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1112.5057
Irene Niessen
Wim Beenakker, Silja Brensing, Michael Kr\"amer, Anna Kulesza, Eric Laenen and Irene Niessen
NNLL resummation for squark-antisquark production
8 pages, 5 Figures; to appear in the proceedings of the "10th International Symposium on Radiative Corrections" (RADCOR2011)
null
null
DESY 11-254
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on the resummation of soft-gluon emissions for squark-antisquark production at next-to-next-to-leading-logarithmic (NNLL) accuracy. We will put particular emphasis on the one loop hard matching coefficients required to perform the resummation. Furthermore we will discuss the numerical effect of the different ingredients in the corrections. We find a significant reduction in the scale uncertainty and a considerable increase in the prediction of the total cross section at the central scale. Compared to the next-to-leading order prediction, the corrections increase the cross section by up to 30% for 1.5 TeV squarks at a centre-of-mass energy of 7 TeV at the LHC.
[ { "created": "Wed, 21 Dec 2011 15:26:34 GMT", "version": "v1" } ]
2011-12-22
[ [ "Beenakker", "Wim", "" ], [ "Brensing", "Silja", "" ], [ "Krämer", "Michael", "" ], [ "Kulesza", "Anna", "" ], [ "Laenen", "Eric", "" ], [ "Niessen", "Irene", "" ] ]
We report on the resummation of soft-gluon emissions for squark-antisquark production at next-to-next-to-leading-logarithmic (NNLL) accuracy. We will put particular emphasis on the one loop hard matching coefficients required to perform the resummation. Furthermore we will discuss the numerical effect of the different ingredients in the corrections. We find a significant reduction in the scale uncertainty and a considerable increase in the prediction of the total cross section at the central scale. Compared to the next-to-leading order prediction, the corrections increase the cross section by up to 30% for 1.5 TeV squarks at a centre-of-mass energy of 7 TeV at the LHC.
hep-ph/0108011
Jiro Kodaira
H. Kawamura, Y. Kiyo, J. Kodaira and K. Morii
Revisiting W gamma production at RHIC
14 pages, 15 Postscript figures
Prog.Theor.Phys. 107 (2002) 125-137
10.1143/PTP.107.125
DESY 01-098, HUPD-0107, TU-627
hep-ph
null
We discuss W gamma production in polarized p p collisions at RHIC energy. We point out that the RHIC collider has two advantages over other hadron colliders to measure the characteristic feature of W gamma production: (1) the RHIC energy is not so high and (2) the polarized beams are available. We calculate the tree level cross section for W gamma production using a generic spin basis for W and discuss both the angular dependence and spin correlation.
[ { "created": "Thu, 2 Aug 2001 02:35:10 GMT", "version": "v1" } ]
2009-11-07
[ [ "Kawamura", "H.", "" ], [ "Kiyo", "Y.", "" ], [ "Kodaira", "J.", "" ], [ "Morii", "K.", "" ] ]
We discuss W gamma production in polarized p p collisions at RHIC energy. We point out that the RHIC collider has two advantages over other hadron colliders to measure the characteristic feature of W gamma production: (1) the RHIC energy is not so high and (2) the polarized beams are available. We calculate the tree level cross section for W gamma production using a generic spin basis for W and discuss both the angular dependence and spin correlation.
hep-ph/0006048
null
P. K. Panda, T. Csorgo, Y. Hama, G. Krein, Sandra S. Padula
Squeezed Fermions at Relativistic Heavy Ion Colliders
LaTeX, ReVTeX 12 pages, uses epsf.sty, 2 eps figures, improved presentation
Phys.Lett. B512 (2001) 49-56
10.1016/S0370-2693(01)00585-8
CU - TP -970 / 2000
hep-ph nucl-ex nucl-th
null
Large back-to-back correlations of observable fermion -- anti-fermion pairs are predicted to appear, if the mass of the fermions is modified in a thermalized medium. The back-to-back correlations of protons and anti-protons are experimentally observable in ultra-relativistic heavy ion collisions, similarly to the Andreev reflection of electrons off the boundary of a superconductor. While quantum statistics suppresses the probability of observing pairs of fermions with nearby momenta, the fermionic back-to-back correlations are positive and of similar strength to bosonic back-to-back correlations.
[ { "created": "Mon, 5 Jun 2000 19:34:36 GMT", "version": "v1" }, { "created": "Fri, 18 Aug 2000 21:31:59 GMT", "version": "v2" }, { "created": "Thu, 21 Dec 2000 21:29:47 GMT", "version": "v3" }, { "created": "Mon, 19 Mar 2001 18:02:20 GMT", "version": "v4" } ]
2009-10-31
[ [ "Panda", "P. K.", "" ], [ "Csorgo", "T.", "" ], [ "Hama", "Y.", "" ], [ "Krein", "G.", "" ], [ "Padula", "Sandra S.", "" ] ]
Large back-to-back correlations of observable fermion -- anti-fermion pairs are predicted to appear, if the mass of the fermions is modified in a thermalized medium. The back-to-back correlations of protons and anti-protons are experimentally observable in ultra-relativistic heavy ion collisions, similarly to the Andreev reflection of electrons off the boundary of a superconductor. While quantum statistics suppresses the probability of observing pairs of fermions with nearby momenta, the fermionic back-to-back correlations are positive and of similar strength to bosonic back-to-back correlations.
2011.06537
Mahdi Torabian
Mahdi Torabian
Electroweak Vacuum Stability and the Higgs Field Relaxation via Gravitational Effects
7 pages, 3 figures, This article is an expanded and a published version of results initially reported in arXiv:1410.1744
Class.Quant.Grav. 37 (2020) 6, 065009
10.1088/1361-6382/ab6997
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The measured values of the Standard Model (SM) parameters favors a shallow metastable electroweak (EW) vacuum surrounded by a deep global AdS or a runaway Minkowski minimum. Furthermore, fine-tuning is the only explanation for the Higgs relaxing in its present local minimum. In this paper, assuming no new physics beyond the SM, we study the universal effect of gravity on the Higgs dynamics in the early universe. A generic two-parameter model is considered in which the Higgs is non-minimally coupled to a higher-curvature theory of gravity. The coupling between the Higgs field and the Weyl field in the Einstein frame has genuine predictions. In a broad region in the parameter space, the effective Higgs mass is large and it initially takes over through fast oscillations. This epoch is followed by the Weyl field slowly rolling a plateau-like potential. This framework generically predicts that the Higgs self-coupling in the EW vacuum is enhanced, compared to the SM predictions, through couplings to the gravity sector. Moreover, when the Higgs is settled in the EW vacuum, all other scalar flat directions would be lifted via gravitational effects mediated by the Weyl field.
[ { "created": "Thu, 12 Nov 2020 17:52:08 GMT", "version": "v1" } ]
2020-11-13
[ [ "Torabian", "Mahdi", "" ] ]
The measured values of the Standard Model (SM) parameters favors a shallow metastable electroweak (EW) vacuum surrounded by a deep global AdS or a runaway Minkowski minimum. Furthermore, fine-tuning is the only explanation for the Higgs relaxing in its present local minimum. In this paper, assuming no new physics beyond the SM, we study the universal effect of gravity on the Higgs dynamics in the early universe. A generic two-parameter model is considered in which the Higgs is non-minimally coupled to a higher-curvature theory of gravity. The coupling between the Higgs field and the Weyl field in the Einstein frame has genuine predictions. In a broad region in the parameter space, the effective Higgs mass is large and it initially takes over through fast oscillations. This epoch is followed by the Weyl field slowly rolling a plateau-like potential. This framework generically predicts that the Higgs self-coupling in the EW vacuum is enhanced, compared to the SM predictions, through couplings to the gravity sector. Moreover, when the Higgs is settled in the EW vacuum, all other scalar flat directions would be lifted via gravitational effects mediated by the Weyl field.
2302.01353
Janusz Rosiek
A. Dedes, J. Rosiek, M. Ryczkowski, K. Suxho, L. Trifyllis
SmeftFR v3 -- Feynman rules generator for the Standard Model Effective Field Theory
51 pages, version accepted for publication in Computer Physics Communications. arXiv admin note: substantial text overlap with arXiv:1904.03204
Comput.Phys.Commun. 294 (2024) 108943
10.1016/j.cpc.2023.108943
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
We present version 3 of SmeftFR, a Mathematica package designed to generate the Feynman rules for the Standard Model Effective Field Theory (SMEFT) including the complete set of gauge invariant operators up to dimension-6 and the complete set of bosonic operators of dimension-8. Feynman rules are generated with the use of FeynRules package, directly in the physical (mass eigenstates) basis for all fields. The complete set of interaction vertices can be derived, including all or any chosen subset of SMEFT operators. As an option, the user can also choose preferred gauge fixing, generating Feynman rules in unitary or $R_\xi$-gauges. The novel feature in version-3 of SmeftFR is its ability to calculate SMEFT interactions consistently up to dimension-8 in EFT expansion (including quadratic dimension-6 terms) and express the vertices directly in terms of user-defined set of input-parameters. The derived Lagrangian in the mass basis can be exported in various formats supported by FeynRules, such as UFO, FeynArts etc. Initialisation of numerical values of Wilson coefficients of higher dimension operators is interfaced to WCxf format. The package also includes a dedicated Latex generator allowing to print the result in clear human-readable form. The SmeftFR v3 is publicly available at www.fuw.edu.pl/smeft.
[ { "created": "Thu, 2 Feb 2023 19:00:02 GMT", "version": "v1" }, { "created": "Fri, 13 Oct 2023 17:39:49 GMT", "version": "v2" } ]
2023-10-16
[ [ "Dedes", "A.", "" ], [ "Rosiek", "J.", "" ], [ "Ryczkowski", "M.", "" ], [ "Suxho", "K.", "" ], [ "Trifyllis", "L.", "" ] ]
We present version 3 of SmeftFR, a Mathematica package designed to generate the Feynman rules for the Standard Model Effective Field Theory (SMEFT) including the complete set of gauge invariant operators up to dimension-6 and the complete set of bosonic operators of dimension-8. Feynman rules are generated with the use of FeynRules package, directly in the physical (mass eigenstates) basis for all fields. The complete set of interaction vertices can be derived, including all or any chosen subset of SMEFT operators. As an option, the user can also choose preferred gauge fixing, generating Feynman rules in unitary or $R_\xi$-gauges. The novel feature in version-3 of SmeftFR is its ability to calculate SMEFT interactions consistently up to dimension-8 in EFT expansion (including quadratic dimension-6 terms) and express the vertices directly in terms of user-defined set of input-parameters. The derived Lagrangian in the mass basis can be exported in various formats supported by FeynRules, such as UFO, FeynArts etc. Initialisation of numerical values of Wilson coefficients of higher dimension operators is interfaced to WCxf format. The package also includes a dedicated Latex generator allowing to print the result in clear human-readable form. The SmeftFR v3 is publicly available at www.fuw.edu.pl/smeft.
1408.1708
Wally Melnitchouk
P. Jimenez-Delgado, T. J. Hobbs, J. T. Londergan, W. Melnitchouk
New limits on intrinsic charm in the nucleon from global analysis of parton distributions
5 pages, 3 figures; discussion of charm thresholds included; to appear in PRL
Phys. Rev. Lett. 114, 082002 (2015)
10.1103/PhysRevLett.114.082002
JLAB-THY-14-1930
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new global QCD analysis of parton distribution functions, allowing for possible intrinsic charm (IC) contributions in the nucleon inspired by light-front models. The analysis makes use of the full range of available high-energy scattering data for Q^2 > 1 GeV^2 and W^2 > 3.5 GeV^2, including fixed-target proton and deuteron cross sections at lower energies that were excluded in previous global analyses. The expanded data set places more stringent constraints on the momentum carried by IC, with <x>_IC at most 0.5% (corresponding to an IC normalization of ~ 1%) at the 4-sigma level for Delta chi^2 = 1. We also critically assess the impact of older EMC measurements of F_2c at large x, which favor a nonzero IC, but with very large chi^2 values.
[ { "created": "Thu, 7 Aug 2014 20:36:53 GMT", "version": "v1" }, { "created": "Thu, 29 Jan 2015 20:38:08 GMT", "version": "v2" } ]
2015-03-05
[ [ "Jimenez-Delgado", "P.", "" ], [ "Hobbs", "T. J.", "" ], [ "Londergan", "J. T.", "" ], [ "Melnitchouk", "W.", "" ] ]
We present a new global QCD analysis of parton distribution functions, allowing for possible intrinsic charm (IC) contributions in the nucleon inspired by light-front models. The analysis makes use of the full range of available high-energy scattering data for Q^2 > 1 GeV^2 and W^2 > 3.5 GeV^2, including fixed-target proton and deuteron cross sections at lower energies that were excluded in previous global analyses. The expanded data set places more stringent constraints on the momentum carried by IC, with <x>_IC at most 0.5% (corresponding to an IC normalization of ~ 1%) at the 4-sigma level for Delta chi^2 = 1. We also critically assess the impact of older EMC measurements of F_2c at large x, which favor a nonzero IC, but with very large chi^2 values.
1204.4458
Pavel Fileviez Perez
Jonathan M. Arnold (Caltech), Pavel Fileviez Perez (CCPP, NYU), Bartosz Fornal (Caltech), Sogee Spinner (SISSA)
On Higgs Decays, Baryon Number Violation, and SUSY at the LHC
null
Phys. Rev. D 85, 115024 (2012)
10.1103/PhysRevD.85.115024
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Baryon number violating interactions could modify the signatures of supersymmetric models at the Large Hadron Collider. In this article we investigate the predictions for the Higgs mass and the Higgs decays in a simple extension of the minimal supersymmetric standard model where the local baryon and lepton numbers are spontaneously broken at the TeV scale. This theory predicts baryon number violation at the low scale which can change the current LHC bounds on the supersymmetric spectrum. Using the ATLAS and CMS bounds on the Higgs mass we show the constraints on the sfermion masses, and show the subsequent predictions for the radiative Higgs decays. We found that the Higgs decay into two photons is suppressed due to the existence of new light leptons. In this theory the stops can be very light in agreement with all experimental bounds and we make a brief discussion of the possible signals at the LHC.
[ { "created": "Thu, 19 Apr 2012 20:04:02 GMT", "version": "v1" } ]
2012-07-04
[ [ "Arnold", "Jonathan M.", "", "Caltech" ], [ "Perez", "Pavel Fileviez", "", "CCPP, NYU" ], [ "Fornal", "Bartosz", "", "Caltech" ], [ "Spinner", "Sogee", "", "SISSA" ] ]
Baryon number violating interactions could modify the signatures of supersymmetric models at the Large Hadron Collider. In this article we investigate the predictions for the Higgs mass and the Higgs decays in a simple extension of the minimal supersymmetric standard model where the local baryon and lepton numbers are spontaneously broken at the TeV scale. This theory predicts baryon number violation at the low scale which can change the current LHC bounds on the supersymmetric spectrum. Using the ATLAS and CMS bounds on the Higgs mass we show the constraints on the sfermion masses, and show the subsequent predictions for the radiative Higgs decays. We found that the Higgs decay into two photons is suppressed due to the existence of new light leptons. In this theory the stops can be very light in agreement with all experimental bounds and we make a brief discussion of the possible signals at the LHC.
2103.12082
Mustafa Amin
Mustafa A. Amin, Andrew J. Long, Zong-Gang Mou, Paul Saffin
Dipole Radiation and Beyond from Axion Stars in Electromagnetic Fields
12 figures, 28 pages + 1 Appendix
null
10.1007/JHEP06(2021)182
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the production of photons from coherently oscillating, spatially localized clumps of axionic fields (oscillons and axion stars) in the presence of external electromagnetic fields. We delineate different qualitative behaviour of the photon luminosity in terms of an effective dimensionless coupling parameter constructed out of the axion-photon coupling, and field amplitude, oscillation frequency and radius of the axion star. For small values of this dimensionless coupling, we provide a general analytic formula for the dipole radiation field and the photon luminosity per solid angle, including a strong dependence on the radius of the configuration. For moderate to large coupling, we report on a non-monotonic behavior of the luminosity with the coupling strength in the presence of external magnetic fields. After an initial rise in luminosity with the coupling strength, we see a suppression (by an order of magnitude or more compared to the dipole radiation approximation) at moderately large coupling. At sufficiently large coupling, we find a transition to a regime of exponential growth of the luminosity due to parametric resonance. We carry out 3+1 dimensional lattice simulations of axion electrodynamics, at small and large coupling, including non-perturbative effects of parametric resonance as well as backreaction effects when necessary. We also discuss medium (plasma) effects that lead to resonant axion to photon conversion, relevance of the coherence of the soliton, and implications of our results in astrophysical and cosmological settings.
[ { "created": "Mon, 22 Mar 2021 18:00:04 GMT", "version": "v1" } ]
2021-07-14
[ [ "Amin", "Mustafa A.", "" ], [ "Long", "Andrew J.", "" ], [ "Mou", "Zong-Gang", "" ], [ "Saffin", "Paul", "" ] ]
We investigate the production of photons from coherently oscillating, spatially localized clumps of axionic fields (oscillons and axion stars) in the presence of external electromagnetic fields. We delineate different qualitative behaviour of the photon luminosity in terms of an effective dimensionless coupling parameter constructed out of the axion-photon coupling, and field amplitude, oscillation frequency and radius of the axion star. For small values of this dimensionless coupling, we provide a general analytic formula for the dipole radiation field and the photon luminosity per solid angle, including a strong dependence on the radius of the configuration. For moderate to large coupling, we report on a non-monotonic behavior of the luminosity with the coupling strength in the presence of external magnetic fields. After an initial rise in luminosity with the coupling strength, we see a suppression (by an order of magnitude or more compared to the dipole radiation approximation) at moderately large coupling. At sufficiently large coupling, we find a transition to a regime of exponential growth of the luminosity due to parametric resonance. We carry out 3+1 dimensional lattice simulations of axion electrodynamics, at small and large coupling, including non-perturbative effects of parametric resonance as well as backreaction effects when necessary. We also discuss medium (plasma) effects that lead to resonant axion to photon conversion, relevance of the coherence of the soliton, and implications of our results in astrophysical and cosmological settings.
hep-ph/9909471
John R. Hiller
J. R. Hiller (University of Minnesota Duluth)
On the Use of Discrete Light-Cone Quantization to Compute Form Factors
7 pages, 3 figures; RevTeX; to appear in the proceedings of the TJNAF workshop on the Transition from Low to High Q Form Factors, Athens, GA, September 17, 1999
null
null
UMN-D-99-3
hep-ph
null
Techniques for the field-theoretic calculation of a form factor are described and applied to a dressed-fermion state of a (3+1)-dimensional model Hamiltonian. Discrete light-cone quantization plays the crucial role as the means by which Fock-state wave functions are computed. An ultraviolet infinity is controlled by Pauli-Villars regularization.
[ { "created": "Wed, 22 Sep 1999 15:22:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hiller", "J. R.", "", "University of Minnesota Duluth" ] ]
Techniques for the field-theoretic calculation of a form factor are described and applied to a dressed-fermion state of a (3+1)-dimensional model Hamiltonian. Discrete light-cone quantization plays the crucial role as the means by which Fock-state wave functions are computed. An ultraviolet infinity is controlled by Pauli-Villars regularization.
2207.14515
Hanying Xiong
Bowen Wang, Kai Wang, Hanying Xiong
Electroweak corrections to Higgs boson production via W W fusion at the future LHeC
null
null
10.1103/PhysRevD.106.093011
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Precision measurement of quark Yukawa couplings is a crucial aspect of Higgs property study. Proposed as a future upgrade of the Large Hadron Collider (LHC), the Large Hadron electron Collider (LHeC) provides opportunities to probe quark Yukawa couplings with a high precision because of relatively low rate from QCD background as compared with that of the Higgs processes at the LHC. For this purpose, it is important to have a precision prediction of the Higgs production rate at the LHeC. The leading production channel of the Higgs boson at the LHeC is via weak boson fusion (WBF) which has the unique kinematic feature of forward tagging jets. Since there is no color exchange between the forward-backward objects in WBF processes, electroweak radiative corrections become particularly important. In this paper, we focus on the electroweak radiative corrections at next-to-leading order for Higgs boson production in the WBF channel at the LHeC. In the two renormalization schemes we use, the loop corrections are respectively at the level of 9% and 18% relative to the leading order result, and the next-to-leading calculation in both schemes agree up to a truncation error expected from the perturbative method. The size of the EW correction exceeds that from QCD radiations and is shown to be important for the study of Higgs phenomenology.
[ { "created": "Fri, 29 Jul 2022 07:22:50 GMT", "version": "v1" }, { "created": "Mon, 6 Mar 2023 03:46:39 GMT", "version": "v2" } ]
2023-03-07
[ [ "Wang", "Bowen", "" ], [ "Wang", "Kai", "" ], [ "Xiong", "Hanying", "" ] ]
Precision measurement of quark Yukawa couplings is a crucial aspect of Higgs property study. Proposed as a future upgrade of the Large Hadron Collider (LHC), the Large Hadron electron Collider (LHeC) provides opportunities to probe quark Yukawa couplings with a high precision because of relatively low rate from QCD background as compared with that of the Higgs processes at the LHC. For this purpose, it is important to have a precision prediction of the Higgs production rate at the LHeC. The leading production channel of the Higgs boson at the LHeC is via weak boson fusion (WBF) which has the unique kinematic feature of forward tagging jets. Since there is no color exchange between the forward-backward objects in WBF processes, electroweak radiative corrections become particularly important. In this paper, we focus on the electroweak radiative corrections at next-to-leading order for Higgs boson production in the WBF channel at the LHeC. In the two renormalization schemes we use, the loop corrections are respectively at the level of 9% and 18% relative to the leading order result, and the next-to-leading calculation in both schemes agree up to a truncation error expected from the perturbative method. The size of the EW correction exceeds that from QCD radiations and is shown to be important for the study of Higgs phenomenology.
2103.12145
Roberto Vega-Morales
Mar Bastero-Gil, Jose Santiago, Lorenzo Ubaldi, Roberto Vega-Morales
Dark photon dark matter from a rolling inflaton
35 pages + Appendix, 12 Figures
null
10.1088/1475-7516/2022/02/015
UG-FT 333-21, CAFPE 203-21
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study in detail a recently proposed mechanism for producing non-thermal dark photon dark matter at the end of inflation in the mass range $\mu\,{\rm eV} \lesssim m \lesssim 10\,{\rm TeV}$. A tachyonic instability induced by a rolling inflaton leads to the coherent production of dark (abelian) gauge bosons with a peak in the power spectrum corresponding to the Hubble scale at the end of inflation. As the Universe expands after inflation the dark photons redshift and, at some point in their cosmic evolution, they obtain a mass. We focus in particular on the case where the dark photons are relativistic at the time their mass is generated and examine the associated cosmic evolution to compute the relic abundance today. We also examine the late time power spectrum demonstrating explicitly that it preserves the peak generated at the end of inflation. We show that the peak corresponds to small physical scales today, $\ell_{\rm today} \sim {\rm cm} - 100\,{\rm km}$, with large density fluctuations at $\ell_{\rm today}$ leading to a clumpy nature for the dark photon dark matter. We also discuss potential phenomenology and future directions, briefly commenting on the non-relativistic case.
[ { "created": "Mon, 22 Mar 2021 19:40:10 GMT", "version": "v1" } ]
2022-02-16
[ [ "Bastero-Gil", "Mar", "" ], [ "Santiago", "Jose", "" ], [ "Ubaldi", "Lorenzo", "" ], [ "Vega-Morales", "Roberto", "" ] ]
We study in detail a recently proposed mechanism for producing non-thermal dark photon dark matter at the end of inflation in the mass range $\mu\,{\rm eV} \lesssim m \lesssim 10\,{\rm TeV}$. A tachyonic instability induced by a rolling inflaton leads to the coherent production of dark (abelian) gauge bosons with a peak in the power spectrum corresponding to the Hubble scale at the end of inflation. As the Universe expands after inflation the dark photons redshift and, at some point in their cosmic evolution, they obtain a mass. We focus in particular on the case where the dark photons are relativistic at the time their mass is generated and examine the associated cosmic evolution to compute the relic abundance today. We also examine the late time power spectrum demonstrating explicitly that it preserves the peak generated at the end of inflation. We show that the peak corresponds to small physical scales today, $\ell_{\rm today} \sim {\rm cm} - 100\,{\rm km}$, with large density fluctuations at $\ell_{\rm today}$ leading to a clumpy nature for the dark photon dark matter. We also discuss potential phenomenology and future directions, briefly commenting on the non-relativistic case.
hep-ph/0208202
Gerhard Buchalla
Stefan W. Bosch, Gerhard Buchalla
The Double Radiative Decays $B\to\gamma\gamma$ in the Heavy Quark Limit
20 pages, 6 figures
JHEP 0208:054,2002
10.1088/1126-6708/2002/08/054
MPI-PHT-2002-19, LMU 02/04
hep-ph
null
We analyze the double radiative B-meson decays B_s -> gamma gamma and B_d -> gamma gamma in QCD factorization based on the heavy-quark limit m_b >> Lambda_QCD. We systematically discuss the various contributions to these exclusive processes. The dominant effect arises from the magnetic-moment type transition b -> s(d) gamma where an additional photon is emitted from the light quark (one-particle reducible diagram). The contributions from one-particle irreducible diagrams are power suppressed. We argue that they are still calculable within QCD factorization. They are used to compute the CP-asymmetries in B -> gamma gamma and to estimate so-called long-distance contributions in B and D -> gamma gamma. Numerical results are presented for branching ratios and CP asymmetries.
[ { "created": "Thu, 22 Aug 2002 15:11:15 GMT", "version": "v1" } ]
2009-11-07
[ [ "Bosch", "Stefan W.", "" ], [ "Buchalla", "Gerhard", "" ] ]
We analyze the double radiative B-meson decays B_s -> gamma gamma and B_d -> gamma gamma in QCD factorization based on the heavy-quark limit m_b >> Lambda_QCD. We systematically discuss the various contributions to these exclusive processes. The dominant effect arises from the magnetic-moment type transition b -> s(d) gamma where an additional photon is emitted from the light quark (one-particle reducible diagram). The contributions from one-particle irreducible diagrams are power suppressed. We argue that they are still calculable within QCD factorization. They are used to compute the CP-asymmetries in B -> gamma gamma and to estimate so-called long-distance contributions in B and D -> gamma gamma. Numerical results are presented for branching ratios and CP asymmetries.
1801.05023
Elena Villhauer
Elena Villhauer
Noncommutative Black Holes at the LHC
null
IOP Conf. Series: Journal of Physics: Conf. Series 942 (2017) 012019
10.1088/1742-6596/942/1/012019
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on the latest public results, 13 TeV data from the Large Hadron Collider at CERN has not indicated any evidence of hitherto tested models of quantum black holes, semiclassical black holes, or string balls. Such models have predicted signatures of particles with high transverse momenta. Noncommutative black holes remain an untested model of TeV- scale gravity that offers the starkly different signature of particles with relatively low transverse momenta. Considerations for a search for charged noncommutative black holes using the ATLAS detector will be discussed.
[ { "created": "Fri, 12 Jan 2018 04:10:51 GMT", "version": "v1" } ]
2018-01-17
[ [ "Villhauer", "Elena", "" ] ]
Based on the latest public results, 13 TeV data from the Large Hadron Collider at CERN has not indicated any evidence of hitherto tested models of quantum black holes, semiclassical black holes, or string balls. Such models have predicted signatures of particles with high transverse momenta. Noncommutative black holes remain an untested model of TeV- scale gravity that offers the starkly different signature of particles with relatively low transverse momenta. Considerations for a search for charged noncommutative black holes using the ATLAS detector will be discussed.
hep-ph/9709324
null
Zhenjun Xiao
Technicolor leptoquarks and the excess of NC and CC events with high-$Q^2$ at HERA
26 pages, Latex, no macros, two PS figures and 1 embedded latex figure
null
null
RAL-TR-97-043
hep-ph
null
In this paper we pursue a consistent leptoquark interpretation for HERA anomalies in the framework of Technicolor. We find that: (a) one F=0 scalar Technicolor leptoquark $P_3^{'}$ with a mass of 200 GeV can provide the required contributions to account for the excess of both neutral and charged current events with high-$Q^2$ at HERA; (b) the current data still allow the coexistence of $ P_3^{'}$ with m(P_3^{'})= 200 GeV$ and $P_3^0$ with $m(P_3^0)=225 GeV$, they could contribute effectively to $e^+p$ collision process and may be responsible for the apparent splitting of average mass of H1 and ZEUS NC events with high-$Q^2$.
[ { "created": "Fri, 12 Sep 1997 08:20:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Xiao", "Zhenjun", "" ] ]
In this paper we pursue a consistent leptoquark interpretation for HERA anomalies in the framework of Technicolor. We find that: (a) one F=0 scalar Technicolor leptoquark $P_3^{'}$ with a mass of 200 GeV can provide the required contributions to account for the excess of both neutral and charged current events with high-$Q^2$ at HERA; (b) the current data still allow the coexistence of $ P_3^{'}$ with m(P_3^{'})= 200 GeV$ and $P_3^0$ with $m(P_3^0)=225 GeV$, they could contribute effectively to $e^+p$ collision process and may be responsible for the apparent splitting of average mass of H1 and ZEUS NC events with high-$Q^2$.
hep-ph/0109171
Schildknecht
D. Schildknecht
Scaling and asymptotic behavior of the $\gamma^* p$ total cross section at low x
8 pages, Latex using psfig, 5 figures, documentclass elsart. Presented at IX Blois Workshop on Elastic and Diffractive Scattering, Pruhonice near Prague, Czech Republic, June 9-15, 2001
null
null
null
hep-ph
null
The scaling in $\sigma_{\gamma^*p}$ cross sections (for $Q^2/W^2 << 1$) in terms of the scaling variable $\eta = (Q^2 + m^2_0)/\Lambda^2 (W^2)$ is interpreted in the generalized vector dominance/color-dipole picture (GVD/CDP). The quantity $\Lambda^2 (W^2)$ is identified as the average gluon transverse momentum absorbed by the $q \bar q$ state, $<\vec l^{~2}> = (1/6) \Lambda^2 (W^2)$. At any $Q^2$, for $W^2 \to \infty$, the cross sections for virtual and real photons become universal, $\sigma_{\gamma^*p}(W^2,Q^2)/\sigma_{\gamma p}(W^2) \to 1$. The gluon density corresponding to the color-dipole cross section in the appropriate limit is found to be consistent with the results from QCD fits.
[ { "created": "Wed, 19 Sep 2001 15:24:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Schildknecht", "D.", "" ] ]
The scaling in $\sigma_{\gamma^*p}$ cross sections (for $Q^2/W^2 << 1$) in terms of the scaling variable $\eta = (Q^2 + m^2_0)/\Lambda^2 (W^2)$ is interpreted in the generalized vector dominance/color-dipole picture (GVD/CDP). The quantity $\Lambda^2 (W^2)$ is identified as the average gluon transverse momentum absorbed by the $q \bar q$ state, $<\vec l^{~2}> = (1/6) \Lambda^2 (W^2)$. At any $Q^2$, for $W^2 \to \infty$, the cross sections for virtual and real photons become universal, $\sigma_{\gamma^*p}(W^2,Q^2)/\sigma_{\gamma p}(W^2) \to 1$. The gluon density corresponding to the color-dipole cross section in the appropriate limit is found to be consistent with the results from QCD fits.
hep-ph/0207317
Dmitri Ivanov
D.Yu. Ivanov
QCD Factorization for the Pion Diffractive Dissociation Into Two Jets
6 pages, latex, two figures
null
10.1142/9789812776211_0025
null
hep-ph
null
We report a detailed study of the process of pion diffraction dissociation into two jets with large transverse momenta. We find that the standard collinear factorization does not hold in this reaction. The structure of non-factorizable contributions is discussed and the results are compared with the experimental data. Our conclusion is that the existing theoretical uncertainties do not allow, for the time being, for a quantitative extraction of the pion distribution amplitude. (Talk presented at the Workshop on Exclusive Processes at High Momentum Transfer, Jefferson News, VA, May 15-18, 2002)
[ { "created": "Fri, 26 Jul 2002 09:02:49 GMT", "version": "v1" } ]
2017-08-23
[ [ "Ivanov", "D. Yu.", "" ] ]
We report a detailed study of the process of pion diffraction dissociation into two jets with large transverse momenta. We find that the standard collinear factorization does not hold in this reaction. The structure of non-factorizable contributions is discussed and the results are compared with the experimental data. Our conclusion is that the existing theoretical uncertainties do not allow, for the time being, for a quantitative extraction of the pion distribution amplitude. (Talk presented at the Workshop on Exclusive Processes at High Momentum Transfer, Jefferson News, VA, May 15-18, 2002)
hep-ph/0201271
Sherstnev Alexandre
E.E. Boos, A.V. Sherstnev
Spin Effects in Processes of Single Top Quark Production at Hadron Colliders
14 pages, latex
Phys.Lett. B534 (2002) 97-105
10.1016/S0370-2693(02)01659-3
null
hep-ph
null
We investigate spin properties of single top quark production at hadron colliders. Based on an analogy with single top production and polarized top quark decay, we reproduce in a simple way the results by G.Mahlon and S.Parke on the existence of preferred axes for the decomposition of the top quark spin. For the W*- and W-g fusion production modes these axes are related to the down-type quark momentum. The proposed method allows finding kinematical conditions for the observation of top quark polarization in a third process that contributes to single top production and is important at LHC energies, the tW-process, in which spin effects are smeared out by the contribution of diagrams with a QCD gtt-vertex. A simple Monte-Carlo analysis of spin correlations for the tW-process with subsequent top decay is given as an illustration.
[ { "created": "Tue, 29 Jan 2002 16:37:48 GMT", "version": "v1" } ]
2009-11-07
[ [ "Boos", "E. E.", "" ], [ "Sherstnev", "A. V.", "" ] ]
We investigate spin properties of single top quark production at hadron colliders. Based on an analogy with single top production and polarized top quark decay, we reproduce in a simple way the results by G.Mahlon and S.Parke on the existence of preferred axes for the decomposition of the top quark spin. For the W*- and W-g fusion production modes these axes are related to the down-type quark momentum. The proposed method allows finding kinematical conditions for the observation of top quark polarization in a third process that contributes to single top production and is important at LHC energies, the tW-process, in which spin effects are smeared out by the contribution of diagrams with a QCD gtt-vertex. A simple Monte-Carlo analysis of spin correlations for the tW-process with subsequent top decay is given as an illustration.
2210.04841
Chengrong Deng
Jia Wei, Yi-Heng Wang, Chun-Sheng An, and Cheng-Rong Deng
Color flux-tube nature of the states $T_{cs}(2900)$ and $T^a_{c\bar{s}}(2900)$
9 pages, 4 tables, comments are welcome
Phys. RevD.106.096023 (2022)
10.1103/PhysRevD.106.096023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the states $T_{cs0}(2900)^0$, $T_{cs1}(2900)^0$, $T^a_{c\bar{s}0}(2900)^{0}$ and $T^a_{c\bar{s}0}(2900)^{++}$ reported by the LHCb Collaboration, we carry out a systematical investigation on the properties of the ground and $P$-wave states $[cs][\bar{u}\bar{d}]$ and $[cu][\bar{s}\bar{d}]$ with various spin, isospin or $U$-spin, and color combinations in a multiquark color flux-tube model. Matching our results with the spin-parity and mass of the states $T_{cs0}(2900)^0$ and $T_{cs1}(2900)^0$, we can describe them as the compact states $[cs][\bar{u}\bar{d}]$ with $I(J^{P})=1(0^+)$ and $0(1^-)$ in the model, respectively. The ground state $T_{cs0}(2900)^0$ is mainly made of strongly overlapped an axial-vector $[cs]_{\bar{\mathbf{3}}_c}$ and an axial-vector $[\bar{u}\bar{d}]_{\mathbf{3}_c}$. The $P$-wave state $T_{cs1}(2900)^0$ is dominantly consisted of a gradually separated scalar or axial vector $[cs]_{\bar{\mathbf{3}}_c}$ and a scalar $[\bar{u}\bar{d}]_{\mathbf{3}_c}$ in the shape of a dumbbell. Supposing the states $T^a_{c\bar{s}0}(2900)^{0}$ and $T^a_{c\bar{s}0}(2900)^{++}$ belong to the same isospin triplet, the mass of the state $\left [[cu]_{\bar{\mathbf{3}}_c}[\bar{s}\bar{d}]_ {\mathbf{3}_c}\right ]_{\mathbf{1}_c}$ with symmetrical $U$-spin and $J^P=0^+$ is highly consistent with that of the states $T^a_{c\bar{s}0}(2900)^{0}$ and $T^a_{c\bar{s}0}(2900)^{++}$ in the model. After coupling two color configurations, the state $[cu][\bar{s}\bar{d}]$ is slightly lighter than the states $T^a_{c\bar{s}0}(2900)^{0}$ and $T^a_{c\bar{s}0}(2900)^{++}$. In addition, we also discuss the properties of other states in the model.
[ { "created": "Mon, 10 Oct 2022 16:55:38 GMT", "version": "v1" }, { "created": "Mon, 28 Nov 2022 16:50:47 GMT", "version": "v2" } ]
2022-11-29
[ [ "Wei", "Jia", "" ], [ "Wang", "Yi-Heng", "" ], [ "An", "Chun-Sheng", "" ], [ "Deng", "Cheng-Rong", "" ] ]
Inspired by the states $T_{cs0}(2900)^0$, $T_{cs1}(2900)^0$, $T^a_{c\bar{s}0}(2900)^{0}$ and $T^a_{c\bar{s}0}(2900)^{++}$ reported by the LHCb Collaboration, we carry out a systematical investigation on the properties of the ground and $P$-wave states $[cs][\bar{u}\bar{d}]$ and $[cu][\bar{s}\bar{d}]$ with various spin, isospin or $U$-spin, and color combinations in a multiquark color flux-tube model. Matching our results with the spin-parity and mass of the states $T_{cs0}(2900)^0$ and $T_{cs1}(2900)^0$, we can describe them as the compact states $[cs][\bar{u}\bar{d}]$ with $I(J^{P})=1(0^+)$ and $0(1^-)$ in the model, respectively. The ground state $T_{cs0}(2900)^0$ is mainly made of strongly overlapped an axial-vector $[cs]_{\bar{\mathbf{3}}_c}$ and an axial-vector $[\bar{u}\bar{d}]_{\mathbf{3}_c}$. The $P$-wave state $T_{cs1}(2900)^0$ is dominantly consisted of a gradually separated scalar or axial vector $[cs]_{\bar{\mathbf{3}}_c}$ and a scalar $[\bar{u}\bar{d}]_{\mathbf{3}_c}$ in the shape of a dumbbell. Supposing the states $T^a_{c\bar{s}0}(2900)^{0}$ and $T^a_{c\bar{s}0}(2900)^{++}$ belong to the same isospin triplet, the mass of the state $\left [[cu]_{\bar{\mathbf{3}}_c}[\bar{s}\bar{d}]_ {\mathbf{3}_c}\right ]_{\mathbf{1}_c}$ with symmetrical $U$-spin and $J^P=0^+$ is highly consistent with that of the states $T^a_{c\bar{s}0}(2900)^{0}$ and $T^a_{c\bar{s}0}(2900)^{++}$ in the model. After coupling two color configurations, the state $[cu][\bar{s}\bar{d}]$ is slightly lighter than the states $T^a_{c\bar{s}0}(2900)^{0}$ and $T^a_{c\bar{s}0}(2900)^{++}$. In addition, we also discuss the properties of other states in the model.
hep-ph/9606296
Andrei Afanas'ev
Andrei Afanasev (CEBAF and Hampton U.), W.W. Buck (Universit\"at Mainz, Hampton U. and CEBAF)
Unified Description of Kaon Electroweak Form Factors
RevTeX, 7 pages, 4 postscript figures
Phys.Rev.D55:4380-4384,1997
10.1103/PhysRevD.55.4380
CEBAF-TH-96-12
hep-ph
null
A calculation of the semi--leptonic decays of the kaon ($K_{l3}$) is presented. The results are direct predictions of a covariant model of the pion and kaon introduced earlier by Ito, Buck, Gross. The weak form factors for $K_{l3}$ are predicted with absolutely no parameter adjustments of the model. We obtained for the form factor parameters: $f_-(q^2=m_l^2)/f_+(q^2=m_l^2)=-0.28$ and $\lambda_+$= 0.028, both within experimental error bars. Connections of this approach to heavy quark symmetry will also be discussed.
[ { "created": "Mon, 10 Jun 1996 21:16:14 GMT", "version": "v1" } ]
2014-11-17
[ [ "Afanasev", "Andrei", "", "CEBAF and Hampton U." ], [ "Buck", "W. W.", "", "Universität\n Mainz, Hampton U. and CEBAF" ] ]
A calculation of the semi--leptonic decays of the kaon ($K_{l3}$) is presented. The results are direct predictions of a covariant model of the pion and kaon introduced earlier by Ito, Buck, Gross. The weak form factors for $K_{l3}$ are predicted with absolutely no parameter adjustments of the model. We obtained for the form factor parameters: $f_-(q^2=m_l^2)/f_+(q^2=m_l^2)=-0.28$ and $\lambda_+$= 0.028, both within experimental error bars. Connections of this approach to heavy quark symmetry will also be discussed.
hep-ph/0609140
V\'eronique Pag\'e
Steven Abel and Veronique Page
(Pseudo)-Dirac neutrinos and leptogenesis
7 pages, 1 figure, Talk given at the Dark Side of the Universe Conference 2006 (DSU2006), Madrid, Spain, 20-24 June 2006
null
10.1063/1.2409106
null
hep-ph
null
We discuss how Dirac neutrinos can naturally be generated in supersymmetry and how they allow for an Affleck-Dine leptogenesis scenario, in which a left-right asymmetry is generated in the sneutrino sector, the left part of which is transferred to a baryon asymmetry via sphaleron transitions. No exotic fields need to be added to the MSSM other than the right-handed neutrino.
[ { "created": "Thu, 14 Sep 2006 15:52:50 GMT", "version": "v1" } ]
2009-11-11
[ [ "Abel", "Steven", "" ], [ "Page", "Veronique", "" ] ]
We discuss how Dirac neutrinos can naturally be generated in supersymmetry and how they allow for an Affleck-Dine leptogenesis scenario, in which a left-right asymmetry is generated in the sneutrino sector, the left part of which is transferred to a baryon asymmetry via sphaleron transitions. No exotic fields need to be added to the MSSM other than the right-handed neutrino.
0710.1997
Kingman Cheung
Kingman Cheung, Jeonghyeon Song, Qi-Shu Yan
Roles of Higgs decay into two pseudoscalar bosons in the search of intermediate-mass Higgs Boson
Submitted for the SUSY07 proceedings. 4 pages, 1 figure
null
null
null
hep-ph
null
The dominance of $h\to \eta \eta$ decay mode for the intermediate mass Higgs boson is highly motivated to solve the little hierarchy problem and to ease the tension with the precision data. However, the discovery modes for $m_h \alt 150$ GeV, $h \to \gamma\gamma$ and $W/Z h \to (\ell\nu/\ell \bar \ell) (b\bar b)$, will be substantially affected. We show that $h \to \eta \eta \to 4b$ is complementary and we can use this decay mode to detect the intermediate Higgs boson at the LHC, via $Wh$ and $Zh$ production. Requiring at least one charged lepton and 4 $B$-tags in the final state, we can identify a clean Higgs boson signal for $m_h \alt 150$ GeV with a high significance and with a full Higgs mass reconstruction. We use the next-to-minimal supersymmetric standard model and the simplest little Higgs model for illustration.
[ { "created": "Wed, 10 Oct 2007 12:45:24 GMT", "version": "v1" } ]
2007-10-11
[ [ "Cheung", "Kingman", "" ], [ "Song", "Jeonghyeon", "" ], [ "Yan", "Qi-Shu", "" ] ]
The dominance of $h\to \eta \eta$ decay mode for the intermediate mass Higgs boson is highly motivated to solve the little hierarchy problem and to ease the tension with the precision data. However, the discovery modes for $m_h \alt 150$ GeV, $h \to \gamma\gamma$ and $W/Z h \to (\ell\nu/\ell \bar \ell) (b\bar b)$, will be substantially affected. We show that $h \to \eta \eta \to 4b$ is complementary and we can use this decay mode to detect the intermediate Higgs boson at the LHC, via $Wh$ and $Zh$ production. Requiring at least one charged lepton and 4 $B$-tags in the final state, we can identify a clean Higgs boson signal for $m_h \alt 150$ GeV with a high significance and with a full Higgs mass reconstruction. We use the next-to-minimal supersymmetric standard model and the simplest little Higgs model for illustration.
hep-ph/0212393
Alexander Studenikin
A.Lobanov, A.Studenikin
Spin light of neutrino in matter and electromagnetic fields
accepted for publication in Phys.Lett.B
Phys.Lett. B564 (2003) 27-34
10.1016/S0370-2693(03)00570-7
null
hep-ph
null
A new type of electromagnetic radiation by a neutrino with non-zero magnetic (and/or electric) moment moving in background matter and electromagnetic field is considered. This radiation originates from the quantum spin flip transitions and we have named it as "spin light of neutrino"($SL\nu$). The neutrino initially unpolarized beam (equal mixture of $\nu_{L}$ and $\nu_{R}$) can be converted to the totally polarized beam composed of only $\nu_{R}$ by the neutrino spin light in matter and electromagnetic fields. The quasi-classical theory of this radiation is developed on the basis of the generalized Bargmann-Michel-Telegdi equation. The considered radiation is important for environments with high effective densities, $n$, because the total radiation power is proportional to $n^{4}$. The spin light of neutrino, in contrast to the Cherenkov or transition radiation of neutrino in matter, does not vanish in the case of the refractive index of matter is equal to unit. The specific features of this new radiation are: (i) the total power of the radiation is proportional to $\gamma ^{4}$, and (ii) the radiation is beamed within a small angle $\delta \theta \sim \gamma^{-1}$, where $\gamma$ is the neutrino Lorentz factor. Applications of this new type of neutrino radiation to astrophysics, in particular to gamma-ray bursts, and the early universe should be important.
[ { "created": "Mon, 30 Dec 2002 14:15:02 GMT", "version": "v1" }, { "created": "Mon, 6 Jan 2003 12:46:38 GMT", "version": "v2" }, { "created": "Thu, 10 Apr 2003 17:30:03 GMT", "version": "v3" } ]
2009-11-07
[ [ "Lobanov", "A.", "" ], [ "Studenikin", "A.", "" ] ]
A new type of electromagnetic radiation by a neutrino with non-zero magnetic (and/or electric) moment moving in background matter and electromagnetic field is considered. This radiation originates from the quantum spin flip transitions and we have named it as "spin light of neutrino"($SL\nu$). The neutrino initially unpolarized beam (equal mixture of $\nu_{L}$ and $\nu_{R}$) can be converted to the totally polarized beam composed of only $\nu_{R}$ by the neutrino spin light in matter and electromagnetic fields. The quasi-classical theory of this radiation is developed on the basis of the generalized Bargmann-Michel-Telegdi equation. The considered radiation is important for environments with high effective densities, $n$, because the total radiation power is proportional to $n^{4}$. The spin light of neutrino, in contrast to the Cherenkov or transition radiation of neutrino in matter, does not vanish in the case of the refractive index of matter is equal to unit. The specific features of this new radiation are: (i) the total power of the radiation is proportional to $\gamma ^{4}$, and (ii) the radiation is beamed within a small angle $\delta \theta \sim \gamma^{-1}$, where $\gamma$ is the neutrino Lorentz factor. Applications of this new type of neutrino radiation to astrophysics, in particular to gamma-ray bursts, and the early universe should be important.
hep-ph/9601303
Stuart Raby
Vincent Lucas and Stuart Raby (The Ohio State University)
GUT Scale Threshold Corrections in a Complete Supersymmetric SO(10) Model: $\alpha_s(M_Z)$ vs. Proton Lifetime
29 pages, using revtex, 2 figures (not included)
Phys.Rev.D54:2261-2272,1996
10.1103/PhysRevD.54.2261
OHSTPY-HEP-T-95-028
hep-ph
null
We show that one loop GUT scale threshold corrections to gauge couplings are a significant constraint on the GUT symmetry breaking sector of the theory. The one loop threshold corrections relate the prediction for $\alpha_s(M_Z)$ to the proton lifetime. We have calculated these corrections in a new complete SO(10) SUSY GUT. The results are consistent with the low energy measurement of $\alpha_s(M_Z)$. We have also calculated the proton lifetime and branching ratios in this model. We show that proton decay rates provide a powerful test for theories of fermion masses.
[ { "created": "Fri, 19 Jan 1996 23:13:16 GMT", "version": "v1" } ]
2014-11-17
[ [ "Lucas", "Vincent", "", "The Ohio State University" ], [ "Raby", "Stuart", "", "The Ohio State University" ] ]
We show that one loop GUT scale threshold corrections to gauge couplings are a significant constraint on the GUT symmetry breaking sector of the theory. The one loop threshold corrections relate the prediction for $\alpha_s(M_Z)$ to the proton lifetime. We have calculated these corrections in a new complete SO(10) SUSY GUT. The results are consistent with the low energy measurement of $\alpha_s(M_Z)$. We have also calculated the proton lifetime and branching ratios in this model. We show that proton decay rates provide a powerful test for theories of fermion masses.
1504.06230
Takahiro Terada
Takahiro Terada
Toward Higgs inflation in the MSSM
4 pages, 1 figure; a contribution to the proceedings of The 2nd Toyama International Workshop on "Higgs as a Probe of New Physics 2015" (HPNP2015), based on a poster presentation given there
null
null
UT-15-13; DESY 15-055
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Adopting a recently proposed single-superfield framework of supergravity inflation, we consider large field inflationary models in which MSSM Higgs-like fields play the role of the inflaton. In the simplest cases, the inflaton potential has a fractional power, which is different from that of the original Higgs inflation, and it can be tested by cosmological observations in near future. We find difficulties in identifying the inflaton with the MSSM Higgses and discuss possible candidates of the inflaton.
[ { "created": "Thu, 23 Apr 2015 15:49:07 GMT", "version": "v1" } ]
2015-04-24
[ [ "Terada", "Takahiro", "" ] ]
Adopting a recently proposed single-superfield framework of supergravity inflation, we consider large field inflationary models in which MSSM Higgs-like fields play the role of the inflaton. In the simplest cases, the inflaton potential has a fractional power, which is different from that of the original Higgs inflation, and it can be tested by cosmological observations in near future. We find difficulties in identifying the inflaton with the MSSM Higgses and discuss possible candidates of the inflaton.
hep-ph/0112274
Carsten Vogt
M. Diehl, P. Kroll and C. Vogt
The handbag contribution to gamma gamma to pi pi and K K
17 pages, latex, 4 Figures. v2: extended discussion of soft and hard contributions, results unchanged. To appear in Phys. Lett. B
Phys.Lett. B532 (2002) 99-110
10.1016/S0370-2693(02)01489-2
WU B 01-14, PITHA 01/13, NORDITA-2001-84 HE
hep-ph
null
We investigate the soft handbag contribution to two-photon annihilation into pion or kaon pairs at large energy and momentum transfer. The amplitude is expressed as a hard gamma gamma -> q qbar subprocess times a form factor describing the soft transition from q qbar to the meson pair. We find the calculated angular dependence of the cross section in good agreement with data, and extract annihilation form factors of plausible size. A key prediction of the handbag mechanism is that the differential cross section is the same for charged and neutral pion pairs, in striking contrast with what is found in the hard scattering approach.
[ { "created": "Thu, 20 Dec 2001 13:22:36 GMT", "version": "v1" }, { "created": "Fri, 22 Feb 2002 12:49:15 GMT", "version": "v2" } ]
2009-11-07
[ [ "Diehl", "M.", "" ], [ "Kroll", "P.", "" ], [ "Vogt", "C.", "" ] ]
We investigate the soft handbag contribution to two-photon annihilation into pion or kaon pairs at large energy and momentum transfer. The amplitude is expressed as a hard gamma gamma -> q qbar subprocess times a form factor describing the soft transition from q qbar to the meson pair. We find the calculated angular dependence of the cross section in good agreement with data, and extract annihilation form factors of plausible size. A key prediction of the handbag mechanism is that the differential cross section is the same for charged and neutral pion pairs, in striking contrast with what is found in the hard scattering approach.
hep-ph/0411396
Frank Close Prof
F.E.Close
Hadron Spectroscopy (theory): Diquarks, Tetraquarks, Pentaquarks and no quarks
Plenary talk at ICHEP04
Int.J.Mod.Phys. A20 (2005) 5156-5163
10.1142/S0217751X05028661
OUTP-04-24
hep-ph
null
States beyond those expected in the simple constituent quark model are now emerging. I focus on the scalar glueball and its mixing with states in the $q\bar{q}$ nonet, and also on correlations in Strong QCD that may form diquarks and seed $qq\bar{q}\bar{q}$ states. Some models of the pentaquark candidate $\Theta(1540)$ are critically discussed.
[ { "created": "Tue, 30 Nov 2004 11:42:40 GMT", "version": "v1" } ]
2009-11-10
[ [ "Close", "F. E.", "" ] ]
States beyond those expected in the simple constituent quark model are now emerging. I focus on the scalar glueball and its mixing with states in the $q\bar{q}$ nonet, and also on correlations in Strong QCD that may form diquarks and seed $qq\bar{q}\bar{q}$ states. Some models of the pentaquark candidate $\Theta(1540)$ are critically discussed.
hep-ph/0205158
Fedor Bezrukov
F. Bezrukov, D. Gorbunov
T-Odd Correlations in pi->e nu_e gamma and pi->mu nu_mu gamma Decays
19 pages, 5 figures. To be published in Phys.Rev.D. Fixed sign in FSI contribution figure, fixed formulas in K-bar{K} mixing analysis, added some minor comments
Phys.Rev. D66 (2002) 054012
10.1103/PhysRevD.66.054012
null
hep-ph hep-ex
null
The transverse lepton polarization asymmetry in pi_l2gamma decays may probe T-violating interactions beyond the Standard Model. Dalitz plot distributions of the expected effects are presented and compared to the contribution from the Standard Model final state interactions. We give an example of a phenomenologically viable model, where a considerable contribution to the transverse lepton polarization asymmetry arises.
[ { "created": "Wed, 15 May 2002 13:52:44 GMT", "version": "v1" }, { "created": "Tue, 6 Aug 2002 19:05:21 GMT", "version": "v2" } ]
2009-11-07
[ [ "Bezrukov", "F.", "" ], [ "Gorbunov", "D.", "" ] ]
The transverse lepton polarization asymmetry in pi_l2gamma decays may probe T-violating interactions beyond the Standard Model. Dalitz plot distributions of the expected effects are presented and compared to the contribution from the Standard Model final state interactions. We give an example of a phenomenologically viable model, where a considerable contribution to the transverse lepton polarization asymmetry arises.
2403.13456
Wen-Xuan Zhang
Chang-Le Liu, Wen-Xuan Zhang and Duojie Jia
Masses and decays of triply-heavy pentaquarks
12 pages, 10 tables, 3 figures and two appendices, to be published in Chinese Physics C
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this work, we study masses and decays of triply-heavy pentaquarks $QQQn\bar{n}(Q=b,c)$ in the unified MIT bag model. We construct the color-spin wave functions of the triply-heavy pentaquarks we address and use numerical variational method to compute all ground-state masses of these system. By excluding the scattering states in these configurations, we compute the decay width ratios of each decay channels relative to the maximum width for the compact pentaquark states, obtaining main decay modes of the triply-heavy pentaquark systems.
[ { "created": "Wed, 20 Mar 2024 10:04:07 GMT", "version": "v1" }, { "created": "Wed, 5 Jun 2024 08:03:11 GMT", "version": "v2" } ]
2024-06-06
[ [ "Liu", "Chang-Le", "" ], [ "Zhang", "Wen-Xuan", "" ], [ "Jia", "Duojie", "" ] ]
In this work, we study masses and decays of triply-heavy pentaquarks $QQQn\bar{n}(Q=b,c)$ in the unified MIT bag model. We construct the color-spin wave functions of the triply-heavy pentaquarks we address and use numerical variational method to compute all ground-state masses of these system. By excluding the scattering states in these configurations, we compute the decay width ratios of each decay channels relative to the maximum width for the compact pentaquark states, obtaining main decay modes of the triply-heavy pentaquark systems.
2008.00578
Andre Hoang
Andr\'e H. Hoang and Christoph Regner
Borel Representation of $\tau$ Hadronic Spectral Function Moments in Contour-Improved Perturbation Theory
53 pages, 10 figures, revision of presentation and implications with respect to earlier versions, analytic results unchanged, version published in Phys. Rev. D
null
null
UWThPh-2020-19
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We show that the Borel representations of tau hadronic spectral function moments based on contour-improved perturbation theory (CIPT) in general differ from those obtained within fixed-order perturbation theory (FOPT) in the presence of IR renormalons in the underlying Adler function. The Borel sums obtained from both types of Borel representations in general differ as well, and the apparently conflicting behavior of the FOPT and CIPT spectral function moment series at intermediate orders, which has been subject to many studies in the past literature, can be understood quantitatively using concrete Borel function models. The difference between the CIPT and FOPT Borel sums, which we call the "asymptotic separation", can be computed analytically for any Borel function model and is proportional to inverse exponential terms in the strong coupling. Even though moments can be designed where the asymptotic separation is strongly suppressed, it is as a matter of principle unavoidable. If the Borel function of the Euclidean Adler function has a sizeable gluon condensate renormalon cut, the asymptotic separation can explain the observed disparity of the CIPT and FOPT spectral function moments at the 5-loop level. The existence of the asymptotic separation implies that the power corrections in the operator product expansion for the spectral function moments in the CIPT expansion approach do not have the commonly assumed analytic standard form.
[ { "created": "Sun, 2 Aug 2020 22:40:58 GMT", "version": "v1" }, { "created": "Thu, 13 Aug 2020 13:28:52 GMT", "version": "v2" }, { "created": "Mon, 26 Apr 2021 14:13:30 GMT", "version": "v3" }, { "created": "Wed, 18 May 2022 15:39:20 GMT", "version": "v4" } ]
2022-05-19
[ [ "Hoang", "André H.", "" ], [ "Regner", "Christoph", "" ] ]
We show that the Borel representations of tau hadronic spectral function moments based on contour-improved perturbation theory (CIPT) in general differ from those obtained within fixed-order perturbation theory (FOPT) in the presence of IR renormalons in the underlying Adler function. The Borel sums obtained from both types of Borel representations in general differ as well, and the apparently conflicting behavior of the FOPT and CIPT spectral function moment series at intermediate orders, which has been subject to many studies in the past literature, can be understood quantitatively using concrete Borel function models. The difference between the CIPT and FOPT Borel sums, which we call the "asymptotic separation", can be computed analytically for any Borel function model and is proportional to inverse exponential terms in the strong coupling. Even though moments can be designed where the asymptotic separation is strongly suppressed, it is as a matter of principle unavoidable. If the Borel function of the Euclidean Adler function has a sizeable gluon condensate renormalon cut, the asymptotic separation can explain the observed disparity of the CIPT and FOPT spectral function moments at the 5-loop level. The existence of the asymptotic separation implies that the power corrections in the operator product expansion for the spectral function moments in the CIPT expansion approach do not have the commonly assumed analytic standard form.
hep-ph/0103291
Adrian Dumitru
Adrian Dumitru and Miklos Gyulassy (Columbia Univ.)
The Transverse Energy as a Barometer of a Saturated Plasma
4 Pages, LaTex, 2 Figures; Contribution to the 15th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM 2001), Long Island, New York, January 15 - 20, 2001
Nucl.Phys.A698:471-474,2002
10.1016/S0375-9474(01)01406-3
CU-TP-1015
hep-ph nucl-th
null
The evolution of the gluon plasma produced with saturation initial conditions is calculated via Boltzmann transport theory for nuclear collisions at high energy. The saturation scale increases with the nuclear size and the beam energy, and thus we find that the perturbative rescattering rate decreases relative to the initial longitudinal expansion rate of the plasma. The effective longitudinal pressure remains significantly below the lattice QCD pressure until the plasma cools to near the confinement scale. Therefore, the transverse energy per unit of rapidity and its dependence on beam energy provides a sensitive test of gluon saturation models: the fractional transverse energy loss due to final state interactions is smaller and exhibits a weaker energy dependence than if ideal (nondissipative) hydrodynamics applied throughout the evolution.
[ { "created": "Tue, 27 Mar 2001 19:21:15 GMT", "version": "v1" } ]
2009-10-09
[ [ "Dumitru", "Adrian", "", "Columbia Univ." ], [ "Gyulassy", "Miklos", "", "Columbia Univ." ] ]
The evolution of the gluon plasma produced with saturation initial conditions is calculated via Boltzmann transport theory for nuclear collisions at high energy. The saturation scale increases with the nuclear size and the beam energy, and thus we find that the perturbative rescattering rate decreases relative to the initial longitudinal expansion rate of the plasma. The effective longitudinal pressure remains significantly below the lattice QCD pressure until the plasma cools to near the confinement scale. Therefore, the transverse energy per unit of rapidity and its dependence on beam energy provides a sensitive test of gluon saturation models: the fractional transverse energy loss due to final state interactions is smaller and exhibits a weaker energy dependence than if ideal (nondissipative) hydrodynamics applied throughout the evolution.
hep-ph/0409048
V. A. Yerokhin
V. A. Yerokhin, P. Indelicato, and V. M. Shabaev
Two-loop self-energy correction to the ground-state Lamb shift in H-like ions
a contribution to the conference "Highly Charged Ions 2004"
Nucl.Instrum.Meth. B235 (2005) 36-39
10.1016/j.nimb.2005.03.141
null
hep-ph
null
The two-loop self-energy correction is evaluated to all orders in Z alpha for the ground-state Lamb shift of H-like ions with Z >= 20, where Z is the nuclear charge number and alpha is the fine structure constant. The results obtained are compared with analytical calculations performed within the Z alpha expansion.
[ { "created": "Sun, 5 Sep 2004 09:20:02 GMT", "version": "v1" } ]
2009-11-10
[ [ "Yerokhin", "V. A.", "" ], [ "Indelicato", "P.", "" ], [ "Shabaev", "V. M.", "" ] ]
The two-loop self-energy correction is evaluated to all orders in Z alpha for the ground-state Lamb shift of H-like ions with Z >= 20, where Z is the nuclear charge number and alpha is the fine structure constant. The results obtained are compared with analytical calculations performed within the Z alpha expansion.
0712.0253
Chitta Ranjan Das
C.R. Das and L.V. Laperashvili
Dark Energy and Dark Matter, Mirror World and E_6 Unification
38 pages 4 figs; A talk presented at the Conference of Russian Academy of Sciences: Fundamental Interactions Physics, ITEP, Moscow, Russia, Nov 26-30, 2007
null
null
CHEP-PKU/1/12-2007
hep-ph astro-ph
null
In the present talk we have developed a concept of parallel ordinary (O) and mirror (M) worlds. We have shown that in the case of a broken mirror parity (MP), the evolutions of fine structure constants in the O- and M-worlds are not identical. It is assumed that E_6-unification inspired by superstring theory restores the broken MP at the scale \sim 10^{18} GeV, what unavoidably leads to the different E_6-breakdowns at this scale: E_6 \to SO(10)\times U(1)_Z - in the O-world, and E'_6 \to SU(6)'\times SU(2)'_Z - in the M-world. Considering only asymptotically free theories, we have presented the running of all the inverse gauge constants \alpha_i^{-1} in the one-loop approximation. Then a `quintessence' scenario is discussed for the model of accelerating universe. Such a scenario is related with an axion (`acceleron') of a new gauge group SU(2)'_Z which has a coupling constant g_Z extremely growing at the scale \Lambda_Z\sim 10^{-3} eV.
[ { "created": "Mon, 3 Dec 2007 10:33:02 GMT", "version": "v1" }, { "created": "Tue, 4 Dec 2007 07:09:11 GMT", "version": "v2" }, { "created": "Thu, 13 Dec 2007 01:47:14 GMT", "version": "v3" } ]
2007-12-13
[ [ "Das", "C. R.", "" ], [ "Laperashvili", "L. V.", "" ] ]
In the present talk we have developed a concept of parallel ordinary (O) and mirror (M) worlds. We have shown that in the case of a broken mirror parity (MP), the evolutions of fine structure constants in the O- and M-worlds are not identical. It is assumed that E_6-unification inspired by superstring theory restores the broken MP at the scale \sim 10^{18} GeV, what unavoidably leads to the different E_6-breakdowns at this scale: E_6 \to SO(10)\times U(1)_Z - in the O-world, and E'_6 \to SU(6)'\times SU(2)'_Z - in the M-world. Considering only asymptotically free theories, we have presented the running of all the inverse gauge constants \alpha_i^{-1} in the one-loop approximation. Then a `quintessence' scenario is discussed for the model of accelerating universe. Such a scenario is related with an axion (`acceleron') of a new gauge group SU(2)'_Z which has a coupling constant g_Z extremely growing at the scale \Lambda_Z\sim 10^{-3} eV.
0812.4138
Tomoi Koide
T. Kodama and T. Koide
Memory Effects and Transport Coefficients for Non-Newtonian Fluids
6 pages, 2 figures, a talk given at Strangeness in Quark Matter 2008
J.Phys.G36:064063,2009
10.1088/0954-3899/36/6/064063
null
hep-ph cond-mat.stat-mech nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the roles of viscosity in relativistic fluid dynamics from the point of view of memory effects. Depending on the type of quantity to which the memory effect is applied, different terms appear in higher order corrections. We show that when the memory effect applies on the extensive quantities, the hydrodynamic equations of motion become non-singular. We further discuss the question of memory effect in the derivation of transport coefficients from a microscopic theory. We generalize the application of the Green-Kubo-Nakano (GKN) to calculate transport coefficients in the framework of projection operator formalism, and derive the general formula when the fluid is non-Newtonian.
[ { "created": "Mon, 22 Dec 2008 09:41:31 GMT", "version": "v1" } ]
2010-01-15
[ [ "Kodama", "T.", "" ], [ "Koide", "T.", "" ] ]
We discuss the roles of viscosity in relativistic fluid dynamics from the point of view of memory effects. Depending on the type of quantity to which the memory effect is applied, different terms appear in higher order corrections. We show that when the memory effect applies on the extensive quantities, the hydrodynamic equations of motion become non-singular. We further discuss the question of memory effect in the derivation of transport coefficients from a microscopic theory. We generalize the application of the Green-Kubo-Nakano (GKN) to calculate transport coefficients in the framework of projection operator formalism, and derive the general formula when the fluid is non-Newtonian.
0811.0393
Mathew McCaskey
Vernon Barger, Paul Langacker, Mathew McCaskey, Michael Ramsey-Musolf, Gabe Shaughnessy
Complex Singlet Extension of the Standard Model
30 pages, 10 figures, 1 table, PRD version
Phys.Rev.D79:015018,2009
10.1103/PhysRevD.79.015018
MADPH-08-1516
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze a simple extension of the Standard Model (SM) obtained by adding a complex singlet to the scalar sector (cxSM). We show that the cxSM can contain one or two viable cold dark matter candidates and analyze the conditions on the parameters of the scalar potential that yield the observed relic density. When the cxSM potential contains a global U(1) symmetry that is both softly and spontaneously broken, it contains both a viable dark matter candidate and the ingredients necessary for a strong first order electroweak phase transition as needed for electroweak baryogenesis. We also study the implications of the model for discovery of a Higgs boson at the Large Hadron Collider.
[ { "created": "Mon, 3 Nov 2008 21:05:44 GMT", "version": "v1" }, { "created": "Tue, 3 Feb 2009 21:09:20 GMT", "version": "v2" } ]
2009-02-03
[ [ "Barger", "Vernon", "" ], [ "Langacker", "Paul", "" ], [ "McCaskey", "Mathew", "" ], [ "Ramsey-Musolf", "Michael", "" ], [ "Shaughnessy", "Gabe", "" ] ]
We analyze a simple extension of the Standard Model (SM) obtained by adding a complex singlet to the scalar sector (cxSM). We show that the cxSM can contain one or two viable cold dark matter candidates and analyze the conditions on the parameters of the scalar potential that yield the observed relic density. When the cxSM potential contains a global U(1) symmetry that is both softly and spontaneously broken, it contains both a viable dark matter candidate and the ingredients necessary for a strong first order electroweak phase transition as needed for electroweak baryogenesis. We also study the implications of the model for discovery of a Higgs boson at the Large Hadron Collider.
1608.02529
Nicol\'as Mileo
Nicolas Mileo, Alejandro de la Puente, Alejandro Szynkman
Implications of a Electroweak Triplet Scalar Leptoquark on the Ultra-High Energy Neutrino Events at IceCube
30 pages, 12 figures, Updated LHC constraints; Figure 9 modified consistently. Added comment on interference effects
null
10.1007/JHEP11(2016)124
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the production of scalar leptoquarks at IceCube, in particular, a particle transforming as a triplet under the weak interaction. The existence of electroweak-triplet scalars is highly motivated by models of grand unification and also within radiative seesaw models for neutrino mass generation. In our framework, we extend the Standard Model by a single colored electroweak-triplet scalar leptoquark and analyze its implications on the excess of ultra-high energy neutrino events observed by the IceCube collaboration. We consider only couplings between the leptoquark to first generation leptons and quarks and carry out a statistical analysis to determine the parameters that best describe the IceCube data as well as set $95\%$ CL upper bounds. We analyze whether this study is still consistent with most up-to-date LHC data and various low energy observables.
[ { "created": "Mon, 8 Aug 2016 17:49:38 GMT", "version": "v1" }, { "created": "Wed, 28 Sep 2016 13:03:33 GMT", "version": "v2" } ]
2016-12-21
[ [ "Mileo", "Nicolas", "" ], [ "de la Puente", "Alejandro", "" ], [ "Szynkman", "Alejandro", "" ] ]
We study the production of scalar leptoquarks at IceCube, in particular, a particle transforming as a triplet under the weak interaction. The existence of electroweak-triplet scalars is highly motivated by models of grand unification and also within radiative seesaw models for neutrino mass generation. In our framework, we extend the Standard Model by a single colored electroweak-triplet scalar leptoquark and analyze its implications on the excess of ultra-high energy neutrino events observed by the IceCube collaboration. We consider only couplings between the leptoquark to first generation leptons and quarks and carry out a statistical analysis to determine the parameters that best describe the IceCube data as well as set $95\%$ CL upper bounds. We analyze whether this study is still consistent with most up-to-date LHC data and various low energy observables.
2004.04703
Sudhir Pandurang Rode
Sudhir Pandurang Rode, Partha Pratim Bhaduri, Amaresh Jaiswal and Ankhi Roy
Hierarchy of kinetic freeze-out parameters in low energy heavy-ion collisions
13 pages, 12 figures, published in Physical Review C
Phys. Rev. C 102, 054912 (2020)
10.1103/PhysRevC.102.054912
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the mass dependent hierarchy of kinetic freeze-out parameters of hadrons in low energy heavy-ion collisions. For this purpose, the transverse momentum and rapidity spectra of the identified hadrons produced in central Pb+Pb collisions, available at SPS energies ranging from $\rm E_{Lab}=20A-158A $ GeV, are analyzed within a generalized non boost-invariant blast wave model. We consider separate simultaneous fits for light hadrons ($\pi^{-}$, $K^{\pm}$) and heavy strange hadrons ($\Lambda$, $\bar{\Lambda}$, $\phi$, $\Xi^{\pm}$, $\Omega^{\pm}$), for which the transverse momentum spectra as well as rapidity spectra are available. We also perform a separate fit to transverse momentum spectra of charmonia ($J/\Psi$, $\Psi'$) at $158A $ GeV collisions. We find a clear mass dependent hierarchy in the fitted kinetic freeze-out parameters. Further, we study the rapidity spectra using analytical Landau flow solution for non-conformal systems. We find that the fitted value of sound velocity in the medium also shows a similar hierarchy.
[ { "created": "Thu, 9 Apr 2020 17:32:57 GMT", "version": "v1" }, { "created": "Tue, 24 Nov 2020 04:30:14 GMT", "version": "v2" } ]
2020-11-25
[ [ "Rode", "Sudhir Pandurang", "" ], [ "Bhaduri", "Partha Pratim", "" ], [ "Jaiswal", "Amaresh", "" ], [ "Roy", "Ankhi", "" ] ]
We study the mass dependent hierarchy of kinetic freeze-out parameters of hadrons in low energy heavy-ion collisions. For this purpose, the transverse momentum and rapidity spectra of the identified hadrons produced in central Pb+Pb collisions, available at SPS energies ranging from $\rm E_{Lab}=20A-158A $ GeV, are analyzed within a generalized non boost-invariant blast wave model. We consider separate simultaneous fits for light hadrons ($\pi^{-}$, $K^{\pm}$) and heavy strange hadrons ($\Lambda$, $\bar{\Lambda}$, $\phi$, $\Xi^{\pm}$, $\Omega^{\pm}$), for which the transverse momentum spectra as well as rapidity spectra are available. We also perform a separate fit to transverse momentum spectra of charmonia ($J/\Psi$, $\Psi'$) at $158A $ GeV collisions. We find a clear mass dependent hierarchy in the fitted kinetic freeze-out parameters. Further, we study the rapidity spectra using analytical Landau flow solution for non-conformal systems. We find that the fitted value of sound velocity in the medium also shows a similar hierarchy.
hep-ph/9602351
Wim Beenakker
W.Beenakker, F.A.Berends (conveners), E.N.Argyres, D.Bardin, A.Denner, S.Dittmaier, J.Hoogland, S.Jadach, R.Kleiss, Y.Kurihara, D.Lehner, G.Montagna, T.Munehisa, O.Nicrosini, T.Ohl, G.J. van Oldenborgh, C.G.Papadopoulos, G.Passarino, F.Piccinini, B.Pietrzyk, T.Riemann, Y.Shimizu, M.Skrzypek
WW Cross-sections and Distributions
61 pages, tar'ed gzip'ed uuencoded files, LaTeX, 4 Postscript figures. To appear in "Physics at LEP2", G.Altarelli and F.Zwirner eds., CERN Report 1996
null
null
null
hep-ph
null
We present the results obtained by the "WW Cross-sections and Distributions" working group during the CERN Workshop "Physics at LEP2" (1994/1995)
[ { "created": "Tue, 20 Feb 1996 16:30:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Beenakker", "W.", "", "conveners" ], [ "Berends", "F. A.", "", "conveners" ], [ "Argyres", "E. N.", "" ], [ "Bardin", "D.", "" ], [ "Denner", "A.", "" ], [ "Dittmaier", "S.", "" ], [ "Hoogland", "J.", ...
We present the results obtained by the "WW Cross-sections and Distributions" working group during the CERN Workshop "Physics at LEP2" (1994/1995)
1211.5295
Julian Heeck
Julian Heeck, Werner Rodejohann
Sterile Neutrino Anarchy
4 pages, 4 figures, matches published version
Phys.Rev.D87;037301,2013
10.1103/PhysRevD.87.037301
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lepton mixing, which requires physics beyond the Standard Model, is surprisingly compatible with a minimal, symmetryless and unbiased approach, called anarchy. This contrasts with highly involved flavor symmetry models. On the other hand, hints for light sterile neutrinos have emerged from a variety of independent experiments and observations. If confirmed, their existence would represent a groundbreaking discovery, calling for a theoretical interpretation. We discuss anarchy in the two-neutrino eV-scale seesaw framework. The distributions of mixing angles and masses according to anarchy are in agreement with global fits for the active and sterile neutrino parameters. Our minimal and economical scenario predicts the absence of neutrinoless double beta decay and one vanishing neutrino mass, and can therefore be tested in future experiments.
[ { "created": "Thu, 22 Nov 2012 14:22:44 GMT", "version": "v1" }, { "created": "Thu, 7 Feb 2013 09:17:29 GMT", "version": "v2" } ]
2013-02-08
[ [ "Heeck", "Julian", "" ], [ "Rodejohann", "Werner", "" ] ]
Lepton mixing, which requires physics beyond the Standard Model, is surprisingly compatible with a minimal, symmetryless and unbiased approach, called anarchy. This contrasts with highly involved flavor symmetry models. On the other hand, hints for light sterile neutrinos have emerged from a variety of independent experiments and observations. If confirmed, their existence would represent a groundbreaking discovery, calling for a theoretical interpretation. We discuss anarchy in the two-neutrino eV-scale seesaw framework. The distributions of mixing angles and masses according to anarchy are in agreement with global fits for the active and sterile neutrino parameters. Our minimal and economical scenario predicts the absence of neutrinoless double beta decay and one vanishing neutrino mass, and can therefore be tested in future experiments.
1001.3236
Jochum van der Bij
J.J. van der Bij
Gravitational anomaly and fundamental forces
Contribution to the 2nd School and Workshop on Quantum Gravity and Quantum Geometry. Corfu, september 13-20 2009. 10 pages
null
10.1007/s10714-010-1053-x
Freiburg-PHENO-2010-005
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present an argument, based on the topology of the universe, why there are three generations of fermions. The argument implies a preferred gauge group of SU(5), but with SO(10) representations of the fermions. The breaking pattern SU(5) to SU(3)xSU(2)xU(1) is preferred over the pattern SU(5) to SU(4)xU(1). On the basis of the argument one expects an asymmetry in the early universe microwave data, which might have been detected already.
[ { "created": "Tue, 19 Jan 2010 09:38:57 GMT", "version": "v1" } ]
2015-05-18
[ [ "van der Bij", "J. J.", "" ] ]
I present an argument, based on the topology of the universe, why there are three generations of fermions. The argument implies a preferred gauge group of SU(5), but with SO(10) representations of the fermions. The breaking pattern SU(5) to SU(3)xSU(2)xU(1) is preferred over the pattern SU(5) to SU(4)xU(1). On the basis of the argument one expects an asymmetry in the early universe microwave data, which might have been detected already.
1810.09429
Bogdan A. Dobrescu
Bogdan A. Dobrescu, Robert M. Harris and Joshua Isaacson
Ultraheavy resonances at the LHC: beyond the QCD background
41 pages, 15 figures
null
null
Fermilab-PUB-18-561-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the theory and some experimental hints of ultraheavy resonances at the LHC. The production of an ultraheavy narrow particle may have a larger rate than the QCD background even when the final state includes only hadronic jets. We consider two classes of models that lead to 4-jet signals. In the first class a diquark scalar decays into two vectorlike quarks. In the second one a coloron decays into two color-octet scalars or into a pair of vectorlike quarks. We show that a diquark as heavy as 11.5 TeV, or a coloron as heavy as 8.5 TeV may be discovered at the LHC. We point out that a CMS 4-jet event may be due to an 8 TeV resonance decaying into two secondary particles, each with a mass of 1.8 TeV. We find that the QCD background with a 4-jet mass and dijet masses that equal or exceed those of the CMS event is approximately $5\times 10^{-5}$ events in 78 fb$^{-1}$ of data, while the diquark signal could have easily produced that event. The diquark also decays directly into two jets, which may be the origin of some of the three other events of mass near 8 TeV observed by ATLAS and CMS.
[ { "created": "Mon, 22 Oct 2018 17:55:47 GMT", "version": "v1" } ]
2018-10-23
[ [ "Dobrescu", "Bogdan A.", "" ], [ "Harris", "Robert M.", "" ], [ "Isaacson", "Joshua", "" ] ]
We study the theory and some experimental hints of ultraheavy resonances at the LHC. The production of an ultraheavy narrow particle may have a larger rate than the QCD background even when the final state includes only hadronic jets. We consider two classes of models that lead to 4-jet signals. In the first class a diquark scalar decays into two vectorlike quarks. In the second one a coloron decays into two color-octet scalars or into a pair of vectorlike quarks. We show that a diquark as heavy as 11.5 TeV, or a coloron as heavy as 8.5 TeV may be discovered at the LHC. We point out that a CMS 4-jet event may be due to an 8 TeV resonance decaying into two secondary particles, each with a mass of 1.8 TeV. We find that the QCD background with a 4-jet mass and dijet masses that equal or exceed those of the CMS event is approximately $5\times 10^{-5}$ events in 78 fb$^{-1}$ of data, while the diquark signal could have easily produced that event. The diquark also decays directly into two jets, which may be the origin of some of the three other events of mass near 8 TeV observed by ATLAS and CMS.
hep-ph/9610440
Nils Tornqvist
Nils A. Tornqvist (University of Helsinki)
Breaking Flavour Symmetry Spontaneously
Major revisions in text, 12 pages, RevTeX, 5 Figures
Phys.Lett. B406 (1997) 70-75
10.1016/S0370-2693(97)00681-3
null
hep-ph
null
A new mechanism for spontaneous breaking of flavour symmetry is demonstrated. An exactly flavour symmetric model with degenerate bare nonets and with sufficiently strong tri-linear meson couplings is shown to lead to self-consistency equations which are unstable. Instead there exists a stable solution, which break flavour symmetry spontaneously in the mass spectrum. For a C-degenerate meson spectrum the stable mass spectrum obeys the Okubo-Zweig-Iizuka (OZI) rule and the approximate equal spacing rule.
[ { "created": "Tue, 22 Oct 1996 09:58:32 GMT", "version": "v1" }, { "created": "Fri, 7 Mar 1997 11:54:30 GMT", "version": "v2" } ]
2009-10-30
[ [ "Tornqvist", "Nils A.", "", "University of Helsinki" ] ]
A new mechanism for spontaneous breaking of flavour symmetry is demonstrated. An exactly flavour symmetric model with degenerate bare nonets and with sufficiently strong tri-linear meson couplings is shown to lead to self-consistency equations which are unstable. Instead there exists a stable solution, which break flavour symmetry spontaneously in the mass spectrum. For a C-degenerate meson spectrum the stable mass spectrum obeys the Okubo-Zweig-Iizuka (OZI) rule and the approximate equal spacing rule.
1307.0884
Fernando Rossi Torres
F. Rossi-Torres
Probing Lorentz Invariance Violation with Neutrino Factories
8 pages, 6 figures. Several improvements in the text. New references added. Improvements in the discussions and conclusions
J.Phys. G42 (2015) 5, 055003
10.1088/0954-3899/42/5/055003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we show the modification in the number of neutrino events ($\nu_\mu+\bar\nu_\mu$) caused by Lorentz Invariant Violation (LIV), $\sigma=5\times 10^{-24}$ and $10^{-23}$, in neutrino oscillation for a neutrino factory at a distance of 7500 km. The momentum of the muons can vary from 10-50 GeV and we consider $2\times 10^{20}$ decays per year. The modifications in the number of events caused by this $\sigma$ LIV parameter could be a strong signal of new physics in a future neutrino factory.
[ { "created": "Wed, 3 Jul 2013 00:10:28 GMT", "version": "v1" }, { "created": "Mon, 6 Jan 2014 16:05:49 GMT", "version": "v2" }, { "created": "Mon, 23 Mar 2015 11:49:23 GMT", "version": "v3" } ]
2015-03-24
[ [ "Rossi-Torres", "F.", "" ] ]
In this article we show the modification in the number of neutrino events ($\nu_\mu+\bar\nu_\mu$) caused by Lorentz Invariant Violation (LIV), $\sigma=5\times 10^{-24}$ and $10^{-23}$, in neutrino oscillation for a neutrino factory at a distance of 7500 km. The momentum of the muons can vary from 10-50 GeV and we consider $2\times 10^{20}$ decays per year. The modifications in the number of events caused by this $\sigma$ LIV parameter could be a strong signal of new physics in a future neutrino factory.
1112.4680
Daniel Almeida Fagundes
D. A. Fagundes, E. G. S. Luna, M. J. Menon, A. A. Natale
Aspects of a dynamical gluon mass approach to elastic hadron scattering at LHC
19 pages, 7 figures, 5 tables. Discussion extended, references added, typos corrected, to be published in Nucl. Phys. A
null
10.1016/j.nuclphysa.2012.05.002
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss how the main features of the recent LHC data on elastic scattering can be described by a QCD-inspired formalism with a dynamical infrared mass scale. For this purpose new developments on a dynamical gluon mass approach are reported, with emphasis on a method to estimate uncertainty bounds in the predictions for the high-energy scattering observables. We investigate the effects due to the correlations among the fixed and free parameters involved and show that the band of predictions are consistent with the recent data from the TOTEM experiment, including the forward quantities and the differential cross section up to the dip position.
[ { "created": "Tue, 20 Dec 2011 13:38:32 GMT", "version": "v1" }, { "created": "Thu, 10 May 2012 17:36:14 GMT", "version": "v2" } ]
2015-06-03
[ [ "Fagundes", "D. A.", "" ], [ "Luna", "E. G. S.", "" ], [ "Menon", "M. J.", "" ], [ "Natale", "A. A.", "" ] ]
We discuss how the main features of the recent LHC data on elastic scattering can be described by a QCD-inspired formalism with a dynamical infrared mass scale. For this purpose new developments on a dynamical gluon mass approach are reported, with emphasis on a method to estimate uncertainty bounds in the predictions for the high-energy scattering observables. We investigate the effects due to the correlations among the fixed and free parameters involved and show that the band of predictions are consistent with the recent data from the TOTEM experiment, including the forward quantities and the differential cross section up to the dip position.
hep-ph/9602350
null
S. Dimopoulos and G.F. Giudice
Macroscopic Forces from Supersymmetry
17 pages, 2 figures
Phys.Lett. B379 (1996) 105-114
10.1016/0370-2693(96)00390-5
null
hep-ph hep-th
null
We argue that theories in which supersymmetry breaking originates at low energies often contain scalar particles that mediate coherent gravitational strength forces at distances less than a cm. We estimate the strength and range of these forces in several cases. Present limits on such forces are inadequate. However new techniques, such as those based on small cryogenic mechanical oscillators, may improve the present limits by ten orders of magnitude or discover new forces as weak as 1 \% of gravity at distances down to 40 microns.
[ { "created": "Tue, 20 Feb 1996 15:43:33 GMT", "version": "v1" } ]
2009-10-28
[ [ "Dimopoulos", "S.", "" ], [ "Giudice", "G. F.", "" ] ]
We argue that theories in which supersymmetry breaking originates at low energies often contain scalar particles that mediate coherent gravitational strength forces at distances less than a cm. We estimate the strength and range of these forces in several cases. Present limits on such forces are inadequate. However new techniques, such as those based on small cryogenic mechanical oscillators, may improve the present limits by ten orders of magnitude or discover new forces as weak as 1 \% of gravity at distances down to 40 microns.
2211.13825
Federico Compagnin
Federico Compagnin, Stefano Profumo, Nicolao Fornengo
MeV Dark Matter with MeV Dark Photons in Abelian Kinetic Mixing Theories
null
null
10.1088/1475-7516/2023/03/061
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider the cosmology and phenomenology of a dark photon portal to a simple dark sector consisting of a single, light, fermionic dark matter particle species with mass in the MeV range. We entertain three possible kinetic mixing structures of a new Abelian gauge group U(1)$_{\text{dark}}$ with the visible sector through U(1)$_{\text{e.m.}}$, U(1)$_{\text{Y}}$ and T[SU(2)$_{\text{L}}$]. We assume the dark photon to be massive and around the MeV scale, thus close to the mass scale of the dark matter candidate. We compute the dark matter relic density via freeze-out and freeze-in, entertaining the additional possibilities of (i) a late inflationary period that could dilute the dark matter yield of heavy candidates, and (ii) additional production modes, for models with under-abundant thermal production. We explore the parameter space compatible with a variety of experimental and astrophysical bounds, and discuss prospects for discovery with new CMB probes and MeV gamma-ray telescopes.
[ { "created": "Thu, 24 Nov 2022 23:33:13 GMT", "version": "v1" } ]
2023-04-12
[ [ "Compagnin", "Federico", "" ], [ "Profumo", "Stefano", "" ], [ "Fornengo", "Nicolao", "" ] ]
We consider the cosmology and phenomenology of a dark photon portal to a simple dark sector consisting of a single, light, fermionic dark matter particle species with mass in the MeV range. We entertain three possible kinetic mixing structures of a new Abelian gauge group U(1)$_{\text{dark}}$ with the visible sector through U(1)$_{\text{e.m.}}$, U(1)$_{\text{Y}}$ and T[SU(2)$_{\text{L}}$]. We assume the dark photon to be massive and around the MeV scale, thus close to the mass scale of the dark matter candidate. We compute the dark matter relic density via freeze-out and freeze-in, entertaining the additional possibilities of (i) a late inflationary period that could dilute the dark matter yield of heavy candidates, and (ii) additional production modes, for models with under-abundant thermal production. We explore the parameter space compatible with a variety of experimental and astrophysical bounds, and discuss prospects for discovery with new CMB probes and MeV gamma-ray telescopes.
1708.08625
T. Lappi
T. Lappi, S. Schlichting
Linearly polarized gluons and axial charge fluctuations in the Glasma
36 pages, 3 figures
Phys. Rev. D 97, 034034 (2018)
10.1103/PhysRevD.97.034034
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate of the one- and two-point correlation functions of the energy density and the divergence of the Chern-Simons current in the nonequilibrium Glasma state formed in a high-energy nuclear collision. We show that the latter depends on the difference of the total and linearly polarized gluon transverse momentum distributions. Since the divergence of the Chern-Simons current provides the source of axial charge, we infer information about the statistical properties of axial charge production at early times. We further develop a simple phenomenological model to characterize axial charge distributions in terms of distributions of the energy density.
[ { "created": "Tue, 29 Aug 2017 07:58:09 GMT", "version": "v1" } ]
2018-03-07
[ [ "Lappi", "T.", "" ], [ "Schlichting", "S.", "" ] ]
We calculate of the one- and two-point correlation functions of the energy density and the divergence of the Chern-Simons current in the nonequilibrium Glasma state formed in a high-energy nuclear collision. We show that the latter depends on the difference of the total and linearly polarized gluon transverse momentum distributions. Since the divergence of the Chern-Simons current provides the source of axial charge, we infer information about the statistical properties of axial charge production at early times. We further develop a simple phenomenological model to characterize axial charge distributions in terms of distributions of the energy density.
2405.16210
Muhammad Omar Nadeem Mr.
Muhammad Omar Nadeem
Scalar Leptoquark Contribution to Two Photon Elastic Scattering
16 pages, 10 figures
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We study the contribution of Scalar Leptoquark (SLQ) loops to the two photon scattering cross section at high energies. The leading order helicity amplitudes are discussed at coupling O(e4) for Standard Model (SM) fermions, weak bosons and SLQs. Helicity amplitudes for the different types of loops are calculated for photon center of mass energies being much higher than weak boson mass scale but still much lower than the predicted Leptoquark mass scales. Finally, the cross section due to the SLQ loops is presented in conjunction with the known SM contribution.
[ { "created": "Sat, 25 May 2024 12:46:08 GMT", "version": "v1" }, { "created": "Wed, 12 Jun 2024 16:06:48 GMT", "version": "v2" } ]
2024-06-13
[ [ "Nadeem", "Muhammad Omar", "" ] ]
We study the contribution of Scalar Leptoquark (SLQ) loops to the two photon scattering cross section at high energies. The leading order helicity amplitudes are discussed at coupling O(e4) for Standard Model (SM) fermions, weak bosons and SLQs. Helicity amplitudes for the different types of loops are calculated for photon center of mass energies being much higher than weak boson mass scale but still much lower than the predicted Leptoquark mass scales. Finally, the cross section due to the SLQ loops is presented in conjunction with the known SM contribution.
hep-ph/9806254
Nils Tornqvist
Nils A. Tornqvist (University of Helsinki)
Predicting the Pion and Eta Masses as Quantum Corrections without Quark Masses
Removed paper to be rewritten
null
null
null
hep-ph hep-th nucl-th
null
This paper is removed because it used an approximation, which alters some of the conclusions. Another paper will be written in the near future.
[ { "created": "Thu, 4 Jun 1998 10:41:46 GMT", "version": "v1" }, { "created": "Fri, 10 Jul 1998 13:32:03 GMT", "version": "v2" }, { "created": "Fri, 28 Aug 1998 13:16:12 GMT", "version": "v3" } ]
2007-05-23
[ [ "Tornqvist", "Nils A.", "", "University of Helsinki" ] ]
This paper is removed because it used an approximation, which alters some of the conclusions. Another paper will be written in the near future.
hep-ph/0104193
Nikita Agasian
N.O.Agasian (ITEP, Moscow)
Low temperature relation for the trace of the energy-momentum tensor in QCD with light quarks
RevTeX, 4 pages, no figures
JETP Lett. 74 (2001) 353-356
10.1134/1.1427120
null
hep-ph
null
It is shown that the temperature derivatives of the anomalous and normal (quark massive term) contributions to the trace of the energy-momentum tensor in QCD are equal to each other in the low temperature region. The physical consequences of this relation are discussed.
[ { "created": "Thu, 19 Apr 2001 14:55:59 GMT", "version": "v1" }, { "created": "Mon, 23 Apr 2001 12:56:55 GMT", "version": "v2" } ]
2009-11-07
[ [ "Agasian", "N. O.", "", "ITEP, Moscow" ] ]
It is shown that the temperature derivatives of the anomalous and normal (quark massive term) contributions to the trace of the energy-momentum tensor in QCD are equal to each other in the low temperature region. The physical consequences of this relation are discussed.
2311.13640
Yann Gouttenoire Dr
Yann Gouttenoire
Primordial Black Holes from Conformal Higgs
Check of validity of beta-parameterisation of the tunnelling rate, discussions and Refs added. Software program to calculate bounce action and nucleation temperature available on github (https://github.com/YannGou/CCBounce.git). Matches version published in PLB
null
10.1016/j.physletb.2024.138800
null
hep-ph astro-ph.CO gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
Scale-invariant extensions of the electroweak theory are not only attractive because they can dynamically generate the weak scale, but also due to their role in facilitating supercooled first-order phase transitions. We study the minimal scale-invariant $U(1)_{\rm D}$ extension of the standard model and show that Primordial Black Holes (PBHs) can be abundantly produced. The mass of these PBHs is bounded from above by that of the moon due to QCD catalysis limiting the amount of supercooling. Lunar-mass PBHs, which are produced for dark Higgs vev $v_\phi\simeq 20~\rm TeV$, correspond to the best likelihood to explain the HSC lensing anomaly. For $v_\phi\gtrsim 400~\rm TeV$, the model can explain hundred per cent of dark matter. At even larger hierarchy of scales, it can contribute to the $511~\rm keV$ line. While the gravitational wave (GW) signal produced by the HSC anomaly interpretation is large and detectable by LISA above astrophysical foreground, the dark matter interpretation in terms of PBHs can not be entirely probed by future GW detection. This is due to the dilution of the signal by the entropy injected during the decay of the long-lived $U(1)_{\rm D}$ scalar. This extended lifetime is a natural consequence of the large hierarchy of scales.
[ { "created": "Wed, 22 Nov 2023 19:00:02 GMT", "version": "v1" }, { "created": "Fri, 8 Dec 2023 17:16:34 GMT", "version": "v2" }, { "created": "Fri, 21 Jun 2024 11:06:40 GMT", "version": "v3" } ]
2024-06-24
[ [ "Gouttenoire", "Yann", "" ] ]
Scale-invariant extensions of the electroweak theory are not only attractive because they can dynamically generate the weak scale, but also due to their role in facilitating supercooled first-order phase transitions. We study the minimal scale-invariant $U(1)_{\rm D}$ extension of the standard model and show that Primordial Black Holes (PBHs) can be abundantly produced. The mass of these PBHs is bounded from above by that of the moon due to QCD catalysis limiting the amount of supercooling. Lunar-mass PBHs, which are produced for dark Higgs vev $v_\phi\simeq 20~\rm TeV$, correspond to the best likelihood to explain the HSC lensing anomaly. For $v_\phi\gtrsim 400~\rm TeV$, the model can explain hundred per cent of dark matter. At even larger hierarchy of scales, it can contribute to the $511~\rm keV$ line. While the gravitational wave (GW) signal produced by the HSC anomaly interpretation is large and detectable by LISA above astrophysical foreground, the dark matter interpretation in terms of PBHs can not be entirely probed by future GW detection. This is due to the dilution of the signal by the entropy injected during the decay of the long-lived $U(1)_{\rm D}$ scalar. This extended lifetime is a natural consequence of the large hierarchy of scales.
1210.8307
Swapan Majhi
Swapan Majhi
QCD corrections to excited lepton (pair) production at LHC
15 pages, 9 figures. modified the text, some typos corrected, improved version submitted
Phys. Rev. D 88, 074028 (2013)
10.1103/PhysRevD.88.074028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider excited lepton ($\bar{l^*}l {\rm or} \bar{l^*}l^*$) production in the context of effective theories with being four-fermion contact interaction at LHC. We also consider the two body decay mode of excited lepton ($l^*$) to standard model fermion($l$) and a gauge boson $V(\equiv \gamma,Z,W)$. We have performed next-to-leading order (NLO) QCD corrections to this process. In spite of non-renormalizable nature of the interaction, the higher order QCD corrections are possible and meaningful. We have shown that these corrections can be substantial and significant. By considering the issue of scale dependence, it is shown that the scale dependence of the NLO cross sections are greatly reduced as compare to leading order (LO) cross section.
[ { "created": "Wed, 31 Oct 2012 12:17:43 GMT", "version": "v1" }, { "created": "Tue, 6 Nov 2012 07:57:54 GMT", "version": "v2" }, { "created": "Fri, 8 Feb 2013 09:16:47 GMT", "version": "v3" }, { "created": "Mon, 9 Mar 2015 13:33:17 GMT", "version": "v4" } ]
2015-03-10
[ [ "Majhi", "Swapan", "" ] ]
We consider excited lepton ($\bar{l^*}l {\rm or} \bar{l^*}l^*$) production in the context of effective theories with being four-fermion contact interaction at LHC. We also consider the two body decay mode of excited lepton ($l^*$) to standard model fermion($l$) and a gauge boson $V(\equiv \gamma,Z,W)$. We have performed next-to-leading order (NLO) QCD corrections to this process. In spite of non-renormalizable nature of the interaction, the higher order QCD corrections are possible and meaningful. We have shown that these corrections can be substantial and significant. By considering the issue of scale dependence, it is shown that the scale dependence of the NLO cross sections are greatly reduced as compare to leading order (LO) cross section.
0807.4289
Sandhya Choubey
Sandhya Choubey, Werner Rodejohann, Probir Roy
Phenomenological consequences of four zero neutrino Yukawa textures
25 pages, Typo in Eq. (10) and the Tables corrected
Nucl.Phys.B808:272-291,2009; Erratum-ibid.818:136,2009
10.1016/j.nuclphysb.2008.09.031 10.1016/j.nuclphysb.2009.04.021
HRI-P-08-07-003
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For type I seesaw and in the basis where the charged lepton and heavy right-handed neutrino mass matrices are real and diagonal, four has been shown to be the maximum number of zeros allowed in the neutrino Yukawa coupling matrix $Y_\nu$. These four zero textures have been classified into two distinct categories. We investigate certain phenomenological consequences of these textures within a supersymmetric framework. This is done by using conditions implied on elements of the neutrino Majorana mass matrix for textures of each category in $Y_\nu$. These conditions turn out to be stable under radiative corrections. Including the effective mass, which appears in neutrinoless double beta decay, along with the usual neutrino masses, mixing angles and phases, it is shown analytically and through scatter plots how restricted regions in the seesaw parameter space are selected by these conditions. We also make consequential statements on the yet unobserved radiative lepton flavor violating decays such as $\mu \to e \gamma$. All these decay amplitudes are proportional to the moduli of entries of the neutrino Majorana mass matrix. We also show under which conditions the low energy CP violation, showing up in neutrino oscillations, is directly linked to the CP violation required for producing successful flavor dependent and flavor independent lepton asymmetries during leptogenesis.
[ { "created": "Sun, 27 Jul 2008 12:06:52 GMT", "version": "v1" }, { "created": "Wed, 17 Sep 2008 14:53:10 GMT", "version": "v2" }, { "created": "Tue, 21 Apr 2009 17:14:13 GMT", "version": "v3" } ]
2009-08-10
[ [ "Choubey", "Sandhya", "" ], [ "Rodejohann", "Werner", "" ], [ "Roy", "Probir", "" ] ]
For type I seesaw and in the basis where the charged lepton and heavy right-handed neutrino mass matrices are real and diagonal, four has been shown to be the maximum number of zeros allowed in the neutrino Yukawa coupling matrix $Y_\nu$. These four zero textures have been classified into two distinct categories. We investigate certain phenomenological consequences of these textures within a supersymmetric framework. This is done by using conditions implied on elements of the neutrino Majorana mass matrix for textures of each category in $Y_\nu$. These conditions turn out to be stable under radiative corrections. Including the effective mass, which appears in neutrinoless double beta decay, along with the usual neutrino masses, mixing angles and phases, it is shown analytically and through scatter plots how restricted regions in the seesaw parameter space are selected by these conditions. We also make consequential statements on the yet unobserved radiative lepton flavor violating decays such as $\mu \to e \gamma$. All these decay amplitudes are proportional to the moduli of entries of the neutrino Majorana mass matrix. We also show under which conditions the low energy CP violation, showing up in neutrino oscillations, is directly linked to the CP violation required for producing successful flavor dependent and flavor independent lepton asymmetries during leptogenesis.
hep-ph/0205229
Rainer Kuehne
Rainer W. Kuhne
Review of Quantum Electromagnetodynamics
9 pages, latex
Electromagn.Phenom.3N9:86-91,2003
null
null
hep-ph
null
Several years ago, I suggested a quantum field theory which has many attractive features. (1) It can explain the quantization of electric charge. (2) It describes symmetrized Maxwell equations. (3) It is manifestly covariant. (4) It describes local four-potentials. (5) It avoids the unphysical Dirac string. Here I will review the ideas which led to my model of magnetic monopoles including my prediction of the second kind of electromagnetic radiation. I will present also the mathematical formalism. Moreover I will suggest an experiment to verify the second kind of electromagnetic radiation and point out a possible observation of this radiation by August Kundt in 1885. Finally, I will list the many and far-reaching consequences, if this radiation will be confirmed by future experiments.
[ { "created": "Tue, 21 May 2002 14:11:48 GMT", "version": "v1" } ]
2009-08-05
[ [ "Kuhne", "Rainer W.", "" ] ]
Several years ago, I suggested a quantum field theory which has many attractive features. (1) It can explain the quantization of electric charge. (2) It describes symmetrized Maxwell equations. (3) It is manifestly covariant. (4) It describes local four-potentials. (5) It avoids the unphysical Dirac string. Here I will review the ideas which led to my model of magnetic monopoles including my prediction of the second kind of electromagnetic radiation. I will present also the mathematical formalism. Moreover I will suggest an experiment to verify the second kind of electromagnetic radiation and point out a possible observation of this radiation by August Kundt in 1885. Finally, I will list the many and far-reaching consequences, if this radiation will be confirmed by future experiments.
2404.08508
Maria Ubiali Prof
Maria Ubiali
Parton Distribution Functions and Their Impact on Precision of the Current Theory Calculations
Contribution to the Proceedings of the XXX Cracow Epiphany Conference on Precision Physics at High Energy Colliders, dedicated to the memory of Staszek Jadach
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The unprecedented precision of experimental measurements at the Large Hadron Collider (LHC) and the increased statistics that will be reached in the High-Luminosity phase of the LHC (HL-LHC) are pushing the phenomenology community to a new precision frontier, in which new challenges present themselves and new questions arise. A key ingredients of theoretical predictions at hadron colliders are the Parton Distribution Functions (PDFs) of the proton. This contribution highlights some of the new developments in the determination of PDFs from a global set of experimental data, from approximate N3LO PDFs and the inclusion of theory uncertainties in PDF fits, to the realisation of the non trivial interplay between parton densities at large-x and possible signals of New Physics in high energy tails of the distributions, which highlights the synergy between high energy and low energy experimental programs.
[ { "created": "Fri, 12 Apr 2024 14:44:11 GMT", "version": "v1" } ]
2024-04-15
[ [ "Ubiali", "Maria", "" ] ]
The unprecedented precision of experimental measurements at the Large Hadron Collider (LHC) and the increased statistics that will be reached in the High-Luminosity phase of the LHC (HL-LHC) are pushing the phenomenology community to a new precision frontier, in which new challenges present themselves and new questions arise. A key ingredients of theoretical predictions at hadron colliders are the Parton Distribution Functions (PDFs) of the proton. This contribution highlights some of the new developments in the determination of PDFs from a global set of experimental data, from approximate N3LO PDFs and the inclusion of theory uncertainties in PDF fits, to the realisation of the non trivial interplay between parton densities at large-x and possible signals of New Physics in high energy tails of the distributions, which highlights the synergy between high energy and low energy experimental programs.
1503.05505
Michel Tytgat
Nadir Daci, Isabelle De Bruyn, Steven Lowette, Michel H.G. Tytgat and Bryan Zaldivar
Simplified SIMPs and the LHC
18 pages, 7 figures
null
10.1007/JHEP11(2015)108
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existence of Dark Matter (DM) in the form of Strongly Interacting Massive Particles (SIMPs) may be motivated by astrophysical observations that challenge the classical Cold DM scenario. Other observations greatly constrain, but do not completely exclude, the SIMP alternative. The signature of SIMPs at the LHC may consist of neutral, hadron-like, trackless jets produced in pairs. We show that the absence of charged content can provide a very efficient tool to suppress dijet backgrounds at the LHC, thus enhancing the sensitivity to a potential SIMP signal. We illustrate this using a simplified SIMP model and present a detailed feasibility study based on simulations, including a dedicated detector response parametrization. We evaluate the expected sensitivity to various signal scenarios and tentatively consider the exclusion limits on the SIMP elastic cross section with nucleons.
[ { "created": "Wed, 18 Mar 2015 17:35:03 GMT", "version": "v1" } ]
2016-01-20
[ [ "Daci", "Nadir", "" ], [ "De Bruyn", "Isabelle", "" ], [ "Lowette", "Steven", "" ], [ "Tytgat", "Michel H. G.", "" ], [ "Zaldivar", "Bryan", "" ] ]
The existence of Dark Matter (DM) in the form of Strongly Interacting Massive Particles (SIMPs) may be motivated by astrophysical observations that challenge the classical Cold DM scenario. Other observations greatly constrain, but do not completely exclude, the SIMP alternative. The signature of SIMPs at the LHC may consist of neutral, hadron-like, trackless jets produced in pairs. We show that the absence of charged content can provide a very efficient tool to suppress dijet backgrounds at the LHC, thus enhancing the sensitivity to a potential SIMP signal. We illustrate this using a simplified SIMP model and present a detailed feasibility study based on simulations, including a dedicated detector response parametrization. We evaluate the expected sensitivity to various signal scenarios and tentatively consider the exclusion limits on the SIMP elastic cross section with nucleons.
hep-ph/0702275
Stefan Recksiegel
Robert Fleischer, Stefan Recksiegel and Felix Schwab
On Puzzles and Non-Puzzles in B -> pi pi, pi K Decays
12 pages, 4 figures. References added, to appear in EPJC
Eur.Phys.J.C51:55-61,2007
10.1140/epjc/s10052-007-0277-8
CERN-PH-TH/2007-044, TUM-HEP-663/07, UAB-FT-627
hep-ph
null
Recently, we have seen interesting progress in the exploration of CP violation in B^0_d -> pi^+ pi^-: the measurements of mixing-induced CP violation by the BaBar and Belle collaborations are now in good agreement with each other, whereas the picture of direct CP violation is still unclear. Using the branching ratio and direct CP asymmetry of B^0_d -> pi^- K^+, this situation can be clarified. We predict A_CP^dir(B_d -> pi^+ pi^-) = -0.24+-0.04, which favours the BaBar result, and extract gamma=(70.0^{+3.8}_{-4.3})deg, which agrees with the unitarity triangle fits. Extending our analysis to other B -> pi K modes and B^0_s -> K^+ K^- with the help of the SU(3) flavour symmetry and plausible dynamical assumptions, we find that all observables with colour-suppressed electroweak penguin contributions are measured in excellent agreement with the Standard Model. As far as the ratios R_{c,n} of the charged and neutral B -> pi K branching ratios are concerned, which are sizeably affected by electroweak penguin contributions, our Standard-Model predictions have almost unchanged central values, but significantly reduced errors. Since the new data have moved quite a bit towards these results, the "B -> pi K puzzle" for the CP-conserving quantities has been significantly reduced. However, the mixing-induced CP violation of B^0_d -> pi^0 K_S does look puzzling; if confirmed by future measurements, this effect could be accommodated through a modified electroweak penguin sector with a large CP-violating new-physics phase. Finally, we point out that the established difference between the direct CP asymmetries of B^+- -> pi^0 K^+- and B_d -> pi^-+ K^+- appears to be generated by hadronic and not by new physics.
[ { "created": "Tue, 27 Feb 2007 13:55:46 GMT", "version": "v1" }, { "created": "Fri, 9 Mar 2007 18:03:48 GMT", "version": "v2" } ]
2008-11-26
[ [ "Fleischer", "Robert", "" ], [ "Recksiegel", "Stefan", "" ], [ "Schwab", "Felix", "" ] ]
Recently, we have seen interesting progress in the exploration of CP violation in B^0_d -> pi^+ pi^-: the measurements of mixing-induced CP violation by the BaBar and Belle collaborations are now in good agreement with each other, whereas the picture of direct CP violation is still unclear. Using the branching ratio and direct CP asymmetry of B^0_d -> pi^- K^+, this situation can be clarified. We predict A_CP^dir(B_d -> pi^+ pi^-) = -0.24+-0.04, which favours the BaBar result, and extract gamma=(70.0^{+3.8}_{-4.3})deg, which agrees with the unitarity triangle fits. Extending our analysis to other B -> pi K modes and B^0_s -> K^+ K^- with the help of the SU(3) flavour symmetry and plausible dynamical assumptions, we find that all observables with colour-suppressed electroweak penguin contributions are measured in excellent agreement with the Standard Model. As far as the ratios R_{c,n} of the charged and neutral B -> pi K branching ratios are concerned, which are sizeably affected by electroweak penguin contributions, our Standard-Model predictions have almost unchanged central values, but significantly reduced errors. Since the new data have moved quite a bit towards these results, the "B -> pi K puzzle" for the CP-conserving quantities has been significantly reduced. However, the mixing-induced CP violation of B^0_d -> pi^0 K_S does look puzzling; if confirmed by future measurements, this effect could be accommodated through a modified electroweak penguin sector with a large CP-violating new-physics phase. Finally, we point out that the established difference between the direct CP asymmetries of B^+- -> pi^0 K^+- and B_d -> pi^-+ K^+- appears to be generated by hadronic and not by new physics.
2402.16963
Gui-Jun Ding
Gui-Jun Ding, Jose W.F. Valle
The symmetry approach to quark and lepton masses and mixing
172 pages, 41 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model lacks an organizing principle to describe quark and lepton ``flavours''. We review the impact of neutrino oscillation experiments, which show that leptons mix very differently from quarks, placing a major challenge, but also providing a key input to the flavour puzzle. We briefly sketch the seesaw and ``scotogenic'' approaches to neutrino mass, the latter including also WIMP dark matter. We discuss the limitations of popular neutrino mixing patterns and examine the possibility that they arise from symmetry, giving a bottom-up approach to residual flavour and CP symmetries. We show how family and/or CP symmetries can generate novel viable and predictive mixing patterns. We review the model-independent ways to predict lepton mixing and test both mixing predictions as well as mass sum rules. We also discuss UV-complete flavour theories in four and more space-time dimensions, and their predictions. Benchmarks given include an $A_4$ scotogenic construction with trimaximal mixing pattern TM2. Higher-dimensional completions are also reviewed, such as 5-D warped flavordynamics. We present a $T^\prime$ warped flavordynamics theory with TM1 mixing pattern, detectable neutrinoless double beta decay rates and providing a very good fit of flavour observables, including quarks. We also review how 6-D orbifolds offer a way to determine the structure of the 4-D family symmetry from the symmetries between the extra-D branes. We describe a scotogenic $A_4$ orbifold predicting the ``golden'' quark-lepton mass relation, large neutrino mass with normal ordering, higher atmospheric octant, restricted reactor angle, and an excellent global flavour fit, including quark observables. Finally, we discuss promising recent progress in tackling the flavor issue through the use of modular symmetries.
[ { "created": "Mon, 26 Feb 2024 19:01:34 GMT", "version": "v1" } ]
2024-02-28
[ [ "Ding", "Gui-Jun", "" ], [ "Valle", "Jose W. F.", "" ] ]
The Standard Model lacks an organizing principle to describe quark and lepton ``flavours''. We review the impact of neutrino oscillation experiments, which show that leptons mix very differently from quarks, placing a major challenge, but also providing a key input to the flavour puzzle. We briefly sketch the seesaw and ``scotogenic'' approaches to neutrino mass, the latter including also WIMP dark matter. We discuss the limitations of popular neutrino mixing patterns and examine the possibility that they arise from symmetry, giving a bottom-up approach to residual flavour and CP symmetries. We show how family and/or CP symmetries can generate novel viable and predictive mixing patterns. We review the model-independent ways to predict lepton mixing and test both mixing predictions as well as mass sum rules. We also discuss UV-complete flavour theories in four and more space-time dimensions, and their predictions. Benchmarks given include an $A_4$ scotogenic construction with trimaximal mixing pattern TM2. Higher-dimensional completions are also reviewed, such as 5-D warped flavordynamics. We present a $T^\prime$ warped flavordynamics theory with TM1 mixing pattern, detectable neutrinoless double beta decay rates and providing a very good fit of flavour observables, including quarks. We also review how 6-D orbifolds offer a way to determine the structure of the 4-D family symmetry from the symmetries between the extra-D branes. We describe a scotogenic $A_4$ orbifold predicting the ``golden'' quark-lepton mass relation, large neutrino mass with normal ordering, higher atmospheric octant, restricted reactor angle, and an excellent global flavour fit, including quark observables. Finally, we discuss promising recent progress in tackling the flavor issue through the use of modular symmetries.
2303.16273
Ivan Aleksandrov
I. A. Aleksandrov, V. M. Shabaev
Vacuum birefringence and dichroism in a strong plane-wave background
11 pages, 6 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the present study, we consider the effects of vacuum birefringence and dichroism in strong electromagnetic fields. According to quantum electrodynamics, the vacuum state exhibits different refractive properties depending on the probe photon polarization and one also obtains different probabilities of the photon decay via production of electron-positron pairs. Here we investigate these two phenomena by means of several different approaches to computing the polarization operator. The external field is assumed to be a linearly polarized plane electromagnetic wave of arbitrary amplitude and frequency. Varying the probe-photon energy and the field parameters, we thoroughly examine the validity of the locally-constant field approximation (LCFA) and techniques involving perturbative expansions in terms of the external-field amplitude. Within the latter approach, we develop a numerical method based on a direct evaluation of the weak-field Feynman diagrams, which can be employed for investigating more complex external backgrounds. It is demonstrated that the polarization operator depends on two parameters: classical nonlinearity parameter $\xi$ and the product $\eta = \omega q_0 / m^2$ of the laser field frequency $\omega$ and the photon energy $q_0$ ($m$ is the electron mass). The domains of validity of the approximate techniques in the $\xi \eta$ plane are explicitly identified.
[ { "created": "Tue, 28 Mar 2023 19:31:13 GMT", "version": "v1" } ]
2023-03-30
[ [ "Aleksandrov", "I. A.", "" ], [ "Shabaev", "V. M.", "" ] ]
In the present study, we consider the effects of vacuum birefringence and dichroism in strong electromagnetic fields. According to quantum electrodynamics, the vacuum state exhibits different refractive properties depending on the probe photon polarization and one also obtains different probabilities of the photon decay via production of electron-positron pairs. Here we investigate these two phenomena by means of several different approaches to computing the polarization operator. The external field is assumed to be a linearly polarized plane electromagnetic wave of arbitrary amplitude and frequency. Varying the probe-photon energy and the field parameters, we thoroughly examine the validity of the locally-constant field approximation (LCFA) and techniques involving perturbative expansions in terms of the external-field amplitude. Within the latter approach, we develop a numerical method based on a direct evaluation of the weak-field Feynman diagrams, which can be employed for investigating more complex external backgrounds. It is demonstrated that the polarization operator depends on two parameters: classical nonlinearity parameter $\xi$ and the product $\eta = \omega q_0 / m^2$ of the laser field frequency $\omega$ and the photon energy $q_0$ ($m$ is the electron mass). The domains of validity of the approximate techniques in the $\xi \eta$ plane are explicitly identified.
0806.4374
Jorge Noronha
Jorge Noronha and Miklos Gyulassy
Mach-like Angular Correlations Arise Only From the Head Zone of AdS/CFT String Jets
6 pages, 1 figure, Proceedings of the 24th Winter Workshop on Nuclear Dynamics, South Padre Island (TX, USA), April 05-12, 2008
null
null
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that Mach-like azimuthal correlations of associated hadrons in the wake of heavy quark jets modeled in the AdS/CFT string drag picture originate only from the near-quark ``Head'' region. The contributions from the far zones lead only to a yield peaked in the opposite direction with respect to the trigger jet.
[ { "created": "Thu, 26 Jun 2008 19:02:48 GMT", "version": "v1" } ]
2008-06-28
[ [ "Noronha", "Jorge", "" ], [ "Gyulassy", "Miklos", "" ] ]
We show that Mach-like azimuthal correlations of associated hadrons in the wake of heavy quark jets modeled in the AdS/CFT string drag picture originate only from the near-quark ``Head'' region. The contributions from the far zones lead only to a yield peaked in the opposite direction with respect to the trigger jet.
1902.06774
Yohei Kawakami
Yohei Kawakami and Masayasu Harada
Single heavy baryons with chiral partner structure in a three-flavor chiral model
13 pages, 1 figure. arXiv admin note: text overlap with arXiv:1804.04872
Phys. Rev. D 99, 094016 (2019)
10.1103/PhysRevD.99.094016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct an effective hadronic model including single heavy baryons (SHBs) belonging to the $(\mathbf{3},\mathbf{3})$ representation under $\mbox{SU}(3)_L \times \mbox{SU}(3)_R$ symmetry, respecting the chiral symmetry and heavy-qaurk spin-flavor symmetry. When the chiral symmetry is spontaneously broken, the SHBs are divided into the baryons with negative parity of $\bar{\mathbf 3}$ representation under $\mbox{SU}(3)$ flavor symmetry which is the chiral partners to the ones with positive parity of ${\mathbf 6}$ representation. We determine the model parameters from the available experimental data for the masses and strong decay widths of $\Sigma_c^{(\ast)}$, $\Lambda_c (2595)$, $\Xi_c (2790)$, and $\Xi_c (2815)$. Then, we predict the masses and strong decay widths of other baryons including $\Xi_b$ with negative parity. We also study radiative decays of SHBs including $\Omega_c^\ast$ and $\Omega_b^\ast$ with positive parity.
[ { "created": "Mon, 18 Feb 2019 19:47:42 GMT", "version": "v1" }, { "created": "Mon, 25 Feb 2019 08:09:02 GMT", "version": "v2" }, { "created": "Fri, 5 Apr 2019 14:30:10 GMT", "version": "v3" } ]
2019-05-22
[ [ "Kawakami", "Yohei", "" ], [ "Harada", "Masayasu", "" ] ]
We construct an effective hadronic model including single heavy baryons (SHBs) belonging to the $(\mathbf{3},\mathbf{3})$ representation under $\mbox{SU}(3)_L \times \mbox{SU}(3)_R$ symmetry, respecting the chiral symmetry and heavy-qaurk spin-flavor symmetry. When the chiral symmetry is spontaneously broken, the SHBs are divided into the baryons with negative parity of $\bar{\mathbf 3}$ representation under $\mbox{SU}(3)$ flavor symmetry which is the chiral partners to the ones with positive parity of ${\mathbf 6}$ representation. We determine the model parameters from the available experimental data for the masses and strong decay widths of $\Sigma_c^{(\ast)}$, $\Lambda_c (2595)$, $\Xi_c (2790)$, and $\Xi_c (2815)$. Then, we predict the masses and strong decay widths of other baryons including $\Xi_b$ with negative parity. We also study radiative decays of SHBs including $\Omega_c^\ast$ and $\Omega_b^\ast$ with positive parity.
1909.02951
Eric Moffat
E. Moffat, T. C. Rogers, N. Sato, and A. Signori
Collinear Factorization in Wide-Angle Hadron Pair Production in $e^+e^-$ Annihilation
16 pages, 5 figures
Phys. Rev. D 100, 094014 (2019)
10.1103/PhysRevD.100.094014
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the inclusive unpolarized dihadron production cross section in the far from back-to-back region of $e^+ e^-$ annihilation in leading order pQCD using existing fragmentation function fits and standard collinear factorization, focusing on the large transverse momentum region where transverse momentum is comparable to the hard scale (the center-of-mass energy). We compare with standard transverse-momentum-dependent (TMD) fragmentation function-based predictions intended for the small transverse momentum region with the aim of testing the expectation that the two types of calculation roughly coincide at intermediate transverse momentum. We find significant tension, within the intermediate transverse momentum region, between calculations done with existing non-perturbative TMD fragmentation functions and collinear factorization calculations if the center-of-mass energy is not extremely large. We argue that $e^+ e^-$ measurements are ideal for resolving this tension and exploring the large-to-small transverse momentum transition, given the typically larger hard scales ($\gtrsim 10$ GeV) of the process as compared with similar scenarios that arise in semi-inclusive deep inelastic scattering and fixed-target Drell-Yan measurements.
[ { "created": "Fri, 6 Sep 2019 14:59:36 GMT", "version": "v1" }, { "created": "Mon, 9 Sep 2019 20:26:27 GMT", "version": "v2" } ]
2019-11-20
[ [ "Moffat", "E.", "" ], [ "Rogers", "T. C.", "" ], [ "Sato", "N.", "" ], [ "Signori", "A.", "" ] ]
We compute the inclusive unpolarized dihadron production cross section in the far from back-to-back region of $e^+ e^-$ annihilation in leading order pQCD using existing fragmentation function fits and standard collinear factorization, focusing on the large transverse momentum region where transverse momentum is comparable to the hard scale (the center-of-mass energy). We compare with standard transverse-momentum-dependent (TMD) fragmentation function-based predictions intended for the small transverse momentum region with the aim of testing the expectation that the two types of calculation roughly coincide at intermediate transverse momentum. We find significant tension, within the intermediate transverse momentum region, between calculations done with existing non-perturbative TMD fragmentation functions and collinear factorization calculations if the center-of-mass energy is not extremely large. We argue that $e^+ e^-$ measurements are ideal for resolving this tension and exploring the large-to-small transverse momentum transition, given the typically larger hard scales ($\gtrsim 10$ GeV) of the process as compared with similar scenarios that arise in semi-inclusive deep inelastic scattering and fixed-target Drell-Yan measurements.
0809.3794
Kirill Tuchin
Dmitri Kharzeev, Eugene Levin, Kirill Tuchin
Broken scale invariance, massless dilaton and confinement in QCD
18 pages, 2 figures; v2: fixed numerous typos
null
10.1088/1126-6708/2009/06/055
RBRC-757, TAUP-2882-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Classical conformal invariance of QCD in the chiral limit is broken explicitly by scale anomaly. As a result, the lightest scalar particle (scalar glueball, or dilaton) in QCD is not light, and cannot be described as a Goldstone boson. Nevertheless basing on an effective low-energy theory of broken scale invariance we argue that inside the hadrons the non-perturbative interactions of gluon fields result in the emergence of a massless dilaton excitation (which we call the "scalaron"). We demonstrate that our effective theory of broken scale invariance leads to confinement. This theory allows a dual formulation as a classical Yang-Mills theory on a curved conformal space-time background. Possible applications are discussed, including the description of strongly coupled quark-gluon plasma and the spin structure of hadrons.
[ { "created": "Mon, 22 Sep 2008 20:18:07 GMT", "version": "v1" }, { "created": "Wed, 18 Feb 2009 18:54:31 GMT", "version": "v2" } ]
2015-05-13
[ [ "Kharzeev", "Dmitri", "" ], [ "Levin", "Eugene", "" ], [ "Tuchin", "Kirill", "" ] ]
Classical conformal invariance of QCD in the chiral limit is broken explicitly by scale anomaly. As a result, the lightest scalar particle (scalar glueball, or dilaton) in QCD is not light, and cannot be described as a Goldstone boson. Nevertheless basing on an effective low-energy theory of broken scale invariance we argue that inside the hadrons the non-perturbative interactions of gluon fields result in the emergence of a massless dilaton excitation (which we call the "scalaron"). We demonstrate that our effective theory of broken scale invariance leads to confinement. This theory allows a dual formulation as a classical Yang-Mills theory on a curved conformal space-time background. Possible applications are discussed, including the description of strongly coupled quark-gluon plasma and the spin structure of hadrons.
1605.01937
Luis Anchordoqui
Luis A. Anchordoqui, Haim Goldberg, and Xing Huang
Constraints on 750 GeV colorless Q-onia from running couplings
This version includes effects of longitudinal modes decays in HZ
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present yet another composite model explaining the relatively broad peak in the diphoton invariant mass distribution around 750 GeV recently observed at the LHC experiments. We consider the excess originates in bound states of vector-like fermions Q transforming under the electroweak group (but not QCD) of the standard model and which are also charged under a new SU(N_{TC}) QCD-like confining force. Since the new uncolored fields transform as SU(2) doublets they can acquire a mass through Yukawa interactions with the electroweak Higgs doublet, as quarks and leptons. We parametrize the Q-onium bound state using the Coulomb approximation and give a numerical fit to the diphoton excess consistent with no strong coupling effects up to about 30 TeV, which is the energy scale for next generation colliders. The range of allowed hypercharge Y_Q is given by 2.26 \leq Y_Q \leq 2.53 for N_{\rm TC} =2 and 2.17 \leq Y_Q \leq 2.31 for N_{\rm TC} = 3. The smoking gun for the model would be the discovery of Q-onia decaying into Higgs and Z-boson.
[ { "created": "Fri, 6 May 2016 13:44:29 GMT", "version": "v1" }, { "created": "Fri, 13 May 2016 17:23:30 GMT", "version": "v2" } ]
2016-05-16
[ [ "Anchordoqui", "Luis A.", "" ], [ "Goldberg", "Haim", "" ], [ "Huang", "Xing", "" ] ]
We present yet another composite model explaining the relatively broad peak in the diphoton invariant mass distribution around 750 GeV recently observed at the LHC experiments. We consider the excess originates in bound states of vector-like fermions Q transforming under the electroweak group (but not QCD) of the standard model and which are also charged under a new SU(N_{TC}) QCD-like confining force. Since the new uncolored fields transform as SU(2) doublets they can acquire a mass through Yukawa interactions with the electroweak Higgs doublet, as quarks and leptons. We parametrize the Q-onium bound state using the Coulomb approximation and give a numerical fit to the diphoton excess consistent with no strong coupling effects up to about 30 TeV, which is the energy scale for next generation colliders. The range of allowed hypercharge Y_Q is given by 2.26 \leq Y_Q \leq 2.53 for N_{\rm TC} =2 and 2.17 \leq Y_Q \leq 2.31 for N_{\rm TC} = 3. The smoking gun for the model would be the discovery of Q-onia decaying into Higgs and Z-boson.
1512.07961
Daijiro Suematsu
Shoichi Kashiwase and Daijiro Suematsu
Radiative neutrino mass model with degenerate right-handed neutrinos
28 pages, 3 figures, accepted version for publication
null
10.1140/epjc/s10052-016-3964-5
KANAZAWA-15-16
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The radiative neutrino mass model can relate neutrino masses and dark matter at a TeV scale. If we apply this model to thermal leptogenesis, we need to consider resonant leptogenesis at that scale. It requires both finely degenerate masses for the right-handed neutrinos and a tiny neutrino Yukawa coupling. We propose an extension of the model with a U(1) gauge symmetry, in which these conditions are shown to be simultaneously realized through a TeV scale symmetry breaking. Moreover, this extension can bring about a small quartic scalar coupling between the Higgs doublet scalar and an inert doublet scalar which characterizes the radiative neutrino mass generation. It also is the origin of the $Z_2$ symmetry which guarantees the stability of dark matter. Several assumptions which are independently supposed in the original model are closely connected through this extension.
[ { "created": "Fri, 25 Dec 2015 05:37:20 GMT", "version": "v1" }, { "created": "Wed, 2 Mar 2016 06:35:00 GMT", "version": "v2" } ]
2016-03-23
[ [ "Kashiwase", "Shoichi", "" ], [ "Suematsu", "Daijiro", "" ] ]
The radiative neutrino mass model can relate neutrino masses and dark matter at a TeV scale. If we apply this model to thermal leptogenesis, we need to consider resonant leptogenesis at that scale. It requires both finely degenerate masses for the right-handed neutrinos and a tiny neutrino Yukawa coupling. We propose an extension of the model with a U(1) gauge symmetry, in which these conditions are shown to be simultaneously realized through a TeV scale symmetry breaking. Moreover, this extension can bring about a small quartic scalar coupling between the Higgs doublet scalar and an inert doublet scalar which characterizes the radiative neutrino mass generation. It also is the origin of the $Z_2$ symmetry which guarantees the stability of dark matter. Several assumptions which are independently supposed in the original model are closely connected through this extension.
hep-ph/0005062
Ina Sarcevic
Ina Sarcevic (University of Arizona)
Parton Distributions in Nuclei at Small x
Invited talk presented at the XXIX International Symposium on Multiparticle Dynamics, QCD and Multiparticle Dynamics, Providence, RI, August 9-13, 1999; 6 pages, PostScript, 4 color figures
null
null
null
hep-ph
null
We study the nuclear shadowing effect in the context of Glauber-Gribov multiple-scattering model and perturbative QCD. We find that at small x, the $Q^2$ evolution of the shadowing is much slower than the DGLAP evolution, due to the multiple scatterings at small x. We show that the gluon shadowing at small x and for $Q^2 > 3GeV^2$ is perturbative in nature and does not depend on the initial, non-perturbative condition. We evaluate the impact parameter dependence of the gluon distribution and show that it is a non-linear effect in the nuclear thickness function.
[ { "created": "Mon, 8 May 2000 03:25:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sarcevic", "Ina", "", "University of Arizona" ] ]
We study the nuclear shadowing effect in the context of Glauber-Gribov multiple-scattering model and perturbative QCD. We find that at small x, the $Q^2$ evolution of the shadowing is much slower than the DGLAP evolution, due to the multiple scatterings at small x. We show that the gluon shadowing at small x and for $Q^2 > 3GeV^2$ is perturbative in nature and does not depend on the initial, non-perturbative condition. We evaluate the impact parameter dependence of the gluon distribution and show that it is a non-linear effect in the nuclear thickness function.
1205.3849
Zhen-hua Zhao
Chun Liu, Zhen-hua Zhao
$\theta_{13}$ and the Higgs mass from high scale supersymmetry
13 pages, no figure, revtex4, revised version
Commun. Theor. Phys. 59 (2013) 467-471
10.1088/0253-6102/59/4/14
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework in which supersymmetry is used for understanding fermion masses rather than stabilizing the electroweak scale, we elaborate the phenomenological analysis for the neutrino physics. A relatively large $\sin{\theta_{13}}$ is the natural result. The model further predicts vanishingly small CP violation in neutrino oscillations. And $\theta_{23}$ is not necessarily maximal. While the high scale supersymmetry generically results in a Higgs mass of about 141 GeV, our model reduces this mass via introducing SU(2)$_L$ triplet fields which also contribute to neutrino masses.
[ { "created": "Thu, 17 May 2012 05:00:15 GMT", "version": "v1" }, { "created": "Tue, 19 Feb 2013 01:05:45 GMT", "version": "v2" } ]
2015-06-05
[ [ "Liu", "Chun", "" ], [ "Zhao", "Zhen-hua", "" ] ]
In the framework in which supersymmetry is used for understanding fermion masses rather than stabilizing the electroweak scale, we elaborate the phenomenological analysis for the neutrino physics. A relatively large $\sin{\theta_{13}}$ is the natural result. The model further predicts vanishingly small CP violation in neutrino oscillations. And $\theta_{23}$ is not necessarily maximal. While the high scale supersymmetry generically results in a Higgs mass of about 141 GeV, our model reduces this mass via introducing SU(2)$_L$ triplet fields which also contribute to neutrino masses.
0803.1223
Zhi-Gang Wang
Zhi-Gang Wang
Radiative decays of the $(0^+,1^+)$ strange-bottom mesons
16 pages, 4 figures, revised version
Commun.Theor.Phys.52:91-98,2009
10.1088/0253-6102/52/1/21
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we assume that the $(0^+,1^+)$ strange-bottom mesons are the conventional $b\bar{s}$ mesons, and calculate the electromagnetic coupling constants $d$, $g_1$, $g_2$ and $g_3$ using the light-cone QCD sum rules. Then we study the radiative decays $B_{s0}\to B_s^* \gamma$, $B_{s1}\to B_s \gamma$, $B_{s1}\to B_s^* \gamma$ and $B_{s1}\to B_{s0} \gamma$, and observe that the widths are rather narrow. We can search for the $(0^+,1^+)$ strange-bottom mesons in the invariant $B_s \pi^0$ and $B^*_s \pi^0$ mass distributions in the strong decays or in the invariant $B_s^*\gamma$ and $B_s\gamma$ mass distributions in the radiative decays.
[ { "created": "Sat, 8 Mar 2008 07:36:55 GMT", "version": "v1" }, { "created": "Sat, 17 May 2008 13:44:35 GMT", "version": "v2" }, { "created": "Mon, 9 Mar 2009 09:10:22 GMT", "version": "v3" } ]
2009-08-18
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we assume that the $(0^+,1^+)$ strange-bottom mesons are the conventional $b\bar{s}$ mesons, and calculate the electromagnetic coupling constants $d$, $g_1$, $g_2$ and $g_3$ using the light-cone QCD sum rules. Then we study the radiative decays $B_{s0}\to B_s^* \gamma$, $B_{s1}\to B_s \gamma$, $B_{s1}\to B_s^* \gamma$ and $B_{s1}\to B_{s0} \gamma$, and observe that the widths are rather narrow. We can search for the $(0^+,1^+)$ strange-bottom mesons in the invariant $B_s \pi^0$ and $B^*_s \pi^0$ mass distributions in the strong decays or in the invariant $B_s^*\gamma$ and $B_s\gamma$ mass distributions in the radiative decays.
hep-ph/0608117
Fran\c{c}ois Gelis
Francois Gelis, Raju Venugopalan
Particle production and AGK relations in the Color Glass Condensate picture
10 pages, based on talks given at the XLIst Rencontres de Moriond (March 2006, La Thuile, Italy), at SEWM'06 (May 2006, BNL, USA), at the 5th International Conference on Perspectives in Hadronic Physics (May 2006, Trieste, Italy), and at Hard Probes 2006 (June 2006, Asilomar, USA)
Nucl.Phys.A782:297-304,2007; Nucl.Phys.A785:146-149,2007
10.1016/j.nuclphysa.2006.10.062 10.1016/j.nuclphysa.2006.11.152
null
hep-ph nucl-ex nucl-th
null
In this talk, we discuss some general properties of particle production in a field theory coupled to strong time dependent sources, and techniques to compute the spectrum of the produced particles in such theories. We also discuss the application of these results to the description of hadron or heavy ion collisions in the Color Glass Condensate framework.
[ { "created": "Thu, 10 Aug 2006 15:31:32 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gelis", "Francois", "" ], [ "Venugopalan", "Raju", "" ] ]
In this talk, we discuss some general properties of particle production in a field theory coupled to strong time dependent sources, and techniques to compute the spectrum of the produced particles in such theories. We also discuss the application of these results to the description of hadron or heavy ion collisions in the Color Glass Condensate framework.
2402.05465
Jian Zhou Mr.
Ding Yu Shao, Yu Shi, Cheng Zhang, Jian Zhou, Ya-jin Zhou
Revisiting azimuthal angular asymmetries in diffractive di-jet production
20 pages, 5 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We explore the impact of initial state soft gluon radiations on the azimuthal angle asymmetries in photo-production of hard di-jet via coherent diffraction in ultraperipheral heavy ion collisions, as well as in electron-proton ($ep$) and electron-nucleus ($eA$) collisions. The primary production mechanism is identified as the diffractive production of two hard jets, accompanied by a collinear gluon emission along the beam direction. In contrast, the diffractive exclusive di-jet production, where the initial state radiation is absent, is suppressed due to color transparency. Our analysis shows that azimuthal asymmetries, traditionally attributed to final state gluon emissions, are reduced by the presence of initial state radiations. The sensitivity of azimuthal asymmetries to both initial and final state radiations suggests that they could provide novel insights into the mechanisms of di-jet production in diffractive processes.
[ { "created": "Thu, 8 Feb 2024 07:55:10 GMT", "version": "v1" } ]
2024-02-09
[ [ "Shao", "Ding Yu", "" ], [ "Shi", "Yu", "" ], [ "Zhang", "Cheng", "" ], [ "Zhou", "Jian", "" ], [ "Zhou", "Ya-jin", "" ] ]
We explore the impact of initial state soft gluon radiations on the azimuthal angle asymmetries in photo-production of hard di-jet via coherent diffraction in ultraperipheral heavy ion collisions, as well as in electron-proton ($ep$) and electron-nucleus ($eA$) collisions. The primary production mechanism is identified as the diffractive production of two hard jets, accompanied by a collinear gluon emission along the beam direction. In contrast, the diffractive exclusive di-jet production, where the initial state radiation is absent, is suppressed due to color transparency. Our analysis shows that azimuthal asymmetries, traditionally attributed to final state gluon emissions, are reduced by the presence of initial state radiations. The sensitivity of azimuthal asymmetries to both initial and final state radiations suggests that they could provide novel insights into the mechanisms of di-jet production in diffractive processes.
1803.08528
Diego Restrepo
M. Reig, D. Restrepo, J. W. F. Valle and O. Zapata
Bound-state dark matter and Dirac neutrino mass
7 pages, 3 figures
Phys. Rev. D 97, 115032 (2018)
10.1103/PhysRevD.97.115032
IFIC/18-XXX
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose a simple theory for the idea that cosmological dark matter (DM) may be present today mainly in the form of stable neutral hadronic thermal relics. In our model neutrino masses arise radiatively from the exchange of colored DM constituents, giving a common origin for both dark matter and neutrino mass. The exact conservation of $B-L$ symmetry ensures dark matter stability and the Dirac nature of neutrinos. The theory can be falsified by dark matter nuclear recoil direct detection experiments, leading also to possible signals at a next generation hadron collider.
[ { "created": "Thu, 22 Mar 2018 18:11:54 GMT", "version": "v1" } ]
2018-06-27
[ [ "Reig", "M.", "" ], [ "Restrepo", "D.", "" ], [ "Valle", "J. W. F.", "" ], [ "Zapata", "O.", "" ] ]
We propose a simple theory for the idea that cosmological dark matter (DM) may be present today mainly in the form of stable neutral hadronic thermal relics. In our model neutrino masses arise radiatively from the exchange of colored DM constituents, giving a common origin for both dark matter and neutrino mass. The exact conservation of $B-L$ symmetry ensures dark matter stability and the Dirac nature of neutrinos. The theory can be falsified by dark matter nuclear recoil direct detection experiments, leading also to possible signals at a next generation hadron collider.
hep-ph/9812273
Ed Stoeffhaas
V. Barger and K. Whisnant
Global Three-Neutrino Vacuum Oscillation fits to the Solar and Atmospheric Anomalies
Revtex, 31 pages, uses epsf.sty, 14 postscript figures. Version to be published in Phys. Rev. D
Phys.Rev.D59:093007,1999
10.1103/PhysRevD.59.093007
MADPH-98-1080, FERMILAB-Pub-98/385-T, AMES-HET-98-13
hep-ph astro-ph
null
We determine the three-neutrino mixing and mass parameters that are allowed by the solar and atmospheric neutrino data when vacuum oscillations are responsible for both phenomena. The global fit does not appreciably change the allowed regions for the parameters obtained from effective two-neutrino fits. We discuss how measurements of the solar electron energy spectrum below 6.5 GeV in Super-Kamiokande and seasonal variations in the Super-Kamiokande, $^{71}$Ga, and BOREXINO experiments can distinguish the different solar vacuum solutions.
[ { "created": "Mon, 7 Dec 1998 22:14:11 GMT", "version": "v1" }, { "created": "Wed, 16 Dec 1998 20:34:32 GMT", "version": "v2" }, { "created": "Wed, 24 Feb 1999 19:43:38 GMT", "version": "v3" } ]
2009-08-07
[ [ "Barger", "V.", "" ], [ "Whisnant", "K.", "" ] ]
We determine the three-neutrino mixing and mass parameters that are allowed by the solar and atmospheric neutrino data when vacuum oscillations are responsible for both phenomena. The global fit does not appreciably change the allowed regions for the parameters obtained from effective two-neutrino fits. We discuss how measurements of the solar electron energy spectrum below 6.5 GeV in Super-Kamiokande and seasonal variations in the Super-Kamiokande, $^{71}$Ga, and BOREXINO experiments can distinguish the different solar vacuum solutions.
hep-ph/0210148
Alfredo Takashi Suzuki
A.T.Suzuki, E.S.Santos, and A.G.M.Schmidt
General massive one-loop off-shell three-point functions
16 pages, 2 figures, 4 tables
J.Phys.A36:4465,2003
10.1088/0305-4470/36/15/317
null
hep-ph
null
In this work we compute the most general massive one-loop off-shell three-point vertex in D-dimensions, where the masses, external momenta, and exponents of propagators are arbitrary. This follows our previous paper in which we have calculated several new hypergeometric series representations for massless and massive (with equal masses) scalar one-loop three-point functions, in the negative dimensional approach.
[ { "created": "Wed, 9 Oct 2002 18:28:23 GMT", "version": "v1" } ]
2008-11-26
[ [ "Suzuki", "A. T.", "" ], [ "Santos", "E. S.", "" ], [ "Schmidt", "A. G. M.", "" ] ]
In this work we compute the most general massive one-loop off-shell three-point vertex in D-dimensions, where the masses, external momenta, and exponents of propagators are arbitrary. This follows our previous paper in which we have calculated several new hypergeometric series representations for massless and massive (with equal masses) scalar one-loop three-point functions, in the negative dimensional approach.
0906.4911
Leszek Roszkowski
Daniel E. Lopez-Fogliani, Leszek Roszkowski, Roberto Ruiz de Austri and Tom A. Varley
A Bayesian Analysis of the Constrained NMSSM
null
null
10.1103/PhysRevD.80.095013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a first global exploration of the Constrained Next-to-Minimal Supersymmetric Standard Model using Bayesian statistics. We derive several global features of the model and find that, in some contrast to initial expectations, they closely resemble the Constrained MSSM. This remains true even away from the decoupling limit which is nevertheless strongly preferred. We present ensuing implications for several key observables, including collider signatures and predictions for direct detection of dark matter.
[ { "created": "Fri, 26 Jun 2009 19:47:17 GMT", "version": "v1" } ]
2015-05-13
[ [ "Lopez-Fogliani", "Daniel E.", "" ], [ "Roszkowski", "Leszek", "" ], [ "de Austri", "Roberto Ruiz", "" ], [ "Varley", "Tom A.", "" ] ]
We perform a first global exploration of the Constrained Next-to-Minimal Supersymmetric Standard Model using Bayesian statistics. We derive several global features of the model and find that, in some contrast to initial expectations, they closely resemble the Constrained MSSM. This remains true even away from the decoupling limit which is nevertheless strongly preferred. We present ensuing implications for several key observables, including collider signatures and predictions for direct detection of dark matter.
1012.2571
Wayne W. Repko
Duane A. Dicus, Shao-Feng Ge and Wayne W. Repko
Generalized Hidden $\mathcal{Z}_2$ Symmetry of Neutrino Mixing
10 pages, 1 table, 5 figures, revised references
Phys.Rev.D83:093007,2011
10.1103/PhysRevD.83.093007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the consequences of the neutrino mass matrix having a hidden $\mathcal{Z}_2$ symmetry and one zero eigenvalue. When implemented, these two conditions give relations among the mixing angles. In addition, fitting these relations to the existing oscillation data allows limits to be placed on the parameter of the symmetry.
[ { "created": "Sun, 12 Dec 2010 18:34:50 GMT", "version": "v1" }, { "created": "Fri, 7 Jan 2011 16:18:56 GMT", "version": "v2" }, { "created": "Sun, 27 Feb 2011 17:06:32 GMT", "version": "v3" } ]
2015-03-17
[ [ "Dicus", "Duane A.", "" ], [ "Ge", "Shao-Feng", "" ], [ "Repko", "Wayne W.", "" ] ]
We explore the consequences of the neutrino mass matrix having a hidden $\mathcal{Z}_2$ symmetry and one zero eigenvalue. When implemented, these two conditions give relations among the mixing angles. In addition, fitting these relations to the existing oscillation data allows limits to be placed on the parameter of the symmetry.
0905.4925
Hael Collins
Hael Collins (Niels Bohr International Academy) and R. Holman (Carnegie Mellon University)
Trans-Planckian enhancements of the primordial non-Gaussianities
12 pages, 1 figure, uses ReVTeX
Phys.Rev.D80:043524,2009
10.1103/PhysRevD.80.043524
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article examines how breaking a Lorentz-invariant description of nature at tiny space-time intervals would affect the non-Gaussian character of the pattern of primordial perturbations left by inflation. We specifically study a set of irrelevant operators that preserve the spatial symmetries of the usual inflationary background. The non-Gaussian component in the primordial fluctuations can be much larger than the usual, small, inflationary prediction and can thus lead to much stronger constraints on the role of "trans-Planckian" physics in inflation than those from the measurements of the primordial power spectrum.
[ { "created": "Fri, 29 May 2009 17:35:25 GMT", "version": "v1" } ]
2009-09-01
[ [ "Collins", "Hael", "", "Niels Bohr International Academy" ], [ "Holman", "R.", "", "Carnegie Mellon University" ] ]
This article examines how breaking a Lorentz-invariant description of nature at tiny space-time intervals would affect the non-Gaussian character of the pattern of primordial perturbations left by inflation. We specifically study a set of irrelevant operators that preserve the spatial symmetries of the usual inflationary background. The non-Gaussian component in the primordial fluctuations can be much larger than the usual, small, inflationary prediction and can thus lead to much stronger constraints on the role of "trans-Planckian" physics in inflation than those from the measurements of the primordial power spectrum.
1208.2289
Charles Gale
Charles Gale
Electromagnetic radiation in heavy ion collisions: Progress and puzzles
Talk presented at the 5th International Conference on Hard and Electromagnetic Probes of High Energy Nuclear Collisions (Hard Probes 2012), May 27 - June 1, 2012, Cagliari, Italy
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the current state of photon and dilepton measurements at RHIC, emphasizing that of the theoretical work seeking to interpret them. We highlight the progress made recently in the modelling of relativistic nuclear collisions, and explore the effect on electromagnetic observables. Some outstanding puzzles are presented.
[ { "created": "Fri, 10 Aug 2012 21:12:40 GMT", "version": "v1" }, { "created": "Fri, 14 Sep 2012 14:05:35 GMT", "version": "v2" }, { "created": "Wed, 24 Oct 2012 19:26:11 GMT", "version": "v3" } ]
2012-10-25
[ [ "Gale", "Charles", "" ] ]
We review the current state of photon and dilepton measurements at RHIC, emphasizing that of the theoretical work seeking to interpret them. We highlight the progress made recently in the modelling of relativistic nuclear collisions, and explore the effect on electromagnetic observables. Some outstanding puzzles are presented.
1205.5789
Piyush Kumar
Bobby Samir Acharya, Gordon Kane, Piyush Kumar, Ran Lu, Bob Zheng
Mixed Wino-Axion Dark Matter in String/M Theory and the 130 GeV Gamma-line "Signal"
9 pages, 5 Figures
null
null
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
String/M theory compactifications with low energy supersymmetry tend to predict that dark matter has two components: axions and WIMPs \cite{1004.5138,1204.2795}. In accord with this, we show that the tentative 130 GeV gamma-line signal reported in \cite{1204.2797} can be interpreted as arising from the annihilation of 145 GeV mass, Wino-like WIMPs into a Z-boson and a photon. In this context, the signal implies a second component of dark matter which we interpret as being composed of axions - the relative Wino/Axion abundances being approximately equal. Further predictions are implied: signals in both diffuse and monochromatic photons from dwarf spheroidal galaxies; monochromatic photons with energy 145 GeV; for the LHC, the Higgs boson mass has been predicted in this framework \cite{1112.1059}, and the current Higgs limits provide interesting constraints on the mass of the Gluino.
[ { "created": "Fri, 25 May 2012 19:48:26 GMT", "version": "v1" } ]
2012-05-28
[ [ "Acharya", "Bobby Samir", "" ], [ "Kane", "Gordon", "" ], [ "Kumar", "Piyush", "" ], [ "Lu", "Ran", "" ], [ "Zheng", "Bob", "" ] ]
String/M theory compactifications with low energy supersymmetry tend to predict that dark matter has two components: axions and WIMPs \cite{1004.5138,1204.2795}. In accord with this, we show that the tentative 130 GeV gamma-line signal reported in \cite{1204.2797} can be interpreted as arising from the annihilation of 145 GeV mass, Wino-like WIMPs into a Z-boson and a photon. In this context, the signal implies a second component of dark matter which we interpret as being composed of axions - the relative Wino/Axion abundances being approximately equal. Further predictions are implied: signals in both diffuse and monochromatic photons from dwarf spheroidal galaxies; monochromatic photons with energy 145 GeV; for the LHC, the Higgs boson mass has been predicted in this framework \cite{1112.1059}, and the current Higgs limits provide interesting constraints on the mass of the Gluino.
0705.3493
Kochelev Nikolai Innokentevich
Dong-Pil Min and Nikolai Kochelev
Glueball-Induced Partonic Energy Loss in Quark-Gluon Plasma
5 pages, 3 figures, version to appear in Phys.Rev.C
Phys.Rev.C77:014901,2008
10.1103/PhysRevC.77.014901
null
hep-ph
null
We discuss the energy loss of energetic parton jets in quark-gluon plasma above the deconfinement temperature $T_c$ by the interaction with scalar and pseudoscalar glueballs. It is shown that the loss by this mechanism is quite important and may play the important role of the observed jet-quenching.
[ { "created": "Thu, 24 May 2007 02:04:42 GMT", "version": "v1" }, { "created": "Fri, 8 Jun 2007 12:43:56 GMT", "version": "v2" }, { "created": "Fri, 20 Jul 2007 13:25:47 GMT", "version": "v3" }, { "created": "Tue, 18 Dec 2007 13:28:39 GMT", "version": "v4" } ]
2008-11-26
[ [ "Min", "Dong-Pil", "" ], [ "Kochelev", "Nikolai", "" ] ]
We discuss the energy loss of energetic parton jets in quark-gluon plasma above the deconfinement temperature $T_c$ by the interaction with scalar and pseudoscalar glueballs. It is shown that the loss by this mechanism is quite important and may play the important role of the observed jet-quenching.
2203.04622
Mikhail Mikhasenko
Mikhail Mikhasenko
Effective-range expansion of the $T_{cc}^+$ state at the complex $D^{*+}D^0$ threshold
5 pages, 2 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Evaluation of the effective-range parameters for the $T_{cc}^+$ state in the LHCb model is examined. The finite width of $D^*$ leads to a shift of the expansion point into the complex plane to match analytical properties of the expanded amplitude. We perform an analytic continuation of the three-body scattering amplitude to the complex plane in a vicinity of the branch point and develop a robust procedure for computation of the expansion coefficients. The results yield a nearly-real scattering length, and two contributions to the the effective range which have not been accounted before.
[ { "created": "Wed, 9 Mar 2022 10:17:54 GMT", "version": "v1" } ]
2022-03-10
[ [ "Mikhasenko", "Mikhail", "" ] ]
Evaluation of the effective-range parameters for the $T_{cc}^+$ state in the LHCb model is examined. The finite width of $D^*$ leads to a shift of the expansion point into the complex plane to match analytical properties of the expanded amplitude. We perform an analytic continuation of the three-body scattering amplitude to the complex plane in a vicinity of the branch point and develop a robust procedure for computation of the expansion coefficients. The results yield a nearly-real scattering length, and two contributions to the the effective range which have not been accounted before.
1312.0257
Jonathan Da Silva
Jonathan Da Silva
Supersymmetric Dark Matter candidates in light of constraints from collider and astroparticle observables
PhD thesis defended at LAPTh (France) on july 3, 2013. 272 pages. This PhD thesis draws heavily from arXiv:1110.2414, arXiv:1203.3446, arXiv:1205.2815 and arXiv:1208.5009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model of particle physics has been strengthened by the recent discovery of the long-awaited Higgs boson. The standard cosmological model has met the challenge of the high precision observations in cosmology and astroparticle physics. However these two standard models face both several theoretical issues, such as the naturalness problem in the Higgs sector of the Standard Model, as well as observational issues, in particular the fact that an unknown kind of matter called Dark Matter accounts for the majority of the matter content in our Universe. Attempts to solve such problems have led to the development of New Physics models during the last decades. Supersymmetry is one such model which addresses the fine-tuning problem in the Higgs sector and provides viable Dark Matter candidates. Current high energy and high precision experiments give many new opportunities to probe the supersymmetric models. It is in this context that this thesis is written. Considering the Minimal Supersymmetric Standard Model (MSSM), the simplest supersymmetric extension of the Standard Model of particle physics, and its conventional Dark Matter candidate, the neutralino, it is shown that collider constraints could provide informations on the very early Universe at the inflation area. It is also demonstrated that the Indirect Detection of Dark Matter, despite several drawbacks, can be a powerful technique to probe supersymmetric Dark Matter models. Beyond the MSSM it is shown that unique characteristics of the Dark Matter candidate in the NMSSM could be probed at colliders. The study of a supersymmetric model with an extended gauge symmetry, the UMSSM, is also developed. The features of another Dark Matter candidate of this model, the Right-Handed sneutrino, are analysed. More general constraints such as those coming from low energy observables are finally considered in this model.
[ { "created": "Sun, 1 Dec 2013 18:13:51 GMT", "version": "v1" } ]
2013-12-03
[ [ "Da Silva", "Jonathan", "" ] ]
The Standard Model of particle physics has been strengthened by the recent discovery of the long-awaited Higgs boson. The standard cosmological model has met the challenge of the high precision observations in cosmology and astroparticle physics. However these two standard models face both several theoretical issues, such as the naturalness problem in the Higgs sector of the Standard Model, as well as observational issues, in particular the fact that an unknown kind of matter called Dark Matter accounts for the majority of the matter content in our Universe. Attempts to solve such problems have led to the development of New Physics models during the last decades. Supersymmetry is one such model which addresses the fine-tuning problem in the Higgs sector and provides viable Dark Matter candidates. Current high energy and high precision experiments give many new opportunities to probe the supersymmetric models. It is in this context that this thesis is written. Considering the Minimal Supersymmetric Standard Model (MSSM), the simplest supersymmetric extension of the Standard Model of particle physics, and its conventional Dark Matter candidate, the neutralino, it is shown that collider constraints could provide informations on the very early Universe at the inflation area. It is also demonstrated that the Indirect Detection of Dark Matter, despite several drawbacks, can be a powerful technique to probe supersymmetric Dark Matter models. Beyond the MSSM it is shown that unique characteristics of the Dark Matter candidate in the NMSSM could be probed at colliders. The study of a supersymmetric model with an extended gauge symmetry, the UMSSM, is also developed. The features of another Dark Matter candidate of this model, the Right-Handed sneutrino, are analysed. More general constraints such as those coming from low energy observables are finally considered in this model.
1203.0508
S. Descotes-Genon
Veronique Bernard (IPN Orsay), Sebastien Descotes-Genon (LPT, Orsay), Guillaume Toucas (LPT, Orsay)
Topological susceptibility on the lattice and the three-flavour quark condensate
6 figures, 29 pages. Extended discussion of lattice artefacts. Accepted for publication in JHEP
null
10.1007/JHEP06(2012)051
LPT-ORSAY/12-20
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reanalyse the topological susceptibility assuming the possibility of a significant paramagnetic suppression of the three-flavour quark condensate and a correlated enhancement of vacuum fluctuations of $s\bar{s}$ pairs. Using the framework of resummed ChPT, we point out that simulations performed near the physical point, with a significant mass hierarchy between u,d and s dynamical quarks, are not able to disentangle the contributions from the quark condensate and sea $s\bar{s}$-pair fluctuations, and that simulations with three light quark masses of the same order are better suited for this purpose. We perform a combined fit of recent RBC/UKQCD data on pseudoscalar masses and decay constants as well as the topological susceptibility, and we reconsider the determination of lattice spacings in our framework, working out the consequences on the parameters of the chiral Lagrangian. We obtain Sigma(3;2 GeV)^1/3=243 \pm 12 MeV for the three-flavour quark condensate in the chiral limit. We notice a significant suppression compared to the two-flavour quark condensate Sigma(2;2 GeV)/Sigma(3;2 GeV)=1.51\pm 0.11 and we confirm previous findings of a competition between leading order and next-to-leading order contributions in three-flavour chiral series.
[ { "created": "Fri, 2 Mar 2012 16:20:35 GMT", "version": "v1" }, { "created": "Wed, 6 Jun 2012 07:34:59 GMT", "version": "v2" } ]
2015-06-04
[ [ "Bernard", "Veronique", "", "IPN Orsay" ], [ "Descotes-Genon", "Sebastien", "", "LPT, Orsay" ], [ "Toucas", "Guillaume", "", "LPT, Orsay" ] ]
We reanalyse the topological susceptibility assuming the possibility of a significant paramagnetic suppression of the three-flavour quark condensate and a correlated enhancement of vacuum fluctuations of $s\bar{s}$ pairs. Using the framework of resummed ChPT, we point out that simulations performed near the physical point, with a significant mass hierarchy between u,d and s dynamical quarks, are not able to disentangle the contributions from the quark condensate and sea $s\bar{s}$-pair fluctuations, and that simulations with three light quark masses of the same order are better suited for this purpose. We perform a combined fit of recent RBC/UKQCD data on pseudoscalar masses and decay constants as well as the topological susceptibility, and we reconsider the determination of lattice spacings in our framework, working out the consequences on the parameters of the chiral Lagrangian. We obtain Sigma(3;2 GeV)^1/3=243 \pm 12 MeV for the three-flavour quark condensate in the chiral limit. We notice a significant suppression compared to the two-flavour quark condensate Sigma(2;2 GeV)/Sigma(3;2 GeV)=1.51\pm 0.11 and we confirm previous findings of a competition between leading order and next-to-leading order contributions in three-flavour chiral series.
hep-ph/9704399
Bruce Bassett
Bruce A. Bassett
The Preheating - Gravitational Wave Correspondence
10 pages, Revtex, 3 ps figures. Matched to published version
Phys. Rev. D 56, 3439 (1997)
10.1103/PhysRevD.56.3439
null
hep-ph astro-ph gr-qc
null
The gravitational wave equations form a parametric resonance system during oscillatory reheating after inflation, when cast in terms of the electric and magnetic parts of the Weyl tensor. This is in direct analogy with preheating. For chaotic inflation with a quadratic potential, this analogy is exact. The resulting amplification of the gravitational wave spectrum begins in the broad resonance regime for chaotic inflation but quickly moves towards narrow resonance. This increases the amplitude and breaks the scale invariance of the tensor spectrum generated during inflation, an effect which may be detectable. The parametric amplification is absent, however, in 1st-order phase transition models and "warm" inflationary models with continuous entropy production.
[ { "created": "Thu, 24 Apr 1997 15:41:15 GMT", "version": "v1" }, { "created": "Tue, 6 May 1997 12:18:53 GMT", "version": "v2" }, { "created": "Wed, 24 Sep 1997 16:06:20 GMT", "version": "v3" } ]
2009-10-30
[ [ "Bassett", "Bruce A.", "" ] ]
The gravitational wave equations form a parametric resonance system during oscillatory reheating after inflation, when cast in terms of the electric and magnetic parts of the Weyl tensor. This is in direct analogy with preheating. For chaotic inflation with a quadratic potential, this analogy is exact. The resulting amplification of the gravitational wave spectrum begins in the broad resonance regime for chaotic inflation but quickly moves towards narrow resonance. This increases the amplitude and breaks the scale invariance of the tensor spectrum generated during inflation, an effect which may be detectable. The parametric amplification is absent, however, in 1st-order phase transition models and "warm" inflationary models with continuous entropy production.
hep-ph/9306235
Faraggi Alon
Alon E. Faraggi and Edi Halyo
Cabibbo--Kobayashi--Maskawa Mixing in Superstring Derived Standard--like Models
WIS--93/35/APR--PH, 29 pages
Nucl.Phys.B416:63-86,1994
10.1016/0550-3213(94)90578-9
null
hep-ph
null
We examine the problem of three generation quark flavor mixing in realistic, superstring derived standard--like models, constructed in the free fermionic formulation. We study the sources of family mixing in these models and discuss the necessary conditions to obtain a realistic Cabibbo--Kobayashi--Maskawa (CKM) mixing matrix. In a specific model, we estimate the mixing angles and discuss the weak CP violating phase. We argue that the superstring standard--like models can produce a realistic CKM mixing matrix. We discuss the possible textures of quark mass matrices that may be obtained in these models.
[ { "created": "Mon, 7 Jun 1993 14:27:13 GMT", "version": "v1" } ]
2010-11-01
[ [ "Faraggi", "Alon E.", "" ], [ "Halyo", "Edi", "" ] ]
We examine the problem of three generation quark flavor mixing in realistic, superstring derived standard--like models, constructed in the free fermionic formulation. We study the sources of family mixing in these models and discuss the necessary conditions to obtain a realistic Cabibbo--Kobayashi--Maskawa (CKM) mixing matrix. In a specific model, we estimate the mixing angles and discuss the weak CP violating phase. We argue that the superstring standard--like models can produce a realistic CKM mixing matrix. We discuss the possible textures of quark mass matrices that may be obtained in these models.
2404.14075
Xiang Liu
Cheng-Xi Liu, Li-Ming Wang, Ting-Yan Li and Xiang Liu
Likelihood analysis of the newly observed $f_0(2020)$, $f_0(2330)$ and $f_0(2470)$ in $J/\psi\to \gamma\eta^\prime\eta^\prime$ as high-lying unflavored scalar mesons
9 pages and 7 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/publicdomain/zero/1.0/
Inspired by the newly observed three scalar states $f_0(2020)$, $f_0(2330)$, and $f_0(2470)$ by the BESII Collaboration in $J/\psi\to \gamma\eta^\prime\eta^\prime$, we carried out the study of spectroscopic behavior of these high-lying unflavored scalar mesonic states. In this work, using the Regge trajectory analysis and the quark pair creation model, we discussed the assignments of the $f_0(2020)$, $f_0(2330)$, and $f_0(2470)$ associated with the $f_0(2200)$ as the isoscalar high-lying scalar mesonic states and predicted the spectroscopic properties of their high-lying partners. The present study may provide valuable information for the construction of the scalar meson family.
[ { "created": "Mon, 22 Apr 2024 10:35:37 GMT", "version": "v1" } ]
2024-04-23
[ [ "Liu", "Cheng-Xi", "" ], [ "Wang", "Li-Ming", "" ], [ "Li", "Ting-Yan", "" ], [ "Liu", "Xiang", "" ] ]
Inspired by the newly observed three scalar states $f_0(2020)$, $f_0(2330)$, and $f_0(2470)$ by the BESII Collaboration in $J/\psi\to \gamma\eta^\prime\eta^\prime$, we carried out the study of spectroscopic behavior of these high-lying unflavored scalar mesonic states. In this work, using the Regge trajectory analysis and the quark pair creation model, we discussed the assignments of the $f_0(2020)$, $f_0(2330)$, and $f_0(2470)$ associated with the $f_0(2200)$ as the isoscalar high-lying scalar mesonic states and predicted the spectroscopic properties of their high-lying partners. The present study may provide valuable information for the construction of the scalar meson family.
2012.03640
Sigtryggur Hauksson
Sigtryggur Hauksson, Sangyong Jeon, Charles Gale
Probes of the quark-gluon plasma and plasma instabilities
17 pages, 12 figures
Phys. Rev. C 103, 064904 (2021)
10.1103/PhysRevC.103.064904
null
hep-ph nucl-th
http://creativecommons.org/licenses/by-nc-nd/4.0/
Penetrating probes in heavy-ion collisions, like jets and photons, are sensitive to the transport coefficients of the produced quark-gluon plasma, such as shear and bulk viscosity. Quantifying this sensitivity requires a detailed understanding of photon emission and jet-medium interaction in a non-equilibrium plasma. Up to now, such an understanding has been hindered by plasma instabilities which arise out of equilibrium and lead to spurious divergences when evaluating the rate of interaction of hard probes with the plasma. In this paper, we show that taking into account the time evolution of an unstable plasma cures these divergences. We calculate the time evolution of gluon two-point correlators in a setup with small initial momentum anisotropy and show that the gluon occupation density grows exponentially at early times. Based on this calculation, we argue for a phenomenological prescription where instability poles are subtracted. Finally, we show that in the Abelian case instability fields do not affect medium-induced photon emission to our order of approximation.
[ { "created": "Mon, 7 Dec 2020 12:45:28 GMT", "version": "v1" } ]
2021-09-10
[ [ "Hauksson", "Sigtryggur", "" ], [ "Jeon", "Sangyong", "" ], [ "Gale", "Charles", "" ] ]
Penetrating probes in heavy-ion collisions, like jets and photons, are sensitive to the transport coefficients of the produced quark-gluon plasma, such as shear and bulk viscosity. Quantifying this sensitivity requires a detailed understanding of photon emission and jet-medium interaction in a non-equilibrium plasma. Up to now, such an understanding has been hindered by plasma instabilities which arise out of equilibrium and lead to spurious divergences when evaluating the rate of interaction of hard probes with the plasma. In this paper, we show that taking into account the time evolution of an unstable plasma cures these divergences. We calculate the time evolution of gluon two-point correlators in a setup with small initial momentum anisotropy and show that the gluon occupation density grows exponentially at early times. Based on this calculation, we argue for a phenomenological prescription where instability poles are subtracted. Finally, we show that in the Abelian case instability fields do not affect medium-induced photon emission to our order of approximation.
1011.1909
G\'abor Somogyi
Paolo Bolzoni, Gabor Somogyi, Zoltan Trocsanyi
A subtraction scheme for computing QCD jet cross sections at NNLO: integrating the iterated singly-unresolved subtraction terms
83 pages, one reference added, typos corrected, agrees with published version
JHEP 1101:059,2011
10.1007/JHEP01(2011)059
DESY 10-191, SFB/CPP-10-106
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform the integration of all iterated singly-unresolved subtraction terms, as defined in ref. [1], over the two-particle factorized phase space. We also sum over the unresolved parton flavours. The final result can be written as a convolution (in colour space) of the Born cross section and an insertion operator. We spell out the insertion operator in terms of 24 basic integrals that are defined explicitly. We compute the coefficients of the Laurent-expansion of these integrals in two different ways, with the method of Mellin-Barnes representations and sector decomposition. Finally, we present the Laurent-expansion of the full insertion operator for the specific examples of electron-positron annihilation into two and three jets.
[ { "created": "Mon, 8 Nov 2010 21:00:36 GMT", "version": "v1" }, { "created": "Thu, 27 Jan 2011 14:35:04 GMT", "version": "v2" } ]
2011-05-10
[ [ "Bolzoni", "Paolo", "" ], [ "Somogyi", "Gabor", "" ], [ "Trocsanyi", "Zoltan", "" ] ]
We perform the integration of all iterated singly-unresolved subtraction terms, as defined in ref. [1], over the two-particle factorized phase space. We also sum over the unresolved parton flavours. The final result can be written as a convolution (in colour space) of the Born cross section and an insertion operator. We spell out the insertion operator in terms of 24 basic integrals that are defined explicitly. We compute the coefficients of the Laurent-expansion of these integrals in two different ways, with the method of Mellin-Barnes representations and sector decomposition. Finally, we present the Laurent-expansion of the full insertion operator for the specific examples of electron-positron annihilation into two and three jets.
0907.3416
Victor Goncalves
M.A. Betemps, V.P. Goncalves, J. T. de Santana Amaral
Testing Non-linear Evolution with Running Coupling Corrections in $ep$ and $pp$ collisions
19 pages, 4 figures. Version to be published in European Physical Journal C
Eur.Phys.J.C66:137-146,2010
10.1140/epjc/s10052-009-1225-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The perturbative QCD predicts that the growth of the gluon density at small-$x$ (high energies) should saturate, forming a Color Glass Condensate (CGC), which is described in mean field approximation by the Balitsky-Kovchegov (BK) equation. Recently, the next-to-leading order corrections for the BK equation were derived and a global fit of the inclusive $ep$ HERA data was performed, resulting in a parameterization for the forward scattering amplitude. In this paper we compare this parameterization with the predictions of other phenomenological models and investigate the saturation physics in diffractive deep inelastic electron-proton scattering and in the forward hadron production in $pp$ collisions. Our results demonstrate that the running coupling BK solution is able to describe these observables.
[ { "created": "Mon, 20 Jul 2009 14:52:45 GMT", "version": "v1" }, { "created": "Mon, 23 Nov 2009 12:27:52 GMT", "version": "v2" } ]
2014-11-20
[ [ "Betemps", "M. A.", "" ], [ "Goncalves", "V. P.", "" ], [ "Amaral", "J. T. de Santana", "" ] ]
The perturbative QCD predicts that the growth of the gluon density at small-$x$ (high energies) should saturate, forming a Color Glass Condensate (CGC), which is described in mean field approximation by the Balitsky-Kovchegov (BK) equation. Recently, the next-to-leading order corrections for the BK equation were derived and a global fit of the inclusive $ep$ HERA data was performed, resulting in a parameterization for the forward scattering amplitude. In this paper we compare this parameterization with the predictions of other phenomenological models and investigate the saturation physics in diffractive deep inelastic electron-proton scattering and in the forward hadron production in $pp$ collisions. Our results demonstrate that the running coupling BK solution is able to describe these observables.
1710.08239
Javier Vijande Asenjo
J.-M. Richard, A. Valcarce, J. Vijande
Stable heavy pentaquarks in constituent models
Five pages, three figures. To be published in Phys. Lett. B
null
10.1016/j.physletb.2017.10.036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that standard constituent quark models produce $(\bar c c qqq)$ hidden-charm pentaquarks, where $c$ denotes the charmed quark and $q$ a light quark, which lie below the lowest threshold for spontaneous dissociation and thus are stable in the limit where the internal $\bar c c$ annihilation is neglected. The binding is a cooperative effect of the chromoelectric and chromomagnetic components of the interaction, and it disappears in the static limit with a pure chromoelectric potential. Their wave function contains color sextet and color octet configurations for the subsystems and can hardly be reduced to a molecular state made of two interacting hadrons. These pentaquark states could be searched for in the experiments having discovered or confirmed the hidden-charm meson and baryon resonances.
[ { "created": "Mon, 23 Oct 2017 12:42:04 GMT", "version": "v1" } ]
2017-11-22
[ [ "Richard", "J. -M.", "" ], [ "Valcarce", "A.", "" ], [ "Vijande", "J.", "" ] ]
It is shown that standard constituent quark models produce $(\bar c c qqq)$ hidden-charm pentaquarks, where $c$ denotes the charmed quark and $q$ a light quark, which lie below the lowest threshold for spontaneous dissociation and thus are stable in the limit where the internal $\bar c c$ annihilation is neglected. The binding is a cooperative effect of the chromoelectric and chromomagnetic components of the interaction, and it disappears in the static limit with a pure chromoelectric potential. Their wave function contains color sextet and color octet configurations for the subsystems and can hardly be reduced to a molecular state made of two interacting hadrons. These pentaquark states could be searched for in the experiments having discovered or confirmed the hidden-charm meson and baryon resonances.
hep-ph/0408135
Shunzo Kumano
M. Hirai, S. Kumano, and T.-H. Nagai
Nuclear corrections of parton distribution functions
1+6 pages, LaTeX, 10 eps files, espcrc2.sty, to be published in Nucl. Phys. B Supplements, Proceedings of the Third International Workshop on Neutrino-Nucleus Interactions in the Few GeV Region (NuInt04), Gran Sasso, Italy, March 17-21, 2004. Nuclear PDF library is available at http://hs.phys.saga-u.ac.jp/nuclp.html
null
10.1016/j.nuclphysbps.2004.11.223
SAGA-HE-208-04
hep-ph hep-ex nucl-ex nucl-th
null
We report global analysis results of experimental data for nuclear structure-function ratios F_2^A/F_2^{A'} and proton-nucleus Drell-Yan cross-section ratios sigma_{DY}^{pA}/sigma_{DY}^{pA'} in order to determine optimum parton distribution functions (PDFs) in nuclei. An important point of this analysis is to show uncertainties of the distributions by the Hessian method. The results indicate that the uncertainties are large for gluon distributions in the whole x region and for antiquark distributions at x>0.2. We provide a code for calculating any nuclear PDFs at given x and Q^2 for general users. They can be used for calculating high-energy nuclear reactions including neutrino-nucleus interactions, which are discussed at this workshop.
[ { "created": "Wed, 11 Aug 2004 01:09:02 GMT", "version": "v1" } ]
2009-11-10
[ [ "Hirai", "M.", "" ], [ "Kumano", "S.", "" ], [ "Nagai", "T. -H.", "" ] ]
We report global analysis results of experimental data for nuclear structure-function ratios F_2^A/F_2^{A'} and proton-nucleus Drell-Yan cross-section ratios sigma_{DY}^{pA}/sigma_{DY}^{pA'} in order to determine optimum parton distribution functions (PDFs) in nuclei. An important point of this analysis is to show uncertainties of the distributions by the Hessian method. The results indicate that the uncertainties are large for gluon distributions in the whole x region and for antiquark distributions at x>0.2. We provide a code for calculating any nuclear PDFs at given x and Q^2 for general users. They can be used for calculating high-energy nuclear reactions including neutrino-nucleus interactions, which are discussed at this workshop.
2303.13329
Qiang Zhao
Ming-Xiao Duan, Lin Qiu, Xi-Zhe Ling, and Qiang Zhao
Predictions for feed-down enhancements at the $\Lambda_c \bar{D}$ and $\Lambda_c \bar{D}^*$ thresholds via the triangle and box singularities
Revtex, 6 pages, 5 figures; Comments are welcome
null
null
null
hep-ph hep-ex
http://creativecommons.org/publicdomain/zero/1.0/
We demonstrate that triangle singularity (TS) and box singularity (BS) mechanisms can produce unique narrow enhancements at the $\Lambda_c\bar{D}$ and $\Lambda_c\bar{D}^*$ thresholds in the invariant mass spectra of $J/\psi p$ and $J/\psi p\pi$, respectively. Taking into account that such mechanisms only depend on the initial $\Sigma_c^{(*)}\bar{D}^{(*)}$ interactions near threshold within the TS or BS kinematic regimes, the $\Lambda_c\bar{D}$ and $\Lambda_c\bar{D}^*$ threshold enhancements can be regarded as a feed-down phenomenon originated from both the heavier pentaquark decays and the $\Sigma_c^{(*)}\bar{D}^{(*)}$ scatterings from the continuum. A search for these structures in the $J/\psi p$ and $J/\psi p\pi$ spectra in both exclusive and semi-inclusive processes will provide a smoking-gun evidence for the hadronic molecule nature of those observed pentaquarks and clarify the role played by the TS and BS in the near-threshold dynamics.
[ { "created": "Thu, 23 Mar 2023 15:12:31 GMT", "version": "v1" } ]
2023-03-24
[ [ "Duan", "Ming-Xiao", "" ], [ "Qiu", "Lin", "" ], [ "Ling", "Xi-Zhe", "" ], [ "Zhao", "Qiang", "" ] ]
We demonstrate that triangle singularity (TS) and box singularity (BS) mechanisms can produce unique narrow enhancements at the $\Lambda_c\bar{D}$ and $\Lambda_c\bar{D}^*$ thresholds in the invariant mass spectra of $J/\psi p$ and $J/\psi p\pi$, respectively. Taking into account that such mechanisms only depend on the initial $\Sigma_c^{(*)}\bar{D}^{(*)}$ interactions near threshold within the TS or BS kinematic regimes, the $\Lambda_c\bar{D}$ and $\Lambda_c\bar{D}^*$ threshold enhancements can be regarded as a feed-down phenomenon originated from both the heavier pentaquark decays and the $\Sigma_c^{(*)}\bar{D}^{(*)}$ scatterings from the continuum. A search for these structures in the $J/\psi p$ and $J/\psi p\pi$ spectra in both exclusive and semi-inclusive processes will provide a smoking-gun evidence for the hadronic molecule nature of those observed pentaquarks and clarify the role played by the TS and BS in the near-threshold dynamics.
hep-ph/9407215
null
F. Zwirner
Beyond the MSSM
12 A4-pages, no figures (to be LATEXed twice), preprint CERN-TH.7325/94
null
null
null
hep-ph
null
To increase the predictivity of the Minimal Supersymmetric Standard Model (MSSM), one needs to go to an underlying, more fundamental theory, where at least some of the many MSSM parameters can be determined by symmetries or by dynamics. Progress may come from four-dimensional superstring solutions and their effective supergravities. Summarizing some recent work, we introduce a class of `large-hierarchy-compatible' (LHC) models that could naturally embed a stable hierarchy m_Z ~ m_{3/2} << \mpl. We discuss how in LHC models one may determine: 1) the explicit mass terms of the MSSM, as functions of the gravitino mass; 2) the scales of gauge and supersymmetry breaking, m_Z and m_{3/2}; 3) the heavy-fermion masses. Based on talks given at: the Second IFT Workshop on Yukawa Couplings, Gainesville, Florida, USA, 11--13 February 1994; the XXIXth Rencontres de Moriond, M\'eribel, France, 12--19 March 1994; the First International Conference on Phenomenology of Unification from Present to Future, Rome, Italy, 23--26 March 1994.
[ { "created": "Mon, 4 Jul 1994 07:41:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zwirner", "F.", "" ] ]
To increase the predictivity of the Minimal Supersymmetric Standard Model (MSSM), one needs to go to an underlying, more fundamental theory, where at least some of the many MSSM parameters can be determined by symmetries or by dynamics. Progress may come from four-dimensional superstring solutions and their effective supergravities. Summarizing some recent work, we introduce a class of `large-hierarchy-compatible' (LHC) models that could naturally embed a stable hierarchy m_Z ~ m_{3/2} << \mpl. We discuss how in LHC models one may determine: 1) the explicit mass terms of the MSSM, as functions of the gravitino mass; 2) the scales of gauge and supersymmetry breaking, m_Z and m_{3/2}; 3) the heavy-fermion masses. Based on talks given at: the Second IFT Workshop on Yukawa Couplings, Gainesville, Florida, USA, 11--13 February 1994; the XXIXth Rencontres de Moriond, M\'eribel, France, 12--19 March 1994; the First International Conference on Phenomenology of Unification from Present to Future, Rome, Italy, 23--26 March 1994.
1508.00266
Alexander Silenko
A. J. Silenko
Quantum-Mechanical Description of Spin-1/2 Particles and Nuclei Channeled in Bent Crystals
17 pages
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2015, Volume 9, Issue 2, pp 272-279
10.1134/S1027451015020172
null
hep-ph cond-mat.other gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
General quantum-mechanical description of relativistic particles and nuclei with spin 1/2 channeled in bent crystals is performed with the use of the cylindrical coordinate system. The previously derived Dirac equation in this system is added by terms characterizing anomalous magnetic and electric dipole moments. A transformation to the Foldy-Wouthuysen representation, a derivation of the quantum-mechanical equations of motion for particles and their spins, and a determination of classical limit of these equations are fulfilled in the general case. A physical nature of main peculiarities of description of particles and nuclei in the cylindrical coordinate system is ascertained.
[ { "created": "Sun, 2 Aug 2015 17:55:30 GMT", "version": "v1" } ]
2015-08-04
[ [ "Silenko", "A. J.", "" ] ]
General quantum-mechanical description of relativistic particles and nuclei with spin 1/2 channeled in bent crystals is performed with the use of the cylindrical coordinate system. The previously derived Dirac equation in this system is added by terms characterizing anomalous magnetic and electric dipole moments. A transformation to the Foldy-Wouthuysen representation, a derivation of the quantum-mechanical equations of motion for particles and their spins, and a determination of classical limit of these equations are fulfilled in the general case. A physical nature of main peculiarities of description of particles and nuclei in the cylindrical coordinate system is ascertained.
hep-ph/9210220
Andreas Wirzba
A. Wirzba
The Cheshire Cat Bag Model: Color Anomaly and $\eta'$ Properties
7 pages, LaTeX, Nordita - 92/68 N
Nucl.Phys. A553 (1993) 675c-680c
10.1016/0375-9474(93)90677-P
null
hep-ph nucl-th
null
We show that color can leak from a QCD bag if we allow for pseudoscalar isoscalar singlet ($\eta'$) coupling at the surface. To enforce total confinement of color an additional boundary term is suggested. New relations between the $\eta'$ mass and decay constant and the QCD gluon condensates are derived and compared with the empirical parameters.
[ { "created": "Thu, 8 Oct 1992 14:42:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Wirzba", "A.", "" ] ]
We show that color can leak from a QCD bag if we allow for pseudoscalar isoscalar singlet ($\eta'$) coupling at the surface. To enforce total confinement of color an additional boundary term is suggested. New relations between the $\eta'$ mass and decay constant and the QCD gluon condensates are derived and compared with the empirical parameters.
1301.1567
Martin Schumacher
Martin Schumacher, Michael D. Scadron
Dispersion theory of nucleon Compton scattering and polarizabilities
null
Fortschr. Phys. 61. No 7-8,703-741 (2013)
10.1002/prop.201300007
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A status report on the topic Compton scattering and polarizabilities is presented with emphasis on the scalar t-channel as entering into dispersion theory. Precise values for the polarizabilities are obtained leading to $\alpha_p = 12.0\pm 0.6$ $(12.0)$, $\beta_p=1.9\mp 0.6$ $(1.9)$, $\alpha_n= 12.5\pm 1.7$ $(13.4)$, $\beta_n= 2.7 \mp 1.8$ $(1.8)$ in units of $10^{-4}$ fm$^3$ and $\gamma^{(p)}_\pi = -36.4 \pm 1.5$ $(-36.6)$, $\gamma^{(n)}_\pi = 58.6 \pm 4.0$ $(58.3)$, $(\gamma^{(p)}_0= -0.58\pm 0.20)$, $(\gamma^{(n)}_0 = +0.38\pm 0.22)$ in units of $10^{-4}$ fm$^4$, for the proton (p) and neutron (n), respectively. The data given with an error are {\it recommended} experimental values with updates compared to [1] where necessary, the data in parentheses are predicted values. These predicted values are not contained in [1], but are the result of a newly developed analysis which is the main topic of the present paper. The most important recent discovery is that the largest part of the electric polarizability and the total diamagnetic polarizability of the nucleon are properties of the $\sigma$ meson as part of the constituent-quark structure, as expected from the mechanism of chiral symmetry breaking. This view is supported by an experiment on Compton scattering by the proton carried out in the second resonance region, where a large contribution from the $\sigma$ meson enters into the scattering amplitudes. This experiment led to a determination of the mass of the $\sigma$ meson of $m_\sigma = 600 \pm 70$ MeV. From the experimental $\alpha_p$ and predicted differences $(\alpha_n - \alpha_p)$ neutron polarizabilities in the range $\alpha_n= 12.0 - 13.4$ are predicted, where the uncertainties are related to the $f_0(980)$ and $a_0(980)$ scalar mesons.
[ { "created": "Tue, 8 Jan 2013 15:40:58 GMT", "version": "v1" }, { "created": "Sat, 27 Apr 2013 14:06:04 GMT", "version": "v2" } ]
2013-06-26
[ [ "Schumacher", "Martin", "" ], [ "Scadron", "Michael D.", "" ] ]
A status report on the topic Compton scattering and polarizabilities is presented with emphasis on the scalar t-channel as entering into dispersion theory. Precise values for the polarizabilities are obtained leading to $\alpha_p = 12.0\pm 0.6$ $(12.0)$, $\beta_p=1.9\mp 0.6$ $(1.9)$, $\alpha_n= 12.5\pm 1.7$ $(13.4)$, $\beta_n= 2.7 \mp 1.8$ $(1.8)$ in units of $10^{-4}$ fm$^3$ and $\gamma^{(p)}_\pi = -36.4 \pm 1.5$ $(-36.6)$, $\gamma^{(n)}_\pi = 58.6 \pm 4.0$ $(58.3)$, $(\gamma^{(p)}_0= -0.58\pm 0.20)$, $(\gamma^{(n)}_0 = +0.38\pm 0.22)$ in units of $10^{-4}$ fm$^4$, for the proton (p) and neutron (n), respectively. The data given with an error are {\it recommended} experimental values with updates compared to [1] where necessary, the data in parentheses are predicted values. These predicted values are not contained in [1], but are the result of a newly developed analysis which is the main topic of the present paper. The most important recent discovery is that the largest part of the electric polarizability and the total diamagnetic polarizability of the nucleon are properties of the $\sigma$ meson as part of the constituent-quark structure, as expected from the mechanism of chiral symmetry breaking. This view is supported by an experiment on Compton scattering by the proton carried out in the second resonance region, where a large contribution from the $\sigma$ meson enters into the scattering amplitudes. This experiment led to a determination of the mass of the $\sigma$ meson of $m_\sigma = 600 \pm 70$ MeV. From the experimental $\alpha_p$ and predicted differences $(\alpha_n - \alpha_p)$ neutron polarizabilities in the range $\alpha_n= 12.0 - 13.4$ are predicted, where the uncertainties are related to the $f_0(980)$ and $a_0(980)$ scalar mesons.
0910.4349
Chong Sheng Li
Jun Gao, Chong Sheng Li, Jia Jun Zhang and Hua Xing Zhu
Next-to-leading order QCD corrections to the single top quark production via model-independent t-q-g flavor-changing neutral-current couplings at hadron colliders
minor changes, version published in PRD
Phys.Rev.D80:114017,2009
10.1103/PhysRevD.80.114017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the calculations of the complete next-to-leading order (NLO) QCD effects on the single top productions induced by model-independent $tqg$ flavor-changing neutral-current couplings at hadron colliders. Our results show that, for the $tcg$ coupling the NLO QCD corrections can enhance the total cross sections by about 60% and 30%, and for the $tug$ coupling by about 50% and 20% at the Tevatron and LHC, respectively, which means that the NLO corrections can increase the experimental sensitivity to the FCNC couplings by about 10%$-$30%. Moreover, the NLO corrections reduce the dependence of the total cross sections on the renormalization or factorization scale significantly, which lead to increased confidence on the theoretical predictions. Besides, we also evaluate the NLO corrections to several important kinematic distributions, and find that for most of them the NLO corrections are almost the same and do not change the shape of the distributions.
[ { "created": "Thu, 22 Oct 2009 15:21:53 GMT", "version": "v1" }, { "created": "Mon, 26 Oct 2009 11:15:32 GMT", "version": "v2" }, { "created": "Fri, 25 Dec 2009 12:59:07 GMT", "version": "v3" } ]
2009-12-31
[ [ "Gao", "Jun", "" ], [ "Li", "Chong Sheng", "" ], [ "Zhang", "Jia Jun", "" ], [ "Zhu", "Hua Xing", "" ] ]
We present the calculations of the complete next-to-leading order (NLO) QCD effects on the single top productions induced by model-independent $tqg$ flavor-changing neutral-current couplings at hadron colliders. Our results show that, for the $tcg$ coupling the NLO QCD corrections can enhance the total cross sections by about 60% and 30%, and for the $tug$ coupling by about 50% and 20% at the Tevatron and LHC, respectively, which means that the NLO corrections can increase the experimental sensitivity to the FCNC couplings by about 10%$-$30%. Moreover, the NLO corrections reduce the dependence of the total cross sections on the renormalization or factorization scale significantly, which lead to increased confidence on the theoretical predictions. Besides, we also evaluate the NLO corrections to several important kinematic distributions, and find that for most of them the NLO corrections are almost the same and do not change the shape of the distributions.
2312.17685
Roman Poberezhnyuk
Roman Poberezhnyuk, Oleh Savchuk, Volodymyr Vovchenko, Volodymyr Kuznietsov, Jan Steinheimer, Mark Gorenstein, Horst Stoecker
Spinodal enhancement of fluctuations in nucleus-nucleus collisions
4 pages, 2 figures. Proceedings of the XXXth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2023), Houston, Texas, USA, September 3-9, 2023
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Subensemble Acceptance Method (SAM) [1,2] is an essential link between measured event-by-event fluctuations and their grand canonical theoretical predictions such as lattice QCD. The method allows quantifying the global conservation law effects in fluctuations. In its basic formulation, SAM requires a sufficiently large system such as created in central nucleus-nucleus collisions and sufficient space-momentum correlations. Directly in the spinodal region of the First Order Phase Transition (FOPT) different approximations should be used that account for finite size effects. Thus, we present the generalization of SAM applicable in both the pure phases, metastable and unstable regions of the phase diagram [3]. Obtained analytic formulas indicate the enhancement of fluctuations due to crossing the spinodal region of FOPT and are tested using molecular dynamics simulations. A rather good agreement is observed. Using transport model calculations with interaction potential we show that the spinodal enhancement of fluctuations survives till the later stages of collision via the memory effect [4]. However, at low collision energies the space-momentum correlation is not strong enough for this signal to be transferred to second and third order cumulants measured in momentum subspace. This result agrees well with recent HADES data on proton number fluctuations at $\sqrt{s_{NN}}=2.4$ GeV which are found to be consistent with the binomial momentum space acceptance [5].
[ { "created": "Fri, 29 Dec 2023 17:06:16 GMT", "version": "v1" } ]
2024-01-01
[ [ "Poberezhnyuk", "Roman", "" ], [ "Savchuk", "Oleh", "" ], [ "Vovchenko", "Volodymyr", "" ], [ "Kuznietsov", "Volodymyr", "" ], [ "Steinheimer", "Jan", "" ], [ "Gorenstein", "Mark", "" ], [ "Stoecker", "Horst", ...
Subensemble Acceptance Method (SAM) [1,2] is an essential link between measured event-by-event fluctuations and their grand canonical theoretical predictions such as lattice QCD. The method allows quantifying the global conservation law effects in fluctuations. In its basic formulation, SAM requires a sufficiently large system such as created in central nucleus-nucleus collisions and sufficient space-momentum correlations. Directly in the spinodal region of the First Order Phase Transition (FOPT) different approximations should be used that account for finite size effects. Thus, we present the generalization of SAM applicable in both the pure phases, metastable and unstable regions of the phase diagram [3]. Obtained analytic formulas indicate the enhancement of fluctuations due to crossing the spinodal region of FOPT and are tested using molecular dynamics simulations. A rather good agreement is observed. Using transport model calculations with interaction potential we show that the spinodal enhancement of fluctuations survives till the later stages of collision via the memory effect [4]. However, at low collision energies the space-momentum correlation is not strong enough for this signal to be transferred to second and third order cumulants measured in momentum subspace. This result agrees well with recent HADES data on proton number fluctuations at $\sqrt{s_{NN}}=2.4$ GeV which are found to be consistent with the binomial momentum space acceptance [5].
hep-ph/0610243
Rouzbeh Allahverdi
Rouzbeh Allahverdi, Asko Jokinen, Anupam Mazumdar
Sub-eV Hubble scale inflation within gauge mediated supersymmetry breaking
4 revtex pages
null
null
null
hep-ph astro-ph gr-qc hep-th
null
Minimal Supersymmetric Standard Model with gauge mediated supersymmetry breaking has all the necessary ingredients for a successful sub-eV Hubble scale inflation $H_{\rm inf} \sim 10^{-3}-10^{-1}$ eV. The model generates the right amplitude for scalar density perturbations and a spectral tilt within the range, $0.90 \leq n_s \leq 1$. The reheat temperature is $T_{\rm R} \ls 10$ TeV, which strongly prefers electroweak baryogenesis and creates the right abundance of gravitinos with a mass $m_{3/2} \gs 100$ keV to be the dark matter.
[ { "created": "Wed, 18 Oct 2006 20:51:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Allahverdi", "Rouzbeh", "" ], [ "Jokinen", "Asko", "" ], [ "Mazumdar", "Anupam", "" ] ]
Minimal Supersymmetric Standard Model with gauge mediated supersymmetry breaking has all the necessary ingredients for a successful sub-eV Hubble scale inflation $H_{\rm inf} \sim 10^{-3}-10^{-1}$ eV. The model generates the right amplitude for scalar density perturbations and a spectral tilt within the range, $0.90 \leq n_s \leq 1$. The reheat temperature is $T_{\rm R} \ls 10$ TeV, which strongly prefers electroweak baryogenesis and creates the right abundance of gravitinos with a mass $m_{3/2} \gs 100$ keV to be the dark matter.
1610.03020
Alexander Kovner
Tolga Altinoluk, Nestor Armesto, Guillaume Beuf, Alex Kovner and Michael Lublinsky
Quark correlations in the Color Glass Condensate: Pauli blocking and the ridge
32 pages, 9 figures; explanations added, some algebraic errors corrected, results unchanged, version accepted for publication in PRD
Phys. Rev. D 95, 034025 (2017)
10.1103/PhysRevD.95.034025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider, for the first time, correlations between produced quarks in p-A collisions in the framework of the Color Glass Condensate. We find a quark-quark ridge that shows a dip at $\Delta\eta\sim 2$ relative to the gluon-gluon ridge. The origin of this dip is the short range (in rapidity) Pauli blocking experienced by quarks in the wave function of the incoming projectile. We observe that these correlations, present in the initial state, survive the scattering process. We suggest that this effect may be observable in open charm-open charm correlations at the Large Hadron Collider.
[ { "created": "Mon, 10 Oct 2016 18:24:15 GMT", "version": "v1" }, { "created": "Fri, 17 Feb 2017 14:49:38 GMT", "version": "v2" } ]
2017-03-01
[ [ "Altinoluk", "Tolga", "" ], [ "Armesto", "Nestor", "" ], [ "Beuf", "Guillaume", "" ], [ "Kovner", "Alex", "" ], [ "Lublinsky", "Michael", "" ] ]
We consider, for the first time, correlations between produced quarks in p-A collisions in the framework of the Color Glass Condensate. We find a quark-quark ridge that shows a dip at $\Delta\eta\sim 2$ relative to the gluon-gluon ridge. The origin of this dip is the short range (in rapidity) Pauli blocking experienced by quarks in the wave function of the incoming projectile. We observe that these correlations, present in the initial state, survive the scattering process. We suggest that this effect may be observable in open charm-open charm correlations at the Large Hadron Collider.
hep-ph/0612288
Brett D. Altschul
Brett Altschul
Bounds on Spin-Dependent Lorentz Violation From Inverse Compton Observations
10 pages
Phys.Rev.D75:041301,2007
10.1103/PhysRevD.75.041301
IUHET-503
hep-ph
null
Some of the best bounds on possible Lorentz violation in the electron sector come from observations of high-energy astrophysical phenomena. Using measurements of TeV inverse Compton radiation from a number of sources, we place the first bounds--at the 10^(-15) level--on seven of the electron d coefficients.
[ { "created": "Thu, 21 Dec 2006 20:18:45 GMT", "version": "v1" } ]
2008-11-26
[ [ "Altschul", "Brett", "" ] ]
Some of the best bounds on possible Lorentz violation in the electron sector come from observations of high-energy astrophysical phenomena. Using measurements of TeV inverse Compton radiation from a number of sources, we place the first bounds--at the 10^(-15) level--on seven of the electron d coefficients.
hep-ph/0303185
Anton Rebhan
J.-P. Blaizot, E. Iancu, A. Rebhan
Thermodynamics of the high-temperature quark-gluon plasma
Review for "Quark-Gluon Plasma 3", eds. R.C. Hwa and X.-N. Wang, World Scientific, Singapore. 63 pages, 21 figures. v2: minor corrections and 2 references added
null
10.1142/9789812795533_0002
SACLAY-T03/26, TUW-03-04
hep-ph
null
We review the various methods which have been employed recently to describe the thermodynamics of the high temperature quark-gluon plasma using weak coupling techniques, and we compare their results with those of most recent lattice gauge calculations. Many of the difficulties encountered with perturbation theory at finite temperature are in fact not specific to QCD but are present in any field theory at finite temperature and will be discussed first in the simple example of the scalar field theory. We discuss the merits and limitations of various techniques which have been used to go beyond perturbation theory in the soft sector, such as dimensional reduction, screened perturbation theory or hard-thermal-loop perturbation theory, and Phi-derivable approximations. In the last part of the review, we focus on the later, which lead to a remarkably simple expression for the entropy of the quark-gluon plasma. When complemented with further, physically motivated, approximations, this approach reproduces accurately the entropy obtained from lattice gauge calculations at temperatures above 2.5 T_c, where T_c is the deconfinement temperature. This calculation thus provides also support to the physical picture of the quark-gluon plasma as a gas of weakly interacting quasiparticles.
[ { "created": "Fri, 21 Mar 2003 18:14:05 GMT", "version": "v1" }, { "created": "Thu, 27 Mar 2003 16:44:06 GMT", "version": "v2" } ]
2016-11-23
[ [ "Blaizot", "J. -P.", "" ], [ "Iancu", "E.", "" ], [ "Rebhan", "A.", "" ] ]
We review the various methods which have been employed recently to describe the thermodynamics of the high temperature quark-gluon plasma using weak coupling techniques, and we compare their results with those of most recent lattice gauge calculations. Many of the difficulties encountered with perturbation theory at finite temperature are in fact not specific to QCD but are present in any field theory at finite temperature and will be discussed first in the simple example of the scalar field theory. We discuss the merits and limitations of various techniques which have been used to go beyond perturbation theory in the soft sector, such as dimensional reduction, screened perturbation theory or hard-thermal-loop perturbation theory, and Phi-derivable approximations. In the last part of the review, we focus on the later, which lead to a remarkably simple expression for the entropy of the quark-gluon plasma. When complemented with further, physically motivated, approximations, this approach reproduces accurately the entropy obtained from lattice gauge calculations at temperatures above 2.5 T_c, where T_c is the deconfinement temperature. This calculation thus provides also support to the physical picture of the quark-gluon plasma as a gas of weakly interacting quasiparticles.