) which run, also changes its orientation (rotates) with changing energy scales. This means that its eigenstates at one scale will no longer be eigenstates at another scale, leading to effects where fermions of different flavours can ``transmute'' into one another. In this paper, the implications of a rotating mass matrix are analysed and possible transmuation effects are investigated both in the Standard Model (SM) and in the so-called Dualized Standard Model (DSM) that we advocate, arriving at the conclusion that some transmutational decays such as $\psi \longrightarrow \mu \tau$, $\Upsilon \longrightarrow \mu \tau$ or $\pi^0 \longrightarrow e \mu$ may be within experimental range, if not immediately, then in the near future.
1010.1291
Christoph Englert
Francisco Campanario, Christoph Englert, Michael Spannowsky
Precise predictions for (non-standard) W+photon+jet production
22 pages, 14 figures, 2 tables, published version
Phys.Rev.D83:074009,2011
10.1103/PhysRevD.83.074009
FTUV-10-1004, KA-TP-30-2010, SFB/CPP-10-88
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on a detailed investigation of the next-to-leading order (NLO) QCD corrections to $W\gamma$+jet production at the Tevatron and the LHC using a fully-flexible parton-level Monte Carlo program. We include the full leptonic decay of the $W$, taking into account all off-shell and finite width effects, as well as non-standard $WW\gamma$ couplings. We find particularly sizable corrections for the currently allowed parameter range of anomalous couplings imposed by LEP data. In total the NLO differential distributions reveal a substantial phase space dependence of the corrections, leaving considerable sensitivity to anomalous couplings beyond scale uncertainty at large momentum transfers in the anomalous vertex.
[ { "created": "Wed, 6 Oct 2010 21:59:03 GMT", "version": "v1" }, { "created": "Mon, 4 Apr 2011 08:01:30 GMT", "version": "v2" } ]
2011-04-22
[ [ "Campanario", "Francisco", "" ], [ "Englert", "Christoph", "" ], [ "Spannowsky", "Michael", "" ] ]
We report on a detailed investigation of the next-to-leading order (NLO) QCD corrections to $W\gamma$+jet production at the Tevatron and the LHC using a fully-flexible parton-level Monte Carlo program. We include the full leptonic decay of the $W$, taking into account all off-shell and finite width effects, as well as non-standard $WW\gamma$ couplings. We find particularly sizable corrections for the currently allowed parameter range of anomalous couplings imposed by LEP data. In total the NLO differential distributions reveal a substantial phase space dependence of the corrections, leaving considerable sensitivity to anomalous couplings beyond scale uncertainty at large momentum transfers in the anomalous vertex.
hep-ph/9309267
Taco Nieuwenhuis
Taco Nieuwenhuis, J. A. Tjon and Yu. A. Simonov
Relativistic Two-Body Bound-State Calculations Beyond the Ladder Approximation
4 pages LaTeX and 2 uuencoded figures in PostScript; requires epsf.sty. Contributed talk at `Few Body XIV', August 23-27 1993, Amsterdam, Netherlands. Utrecht preprint THU-93/21
null
null
null
hep-ph
null
In this work the Feynman-Schwinger representation for the two-body Greens function is studied. After having given a brief introduction to the formalism, we report on the first calculations based on this formalism. In order to demonstrate the validity of the method, we consider the static case where the mass of one of the particles becomes very large. We show that the heavy particle follows a classical trajectory and we find a good agreement with the Klein-Gordon result.
[ { "created": "Wed, 15 Sep 1993 16:26:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nieuwenhuis", "Taco", "" ], [ "Tjon", "J. A.", "" ], [ "Simonov", "Yu. A.", "" ] ]
In this work the Feynman-Schwinger representation for the two-body Greens function is studied. After having given a brief introduction to the formalism, we report on the first calculations based on this formalism. In order to demonstrate the validity of the method, we consider the static case where the mass of one of the particles becomes very large. We show that the heavy particle follows a classical trajectory and we find a good agreement with the Klein-Gordon result.
0907.1412
Jose Illana
J.I. Illana, M. Masip, D. Meloni
Atmospheric lepton fluxes at ultrahigh energies
10 pages, 4 figures; published version
JCAP 0909:008,2009
10.1088/1475-7516/2009/09/008
UG-FT-254/09, CAFPE-124/09, RM3-TH/09-1
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to estimate the possibility to observe exotic physics in a neutrino telescope, it is essential to first understand the flux of atmospheric neutrinos, muons and dimuons. We study the production of these leptons by high-energy cosmic rays. We identify three main sources of muons of energy E > 10^6 GeV: the weak decay of charm and bottom mesons and the electromagnetic decay of unflavored mesons. Contrary to the standard assumption, we find that eta mesons, not the prompt decay of charm hadrons, are the dominant source of atmospheric muons at these energies. We show that, as a consequence, the ratio between the neutrino and muon fluxes is significantly reduced. For dimuons, which may be a background for long-lived staus produced near a neutrino telescope, we find that pairs of E ~ 10^7 GeV forming an angle above 10^-6 rad are produced through D (80%) or B (10%) meson decay and through Drell-Yan proceses (10%). The frequency of all these processes has been evaluated using the jet code PYTHIA.
[ { "created": "Thu, 9 Jul 2009 14:01:56 GMT", "version": "v1" }, { "created": "Wed, 9 Sep 2009 15:42:02 GMT", "version": "v2" } ]
2009-09-28
[ [ "Illana", "J. I.", "" ], [ "Masip", "M.", "" ], [ "Meloni", "D.", "" ] ]
In order to estimate the possibility to observe exotic physics in a neutrino telescope, it is essential to first understand the flux of atmospheric neutrinos, muons and dimuons. We study the production of these leptons by high-energy cosmic rays. We identify three main sources of muons of energy E > 10^6 GeV: the weak decay of charm and bottom mesons and the electromagnetic decay of unflavored mesons. Contrary to the standard assumption, we find that eta mesons, not the prompt decay of charm hadrons, are the dominant source of atmospheric muons at these energies. We show that, as a consequence, the ratio between the neutrino and muon fluxes is significantly reduced. For dimuons, which may be a background for long-lived staus produced near a neutrino telescope, we find that pairs of E ~ 10^7 GeV forming an angle above 10^-6 rad are produced through D (80%) or B (10%) meson decay and through Drell-Yan proceses (10%). The frequency of all these processes has been evaluated using the jet code PYTHIA.
1112.5276
S. V. Troitsky
Sergey V. Troitsky
Solar paraphotons
4 pages, 3 plots. Talk at the 7th Patras Workshop on Axions, WIMPs and WISPs, Mykonos, 26 June - 1 July 2011
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I revisit the question of production of paraphotons, or hidden photons, in the Sun and suggest that a simultaneous observations of solar flares by conventional instruments and by axion helioscopes may provide a discovery channel for paraphotons.
[ { "created": "Thu, 22 Dec 2011 11:05:49 GMT", "version": "v1" } ]
2011-12-23
[ [ "Troitsky", "Sergey V.", "" ] ]
I revisit the question of production of paraphotons, or hidden photons, in the Sun and suggest that a simultaneous observations of solar flares by conventional instruments and by axion helioscopes may provide a discovery channel for paraphotons.
2102.08402
Jorgivan Dias Ph.D.
J. M. Dias, G. Toledo, L. Roca, and E. Oset
Unveiling the $K_1(1270)$ double-pole structure in the $\bar{B}\to J/\psi \rho\bar{K}$ and $\bar{B}\to J/\psi \bar{K}^*\pi$ decays
26 pages, 12 figures, and 2 Tables. Manuscript published in PRD
Phys. Rev. D 103, 116019 (2021)
10.1103/PhysRevD.103.116019
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
By looking at the pseudoscalar-vector meson spectra in the $\bar{B}\to J/\psi \rho\bar{K}$ and $\bar{B}\to J/\psi \bar{K}^*\pi$ weak decays, we theoretically investigate the double-pole structure of the $K_1(1270)$ resonance by using the Chiral Unitary approach to account for the final state interactions between the pseudoscalar and vector mesons. The $K_1(1270)$ resonance appears as dynamically generated through these interactions in coupled channels and influence the shape of the invariant mass distributions under consideration. We show how those shapes are affected by the $K_1(1270)$ double-pole structure to confront the results from our model with future experiments that might investigate the $PV$ spectra in these decays.
[ { "created": "Tue, 16 Feb 2021 19:00:04 GMT", "version": "v1" }, { "created": "Wed, 21 Jul 2021 22:17:13 GMT", "version": "v2" } ]
2021-07-23
[ [ "Dias", "J. M.", "" ], [ "Toledo", "G.", "" ], [ "Roca", "L.", "" ], [ "Oset", "E.", "" ] ]
By looking at the pseudoscalar-vector meson spectra in the $\bar{B}\to J/\psi \rho\bar{K}$ and $\bar{B}\to J/\psi \bar{K}^*\pi$ weak decays, we theoretically investigate the double-pole structure of the $K_1(1270)$ resonance by using the Chiral Unitary approach to account for the final state interactions between the pseudoscalar and vector mesons. The $K_1(1270)$ resonance appears as dynamically generated through these interactions in coupled channels and influence the shape of the invariant mass distributions under consideration. We show how those shapes are affected by the $K_1(1270)$ double-pole structure to confront the results from our model with future experiments that might investigate the $PV$ spectra in these decays.
1012.4235
Kazuyuki Kanaya
Kazuyuki Kanaya
Lattice results on the phase structure and equation of state in QCD at finite temperature
6 pages, 12 figures, plenary talk given at the conference "Quark Confinement and the Hadron Spectrum IX", August 30 - September 3, 2010, Madrid, Spain; version to appear in the AIP proceedings
null
10.1063/1.3574942
UTHEP-619
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review recent developments in the studies of the phase structure and equation of state in finite temperature QCD on the lattice.
[ { "created": "Mon, 20 Dec 2010 03:34:21 GMT", "version": "v1" }, { "created": "Wed, 19 Jan 2011 08:28:51 GMT", "version": "v2" } ]
2015-05-20
[ [ "Kanaya", "Kazuyuki", "" ] ]
I review recent developments in the studies of the phase structure and equation of state in finite temperature QCD on the lattice.
hep-ph/9705462
German Valencia
Xiao-Gang He (Melbourne), G. Valencia (ISU)
Delta I=3/2 and Delta S =2 Hyperon Decays in Chiral Perturbation Theory
7 pages, Latex
Phys.Lett. B409 (1997) 469-473; Erratum-ibid. B418 (1998) 443
10.1016/S0370-2693(97)00904-0
ISU-HET-97-3
hep-ph
null
We study the Delta I =3/2 and Delta S =2 amplitudes for hyperon decays of the form (B to B(prime) pion) at lowest order in chiral perturbation theory. At this order, the Delta I=3/2 amplitudes depend on only one constant. We extract the value of this constant from experiment and find a reasonable description of these processes within experimental errors. The same constant determines the Delta S =2 transitions which, in the standard model, are too small to be observed. We find that new physics with parity odd Delta S=2 interactions can produce observable rates in hyperon decays while evading the bounds from K0 - K0(bar) mixing.
[ { "created": "Thu, 29 May 1997 15:30:42 GMT", "version": "v1" } ]
2009-10-30
[ [ "He", "Xiao-Gang", "", "Melbourne" ], [ "Valencia", "G.", "", "ISU" ] ]
We study the Delta I =3/2 and Delta S =2 amplitudes for hyperon decays of the form (B to B(prime) pion) at lowest order in chiral perturbation theory. At this order, the Delta I=3/2 amplitudes depend on only one constant. We extract the value of this constant from experiment and find a reasonable description of these processes within experimental errors. The same constant determines the Delta S =2 transitions which, in the standard model, are too small to be observed. We find that new physics with parity odd Delta S=2 interactions can produce observable rates in hyperon decays while evading the bounds from K0 - K0(bar) mixing.
hep-ph/0212209
Nanava Giso
A.Andonov, S.Jadach, G.Nanava and Z.Was
Comparison of SANC with KORALZ and PHOTOS
Submitted to Acta Physica Polonica. 9 pages, 6 figures
Acta Phys.Polon. B34 (2003) 2665-2672
null
CERN-TH/2002-315
hep-ph
null
Using the SANC system we study the one-loop electroweak standard model prediction, including virtual and real photon emissions, for the decays of on-shell vector and scalar bosons B --> f anti-f (gamma), where B is a vector boson, Z or W, or a Standard Model Higgs. The complete one-loop corrections and exact photon emission matrix element are taken into account. For the phase-space integration, the Monte Carlo technique is used. For Z decay the QED part of the calculation is first cross-checked with the exact one-loop QED prediction of KORALZ. For Higgs boson and W decays, a comparison is made with the approximate QED calculation of PHOTOS Monte Carlo. This provides a useful element for the evaluation of the theoretical uncertainty of PHOTOS, very interesting for its application in ongoing LEP2 and future LC and LHC phenomenology.
[ { "created": "Sun, 15 Dec 2002 10:02:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Andonov", "A.", "" ], [ "Jadach", "S.", "" ], [ "Nanava", "G.", "" ], [ "Was", "Z.", "" ] ]
Using the SANC system we study the one-loop electroweak standard model prediction, including virtual and real photon emissions, for the decays of on-shell vector and scalar bosons B --> f anti-f (gamma), where B is a vector boson, Z or W, or a Standard Model Higgs. The complete one-loop corrections and exact photon emission matrix element are taken into account. For the phase-space integration, the Monte Carlo technique is used. For Z decay the QED part of the calculation is first cross-checked with the exact one-loop QED prediction of KORALZ. For Higgs boson and W decays, a comparison is made with the approximate QED calculation of PHOTOS Monte Carlo. This provides a useful element for the evaluation of the theoretical uncertainty of PHOTOS, very interesting for its application in ongoing LEP2 and future LC and LHC phenomenology.
1711.00463
Jonathan Cornell
Jonathan M. Cornell (for the GAMBIT collaboration)
An overview of DarkBit, the GAMBIT dark matter module
5 pages, 4 figures. Contribution to the proceedings of TAUP 2017
J.Phys.Conf.Ser. 1342 (2020) 1, 012059
10.1088/1742-6596/1342/1/012059
gambit-proceedings-2017
hep-ph astro-ph.HE astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this conference paper, I give an overview of the capabilities of DarkBit, a module of the GAMBIT global fitting code that calculates a range of dark matter observables and corresponding experimental likelihood functions. Included in the code are limits from the dark matter relic density, multiple direct detection experiments, and indirect searches in gamma-rays and neutrinos. I discuss the capabilities of the code, and then present recent results of GAMBIT scans of the parameter space of the minimal supersymmetric standard model, with a focus on sensitivities of future dark matter searches to the current best fit regions.
[ { "created": "Wed, 1 Nov 2017 17:57:36 GMT", "version": "v1" } ]
2020-08-26
[ [ "Cornell", "Jonathan M.", "", "for the GAMBIT collaboration" ] ]
In this conference paper, I give an overview of the capabilities of DarkBit, a module of the GAMBIT global fitting code that calculates a range of dark matter observables and corresponding experimental likelihood functions. Included in the code are limits from the dark matter relic density, multiple direct detection experiments, and indirect searches in gamma-rays and neutrinos. I discuss the capabilities of the code, and then present recent results of GAMBIT scans of the parameter space of the minimal supersymmetric standard model, with a focus on sensitivities of future dark matter searches to the current best fit regions.
hep-ph/9512232
Wolfgang Hollik
W. Hollik
Tests of the Standard Model
10 pages, LaTex + 1 figure (postscript file) Plenary talk at the International Europhysics Conference on High Energy Physics, Brussels, July 27 - August 2, 1995; Complete with style-files, two misprints in table 2 corrected
null
null
KA-TP-15-1995
hep-ph
null
In this conference report a summary is given on the recent theoretical work that has contributed to improve the theoretical predictions for testing the standard model in present and future experiments. Precision calculations for the $Z$ resonance are reviewed and the status of the standard model is discussed in the light of the recent top discovery and of the results from precision experiments. Furthermore, theoretical progress for the Higgs search, for $W$ physics at LEP II, and for the anomalous magnetic moment of the muon is summarized. New Physics beyond the minimal model is briefly discussed, in particular the mimimal supersymmetric standard model in view of the recent electroweak precision data.
[ { "created": "Mon, 4 Dec 1995 15:37:51 GMT", "version": "v1" }, { "created": "Tue, 5 Dec 1995 15:37:08 GMT", "version": "v2" }, { "created": "Fri, 9 Feb 1996 15:17:14 GMT", "version": "v3" } ]
2008-02-03
[ [ "Hollik", "W.", "" ] ]
In this conference report a summary is given on the recent theoretical work that has contributed to improve the theoretical predictions for testing the standard model in present and future experiments. Precision calculations for the $Z$ resonance are reviewed and the status of the standard model is discussed in the light of the recent top discovery and of the results from precision experiments. Furthermore, theoretical progress for the Higgs search, for $W$ physics at LEP II, and for the anomalous magnetic moment of the muon is summarized. New Physics beyond the minimal model is briefly discussed, in particular the mimimal supersymmetric standard model in view of the recent electroweak precision data.
hep-ph/9610353
Juergen Berges
J. Berges
Field theory near the critical temperature
11 pages, 3 figures. Talk given at the International School of Subnuclear Physics, 34th Course: Effective Theories and Fundamental Interactions, Erice-Sicily, 3-12 July 1996
null
null
HD-THEP-96-41
hep-ph cond-mat
null
Field theory at nonvanishing temperature beyond perturbation theory is discussed for the $N$-component $O(N)$-symmetric scalar theory. We compute the effective potential directly in three dimensions using an exact evolution equation for an effective action with an infrared cutoff. A suitable truncation is solved numerically. We obtain a detailed quantitative picture of the scaling form of the equation of state in the vicinity of the critical temperature of a second order phase transition.
[ { "created": "Mon, 14 Oct 1996 15:46:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Berges", "J.", "" ] ]
Field theory at nonvanishing temperature beyond perturbation theory is discussed for the $N$-component $O(N)$-symmetric scalar theory. We compute the effective potential directly in three dimensions using an exact evolution equation for an effective action with an infrared cutoff. A suitable truncation is solved numerically. We obtain a detailed quantitative picture of the scaling form of the equation of state in the vicinity of the critical temperature of a second order phase transition.
2312.12580
Ivan Vitev
Ivan Vitev, Weiyao Ke
Initial-state and final-state effects on hadron production in small collision systems
Quark Matter 2023 Proceedings; 4 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy meson production in reactions with nuclei is an active new frontier to understand QCD dynamics and the process of hadronization in nuclear matter. Measurements in various colliding systems at RHIC and LHC, including Pb-Pb, Xe-Xe, O-O, p-Pb, and p-O, enable precision tests of the medium-size, temperature, and mass dependencies of the in-medium parton propagation and shower formation. We employ a coupled DGLAP evolution framework that takes advantage of splitting functions recently obtained in soft-collinear effective theory with Glauber gluons (SCET$_{\rm G}$) and hard thermal loop (HTL) motivated collisional energy loss effects. With jet quenching effects constrained to the nuclear modification factor of charged hadrons in Pb-Pb collisions at 5.02 TeV, we present predictions for light and heavy-meson in Xe-Xe, O-O and p-Pb collisions at the LHC. We find that the nuclear modification scales non-trivially with the quark mass and medium properties. In particular, there can be sizeable collision-induced attenuation of heavy mesons in small systems such as oxygen-oxygen and high-multiplicity p-Pb events. Finally, we analyze the impact of different models of initial-state parton dynamics on the search for QGP signatures in small colliding systems.
[ { "created": "Tue, 19 Dec 2023 20:26:57 GMT", "version": "v1" } ]
2023-12-21
[ [ "Vitev", "Ivan", "" ], [ "Ke", "Weiyao", "" ] ]
Heavy meson production in reactions with nuclei is an active new frontier to understand QCD dynamics and the process of hadronization in nuclear matter. Measurements in various colliding systems at RHIC and LHC, including Pb-Pb, Xe-Xe, O-O, p-Pb, and p-O, enable precision tests of the medium-size, temperature, and mass dependencies of the in-medium parton propagation and shower formation. We employ a coupled DGLAP evolution framework that takes advantage of splitting functions recently obtained in soft-collinear effective theory with Glauber gluons (SCET$_{\rm G}$) and hard thermal loop (HTL) motivated collisional energy loss effects. With jet quenching effects constrained to the nuclear modification factor of charged hadrons in Pb-Pb collisions at 5.02 TeV, we present predictions for light and heavy-meson in Xe-Xe, O-O and p-Pb collisions at the LHC. We find that the nuclear modification scales non-trivially with the quark mass and medium properties. In particular, there can be sizeable collision-induced attenuation of heavy mesons in small systems such as oxygen-oxygen and high-multiplicity p-Pb events. Finally, we analyze the impact of different models of initial-state parton dynamics on the search for QGP signatures in small colliding systems.
hep-ph/0209172
Elizabeth Jenkins
E. Jenkins
Charm and Bottom Baryon Masses in the 1/N Expansion
Proceedings of ICHEP2002, Amsterdam
null
10.1016/S0920-5632(03)90636-0
UCSD/PTH 02-21
hep-ph
null
The masses of heavy quark baryons are studied in an expansion in 1/N_c, SU(3) flavor symmetry breaking, and heavy-quark symmetry breaking. Very accurate model-independent mass relations are obtained for charm and bottom baryons.
[ { "created": "Mon, 16 Sep 2002 16:35:30 GMT", "version": "v1" } ]
2009-11-07
[ [ "Jenkins", "E.", "" ] ]
The masses of heavy quark baryons are studied in an expansion in 1/N_c, SU(3) flavor symmetry breaking, and heavy-quark symmetry breaking. Very accurate model-independent mass relations are obtained for charm and bottom baryons.
hep-ph/9302320
null
S. Kumano (Univ. of Mainz)
Tensor Structure Function b$_1$(x) For Spin-One Hadrons
preprint MKPH-T-93-03, 9 pages, LATEX file, Proposal for the 15 GeV European Electron Facility Project
null
null
null
hep-ph nucl-th
null
High-energy spin physics became a popular topic recently after the EMC finding for the proton's spin content. There exist unmeasured spin-dependent structure functions ($b_1$, $b_2$, $b_3$, and $b_4$) for spin-one hadrons such as the deuteron. The tensor structure function $b_1(x)$ could be measured by the proposed 15 GeV European Electron Facility. The measurement provides important clues to physics of non-nucleonic components in spin-one nuclei and to tensor structures on the quark-parton level.
[ { "created": "Sun, 28 Feb 1993 12:28:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kumano", "S.", "", "Univ. of Mainz" ] ]
High-energy spin physics became a popular topic recently after the EMC finding for the proton's spin content. There exist unmeasured spin-dependent structure functions ($b_1$, $b_2$, $b_3$, and $b_4$) for spin-one hadrons such as the deuteron. The tensor structure function $b_1(x)$ could be measured by the proposed 15 GeV European Electron Facility. The measurement provides important clues to physics of non-nucleonic components in spin-one nuclei and to tensor structures on the quark-parton level.
1711.11041
Yang-Ting Chien
Yang-Ting Chien, Alex Emerman, Shih-Chieh Hsu, Samuel Meehan and Zachery Montague
Telescoping jet substructure
5 pages, 3 figures
Phys. Rev. D 101, 114006 (2020)
10.1103/PhysRevD.101.114006
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a novel jet substructure method which exploits the variation of observables with respect to a sampling of phase-space boundaries quantified by the variability. We apply this technique to identify boosted W boson and top quark jets using telescoping subjets which utilizes information coming from subjet topology and that coming from subjet substructure. We find excellent performance of the variability, in particular its robustness against finite detector resolution. The extension to telescoping jet grooming and other telescoping jet substructure observables is also straightforward. This method provides a new direction in heavy particle tagging and suggests a systematic approach to the decomposition of jet substructure.
[ { "created": "Wed, 29 Nov 2017 19:00:00 GMT", "version": "v1" } ]
2020-07-01
[ [ "Chien", "Yang-Ting", "" ], [ "Emerman", "Alex", "" ], [ "Hsu", "Shih-Chieh", "" ], [ "Meehan", "Samuel", "" ], [ "Montague", "Zachery", "" ] ]
We introduce a novel jet substructure method which exploits the variation of observables with respect to a sampling of phase-space boundaries quantified by the variability. We apply this technique to identify boosted W boson and top quark jets using telescoping subjets which utilizes information coming from subjet topology and that coming from subjet substructure. We find excellent performance of the variability, in particular its robustness against finite detector resolution. The extension to telescoping jet grooming and other telescoping jet substructure observables is also straightforward. This method provides a new direction in heavy particle tagging and suggests a systematic approach to the decomposition of jet substructure.
hep-ph/0106010
Igor Sokalski
S.I.Klimushin, E.V.Bugaev, I.A.Sokalski (Institute for Nuclear Research, Russian Academy of Science, Moscow)
Precise parametrizations of muon energy losses in water
Contribution to the 27th ICRC (Hamburg, AUgust 7-15, 2001), 4 pages, 3 .eps figures, uses icrc.cls
null
null
null
hep-ph
null
The description of muon propagation through large depths of matter, based on a concept of the correction factor, is proposed. The results of Monte-Carlo calculations of this correction factor are presented. The parametrizations for continuous energy loss coefficients, valid in the broad interval of muon energies, and for the correction factor are given. The concrete calculations for pure water are presented.
[ { "created": "Fri, 1 Jun 2001 13:11:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Klimushin", "S. I.", "", "Institute for Nuclear\n Research, Russian Academy of Science, Moscow" ], [ "Bugaev", "E. V.", "", "Institute for Nuclear\n Research, Russian Academy of Science, Moscow" ], [ "Sokalski", "I. A.", "", "Institute for Nuclear\n Rese...
The description of muon propagation through large depths of matter, based on a concept of the correction factor, is proposed. The results of Monte-Carlo calculations of this correction factor are presented. The parametrizations for continuous energy loss coefficients, valid in the broad interval of muon energies, and for the correction factor are given. The concrete calculations for pure water are presented.
1504.07237
Yonit Hochberg
Yonit Hochberg, Yue Zhao, Kathryn M. Zurek
Superconducting Detectors for Super Light Dark Matter
6 pages, 2 figures; v2: improved detection discussion, modified benchmark model
Phys. Rev. Lett. 116, 011301 (2016)
10.1103/PhysRevLett.116.011301
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose and study a new class of superconducting detectors which are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark matter limit, mX > keV. We compute the rate of dark matter scattering off of free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with terrestrial and cosmological/astrophysical constraints could be detected by such detectors with a moderate size exposure.
[ { "created": "Mon, 27 Apr 2015 20:00:30 GMT", "version": "v1" }, { "created": "Wed, 11 Nov 2015 21:42:06 GMT", "version": "v2" } ]
2016-01-13
[ [ "Hochberg", "Yonit", "" ], [ "Zhao", "Yue", "" ], [ "Zurek", "Kathryn M.", "" ] ]
We propose and study a new class of superconducting detectors which are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark matter limit, mX > keV. We compute the rate of dark matter scattering off of free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with terrestrial and cosmological/astrophysical constraints could be detected by such detectors with a moderate size exposure.
hep-ph/0610410
Boris Ermolaev
B.I. Ermolaev, M. Greco, S.I. Troyan
Total resummation of leading logarithms vs standard description of the Polarized DIS
Talk given at 14th International Seminar on High Energy Physics: Quarks 2006, St. Petersburg, Russia, 19-25 May 2006. 4 pages, 1 figure
null
null
null
hep-ph
null
Total resummation of leading logarithms of x contributing to the spin-dependent structure function g_1 ensures its steep rise at small x. DGLAP lacks such a resummation. Instead, the DGLAP expressions for g_1 are complemented with special phenomenological fits for the initial parton densities. The singular factors x^{-\alpha} in the fits mimic the resummation and also ensure the steep (power-like) rise of g_1 at the small-x region. Furthermore, DGLAP by definition cannot describe the region of small Q^2 whereas our approach can do it.
[ { "created": "Mon, 30 Oct 2006 14:22:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ermolaev", "B. I.", "" ], [ "Greco", "M.", "" ], [ "Troyan", "S. I.", "" ] ]
Total resummation of leading logarithms of x contributing to the spin-dependent structure function g_1 ensures its steep rise at small x. DGLAP lacks such a resummation. Instead, the DGLAP expressions for g_1 are complemented with special phenomenological fits for the initial parton densities. The singular factors x^{-\alpha} in the fits mimic the resummation and also ensure the steep (power-like) rise of g_1 at the small-x region. Furthermore, DGLAP by definition cannot describe the region of small Q^2 whereas our approach can do it.
2112.04851
Ignasi Rosell
Ignasi Rosell
A new theoretical determination of $R_{\tau/P}$ $(P=\pi,K)$
Talk given at the 19th International Conference on Hadron Spectroscopy and Structure in memoriam Simon Eidelman (HADRON2021), 26-31 July (2021), Mexico City (Mexico). 5 pages, 1 figure, 1 table
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We have determined $R_{\tau/P}\equiv \Gamma(\tau \to P \nu_\tau [\gamma]) / \Gamma(P \to\mu \nu_\mu[\gamma])$ ($P=\pi, K$). Whereas $P$ decays are calculated by using Chiral Perturbation Theory (ChPT), $\tau$ decays have been studied with an effective approach where ChPT is enlarged by including the lightest resonances and following the high-energy behavior dictated by QCD. These ratios have allowed us to test the lepton universality and the CKM unitarity and also to search for bounds on non-standard interactions. Our results, $\delta R_{\tau/\pi}=(0.18\pm 0.57 )\%$ and $\delta R_{\tau/K}=(0.97\pm 0.58 )\%$, are consistent with the previous theoretical determinations, but with much more robust assumptions, yielding a reliable uncertainty.
[ { "created": "Thu, 9 Dec 2021 11:47:57 GMT", "version": "v1" } ]
2021-12-10
[ [ "Rosell", "Ignasi", "" ] ]
We have determined $R_{\tau/P}\equiv \Gamma(\tau \to P \nu_\tau [\gamma]) / \Gamma(P \to\mu \nu_\mu[\gamma])$ ($P=\pi, K$). Whereas $P$ decays are calculated by using Chiral Perturbation Theory (ChPT), $\tau$ decays have been studied with an effective approach where ChPT is enlarged by including the lightest resonances and following the high-energy behavior dictated by QCD. These ratios have allowed us to test the lepton universality and the CKM unitarity and also to search for bounds on non-standard interactions. Our results, $\delta R_{\tau/\pi}=(0.18\pm 0.57 )\%$ and $\delta R_{\tau/K}=(0.97\pm 0.58 )\%$, are consistent with the previous theoretical determinations, but with much more robust assumptions, yielding a reliable uncertainty.
2202.07738
John M. Campbell
John M. Campbell, R. Keith Ellis and Satyajit Seth
Non-local slicing approaches for NNLO QCD in MCFM
34 pages, 8 figures, published version
null
10.1007/JHEP06(2022)002
FERMILAB-PUB-22-075-T, IPPP/22/05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the implementation of several processes at Next-to-Next-to Leading Order (NNLO) accuracy in QCD in the parton-level Monte Carlo program MCFM. The processes treated are $pp\to H$, $W^\pm$, $Z$, $W^\pm H$, $ZH$, $W^\pm\gamma$, $Z\gamma$ and $\gamma\gamma$ and, for the first time in the code, $W^+W^-$, $W^\pm Z$ and $ZZ$. Decays of the unstable bosons are fully included, resulting in a flexible fully differential Monte Carlo code. The NNLO corrections have been calculated using two non-local slicing approaches, isolating the doubly unresolved region by cutting on the zero-jettiness, ${\cal T}_0$, or on $q_T$, the transverse momentum of the colour singlet final-state particles. We find that for most, but not all processes the $q_T$ slicing method leads to smaller power corrections for equal computational burden.
[ { "created": "Tue, 15 Feb 2022 21:33:21 GMT", "version": "v1" }, { "created": "Thu, 28 Jul 2022 14:06:24 GMT", "version": "v2" } ]
2022-07-29
[ [ "Campbell", "John M.", "" ], [ "Ellis", "R. Keith", "" ], [ "Seth", "Satyajit", "" ] ]
We present the implementation of several processes at Next-to-Next-to Leading Order (NNLO) accuracy in QCD in the parton-level Monte Carlo program MCFM. The processes treated are $pp\to H$, $W^\pm$, $Z$, $W^\pm H$, $ZH$, $W^\pm\gamma$, $Z\gamma$ and $\gamma\gamma$ and, for the first time in the code, $W^+W^-$, $W^\pm Z$ and $ZZ$. Decays of the unstable bosons are fully included, resulting in a flexible fully differential Monte Carlo code. The NNLO corrections have been calculated using two non-local slicing approaches, isolating the doubly unresolved region by cutting on the zero-jettiness, ${\cal T}_0$, or on $q_T$, the transverse momentum of the colour singlet final-state particles. We find that for most, but not all processes the $q_T$ slicing method leads to smaller power corrections for equal computational burden.
2202.03436
Daniel Baxter
Peter Abbamonte, Daniel Baxter, Yonatan Kahn, Gordan Krnjaic, Noah Kurinsky, Bashi Mandava, Lucas K. Wagner
Revisiting the Dark Matter Interpretation of Excess Rates in Semiconductors
9 pages, 3 figures
Phys. Rev. D 105, 123002 (2022)
10.1103/PhysRevD.105.123002
FERMILAB-PUB-22-044-PPD-QIS-T
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In light of recent results from low-threshold dark matter detectors, we revisit the possibility of a common dark matter origin for multiple excesses across numerous direct detection experiments, with a focus on the excess rates in semiconductor detectors. We explore the interpretation of the low-threshold calorimetric excess rates above 40 eV in the silicon SuperCDMS Cryogenic Phonon Detector and above 100 eV in the germanium EDELWEISS Surface detector as arising from a common but unknown origin, and demonstrate a compatible fit for the observed energy spectra in both experiments, which follow a power law of index $\alpha = 3.43^{+0.11}_{-0.06}$. Despite the intriguing scaling of the normalization of these two excess rates with approximately the square of the mass number $A^2$, we argue that the possibility of common origin by dark matter scattering via nuclear recoils is strongly disfavored, even allowing for exotic condensed matter effects in an as-yet unmeasured kinematic regime, due to the unphysically-large dark matter velocity required to give comparable rates in the different energy ranges of the silicon and germanium excesses. We also investigate the possibility of inelastic nuclear scattering by cosmic ray neutrons, solar neutrinos, and photons as the origin, and quantitatively disfavor all three based on known fluxes of particles.
[ { "created": "Mon, 7 Feb 2022 19:00:00 GMT", "version": "v1" }, { "created": "Mon, 14 Feb 2022 18:50:57 GMT", "version": "v2" }, { "created": "Fri, 3 Jun 2022 23:14:09 GMT", "version": "v3" } ]
2022-06-07
[ [ "Abbamonte", "Peter", "" ], [ "Baxter", "Daniel", "" ], [ "Kahn", "Yonatan", "" ], [ "Krnjaic", "Gordan", "" ], [ "Kurinsky", "Noah", "" ], [ "Mandava", "Bashi", "" ], [ "Wagner", "Lucas K.", "" ] ]
In light of recent results from low-threshold dark matter detectors, we revisit the possibility of a common dark matter origin for multiple excesses across numerous direct detection experiments, with a focus on the excess rates in semiconductor detectors. We explore the interpretation of the low-threshold calorimetric excess rates above 40 eV in the silicon SuperCDMS Cryogenic Phonon Detector and above 100 eV in the germanium EDELWEISS Surface detector as arising from a common but unknown origin, and demonstrate a compatible fit for the observed energy spectra in both experiments, which follow a power law of index $\alpha = 3.43^{+0.11}_{-0.06}$. Despite the intriguing scaling of the normalization of these two excess rates with approximately the square of the mass number $A^2$, we argue that the possibility of common origin by dark matter scattering via nuclear recoils is strongly disfavored, even allowing for exotic condensed matter effects in an as-yet unmeasured kinematic regime, due to the unphysically-large dark matter velocity required to give comparable rates in the different energy ranges of the silicon and germanium excesses. We also investigate the possibility of inelastic nuclear scattering by cosmic ray neutrons, solar neutrinos, and photons as the origin, and quantitatively disfavor all three based on known fluxes of particles.
1402.2458
D.N. Triantafyllopoulos
E. iancu, D.N. Triantafyllopoulos
JIMWLK evolution for multi-particle production with rapidity correlations
8 pages, 6 figures, based on talk given at IS 2013, 8 - 14 Sep 2013, Illa da Toxa, Spain
null
10.1016/j.nuclphysa.2014.04.005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study multi-particle production with rapidity correlations in proton-nucleus collisions at high energy in the Color Glass Condensate framework. The high-energy evolution responsible for such correlations is governed by a generalization of the JIMWLK equation describing the simultaneous evolution of the strong nuclear color fields in the direct amplitude and the complex conjugate amplitude. This functional equation can be used to derive ordinary evolution equations for the cross-sections for particle production, but the ensuing equations appear to be too complicated to be useful in practice, including in the limit of a large number of colors Nc. We propose an alternative formulation based on a Langevin process, which is valid for generic Nc and is better suited for numerical implementations. For illustration, we present the stochastic equations which govern two gluon production with arbitrary rapidity separation.
[ { "created": "Tue, 11 Feb 2014 11:35:36 GMT", "version": "v1" } ]
2015-06-18
[ [ "iancu", "E.", "" ], [ "Triantafyllopoulos", "D. N.", "" ] ]
We study multi-particle production with rapidity correlations in proton-nucleus collisions at high energy in the Color Glass Condensate framework. The high-energy evolution responsible for such correlations is governed by a generalization of the JIMWLK equation describing the simultaneous evolution of the strong nuclear color fields in the direct amplitude and the complex conjugate amplitude. This functional equation can be used to derive ordinary evolution equations for the cross-sections for particle production, but the ensuing equations appear to be too complicated to be useful in practice, including in the limit of a large number of colors Nc. We propose an alternative formulation based on a Langevin process, which is valid for generic Nc and is better suited for numerical implementations. For illustration, we present the stochastic equations which govern two gluon production with arbitrary rapidity separation.
1711.01770
Mykhailo Konchatnij
G.I. Gakh, M.I. Konchatnij, N.P. Merenkov
The triplet photoproduction on a free electron as a possible way to search for a dark photon
24 pages, 7 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The process of the triplet production on a free electron, $\gamma e^-\to e^+e^-e^-$, has been investigated as a reaction where a dark photon, $A'$, is produced as a virtual state with subsequent decay into a $e^+e^-$-pair. This effect arises due to the so-called kinetic mixing and is characterized by the small parameter $\epsilon$ describing the coupling strength relative to the electric charge e. The search of $A'$ in this process has advantage because the background to the $A'$ signal is pure QED. This QED background is described by eight Feynman diagrams taking into account the identity of final electrons. As concern $A'$, we leave its contribution in Compton-like diagrams only since, in this case, the virtual dark photon is time-like and its propagator has the Breit-Wigner form. So, near the resonance $A'$ can manifest itself. The contribution of $A'$ in Borsellino diagrams is negligible since, in this case, the virtual dark photon is space-like, the $A'$ propagator does not peak and effect is proportional at least to $\epsilon^2$. We calculate the distributions over the invariant masses of the both produced $e^+e^-$ pairs and search for the kinematical region where the Compton-like diagrams contribution is not suppressed as compared with the Borsellino one. We estimate what value of the parameter $\epsilon$, as a function of the dark photon mass, can be obtained at given number of the measured events.
[ { "created": "Mon, 6 Nov 2017 08:10:09 GMT", "version": "v1" } ]
2017-11-07
[ [ "Gakh", "G. I.", "" ], [ "Konchatnij", "M. I.", "" ], [ "Merenkov", "N. P.", "" ] ]
The process of the triplet production on a free electron, $\gamma e^-\to e^+e^-e^-$, has been investigated as a reaction where a dark photon, $A'$, is produced as a virtual state with subsequent decay into a $e^+e^-$-pair. This effect arises due to the so-called kinetic mixing and is characterized by the small parameter $\epsilon$ describing the coupling strength relative to the electric charge e. The search of $A'$ in this process has advantage because the background to the $A'$ signal is pure QED. This QED background is described by eight Feynman diagrams taking into account the identity of final electrons. As concern $A'$, we leave its contribution in Compton-like diagrams only since, in this case, the virtual dark photon is time-like and its propagator has the Breit-Wigner form. So, near the resonance $A'$ can manifest itself. The contribution of $A'$ in Borsellino diagrams is negligible since, in this case, the virtual dark photon is space-like, the $A'$ propagator does not peak and effect is proportional at least to $\epsilon^2$. We calculate the distributions over the invariant masses of the both produced $e^+e^-$ pairs and search for the kinematical region where the Compton-like diagrams contribution is not suppressed as compared with the Borsellino one. We estimate what value of the parameter $\epsilon$, as a function of the dark photon mass, can be obtained at given number of the measured events.
2303.16959
Jim Cline
Robert P. Finemensch, Gerald X. Gilbert-Thorple
Finemensch Lectures on the Strong Interactions
99 pages, zillions of figures; submitted to Unphys.Rev.D. Any resemblance to actual persons or physics is purely coincidental. arXiv admin note: substantial text overlap with arXiv:2006.08594 by other authors. 99% text overlap with a paper by other authors, that DOES NOT EXIST!
null
null
null
hep-ph physics.hist-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
These twenty-two lectures, with exercises, comprise the extent of what was meant to be a full-year graduate-level course on the strong interactions and QCD, given at Pactech in 19$xx$-$xy$. The course was cut short by the illness that led to Finemensch's death. Several of the lectures were finalized in collaboration with Finemensch for an anticipated monograph based on the course. The others, while retaining Finemensch's idiosyncrasies, are revised similarly to those he was able to check. His distinctive approach and manner of presentation are manifest throughout. Near the end he suggests a novel, nonperturbative formulation of quantum field theory in $D$ dimensions. Supplementary material is provided in appendices and ancillary files, including verbatim transcriptions of three lectures and the corresponding audiotaped recordings.
[ { "created": "Wed, 29 Mar 2023 18:29:53 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2023 12:00:09 GMT", "version": "v2" } ]
2023-04-28
[ [ "Finemensch", "Robert P.", "" ], [ "Gilbert-Thorple", "Gerald X.", "" ] ]
These twenty-two lectures, with exercises, comprise the extent of what was meant to be a full-year graduate-level course on the strong interactions and QCD, given at Pactech in 19$xx$-$xy$. The course was cut short by the illness that led to Finemensch's death. Several of the lectures were finalized in collaboration with Finemensch for an anticipated monograph based on the course. The others, while retaining Finemensch's idiosyncrasies, are revised similarly to those he was able to check. His distinctive approach and manner of presentation are manifest throughout. Near the end he suggests a novel, nonperturbative formulation of quantum field theory in $D$ dimensions. Supplementary material is provided in appendices and ancillary files, including verbatim transcriptions of three lectures and the corresponding audiotaped recordings.
hep-ph/0111342
Osamu Yasuda
Robert J. Geller, Tatsuhiko Hara
Geophysical aspects of very long baseline neutrino experiments
8 pages, uses elsart.cls. Talk given at 3rd International Workshop on Neutrino Factory based on Muon Storage Rings (NuFACT'01), Tsukuba, Japan, 24-30 May 2001
Nucl.Instrum.Meth. A503 (2003) 187-191
10.1016/S0168-9002(03)00670-3
null
hep-ph
null
Several proposed experiments will send beams of neutrinos through the Earth along paths with a source-receiver distance of hundreds or thousands of kilometers. Knowledge of the physical properties of the medium traversed by these beams, in particular the density, will be necessary in order to properly interpret the experimental data. Present geophysical knowledge allows the average density along a path with a length of several thousand km to be estimated with an accuracy of about $\pm 5$ per cent. Physicists planning neutrino beam experiments should decide whether or not this level of uncertainty is acceptable. If greater accuracy is required, intensive geophysical research on the Earth structure along the beam path should be conducted as part of the preparatory work on the experiments.
[ { "created": "Tue, 27 Nov 2001 11:02:31 GMT", "version": "v1" } ]
2012-08-28
[ [ "Geller", "Robert J.", "" ], [ "Hara", "Tatsuhiko", "" ] ]
Several proposed experiments will send beams of neutrinos through the Earth along paths with a source-receiver distance of hundreds or thousands of kilometers. Knowledge of the physical properties of the medium traversed by these beams, in particular the density, will be necessary in order to properly interpret the experimental data. Present geophysical knowledge allows the average density along a path with a length of several thousand km to be estimated with an accuracy of about $\pm 5$ per cent. Physicists planning neutrino beam experiments should decide whether or not this level of uncertainty is acceptable. If greater accuracy is required, intensive geophysical research on the Earth structure along the beam path should be conducted as part of the preparatory work on the experiments.
2212.13761
Dagmar Bendova
D.Bendova
Predictions for future electron-ion colliders using the Balitsky--Kovchegov equation
Intended to be submit as proceedings from the Hot Quarks 2022 conference
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
This contribution presents the latest predictions for several QCD processes at low-x in the color dipole picture which are of interest for current hadron-hadron and future electron-hadron colliders. The predictions are derived using the solution to the Balitsky-Kovchegov equation for proton and nuclear targets. Two different approaches to the nuclear case are studied: a solution obtained using a newly proposed type of initial condition which represents the initial state of a given nucleus and the solutions based on an initial condition representing a proton coupled to a Glauber-Gribov prescription. The influence from the different energy evolutions of these two approaches are studied in the following photo-nuclear processes: inclusive and diffractive DIS, coherent production of a J/psi meson in ultra-peripheral collisions, and the deeply virtual Compton scattering. By comparison to the available data from HERA and the LHC and to the other models inspired by the Color Glass Condensate framework, it is demonstrated that the future measurements will be useful to discriminate among different approaches to saturation physics. The contribution was presented at the Hot Quarks 2022 - Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions, Dao House, Colorado, USA, October 11-17 2022.
[ { "created": "Wed, 28 Dec 2022 09:38:37 GMT", "version": "v1" } ]
2022-12-29
[ [ "Bendova", "D.", "" ] ]
This contribution presents the latest predictions for several QCD processes at low-x in the color dipole picture which are of interest for current hadron-hadron and future electron-hadron colliders. The predictions are derived using the solution to the Balitsky-Kovchegov equation for proton and nuclear targets. Two different approaches to the nuclear case are studied: a solution obtained using a newly proposed type of initial condition which represents the initial state of a given nucleus and the solutions based on an initial condition representing a proton coupled to a Glauber-Gribov prescription. The influence from the different energy evolutions of these two approaches are studied in the following photo-nuclear processes: inclusive and diffractive DIS, coherent production of a J/psi meson in ultra-peripheral collisions, and the deeply virtual Compton scattering. By comparison to the available data from HERA and the LHC and to the other models inspired by the Color Glass Condensate framework, it is demonstrated that the future measurements will be useful to discriminate among different approaches to saturation physics. The contribution was presented at the Hot Quarks 2022 - Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions, Dao House, Colorado, USA, October 11-17 2022.
1611.08504
Marco Drewes
Marco Drewes, Bjorn Garbrecht, Dario Gueter, Juraj Klaric
Leptogenesis: Improving predictions for experimental searches
5 pages, 2 figures, conference proceedings (ICHEP2016), August 3-10 2016, Chicago, USA
null
null
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy right handed neutrinos could not only explain the observed neutrino masses via the seesaw mechanism, but also generate the baryon asymmetry of the universe via leptogenesis due to their CP-violating interactions in the early universe. We review recent progress in the theoretical description of this nonequilibrium process. Improved calculations are particularly important for a comparison with experimental data in testable scenarios with Majorana masses below the TeV scale, in which the heavy neutrinos can be found at the LHC, in the NA62 experiment, at T2K or in future experiments, including SHiP, DUNE and experiments at the FCC, ILC or CEPC. In addition, the relevant source of CP-violation may be experimentally accessible, and the heavy neutrinos can give a sizable contribution to neutrinoless double $\beta$ decay. In these low scale leptogenesis scenarios, the matter-antimatter asymmetry is generated at temperatures when the heavy neutrinos are relativistic, and thermal corrections to the transport equations in the early universe are large.
[ { "created": "Fri, 25 Nov 2016 16:10:16 GMT", "version": "v1" } ]
2016-11-28
[ [ "Drewes", "Marco", "" ], [ "Garbrecht", "Bjorn", "" ], [ "Gueter", "Dario", "" ], [ "Klaric", "Juraj", "" ] ]
Heavy right handed neutrinos could not only explain the observed neutrino masses via the seesaw mechanism, but also generate the baryon asymmetry of the universe via leptogenesis due to their CP-violating interactions in the early universe. We review recent progress in the theoretical description of this nonequilibrium process. Improved calculations are particularly important for a comparison with experimental data in testable scenarios with Majorana masses below the TeV scale, in which the heavy neutrinos can be found at the LHC, in the NA62 experiment, at T2K or in future experiments, including SHiP, DUNE and experiments at the FCC, ILC or CEPC. In addition, the relevant source of CP-violation may be experimentally accessible, and the heavy neutrinos can give a sizable contribution to neutrinoless double $\beta$ decay. In these low scale leptogenesis scenarios, the matter-antimatter asymmetry is generated at temperatures when the heavy neutrinos are relativistic, and thermal corrections to the transport equations in the early universe are large.
1005.5393
Neil Christensen
Neil D. Christensen, Tao Han and Yingchuan Li
Testing CP Violation in ZZH Interactions at the LHC
14 pages, 13 figures, revtex4
Phys.Lett.B693:28-35,2010
10.1016/j.physletb.2010.08.008
MADPH-10-1560, NPAC-10-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study genuine CP-odd observables at the LHC to test the CP property of the ZZH interaction for a Higgs boson with mass below the threshold to a pair of gauge bosons via the process p,p -> Z,H -> l+,l-,b,bbar. We illustrate the analysis by including a CP-odd ZZH coupling, and show how to extract the CP asymmetries in the signal events. After selective kinematical cuts to suppress the SM backgrounds plus an optimal Log-likelihood analysis, we find that, with a CP violating coupling btilde = 0.25, a CP asymmetry may be established at a 3 sigma (5 sigma) level with an integrated luminosity of about 30 (50) fb^-1 at the LHC.
[ { "created": "Fri, 28 May 2010 20:21:48 GMT", "version": "v1" } ]
2014-11-21
[ [ "Christensen", "Neil D.", "" ], [ "Han", "Tao", "" ], [ "Li", "Yingchuan", "" ] ]
We study genuine CP-odd observables at the LHC to test the CP property of the ZZH interaction for a Higgs boson with mass below the threshold to a pair of gauge bosons via the process p,p -> Z,H -> l+,l-,b,bbar. We illustrate the analysis by including a CP-odd ZZH coupling, and show how to extract the CP asymmetries in the signal events. After selective kinematical cuts to suppress the SM backgrounds plus an optimal Log-likelihood analysis, we find that, with a CP violating coupling btilde = 0.25, a CP asymmetry may be established at a 3 sigma (5 sigma) level with an integrated luminosity of about 30 (50) fb^-1 at the LHC.
1302.6238
Matthew Buckley
Matthew R. Buckley, Tilman Plehn, and Michihisa Takeuchi
Buckets of Tops
14 pages, 7 figures, 5 tables
null
10.1007/JHEP08(2013)086
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Reconstructing hadronically decaying top quarks is a key challenge at the LHC, affecting a long list of Higgs analyses and new physics searches. We propose a new method of collecting jets in buckets, corresponding to top quarks and initial state radiation. This method is particularly well suited for moderate transverse momenta of the top quark, closing the gap between top taggers and traditional top reconstruction. Applying it to searches for supersymmetric top squarks we illustrate the power of buckets.
[ { "created": "Mon, 25 Feb 2013 21:00:03 GMT", "version": "v1" } ]
2015-06-15
[ [ "Buckley", "Matthew R.", "" ], [ "Plehn", "Tilman", "" ], [ "Takeuchi", "Michihisa", "" ] ]
Reconstructing hadronically decaying top quarks is a key challenge at the LHC, affecting a long list of Higgs analyses and new physics searches. We propose a new method of collecting jets in buckets, corresponding to top quarks and initial state radiation. This method is particularly well suited for moderate transverse momenta of the top quark, closing the gap between top taggers and traditional top reconstruction. Applying it to searches for supersymmetric top squarks we illustrate the power of buckets.
hep-ph/0308025
Eric Laenen
Eric Laenen (NIKHEF)
Top Quark production dynamics
Talk presented at XXXVIIIth Rencontres de Moriond, QCD and Hadronic Interactions, 2003. 4 pages, 1 figure
null
null
null
hep-ph
null
I discuss various aspects of the dynamics of top quark production both via the strong interaction (pair production) and via the charged current weak interaction (single top production).
[ { "created": "Mon, 4 Aug 2003 09:27:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Laenen", "Eric", "", "NIKHEF" ] ]
I discuss various aspects of the dynamics of top quark production both via the strong interaction (pair production) and via the charged current weak interaction (single top production).
1809.04409
Ricardo Vazquez
X. Feal, C. Pajares, and R.A. Vazquez
Thermal behavior, entanglement entropy and parton distributions
14 pages
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The apparent thermalization of the particles produced in hadronic collisions can be obtained by quantum entanglement of the partons of the initial state once a fast hard collision is produced. The scale of the hard collision is related to the thermal temperature. As the probability distribution of these events is of the form $np(n)$, as a consequence, the von Neumann entropy is larger than in the minimum bias case. The leading contribution to this entropy comes from the logarithm of the number of partons $n$, all with equal probability, making maximal the entropy. In addition there is another contribution related to the width of the parton multiplicity. Asymptotically, the entanglement entropy becomes the logarithm of $\sqrt{n}$, indicating that the number of microstates changes with energy from $n$ to $\sqrt{n}$.
[ { "created": "Wed, 12 Sep 2018 13:19:07 GMT", "version": "v1" } ]
2018-09-13
[ [ "Feal", "X.", "" ], [ "Pajares", "C.", "" ], [ "Vazquez", "R. A.", "" ] ]
The apparent thermalization of the particles produced in hadronic collisions can be obtained by quantum entanglement of the partons of the initial state once a fast hard collision is produced. The scale of the hard collision is related to the thermal temperature. As the probability distribution of these events is of the form $np(n)$, as a consequence, the von Neumann entropy is larger than in the minimum bias case. The leading contribution to this entropy comes from the logarithm of the number of partons $n$, all with equal probability, making maximal the entropy. In addition there is another contribution related to the width of the parton multiplicity. Asymptotically, the entanglement entropy becomes the logarithm of $\sqrt{n}$, indicating that the number of microstates changes with energy from $n$ to $\sqrt{n}$.
hep-ph/0511153
Shi-Lin Zhu
Tao Huang and Shi-Lin Zhu
X(1835): A Natural Candidate of $\eta^\prime$'s Second Radial Excitation
null
Phys.Rev. D73 (2006) 014023
10.1103/PhysRevD.73.014023
null
hep-ph nucl-th
null
Recently BES collaboration observed one interesting resonance X(1835). We point out that its mass, total width, production rate and decay pattern favor its assignment as the second radial excitation of $\eta^\prime$ meson very naturally.
[ { "created": "Sat, 12 Nov 2005 10:13:43 GMT", "version": "v1" } ]
2009-11-11
[ [ "Huang", "Tao", "" ], [ "Zhu", "Shi-Lin", "" ] ]
Recently BES collaboration observed one interesting resonance X(1835). We point out that its mass, total width, production rate and decay pattern favor its assignment as the second radial excitation of $\eta^\prime$ meson very naturally.
2104.02787
Joao Pacheco B. C. de Melo Dr.
R. M. Moita (Instituto Tecnol\'ogico de Aeron\'autica, DCTA, S\~ao Jos\'e dos Campos, Brazil), J. P. B. C. de Melo (Laborat\'orio de F\'isica Te\'orica e Computacional - LFTC - UCS/UNICID S\~ao Paulo, Brazil), K. Tsushima (Laborat\'orio de F\'isica Te\'orica e Computacional - LFTC - UCS/UNICID- S\~ao Paulo, Brazil), T. Frederico (Instituto Tecnol\'ogico de Aeron\'autica, DCTA, S\~ao Jos\'e dos Campos, Brazil)
Exploring the flavor content of light and heavy-light pseudoscalars
21 pages, 22 eps figures, latex PRD style, Sub. PRD (2021). To appear Phys. Rev. D (2021). All comments are welcome
null
10.1103/PhysRevD.104.096020
LFTC-20-7/59
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The electroweak properties of light and charmed D and Ds pseudoscalar mesons are investigated within a unified covariant constituent quark model. The quark-antiquark-meson vertices are assumed to have a symmetric form by the exchange of quark momenta, which is successful in describing the light pseudoscalar meson properties. The flavor decomposition of the elastic electromagnetic form factors, electromagnetic charge radii, and weak decay constants are calculated. Based on the results a discussion on the SU(3) and SU(4) symmetry breaking is made and a comparison with the pion and kaon properties to highlight the Higgs contribution to the structure of these mesons.
[ { "created": "Tue, 6 Apr 2021 21:20:05 GMT", "version": "v1" }, { "created": "Fri, 19 Nov 2021 12:45:02 GMT", "version": "v2" } ]
2021-12-15
[ [ "Moita", "R. M.", "", "Instituto Tecnológico de Aeronáutica, DCTA, São\n José dos Campos, Brazil" ], [ "de Melo", "J. P. B. C.", "", "Laboratório de Física\n Teórica e Computacional - LFTC - UCS/UNICID São Paulo, Brazil" ], [ "Tsushima", "K.", "", "Laborat...
The electroweak properties of light and charmed D and Ds pseudoscalar mesons are investigated within a unified covariant constituent quark model. The quark-antiquark-meson vertices are assumed to have a symmetric form by the exchange of quark momenta, which is successful in describing the light pseudoscalar meson properties. The flavor decomposition of the elastic electromagnetic form factors, electromagnetic charge radii, and weak decay constants are calculated. Based on the results a discussion on the SU(3) and SU(4) symmetry breaking is made and a comparison with the pion and kaon properties to highlight the Higgs contribution to the structure of these mesons.
hep-ph/0608011
Eric S. Swanson
Olga Lakhina and Eric S Swanson
A Canonical Ds(2317)?
7 pages, 6 figures. References improved
Phys.Lett.B650:159-165,2007
10.1016/j.physletb.2007.01.075
null
hep-ph
null
It is shown that quark mass dependence induced by one loop corrections to the Breit-Fermi spin-dependent one gluon exchange potential permit an accurate determination of heavy-light meson masses. Thus the $D_s(2317)$ is a canonical $c\bar s$ meson in this scenario. The multiplet splitting relationship of chiral doublet models, $M(1^+)-M(1^-) = M(0^+) -M(0^-)$, holds to good accuracy in the $D$ and $D_s$ systems, but is accidental. Radiative transitions and bottom flavoured meson masses are discussed.
[ { "created": "Tue, 1 Aug 2006 17:08:42 GMT", "version": "v1" }, { "created": "Sun, 27 Aug 2006 03:09:43 GMT", "version": "v2" } ]
2008-11-26
[ [ "Lakhina", "Olga", "" ], [ "Swanson", "Eric S", "" ] ]
It is shown that quark mass dependence induced by one loop corrections to the Breit-Fermi spin-dependent one gluon exchange potential permit an accurate determination of heavy-light meson masses. Thus the $D_s(2317)$ is a canonical $c\bar s$ meson in this scenario. The multiplet splitting relationship of chiral doublet models, $M(1^+)-M(1^-) = M(0^+) -M(0^-)$, holds to good accuracy in the $D$ and $D_s$ systems, but is accidental. Radiative transitions and bottom flavoured meson masses are discussed.
2309.12918
Gerrit Bickendorf
Gerrit Bickendorf, Manuel Drees, Gregor Kasieczka, Claudius Krause, David Shih
Combining Resonant and Tail-based Anomaly Detection
13 pages, 15 figures
null
10.1103/PhysRevD.109.096031
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In many well-motivated models of the electroweak scale, cascade decays of new particles can result in highly boosted hadronic resonances (e.g. $Z/W/h$). This can make these models rich and promising targets for recently developed resonant anomaly detection methods powered by modern machine learning. We demonstrate this using the state-of-the-art CATHODE method applied to supersymmetry scenarios with gluino pair production. We show that CATHODE, despite being model-agnostic, is nevertheless competitive with dedicated cut-based searches, while simultaneously covering a much wider region of parameter space. The gluino events also populate the tails of the missing energy and $H_T$ distributions, making this a novel combination of resonant and tail-based anomaly detection.
[ { "created": "Fri, 22 Sep 2023 15:13:56 GMT", "version": "v1" }, { "created": "Tue, 28 May 2024 11:02:50 GMT", "version": "v2" } ]
2024-05-29
[ [ "Bickendorf", "Gerrit", "" ], [ "Drees", "Manuel", "" ], [ "Kasieczka", "Gregor", "" ], [ "Krause", "Claudius", "" ], [ "Shih", "David", "" ] ]
In many well-motivated models of the electroweak scale, cascade decays of new particles can result in highly boosted hadronic resonances (e.g. $Z/W/h$). This can make these models rich and promising targets for recently developed resonant anomaly detection methods powered by modern machine learning. We demonstrate this using the state-of-the-art CATHODE method applied to supersymmetry scenarios with gluino pair production. We show that CATHODE, despite being model-agnostic, is nevertheless competitive with dedicated cut-based searches, while simultaneously covering a much wider region of parameter space. The gluino events also populate the tails of the missing energy and $H_T$ distributions, making this a novel combination of resonant and tail-based anomaly detection.
hep-ph/0011265
Jose Bernabeu
J. Bernabeu
Hyperons, Charm and Beauty Hadrons: Conclusion and Outlook
Proceedings of the Fourth International Conference Hyperons, Charm and Beauty Hadrons 2000, Valencia, Spain v2: One reference added
Nucl.Phys.Proc.Suppl.93:369-380,2001
10.1016/S0920-5632(00)01137-3
null
hep-ph
null
In this concluding talk, the advances in the Flavour Problem studies are discussed, following the structure of the presentations in the Conference. The subjects touched are organized as follows: Baryons, K-physics, Charm and Beauty production, Charm and Beauty decays, B-Mixing and CP-Violation, Heavy Quarkonium.
[ { "created": "Tue, 21 Nov 2000 17:19:46 GMT", "version": "v1" }, { "created": "Thu, 30 Nov 2000 11:49:32 GMT", "version": "v2" } ]
2011-01-25
[ [ "Bernabeu", "J.", "" ] ]
In this concluding talk, the advances in the Flavour Problem studies are discussed, following the structure of the presentations in the Conference. The subjects touched are organized as follows: Baryons, K-physics, Charm and Beauty production, Charm and Beauty decays, B-Mixing and CP-Violation, Heavy Quarkonium.
hep-ph/0101333
D. Indumathi
R.M. Godbole (IISc., Bangalore), D. Indumathi (IMSc., Chennai), M. Kraemer (U. Edinburgh)
J/\psi production through resolved photon processes at e+ e- colliders
Added a figure on parametrisation dependence of photonic parton densities and some references
Phys.Rev.D65:074003,2002
10.1103/PhysRevD.65.074003
LC-TH-2001-019, IMSc/2001/01/02, IISc-CTS-01/01
hep-ph
null
We consider J/psi photoproduction in e+ e- as well as linear photon colliders. We find that the process is dominated by the resolved photon channel. Both the once-resolved and twice-resolved cross-sections are sensitive to (different combinations of) the colour octet matrix elements. Hence, this may be a good testing ground for colour octet contributions in NRQCD. On the other hand, the once-resolved J/psi production cross-section, particularly in a linear photon collider, is sensitive to the gluon content of the photon. Hence these cross-sections can be used to determine the parton distribution functions, especially the gluon distribution, in a photon, if the colour octet matrix elements are known.
[ { "created": "Tue, 30 Jan 2001 10:35:49 GMT", "version": "v1" }, { "created": "Wed, 3 Oct 2001 10:35:34 GMT", "version": "v2" } ]
2011-03-23
[ [ "Godbole", "R. M.", "", "IISc., Bangalore" ], [ "Indumathi", "D.", "", "IMSc., Chennai" ], [ "Kraemer", "M.", "", "U. Edinburgh" ] ]
We consider J/psi photoproduction in e+ e- as well as linear photon colliders. We find that the process is dominated by the resolved photon channel. Both the once-resolved and twice-resolved cross-sections are sensitive to (different combinations of) the colour octet matrix elements. Hence, this may be a good testing ground for colour octet contributions in NRQCD. On the other hand, the once-resolved J/psi production cross-section, particularly in a linear photon collider, is sensitive to the gluon content of the photon. Hence these cross-sections can be used to determine the parton distribution functions, especially the gluon distribution, in a photon, if the colour octet matrix elements are known.
1608.03816
Marat Siddikov Ilfatovich
Eugene Levin, Lev Lipatov and Marat Siddikov
BFKL pomeron with massive gluons and running coupling
21 pages, 11 Figures
Phys. Rev. D 94, 096004 (2016)
10.1103/PhysRevD.94.096004
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we proceed with the study of the Pomeron spectrum, by solving numerically the BFKL equation with massive gluons and running coupling. The spectrum of Regge singularities is discrete and the leading Pomeron has a considerable dependence on nonperturbative effects, for which we use Higgs mechanism as a model. We cross-checked this result with variational method and confirmed the infrared sensitivity of leading Pomeron. This fact is related to the infrared instability of the BFKL equation in QCD, with a running coupling. The subleading poles have a mild sensitivity to the soft physics, and are well described by known semiclassical methods. We also discuss the dependence on various prescriptions of the running coupling arguments.
[ { "created": "Fri, 12 Aug 2016 15:01:23 GMT", "version": "v1" } ]
2016-11-15
[ [ "Levin", "Eugene", "" ], [ "Lipatov", "Lev", "" ], [ "Siddikov", "Marat", "" ] ]
In this paper we proceed with the study of the Pomeron spectrum, by solving numerically the BFKL equation with massive gluons and running coupling. The spectrum of Regge singularities is discrete and the leading Pomeron has a considerable dependence on nonperturbative effects, for which we use Higgs mechanism as a model. We cross-checked this result with variational method and confirmed the infrared sensitivity of leading Pomeron. This fact is related to the infrared instability of the BFKL equation in QCD, with a running coupling. The subleading poles have a mild sensitivity to the soft physics, and are well described by known semiclassical methods. We also discuss the dependence on various prescriptions of the running coupling arguments.
0907.2191
Qing-Hong Cao
Edmond L. Berger, Qing-Hong Cao, Ian Low
Model Independent Constraints Among the Wtb, Zbb, and Ztt Couplings
version in Phys.Rev.D
Phys.Rev.D80:074020,2009
10.1103/PhysRevD.80.074020
ANL-HEP-PR-09-48, EFI-09-19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using an effective Lagrangian approach, we perform a model-independent analysis of the interactions among electroweak gauge bosons and the third generation quarks, i.e. the Wtb, Ztt and Zbb couplings. After one imposes the known experimental constraint on the Z b_L b_L coupling, we show that the electroweak symmetry of the standard model specifies the pattern of deviations of the Z t_L t_L and W t_L b_L couplings, independent of underlying new physics scenarios. We study implications of the predicted pattern with data on the single top quark and Ztt associated production processes at the Large Hadron Collider. Such an analysis could in principle allow for a determination of the Wtb coupling without prior knowledge of |V_{tb}|, which is otherwise difficult to achieve.
[ { "created": "Mon, 13 Jul 2009 19:27:25 GMT", "version": "v1" }, { "created": "Tue, 20 Oct 2009 15:14:15 GMT", "version": "v2" } ]
2009-11-05
[ [ "Berger", "Edmond L.", "" ], [ "Cao", "Qing-Hong", "" ], [ "Low", "Ian", "" ] ]
Using an effective Lagrangian approach, we perform a model-independent analysis of the interactions among electroweak gauge bosons and the third generation quarks, i.e. the Wtb, Ztt and Zbb couplings. After one imposes the known experimental constraint on the Z b_L b_L coupling, we show that the electroweak symmetry of the standard model specifies the pattern of deviations of the Z t_L t_L and W t_L b_L couplings, independent of underlying new physics scenarios. We study implications of the predicted pattern with data on the single top quark and Ztt associated production processes at the Large Hadron Collider. Such an analysis could in principle allow for a determination of the Wtb coupling without prior knowledge of |V_{tb}|, which is otherwise difficult to achieve.
hep-ph/9306268
Hitoshi Murayama
T. Moroi, Hitoshi Murayama and T. Yanagida
The Weinberg Angle Without Grand Unification
8 pages, TU-438
Phys.Rev.D48:2995-2997,1993
10.1103/PhysRevD.48.R2995
null
hep-ph
null
We assume that strong and electroweak interactions become strong at very high energies. With this assumption, we compute the low-energy gauge coupling constants $\alpha_i (m_Z)$ as a function of the cutoff scale, taking the supersymmetric standard model with $3+2n$ families of quark and lepton multiplets. We find that only the five family case $(n=1)$ is consistent with the experimental values of the gauge coupling constants. This suggests the presence of a pair of families at $\sim 1$~TeV.
[ { "created": "Sat, 12 Jun 1993 00:48:42 GMT", "version": "v1" } ]
2009-09-29
[ [ "Moroi", "T.", "" ], [ "Murayama", "Hitoshi", "" ], [ "Yanagida", "T.", "" ] ]
We assume that strong and electroweak interactions become strong at very high energies. With this assumption, we compute the low-energy gauge coupling constants $\alpha_i (m_Z)$ as a function of the cutoff scale, taking the supersymmetric standard model with $3+2n$ families of quark and lepton multiplets. We find that only the five family case $(n=1)$ is consistent with the experimental values of the gauge coupling constants. This suggests the presence of a pair of families at $\sim 1$~TeV.
2010.06685
Frank J. Petriello
Radja Boughezal, Chien-Yi Chen, Frank Petriello and Daniel Wiegand
Four-lepton Z-boson decay constraints on the SMEFT
17 pages, 4 figures
Phys. Rev. D 103, 055015 (2021)
10.1103/PhysRevD.103.055015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss how four-lepton decays of the Z-boson probe currently unconstrained flat directions in the parameter space of the Standard Model Effective Field Theory (SMEFT). We derive the constraints from these decays on four-lepton operators in the SMEFT and show how the LHC data for this process complements probes from neutrino-trident production. Future differential measurements with high-luminosity data can strongly constrain four-lepton operators and remove all flat directions in the four-muon sector of the SMEFT. We comment briefly on the possibility of using rare Z-decays to tau-leptons to probe untested directions in the SMEFT parameter space.
[ { "created": "Tue, 13 Oct 2020 20:58:44 GMT", "version": "v1" } ]
2021-03-24
[ [ "Boughezal", "Radja", "" ], [ "Chen", "Chien-Yi", "" ], [ "Petriello", "Frank", "" ], [ "Wiegand", "Daniel", "" ] ]
We discuss how four-lepton decays of the Z-boson probe currently unconstrained flat directions in the parameter space of the Standard Model Effective Field Theory (SMEFT). We derive the constraints from these decays on four-lepton operators in the SMEFT and show how the LHC data for this process complements probes from neutrino-trident production. Future differential measurements with high-luminosity data can strongly constrain four-lepton operators and remove all flat directions in the four-muon sector of the SMEFT. We comment briefly on the possibility of using rare Z-decays to tau-leptons to probe untested directions in the SMEFT parameter space.
hep-ph/0404040
Igor O. Cherednikov
A.E. Dorokhov, I.O. Cherednikov
Instanton effects in quark form factor and quark-quark scattering at high energy
37 pages + 9 figures; JHEP style
Annals Phys. 314 (2004) 321-361
10.1016/j.aop.2004.05.003
null
hep-ph
null
The nonperturbative effects in the high-energy processes involving strongly interacting particles are studied within the instanton liquid model of the QCD vacuum (ILM) by using the Wilson integral framework. The detailed analysis of nonperturbative contributions to the electromagnetic quark form factor is presented considering the structure of the instanton induced effects in the evolution equation describing the high energy behaviour of the form factor. It is shown that the instantons yield in high energy limit the logarithmic corrections to the amplitudes which are exponentiated in small instanton density parameter. By using the Gaussian interpolation of the constrained instanton solution, we show that the all-order multi-instanton contribution is well approximated by the weak field limit result. The role of the instantons in high energy diffractive quark-quark scattering, in particular, in formation of the soft Pomeron, is also considered. We show that within the ILM the C-odd diffractive amplitude is suppressed as 1/s compared to the C-even one. The further applications of the developed approach in studying the nonperturbative effects in high energy hadronic processes are briefly discussed.
[ { "created": "Mon, 5 Apr 2004 14:01:06 GMT", "version": "v1" } ]
2009-11-10
[ [ "Dorokhov", "A. E.", "" ], [ "Cherednikov", "I. O.", "" ] ]
The nonperturbative effects in the high-energy processes involving strongly interacting particles are studied within the instanton liquid model of the QCD vacuum (ILM) by using the Wilson integral framework. The detailed analysis of nonperturbative contributions to the electromagnetic quark form factor is presented considering the structure of the instanton induced effects in the evolution equation describing the high energy behaviour of the form factor. It is shown that the instantons yield in high energy limit the logarithmic corrections to the amplitudes which are exponentiated in small instanton density parameter. By using the Gaussian interpolation of the constrained instanton solution, we show that the all-order multi-instanton contribution is well approximated by the weak field limit result. The role of the instantons in high energy diffractive quark-quark scattering, in particular, in formation of the soft Pomeron, is also considered. We show that within the ILM the C-odd diffractive amplitude is suppressed as 1/s compared to the C-even one. The further applications of the developed approach in studying the nonperturbative effects in high energy hadronic processes are briefly discussed.
1411.3424
Xiaozhao Chen
Xiaozhao Chen and Xiaofu L\"u
Mass of Y(3940) in Bethe-Salpeter equation for quarks
19 pages, 4 figures, 1 table
null
10.1140/epjc/s10052-015-3315-y
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The general form of the Bethe-Salpeter wave functions for the bound states composed of two vector fields of arbitrary spin and definite parity is corrected. Using the revised general formalism, we investigate the observed \emph{Y}(3940) state which is considered as a molecule state consisting of $D^{*0}\bar{D}^{*0}$. Though the attractive potential between $D^{*0}$ and $\bar{D}^{*0}$ including one light meson ($\sigma$, $\pi$, $\omega$, $\rho$) exchange is considered, we find that in our approach the contribution from one-$\pi$ exchange is equal to zero and consider SU(3) symmetry breaking. The obtained mass of \emph{Y}(3940) is consistent with the experimental value.
[ { "created": "Thu, 13 Nov 2014 02:43:05 GMT", "version": "v1" } ]
2015-06-23
[ [ "Chen", "Xiaozhao", "" ], [ "Lü", "Xiaofu", "" ] ]
The general form of the Bethe-Salpeter wave functions for the bound states composed of two vector fields of arbitrary spin and definite parity is corrected. Using the revised general formalism, we investigate the observed \emph{Y}(3940) state which is considered as a molecule state consisting of $D^{*0}\bar{D}^{*0}$. Though the attractive potential between $D^{*0}$ and $\bar{D}^{*0}$ including one light meson ($\sigma$, $\pi$, $\omega$, $\rho$) exchange is considered, we find that in our approach the contribution from one-$\pi$ exchange is equal to zero and consider SU(3) symmetry breaking. The obtained mass of \emph{Y}(3940) is consistent with the experimental value.
1903.10086
David London
Alakabha Datta, Jacky Kumar and David London
The $B$ Anomalies and New Physics in $b \to s e^+ e^-$
16 pages, 5 figures. (1) Replaced all qualitative comparisons of scenarios by quantitative comparisons using p-values. (2) Removed all LFU/LFUV descriptions of scenarios, leaving only: we show the addition of NP to $b \to s e^+ e^-$ (LFUV NP) can improve the description of data. This is in contrast to other analyses, that claim that additional LFU NP is required. Made other minor changes to text
null
10.1016/j.physletb.2019.134858
UdeM-GPP-TH-19-270
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the implications of the latest LHCb measurement of $R_K$ for NP explanations of the $B$ anomalies. The previous data could be explained if the $b \to s \mu^+ \mu^-$ NP is in (I) $C_{9,{\rm NP}}^{\mu\mu}$ or (II) $C_{9,{\rm NP}}^{\mu\mu} = -C_{10,{\rm NP}}^{\mu\mu}$, with scenario (I) providing a better explanation than scenario (II). This continues to hold with the new measurement of $R_K$. However, for both scenarios, this measurement leads to a slight tension of $O(1\sigma)$ between separate fits to the $b \to s \mu^+ \mu^-$ and $R_{K^{(*)}}$ data. In this paper, we investigate whether this tension can be alleviated with the addition of NP in $b \to s e^+ e^-$. In particular, we examine the effect of adding such NP to scenarios (I) and (II). We find several scenarios in which this leads to improvements in the fits. $Z'$ and LQ models with contributions to both $b \to s \mu^+ \mu^-$ and $b \to s e^+ e^-$ can reproduce the data, but only within scenarios based on (II). If the tension persists in future measurements, it may be necessary to consider NP models with more than one particle contributing to $b \to s \ell^+ \ell^-$.
[ { "created": "Mon, 25 Mar 2019 00:23:41 GMT", "version": "v1" }, { "created": "Sun, 11 Aug 2019 17:16:09 GMT", "version": "v2" } ]
2019-08-14
[ [ "Datta", "Alakabha", "" ], [ "Kumar", "Jacky", "" ], [ "London", "David", "" ] ]
We investigate the implications of the latest LHCb measurement of $R_K$ for NP explanations of the $B$ anomalies. The previous data could be explained if the $b \to s \mu^+ \mu^-$ NP is in (I) $C_{9,{\rm NP}}^{\mu\mu}$ or (II) $C_{9,{\rm NP}}^{\mu\mu} = -C_{10,{\rm NP}}^{\mu\mu}$, with scenario (I) providing a better explanation than scenario (II). This continues to hold with the new measurement of $R_K$. However, for both scenarios, this measurement leads to a slight tension of $O(1\sigma)$ between separate fits to the $b \to s \mu^+ \mu^-$ and $R_{K^{(*)}}$ data. In this paper, we investigate whether this tension can be alleviated with the addition of NP in $b \to s e^+ e^-$. In particular, we examine the effect of adding such NP to scenarios (I) and (II). We find several scenarios in which this leads to improvements in the fits. $Z'$ and LQ models with contributions to both $b \to s \mu^+ \mu^-$ and $b \to s e^+ e^-$ can reproduce the data, but only within scenarios based on (II). If the tension persists in future measurements, it may be necessary to consider NP models with more than one particle contributing to $b \to s \ell^+ \ell^-$.
2201.02020
Jo\~ao Tiago Neves Penedo
P. P. Novichkov, J. T. Penedo, S. T. Petcov
Modular Flavour Symmetries and Modulus Stabilisation
27 pages, 4 figures, 1 table; comments and references added; matches version published in JHEP
JHEP 03 (2022) 149
10.1007/JHEP03(2022)149
SISSA 22/2021/FISI, IPMU21-0088, CFTP/21-015, IPhT-T22/005
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the problem of modulus stabilisation in the framework of the modular symmetry approach to the flavour problem. By analysing simple UV-motivated CP-invariant potentials for the modulus $\tau$ we find that a class of these potentials has (non-fine-tuned) CP-breaking minima in the vicinity of the point of $\mathbb{Z}_3^{ST}$ residual symmetry, $\tau \simeq e^{2\pi i/3}$. Stabilising the modulus at these novel minima breaks spontaneously the CP symmetry and can naturally explain the mass hierarchies of charged leptons and possibly of quarks.
[ { "created": "Thu, 6 Jan 2022 11:56:02 GMT", "version": "v1" }, { "created": "Wed, 13 Apr 2022 14:52:17 GMT", "version": "v2" } ]
2022-04-15
[ [ "Novichkov", "P. P.", "" ], [ "Penedo", "J. T.", "" ], [ "Petcov", "S. T.", "" ] ]
We study the problem of modulus stabilisation in the framework of the modular symmetry approach to the flavour problem. By analysing simple UV-motivated CP-invariant potentials for the modulus $\tau$ we find that a class of these potentials has (non-fine-tuned) CP-breaking minima in the vicinity of the point of $\mathbb{Z}_3^{ST}$ residual symmetry, $\tau \simeq e^{2\pi i/3}$. Stabilising the modulus at these novel minima breaks spontaneously the CP symmetry and can naturally explain the mass hierarchies of charged leptons and possibly of quarks.
1509.05405
Christopher W. Murphy
Benjamin Grinstein, Christopher W. Murphy
Semiclassical Approach to Heterogeneous Vacuum Decay
v3: version published in JHEP, very minor changes from v2
JHEP 1512 (2015) 063
10.1007/JHEP12(2015)063
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the decay rate of an unstable phase of a quantum field theory in the presence of an impurity in the thin-wall approximation. This derivation is based on the how the impurity changes the (flat spacetime) geometry relative to case of pure false vacuum. Two examples are given that show how to estimate some of the additional parameters that enter into this heterogeneous decay rate. This formalism is then applied to the Higgs vacuum of the Standard Model (SM), where baryonic matter acts as an impurity in the electroweak Higgs vacuum. We find that the probability for heterogeneous vacuum decay to occur is suppressed with respect to the homogeneous case. That is to say, the conclusions drawn from the homogeneous case are not modified by the inclusion of baryonic matter in the calculation. On the other hand, we show that Beyond the Standard Model physics with a characteristic scale comparable to the scale that governs the homogeneous decay rate in the SM, can in principle lead to an enhanced decay rate.
[ { "created": "Thu, 17 Sep 2015 20:12:56 GMT", "version": "v1" }, { "created": "Mon, 26 Oct 2015 11:54:35 GMT", "version": "v2" }, { "created": "Sat, 2 Jan 2016 00:08:20 GMT", "version": "v3" } ]
2016-01-05
[ [ "Grinstein", "Benjamin", "" ], [ "Murphy", "Christopher W.", "" ] ]
We derive the decay rate of an unstable phase of a quantum field theory in the presence of an impurity in the thin-wall approximation. This derivation is based on the how the impurity changes the (flat spacetime) geometry relative to case of pure false vacuum. Two examples are given that show how to estimate some of the additional parameters that enter into this heterogeneous decay rate. This formalism is then applied to the Higgs vacuum of the Standard Model (SM), where baryonic matter acts as an impurity in the electroweak Higgs vacuum. We find that the probability for heterogeneous vacuum decay to occur is suppressed with respect to the homogeneous case. That is to say, the conclusions drawn from the homogeneous case are not modified by the inclusion of baryonic matter in the calculation. On the other hand, we show that Beyond the Standard Model physics with a characteristic scale comparable to the scale that governs the homogeneous decay rate in the SM, can in principle lead to an enhanced decay rate.
2008.12494
Christoph Bobeth
Martin Beneke, Christoph Bobeth, Yu-Ming Wang
$B_{d,s}\to\gamma\ell\bar{\ell}$ decay with an energetic photon
50 pages, LaTeX; v2: Corrected sign typos in (3.48) and (3.52), results not affected
null
10.1007/JHEP12(2020)148
TUM-HEP-1280/20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the differential branching fraction, lepton forward-backward asymmetry and direct CP asymmetry for $B_{d,s}\to\gamma\ell\bar{\ell}$ decays with an energetic photon. We employ factorization methods, which result in rigorous next-to-leading order predictions in the strong coupling at leading power in the large-energy/heavy-quark expansion, together with estimates of power corrections and a resonance parameterization of sub-leading power form factors in the region of small lepton invariant mass $q^2$. The $B_{d,s}\to\gamma\ell\bar{\ell}$ decay shares features of the charged-current decay $B_u \to \gamma\ell\bar\nu_\ell$, and the FCNC decays $B\to K^{(*)}\ell\bar\ell$. As in the former, the leading-power decay rates can be expressed in terms of the $B$-meson light-cone distribution amplitude and short-distance factors. However, similar to $B\to K^{(*)}\ell\bar\ell$, four-quark and dipole operators contribute to the $B_{d,s}\to\gamma\ell\bar{\ell}$ decay in an essential way, limiting the calculation to $q^2\lesssim 6\,$GeV$^2$ below the charmonium resonances in the lepton invariant mass spectrum. A detailed analysis of the main observables and theoretical uncertainties is presented.
[ { "created": "Fri, 28 Aug 2020 06:14:30 GMT", "version": "v1" }, { "created": "Thu, 18 Mar 2021 07:47:39 GMT", "version": "v2" } ]
2021-03-19
[ [ "Beneke", "Martin", "" ], [ "Bobeth", "Christoph", "" ], [ "Wang", "Yu-Ming", "" ] ]
We calculate the differential branching fraction, lepton forward-backward asymmetry and direct CP asymmetry for $B_{d,s}\to\gamma\ell\bar{\ell}$ decays with an energetic photon. We employ factorization methods, which result in rigorous next-to-leading order predictions in the strong coupling at leading power in the large-energy/heavy-quark expansion, together with estimates of power corrections and a resonance parameterization of sub-leading power form factors in the region of small lepton invariant mass $q^2$. The $B_{d,s}\to\gamma\ell\bar{\ell}$ decay shares features of the charged-current decay $B_u \to \gamma\ell\bar\nu_\ell$, and the FCNC decays $B\to K^{(*)}\ell\bar\ell$. As in the former, the leading-power decay rates can be expressed in terms of the $B$-meson light-cone distribution amplitude and short-distance factors. However, similar to $B\to K^{(*)}\ell\bar\ell$, four-quark and dipole operators contribute to the $B_{d,s}\to\gamma\ell\bar{\ell}$ decay in an essential way, limiting the calculation to $q^2\lesssim 6\,$GeV$^2$ below the charmonium resonances in the lepton invariant mass spectrum. A detailed analysis of the main observables and theoretical uncertainties is presented.
2405.14965
Marston Copeland
Marston Copeland and Thomas Mehen
Transverse Momentum Dependent PDFs in Chiral Effective Theory
30 pages, 5 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a theoretical framework to match transverse momentum dependent parton distribution functions (TMD PDFs) onto chiral effective theory operators. In this framework the TMD PDF is expressed as a convolution of TMD hadronic distribution functions, which describe fluctuations of initial states into intermediate hadrons in chiral perturbation theory, and short distance matching coefficients, which are the TMD PDFs of intermediate hadrons in the chiral limit. The various limits of the matching condition are explored and an operator product expansion is applied to the high energy TMD matching coefficients, allowing them to be written in terms of the collinear valence PDFs of intermediate hadrons. As an example, we calculate the isovector TMD hadronic distribution functions for the proton at leading order in the chiral expansion.
[ { "created": "Thu, 23 May 2024 18:16:04 GMT", "version": "v1" } ]
2024-05-27
[ [ "Copeland", "Marston", "" ], [ "Mehen", "Thomas", "" ] ]
We develop a theoretical framework to match transverse momentum dependent parton distribution functions (TMD PDFs) onto chiral effective theory operators. In this framework the TMD PDF is expressed as a convolution of TMD hadronic distribution functions, which describe fluctuations of initial states into intermediate hadrons in chiral perturbation theory, and short distance matching coefficients, which are the TMD PDFs of intermediate hadrons in the chiral limit. The various limits of the matching condition are explored and an operator product expansion is applied to the high energy TMD matching coefficients, allowing them to be written in terms of the collinear valence PDFs of intermediate hadrons. As an example, we calculate the isovector TMD hadronic distribution functions for the proton at leading order in the chiral expansion.
2011.06480
Dimiter Hadjimichef
E. G. Pereira, C. A. Z. Vasconcellos, D. Hadjimichef
Ground Level Muon Flux Variation in a Cosmic Rays Simulation
4 pages, 1 table, 6 figures, to be published in Astronomische Nachrichten. Contribution to the Proceedings of the 9th International Workshop on Astronomy and Relativistic Astrophysics, Mexico City, Mexico, 6-12 September, 2020
null
10.1002/asna.202113940
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The oscillatory movements of atmospheric air masses has been claimed to be the origin of the muon flux variation measured at the ground level. Using a cosmic ray toolkit (CORSIKA), we simulate cascade scenarios in a time scale of a year and show the dependence of the muon flux pattern with a proposed oscillatory model atmosphere.
[ { "created": "Thu, 12 Nov 2020 16:31:42 GMT", "version": "v1" } ]
2021-03-31
[ [ "Pereira", "E. G.", "" ], [ "Vasconcellos", "C. A. Z.", "" ], [ "Hadjimichef", "D.", "" ] ]
The oscillatory movements of atmospheric air masses has been claimed to be the origin of the muon flux variation measured at the ground level. Using a cosmic ray toolkit (CORSIKA), we simulate cascade scenarios in a time scale of a year and show the dependence of the muon flux pattern with a proposed oscillatory model atmosphere.
hep-ph/0310280
Marina Nielsen
R.D. Matheus, F.S. Navarra, M. Nielsen and R. Rodrigues da Silva
$J/\psi$ couplings to open charm mesons from QCD sum rules
gluon condensate included. Version to be published at IJMPE
null
null
null
hep-ph nucl-th
null
We employ QCD sum rules to calculate the $J/\psi$ form factors and coupling constants with charmed mesons, by studying three-point correlation functions. In particular we consider the $J/\psi D^*D$ and $J/\psi DD$ vertices. We determine the momentum dependence of the form factors for kinematical conditions where J/\psi, D or D^* are off-shell. Extrapolating to the pole of each one of the so obtained form factors, we determine the coupling constants. For both couplings our results (within the errors) are compatible with estimates based on constituent quark model.
[ { "created": "Thu, 23 Oct 2003 20:30:49 GMT", "version": "v1" }, { "created": "Tue, 3 Aug 2004 14:13:09 GMT", "version": "v2" } ]
2007-05-23
[ [ "Matheus", "R. D.", "" ], [ "Navarra", "F. S.", "" ], [ "Nielsen", "M.", "" ], [ "da Silva", "R. Rodrigues", "" ] ]
We employ QCD sum rules to calculate the $J/\psi$ form factors and coupling constants with charmed mesons, by studying three-point correlation functions. In particular we consider the $J/\psi D^*D$ and $J/\psi DD$ vertices. We determine the momentum dependence of the form factors for kinematical conditions where J/\psi, D or D^* are off-shell. Extrapolating to the pole of each one of the so obtained form factors, we determine the coupling constants. For both couplings our results (within the errors) are compatible with estimates based on constituent quark model.
1512.01342
Mohammad Moosavi Nejad
S. Mohammad Moosavi Nejad and Mahdi Delpasand
Spin-dependent fragmentation functions of Gluon splitting into heavy quarkonia considering three different scenarios
16 pages, 6 figures. arXiv admin note: text overlap with arXiv:1506.08861
International Journal of Modern Physics A, Vol. 30, No. 32 (2015) 1550179
10.1142/S0217751X15501791
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy quarkonium production is a powerful implement to study the strong interaction dynamics and QCD theory. Fragmentation is the dominant production mechanism for heavy quarkonia with large transverse momentum. With the large heavy quark mass, the relative motion of the heavy quark pair inside a heavy quarkonium is effectively nonrelativistic and it is also well-known that their fragmentation functions can be calculated in the perturbative QCD framework. Here, we analytically calculate the process-independent fragmentation functions for a gluon to split into the spin-singlet and -triplet $S$-wave heavy quarkonia using three different scenarios. We will show that the fragmentation probability of the gluon into the spin-triplet bound-state is the biggest one.
[ { "created": "Fri, 4 Dec 2015 08:59:26 GMT", "version": "v1" } ]
2015-12-07
[ [ "Nejad", "S. Mohammad Moosavi", "" ], [ "Delpasand", "Mahdi", "" ] ]
Heavy quarkonium production is a powerful implement to study the strong interaction dynamics and QCD theory. Fragmentation is the dominant production mechanism for heavy quarkonia with large transverse momentum. With the large heavy quark mass, the relative motion of the heavy quark pair inside a heavy quarkonium is effectively nonrelativistic and it is also well-known that their fragmentation functions can be calculated in the perturbative QCD framework. Here, we analytically calculate the process-independent fragmentation functions for a gluon to split into the spin-singlet and -triplet $S$-wave heavy quarkonia using three different scenarios. We will show that the fragmentation probability of the gluon into the spin-triplet bound-state is the biggest one.
hep-ph/9910489
George Gogiberidze
G.L. Gogiberidze, L.K. Gelovani, E.K. Sarkisyan
On coherent particle production in central 4.3 A Gev/c Mg-Mg collisions
9 pages, 3 eps figures, LaTeX
Phys.Lett.B471:257-262,1999
10.1016/S0370-2693(99)01377-5
null
hep-ph
null
Features of dense groups, or spikes, of negative pions produced in Mg-Mg collisions at 4.3 GeV/c/nucleon are studied to search for a coherent, Cerenkov-like, mechanism of particle production process. We investigate the distributions of spike centers and, for the first time, the energy spectra of particles in spikes. The spike-center distributions are obtained to exhibit the structure due to the coherent gluon-jet emission dynamics. This structure is similar to that observed recently for all-charged-particle spikes in hadronic and nuclear interactions. The energy distribution within spikes is found to have a significant peak over the inclusive background, while the inclusive spectrum shows exponential decrease with two characteristic values of average kinetic energy. The value of the peak energy and its width are in a good agreement with those expected for pions produced in a nuclear medium in the framework of the Cerenkov quantum approach. The peak energy obtained is consistent with the value of the cross-section maximum observed in coincidence experiments of nucleon-nucleus interactions.
[ { "created": "Tue, 26 Oct 1999 14:45:53 GMT", "version": "v1" } ]
2011-08-17
[ [ "Gogiberidze", "G. L.", "" ], [ "Gelovani", "L. K.", "" ], [ "Sarkisyan", "E. K.", "" ] ]
Features of dense groups, or spikes, of negative pions produced in Mg-Mg collisions at 4.3 GeV/c/nucleon are studied to search for a coherent, Cerenkov-like, mechanism of particle production process. We investigate the distributions of spike centers and, for the first time, the energy spectra of particles in spikes. The spike-center distributions are obtained to exhibit the structure due to the coherent gluon-jet emission dynamics. This structure is similar to that observed recently for all-charged-particle spikes in hadronic and nuclear interactions. The energy distribution within spikes is found to have a significant peak over the inclusive background, while the inclusive spectrum shows exponential decrease with two characteristic values of average kinetic energy. The value of the peak energy and its width are in a good agreement with those expected for pions produced in a nuclear medium in the framework of the Cerenkov quantum approach. The peak energy obtained is consistent with the value of the cross-section maximum observed in coincidence experiments of nucleon-nucleus interactions.
1207.4930
Yue-Lin Tsai
Kingman Cheung, Yue-Lin Sming Tsai, Po-Yan Tseng, Tzu-Chiang Yuan and A. Zee
Global Study of the Simplest Scalar Phantom Dark Matter Model
Matches JCAP accepted version. 25 pages, 7 figures
null
10.1088/1475-7516/2012/10/042
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a global study of the simplest scalar phantom dark matter model. The best fit parameters of the model are determined by simultaneously imposing (i) relic density constraint from WMAP, (ii) 225 live days data from direct experiment XENON100, (iii) upper limit of gamma-ray flux from Fermi-LAT indirect detection based on dwarf spheroidal satellite galaxies, and (iv) the Higgs boson candidate with a mass about 125 GeV and its invisible branching ratio no larger than 40% if the decay of the Higgs boson into a pair of dark matter is kinematically allowed. The allowed parameter space is then used to predict annihilation cross sections for gamma-ray lines, event rates for three processes mono-b jet, single charged lepton and two charged leptons plus missing energies at the Large Hadron Collider, as well as to evaluate the muon anomalous magnetic dipole moment for the model.
[ { "created": "Fri, 20 Jul 2012 12:14:51 GMT", "version": "v1" }, { "created": "Tue, 7 Aug 2012 15:08:10 GMT", "version": "v2" }, { "created": "Tue, 23 Oct 2012 09:07:20 GMT", "version": "v3" } ]
2015-06-05
[ [ "Cheung", "Kingman", "" ], [ "Tsai", "Yue-Lin Sming", "" ], [ "Tseng", "Po-Yan", "" ], [ "Yuan", "Tzu-Chiang", "" ], [ "Zee", "A.", "" ] ]
We present a global study of the simplest scalar phantom dark matter model. The best fit parameters of the model are determined by simultaneously imposing (i) relic density constraint from WMAP, (ii) 225 live days data from direct experiment XENON100, (iii) upper limit of gamma-ray flux from Fermi-LAT indirect detection based on dwarf spheroidal satellite galaxies, and (iv) the Higgs boson candidate with a mass about 125 GeV and its invisible branching ratio no larger than 40% if the decay of the Higgs boson into a pair of dark matter is kinematically allowed. The allowed parameter space is then used to predict annihilation cross sections for gamma-ray lines, event rates for three processes mono-b jet, single charged lepton and two charged leptons plus missing energies at the Large Hadron Collider, as well as to evaluate the muon anomalous magnetic dipole moment for the model.
1604.07996
Ilkka Helenius
Ilkka Helenius, Jesper R. Christiansen and Christine O. Rasmussen
Recent Pythia 8 developments: Hard diffraction, Colour reconnection and $\gamma\gamma$ collisions
Contribution to proceedings of 7th International Workshop on Multiple Partonic Interactions at the LHC, 23 - 27 November 2015, Miramare, Trieste, Italy
null
null
LU TP 16-01, MCnet-16-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An overview of recent developments in \pythia~8 is given. First the new hard diffraction model, which is implemented as a part of the multiparton interactions (MPI) framework, is discussed. Then the new colour reconnection model, which includes beyond leading colour effects that can become important when MPI are present, is briefly reviewed. As a last topic an introduction is given to our implementation of photon-photon collisions. In particular photon PDFs, required modifications for the initial state radiation algorithm and beam remnant handling with photon beams is discussed.
[ { "created": "Wed, 27 Apr 2016 09:47:06 GMT", "version": "v1" } ]
2016-04-28
[ [ "Helenius", "Ilkka", "" ], [ "Christiansen", "Jesper R.", "" ], [ "Rasmussen", "Christine O.", "" ] ]
An overview of recent developments in \pythia~8 is given. First the new hard diffraction model, which is implemented as a part of the multiparton interactions (MPI) framework, is discussed. Then the new colour reconnection model, which includes beyond leading colour effects that can become important when MPI are present, is briefly reviewed. As a last topic an introduction is given to our implementation of photon-photon collisions. In particular photon PDFs, required modifications for the initial state radiation algorithm and beam remnant handling with photon beams is discussed.
2305.00665
Chia-Wei Liu
Hai-Yang Cheng and Chia-Wei Liu
Study of singly heavy baryon lifetimes
Accepted by JHEP, 39 pages, 4 figures
null
10.1007/JHEP07(2023)114
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We study the inclusive decay widths of singly heavy baryons with the improved bag model in which the unwanted center-of-mass motion is removed. Additional insight is gained by comparing the charmed and bottom baryons. We discuss the running of the baryon matrix elements and compare the results with the non-relativistic quark model (NRQM). While the calculated two-quark operator elements are compatible with the literature, those of the four-quark ones deviate largely. In particular, the heavy quark limit holds reasonably well in the bag model for four-quark operator matrix elements but is badly broken in the NRQM. We predict $1-\tau(\Omega_b)/ \tau(\Lambda_b^0) = (8.34\pm2.22)\%$ in accordance with the current experimental value of $(11.5^{+12.2}_{-11.6})\%$ and compatible with $(13.2\pm 4.7)\%$ obtained in the NRQM. We find an excellent agreement between theory and experiment for the lifetimes of bottom baryons. We confirm that $\Omega_c^0$ could live longer than $\Lambda_c^+$ after the dimension-7 four-quark operators are taken into account. We recommend to measure some semileptonic inclusive branching fractions in the forthcoming experiments to discern different approaches. For example, we obtain ${\cal BF} (\Xi_c^+ \to X e^+ \nu_e) = (8.57\pm 0.49)\% $ and ${\cal BF} (\Omega_c^0 \to X e^+ \nu_e) = (1.88\pm 1.69)\% $ in sharp contrast to ${\cal BF} (\Xi_c^+ \to X e^+ \nu_e) = (12.74^{+2.54}_{-2.45})\% $ and ${\cal BF} (\Omega_c^0 \to X e^+ \nu_e) = (7.59^{+2.49}_{-2.24})\% $ found in the NRQM.
[ { "created": "Mon, 1 May 2023 05:30:42 GMT", "version": "v1" }, { "created": "Tue, 2 May 2023 23:36:39 GMT", "version": "v2" }, { "created": "Fri, 7 Jul 2023 16:22:48 GMT", "version": "v3" } ]
2023-08-02
[ [ "Cheng", "Hai-Yang", "" ], [ "Liu", "Chia-Wei", "" ] ]
We study the inclusive decay widths of singly heavy baryons with the improved bag model in which the unwanted center-of-mass motion is removed. Additional insight is gained by comparing the charmed and bottom baryons. We discuss the running of the baryon matrix elements and compare the results with the non-relativistic quark model (NRQM). While the calculated two-quark operator elements are compatible with the literature, those of the four-quark ones deviate largely. In particular, the heavy quark limit holds reasonably well in the bag model for four-quark operator matrix elements but is badly broken in the NRQM. We predict $1-\tau(\Omega_b)/ \tau(\Lambda_b^0) = (8.34\pm2.22)\%$ in accordance with the current experimental value of $(11.5^{+12.2}_{-11.6})\%$ and compatible with $(13.2\pm 4.7)\%$ obtained in the NRQM. We find an excellent agreement between theory and experiment for the lifetimes of bottom baryons. We confirm that $\Omega_c^0$ could live longer than $\Lambda_c^+$ after the dimension-7 four-quark operators are taken into account. We recommend to measure some semileptonic inclusive branching fractions in the forthcoming experiments to discern different approaches. For example, we obtain ${\cal BF} (\Xi_c^+ \to X e^+ \nu_e) = (8.57\pm 0.49)\% $ and ${\cal BF} (\Omega_c^0 \to X e^+ \nu_e) = (1.88\pm 1.69)\% $ in sharp contrast to ${\cal BF} (\Xi_c^+ \to X e^+ \nu_e) = (12.74^{+2.54}_{-2.45})\% $ and ${\cal BF} (\Omega_c^0 \to X e^+ \nu_e) = (7.59^{+2.49}_{-2.24})\% $ found in the NRQM.
1905.12651
Juan Antonio Aguilar-Saavedra
J.A. Aguilar-Saavedra, F.R. Joaquim
The minimal stealth boson: models and benchmarks
LaTeX 39 pages. Additional comments. Bug corrected, final version in JHEP
null
10.1007/JHEP10(2019)237
IFT-UAM/CSIC-19-71, CFTP/19-017
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Stealth bosons are relatively light boosted particles with a cascade decay $S \to A_1 A_2 \to q \bar q q \bar q$, reconstructed as a single fat jet. In this work, we establish minimal extensions of the Standard Model that allow for such processes. Namely, we consider models containing a new (leptophobic) neutral gauge boson $Z'$ and two scalar singlets, plus extra matter required to cancel the $\text{U}(1)'$ anomalies. Our analysis shows that, depending on the model and benchmark scenario, the expected statistical significance of stealth boson signals (yet uncovered by current searches at the Large Hadron Collider) is up to nine times larger than for the most sensitive of the standard leptophobic $Z'$ signals such as dijets, $t \bar t$ pairs or dibosons. These results provide strong motivation for model-independent searches that cover these complex signals.
[ { "created": "Wed, 29 May 2019 18:02:19 GMT", "version": "v1" }, { "created": "Wed, 5 Jun 2019 15:49:04 GMT", "version": "v2" }, { "created": "Tue, 17 Sep 2019 13:42:59 GMT", "version": "v3" }, { "created": "Fri, 25 Oct 2019 10:31:03 GMT", "version": "v4" } ]
2020-01-08
[ [ "Aguilar-Saavedra", "J. A.", "" ], [ "Joaquim", "F. R.", "" ] ]
Stealth bosons are relatively light boosted particles with a cascade decay $S \to A_1 A_2 \to q \bar q q \bar q$, reconstructed as a single fat jet. In this work, we establish minimal extensions of the Standard Model that allow for such processes. Namely, we consider models containing a new (leptophobic) neutral gauge boson $Z'$ and two scalar singlets, plus extra matter required to cancel the $\text{U}(1)'$ anomalies. Our analysis shows that, depending on the model and benchmark scenario, the expected statistical significance of stealth boson signals (yet uncovered by current searches at the Large Hadron Collider) is up to nine times larger than for the most sensitive of the standard leptophobic $Z'$ signals such as dijets, $t \bar t$ pairs or dibosons. These results provide strong motivation for model-independent searches that cover these complex signals.
2205.09156
Jes\'us Bonilla
Jes\'us Bonilla
ALP one-loop corrections and nonresonant searches
4 pages, 4 figures. Contribution to the 2022 EW session of the 56th Rencontres de Moriond. arXiv admin note: substantial text overlap with arXiv:2111.14750
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the complete leading-order -- dimension five -- effective linear Lagrangian for ALPs. The full set of one-loop contributions to ALP-SM effective couplings are derived, including all finite corrections. A few phenomenological consequences of these computations are also explored as illustration, with flavour diagonal channels in the case of fermions: in particular, we explore one-loop constraints on the coupling of the ALP to top quarks. Additionally, we propose a new search for ALPs, targeting VBS processes at the LHC. For this, we consider the tree-level diboson production in VBS, where the ALP participates as an off-shell mediator. Upper limits on ALP EW couplings are obtained from a reinterpretation of Run 2 public CMS VBS analyses. Simple projections for LHC Run 3 and HL-LHC are also calculated, demonstrating the power of future dedicated analyses at ATLAS and CMS.
[ { "created": "Wed, 18 May 2022 18:11:57 GMT", "version": "v1" } ]
2022-05-20
[ [ "Bonilla", "Jesús", "" ] ]
We consider the complete leading-order -- dimension five -- effective linear Lagrangian for ALPs. The full set of one-loop contributions to ALP-SM effective couplings are derived, including all finite corrections. A few phenomenological consequences of these computations are also explored as illustration, with flavour diagonal channels in the case of fermions: in particular, we explore one-loop constraints on the coupling of the ALP to top quarks. Additionally, we propose a new search for ALPs, targeting VBS processes at the LHC. For this, we consider the tree-level diboson production in VBS, where the ALP participates as an off-shell mediator. Upper limits on ALP EW couplings are obtained from a reinterpretation of Run 2 public CMS VBS analyses. Simple projections for LHC Run 3 and HL-LHC are also calculated, demonstrating the power of future dedicated analyses at ATLAS and CMS.
0802.2412
Yasuhiro Shimizu
Mihoko M. Nojiri, Yasuhiro Shimizu, Shogo Okada, Kiyotomo Kawagoe
Inclusive transverse mass analysis for squark and gluino mass determination
21 pages, 18 figures
JHEP0806:035,2008
10.1088/1126-6708/2008/06/035
IPMU 08-0006, KEK-TH-1229
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an inclusive analysis of a stransverse mass (m_{T2}) using a hemisphere method for supersymmetry studies at the LHC . The hemisphere method is an algorithm to group collinear and high p_T particles and jets, assuming that there are two of such groups in a event. The m_{T2} is defined as a function of the unknown LSP mass, two hemisphere momenta, and missing transverse momentum. The kinematical end point of the m_{T2} distribution provides information on the squark and gluino masses. We perform a Monte Carlo simulation to study the inclusive m_{T2} distribution at the LHC. We show that the end point of the inclusive m_{T2} distribution has a cusp-like structure around the true LSP mass. The knowledge of the expected kinematical behavior near the end point for true events is important to establish the end point of the inclusive distribution. We find that the inclusive analysis is useful to obtain the information on the heaviest of the squark/gluino.
[ { "created": "Mon, 18 Feb 2008 04:03:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nojiri", "Mihoko M.", "" ], [ "Shimizu", "Yasuhiro", "" ], [ "Okada", "Shogo", "" ], [ "Kawagoe", "Kiyotomo", "" ] ]
We propose an inclusive analysis of a stransverse mass (m_{T2}) using a hemisphere method for supersymmetry studies at the LHC . The hemisphere method is an algorithm to group collinear and high p_T particles and jets, assuming that there are two of such groups in a event. The m_{T2} is defined as a function of the unknown LSP mass, two hemisphere momenta, and missing transverse momentum. The kinematical end point of the m_{T2} distribution provides information on the squark and gluino masses. We perform a Monte Carlo simulation to study the inclusive m_{T2} distribution at the LHC. We show that the end point of the inclusive m_{T2} distribution has a cusp-like structure around the true LSP mass. The knowledge of the expected kinematical behavior near the end point for true events is important to establish the end point of the inclusive distribution. We find that the inclusive analysis is useful to obtain the information on the heaviest of the squark/gluino.
hep-ph/9706286
Zhang Daxin
Paul Singer, Da-Xin Zhang
Two-photon exclusive decays $B_s \to \eta (\eta') \gamma\gamma$ and $B \to K \gamma\gamma$
11 Pages
Phys.Rev. D56 (1997) 4274-4277
10.1103/PhysRevD.56.4274
null
hep-ph
null
The exclusive decay modes $B \to K \gamma\gamma$ and $B_s \to \eta (\eta') \gamma\gamma$ are shown to have significant branching ratios of approximately $0.5\times 10^{-7}$. This first calculation of these modes employs a model based on a cascade transition $B\to V\gamma\to P\gamma\gamma$ for estimating the long-distance contribution and the process $b\to s\gamma\gamma$ for the short distance one.
[ { "created": "Sun, 8 Jun 1997 05:57:38 GMT", "version": "v1" } ]
2009-10-30
[ [ "Singer", "Paul", "" ], [ "Zhang", "Da-Xin", "" ] ]
The exclusive decay modes $B \to K \gamma\gamma$ and $B_s \to \eta (\eta') \gamma\gamma$ are shown to have significant branching ratios of approximately $0.5\times 10^{-7}$. This first calculation of these modes employs a model based on a cascade transition $B\to V\gamma\to P\gamma\gamma$ for estimating the long-distance contribution and the process $b\to s\gamma\gamma$ for the short distance one.
hep-ph/0604020
Ivan Sotsky Mr
I. Sotsky
Production of four leptons in electroweak $\gamma\gamma$ interactions
10 pages, 14 figers, 1 table
null
null
null
hep-ph
null
Detailed numerical analysis of four charged leptons photoproduction in frame of standard theory of electroweak interaction is presented. Total and differential cross sections are obtained and investigated using the Monte-Carlo method of numerical integration. Different energies of initial photons (60-2000 GeV in c.m.s.) as well as the definite and averaged spin states of interacting particles are considered. A set of kinematical cuts of linear collider experiments is discussed.
[ { "created": "Mon, 3 Apr 2006 16:00:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sotsky", "I.", "" ] ]
Detailed numerical analysis of four charged leptons photoproduction in frame of standard theory of electroweak interaction is presented. Total and differential cross sections are obtained and investigated using the Monte-Carlo method of numerical integration. Different energies of initial photons (60-2000 GeV in c.m.s.) as well as the definite and averaged spin states of interacting particles are considered. A set of kinematical cuts of linear collider experiments is discussed.
1802.05857
Fotios Diakonos K
Nikolaos G. Antoniou and Fotios K. Diakonos
Ising-QCD phenomenology close to the critical point
10 pages, 3 tables, 3 figures
null
10.1088/1361-6471/aafead
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We employ the recently introduced Ising-QCD partition function (N.~G. Antoniou {\it et al.}, Phys. Rev. D 97, 034015 (2018)) to explore in detail the behaviour of the moments of the baryon-number, within the critical region around the critical endpoint. Our analysis is based on the relation of finite-size scaling in real space with intermittency in transverse momentum space. It demonstrates in practice the recent observation (N.~G. Antoniou {\it et al.}, Phys. Rev. D 97, 034015 (2018)) that combined measurements of the intermittency index $\phi_2$ and the freeze-out parameters $\mu_b$ (baryochemical potential), $T$ (temperature), provide us with a powerful tool to detect the critical point. We also show that the finite-size scaling (FSS) region, as a part of the critical region, is very narrow in both the chemical potential and the temperature direction, even for light nuclei. Furthermore, using published experimental results for $(\mu_b,T,\phi_2)$ in A+A collisions at $\sqrt{s_{NN}}=17.2$ GeV (NA49 experiment, CERN-SPS), we are able to make a set of predictions for the freeze-out states of Ar + Sc and Xe + La collisions at the same energy in the NA61/SHINE experiment (CERN-SPS). In particular, we find that the Ar + Sc system freezes out outside the FSS region but very close to its boundary, a property which may leave characteristic traces in intermittency analysis.
[ { "created": "Fri, 16 Feb 2018 08:07:31 GMT", "version": "v1" } ]
2019-02-20
[ [ "Antoniou", "Nikolaos G.", "" ], [ "Diakonos", "Fotios K.", "" ] ]
We employ the recently introduced Ising-QCD partition function (N.~G. Antoniou {\it et al.}, Phys. Rev. D 97, 034015 (2018)) to explore in detail the behaviour of the moments of the baryon-number, within the critical region around the critical endpoint. Our analysis is based on the relation of finite-size scaling in real space with intermittency in transverse momentum space. It demonstrates in practice the recent observation (N.~G. Antoniou {\it et al.}, Phys. Rev. D 97, 034015 (2018)) that combined measurements of the intermittency index $\phi_2$ and the freeze-out parameters $\mu_b$ (baryochemical potential), $T$ (temperature), provide us with a powerful tool to detect the critical point. We also show that the finite-size scaling (FSS) region, as a part of the critical region, is very narrow in both the chemical potential and the temperature direction, even for light nuclei. Furthermore, using published experimental results for $(\mu_b,T,\phi_2)$ in A+A collisions at $\sqrt{s_{NN}}=17.2$ GeV (NA49 experiment, CERN-SPS), we are able to make a set of predictions for the freeze-out states of Ar + Sc and Xe + La collisions at the same energy in the NA61/SHINE experiment (CERN-SPS). In particular, we find that the Ar + Sc system freezes out outside the FSS region but very close to its boundary, a property which may leave characteristic traces in intermittency analysis.
1706.01411
Bo-Qiang Ma
Fang Tian, Chang Gong, Bo-Qiang Ma
Effect of sea quarks on single-spin asymmetries $A^{W^{\pm}}_{N}$ in transversely polarized pp collisions at RHIC
14 latex pages, 6 figures, final published version
Nucl. Phys. A 968 (2017) 379-390
10.1016/j.nuclphysa.2017.09.006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the single-spin asymmetries $A^{W^{\pm}}_{N}$ of $W^{\pm}$ bosons produced in transversely polarized pp collisions with the valence part of the up (u) and down (d) quark Sivers functions treated by an available parametrization and the light-cone quark spectator-diquark model respectively, while the sea part Sivers functions of u and d quarks treated as parametrization. Comparing our results with those from experimental data at RHIC, we find that the Sivers functions of sea quarks play an important role in the determination of the shapes of $A^{W^{\pm}}_{N}$. It is shown that $A^{W^{-}}_{N}$ is sensitive to u sea Sivers function, while $A^{W^{+}}_{N}$ to d sea Sivers function intuitively. The results show that the contributions of u and d sea Sivers functions are rather sizable and of the same sign, and their signs agree with that of d valence quarks and are opposite to that of u valence quarks.
[ { "created": "Mon, 5 Jun 2017 16:30:26 GMT", "version": "v1" }, { "created": "Fri, 8 Sep 2017 06:19:20 GMT", "version": "v2" }, { "created": "Fri, 22 Sep 2017 13:16:35 GMT", "version": "v3" } ]
2017-09-25
[ [ "Tian", "Fang", "" ], [ "Gong", "Chang", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We calculate the single-spin asymmetries $A^{W^{\pm}}_{N}$ of $W^{\pm}$ bosons produced in transversely polarized pp collisions with the valence part of the up (u) and down (d) quark Sivers functions treated by an available parametrization and the light-cone quark spectator-diquark model respectively, while the sea part Sivers functions of u and d quarks treated as parametrization. Comparing our results with those from experimental data at RHIC, we find that the Sivers functions of sea quarks play an important role in the determination of the shapes of $A^{W^{\pm}}_{N}$. It is shown that $A^{W^{-}}_{N}$ is sensitive to u sea Sivers function, while $A^{W^{+}}_{N}$ to d sea Sivers function intuitively. The results show that the contributions of u and d sea Sivers functions are rather sizable and of the same sign, and their signs agree with that of d valence quarks and are opposite to that of u valence quarks.
hep-ph/0510154
Miroslav Kladiva
J. Horejsi, M. Kladiva
Tree-unitarity bounds for THDM Higgs masses revisited
20 pages, 6 figures; correction to typos; will appear in Eur. Phys. J. C
Eur.Phys.J.C46:81-91,2006
10.1140/epjc/s2006-02472-3
null
hep-ph
null
We have reconsidered theoretical upper bounds on the scalar boson masses within the two-Higgs-doublet model (THDM), employing the well-known technical condition of tree-level unitarity. Our treatment provides a modest extension and generalization of some previous results of other authors. We present a rather detailed discussion of the solution of the relevant inequalities and offer some new analytic formulae as well as numerical values for the Higgs mass bounds in question. A comparison is made with the earlier results on the subject that can be found in the literature.
[ { "created": "Wed, 12 Oct 2005 16:12:32 GMT", "version": "v1" }, { "created": "Thu, 16 Mar 2006 16:21:36 GMT", "version": "v2" } ]
2009-01-07
[ [ "Horejsi", "J.", "" ], [ "Kladiva", "M.", "" ] ]
We have reconsidered theoretical upper bounds on the scalar boson masses within the two-Higgs-doublet model (THDM), employing the well-known technical condition of tree-level unitarity. Our treatment provides a modest extension and generalization of some previous results of other authors. We present a rather detailed discussion of the solution of the relevant inequalities and offer some new analytic formulae as well as numerical values for the Higgs mass bounds in question. A comparison is made with the earlier results on the subject that can be found in the literature.
1012.4224
Wei Zhu
Wei Zhu, Jianhong Ruan and Fengyao Hou
From EMC- and Cronin-effects to signals of quark-gluon plasma
35 pages, 13 figures, to be published in Int. J. Mod. Phys. E
Int. J. Mod. Phys. E Vol. 22 (2013) 1350013
10.1142/S0218301313500134
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The EMC- and Cronin-effects are explained by a unitarized evolution equation, where the shadowing and antishadowing corrections are dynamically produced by gluon fusions. For this sake, an alternative form of the GLR-MQ-ZRS equation is derived. The resulting integrated and unintegrated gluon distributions in proton and nuclei are used to analyze the contributions of the initial parton distributions to the nuclear suppression factor in heavy ion collisions. A simulation of the fractional energy loss is extracted from the RHIC and LHC data, where the contributions of the nuclear shadowing and antishadowing effects are considered. We find a rapid crossover from week energy loss to strong energy loss at a universal critical energy of gluon jet $E_c\sim 10 GeV$.
[ { "created": "Mon, 20 Dec 2010 00:43:19 GMT", "version": "v1" }, { "created": "Mon, 9 Jul 2012 02:58:37 GMT", "version": "v2" }, { "created": "Thu, 3 Jan 2013 12:32:30 GMT", "version": "v3" }, { "created": "Mon, 28 Jan 2013 10:20:53 GMT", "version": "v4" } ]
2013-01-29
[ [ "Zhu", "Wei", "" ], [ "Ruan", "Jianhong", "" ], [ "Hou", "Fengyao", "" ] ]
The EMC- and Cronin-effects are explained by a unitarized evolution equation, where the shadowing and antishadowing corrections are dynamically produced by gluon fusions. For this sake, an alternative form of the GLR-MQ-ZRS equation is derived. The resulting integrated and unintegrated gluon distributions in proton and nuclei are used to analyze the contributions of the initial parton distributions to the nuclear suppression factor in heavy ion collisions. A simulation of the fractional energy loss is extracted from the RHIC and LHC data, where the contributions of the nuclear shadowing and antishadowing effects are considered. We find a rapid crossover from week energy loss to strong energy loss at a universal critical energy of gluon jet $E_c\sim 10 GeV$.
hep-ph/0609174
Christoph L\"udeling
W. Buchm\"uller, C. L\"udeling
Field Theory and Standard Model
Lectures given at the European School of High-Energy Physics, August 2005, Kitzbuehel, Austria, to appear in the proceedings
null
null
DESY-06-151
hep-ph
null
This is a short introduction to the Standard Model and the underlying concepts of quantum field theory.
[ { "created": "Mon, 18 Sep 2006 17:30:14 GMT", "version": "v1" } ]
2016-08-16
[ [ "Buchmüller", "W.", "" ], [ "Lüdeling", "C.", "" ] ]
This is a short introduction to the Standard Model and the underlying concepts of quantum field theory.
hep-ph/0202219
Nobuchika Okada
Nobuchika Okada
Positively-deflected anomaly mediation
LaTeX2e, 13 pages, 3 figures
Phys.Rev. D65 (2002) 115009
10.1103/PhysRevD.65.115009
UMD-PP-02-035
hep-ph
null
We generalize the so-called ``deflected anomaly mediation'' scenario to the case where threshold corrections of heavy messengers to the sparticle squared-masses are positive. A concrete model realizing this scenario is also presented. The tachyonic slepton problem can be fixed with only a pair of messengers. The resultant sparticle mass spectrum is quite different from that in the conventional deflected anomaly mediation scenario, but is similar to the one in the gauge mediation scenario. The lightest sparticle is mostly B-ino.
[ { "created": "Fri, 22 Feb 2002 21:15:08 GMT", "version": "v1" } ]
2009-11-07
[ [ "Okada", "Nobuchika", "" ] ]
We generalize the so-called ``deflected anomaly mediation'' scenario to the case where threshold corrections of heavy messengers to the sparticle squared-masses are positive. A concrete model realizing this scenario is also presented. The tachyonic slepton problem can be fixed with only a pair of messengers. The resultant sparticle mass spectrum is quite different from that in the conventional deflected anomaly mediation scenario, but is similar to the one in the gauge mediation scenario. The lightest sparticle is mostly B-ino.
2002.07527
Alexey Vladimirov
Alexey A. Vladimirov and Andreas Sch\"afer
Transverse momentum dependent factorization for lattice observables
12 pages, 5 figures, double column. v2: Discussion of RAD extraction is detailed. +Minor corrections
Phys. Rev. D 101, 074517 (2020)
10.1103/PhysRevD.101.074517
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using soft collinear effective field theory, we derive the factorization theorem for the quasi-transverse-momentum-dependent (quasi-TMD) operator. We check the factorization theorem at one-loop level and compute the corresponding coefficient function and anomalous dimensions. The factorized expression is built from the physical TMD distribution, and a nonperturbative lattice related factor. We demonstrate that lattice related functions cancel in appropriately constructed ratios. These ratios could be used to explore various properties of TMD distributions, for instance, the nonperturbative evolution kernel. A discussion of such ratios and the related continuum properties of TMDs is presented.
[ { "created": "Tue, 18 Feb 2020 12:49:49 GMT", "version": "v1" }, { "created": "Sun, 26 Apr 2020 13:08:36 GMT", "version": "v2" } ]
2020-05-06
[ [ "Vladimirov", "Alexey A.", "" ], [ "Schäfer", "Andreas", "" ] ]
Using soft collinear effective field theory, we derive the factorization theorem for the quasi-transverse-momentum-dependent (quasi-TMD) operator. We check the factorization theorem at one-loop level and compute the corresponding coefficient function and anomalous dimensions. The factorized expression is built from the physical TMD distribution, and a nonperturbative lattice related factor. We demonstrate that lattice related functions cancel in appropriately constructed ratios. These ratios could be used to explore various properties of TMD distributions, for instance, the nonperturbative evolution kernel. A discussion of such ratios and the related continuum properties of TMDs is presented.
1811.03626
Aldo Deandrea
Giacomo Cacciapaglia, Eric Conte, Aldo Deandrea, Benjamin Fuks and Hua-Sheng Shao
LHC constraints and potential on resonant monotop production
22 pages, 9 figures, 3 tables
null
10.1140/epjc/s10052-019-6675-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the phenomenology associated with a resonant monotop collider signal, i.e. a signal in which a single top quark is resonantly produced in association with missing energy through an s-channel scalar exchange. We study both the bounds originating from dedicated monotop searches performed by the ATLAS and CMS experiments, and the constraints associated with other processes that could be induced by a new physics context favouring monotop production at colliders. The latter class of constraints includes, in particular, the recasting of analyses from the LHC and the TeVatron. All theoretical calculations are performed at the next-to-leading order accuracy in QCD, and we finally combine all results to establish the present limits on the parameter space and test the relevance of the monotop signal at the LHC Run 2.
[ { "created": "Thu, 8 Nov 2018 19:00:01 GMT", "version": "v1" } ]
2019-03-27
[ [ "Cacciapaglia", "Giacomo", "" ], [ "Conte", "Eric", "" ], [ "Deandrea", "Aldo", "" ], [ "Fuks", "Benjamin", "" ], [ "Shao", "Hua-Sheng", "" ] ]
We discuss the phenomenology associated with a resonant monotop collider signal, i.e. a signal in which a single top quark is resonantly produced in association with missing energy through an s-channel scalar exchange. We study both the bounds originating from dedicated monotop searches performed by the ATLAS and CMS experiments, and the constraints associated with other processes that could be induced by a new physics context favouring monotop production at colliders. The latter class of constraints includes, in particular, the recasting of analyses from the LHC and the TeVatron. All theoretical calculations are performed at the next-to-leading order accuracy in QCD, and we finally combine all results to establish the present limits on the parameter space and test the relevance of the monotop signal at the LHC Run 2.
hep-ph/0212002
Motoi Endo
Nobutaka Abe and Motoi Endo
Recent Muon g-2 Result in Deflected Anomaly-Mediated Supersymmetry Breaking
13 pages, 6 figures
Phys.Lett.B564:73-82,2003
10.1016/S0370-2693(03)00658-0
TU-676
hep-ph
null
We study the deflected anomaly-mediated supersymmetry breaking (AMSB) scenario in the light of the recent result of the muon g-2 from Brookhaven E821 experiment. The E821 result suggests the deviation from the SM prediction, though there remain unsettled uncertainties. We find that the supersymmetric contribution to the muon g-2 can be \mathcal{O}(10^{-9}), large enough to fill the deviation, with other experimental constraints satisfied. In particular, the Higgs mass and b \to s \gamma put severe constraints on the model and large \tan\beta is favored to enhance the muon g-2.
[ { "created": "Sat, 30 Nov 2002 10:38:52 GMT", "version": "v1" } ]
2014-11-17
[ [ "Abe", "Nobutaka", "" ], [ "Endo", "Motoi", "" ] ]
We study the deflected anomaly-mediated supersymmetry breaking (AMSB) scenario in the light of the recent result of the muon g-2 from Brookhaven E821 experiment. The E821 result suggests the deviation from the SM prediction, though there remain unsettled uncertainties. We find that the supersymmetric contribution to the muon g-2 can be \mathcal{O}(10^{-9}), large enough to fill the deviation, with other experimental constraints satisfied. In particular, the Higgs mass and b \to s \gamma put severe constraints on the model and large \tan\beta is favored to enhance the muon g-2.
1206.6215
Peter Kroll
P. Kroll
Transversity in exclusive electroproduction of pseudoscalar mesons
6 pages, 8 figures, using PoS.cls talk presented at QNP2012, Paris (2012)
null
null
Wu B 12-15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk it is reported on an analysis of hard exclusive electroproduction of pseudoscalar mesons within the handbag approach. It is argued that recent measurements of pion electroproduction performed by HERMES and CLAS clearly indicate the occurence of strong contributions from transversely polarized photons. Within the handbag approach such transitions are described by the transversity GPDs accompanied by twist-3 pion wave functions. It is shown that this handbag approach leads to results on cross sections and single-spin asymmetries in fair agreement with experiment. The surprising result is that the pi0 cross section is dominated by gamma_T -> pion transitions. Predictions for other pseudoscalar meson channels are also discussed.
[ { "created": "Wed, 27 Jun 2012 09:38:13 GMT", "version": "v1" } ]
2012-06-28
[ [ "Kroll", "P.", "" ] ]
In this talk it is reported on an analysis of hard exclusive electroproduction of pseudoscalar mesons within the handbag approach. It is argued that recent measurements of pion electroproduction performed by HERMES and CLAS clearly indicate the occurence of strong contributions from transversely polarized photons. Within the handbag approach such transitions are described by the transversity GPDs accompanied by twist-3 pion wave functions. It is shown that this handbag approach leads to results on cross sections and single-spin asymmetries in fair agreement with experiment. The surprising result is that the pi0 cross section is dominated by gamma_T -> pion transitions. Predictions for other pseudoscalar meson channels are also discussed.
1001.0389
Antonio Pich
Antonio Pich
Alpha_s Determination from Tau Decays: Theoretical Status
Invited talk at the Flavianet topical workshop on "Low energy constraints on extensions of the Standard Model", Kazimierz, Poland, 23-27 July 2009
Acta Phys.Polon.Supp.3:165-170,2010
null
IFIC/09-64
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The total tau hadronic width can be accurately calculated using analyticity and the operator product expansion. The result turns out to be very sensitive to the value of alpha_s(m_tau^2), providing a precise determination of the strong coupling constant. The theoretical description of this observable is updated, including the recently computed O(alpha_s^4) contributions. The experimental determination of alpha_s(m_tau^2) and its actual uncertainties are discussed.
[ { "created": "Sun, 3 Jan 2010 17:38:40 GMT", "version": "v1" } ]
2010-11-02
[ [ "Pich", "Antonio", "" ] ]
The total tau hadronic width can be accurately calculated using analyticity and the operator product expansion. The result turns out to be very sensitive to the value of alpha_s(m_tau^2), providing a precise determination of the strong coupling constant. The theoretical description of this observable is updated, including the recently computed O(alpha_s^4) contributions. The experimental determination of alpha_s(m_tau^2) and its actual uncertainties are discussed.
1707.06985
A. H. Rezaeian
Alex Kovner, Amir H. Rezaeian
DPS in CGC: Double Quark Production and Effects of Quantum Statistics
15 pages, 1 figure; v3: results unchanged, clarifying comments added. The version to appear in PRD
Phys. Rev. D 96, 074018 (2017)
10.1103/PhysRevD.96.074018
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider forward inclusive production of two quarks in the high energy p-A collisions in the CGC formalism. We demonstrate that the production cross-section is determined by the convolution of the proton generalized double transverse momentum-dependent distribution (2GTMD) functions with two independent eikonal scattering amplitudes: the product of two dipoles and a quadrupole. We explicitly demonstrate that the quadrupole amplitude term accounts for all the (initial and final state) effects of quantum statistics for identical fermions, and the correlations due to these effects. We also demonstrate that the effects due to quantum statistics (entirely encoded in the quadrupole) are parametrically leading contributions to the correlated particle production at large $N_c$. For non-identical quarks the quadrupole term also leads to correlated production which has characteristics similar to the HBT effect.
[ { "created": "Fri, 21 Jul 2017 17:32:39 GMT", "version": "v1" }, { "created": "Fri, 25 Aug 2017 15:21:47 GMT", "version": "v2" }, { "created": "Fri, 29 Sep 2017 01:56:37 GMT", "version": "v3" } ]
2017-10-20
[ [ "Kovner", "Alex", "" ], [ "Rezaeian", "Amir H.", "" ] ]
We consider forward inclusive production of two quarks in the high energy p-A collisions in the CGC formalism. We demonstrate that the production cross-section is determined by the convolution of the proton generalized double transverse momentum-dependent distribution (2GTMD) functions with two independent eikonal scattering amplitudes: the product of two dipoles and a quadrupole. We explicitly demonstrate that the quadrupole amplitude term accounts for all the (initial and final state) effects of quantum statistics for identical fermions, and the correlations due to these effects. We also demonstrate that the effects due to quantum statistics (entirely encoded in the quadrupole) are parametrically leading contributions to the correlated particle production at large $N_c$. For non-identical quarks the quadrupole term also leads to correlated production which has characteristics similar to the HBT effect.
1309.1442
Nikolaos Kidonakis
Nikolaos Kidonakis
Soft-gluon resummations and NNNLO expansions
7 pages, 7 figures; presented at EPS-HEP 2013, Stockholm, Sweden, July 18-24, 2013
PoS (EPS-HEP2013) 432
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I discuss the effectiveness of soft-gluon resummations in describing higher-order corrections. I present a comparison of recent resummation approaches and their relative successes in approximating complete NNLO corrections. I also discuss fixed-order expansions through NNNLO and present some recent applications to QCD hard-scattering processes, including top-antitop pair production, single-top production, and W production at large transverse momentum.
[ { "created": "Thu, 5 Sep 2013 19:00:55 GMT", "version": "v1" } ]
2023-02-21
[ [ "Kidonakis", "Nikolaos", "" ] ]
I discuss the effectiveness of soft-gluon resummations in describing higher-order corrections. I present a comparison of recent resummation approaches and their relative successes in approximating complete NNLO corrections. I also discuss fixed-order expansions through NNNLO and present some recent applications to QCD hard-scattering processes, including top-antitop pair production, single-top production, and W production at large transverse momentum.
hep-ph/0408139
Rabindra N. Mohapatra
H. S. Goh, R.N. Mohapatra and S. Nasri
SO(10) Symmetry Breaking and Type II Seesaw
19 pages, one figure
Phys.Rev. D70 (2004) 075022
10.1103/PhysRevD.70.075022
UMD-PP-05-009
hep-ph
null
A minimal SO(10) model with {\bf 126} Higgs field breaking B-L symmetry has been shown recently to predict large solar and atmospheric mixings in agreement with observations if it is assumed that the neutrino mass follows from the triplet dominated type II seesaw formula. No additional symmetries need to be assumed for this purpose. We discuss the conditions on the way SO(10) symmetry breaks down to MSSM and the Higgs multiplets in the model, required for the triplet dominated type II seesaw formula to hold. We find that (i) SO(10) must break to a nonminimal SU(5) before breaking to the standard model; (ii) $B-L$ symmetry must break at the time of SO(10) breaking and (iii) constraints of unification seem to require that the minimal model must have a {\bf 54} dimensional Higgs field together with a {\bf 210} and {\bf 126} to break the GUT symmetry.
[ { "created": "Wed, 11 Aug 2004 18:01:37 GMT", "version": "v1" } ]
2009-11-10
[ [ "Goh", "H. S.", "" ], [ "Mohapatra", "R. N.", "" ], [ "Nasri", "S.", "" ] ]
A minimal SO(10) model with {\bf 126} Higgs field breaking B-L symmetry has been shown recently to predict large solar and atmospheric mixings in agreement with observations if it is assumed that the neutrino mass follows from the triplet dominated type II seesaw formula. No additional symmetries need to be assumed for this purpose. We discuss the conditions on the way SO(10) symmetry breaks down to MSSM and the Higgs multiplets in the model, required for the triplet dominated type II seesaw formula to hold. We find that (i) SO(10) must break to a nonminimal SU(5) before breaking to the standard model; (ii) $B-L$ symmetry must break at the time of SO(10) breaking and (iii) constraints of unification seem to require that the minimal model must have a {\bf 54} dimensional Higgs field together with a {\bf 210} and {\bf 126} to break the GUT symmetry.
1907.10063
Aleks Smolkovi\v{c}
Aleks Smolkovi\v{c}, Michele Tammaro, Jure Zupan
Anomaly free Froggatt-Nielsen models of flavor
50 pages, 20 figures, discussion of rare meson decay bounds amended, Figs. 13, 14 and 18 updated
null
10.1007/JHEP10(2019)188
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce two anomaly free versions of Froggatt-Nielsen (FN) models, based on either $G_{\rm FN}=U(1)^3$ or $G_{\rm FN}=U(1)$ horizontal symmetries, that generate the SM quark and lepton flavor structures. The structure of these "inverted" FN models is motivated by the clockwork mechanism: the chiral fields, singlets under $G_{\rm FN}$, are supplemented by chains of vector-like fermions charged under $G_{\rm FN}$. Unlike the traditional FN models the hierarchy of quark and lepton masses is obtained as an expansion in $M/\langle \phi\rangle$, where $M$ is the typical vector-like fermion mass, and $\langle \phi\rangle$ the flavon vacuum expectation value. The models can be searched for through deviations in flavor observables such as $K-\bar K$ mixing, $\mu\to e$ conversion, etc., where the present bounds restrict the masses of vector-like fermions to be above ${\mathcal O}(10^7~{\rm GeV})$. If $G_{\rm FN}$ is gauged, the models can also be probed by searching for the flavorful $Z'$ gauge bosons. In principle, the $Z'$s can be very light, and can be searched for using precision flavor, astrophysics, and beam dump experiments.
[ { "created": "Tue, 23 Jul 2019 18:00:01 GMT", "version": "v1" }, { "created": "Thu, 14 Oct 2021 19:42:17 GMT", "version": "v2" } ]
2021-10-18
[ [ "Smolkovič", "Aleks", "" ], [ "Tammaro", "Michele", "" ], [ "Zupan", "Jure", "" ] ]
We introduce two anomaly free versions of Froggatt-Nielsen (FN) models, based on either $G_{\rm FN}=U(1)^3$ or $G_{\rm FN}=U(1)$ horizontal symmetries, that generate the SM quark and lepton flavor structures. The structure of these "inverted" FN models is motivated by the clockwork mechanism: the chiral fields, singlets under $G_{\rm FN}$, are supplemented by chains of vector-like fermions charged under $G_{\rm FN}$. Unlike the traditional FN models the hierarchy of quark and lepton masses is obtained as an expansion in $M/\langle \phi\rangle$, where $M$ is the typical vector-like fermion mass, and $\langle \phi\rangle$ the flavon vacuum expectation value. The models can be searched for through deviations in flavor observables such as $K-\bar K$ mixing, $\mu\to e$ conversion, etc., where the present bounds restrict the masses of vector-like fermions to be above ${\mathcal O}(10^7~{\rm GeV})$. If $G_{\rm FN}$ is gauged, the models can also be probed by searching for the flavorful $Z'$ gauge bosons. In principle, the $Z'$s can be very light, and can be searched for using precision flavor, astrophysics, and beam dump experiments.
0711.3998
Kenji Morita
Kenji Morita and Su Houng Lee
Critical behavior of charmonia across the phase transition: A QCD sum rule approach
18 pages, 21 figures, 2 figures are added and discussion on effect of dynamical quarks is extended. version to appear in Phys.Rev.C
Phys.Rev.C77:064904,2008
10.1103/PhysRevC.77.064904
null
hep-ph nucl-ex nucl-th
null
We investigate medium-induced change of mass and width of J/psi and eta_c across the phase transition in hot gluonic matter using QCD sum rules. In the QCD sum rule approach, the medium effect on heavy quarkonia is induced by the change of both scalar and twist-2 gluon condensates, whose temperature dependences are extracted from the lattice calculations of energy density and pressure. Although the stability of the operator product expansion side seems to break down at T > 1.06Tc for the vector channel and T>1.04Tc for the pseudoscalar channel, we find a sudden change of the spectral property across the critical temperature Tc, which originates from an equally rapid change of the scalar gluon condensate characterized by e-3p. By parameterizing the ground state of the spectral density by the Breit-Wigner form, we find that for both J/psi and eta_c, the masses suddenly decrease maximally by a few hundreds of MeV and the widths broaden to ~100 MeV slightly above Tc. Implications for recent and future heavy ion experiments are discussed. We also carry out a similar analysis for charmonia in nuclear matter, which could serve as a testing ground for observing the precursor phenomena of the QCD phase transition. We finally discuss the possibility of observing the mass shift at nuclear matter at the FAIR project at GSI.
[ { "created": "Mon, 26 Nov 2007 13:36:04 GMT", "version": "v1" }, { "created": "Wed, 14 May 2008 11:00:51 GMT", "version": "v2" } ]
2008-11-26
[ [ "Morita", "Kenji", "" ], [ "Lee", "Su Houng", "" ] ]
We investigate medium-induced change of mass and width of J/psi and eta_c across the phase transition in hot gluonic matter using QCD sum rules. In the QCD sum rule approach, the medium effect on heavy quarkonia is induced by the change of both scalar and twist-2 gluon condensates, whose temperature dependences are extracted from the lattice calculations of energy density and pressure. Although the stability of the operator product expansion side seems to break down at T > 1.06Tc for the vector channel and T>1.04Tc for the pseudoscalar channel, we find a sudden change of the spectral property across the critical temperature Tc, which originates from an equally rapid change of the scalar gluon condensate characterized by e-3p. By parameterizing the ground state of the spectral density by the Breit-Wigner form, we find that for both J/psi and eta_c, the masses suddenly decrease maximally by a few hundreds of MeV and the widths broaden to ~100 MeV slightly above Tc. Implications for recent and future heavy ion experiments are discussed. We also carry out a similar analysis for charmonia in nuclear matter, which could serve as a testing ground for observing the precursor phenomena of the QCD phase transition. We finally discuss the possibility of observing the mass shift at nuclear matter at the FAIR project at GSI.
hep-ph/9409211
Aaron Keith Grant
Tatsu Takeuchi, Aaron K. Grant and Jonathan L. Rosner
An Analysis of Non-Oblique Corrections to the $Z b \bar b$ Vertex
5 pages, with 4 PostScript figures
null
null
FERMILAB-CONF-94/279-T; EFI 94-44
hep-ph
null
We present a model--independent analysis of the $Z b \bar b$ vertex, with the aim of constraining contributions of new physics to the left- and right--handed couplings of the $b$. We find that the left--handed coupling of the $b$ is quite narrowly constrained by present data, but that the right--handed coupling is still largely unconstrained.
[ { "created": "Fri, 2 Sep 1994 03:57:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Takeuchi", "Tatsu", "" ], [ "Grant", "Aaron K.", "" ], [ "Rosner", "Jonathan L.", "" ] ]
We present a model--independent analysis of the $Z b \bar b$ vertex, with the aim of constraining contributions of new physics to the left- and right--handed couplings of the $b$. We find that the left--handed coupling of the $b$ is quite narrowly constrained by present data, but that the right--handed coupling is still largely unconstrained.
hep-ph/0204146
Francois Gelis
P. Aurenche (LAPTH, Annecy), F. Gelis (LPT, Orsay), H. Zaraket (Winnipeg Univ.)
A simple sum rule for the thermal gluon spectral function and applications
24 latex pages, 2 postscript figures
JHEP 0205:043,2002
10.1088/1126-6708/2002/05/043
LAPTH-909/02, LPT-ORSAY-02/27
hep-ph nucl-th
null
In this paper, we derive a simple sum rule satisfied by the gluon spectral function at finite temperature. This sum rule is useful in order to calculate exactly some integrals that appear frequently in the photon or dilepton production rate by a quark gluon plasma. Using this sum rule, we rederive simply some known results and obtain some new results that would be extremely difficult to justify otherwise. In particular, we derive an exact expression for the collision integral that appears in the calculation of the Landau-Pomeranchuk-Migdal effect.
[ { "created": "Fri, 12 Apr 2002 22:00:54 GMT", "version": "v1" } ]
2011-07-19
[ [ "Aurenche", "P.", "", "LAPTH, Annecy" ], [ "Gelis", "F.", "", "LPT, Orsay" ], [ "Zaraket", "H.", "", "Winnipeg Univ." ] ]
In this paper, we derive a simple sum rule satisfied by the gluon spectral function at finite temperature. This sum rule is useful in order to calculate exactly some integrals that appear frequently in the photon or dilepton production rate by a quark gluon plasma. Using this sum rule, we rederive simply some known results and obtain some new results that would be extremely difficult to justify otherwise. In particular, we derive an exact expression for the collision integral that appears in the calculation of the Landau-Pomeranchuk-Migdal effect.
hep-ph/9510309
Takeo Moroi
J. Hisano, T. Moroi, K. Tobe and M. Yamaguchi
Lepton-Flavor Violation via Right-Handed Neutrino Yukawa Couplings in Supersymmetric Standard Model
null
Phys.Rev. D53 (1996) 2442-2459
10.1103/PhysRevD.53.2442
null
hep-ph
null
Various lepton-flavor violating (LFV) processes in the supersymmetric standard model with right-handed neutrino supermultiplets are investigated in detail. It is shown that large LFV rates are obtained when $\tan \beta $ is large. In the case where the mixing matrix in the lepton sector has a similar structure as the Kobayashi-Maskawa matrix and the third-generation Yukawa coupling is as large as that of the top quark, the branching ratios can be as large as $Br(\mu\rightarrow e\gamma)\simeq 10^{-11}$ and $Br(\tau\rightarrow\mu\gamma)\simeq 10^{-7}$, which are within the reach of future experiments. If we assume a large mixing angle solution to the atmospheric neutrino problem, rate for the process $\tau\rightarrow\mu\gamma$ becomes larger. We also discuss the difference between our case and the case of the minimal $SU(5)$ grand unified theory.
[ { "created": "Mon, 16 Oct 1995 20:06:10 GMT", "version": "v1" } ]
2009-10-28
[ [ "Hisano", "J.", "" ], [ "Moroi", "T.", "" ], [ "Tobe", "K.", "" ], [ "Yamaguchi", "M.", "" ] ]
Various lepton-flavor violating (LFV) processes in the supersymmetric standard model with right-handed neutrino supermultiplets are investigated in detail. It is shown that large LFV rates are obtained when $\tan \beta $ is large. In the case where the mixing matrix in the lepton sector has a similar structure as the Kobayashi-Maskawa matrix and the third-generation Yukawa coupling is as large as that of the top quark, the branching ratios can be as large as $Br(\mu\rightarrow e\gamma)\simeq 10^{-11}$ and $Br(\tau\rightarrow\mu\gamma)\simeq 10^{-7}$, which are within the reach of future experiments. If we assume a large mixing angle solution to the atmospheric neutrino problem, rate for the process $\tau\rightarrow\mu\gamma$ becomes larger. We also discuss the difference between our case and the case of the minimal $SU(5)$ grand unified theory.
hep-ph/0512238
Andrzej Buras
Andrzej J. Buras
Photon Structure Functions: 1978 AND 2005
9 pages, 4 figures, to appear in Acta Physica Polonica, References added
ActaPhys.Polon.B37:609-618,2006
null
TUM-HEP-616/05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I describe the early days of the photon structure functions. In particular I discuss the parton model result of Walsh and Zerwas (1973), leading order QCD calculation of Witten (1976) and next-to-leading QCD calculation of Bardeen and myself (1978). A very brief summary of the progress made from 1978 until 2005 is also given.
[ { "created": "Mon, 19 Dec 2005 17:04:49 GMT", "version": "v1" }, { "created": "Thu, 29 Nov 2012 15:07:06 GMT", "version": "v2" } ]
2012-11-30
[ [ "Buras", "Andrzej J.", "" ] ]
I describe the early days of the photon structure functions. In particular I discuss the parton model result of Walsh and Zerwas (1973), leading order QCD calculation of Witten (1976) and next-to-leading QCD calculation of Bardeen and myself (1978). A very brief summary of the progress made from 1978 until 2005 is also given.
2309.14264
Simon Cl\'ery
Simon Cl\'ery
Gravitational production of matter and radiation during reheating
Contribution to the 34th Rencontres de Blois on Particle Physics and Cosmology (Blois 2023)
null
null
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present the production of matter and radiation during reheating after inflation, considering only gravitational interactions between the inflaton background and the other sectors. Processes considered are the following: i) the exchange of a graviton, $h_{\mu \nu}$, involved in the scattering of the inflaton or particles in the newly created radiation bath; ii) scattering of the inflaton background and particles in the radiation bath including the effects of non-minimal couplings to curvature of the Higgs boson and the inflaton. Requiring the existence of heavy right-handed neutrinos (RHN), I show that a minimal scenario utilizing only these "gravitational portals" is able to generate simultaneously the observed relic density of Dark Matter (DM), the baryon asymmetry through leptogenesis, as well as a sufficiently hot thermal bath after inflation, for generic models of large field inflation.
[ { "created": "Mon, 25 Sep 2023 16:23:07 GMT", "version": "v1" } ]
2023-09-26
[ [ "Cléry", "Simon", "" ] ]
I present the production of matter and radiation during reheating after inflation, considering only gravitational interactions between the inflaton background and the other sectors. Processes considered are the following: i) the exchange of a graviton, $h_{\mu \nu}$, involved in the scattering of the inflaton or particles in the newly created radiation bath; ii) scattering of the inflaton background and particles in the radiation bath including the effects of non-minimal couplings to curvature of the Higgs boson and the inflaton. Requiring the existence of heavy right-handed neutrinos (RHN), I show that a minimal scenario utilizing only these "gravitational portals" is able to generate simultaneously the observed relic density of Dark Matter (DM), the baryon asymmetry through leptogenesis, as well as a sufficiently hot thermal bath after inflation, for generic models of large field inflation.
hep-ph/9602409
Tord Riemann
Dima Bardin, Dietrich Lehner, Tord Riemann
Complete Initial State QED Corrections to Off-Shell Gauge Boson Pair Production in e+e- Annihilation
65 pages, 4 postscript figures, uses elsart.sty, amsfonts.sty, and epsfig.sty, full postscript available from http://www.ifh.de/~lehner/desy96-028.ps.gz
Nucl.Phys. B477 (1996) 27-58
10.1016/0550-3213(96)00354-9
DESY 96-028
hep-ph
null
We study Standard Model four-fermion production in e+ e- annihilation at LEP2 energies and above using a semi-analytical approach. We derive the complete QED initial state corrections (ISR) to the reactions e+e- -> ZZ -> $f_1\bar{f_1}f_2\bar{f_2}$ and e+e- -> W+W- -> ${\bar f}_1^u f_1^d f_2^u {\bar f}_2^d$ with $f_1\neq f_2$~and $f_i \neq e^\pm, \nu_e$. As compared to the well-known universal s-channel ISR, additional complexity arises due to non-universal, process-dependent ISR contributions from t- and u-channel fermion exchanges. The full set of formulae needed to perform numerical calculations is given together with samples of numerical results.
[ { "created": "Tue, 27 Feb 1996 16:04:49 GMT", "version": "v1" } ]
2009-10-28
[ [ "Bardin", "Dima", "" ], [ "Lehner", "Dietrich", "" ], [ "Riemann", "Tord", "" ] ]
We study Standard Model four-fermion production in e+ e- annihilation at LEP2 energies and above using a semi-analytical approach. We derive the complete QED initial state corrections (ISR) to the reactions e+e- -> ZZ -> $f_1\bar{f_1}f_2\bar{f_2}$ and e+e- -> W+W- -> ${\bar f}_1^u f_1^d f_2^u {\bar f}_2^d$ with $f_1\neq f_2$~and $f_i \neq e^\pm, \nu_e$. As compared to the well-known universal s-channel ISR, additional complexity arises due to non-universal, process-dependent ISR contributions from t- and u-channel fermion exchanges. The full set of formulae needed to perform numerical calculations is given together with samples of numerical results.
2312.17246
Emanuele Copello
Mathias Becker, Emanuele Copello, Julia Harz, Carlos Tamarit
Dark matter freeze-in from non-equilibrium QFT: towards a consistent treatment of thermal effects
67 pages, 15 figures, 4 appendices
null
null
MITP-23-085
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study thermal corrections to a model of real scalar dark matter interacting feebly with a SM fermion and a gauge-charged vector-like fermion. We employ the Closed-Time-Path (CTP) formalism for our calculation and go beyond previous works by including the full dependence on the relevant mass scales as opposed to using (non)relativistic approximations. In particular, we use 1PI-resummed propagators without relying on the Hard-Thermal-Loop approximation. We conduct our analysis at leading order in the loop expansion of the 2PI effective action and compare our findings to commonly used approximation schemes, including the aforementioned Hard-Thermal-Loop approximation and results obtained from solving Boltzmann equations using thermal masses as a regulator for $t$-channel divergences. We find that the Boltzmann approach deviates between $-10\%$ and $+30\%$ from our calculation, where the size and sign strongly depends on the mass splitting between the DM candidate and the gauge-charged parent. The HTL-approximated result is more precise for small gauge couplings and is percent level accurate for large mass splittings, whereas it overestimates the relic density up to $25 \%$ for small mass splittings. Tree-level propagators lead to underabundant DM as they do not account for scattering contributions and can deviate up to $-100\%$ from the 1PI-resummed result.
[ { "created": "Thu, 28 Dec 2023 18:59:41 GMT", "version": "v1" } ]
2023-12-29
[ [ "Becker", "Mathias", "" ], [ "Copello", "Emanuele", "" ], [ "Harz", "Julia", "" ], [ "Tamarit", "Carlos", "" ] ]
We study thermal corrections to a model of real scalar dark matter interacting feebly with a SM fermion and a gauge-charged vector-like fermion. We employ the Closed-Time-Path (CTP) formalism for our calculation and go beyond previous works by including the full dependence on the relevant mass scales as opposed to using (non)relativistic approximations. In particular, we use 1PI-resummed propagators without relying on the Hard-Thermal-Loop approximation. We conduct our analysis at leading order in the loop expansion of the 2PI effective action and compare our findings to commonly used approximation schemes, including the aforementioned Hard-Thermal-Loop approximation and results obtained from solving Boltzmann equations using thermal masses as a regulator for $t$-channel divergences. We find that the Boltzmann approach deviates between $-10\%$ and $+30\%$ from our calculation, where the size and sign strongly depends on the mass splitting between the DM candidate and the gauge-charged parent. The HTL-approximated result is more precise for small gauge couplings and is percent level accurate for large mass splittings, whereas it overestimates the relic density up to $25 \%$ for small mass splittings. Tree-level propagators lead to underabundant DM as they do not account for scattering contributions and can deviate up to $-100\%$ from the 1PI-resummed result.
1106.5619
Simona Stoica
S. Stoica, M. F. M. Lutz, O. Scholten
On kinematical constraints in fermion-antifermion systems
12 pages, 3 tables
null
10.1103/PhysRevD.84.125001
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the scattering of fermions off antifermions with spin 1/2 and 3/2. Starting from helicity partial-wave scattering amplitudes we derive transformations that eliminate all kinematical constraints. Such amplitudes are expected to satisfy partial-wave dispersion relations and therefore provide a suitable basis for data analysis and the construction of effective field theories. Our derivation relies on a decomposition of the various scattering amplitudes into suitable sets of invariant functions.
[ { "created": "Tue, 28 Jun 2011 10:27:31 GMT", "version": "v1" } ]
2015-05-28
[ [ "Stoica", "S.", "" ], [ "Lutz", "M. F. M.", "" ], [ "Scholten", "O.", "" ] ]
We consider the scattering of fermions off antifermions with spin 1/2 and 3/2. Starting from helicity partial-wave scattering amplitudes we derive transformations that eliminate all kinematical constraints. Such amplitudes are expected to satisfy partial-wave dispersion relations and therefore provide a suitable basis for data analysis and the construction of effective field theories. Our derivation relies on a decomposition of the various scattering amplitudes into suitable sets of invariant functions.
hep-ph/0406202
Tim Evans
T.S.Evans, M.Ivin
Testing an Optimised Expansion on Z_2 Lattice Models
47 pages, some figures in colour but will display fine in BW
null
null
Imperial/TP/3-04/15
hep-ph
null
We test an optimised hopping parameter expansion on various Z_2 lattice scalar field models: the Ising model, a spin-one model and lambda (phi)^4. We do this by studying the critical indices for a variety of optimisation criteria, in a range of dimensions and with various trial actions. We work up to seventh order, thus going well beyond previous studies. We demonstrate how to use numerical methods to generate the high order diagrams and their corresponding expressions. These are then used to calculate results numerically and, in the case of the Ising model, we obtain some analytic results. We highlight problems with several optimisation schemes and show for the best scheme that the critical exponents are consistent with mean field results to at least 8 significant figures. We conclude that in its present form, such optimised lattice expansions do not seem to be capturing the non-perturbative infra-red physics near the critical points of scalar models.
[ { "created": "Fri, 18 Jun 2004 12:26:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Evans", "T. S.", "" ], [ "Ivin", "M.", "" ] ]
We test an optimised hopping parameter expansion on various Z_2 lattice scalar field models: the Ising model, a spin-one model and lambda (phi)^4. We do this by studying the critical indices for a variety of optimisation criteria, in a range of dimensions and with various trial actions. We work up to seventh order, thus going well beyond previous studies. We demonstrate how to use numerical methods to generate the high order diagrams and their corresponding expressions. These are then used to calculate results numerically and, in the case of the Ising model, we obtain some analytic results. We highlight problems with several optimisation schemes and show for the best scheme that the critical exponents are consistent with mean field results to at least 8 significant figures. We conclude that in its present form, such optimised lattice expansions do not seem to be capturing the non-perturbative infra-red physics near the critical points of scalar models.
hep-ph/0503044
Gianluca Calcagni
Gianluca Calcagni
Braneworld cosmology and noncommutative inflation
10+158 pages, 31 omitted figures; PhD thesis, advisor Dr. L. Griguolo; v2-v3: references added. PACS numbers: 98.80.Cq, 04.50.+h, 98.70.Vc
null
null
null
hep-ph astro-ph gr-qc hep-th
null
In this work we develop the patch formalism, an approach providing a very simple and compact description of braneworld-motivated cosmologies with nonstandard effective Friedmann equations. In particular, the Hubble parameter is assumed to depend on some power of the brane energy density, H^2 \propto \rho^q. The high-energy limit of Randall-Sundrum (q=2) and Gauss-Bonnet (q=2/3) braneworlds are considered, during an accelerating era triggered by a single ordinary or tachyonic scalar field. The inflationary dynamics, solutions, and spectra are provided. Using the latest results from WMAP and other experiments for estimates of cosmological observables, it is shown that future data and missions can in principle discriminate between standard four-dimensional and braneworld scenarios. The issue of non-Gaussianity is also studied within nonlinear perturbation theory. The introduction of a fundamental energy scale reinforces these results. Several classes of noncommutative inflationary models are considered and their features analyzed in a number of ways and energy regimes. Finally, we establish dual relations between inflationary, cyclic/ekpyrotic and phantom cosmologies, as well as between scalar-driven and tachyon-driven cosmologies. The exact dualities relating the four-dimensional spectra are broken in favour of their braneworld counterparts. The dual solutions display new interesting features because of the modification of the effective Friedmann equation on the brane.
[ { "created": "Fri, 4 Mar 2005 11:37:08 GMT", "version": "v1" }, { "created": "Sun, 13 Mar 2005 21:09:24 GMT", "version": "v2" }, { "created": "Thu, 24 Mar 2005 21:23:58 GMT", "version": "v3" } ]
2007-05-23
[ [ "Calcagni", "Gianluca", "" ] ]
In this work we develop the patch formalism, an approach providing a very simple and compact description of braneworld-motivated cosmologies with nonstandard effective Friedmann equations. In particular, the Hubble parameter is assumed to depend on some power of the brane energy density, H^2 \propto \rho^q. The high-energy limit of Randall-Sundrum (q=2) and Gauss-Bonnet (q=2/3) braneworlds are considered, during an accelerating era triggered by a single ordinary or tachyonic scalar field. The inflationary dynamics, solutions, and spectra are provided. Using the latest results from WMAP and other experiments for estimates of cosmological observables, it is shown that future data and missions can in principle discriminate between standard four-dimensional and braneworld scenarios. The issue of non-Gaussianity is also studied within nonlinear perturbation theory. The introduction of a fundamental energy scale reinforces these results. Several classes of noncommutative inflationary models are considered and their features analyzed in a number of ways and energy regimes. Finally, we establish dual relations between inflationary, cyclic/ekpyrotic and phantom cosmologies, as well as between scalar-driven and tachyon-driven cosmologies. The exact dualities relating the four-dimensional spectra are broken in favour of their braneworld counterparts. The dual solutions display new interesting features because of the modification of the effective Friedmann equation on the brane.
hep-ph/9705328
D. R. T. Jones
P.M. Ferreira, I. Jack, D.R.T. Jones and C.G. North
$\beta$-functions in large-$N_f$ supersymmetric gauge theories
22 pages, tex, 7 figures. Uses harvmac and epsf
Nucl.Phys. B504 (1997) 108-126
10.1016/S0550-3213(97)00448-3
LTH 392
hep-ph
null
We present calculations of the leading and $O(1/N_f)$ terms in a large-$N_f$ expansion of the $\beta$-functions and anomalous dimensions for various supersymmetric gauge theories, including supersymmetric QCD. In the case of supersymmetric QCD, we show that our $O(1/N_f)$ approximation displays an infra-red fixed point in the conformal window $3N_c/2 < N_f < 3N_c$.
[ { "created": "Thu, 15 May 1997 17:00:26 GMT", "version": "v1" } ]
2009-10-30
[ [ "Ferreira", "P. M.", "" ], [ "Jack", "I.", "" ], [ "Jones", "D. R. T.", "" ], [ "North", "C. G.", "" ] ]
We present calculations of the leading and $O(1/N_f)$ terms in a large-$N_f$ expansion of the $\beta$-functions and anomalous dimensions for various supersymmetric gauge theories, including supersymmetric QCD. In the case of supersymmetric QCD, we show that our $O(1/N_f)$ approximation displays an infra-red fixed point in the conformal window $3N_c/2 < N_f < 3N_c$.
1703.03692
Andreas Trautner
Andreas Trautner
CP as a Symmetry of Symmetries
Talk given at DISCRETE 2016: Fifth Symposium on Prospects in the Physics of Discrete Symmetries, Warsaw, 28 Nov - 3 Dec, 2016, 10 pages
null
10.1088/1742-6596/873/1/012037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is explained that the Standard Model combined charge conjugation and parity transformation (CP) is a simultaneous complex conjugation outer automorphism transformation of gauge and space-time symmetries. Simple examples are given for the general concept of outer automorphisms ("symmetries of symmetries"), as well as for their possible actions on physical theories. It is highlighted that complex conjugation outer automorphisms do not, in general, exist for all symmetries. Examples are given for cases in which the physical CP transformation is violated as a consequence of requiring another symmetry. A toy model is illustrated in which CP is spontaneously violated in the broken phase of a continuous gauge symmetry, while an unbroken outer automorphism protects the topological vacuum angle at $\theta=0$.
[ { "created": "Fri, 10 Mar 2017 14:17:34 GMT", "version": "v1" } ]
2017-09-13
[ [ "Trautner", "Andreas", "" ] ]
It is explained that the Standard Model combined charge conjugation and parity transformation (CP) is a simultaneous complex conjugation outer automorphism transformation of gauge and space-time symmetries. Simple examples are given for the general concept of outer automorphisms ("symmetries of symmetries"), as well as for their possible actions on physical theories. It is highlighted that complex conjugation outer automorphisms do not, in general, exist for all symmetries. Examples are given for cases in which the physical CP transformation is violated as a consequence of requiring another symmetry. A toy model is illustrated in which CP is spontaneously violated in the broken phase of a continuous gauge symmetry, while an unbroken outer automorphism protects the topological vacuum angle at $\theta=0$.
0808.2118
A. V. Luchinsky
V. V. Braguta, A. K. Likhoded and A. V. Luchinsky
Study of exclusive processes e^+ e^- \to VP
10 pages, 2 tables, 6 figures; minor changes; article accepted to publication is Phys. Rev. D
Phys.Rev.D78:074032,2008
10.1103/PhysRevD.78.074032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper is devoted to consideration of the hard exclusive processes $e^+e^- \to VP$, where $V=\rho,\phi; P=\eta,\eta'$. Experimental measurement of the cross section of the process $e^+ e^- \to \phi\eta$ at BaBar collaboration at large center mass energy $\sqrt s=10.6$ GeV and some low energy experimental data $\sqrt s \sim 2-4$ GeV give us the possibility to study the cross section in the broad energy region. As the result, we have determined the asymptotic behavior of the cross section of $e^+ e^- \to \phi\eta$ in the limit $s \to \infty$, which is in agreement with perturbative QCD prediction. Assuming that the same asymptotic behavior is valid for the other processes under consideration and using low energy experimental data we have predicted the cross sections of these processes at energies $\sqrt s=3.67,~10.6$ GeV. In addition, we have calculated the cross sections of these processes at the same energies within perturbative QCD. Our results are in agreement with available experimental data.
[ { "created": "Fri, 15 Aug 2008 09:37:01 GMT", "version": "v1" }, { "created": "Fri, 17 Oct 2008 08:31:35 GMT", "version": "v2" } ]
2008-11-26
[ [ "Braguta", "V. V.", "" ], [ "Likhoded", "A. K.", "" ], [ "Luchinsky", "A. V.", "" ] ]
This paper is devoted to consideration of the hard exclusive processes $e^+e^- \to VP$, where $V=\rho,\phi; P=\eta,\eta'$. Experimental measurement of the cross section of the process $e^+ e^- \to \phi\eta$ at BaBar collaboration at large center mass energy $\sqrt s=10.6$ GeV and some low energy experimental data $\sqrt s \sim 2-4$ GeV give us the possibility to study the cross section in the broad energy region. As the result, we have determined the asymptotic behavior of the cross section of $e^+ e^- \to \phi\eta$ in the limit $s \to \infty$, which is in agreement with perturbative QCD prediction. Assuming that the same asymptotic behavior is valid for the other processes under consideration and using low energy experimental data we have predicted the cross sections of these processes at energies $\sqrt s=3.67,~10.6$ GeV. In addition, we have calculated the cross sections of these processes at the same energies within perturbative QCD. Our results are in agreement with available experimental data.
hep-ph/0111232
Tancredi Carli
Tancredi Carli
Small-x QCD Effects in Particle Collisions at High Energies
Invited talk at the XX. Int. Sym. on Lepton and Photon Interactions at High Energies, Rome, Italy, July 2001
Int.J.Mod.Phys.A17:3185-3203,2002
10.1142/S0217751X02012685
null
hep-ph
null
Recent theoretical developments to calculate cross sections of hadronic objects in the high energy limit are summarised and experimental attempts to establish the need for new QCD effects connected with a resummation of small hadron momentum fractions x are reviewed. The relation between small-$x$ parton dynamics and the phenomenon of diffraction is briefly out-lined. In addition, a search for a novel, non-perturbative QCD effect, the production of QCD instanton induced events, is presented.
[ { "created": "Mon, 19 Nov 2001 19:38:46 GMT", "version": "v1" }, { "created": "Wed, 5 Dec 2001 18:23:16 GMT", "version": "v2" } ]
2011-01-25
[ [ "Carli", "Tancredi", "" ] ]
Recent theoretical developments to calculate cross sections of hadronic objects in the high energy limit are summarised and experimental attempts to establish the need for new QCD effects connected with a resummation of small hadron momentum fractions x are reviewed. The relation between small-$x$ parton dynamics and the phenomenon of diffraction is briefly out-lined. In addition, a search for a novel, non-perturbative QCD effect, the production of QCD instanton induced events, is presented.
0810.3624
Nazario Tantalo
N. Tantalo
Heavy-light meson's physics in Lattice QCD
talk at 34th International Conference on High Energy Physics, Philadelphia, USA, 2008. 4 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possibility of revealing new physics by studying the flavor sector of the Standard Model strongly depends upon the accuracy that will be achieved in (near) future lattice QCD calculations and, in particular, on heavy-light meson's observables. In turn, handling with heavy-light mesons on the lattice is a challenging problem, because of the presence of two largely separated energy scales, and at present it is impossible to extract matrix elements involving B mesons in external states without recurring to some approximation. In this note I give a fast overview of some of the methods that have been devised to handle such kind of problems, emphasizing those based on finite volume techniques, and briefly discuss some recent results obtained by their application.
[ { "created": "Mon, 20 Oct 2008 18:26:22 GMT", "version": "v1" } ]
2008-10-21
[ [ "Tantalo", "N.", "" ] ]
The possibility of revealing new physics by studying the flavor sector of the Standard Model strongly depends upon the accuracy that will be achieved in (near) future lattice QCD calculations and, in particular, on heavy-light meson's observables. In turn, handling with heavy-light mesons on the lattice is a challenging problem, because of the presence of two largely separated energy scales, and at present it is impossible to extract matrix elements involving B mesons in external states without recurring to some approximation. In this note I give a fast overview of some of the methods that have been devised to handle such kind of problems, emphasizing those based on finite volume techniques, and briefly discuss some recent results obtained by their application.
hep-ph/0603019
Tim Gershon
G.Cavoto, R.Fleischer, T.Gershon, A.Soni, K.Abe, J.Albert, D.Asner, D.Atwood, M.Bruinsma, S.Ganzhur, B.Iyutin, Y.Y.Keum, T.Mannel, K.Miyabayashi, N.Neri, A.A.Petrov, M.Pierini, F.Polci, M.Rama, F.Ronga, L.Silvestrini, A.Stocchi, M.H.Schune, V.Sordini, M.Verderi, C.Voena, G.Wilkinson, J.Zupan
Angles from $B$ Decays with Charm
62 pages, 55 figures. Proceedings of the CKM 2005 Workshop (WG5), UC San Diego, 15-18 March 2005
null
null
null
hep-ph hep-ex
null
Proceedings of the CKM 2005 Workshop (WG5), UC San Diego, 15-18 March 2005.
[ { "created": "Thu, 2 Mar 2006 18:32:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cavoto", "G.", "" ], [ "Fleischer", "R.", "" ], [ "Gershon", "T.", "" ], [ "Soni", "A.", "" ], [ "Abe", "K.", "" ], [ "Albert", "J.", "" ], [ "Asner", "D.", "" ], [ "Atwood", "D.", "" ], ...
Proceedings of the CKM 2005 Workshop (WG5), UC San Diego, 15-18 March 2005.
1912.09341
Basem Mahmoud El-Menoufi
Luke Arpino, Andrea Banfi and Basem Kamal El-Menoufi
Near-to-planar three-jet events at NNLL accuracy
47 pages, 9 figures. Added references and amended acknowledgements
null
10.1007/JHEP07(2020)171
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the ARES method for next-to-next-to-leading-logarithmic (NNLL) QCD resummations to three-jet event shapes in $e^+ e^-$ collisions in the near-to-planar limit. In particular, we define a NNLL radiator for three hard emitters, and discuss new features of NNLL corrections arising specifically in this case. As an example, we present predictions for the $D$-parameter, matched to exact NLO. After inclusion of hadronisation corrections in the dispersive approach, we compare our predictions with LEP1 data.
[ { "created": "Thu, 19 Dec 2019 16:23:59 GMT", "version": "v1" }, { "created": "Mon, 30 Dec 2019 13:11:03 GMT", "version": "v2" } ]
2020-08-26
[ [ "Arpino", "Luke", "" ], [ "Banfi", "Andrea", "" ], [ "El-Menoufi", "Basem Kamal", "" ] ]
We extend the ARES method for next-to-next-to-leading-logarithmic (NNLL) QCD resummations to three-jet event shapes in $e^+ e^-$ collisions in the near-to-planar limit. In particular, we define a NNLL radiator for three hard emitters, and discuss new features of NNLL corrections arising specifically in this case. As an example, we present predictions for the $D$-parameter, matched to exact NLO. After inclusion of hadronisation corrections in the dispersive approach, we compare our predictions with LEP1 data.
1010.4310
Ralf Ulrich
Ralf Ulrich, Ralph Engel, Michael Unger
Hadronic Multiparticle Production at Ultra-High Energies and Extensive Air Showers
submitted to PRD
Phys.Rev.D83:054026,2011
10.1103/PhysRevD.83.054026
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Studies of the nature of cosmic ray particles at the highest energies are based on the measurement of extensive air showers. Most cosmic ray properties can therefore only be obtained from the interpretation of air shower data and are thus depending on predictions of hadronic interaction models at ultra-high energies. We discuss different scenarios of model extrapolations from accelerator data to air shower energies and investigate their impact on the corresponding air shower predictions. To explore the effect of different extrapolations by hadronic interaction models we developed an ad hoc model. This ad hoc model is based on the modification of the output of standard hadronic interaction event generators within the air shower simulation process and allows us to study the impact of changing interaction features on the air shower development. In a systematic study we demonstrate the resulting changes of important air shower observables and also discuss them in terms of the predictions of the Heitler model of air shower cascades. It is found that the results of our ad hoc modifications are, to a large extend, independent of the choice of the underlying hadronic interaction model.
[ { "created": "Wed, 20 Oct 2010 20:12:38 GMT", "version": "v1" } ]
2011-03-31
[ [ "Ulrich", "Ralf", "" ], [ "Engel", "Ralph", "" ], [ "Unger", "Michael", "" ] ]
Studies of the nature of cosmic ray particles at the highest energies are based on the measurement of extensive air showers. Most cosmic ray properties can therefore only be obtained from the interpretation of air shower data and are thus depending on predictions of hadronic interaction models at ultra-high energies. We discuss different scenarios of model extrapolations from accelerator data to air shower energies and investigate their impact on the corresponding air shower predictions. To explore the effect of different extrapolations by hadronic interaction models we developed an ad hoc model. This ad hoc model is based on the modification of the output of standard hadronic interaction event generators within the air shower simulation process and allows us to study the impact of changing interaction features on the air shower development. In a systematic study we demonstrate the resulting changes of important air shower observables and also discuss them in terms of the predictions of the Heitler model of air shower cascades. It is found that the results of our ad hoc modifications are, to a large extend, independent of the choice of the underlying hadronic interaction model.
1512.03852
Pilar Coloma
Pilar Coloma, Bogdan A. Dobrescu, Claudia Frugiuele and Roni Harnik
Dark matter beams at LBNF
26 pages, 7 figures
null
10.1007/JHEP04(2016)047
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High-intensity neutrino beam facilities may produce a beam of light dark matter when protons strike the target. Searches for such a dark matter beam using its scattering in a nearby detector must overcome the large neutrino background. We characterize the spatial and energy distributions of the dark matter and neutrino beams, focusing on their differences to enhance the sensitivity to dark matter. We find that a dark matter beam produced by a $Z'$ boson in the GeV mass range is both broader and more energetic than the neutrino beam. The reach for dark matter is maximized for a detector sensitive to hard neutral-current scatterings, placed at a sizable angle off the neutrino beam axis. In the case of the Long-Baseline Neutrino Facility (LBNF), a detector placed at roughly 6 degrees off axis and at a distance of about 200 m from the target would be sensitive to $Z'$ couplings as low as 0.05. This search can proceed symbiotically with neutrino measurements. We also show that the MiniBooNE and MicroBooNE detectors, which are on Fermilab's Booster beamline, happen to be at an optimal angle from the NuMI beam and could perform searches with existing data. This illustrates potential synergies between LBNF and the short-baseline neutrino program if the detectors are positioned appropriately.
[ { "created": "Sat, 12 Dec 2015 00:32:03 GMT", "version": "v1" } ]
2016-05-04
[ [ "Coloma", "Pilar", "" ], [ "Dobrescu", "Bogdan A.", "" ], [ "Frugiuele", "Claudia", "" ], [ "Harnik", "Roni", "" ] ]
High-intensity neutrino beam facilities may produce a beam of light dark matter when protons strike the target. Searches for such a dark matter beam using its scattering in a nearby detector must overcome the large neutrino background. We characterize the spatial and energy distributions of the dark matter and neutrino beams, focusing on their differences to enhance the sensitivity to dark matter. We find that a dark matter beam produced by a $Z'$ boson in the GeV mass range is both broader and more energetic than the neutrino beam. The reach for dark matter is maximized for a detector sensitive to hard neutral-current scatterings, placed at a sizable angle off the neutrino beam axis. In the case of the Long-Baseline Neutrino Facility (LBNF), a detector placed at roughly 6 degrees off axis and at a distance of about 200 m from the target would be sensitive to $Z'$ couplings as low as 0.05. This search can proceed symbiotically with neutrino measurements. We also show that the MiniBooNE and MicroBooNE detectors, which are on Fermilab's Booster beamline, happen to be at an optimal angle from the NuMI beam and could perform searches with existing data. This illustrates potential synergies between LBNF and the short-baseline neutrino program if the detectors are positioned appropriately.
hep-ph/0306185
Eef van Beveren
Eef van Beveren and George Rupp
Threshold behavior of scattering poles
13 pages plain LaTeX, 7 figures included; Talk given at the High-Energy Physics Workshop, Scalar Mesons: an Interesting Puzzle for QCD, May 16 - 18, 2003, SUNY Institute of Technology, Utica (NY)
AIPConf.Proc.688:88-98,2003
10.1063/1.1632197
null
hep-ph
null
The results of a model for meson-meson scattering are studied. The model is shown to be capable of on the one hand reproducing the scattering data, while on the other hand a quark-antiquark confinement spectrum can be determined. It is concluded that adopting the model's formulation of the transition matrix elements for data analysis, it may serve as a link between experiment and quenched lattice calculations.
[ { "created": "Fri, 20 Jun 2003 11:53:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "van Beveren", "Eef", "" ], [ "Rupp", "George", "" ] ]
The results of a model for meson-meson scattering are studied. The model is shown to be capable of on the one hand reproducing the scattering data, while on the other hand a quark-antiquark confinement spectrum can be determined. It is concluded that adopting the model's formulation of the transition matrix elements for data analysis, it may serve as a link between experiment and quenched lattice calculations.
hep-ph/0212371
Nefediev Alexei
A.V.Nefediev (IST, Lisbon and ITEP, Moscow), J.E.F.T.Ribeiro (IST, Lisbon)
Field theory description of vacuum replicas
RevTeX4, 23 pages, 4 Postscript figures, uses epsfig.sty, to appear in Phys.Rev.D
Phys.Rev. D67 (2003) 034028
10.1103/PhysRevD.67.034028
null
hep-ph
null
In this paper we develop a systematic quantum field theory based approach to the vacuum replica recently found to exist in effective low energy models in hadronic physics. A local operator creating the replica state is constructed explicitly. We show that a new effective quark-quark force arises in result of replica existence. Phenomenological implications of such a force are also briefly discussed.
[ { "created": "Thu, 26 Dec 2002 12:08:39 GMT", "version": "v1" } ]
2009-11-07
[ [ "Nefediev", "A. V.", "", "IST, Lisbon and ITEP, Moscow" ], [ "Ribeiro", "J. E. F. T.", "", "IST,\n Lisbon" ] ]
In this paper we develop a systematic quantum field theory based approach to the vacuum replica recently found to exist in effective low energy models in hadronic physics. A local operator creating the replica state is constructed explicitly. We show that a new effective quark-quark force arises in result of replica existence. Phenomenological implications of such a force are also briefly discussed.
0905.1534
Ming-Yang Huang
Xin-Heng Guo, Ming-Yang Huang, and Bing-Lin Young
Supernova Neutrinos Detection On Earth
5 pages, 2 figures
Chin. Phys. C 34: 257, 2010
10.1088/1674-1137/34/2/020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we first discuss the detection of supernova neutrino on Earth. Then we propose a possible method to acquire information about $\theta_{13}$ smaller than $1.5^\circ$ by detecting the ratio of the event numbers of different flavor supernova neutrinos. Such an sensitivity cannot yet be achieved by the Daya Bay reactor neutrino experiment.
[ { "created": "Mon, 11 May 2009 07:07:01 GMT", "version": "v1" }, { "created": "Tue, 12 May 2009 01:09:58 GMT", "version": "v2" } ]
2010-01-22
[ [ "Guo", "Xin-Heng", "" ], [ "Huang", "Ming-Yang", "" ], [ "Young", "Bing-Lin", "" ] ]
In this paper, we first discuss the detection of supernova neutrino on Earth. Then we propose a possible method to acquire information about $\theta_{13}$ smaller than $1.5^\circ$ by detecting the ratio of the event numbers of different flavor supernova neutrinos. Such an sensitivity cannot yet be achieved by the Daya Bay reactor neutrino experiment.