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1409.3661
I-chin Wang
Guo-Chin Liu and Kin-Wang Ng and I-Chin Wang
Naturally large tensor-to-scalar ratio in inflation
6 pages, 3 figures
Phys.Rev.D 90, 103531(2014)
10.1103/PhysRevD.90.103531
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, BICEP2 measurements of the cosmic microwave background (CMB) $B$-mode polarization at degree angular scales has indicated the presence of tensor modes with a high tensor-to-scalar ratio of $r=0.2$ when assuming nearly scale-invariant tensor and scalar spectra, although the signal may be contaminated by dust emission as implied by the recent {\em Planck} polarization data. This result is in conflict with the {\em Planck} best-fit Lambda Cold Dark Model with $r<0.11$. Due to the fact that inflaton has to be interacting with other fields so as to convert its potential energy into radiation to reheat the Universe, the interacting inflaton may result in a suppression of the scalar spectrum at large scales. This suppression has been used to explain the observed low quadrupole in the CMB anisotropy. In this paper, we show that a combination of the tensor modes measured by BICEP2 and the large-scale suppressed scalar modes contributes to the CMB anisotropy in such a way that the resultant CMB anisotropy and polarization power spectra are consistent with both {\em Planck} and BICEP2 data. We also project our findings to cases in which $r$ may become reduced in future CMB polarization measurements.
[ { "created": "Fri, 12 Sep 2014 07:23:38 GMT", "version": "v1" }, { "created": "Fri, 17 Oct 2014 08:48:28 GMT", "version": "v2" } ]
2015-06-22
[ [ "Liu", "Guo-Chin", "" ], [ "Ng", "Kin-Wang", "" ], [ "Wang", "I-Chin", "" ] ]
Recently, BICEP2 measurements of the cosmic microwave background (CMB) $B$-mode polarization at degree angular scales has indicated the presence of tensor modes with a high tensor-to-scalar ratio of $r=0.2$ when assuming nearly scale-invariant tensor and scalar spectra, although the signal may be contaminated by dust emission as implied by the recent {\em Planck} polarization data. This result is in conflict with the {\em Planck} best-fit Lambda Cold Dark Model with $r<0.11$. Due to the fact that inflaton has to be interacting with other fields so as to convert its potential energy into radiation to reheat the Universe, the interacting inflaton may result in a suppression of the scalar spectrum at large scales. This suppression has been used to explain the observed low quadrupole in the CMB anisotropy. In this paper, we show that a combination of the tensor modes measured by BICEP2 and the large-scale suppressed scalar modes contributes to the CMB anisotropy in such a way that the resultant CMB anisotropy and polarization power spectra are consistent with both {\em Planck} and BICEP2 data. We also project our findings to cases in which $r$ may become reduced in future CMB polarization measurements.
1608.07500
Ahmed Hammad
W. Abdallah, A. Hammad, S. Khalil, S. Moretti
Search for Mono-Higgs Signals at the LHC in the B-L Supersymmetric Standard Model
16 pages and 7 figures
Phys. Rev. D 95, 055019 (2017)
10.1103/PhysRevD.95.055019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study mono-Higgs signatures emerging in the $B-L$ supersymmetric standard model induced by new channels not present in the minimal supersymmetric standard model, i.e., via topologies in which the mediator is either a heavy $Z'$, with mass of ${\cal O}(2~{\rm TeV})$, or an intermediate $h'$ (the lightest CP-even Higgs state of $B-L$ origin), with mass of ${\cal O}(0.2~{\rm TeV})$. The mono-Higgs probe considered is the SM-like Higgs state recently discovered at the large hadron collider, so as to enforce its mass reconstruction for background reduction purposes. With this in mind, its two cleanest signatures are selected: $\gamma\gamma$ and $ZZ^*\to 4l$ ($l=e,~\mu$). We show how both of these can be accessed with foreseen energy and luminosity options using a dedicated kinematic analysis performed in presence of partonic, showering, hadronisation and detector effects.
[ { "created": "Fri, 26 Aug 2016 16:03:49 GMT", "version": "v1" } ]
2017-03-29
[ [ "Abdallah", "W.", "" ], [ "Hammad", "A.", "" ], [ "Khalil", "S.", "" ], [ "Moretti", "S.", "" ] ]
We study mono-Higgs signatures emerging in the $B-L$ supersymmetric standard model induced by new channels not present in the minimal supersymmetric standard model, i.e., via topologies in which the mediator is either a heavy $Z'$, with mass of ${\cal O}(2~{\rm TeV})$, or an intermediate $h'$ (the lightest CP-even Higgs state of $B-L$ origin), with mass of ${\cal O}(0.2~{\rm TeV})$. The mono-Higgs probe considered is the SM-like Higgs state recently discovered at the large hadron collider, so as to enforce its mass reconstruction for background reduction purposes. With this in mind, its two cleanest signatures are selected: $\gamma\gamma$ and $ZZ^*\to 4l$ ($l=e,~\mu$). We show how both of these can be accessed with foreseen energy and luminosity options using a dedicated kinematic analysis performed in presence of partonic, showering, hadronisation and detector effects.
hep-ph/9304276
Ed Stoeffhaas
M.B. Gay Ducati, F. Halzen, and A.A. Natale
Diffraction and the Gluon Mass
10 pages, Latex, 3 figures available by fax or conventional mail. MAD/PH/750
Phys.Rev.D48:2324-2328,1993
10.1103/PhysRevD.48.2324
null
hep-ph
null
We recently proposed a QCD-Pomeron described by the exchange of two non-perturbative gluons characterized by a dynamically generated gluon mass. It is here shown that data on elastic scattering, exclusive $\rho$ production in deep inelastic scattering and the $J/\Psi$-nucleon total cross-section can be successfully described in terms of a single gluon mass $m_g\simeq0.37$~GeV. We observe that the total cross sections of hadrons with small radii, such as $J/\Psi$, have a marked dependence on the effective gluon mass.
[ { "created": "Tue, 20 Apr 1993 15:52:30 GMT", "version": "v1" } ]
2011-07-19
[ [ "Ducati", "M. B. Gay", "" ], [ "Halzen", "F.", "" ], [ "Natale", "A. A.", "" ] ]
We recently proposed a QCD-Pomeron described by the exchange of two non-perturbative gluons characterized by a dynamically generated gluon mass. It is here shown that data on elastic scattering, exclusive $\rho$ production in deep inelastic scattering and the $J/\Psi$-nucleon total cross-section can be successfully described in terms of a single gluon mass $m_g\simeq0.37$~GeV. We observe that the total cross sections of hadrons with small radii, such as $J/\Psi$, have a marked dependence on the effective gluon mass.
2004.13568
Qi-Fang L\"u
Wei Liang and Qi-Fang L\"u
The newly observed $\Lambda_b(6072)^0$ structure and its $\rho-$mode nonstrange partners
8 pages, 4 figures, comments and suggestions are welcome
null
10.1140/epjc/s10052-020-8274-2
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the newly observed $\Lambda_b(6072)$ structure, we investigate its strong decay behaviors under various assignments within the $^3P_0$ model. Compared with the mass and total decay width, our results suggest that the $\Lambda_b(6072)$ can be regarded as the lowest $\rho-$mode excitation in $\Lambda_b$ family. Then, the strong decays of $\rho-$mode nonstrange partners for the $\Lambda_b(6072)$ are calculated. It is found that the $J^P=5/2^-$ $\Lambda_b$ and $\Lambda_c$ states are relatively narrow, and mainly decay into the $\Sigma_b^{(*)} \pi$ and $\Sigma_c^{(*)} \pi$ final states, respectively. These two states have good potentials to be observed in future experiments, which may help us to distinguish the three-quark model and diquark model.
[ { "created": "Tue, 28 Apr 2020 14:45:38 GMT", "version": "v1" } ]
2020-08-26
[ [ "Liang", "Wei", "" ], [ "Lü", "Qi-Fang", "" ] ]
Inspired by the newly observed $\Lambda_b(6072)$ structure, we investigate its strong decay behaviors under various assignments within the $^3P_0$ model. Compared with the mass and total decay width, our results suggest that the $\Lambda_b(6072)$ can be regarded as the lowest $\rho-$mode excitation in $\Lambda_b$ family. Then, the strong decays of $\rho-$mode nonstrange partners for the $\Lambda_b(6072)$ are calculated. It is found that the $J^P=5/2^-$ $\Lambda_b$ and $\Lambda_c$ states are relatively narrow, and mainly decay into the $\Sigma_b^{(*)} \pi$ and $\Sigma_c^{(*)} \pi$ final states, respectively. These two states have good potentials to be observed in future experiments, which may help us to distinguish the three-quark model and diquark model.
hep-ph/0407320
Miguel Sanchis
Miguel A. Sanchis-Lozano
Hints of new physics in bottomonium decays and spectroscopy
4 pages, 3 EPS figures, Talk given at BEACH 2004, 27/6/04 - 3/7/04 IIT Chicago
null
10.1016/j.nuclphysbps.2005.01.034
IFIC/04-42, FTUV-04-0728
hep-ph
null
A non-standard light CP-odd Higgs boson could induce a slight (but observable) lepton universality breakdown in Upsilon leptonic decays. Moreover, the mixing between such a pseudoscalar Higgs and $\eta_b$ states might shift the mass levels of the latter, thereby changing the values of the $m_{\Upsilon(nS)}-m_{\eta_b(nS)}$ splittings predicted in the standard model. Besides, also the $\eta_b$ width could be broader than expected, with potentially negative consequences for its discovery in both $e^+e^-$ and hadron colliders.
[ { "created": "Wed, 28 Jul 2004 10:47:40 GMT", "version": "v1" }, { "created": "Wed, 11 Aug 2004 15:50:45 GMT", "version": "v2" }, { "created": "Tue, 9 Nov 2004 13:07:13 GMT", "version": "v3" } ]
2009-11-10
[ [ "Sanchis-Lozano", "Miguel A.", "" ] ]
A non-standard light CP-odd Higgs boson could induce a slight (but observable) lepton universality breakdown in Upsilon leptonic decays. Moreover, the mixing between such a pseudoscalar Higgs and $\eta_b$ states might shift the mass levels of the latter, thereby changing the values of the $m_{\Upsilon(nS)}-m_{\eta_b(nS)}$ splittings predicted in the standard model. Besides, also the $\eta_b$ width could be broader than expected, with potentially negative consequences for its discovery in both $e^+e^-$ and hadron colliders.
2103.09829
Marvin Zanke
Marvin Zanke, Martin Hoferichter, Bastian Kubis
On the transition form factors of the axial-vector resonance $f_1(1285)$ and its decay into $e^+e^-$
60 pages, 14 figures; v2: Appendix D on alternative $f_1 \to 4\pi$ mechanism added, references updated, version published in JHEP
JHEP 07 (2021) 106
10.1007/JHEP07(2021)106
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Estimating the contribution from axial-vector intermediate states to hadronic light-by-light scattering requires input on their transition form factors (TFFs). Due to the Landau-Yang theorem, any experiment sensitive to these TFFs needs to involve at least one virtual photon, which complicates their measurement. Phenomenologically, the situation is best for the $f_1(1285)$ resonance, for which information is available from $e^+e^-\to e^+e^- f_1$, $f_1\to 4\pi$, $f_1\to \rho \gamma$, $f_1\to \phi \gamma$, and $f_1\to e^+e^-$. We provide a comprehensive analysis of the $f_1$ TFFs in the framework of vector meson dominance, including short-distance constraints, to determine to which extent the three independent TFFs can be constrained from the available experimental input, a prerequisite for improved calculations of the axial-vector contribution to hadronic light-by-light scattering. In particular, we focus on the process $f_1\to e^+e^-$, evidence for which has been reported recently by SND for the first time, and discuss the impact that future improved measurements will have on the determination of the $f_1$ TFFs.
[ { "created": "Wed, 17 Mar 2021 18:00:02 GMT", "version": "v1" }, { "created": "Tue, 20 Jul 2021 10:14:11 GMT", "version": "v2" } ]
2021-07-21
[ [ "Zanke", "Marvin", "" ], [ "Hoferichter", "Martin", "" ], [ "Kubis", "Bastian", "" ] ]
Estimating the contribution from axial-vector intermediate states to hadronic light-by-light scattering requires input on their transition form factors (TFFs). Due to the Landau-Yang theorem, any experiment sensitive to these TFFs needs to involve at least one virtual photon, which complicates their measurement. Phenomenologically, the situation is best for the $f_1(1285)$ resonance, for which information is available from $e^+e^-\to e^+e^- f_1$, $f_1\to 4\pi$, $f_1\to \rho \gamma$, $f_1\to \phi \gamma$, and $f_1\to e^+e^-$. We provide a comprehensive analysis of the $f_1$ TFFs in the framework of vector meson dominance, including short-distance constraints, to determine to which extent the three independent TFFs can be constrained from the available experimental input, a prerequisite for improved calculations of the axial-vector contribution to hadronic light-by-light scattering. In particular, we focus on the process $f_1\to e^+e^-$, evidence for which has been reported recently by SND for the first time, and discuss the impact that future improved measurements will have on the determination of the $f_1$ TFFs.
hep-ph/0310301
Andre Hoang
A. H. Hoang (Munich, Max Planck Inst.)
Top Pair Production at Threshold and Effective Theories
19 pages, appolb_mod.cls, 4 postscript figures. Invited plenary talk at Cracow Epiphany Conference on Heavy Flavors, January 3-6, 2003
Acta Phys.Polon.B34:4491-4509,2003
null
MPP-2003-114
hep-ph
null
I give an introduction to the effective field theory description of top pair production at threshold in e+e- annihilation. The impact of the summation of logarithms of the top quark velocity including most recent results at next-to-next-to-leading logarithmic order is discussed.
[ { "created": "Mon, 27 Oct 2003 17:33:16 GMT", "version": "v1" } ]
2009-12-30
[ [ "Hoang", "A. H.", "", "Munich, Max Planck Inst." ] ]
I give an introduction to the effective field theory description of top pair production at threshold in e+e- annihilation. The impact of the summation of logarithms of the top quark velocity including most recent results at next-to-next-to-leading logarithmic order is discussed.
hep-ph/0111273
Balasubramanian Ananthanarayan
B. Ananthanarayan, P. N. Pandita
Reply to Comment on Infrared Fixed Point Structure in the Minimal Supersymmetric Standard Model with Baryon and Lepton Number Violation
4 pages in ReVTeX, to be published in Physical Review D
Phys.Rev. D65 (2002) 058902
10.1103/PhysRevD.65.058902
IISc-CTS-18/01
hep-ph
null
Infrared fixed points in the minimal supersymmetric standard model with baryon and lepton number violation were studied and their structure elucidated by us in Physical Review D 63 076008 (2001). Here we reply to a comment on this paper. We emphasize that our paper concentrates on the case of the only true infrared fixed point in the model, i.e. the stable nontrivial fixed point for the top- and bottom-quark Yukawa couplings and the baryon number violating coupling. For this case the comment does not affect in any manner the numerical results and conclusions derived in our paper.
[ { "created": "Thu, 22 Nov 2001 04:13:57 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ananthanarayan", "B.", "" ], [ "Pandita", "P. N.", "" ] ]
Infrared fixed points in the minimal supersymmetric standard model with baryon and lepton number violation were studied and their structure elucidated by us in Physical Review D 63 076008 (2001). Here we reply to a comment on this paper. We emphasize that our paper concentrates on the case of the only true infrared fixed point in the model, i.e. the stable nontrivial fixed point for the top- and bottom-quark Yukawa couplings and the baryon number violating coupling. For this case the comment does not affect in any manner the numerical results and conclusions derived in our paper.
hep-ph/0110197
Nikita Agasian
B.O. Kerbikov
Color Superconducting State of Quarks
17 pages, LaTeX2e, no figures
null
null
null
hep-ph
null
An introductory review of physics of color superconducting state of matter is presented. Comparison with superconductivity in electron systems reveals difficulties involved in formulating color superconductivity theory at moderately ultra-nuclear density.
[ { "created": "Mon, 15 Oct 2001 18:30:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kerbikov", "B. O.", "" ] ]
An introductory review of physics of color superconducting state of matter is presented. Comparison with superconductivity in electron systems reveals difficulties involved in formulating color superconductivity theory at moderately ultra-nuclear density.
1909.11041
Suman Chatterjee
Suman Chatterjee, Rohini Godbole, and Tuhin S. Roy
Jets with electrons from boosted top quarks
25 pages, 8 figures
JHEP 01 (2020) 170
10.1007/JHEP01(2020)170
TIFR/TH/19-33
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a method to identify jets consisting of all the visible remnants of boosted top particles when these decay semileptonically to electrons. Within these jets, the electron shower overlaps with the shower initiated by the $b$ quark, which makes the identification of the electron hard. Even if an electron inside a jet is identified, it is difficult to pinpoint whether the electron rich jet is indeed due to top quark decay or not, since the invisible neutrino carries away a nontrivial part of the energy-momentum of the original top quark. Broadly speaking, the method proposed here has three key components. It uses the distribution of energy in various parts of the detector to identify whether the observed jet is consistent with a jet containing an energetic electron. It uses the substructure of the jet to determine the momentum associated with the electron. Finally, it constructs new variables that carry tell-tale features of top quark decay kinematics using an extra ansatz that, there exists a massless invisible four-momentum \emph{roughly} collimated to the electron, which reconstructs a $W$ and a top when it is combined with the electron and the full jet respectively. We demonstrate the efficacy of this proposal using simulated data and show that our method not only reduces the backgrounds from light flavor jets, $b$ jets from QCD, and hadronic top jets, it can also tell apart jets rich in electrons but not due to top quark decays.
[ { "created": "Tue, 24 Sep 2019 16:51:45 GMT", "version": "v1" }, { "created": "Tue, 21 Jan 2020 09:13:56 GMT", "version": "v2" } ]
2020-02-03
[ [ "Chatterjee", "Suman", "" ], [ "Godbole", "Rohini", "" ], [ "Roy", "Tuhin S.", "" ] ]
We propose a method to identify jets consisting of all the visible remnants of boosted top particles when these decay semileptonically to electrons. Within these jets, the electron shower overlaps with the shower initiated by the $b$ quark, which makes the identification of the electron hard. Even if an electron inside a jet is identified, it is difficult to pinpoint whether the electron rich jet is indeed due to top quark decay or not, since the invisible neutrino carries away a nontrivial part of the energy-momentum of the original top quark. Broadly speaking, the method proposed here has three key components. It uses the distribution of energy in various parts of the detector to identify whether the observed jet is consistent with a jet containing an energetic electron. It uses the substructure of the jet to determine the momentum associated with the electron. Finally, it constructs new variables that carry tell-tale features of top quark decay kinematics using an extra ansatz that, there exists a massless invisible four-momentum \emph{roughly} collimated to the electron, which reconstructs a $W$ and a top when it is combined with the electron and the full jet respectively. We demonstrate the efficacy of this proposal using simulated data and show that our method not only reduces the backgrounds from light flavor jets, $b$ jets from QCD, and hadronic top jets, it can also tell apart jets rich in electrons but not due to top quark decays.
1702.06731
Johannes Knaute
J. Knaute, R. Yaresko, B. K\"ampfer
Holographic QCD phase diagram with critical point from Einstein-Maxwell-dilaton dynamics
extended discussions on limitations of the holographic model; typos corrected and refs added; to appear in PLB
Phys. Lett. B 778, 419 (2018)
10.1016/j.physletb.2018.01.053
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supplementing the holographic Einstein-Maxwell-dilaton model of [O. DeWolfe, S.S. Gubser, C. Rosen, Phys. Rev. D83 (2011) 086005; O. DeWolfe, S.S. Gubser, C. Rosen, Phys. Rev. D84 (2011) 126014] by input of lattice QCD data for 2+1 flavors and physical quark masses for the equation of state and quark number susceptibility at zero baryo-chemical potential we explore the resulting phase diagram over the temperature-chemical potential plane. A first-order phase transition sets in at a temperature of about 112 MeV and a baryo-chemical potential of 612 MeV. We estimate the accuracy of the critical point position in the order of approximately 5-8% by considering parameter variations and different low-temperature asymptotics for the second-order quark number susceptibility. The critical pressure as a function of the temperature has a positive slope, i.e. the entropy per baryon jumps up when crossing the phase border line from larger values of temperature/baryo-chemical potential, thus classifying the phase transition as a gas liquid one. The updated holographic model exhibits in- and outgoing isentropes in the vicinity of the first-order phase transition.
[ { "created": "Wed, 22 Feb 2017 10:09:03 GMT", "version": "v1" }, { "created": "Mon, 31 Jul 2017 16:24:56 GMT", "version": "v2" }, { "created": "Fri, 19 Jan 2018 14:45:32 GMT", "version": "v3" } ]
2018-02-06
[ [ "Knaute", "J.", "" ], [ "Yaresko", "R.", "" ], [ "Kämpfer", "B.", "" ] ]
Supplementing the holographic Einstein-Maxwell-dilaton model of [O. DeWolfe, S.S. Gubser, C. Rosen, Phys. Rev. D83 (2011) 086005; O. DeWolfe, S.S. Gubser, C. Rosen, Phys. Rev. D84 (2011) 126014] by input of lattice QCD data for 2+1 flavors and physical quark masses for the equation of state and quark number susceptibility at zero baryo-chemical potential we explore the resulting phase diagram over the temperature-chemical potential plane. A first-order phase transition sets in at a temperature of about 112 MeV and a baryo-chemical potential of 612 MeV. We estimate the accuracy of the critical point position in the order of approximately 5-8% by considering parameter variations and different low-temperature asymptotics for the second-order quark number susceptibility. The critical pressure as a function of the temperature has a positive slope, i.e. the entropy per baryon jumps up when crossing the phase border line from larger values of temperature/baryo-chemical potential, thus classifying the phase transition as a gas liquid one. The updated holographic model exhibits in- and outgoing isentropes in the vicinity of the first-order phase transition.
hep-ph/9407409
Erwin Mirkes
V. Barger, E. Mirkes, R.J.N. Phillips and T. Stelzer
Calculation of Z Plus Four Jet Production at the Tevatron
8 pages (LaTeX), MAD/PH/844, RAL-94-070, to be published in Phys. Lett. B
Phys.Lett.B338:336-340,1994
10.1016/0370-2693(94)91388-9
null
hep-ph
null
We present the first calculation of $Z+4$ jet production with heavy quark flavor identification at the Tevatron $p\bar p$ collider. The $Z + 4$ jet channel is especially interesting as a normalizer for the $W +4$ jet background to top quark signals, as a background to a possible $t\to cZ$ flavor-changing neutral-current (FCNC) decay signal, and as a background to missing-$p_T$ signals from gluino pairs. We also calculate the contributions to $W+4$ jet production from all the different heavy-flavor final states. The MADGRAPH program is used to generate all leading order subprocess helicity amplitudes. We present Monte Carlo results with separation and acceptance criteria suitable for the Tevatron experimental analyses. The dependence of the cross sections on experimental cuts and the theoretical ambiguities due to the scale dependence are discussed. The predicted ($W+4$ jet)/($Z+4$ jet) ratio is insensitive to most of these choices.
[ { "created": "Mon, 1 Aug 1994 03:12:09 GMT", "version": "v1" }, { "created": "Wed, 7 Sep 1994 20:19:53 GMT", "version": "v2" } ]
2009-09-15
[ [ "Barger", "V.", "" ], [ "Mirkes", "E.", "" ], [ "Phillips", "R. J. N.", "" ], [ "Stelzer", "T.", "" ] ]
We present the first calculation of $Z+4$ jet production with heavy quark flavor identification at the Tevatron $p\bar p$ collider. The $Z + 4$ jet channel is especially interesting as a normalizer for the $W +4$ jet background to top quark signals, as a background to a possible $t\to cZ$ flavor-changing neutral-current (FCNC) decay signal, and as a background to missing-$p_T$ signals from gluino pairs. We also calculate the contributions to $W+4$ jet production from all the different heavy-flavor final states. The MADGRAPH program is used to generate all leading order subprocess helicity amplitudes. We present Monte Carlo results with separation and acceptance criteria suitable for the Tevatron experimental analyses. The dependence of the cross sections on experimental cuts and the theoretical ambiguities due to the scale dependence are discussed. The predicted ($W+4$ jet)/($Z+4$ jet) ratio is insensitive to most of these choices.
0808.2880
Patel Bhavin Mr.
Bhavin Patel, Ajay Majethiya and P. C. Vinodkumar
Masses and Magnetic moments of Triply Heavy Flavour Baryons in Hypercentral Model
12 Pages, 1 Figure
Pramana 72:679-688,2009
10.1007/s12043-009-0061-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Triply heavy flavour baryons are studied using the hyper central description of the three-body system. The confinement potential is assumed as hyper central coulomb plus power potential with power index $p$. The ground state ($J^P={1/2}^+$ and ${3/2}^+$) masses of heavy flavour baryons are computed for different power index, $ p$ starting from 0.5 to 2.0. The predicted masses are found to attain a saturated value with respect to variation in $p$ beyond the power index $p>1.0$. Using the spin-flavour structure of the constituting quarks and by defining effective mass of the confined quarks within the baryons, the magnetic moments are computed with no additional free parameters.
[ { "created": "Thu, 21 Aug 2008 07:46:13 GMT", "version": "v1" } ]
2010-11-02
[ [ "Patel", "Bhavin", "" ], [ "Majethiya", "Ajay", "" ], [ "Vinodkumar", "P. C.", "" ] ]
Triply heavy flavour baryons are studied using the hyper central description of the three-body system. The confinement potential is assumed as hyper central coulomb plus power potential with power index $p$. The ground state ($J^P={1/2}^+$ and ${3/2}^+$) masses of heavy flavour baryons are computed for different power index, $ p$ starting from 0.5 to 2.0. The predicted masses are found to attain a saturated value with respect to variation in $p$ beyond the power index $p>1.0$. Using the spin-flavour structure of the constituting quarks and by defining effective mass of the confined quarks within the baryons, the magnetic moments are computed with no additional free parameters.
0712.0796
Enrique Fernandez-Martinez
Pilar Coloma, Andrea Donini, Enrique Fernandez-Martinez, Jacobo Lopez-Pavon
$\theta_{13}$, $\delta$ and the neutrino mass hierarchy at a $\gamma=350$ double baseline Li/B $\beta$-Beam
35 pages, 20 figures. Minor changes, matches the published version
JHEP 0805:050,2008
10.1088/1126-6708/2008/05/050
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a $\beta$-Beam facility where $^8$Li and $^8$B ions are accelerated at $\gamma = 350$, accumulated in a 10 Km storage ring and let decay, so as to produce intense $\bar \nu_e$ and $\nu_e$ beams. These beams illuminate two iron detectors located at $L \simeq 2000$ Km and $L \simeq 7000$ Km, respectively. The physics potential of this setup is analysed in full detail as a function of the flux. We find that, for the highest flux ($10 \times 10^{18}$ ion decays per year per baseline), the sensitivity to $\theta_{13}$ reaches $\sin^2 2 \theta_{13} \geq 2 \times10^{-4}$; the sign of the atmospheric mass difference can be identified, regardless of the true hierarchy, for $\sin^2 2 \theta_{13} \geq 4\times10^{-4}$; and, CP-violation can be discovered in 70% of the $\delta$-parameter space for $\sin^2 2 \theta_{13} \geq 10^{-3}$, having some sensitivity to CP-violation down to $\sin^2 2 \theta_{13} \geq 10^{-4}$ for $|\delta| \sim 90^\circ$.
[ { "created": "Wed, 5 Dec 2007 20:51:31 GMT", "version": "v1" }, { "created": "Fri, 7 Mar 2008 16:28:48 GMT", "version": "v2" }, { "created": "Tue, 17 Jun 2008 08:02:01 GMT", "version": "v3" } ]
2010-02-03
[ [ "Coloma", "Pilar", "" ], [ "Donini", "Andrea", "" ], [ "Fernandez-Martinez", "Enrique", "" ], [ "Lopez-Pavon", "Jacobo", "" ] ]
We consider a $\beta$-Beam facility where $^8$Li and $^8$B ions are accelerated at $\gamma = 350$, accumulated in a 10 Km storage ring and let decay, so as to produce intense $\bar \nu_e$ and $\nu_e$ beams. These beams illuminate two iron detectors located at $L \simeq 2000$ Km and $L \simeq 7000$ Km, respectively. The physics potential of this setup is analysed in full detail as a function of the flux. We find that, for the highest flux ($10 \times 10^{18}$ ion decays per year per baseline), the sensitivity to $\theta_{13}$ reaches $\sin^2 2 \theta_{13} \geq 2 \times10^{-4}$; the sign of the atmospheric mass difference can be identified, regardless of the true hierarchy, for $\sin^2 2 \theta_{13} \geq 4\times10^{-4}$; and, CP-violation can be discovered in 70% of the $\delta$-parameter space for $\sin^2 2 \theta_{13} \geq 10^{-3}$, having some sensitivity to CP-violation down to $\sin^2 2 \theta_{13} \geq 10^{-4}$ for $|\delta| \sim 90^\circ$.
2111.03872
Shilpa Jangid
Priyotosh Bandyopadhyay, Shilpa Jangid, Anirban Karan
Constraining Scalar Doublet and Triplet Leptoquarks with Vacuum Stability and Perturbativity
45 pages, 56 figures, 2 tables
Eur. Phys. J. C 82, 516 (2022)
10.1140/epjc/s10052-022-10418-6
IITH-PH-0004/21
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the constraints on the leptoquark Yukawa couplings and Higgs-leptoquark quartic couplings for scalar doublet leptoquark $\tilde{R}_2$, scalar triplet leptoquark $\vec S_3$ and their combination with both three generations and one generation from perturbative unitarity and vacuum stability. Perturbative unitarity of all the dimensionless couplings have been studied via one- and two-loop beta-functions. Introduction of new $SU(2)$ multiplets in terms of these leptoquarks fabricate Landau poles at two-loop level in the gauge coupling $g_2$ at $10^{19.7}$ GeV and $10^{14.4}$ GeV, respectively for $\vec S_3$ and $\tilde{R}_2+\vec S_3$ models with three generations. However, such Landau pole ceases to exist for $\tilde{R}_2$ and any of these extensions with both one and two generations till Planck scale. The Higgs-leptoquark quartic couplings acquire severe constraints to protect Planck scale perturbativity, whereas leptoquark Yukawa couplings get some upper bound in order to respect Planck scale stability of Higgs Vacuum. The Higgs quartic coupling at two-loop constraints the leptoquark Yukawa couplings for $\tilde{R}_2,\vec S_3, \,\tilde{R}_2+\vec S_3$ with values $\lesssim 1.30, 3.90, 1.00$ with three generations. In the effective potential approach, the presence of any of these leptoquarks with any number of generations pushes the metastable vacuum of the Standard Model to the stable region.
[ { "created": "Sat, 6 Nov 2021 12:37:55 GMT", "version": "v1" }, { "created": "Thu, 9 Jun 2022 09:14:07 GMT", "version": "v2" } ]
2022-06-10
[ [ "Bandyopadhyay", "Priyotosh", "" ], [ "Jangid", "Shilpa", "" ], [ "Karan", "Anirban", "" ] ]
We investigate the constraints on the leptoquark Yukawa couplings and Higgs-leptoquark quartic couplings for scalar doublet leptoquark $\tilde{R}_2$, scalar triplet leptoquark $\vec S_3$ and their combination with both three generations and one generation from perturbative unitarity and vacuum stability. Perturbative unitarity of all the dimensionless couplings have been studied via one- and two-loop beta-functions. Introduction of new $SU(2)$ multiplets in terms of these leptoquarks fabricate Landau poles at two-loop level in the gauge coupling $g_2$ at $10^{19.7}$ GeV and $10^{14.4}$ GeV, respectively for $\vec S_3$ and $\tilde{R}_2+\vec S_3$ models with three generations. However, such Landau pole ceases to exist for $\tilde{R}_2$ and any of these extensions with both one and two generations till Planck scale. The Higgs-leptoquark quartic couplings acquire severe constraints to protect Planck scale perturbativity, whereas leptoquark Yukawa couplings get some upper bound in order to respect Planck scale stability of Higgs Vacuum. The Higgs quartic coupling at two-loop constraints the leptoquark Yukawa couplings for $\tilde{R}_2,\vec S_3, \,\tilde{R}_2+\vec S_3$ with values $\lesssim 1.30, 3.90, 1.00$ with three generations. In the effective potential approach, the presence of any of these leptoquarks with any number of generations pushes the metastable vacuum of the Standard Model to the stable region.
1411.0664
Doojin Kim
Won Sang Cho, James S. Gainer, Doojin Kim, Konstantin T. Matchev, Filip Moortgat, Luc Pape, Myeonghun Park
Improving the sensitivity of stop searches with on-shell constrained invariant mass variables
49 pages, 28 figures, revised version published in JHEP, references added
JHEP 1505 (2015) 040
10.1007/JHEP05(2015)040
CTPU-14-11, APCTP Pre2014 - 014, IPMU14-0333
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The search for light stops is of paramount importance, both in general as a promising path to the discovery of beyond the standard model physics and more specifically as a way of evaluating the success of the naturalness paradigm. While the LHC experiments have ruled out much of the relevant parameter space, there are "stop gaps", i.e., values of sparticle masses for which existing LHC analyses have relatively little sensitivity to light stops. We point out that techniques involving on-shell constrained M_2 variables can do much to enhance sensitivity in this region and hence help close the stop gaps. We demonstrate the use of these variables for several benchmark points and describe the effect of realistic complications, such as detector effects and combinatorial backgrounds, in order to provide a useful toolkit for light stop searches in particular, and new physics searches at the LHC in general.
[ { "created": "Mon, 3 Nov 2014 21:00:00 GMT", "version": "v1" }, { "created": "Thu, 17 Sep 2015 02:11:13 GMT", "version": "v2" } ]
2015-09-18
[ [ "Cho", "Won Sang", "" ], [ "Gainer", "James S.", "" ], [ "Kim", "Doojin", "" ], [ "Matchev", "Konstantin T.", "" ], [ "Moortgat", "Filip", "" ], [ "Pape", "Luc", "" ], [ "Park", "Myeonghun", "" ] ]
The search for light stops is of paramount importance, both in general as a promising path to the discovery of beyond the standard model physics and more specifically as a way of evaluating the success of the naturalness paradigm. While the LHC experiments have ruled out much of the relevant parameter space, there are "stop gaps", i.e., values of sparticle masses for which existing LHC analyses have relatively little sensitivity to light stops. We point out that techniques involving on-shell constrained M_2 variables can do much to enhance sensitivity in this region and hence help close the stop gaps. We demonstrate the use of these variables for several benchmark points and describe the effect of realistic complications, such as detector effects and combinatorial backgrounds, in order to provide a useful toolkit for light stop searches in particular, and new physics searches at the LHC in general.
hep-ph/0307091
Iain Peddie
Steve F. King and Iain N. R. Peddie
Lepton Flavour Violation from Yukawa Operators, Supergravity and the See-Saw mechanism
35 pages, 3 figures; Additional references
Nucl.Phys. B678 (2004) 339-362
10.1016/j.nuclphysb.2003.10.051
SHEP:0320
hep-ph
null
We investigate the phenomenological impact of different sources of lepton flavour violation arising from realistic models based on supergravity mediated supersymmetry breaking with Yukawa operators. We discuss four distinct sources of lepton flavour violation in such models: minimum flavour violation, arising from neutrino masses and the see-saw mechanism with RG running; supergravity flavour violation due to the non-universal structure of the supergravity model; flavour violation due to Froggatt-Nielsen (FN) fields appearing in Yukawa operators developing supersymmetry breaking F-terms and contributing in a non-universal way to soft trilinear terms; and finally heavy Higgs flavour violation arising from the heavy Higgs fields used to break the unified gauge symmetry which also appear in Yukawa operators and behave analagously to the FN fields. In order to quantify the relative effects, we study a particular type I string inspired model based on a supersymmetric Pati-Salam model arising from intersecting D-branes, supplemented by a U(1) family symmetry
[ { "created": "Mon, 7 Jul 2003 16:17:23 GMT", "version": "v1" }, { "created": "Tue, 22 Jul 2003 15:18:53 GMT", "version": "v2" } ]
2010-04-05
[ [ "King", "Steve F.", "" ], [ "Peddie", "Iain N. R.", "" ] ]
We investigate the phenomenological impact of different sources of lepton flavour violation arising from realistic models based on supergravity mediated supersymmetry breaking with Yukawa operators. We discuss four distinct sources of lepton flavour violation in such models: minimum flavour violation, arising from neutrino masses and the see-saw mechanism with RG running; supergravity flavour violation due to the non-universal structure of the supergravity model; flavour violation due to Froggatt-Nielsen (FN) fields appearing in Yukawa operators developing supersymmetry breaking F-terms and contributing in a non-universal way to soft trilinear terms; and finally heavy Higgs flavour violation arising from the heavy Higgs fields used to break the unified gauge symmetry which also appear in Yukawa operators and behave analagously to the FN fields. In order to quantify the relative effects, we study a particular type I string inspired model based on a supersymmetric Pati-Salam model arising from intersecting D-branes, supplemented by a U(1) family symmetry
hep-ph/0005308
Konstantin Matchev
Bogdan A. Dobrescu (Fermilab), Greg Landsberg (Brown U) and Konstantin T. Matchev (Fermilab)
Higgs Boson Decays to CP-odd Scalars at the Tevatron and Beyond
4 pages, 3 figures
Phys.Rev.D63:075003,2001
10.1103/PhysRevD.63.075003
FERMILAB-PUB-99/324-T
hep-ph hep-ex
null
In extended Higgs models, the Higgs boson may decay into a pair of light CP-odd scalars, with distinctive collider signatures. We study the ensuing Higgs signals at the upgraded Tevatron, considering the subsequent decays of the scalars into pairs of gluons or photons. For CP-odd scalars lighter than a few GeV, the Higgs boson manifests itself as a diphoton resonance and can be discovered up to masses of a few hundred GeV. For heavier CP-odd scalars the reach extends at most up to $M_h\sim 120$ GeV. We also discuss the capabilities of the LHC and lepton colliders in these channels.
[ { "created": "Wed, 31 May 2000 20:45:29 GMT", "version": "v1" } ]
2008-11-26
[ [ "Dobrescu", "Bogdan A.", "", "Fermilab" ], [ "Landsberg", "Greg", "", "Brown U" ], [ "Matchev", "Konstantin T.", "", "Fermilab" ] ]
In extended Higgs models, the Higgs boson may decay into a pair of light CP-odd scalars, with distinctive collider signatures. We study the ensuing Higgs signals at the upgraded Tevatron, considering the subsequent decays of the scalars into pairs of gluons or photons. For CP-odd scalars lighter than a few GeV, the Higgs boson manifests itself as a diphoton resonance and can be discovered up to masses of a few hundred GeV. For heavier CP-odd scalars the reach extends at most up to $M_h\sim 120$ GeV. We also discuss the capabilities of the LHC and lepton colliders in these channels.
hep-ph/9406287
Chen Yu-qi
Yu-Qi Chen, Yu-Ping Kuang and Robert J. Oakes
On The Spin-Dependent Potential Between Heavy Quark And Antiquark
12 pages, REVTEX; NSF-ITP-94-49, TUIMP-TH-94/59, NUHEP-TH-94-10
Phys.Rev.D52:264-270,1995
10.1103/PhysRevD.52.264
null
hep-ph
null
A new formula for the heavy quark-antiquark spin dependent potential is given by using the techniques developed in the heavy quark effective theory. The leading logarithmic quark mass terms emerging from the loop contributions are explicitly extracted and summed up. There is no renormalization scale ambiguity in this new formula. The spin-dependent potential in the new formula is expressed in terms of three independent color-electric and color-magnetic field correlation functions, and it includes both the Eichten-Feinberg's formula and the one-loop QCD result as special cases.
[ { "created": "Sat, 11 Jun 1994 17:18:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Chen", "Yu-Qi", "" ], [ "Kuang", "Yu-Ping", "" ], [ "Oakes", "Robert J.", "" ] ]
A new formula for the heavy quark-antiquark spin dependent potential is given by using the techniques developed in the heavy quark effective theory. The leading logarithmic quark mass terms emerging from the loop contributions are explicitly extracted and summed up. There is no renormalization scale ambiguity in this new formula. The spin-dependent potential in the new formula is expressed in terms of three independent color-electric and color-magnetic field correlation functions, and it includes both the Eichten-Feinberg's formula and the one-loop QCD result as special cases.
2306.00682
Xun Chen
Xun Chen, Bo Yu, Peng-Cheng Chu, Xiao-Hua Li
The effect of gluon condensate on the entanglement entropy in a holographic model
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effect of gluon condensate on the holographic entanglement entropy is investigated in an Einstein-Dilaton model at zero and finite temperature. There is a critical length for the difference of entanglement entropy between the connected and disconnected surfaces in this model, which is often regarded as a signal of phase transition. With the increase of gluon condensate, the critical length becomes small, which means the confinement becomes strong at zero temperature. At finite temperatures, results show that the effect of gluon condensate on the critical length is qualitatively consistent with the case of zero temperature. However, the temperature will slightly increase the critical length for a fixed gluon condensate, which indicates the temperature will contribute to the deconfinement of the system.
[ { "created": "Thu, 1 Jun 2023 13:55:44 GMT", "version": "v1" }, { "created": "Tue, 24 Oct 2023 07:33:16 GMT", "version": "v2" }, { "created": "Tue, 30 Jan 2024 08:48:34 GMT", "version": "v3" } ]
2024-01-31
[ [ "Chen", "Xun", "" ], [ "Yu", "Bo", "" ], [ "Chu", "Peng-Cheng", "" ], [ "Li", "Xiao-Hua", "" ] ]
The effect of gluon condensate on the holographic entanglement entropy is investigated in an Einstein-Dilaton model at zero and finite temperature. There is a critical length for the difference of entanglement entropy between the connected and disconnected surfaces in this model, which is often regarded as a signal of phase transition. With the increase of gluon condensate, the critical length becomes small, which means the confinement becomes strong at zero temperature. At finite temperatures, results show that the effect of gluon condensate on the critical length is qualitatively consistent with the case of zero temperature. However, the temperature will slightly increase the critical length for a fixed gluon condensate, which indicates the temperature will contribute to the deconfinement of the system.
hep-ph/0110105
Takahashi Keitaro
K.Takahashi and K.Sato
Earth effects on supernova neutrinos and their implications for neutrino parameters
20 pages, 14 figures, added some discussions
Phys.Rev. D66 (2002) 033006
10.1103/PhysRevD.66.033006
UTAP-403/01,RESCEU-22/01
hep-ph astro-ph
null
We perform a detailed study of the Earth matter effects on supernova neutrinos with neutrino oscillation parameter LMA and small $\theta_{13}$. The Earth effects show significant dependences on the neutrino path length inside the Earth and the value of $\Delta m^{2}_{12}$. We investigate rather optimistically a possibility that we can probe the value of $\Delta m^{2}_{12}$ by the Earth effects. We assume that $\theta_{12}$ and the direction of the supernova are known with enough accuracy and that the resonance that occurs at higher density in supernova envelope is completely nonadiabatic. Further the neutrino spectra before neutrinos go through the Earth are assumed to be known. Then we show that making use of these dependences, we can obtain implication for the value of $\Delta m^{2}_{12}$ by comparing the observed energy spectrum to the predicted one. When SK detects neutrinos from supernova at 10kpc which traveled through the Earth (nadir angle $<$ 80 degree), $\Delta m^{2}_{12}$ can be determined with an accuracy of $\sim 10%$. In much of the neutrino-detection-time-$\Delta m^{2}_{12}$ plane, $\Delta m^{2}_{12}$ might be determined with an accuracy equal to or better than $\pm 0.5 \times 10^{-5} {\rm eV}^{2}$.
[ { "created": "Mon, 8 Oct 2001 10:48:47 GMT", "version": "v1" }, { "created": "Sat, 23 Mar 2002 03:20:26 GMT", "version": "v2" } ]
2009-11-07
[ [ "Takahashi", "K.", "" ], [ "Sato", "K.", "" ] ]
We perform a detailed study of the Earth matter effects on supernova neutrinos with neutrino oscillation parameter LMA and small $\theta_{13}$. The Earth effects show significant dependences on the neutrino path length inside the Earth and the value of $\Delta m^{2}_{12}$. We investigate rather optimistically a possibility that we can probe the value of $\Delta m^{2}_{12}$ by the Earth effects. We assume that $\theta_{12}$ and the direction of the supernova are known with enough accuracy and that the resonance that occurs at higher density in supernova envelope is completely nonadiabatic. Further the neutrino spectra before neutrinos go through the Earth are assumed to be known. Then we show that making use of these dependences, we can obtain implication for the value of $\Delta m^{2}_{12}$ by comparing the observed energy spectrum to the predicted one. When SK detects neutrinos from supernova at 10kpc which traveled through the Earth (nadir angle $<$ 80 degree), $\Delta m^{2}_{12}$ can be determined with an accuracy of $\sim 10%$. In much of the neutrino-detection-time-$\Delta m^{2}_{12}$ plane, $\Delta m^{2}_{12}$ might be determined with an accuracy equal to or better than $\pm 0.5 \times 10^{-5} {\rm eV}^{2}$.
0710.1212
Alexei Nefediev
A.V.Nefediev (ITEP, Moscow)
The nature of the light scalar mesons from their radiative decays
Invited talk at the International Symposium on Meson-Nucleon Physics and the Structure of Hadrons (MENU2007), September 10-14, 2007, Forschungszentrum Juelich, Germany; LaTeX, 4 pages, uses conference.cls, to appear in Proceedings
ECONFC070910:155,2007
null
null
hep-ph
null
The nature of the light scalar mesons is one of the most intriguing open challenges in hadronic spectroscopy. It is argued that radiative decays involving these scalars can serve as an important decisive tool in establishing their nature. In particular, special emphasis is made on the radiative decays of the scalars themselves (in addition to the radiative decays of the phi-meson with the scalars appearing in the final state), including their two-photon decays. All the above mentioned processes are considered in detail in the (point-like) kaon molecule model of the scalars and explicit predictions for the decay widths are made. In addition, finite-range corrections to the point-like results are investigated, with a special attention payed to gauge invariance of the decay amplitude. Finally, the conclusion is made that experimental data on the radiative decays with the light scalar mesons involved strongly support the molecule assignment for the latter.
[ { "created": "Fri, 5 Oct 2007 12:49:29 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nefediev", "A. V.", "", "ITEP, Moscow" ] ]
The nature of the light scalar mesons is one of the most intriguing open challenges in hadronic spectroscopy. It is argued that radiative decays involving these scalars can serve as an important decisive tool in establishing their nature. In particular, special emphasis is made on the radiative decays of the scalars themselves (in addition to the radiative decays of the phi-meson with the scalars appearing in the final state), including their two-photon decays. All the above mentioned processes are considered in detail in the (point-like) kaon molecule model of the scalars and explicit predictions for the decay widths are made. In addition, finite-range corrections to the point-like results are investigated, with a special attention payed to gauge invariance of the decay amplitude. Finally, the conclusion is made that experimental data on the radiative decays with the light scalar mesons involved strongly support the molecule assignment for the latter.
1304.3552
Alfredo Valcarce
H. Garcilazo, A. Valcarce
Reply to "Comment on Strangeness -2 hypertriton"
1 page. Exact version accepted for publication in Physical Review Letters
Phys. Rev. Lett 110, 179202 (2013)
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this Reply we argue that the conclusions derived in Ref. arXiv:1301.1241 are questionable.
[ { "created": "Fri, 12 Apr 2013 06:50:54 GMT", "version": "v1" } ]
2013-05-01
[ [ "Garcilazo", "H.", "" ], [ "Valcarce", "A.", "" ] ]
In this Reply we argue that the conclusions derived in Ref. arXiv:1301.1241 are questionable.
2301.09645
Keith Hamilton
Keith Hamilton, Alexander Karlberg, Gavin P. Salam, Ludovic Scyboz, Rob Verheyen
Matching and event-shape NNDL accuracy in parton showers
42 pages, 14 figures; v2: matches published version; v3: corrected typos in eqs. 1.1, 4.1, A.4, no other content affected
null
10.1007/JHEP03(2023)224
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
To explore the interplay of NLO matching and next-to-leading logarithmic (NLL) parton showers, we consider the simplest case of $\gamma^*$ and Higgs-boson decays to $q\bar q$ and $gg$ respectively. Not only should shower NLL accuracy be retained across observables after matching, but for global event-shape observables and the two-jet rate, matching can augment the shower in such a way that it additionally achieves next-to-next-to-double-logarithmic (NNDL) accuracy, a first step on the route towards general NNLL. As a proof-of-concept exploration of this question, we consider direct application of multiplicative matrix-element corrections, as well as simple implementations of MC@NLO and POWHEG-style matching. We find that the first two straightforwardly bring NNDL accuracy, and that this can also be achieved with POWHEG, although particular care is needed in the handover between POWHEG and the shower. Our study involves both analytic and numerical components and we also touch on some phenomenological considerations.
[ { "created": "Mon, 23 Jan 2023 19:00:00 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2023 09:19:19 GMT", "version": "v2" }, { "created": "Mon, 23 Oct 2023 19:40:05 GMT", "version": "v3" } ]
2023-10-25
[ [ "Hamilton", "Keith", "" ], [ "Karlberg", "Alexander", "" ], [ "Salam", "Gavin P.", "" ], [ "Scyboz", "Ludovic", "" ], [ "Verheyen", "Rob", "" ] ]
To explore the interplay of NLO matching and next-to-leading logarithmic (NLL) parton showers, we consider the simplest case of $\gamma^*$ and Higgs-boson decays to $q\bar q$ and $gg$ respectively. Not only should shower NLL accuracy be retained across observables after matching, but for global event-shape observables and the two-jet rate, matching can augment the shower in such a way that it additionally achieves next-to-next-to-double-logarithmic (NNDL) accuracy, a first step on the route towards general NNLL. As a proof-of-concept exploration of this question, we consider direct application of multiplicative matrix-element corrections, as well as simple implementations of MC@NLO and POWHEG-style matching. We find that the first two straightforwardly bring NNDL accuracy, and that this can also be achieved with POWHEG, although particular care is needed in the handover between POWHEG and the shower. Our study involves both analytic and numerical components and we also touch on some phenomenological considerations.
2002.00267
Harald Fritzsch
Harald Fritzsch
Oscillating Neutrinos and Majorana Neutrino Masses
9 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The texture zero mass matrices for the leptons and the seesaw mechanism are used to derive relations between the matrix elements of the lepton mixing matrix and the ratios of the neutrino masses.
[ { "created": "Sat, 1 Feb 2020 20:00:38 GMT", "version": "v1" } ]
2020-02-04
[ [ "Fritzsch", "Harald", "" ] ]
The texture zero mass matrices for the leptons and the seesaw mechanism are used to derive relations between the matrix elements of the lepton mixing matrix and the ratios of the neutrino masses.
2309.06524
Osvaldo Ferreira MSc
Osvaldo Ferreira and Eduardo S. Fraga
Power corrections to the photon polarization tensor in a hot and dense medium of massive fermions
10 pages, 2 figure. Additional section included in this version. Matches the published version
null
10.1103/PhysRevD.109.016025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the $\mathcal{O}(k^2)$ terms (power corrections) of the photon polarization tensor in a hot and dense medium of particles with a small but finite mass, i.e., $0< m\ll T, \mu$. We perform our calculations within the hard thermal loop approximation in the real-time formalism, and evaluate the first nonzero mass corrections. For a renormalization scale $\bar{\Lambda}\sim T$, these mass contributions determine the temperature dependence of the power corrections. These results have direct implications in the computation of electric and magnetic susceptibilities of hot and dense media in equilibrium. We address such implications and make comparisons with previous results.
[ { "created": "Tue, 12 Sep 2023 18:59:02 GMT", "version": "v1" }, { "created": "Wed, 24 Jan 2024 00:47:47 GMT", "version": "v2" } ]
2024-01-25
[ [ "Ferreira", "Osvaldo", "" ], [ "Fraga", "Eduardo S.", "" ] ]
We compute the $\mathcal{O}(k^2)$ terms (power corrections) of the photon polarization tensor in a hot and dense medium of particles with a small but finite mass, i.e., $0< m\ll T, \mu$. We perform our calculations within the hard thermal loop approximation in the real-time formalism, and evaluate the first nonzero mass corrections. For a renormalization scale $\bar{\Lambda}\sim T$, these mass contributions determine the temperature dependence of the power corrections. These results have direct implications in the computation of electric and magnetic susceptibilities of hot and dense media in equilibrium. We address such implications and make comparisons with previous results.
0901.0986
Edmond Iancu
Edmond Iancu
Color Glass Condensate and its relation to HERA physics
14 pages, 8 figures. Invited talk at the Ringberg Workshop New Trends in HERA Physics 2008, October 5-10 2008, Ringberg Castle, Tegernsee, Germany
null
10.1016/j.nuclphysbps.2009.03.135
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I give a brief overview of the effective theory for the Color Glass Condensate, which is the high-density gluonic matter which controls high-energy scattering in QCD in the vicinity of the unitarity limit. I concentrate on fundamental phenomena, like gluon saturation, unitarization, and geometric scaling, and the way how these are encoded in the formalism. I emphasize the importance of the next-to-leading order corrections, especially the running of the coupling, for both conceptual and phenomenological issues. I survey the implications of the CGC theory for the HERA physics and its phenomenological applications based on saturation models.
[ { "created": "Thu, 8 Jan 2009 08:47:48 GMT", "version": "v1" } ]
2015-05-13
[ [ "Iancu", "Edmond", "" ] ]
I give a brief overview of the effective theory for the Color Glass Condensate, which is the high-density gluonic matter which controls high-energy scattering in QCD in the vicinity of the unitarity limit. I concentrate on fundamental phenomena, like gluon saturation, unitarization, and geometric scaling, and the way how these are encoded in the formalism. I emphasize the importance of the next-to-leading order corrections, especially the running of the coupling, for both conceptual and phenomenological issues. I survey the implications of the CGC theory for the HERA physics and its phenomenological applications based on saturation models.
2303.15996
Dmitry Salnikov
Dmitry Salnikov, Petr Satunin, D. V. Kirpichnikov and Maxim Fitkevich
Light-shining-through-wall cavity setups for probing ALPs
9 pages, 6 figures, 1 table. Revised version, accepted to JETP Letters
null
10.1134/S0021364023600957
INR-TH-2023-004
hep-ph
http://creativecommons.org/licenses/by/4.0/
We discuss the aspects of axion-like-particles (ALPs) searches with Light-Shining-through-Wall (LSW) experimental setups consisted of two radio-frequency cavities. We compare the efficiencies of three setups which involve the cavity pump modes and external magnetic fields. Additionally, we discuss the sensitivity dependence both on the relative position of two cylindrical cavities and on their radius-to-length ratio.
[ { "created": "Tue, 28 Mar 2023 14:10:30 GMT", "version": "v1" }, { "created": "Thu, 30 Mar 2023 14:49:09 GMT", "version": "v2" }, { "created": "Fri, 12 May 2023 08:50:58 GMT", "version": "v3" } ]
2023-06-28
[ [ "Salnikov", "Dmitry", "" ], [ "Satunin", "Petr", "" ], [ "Kirpichnikov", "D. V.", "" ], [ "Fitkevich", "Maxim", "" ] ]
We discuss the aspects of axion-like-particles (ALPs) searches with Light-Shining-through-Wall (LSW) experimental setups consisted of two radio-frequency cavities. We compare the efficiencies of three setups which involve the cavity pump modes and external magnetic fields. Additionally, we discuss the sensitivity dependence both on the relative position of two cylindrical cavities and on their radius-to-length ratio.
0810.1301
Steve Blanchet
Steve Blanchet and Pavel Fileviez Perez
On the Role of Low-Energy CP Violation in Leptogenesis
12 pages, 6 figures
Mod.Phys.Lett.A24:1399-1409,2009
10.1142/S0217732309030862
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The link between low-energy CP violation and leptogenesis became more accessible with the understanding of flavor effects. However, a definite well-motivated model where such a link occurs was still lacking. Adjoint SU(5) is a simple grand unified theory where neutrino masses are generated through the Type I and Type III seesaw mechanisms, and the lepton asymmetry is generated by the fermionic triplet responsible for the Type III seesaw. We focus exclusively on the case of inverted hierarchy for neutrinos, and we show that successful flavored leptogenesis in this theory strongly points towards low-energy CP violation. Moreover, since the range of allowed masses for the triplet is very restricted, we find that the discovery at the LHC of new states present in the theory, together with proton decay and unification of gauge couplings, can conspire to provide a hint in favor of leptogenesis.
[ { "created": "Wed, 8 Oct 2008 17:59:26 GMT", "version": "v1" } ]
2014-11-18
[ [ "Blanchet", "Steve", "" ], [ "Perez", "Pavel Fileviez", "" ] ]
The link between low-energy CP violation and leptogenesis became more accessible with the understanding of flavor effects. However, a definite well-motivated model where such a link occurs was still lacking. Adjoint SU(5) is a simple grand unified theory where neutrino masses are generated through the Type I and Type III seesaw mechanisms, and the lepton asymmetry is generated by the fermionic triplet responsible for the Type III seesaw. We focus exclusively on the case of inverted hierarchy for neutrinos, and we show that successful flavored leptogenesis in this theory strongly points towards low-energy CP violation. Moreover, since the range of allowed masses for the triplet is very restricted, we find that the discovery at the LHC of new states present in the theory, together with proton decay and unification of gauge couplings, can conspire to provide a hint in favor of leptogenesis.
hep-ph/9704398
Frank Klingl
F. Klingl, N. Kaiser and W. Weise
Current correlation functions, QCD sum rules and vector mesons in baryonic matter
40 pages, LaTeX 2e,10 figures in eps , submitted to Nucl.Phys.A
Nucl.Phys.A624:527-563,1997
10.1016/S0375-9474(97)88960-9
null
hep-ph nucl-th
null
Based on an effective Lagrangian which combines chiral SU(3) dynamics with vector meson dominance, we have developed a model for the forward vector meson-nucleon scattering amplitudes. We use this as an input to calculate the low energy part of the current-current correlation function in nuclear matter. Its spectrum enters directly in the ``left hand side'' of QCD sum rules. For the isovector channel we find a significant enhancement of the in-medium spectral density below the rho resonance while the rho meson mass itself changes only slightly. The situation is different in the isoscalar channel, where the mass and peak position of the omega meson move downward while its width increases less drastically than in the rho meson case. For the phi meson we find almost no mass shift; the width of the peak broadens moderately. We observe a remarkable degree of consistency with the operator product expansion of QCD sum rules in all three channels. We point out, however, that these results cannot simply be interpreted, as commonly done, in terms of a universal rescaling of vector meson masses in matter.
[ { "created": "Thu, 24 Apr 1997 14:08:51 GMT", "version": "v1" } ]
2009-07-09
[ [ "Klingl", "F.", "" ], [ "Kaiser", "N.", "" ], [ "Weise", "W.", "" ] ]
Based on an effective Lagrangian which combines chiral SU(3) dynamics with vector meson dominance, we have developed a model for the forward vector meson-nucleon scattering amplitudes. We use this as an input to calculate the low energy part of the current-current correlation function in nuclear matter. Its spectrum enters directly in the ``left hand side'' of QCD sum rules. For the isovector channel we find a significant enhancement of the in-medium spectral density below the rho resonance while the rho meson mass itself changes only slightly. The situation is different in the isoscalar channel, where the mass and peak position of the omega meson move downward while its width increases less drastically than in the rho meson case. For the phi meson we find almost no mass shift; the width of the peak broadens moderately. We observe a remarkable degree of consistency with the operator product expansion of QCD sum rules in all three channels. We point out, however, that these results cannot simply be interpreted, as commonly done, in terms of a universal rescaling of vector meson masses in matter.
hep-ph/0103209
Alessandro Drago
Alessandro Drago and Andrea Lavagno
From Quark Stars to Hybrid Stars
10 pages, 4 figures, 1 table
Phys.Lett. B511 (2001) 229-234
10.1016/S0370-2693(01)00579-2
null
hep-ph astro-ph nucl-th
null
We show the possible existence of compact stars having a surface composed of a mixed phase of quarks and hadrons. This scenario can be realized both for self-bound stars, satisfying the so-called Witten-Bodmer hypothesis, and for gravitationally bound stars. This class of solutions of the Tolman-Oppenheimer-Volkoff equation can be obtained in all the models we discuss, within a physically acceptable range of values of the model parameters.
[ { "created": "Tue, 20 Mar 2001 03:31:47 GMT", "version": "v1" } ]
2009-11-07
[ [ "Drago", "Alessandro", "" ], [ "Lavagno", "Andrea", "" ] ]
We show the possible existence of compact stars having a surface composed of a mixed phase of quarks and hadrons. This scenario can be realized both for self-bound stars, satisfying the so-called Witten-Bodmer hypothesis, and for gravitationally bound stars. This class of solutions of the Tolman-Oppenheimer-Volkoff equation can be obtained in all the models we discuss, within a physically acceptable range of values of the model parameters.
1201.6300
Ulrich Jentschura
U. D. Jentschura
Dirac Hamiltonian with Imaginary Mass and Induced Helicity-Dependence by Indefinite Metric
8 pages; RevTeX; published in J.Mod.Phys
J.Mod.Phys. 3 (2012) 887-894
10.4236/jmp.2012.39116
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is of general theoretical interest to investigate the properties of superluminal matter wave equations for spin one-half particles. One can either enforce superluminal propagation by an explicit substitution of the real mass term for an imaginary mass, or one can use a matrix representation of the imaginary unit that multiplies the mass term. The latter leads to the tachyonic Dirac equation, while the equation obtained by the substitution m->i*m in the Dirac equation is naturally referred to as the imaginary-mass Dirac equation. Both the tachyonic as well as the imaginary-mass Dirac Hamiltonians commute with the helicity operator. Both Hamiltonians are pseudo-Hermitian and also possess additional modified pseudo-Hermitian properties, leading to constraints on the resonance eigenvalues. Here, by an explicit calculation, we show that specific sum rules over the spectrum hold for the wave functions corresponding to the well-defined real energy eigenvalues and complex resonance and anti-resonance energies. In the quantized imaginary-mass Dirac field, one-particle states of right-handed helicity acquire a negative norm ("indefinite metric") and can be excluded from the physical spectrum by a Gupta--Bleuler type condition.
[ { "created": "Mon, 30 Jan 2012 17:43:46 GMT", "version": "v1" }, { "created": "Mon, 16 Apr 2012 14:58:07 GMT", "version": "v2" }, { "created": "Thu, 5 Jul 2012 15:14:48 GMT", "version": "v3" }, { "created": "Wed, 3 Oct 2012 11:23:36 GMT", "version": "v4" } ]
2012-10-04
[ [ "Jentschura", "U. D.", "" ] ]
It is of general theoretical interest to investigate the properties of superluminal matter wave equations for spin one-half particles. One can either enforce superluminal propagation by an explicit substitution of the real mass term for an imaginary mass, or one can use a matrix representation of the imaginary unit that multiplies the mass term. The latter leads to the tachyonic Dirac equation, while the equation obtained by the substitution m->i*m in the Dirac equation is naturally referred to as the imaginary-mass Dirac equation. Both the tachyonic as well as the imaginary-mass Dirac Hamiltonians commute with the helicity operator. Both Hamiltonians are pseudo-Hermitian and also possess additional modified pseudo-Hermitian properties, leading to constraints on the resonance eigenvalues. Here, by an explicit calculation, we show that specific sum rules over the spectrum hold for the wave functions corresponding to the well-defined real energy eigenvalues and complex resonance and anti-resonance energies. In the quantized imaginary-mass Dirac field, one-particle states of right-handed helicity acquire a negative norm ("indefinite metric") and can be excluded from the physical spectrum by a Gupta--Bleuler type condition.
2103.11814
Dmitry Gorbunov
Dmitry Gorbunov, Igor Krasnov, Yury Kudenko, Sergey Suvorov
Double-Hit Signature of Millicharged Particles in 3D segmented neutrino detector
15 pages, 8 figures; v2: replaced with published version
null
10.1016/j.physletb.2021.136641
INR-TH-2021-006
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We calculate the production of hypothetical millicharged particles (MCPs) of sub-GeV masses by the J-PARC proton beam in the framework of T2K and future T2HK neutrino oscillation experiments. Concentrating on the region of model parameter space, where an MCP can hit the near neutrino detector twice, we adopt this background-free signature to estimate the sensitivity of T2K and T2HK experiments to MCPs. We find that a previously inaccessible in direct searches region of charges 5$\times$$10^{-4}$-$10^{-2}$ $e$ for MCP masses 0.1-0.5 GeV can be probed.
[ { "created": "Mon, 22 Mar 2021 13:13:42 GMT", "version": "v1" }, { "created": "Thu, 30 Sep 2021 11:37:47 GMT", "version": "v2" } ]
2021-10-01
[ [ "Gorbunov", "Dmitry", "" ], [ "Krasnov", "Igor", "" ], [ "Kudenko", "Yury", "" ], [ "Suvorov", "Sergey", "" ] ]
We calculate the production of hypothetical millicharged particles (MCPs) of sub-GeV masses by the J-PARC proton beam in the framework of T2K and future T2HK neutrino oscillation experiments. Concentrating on the region of model parameter space, where an MCP can hit the near neutrino detector twice, we adopt this background-free signature to estimate the sensitivity of T2K and T2HK experiments to MCPs. We find that a previously inaccessible in direct searches region of charges 5$\times$$10^{-4}$-$10^{-2}$ $e$ for MCP masses 0.1-0.5 GeV can be probed.
1707.09130
Kazuya Mameda
Hao-Lei Chen, Kenji Fukushima, Xu-Guang Huang, and Kazuya Mameda
Surface Magnetic Catalysis
11 pages, 4 figures
Phys. Rev. D 96, 054032 (2017)
10.1103/PhysRevD.96.054032
null
hep-ph cond-mat.mes-hall hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study fermions in a magnetic field in a finite size cylinder. With the boundary condition for the fermion flux, we show that the energy spectra and the wave-functions are modified by the finite size effect; the boundary makes the degenerate Landau levels appear only partially for states with small angular momenta, while the boundary effect becomes stronger for states with large angular momenta. We find that mode accumulation at the boundary occurs for large angular momenta and the magnetic effect is enhanced on the boundary surface. Using a simple fermionic model, we quantify the magnetic catalysis, i.e. the magnetic enhancement of the fermion pair condensation, in a finite size cylinder. We confirm that the magnetic catalysis is strongly amplified at the boundary due to the mode accumulation.
[ { "created": "Fri, 28 Jul 2017 07:34:27 GMT", "version": "v1" }, { "created": "Sat, 30 Sep 2017 03:08:08 GMT", "version": "v2" } ]
2017-10-04
[ [ "Chen", "Hao-Lei", "" ], [ "Fukushima", "Kenji", "" ], [ "Huang", "Xu-Guang", "" ], [ "Mameda", "Kazuya", "" ] ]
We study fermions in a magnetic field in a finite size cylinder. With the boundary condition for the fermion flux, we show that the energy spectra and the wave-functions are modified by the finite size effect; the boundary makes the degenerate Landau levels appear only partially for states with small angular momenta, while the boundary effect becomes stronger for states with large angular momenta. We find that mode accumulation at the boundary occurs for large angular momenta and the magnetic effect is enhanced on the boundary surface. Using a simple fermionic model, we quantify the magnetic catalysis, i.e. the magnetic enhancement of the fermion pair condensation, in a finite size cylinder. We confirm that the magnetic catalysis is strongly amplified at the boundary due to the mode accumulation.
2205.06041
Danny van Dyk
Thomas Blake, Stefan Meinel, Muslem Rahimi, Danny van Dyk
Dispersive bounds for local form factors in $\Lambda_b \to \Lambda$ transitions
20 pages, 4 figures
Phys. Rev. D 108, 094509 (2023)
10.1103/PhysRevD.108.094509
EOS-2022-01, P3H-22-046, SI-HEP-2022-09, TUM-HEP 1399/22
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the ten independent local form-factors relevant to the $b$-baryon decay $\Lambda_b \to \Lambda \ell^+\ell^-$, combining information of lattice QCD and dispersive bounds. We propose a novel parametrization of the form factors in terms of orthonormal polynomials that diagonalizes the form factor contributions to the dispersive bounds. This is a generalization of the unitarity bounds developed for meson-to-meson form-factors. In contrast to ad-hoc parametrizations of these form factors, our parametrization provides a degree of control of the form-factor uncertainties at large hadronic recoil. This is of phenomenological interest for theoretical predictions of, e.g., $\Lambda_b\to \Lambda \gamma$ and $\Lambda_b\to\Lambda \ell^+\ell^-$ decay processes.
[ { "created": "Thu, 12 May 2022 11:55:51 GMT", "version": "v1" }, { "created": "Tue, 31 May 2022 14:25:28 GMT", "version": "v2" }, { "created": "Wed, 22 Nov 2023 16:52:15 GMT", "version": "v3" } ]
2023-11-27
[ [ "Blake", "Thomas", "" ], [ "Meinel", "Stefan", "" ], [ "Rahimi", "Muslem", "" ], [ "van Dyk", "Danny", "" ] ]
We investigate the ten independent local form-factors relevant to the $b$-baryon decay $\Lambda_b \to \Lambda \ell^+\ell^-$, combining information of lattice QCD and dispersive bounds. We propose a novel parametrization of the form factors in terms of orthonormal polynomials that diagonalizes the form factor contributions to the dispersive bounds. This is a generalization of the unitarity bounds developed for meson-to-meson form-factors. In contrast to ad-hoc parametrizations of these form factors, our parametrization provides a degree of control of the form-factor uncertainties at large hadronic recoil. This is of phenomenological interest for theoretical predictions of, e.g., $\Lambda_b\to \Lambda \gamma$ and $\Lambda_b\to\Lambda \ell^+\ell^-$ decay processes.
1104.3737
Bo-Qiang Ma
Haitao Liu, Yujie Chi, Lijing Shao, Bo-Qiang Ma
Octet Quark Contents from SU(3) Flavor Symmetry
6 pages, 5 figures, final version for journal publication
Europhys.Lett.94:31001,2011
10.1209/0295-5075/94/31001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the parametrization of parton distribution functions (PDFs) of the proton by Soffer \textit{et al.}, we extend the valence quark contents to other octet baryons by utilizing SU(3) flavor symmetry. We find the method practically useful. Fragmentation functions (FFs) are further obtained through the phenomenological Gribov-Lipatov relation at the $x \to 1$ region. Our results are compared with different models, and these different predictions can be discriminated by upcoming experiments.
[ { "created": "Tue, 19 Apr 2011 13:03:43 GMT", "version": "v1" } ]
2011-05-23
[ [ "Liu", "Haitao", "" ], [ "Chi", "Yujie", "" ], [ "Shao", "Lijing", "" ], [ "Ma", "Bo-Qiang", "" ] ]
With the parametrization of parton distribution functions (PDFs) of the proton by Soffer \textit{et al.}, we extend the valence quark contents to other octet baryons by utilizing SU(3) flavor symmetry. We find the method practically useful. Fragmentation functions (FFs) are further obtained through the phenomenological Gribov-Lipatov relation at the $x \to 1$ region. Our results are compared with different models, and these different predictions can be discriminated by upcoming experiments.
1008.1497
Alysson Fabio Ferrari Prof.
A. F. Ferrari and A. Yu. Petrov
Lorentz violation in the linearized gravity
Presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 2010
null
10.1142/9789814327688_0053
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study some consequences of the introduction of a Lorentz-violating modification term in the linearized gravity, which leads to modified dispersion relations for gravitational waves in the vacuum. We also discuss possible mechanisms for the induction of such a term in the Lagrangian.
[ { "created": "Mon, 9 Aug 2010 13:14:46 GMT", "version": "v1" } ]
2017-08-23
[ [ "Ferrari", "A. F.", "" ], [ "Petrov", "A. Yu.", "" ] ]
We study some consequences of the introduction of a Lorentz-violating modification term in the linearized gravity, which leads to modified dispersion relations for gravitational waves in the vacuum. We also discuss possible mechanisms for the induction of such a term in the Lagrangian.
1709.02662
Davide Meloni
Davide Meloni
GUT and flavor models for neutrino masses and mixing
Added new references
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the recent years neutrino experiments have studied in detail the phenomenon of neutrino oscillations and most of the oscillation parameters have been measured with a good accuracy. However, in spite of many interesting ideas, the problem of flavor in the lepton sector remains an open issue. In this review, we discuss the state of the art of models for neutrino masses and mixings formulated in the context of flavor symmetries, with particular emphasis on the role played by grand unified gauge groups.
[ { "created": "Fri, 8 Sep 2017 11:49:49 GMT", "version": "v1" }, { "created": "Thu, 5 Oct 2017 12:36:30 GMT", "version": "v2" } ]
2017-10-06
[ [ "Meloni", "Davide", "" ] ]
In the recent years neutrino experiments have studied in detail the phenomenon of neutrino oscillations and most of the oscillation parameters have been measured with a good accuracy. However, in spite of many interesting ideas, the problem of flavor in the lepton sector remains an open issue. In this review, we discuss the state of the art of models for neutrino masses and mixings formulated in the context of flavor symmetries, with particular emphasis on the role played by grand unified gauge groups.
0904.0030
Pedro Bicudo
P. Bicudo
Gluon Excitations and Quark Chiral Symmetry in the Meson Spectrum: an Einbein Solution to the Large Degeneracy Problem of Light Mesons
2 figures, 1 table, more detailed version
Phys.Rev.D81:014011,2010
10.1103/PhysRevD.81.014011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A large approximate degeneracy of the excited hadron spectra, appears in the light meson spectra measured at LEAR, suggesting a novel principal quantum number n+j in QCD spectra. We recently showed that the large degeneracy could not be understood with state of the art confining and chiral invariant quark models, derived in a truncated Coulomb gauge. To search for a solution to this problem, here we add the gluon or string degrees of freedom. Although independently the quarks or the gluons would lead to a 2 n +j or 2 n +l spectrum, adding them may lead to the desired n+j pattern.
[ { "created": "Tue, 31 Mar 2009 23:14:21 GMT", "version": "v1" }, { "created": "Wed, 18 Nov 2009 12:24:38 GMT", "version": "v2" } ]
2010-04-06
[ [ "Bicudo", "P.", "" ] ]
A large approximate degeneracy of the excited hadron spectra, appears in the light meson spectra measured at LEAR, suggesting a novel principal quantum number n+j in QCD spectra. We recently showed that the large degeneracy could not be understood with state of the art confining and chiral invariant quark models, derived in a truncated Coulomb gauge. To search for a solution to this problem, here we add the gluon or string degrees of freedom. Although independently the quarks or the gluons would lead to a 2 n +j or 2 n +l spectrum, adding them may lead to the desired n+j pattern.
0911.3892
P. Q. Hung
P. Q. Hung and Chi Xiong
Implication of a Quasi Fixed Point with a Heavy Fourth Generation: The emergence of a TeV-scale physical cutoff
6 pages, 4 figures. Title changed, modified abstract,added figure,added comments
Phys.Lett.B694:430-434,2011
10.1016/j.physletb.2010.10.004
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been shown in a recent paper that the Higgs quartic and Yukawa sectors of the Standard Model (SM) with a heavy fourth generation exhibit at a two-loop level a quasi fixed point structure instead of the one-loop Landau singularity and which could be located in the TeV region, a scale which is denoted by $\Lambda_{FP} $ in this paper. This provides the possibility of the existence of a TeV-scale physical cutoff endowed with several implications. In the vicinity of this quasi fixed point bound states and Higgs-like condensates made up of the 4th generation quarks and leptons get formed. It implies the possibility of a dynamical electroweak symmetry breaking generated by 4th generation condensates. The quasi fixed points also hint at at a possible restoration of scale symmetry at $\Lambda_{FP} $ and above and the emergence of a theory which could be deeper than the SM.
[ { "created": "Thu, 19 Nov 2009 20:53:32 GMT", "version": "v1" }, { "created": "Tue, 21 Dec 2010 17:39:42 GMT", "version": "v2" } ]
2011-04-20
[ [ "Hung", "P. Q.", "" ], [ "Xiong", "Chi", "" ] ]
It has been shown in a recent paper that the Higgs quartic and Yukawa sectors of the Standard Model (SM) with a heavy fourth generation exhibit at a two-loop level a quasi fixed point structure instead of the one-loop Landau singularity and which could be located in the TeV region, a scale which is denoted by $\Lambda_{FP} $ in this paper. This provides the possibility of the existence of a TeV-scale physical cutoff endowed with several implications. In the vicinity of this quasi fixed point bound states and Higgs-like condensates made up of the 4th generation quarks and leptons get formed. It implies the possibility of a dynamical electroweak symmetry breaking generated by 4th generation condensates. The quasi fixed points also hint at at a possible restoration of scale symmetry at $\Lambda_{FP} $ and above and the emergence of a theory which could be deeper than the SM.
hep-ph/0409023
Cyrille Marquet
Cyrille Marquet
A QCD dipole formalism for forward-gluon production
13 pages, 3 figures, Section II expanded, version to be published in NPB
Nucl.Phys. B705 (2005) 319-338
10.1016/j.nuclphysb.2004.11.015
null
hep-ph
null
We derive inclusive and diffractive forward-gluon production in the scattering of a $q\bar{q}$ dipole off an arbitrary target in the high-energy eikonal approximation, suitable to study the saturation regime. We show how the inclusive cross-section is related to the total cross-section for the scattering of a colorless pair of gluons on the target: the gluon-production cross-section can be expressed as a convolution between this $gg$ dipole total cross-section and a dipole distribution. We then consider as an application the forward-jet production from an incident hadron and describe forward-jet production at HERA and Mueller-Navelet jets at Tevatron or LHC. We show how these measurements are related to the $q\bar{q}-gg$ or $gg-gg$ dipole-dipole cross-sections and why they are therefore well-suited for studying high-energy scattering in QCD.
[ { "created": "Thu, 2 Sep 2004 16:36:55 GMT", "version": "v1" }, { "created": "Wed, 24 Nov 2004 14:42:00 GMT", "version": "v2" } ]
2009-11-10
[ [ "Marquet", "Cyrille", "" ] ]
We derive inclusive and diffractive forward-gluon production in the scattering of a $q\bar{q}$ dipole off an arbitrary target in the high-energy eikonal approximation, suitable to study the saturation regime. We show how the inclusive cross-section is related to the total cross-section for the scattering of a colorless pair of gluons on the target: the gluon-production cross-section can be expressed as a convolution between this $gg$ dipole total cross-section and a dipole distribution. We then consider as an application the forward-jet production from an incident hadron and describe forward-jet production at HERA and Mueller-Navelet jets at Tevatron or LHC. We show how these measurements are related to the $q\bar{q}-gg$ or $gg-gg$ dipole-dipole cross-sections and why they are therefore well-suited for studying high-energy scattering in QCD.
hep-ph/0102230
Xin-Nian Wang
Xin-Nian Wang and Xiaofeng Guo
Multiple Parton Scattering in Nuclei: Parton Energy Loss
Final version published in Nucl. Phys. A. 40 pages in RevTex with 15 postscript figures
Nucl.Phys.A696:788-832,2001
10.1016/S0375-9474(01)01130-7
LBNL-47155
hep-ph nucl-th
null
Multiple parton scattering and induced parton energy loss is studied in deeply inelastic scattering (DIS) off nuclei. The effect of multiple scattering of a highly off-shell quark and the induced parton energy loss is expressed in terms of the modification to the quark fragmentation functions. We derive such modified quark fragmentation functions and their QCD evolution equations in DIS using generalized factorization of higher twist parton distributions. We consider double-hard, hard-soft parton scattering as well as their interferences in the same framework. The final result, which depends on both the diagonal and off-diagonal twist-four parton distributions in nuclei, demonstrates clearly the Landau-Pomeranchuk-Migdal interference features and predicts a unique nuclear modification of the quark fragmentation functions.
[ { "created": "Mon, 19 Feb 2001 08:12:18 GMT", "version": "v1" }, { "created": "Sat, 29 Dec 2001 22:02:19 GMT", "version": "v2" } ]
2014-11-17
[ [ "Wang", "Xin-Nian", "" ], [ "Guo", "Xiaofeng", "" ] ]
Multiple parton scattering and induced parton energy loss is studied in deeply inelastic scattering (DIS) off nuclei. The effect of multiple scattering of a highly off-shell quark and the induced parton energy loss is expressed in terms of the modification to the quark fragmentation functions. We derive such modified quark fragmentation functions and their QCD evolution equations in DIS using generalized factorization of higher twist parton distributions. We consider double-hard, hard-soft parton scattering as well as their interferences in the same framework. The final result, which depends on both the diagonal and off-diagonal twist-four parton distributions in nuclei, demonstrates clearly the Landau-Pomeranchuk-Migdal interference features and predicts a unique nuclear modification of the quark fragmentation functions.
1310.6352
Jan Heisig
Jan Heisig
Gravitino LSP and leptogenesis after the first LHC results
19 pages + references, 9 eps figures; v2: analysis improved, figures 2-5 updated, conclusions unchanged, presentation improved, references added, matches journal version
JCAP04(2014)023
10.1088/1475-7516/2014/04/023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supersymmetric scenarios where the lightest superparticle (LSP) is the gravitino are an attractive alternative to the widely studied case of a neutralino LSP. A strong motivation for a gravitino LSP arises from the possibility of achieving higher reheating temperatures and thus potentially allow for thermal leptogenesis. The predictions for the primordial abundances of light elements in the presence of a late decaying next-to-LSP (NSLP) as well as the currently measured dark matter abundance allow us to probe the cosmological viability of such a scenario. Here we consider a gravitino-stau scenario. Utilizing a pMSSM scan we work out the implications of the 7 and 8 TeV LHC results as well as other experimental and theoretical constraints on the highest reheating temperatures that are cosmologically allowed. Our analysis shows that points with T_R>10^9 GeV survive only in a very particular corner of the SUSY parameter space. Those spectra feature a distinct signature at colliders that could be looked at in the upcoming LHC run.
[ { "created": "Wed, 23 Oct 2013 20:00:00 GMT", "version": "v1" }, { "created": "Fri, 18 Apr 2014 20:04:35 GMT", "version": "v2" } ]
2014-04-24
[ [ "Heisig", "Jan", "" ] ]
Supersymmetric scenarios where the lightest superparticle (LSP) is the gravitino are an attractive alternative to the widely studied case of a neutralino LSP. A strong motivation for a gravitino LSP arises from the possibility of achieving higher reheating temperatures and thus potentially allow for thermal leptogenesis. The predictions for the primordial abundances of light elements in the presence of a late decaying next-to-LSP (NSLP) as well as the currently measured dark matter abundance allow us to probe the cosmological viability of such a scenario. Here we consider a gravitino-stau scenario. Utilizing a pMSSM scan we work out the implications of the 7 and 8 TeV LHC results as well as other experimental and theoretical constraints on the highest reheating temperatures that are cosmologically allowed. Our analysis shows that points with T_R>10^9 GeV survive only in a very particular corner of the SUSY parameter space. Those spectra feature a distinct signature at colliders that could be looked at in the upcoming LHC run.
1712.03830
Ye Xing
Yu-Ji Shi and Wei Wang and Ye Xing and Ji Xu
Weak Decays of Doubly Heavy Baryons: Multi-body Decay Channels
47pages, 1figure. arXiv admin note: substantial text overlap with arXiv:1707.06570
Eur. Phys. J. C, 78 (2018) 56
10.1140/epjc/s10052-018-5532-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The newly-discovered $\Xi_{cc}^{++}$ decays into the $ \Lambda_{c}^+ K^-\pi^+\pi^+$, but the experimental data has indicated that this decay is not saturated by any two-body intermediate state. In this work, we analyze the multi-body weak decays of doubly heavy baryons $\Xi_{cc}$, $\Omega_{cc}$, $\Xi_{bc}$, $\Omega_{bc}$, $\Xi_{bb}$ and $\Omega_{bb}$, in particular the three-body nonleptonic decays and four-body semileptonic decays. We classify various decay modes according to the quark-level transitions and present an estimate of the typical branching fractions for a few golden decay channels. Decay amplitudes are then parametrized in terms of a few SU(3) irreducible amplitudes. With these amplitudes, we find a number of relations for decay widths, which can be examined in future.
[ { "created": "Fri, 8 Dec 2017 11:16:15 GMT", "version": "v1" } ]
2018-01-26
[ [ "Shi", "Yu-Ji", "" ], [ "Wang", "Wei", "" ], [ "Xing", "Ye", "" ], [ "Xu", "Ji", "" ] ]
The newly-discovered $\Xi_{cc}^{++}$ decays into the $ \Lambda_{c}^+ K^-\pi^+\pi^+$, but the experimental data has indicated that this decay is not saturated by any two-body intermediate state. In this work, we analyze the multi-body weak decays of doubly heavy baryons $\Xi_{cc}$, $\Omega_{cc}$, $\Xi_{bc}$, $\Omega_{bc}$, $\Xi_{bb}$ and $\Omega_{bb}$, in particular the three-body nonleptonic decays and four-body semileptonic decays. We classify various decay modes according to the quark-level transitions and present an estimate of the typical branching fractions for a few golden decay channels. Decay amplitudes are then parametrized in terms of a few SU(3) irreducible amplitudes. With these amplitudes, we find a number of relations for decay widths, which can be examined in future.
1712.04880
Shaikh Saad
Shaikh Saad
Fermion Masses and Mixings, Leptogenesis and Baryon Number Violation in Pati-Salam Model
48 pages, 10 figures. Replacement to match the published version
Nuclear Physics B 943 (2019) 114630
10.1016/j.nuclphysb.2019.114630
OSU-HEP-17-06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study a predictive model based on a partially unified theory possessing the gauge symmetry of the Pati-Salam group, $SU(2)_L\times SU(2)_R\times SU(4)_C$ supplemented by a global Peccei-Quinn symmetry, $U(1)_{PQ}$. A comprehensive analysis of the Higgs potential is carried out in a minimal set-up. The assumed Peccei-Quinn symmetry along with solving the strong CP problem, can provide axion as the dark matter candidate. This minimal set-up with limited number of Yukawa parameters can successfully incorporate the hierarchies in the charged fermion masses and mixings. The automatic existence of the heavy Majorana neutrinos generate the extremely small light neutrino masses through the seesaw mechanism, which is also responsible for producing the observed cosmological matter-antimatter asymmetry of the universe. We find interesting correlation between the low scale neutrino observables and the baryon asymmetry in this model. Baryon number violating nucleon decay processes mediated by the scalar diquarks and leptoquarks in this framework are found to be, $n,p\to \ell+m, \ell^c + m$ ($m=$ meson, $\ell=$ lepton, $\ell^c=$ antilepton) and $n,p\to \ell+\ell^c + \ell^c$. For some choice of the parameters of the theory, these decay rates can be within the observable range. Another baryon number violating process, the neutron-antineutron oscillation can also be in the observable range.
[ { "created": "Wed, 13 Dec 2017 17:49:05 GMT", "version": "v1" }, { "created": "Fri, 10 May 2019 23:38:22 GMT", "version": "v2" } ]
2019-05-14
[ [ "Saad", "Shaikh", "" ] ]
In this work we study a predictive model based on a partially unified theory possessing the gauge symmetry of the Pati-Salam group, $SU(2)_L\times SU(2)_R\times SU(4)_C$ supplemented by a global Peccei-Quinn symmetry, $U(1)_{PQ}$. A comprehensive analysis of the Higgs potential is carried out in a minimal set-up. The assumed Peccei-Quinn symmetry along with solving the strong CP problem, can provide axion as the dark matter candidate. This minimal set-up with limited number of Yukawa parameters can successfully incorporate the hierarchies in the charged fermion masses and mixings. The automatic existence of the heavy Majorana neutrinos generate the extremely small light neutrino masses through the seesaw mechanism, which is also responsible for producing the observed cosmological matter-antimatter asymmetry of the universe. We find interesting correlation between the low scale neutrino observables and the baryon asymmetry in this model. Baryon number violating nucleon decay processes mediated by the scalar diquarks and leptoquarks in this framework are found to be, $n,p\to \ell+m, \ell^c + m$ ($m=$ meson, $\ell=$ lepton, $\ell^c=$ antilepton) and $n,p\to \ell+\ell^c + \ell^c$. For some choice of the parameters of the theory, these decay rates can be within the observable range. Another baryon number violating process, the neutron-antineutron oscillation can also be in the observable range.
hep-ph/0101175
Giulia Zanderighi
Andrea Banfi, Giulia Zanderighi
Interplay between perturbative and non-perturbative QCD in three-jet events
6 pages, 2 figures, talk given by G.Z. at the ISMD 2000 Conference, to be published by the World Scientific Publishing Company, Singapore
null
null
null
hep-ph
null
We present the perturbative (PT) and non-perturbative (NP) analysis of the cumulative out-of-event-plane momentum distribution in e+e- annihilation in the near-to-planar three-jet region. A physical interpretation based on simple QCD considerations and kinematical relations will be given, with the aim of extending the described techniques to other multi-jet processes and, possibly, to hadron-hadron collisions.
[ { "created": "Tue, 16 Jan 2001 17:12:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Banfi", "Andrea", "" ], [ "Zanderighi", "Giulia", "" ] ]
We present the perturbative (PT) and non-perturbative (NP) analysis of the cumulative out-of-event-plane momentum distribution in e+e- annihilation in the near-to-planar three-jet region. A physical interpretation based on simple QCD considerations and kinematical relations will be given, with the aim of extending the described techniques to other multi-jet processes and, possibly, to hadron-hadron collisions.
hep-ph/0101080
Markus Diehl
Markus Diehl
Exclusive QCD
10 pages, Talk presented at RADCOR-2000, Carmel, CA, Sep. 2000. Figure 4b corrected
null
null
DESY-01-001
hep-ph
null
I give a brief introduction to the physics of generalized parton distributions and distribution amplitudes. I then report on the status of the calculation of radiative corrections for the exclusive processes where these quantities occur.
[ { "created": "Tue, 9 Jan 2001 15:12:46 GMT", "version": "v1" }, { "created": "Mon, 15 Jan 2001 16:38:48 GMT", "version": "v2" } ]
2007-05-23
[ [ "Diehl", "Markus", "" ] ]
I give a brief introduction to the physics of generalized parton distributions and distribution amplitudes. I then report on the status of the calculation of radiative corrections for the exclusive processes where these quantities occur.
1712.08162
Valerio Bertone Dr
Valerio Bertone and Michiel Botje
A C++ interface to QCDNUM
6 pages
null
null
null
hep-ph cs.MS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this document we report on the recent development of a C++ interface to the FORTRAN-based evolution program QCDNUM. A short description of the interface is given with a few basic examples of its usage.
[ { "created": "Thu, 21 Dec 2017 08:20:43 GMT", "version": "v1" } ]
2017-12-25
[ [ "Bertone", "Valerio", "" ], [ "Botje", "Michiel", "" ] ]
In this document we report on the recent development of a C++ interface to the FORTRAN-based evolution program QCDNUM. A short description of the interface is given with a few basic examples of its usage.
1008.0642
Christopher D. Carone
Christopher D. Carone, Joshua Erlich and Reinard Primulando (William and Mary)
Decaying Dark Matter from Dark Instantons
19 pages LaTeX, 3 eps figures. v2,v3: references added
Phys.Rev.D82:055028,2010
10.1103/PhysRevD.82.055028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct an explicit, TeV-scale model of decaying dark matter in which the approximate stability of the dark matter candidate is a consequence of a global symmetry that is broken only by instanton-induced operators generated by a non-Abelian dark gauge group. The dominant dark matter decay channels are to standard model leptons. Annihilation of the dark matter to standard model states occurs primarily through the Higgs portal. We show that the mass and lifetime of the dark matter candidate in this model can be chosen to be consistent with the values favored by fits to data from the PAMELA and Fermi LAT experiments.
[ { "created": "Tue, 3 Aug 2010 20:00:37 GMT", "version": "v1" }, { "created": "Tue, 10 Aug 2010 01:30:11 GMT", "version": "v2" }, { "created": "Wed, 22 Sep 2010 20:11:13 GMT", "version": "v3" } ]
2014-11-21
[ [ "Carone", "Christopher D.", "", "William\n and Mary" ], [ "Erlich", "Joshua", "", "William\n and Mary" ], [ "Primulando", "Reinard", "", "William\n and Mary" ] ]
We construct an explicit, TeV-scale model of decaying dark matter in which the approximate stability of the dark matter candidate is a consequence of a global symmetry that is broken only by instanton-induced operators generated by a non-Abelian dark gauge group. The dominant dark matter decay channels are to standard model leptons. Annihilation of the dark matter to standard model states occurs primarily through the Higgs portal. We show that the mass and lifetime of the dark matter candidate in this model can be chosen to be consistent with the values favored by fits to data from the PAMELA and Fermi LAT experiments.
hep-ph/0011072
Hungchong Kim
Hungchong Kim, Su Houng Lee and Makoto Oka
Proper construction of the continuum in light-cone QCD sum rules
12 pages including 3 figures, substantially revised, version to be published in Progress of Theoretical Physics
Prog.Theor.Phys. 109 (2003) 371-381
10.1143/PTP.109.371
null
hep-ph nucl-th
null
A proper way of subtracting the continuum contributions in light-cone QCD sum rules (LCQSR) is demonstrated. Specifically, we calculate the continuum corresponding to a typical OPE appearing in LCQSR by properly combining the double dispersion relation with QCD duality. We demonstrate how the subtraction terms can spuriously contribute to the sum rules. In the limit of zero external momentum, taking out the spurious continuum is found to yield the sum rules using the single-variable dispersion relation. The continuum factor constructed in this way differs from the one appearing in usual LCQSR. The difference substantially affects the extraction of hadronic parameters from the correlation function involving baryon currents.
[ { "created": "Mon, 6 Nov 2000 10:31:22 GMT", "version": "v1" }, { "created": "Tue, 17 Apr 2001 06:27:15 GMT", "version": "v2" }, { "created": "Thu, 27 Feb 2003 01:51:17 GMT", "version": "v3" } ]
2009-10-31
[ [ "Kim", "Hungchong", "" ], [ "Lee", "Su Houng", "" ], [ "Oka", "Makoto", "" ] ]
A proper way of subtracting the continuum contributions in light-cone QCD sum rules (LCQSR) is demonstrated. Specifically, we calculate the continuum corresponding to a typical OPE appearing in LCQSR by properly combining the double dispersion relation with QCD duality. We demonstrate how the subtraction terms can spuriously contribute to the sum rules. In the limit of zero external momentum, taking out the spurious continuum is found to yield the sum rules using the single-variable dispersion relation. The continuum factor constructed in this way differs from the one appearing in usual LCQSR. The difference substantially affects the extraction of hadronic parameters from the correlation function involving baryon currents.
hep-ph/0005228
Sanjay Reddy
Gregory W. Carter and Sanjay Reddy
Neutrino Propagation In Color Superconducting Quark Matter
12 pages, 5 figures
Phys.Rev. D62 (2000) 103002
10.1103/PhysRevD.62.103002
null
hep-ph astro-ph nucl-th
null
We calculate the neutrino mean free path in color superconducting quark matter, and employ it to study the cooling of matter via neutrino diffusion in the superconducting phase as compared to a free quark phase. The cooling process slows when quark matter undergoes a second order phase transition to a superconducting phase at the critical temperature $T_c$. Cooling subsequently accelerates as the temperature decreases below $T_c$. This will directly impact the early evolution of a newly born neutron star should its core contain quark matter. Consequently, there may be observable changes in the early neutrino emission which would provide evidence for superconductivity in hot and dense matter.
[ { "created": "Tue, 23 May 2000 21:35:12 GMT", "version": "v1" } ]
2009-10-31
[ [ "Carter", "Gregory W.", "" ], [ "Reddy", "Sanjay", "" ] ]
We calculate the neutrino mean free path in color superconducting quark matter, and employ it to study the cooling of matter via neutrino diffusion in the superconducting phase as compared to a free quark phase. The cooling process slows when quark matter undergoes a second order phase transition to a superconducting phase at the critical temperature $T_c$. Cooling subsequently accelerates as the temperature decreases below $T_c$. This will directly impact the early evolution of a newly born neutron star should its core contain quark matter. Consequently, there may be observable changes in the early neutrino emission which would provide evidence for superconductivity in hot and dense matter.
1606.09513
Leonard S. Kisslinger
Leonard S. Kisslinger, Debasish Das
$\Psi(2S)$ and $\Upsilon(3S)$ Suppression in p-Pb 8 TeV Collisions and Mixed Heavy Quark Hybrid Mesons
5 pages,no figures
Int. J. Theoretical Physics, 55. 5152 (2016
10.1007/s10773-016-3136-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This brief report is an extension of a previus publication on $\Psi(2S)$ to $J/\Psi(1S)$ suppression in p-Pb collisions at 5.02 TeV to estimate $\Psi(2S)$ to $J/\Psi(1S)$ and $\Upsilon(3S)$ to $\Upsilon(1S)$ suppression via p-Pb collisions at 8 TeV as proposed by the LHCb.
[ { "created": "Tue, 7 Jun 2016 17:17:55 GMT", "version": "v1" } ]
2016-11-21
[ [ "Kisslinger", "Leonard S.", "" ], [ "Das", "Debasish", "" ] ]
This brief report is an extension of a previus publication on $\Psi(2S)$ to $J/\Psi(1S)$ suppression in p-Pb collisions at 5.02 TeV to estimate $\Psi(2S)$ to $J/\Psi(1S)$ and $\Upsilon(3S)$ to $\Upsilon(1S)$ suppression via p-Pb collisions at 8 TeV as proposed by the LHCb.
1404.2746
Angel Gomez Nicola
A. Gomez Nicola and R. Torres Andres
Electromagnetic effects in the pion dispersion relation at finite temperature
28 pages, 7 figures. Version accepted for publication in Physical Review D
Phys. Rev. D 89, 116009 (2014)
10.1103/PhysRevD.89.116009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the charged-neutral pion self-energy difference at finite temperature. Within Chiral Perturbation Theory we extend previous analysis in the chiral and soft pion limits. Our analysis with physical masses leads to additional contributions for temperatures typical of a meson gas, including a momentum-dependent function for the self energy. In addition, a nonzero imaginary part arises, which we define consistently in the Coulomb gauge and comes from an infrared enhanced contribution due to thermal bath photons. For distributions typical of a heavy-ion meson gas, the charged and neutral pion masses and their difference depend on temperature through slowly increasing functions. Chiral symmetry restoration is ultimately responsible for keeping the corrections smooth and compatible with observed pion spectra. We study phenomenological effects related to the electromagnetic damping leading to corrections for transport coefficients and neutral-charged mean free times differences. An important aspect is the connection with chiral symmetry restoration through the relation of the pion mass difference with the vector-axial spectral function difference, which holds at $T=0$ due to a sum rule in the chiral and soft pion limits. We analyze the modifications of that sum rule including nonzero pion masses and temperature, up to order $T^2$ and $M_\pi^2$. Both effects produce terms making the pion mass difference grow against chiral-restoring decreasing contributions. Finally, we analyze the corrections to the previous ChPT and sum rule results within the resonance saturation framework at finite temperature, including explicitly $\rho$ and $a_1$ exchanges. Our results show that the ChPT result is robust at low and intermediate temperatures, the leading corrections being of order $T^2 M_\pi^2/M_R^2$ with $M_R$ the involved resonance masses.
[ { "created": "Thu, 10 Apr 2014 09:22:53 GMT", "version": "v1" }, { "created": "Wed, 23 Apr 2014 20:39:29 GMT", "version": "v2" }, { "created": "Wed, 4 Jun 2014 06:01:44 GMT", "version": "v3" } ]
2014-06-18
[ [ "Nicola", "A. Gomez", "" ], [ "Andres", "R. Torres", "" ] ]
We investigate the charged-neutral pion self-energy difference at finite temperature. Within Chiral Perturbation Theory we extend previous analysis in the chiral and soft pion limits. Our analysis with physical masses leads to additional contributions for temperatures typical of a meson gas, including a momentum-dependent function for the self energy. In addition, a nonzero imaginary part arises, which we define consistently in the Coulomb gauge and comes from an infrared enhanced contribution due to thermal bath photons. For distributions typical of a heavy-ion meson gas, the charged and neutral pion masses and their difference depend on temperature through slowly increasing functions. Chiral symmetry restoration is ultimately responsible for keeping the corrections smooth and compatible with observed pion spectra. We study phenomenological effects related to the electromagnetic damping leading to corrections for transport coefficients and neutral-charged mean free times differences. An important aspect is the connection with chiral symmetry restoration through the relation of the pion mass difference with the vector-axial spectral function difference, which holds at $T=0$ due to a sum rule in the chiral and soft pion limits. We analyze the modifications of that sum rule including nonzero pion masses and temperature, up to order $T^2$ and $M_\pi^2$. Both effects produce terms making the pion mass difference grow against chiral-restoring decreasing contributions. Finally, we analyze the corrections to the previous ChPT and sum rule results within the resonance saturation framework at finite temperature, including explicitly $\rho$ and $a_1$ exchanges. Our results show that the ChPT result is robust at low and intermediate temperatures, the leading corrections being of order $T^2 M_\pi^2/M_R^2$ with $M_R$ the involved resonance masses.
2208.11295
Debasish Borah
Devabrat Mahanta, Debasish Borah
WIMPy Leptogenesis in Non-Standard Cosmologies
50 pages, 21 captioned figures, matches version accepted for publication in JCAP
null
10.1088/1475-7516/2023/03/049
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possibility of generating baryon asymmetry of the universe from dark matter (DM) annihilations during non-standard cosmological epochs. Considering the DM to be of weakly interacting massive particle (WIMP) type, the generation of baryon asymmetry via leptogenesis route is studied where WIMP DM annihilation produces a non-zero lepton asymmetry. Adopting a minimal particle physics model to realise this along with non-zero light neutrino masses, we consider three different types of non-standard cosmic history namely, (i) fast expanding universe, (ii) early matter domination and (iii) scalar-tensor theory of gravity. By solving the appropriate Boltzmann equations incorporating such non-standard history, we find that the allowed parameter space consistent with DM relic and observed baryon asymmetry gets enlarged with the possibility of lower DM mass in some scenarios. While such lighter DM can face further scrutiny at direct search experiments, the non-standard epochs offer complementary probes on their own.
[ { "created": "Wed, 24 Aug 2022 04:20:00 GMT", "version": "v1" }, { "created": "Sun, 5 Mar 2023 05:23:35 GMT", "version": "v2" } ]
2023-03-29
[ [ "Mahanta", "Devabrat", "" ], [ "Borah", "Debasish", "" ] ]
We study the possibility of generating baryon asymmetry of the universe from dark matter (DM) annihilations during non-standard cosmological epochs. Considering the DM to be of weakly interacting massive particle (WIMP) type, the generation of baryon asymmetry via leptogenesis route is studied where WIMP DM annihilation produces a non-zero lepton asymmetry. Adopting a minimal particle physics model to realise this along with non-zero light neutrino masses, we consider three different types of non-standard cosmic history namely, (i) fast expanding universe, (ii) early matter domination and (iii) scalar-tensor theory of gravity. By solving the appropriate Boltzmann equations incorporating such non-standard history, we find that the allowed parameter space consistent with DM relic and observed baryon asymmetry gets enlarged with the possibility of lower DM mass in some scenarios. While such lighter DM can face further scrutiny at direct search experiments, the non-standard epochs offer complementary probes on their own.
1912.08420
Jun He Prof.
Jun He, Yi Liu, Jun-Tao Zhu, Dian-Yong Chen
Y(4626) as a molecular state from interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$
7 pages, 2 figures
Eur.Phys.J.C 80 (2020) 3, 246
10.1140/epjc/s10052-020-7820-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, a new structure $Y(4626)$ was reported by the Belle Colloboration in the process $e^+e^-\to D_s^+D_{s1}(2536)^-$. In this work, we propose an assignment of the $Y(4626)$ as a ${D}^*_s\bar{D}_{s1}(2536)$ molecular state, which decays into the $D_s^+D_{s1}(2536)^-$ channel through a coupling between ${D}^*_s\bar{D}_{s1}(2536)$ and ${D}_s\bar{D}_{s1}(2536)$ channels. With the help of the heavy quark symmetry, the potential of the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$ is constructed within the one-boson-exchange model, and inserted into the quasipotential Bethe-Salpeter equation. The pole of obtained scattering amplitude is searched for in the complex plane, which corresponds to a molecular state from the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$. The results suggest that a pole is produced near the ${D}^*_s\bar{D}_{s1}(2536)$ threshold, which exhibits as a peak in the invariant mass spectrum of the ${D}_s\bar{D}_{s1}(2536)$ channel at about 4626 MeV. It obviously favors the $Y(4265)$ as a ${D}^*_s\bar{D}_{s1}(2536)$ molecular state. In the same model, other molecular states from the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$ are also predicted, which can be checked in future experiments.
[ { "created": "Wed, 18 Dec 2019 07:35:53 GMT", "version": "v1" }, { "created": "Wed, 15 Jul 2020 10:27:57 GMT", "version": "v2" } ]
2020-07-16
[ [ "He", "Jun", "" ], [ "Liu", "Yi", "" ], [ "Zhu", "Jun-Tao", "" ], [ "Chen", "Dian-Yong", "" ] ]
Recently, a new structure $Y(4626)$ was reported by the Belle Colloboration in the process $e^+e^-\to D_s^+D_{s1}(2536)^-$. In this work, we propose an assignment of the $Y(4626)$ as a ${D}^*_s\bar{D}_{s1}(2536)$ molecular state, which decays into the $D_s^+D_{s1}(2536)^-$ channel through a coupling between ${D}^*_s\bar{D}_{s1}(2536)$ and ${D}_s\bar{D}_{s1}(2536)$ channels. With the help of the heavy quark symmetry, the potential of the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$ is constructed within the one-boson-exchange model, and inserted into the quasipotential Bethe-Salpeter equation. The pole of obtained scattering amplitude is searched for in the complex plane, which corresponds to a molecular state from the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$. The results suggest that a pole is produced near the ${D}^*_s\bar{D}_{s1}(2536)$ threshold, which exhibits as a peak in the invariant mass spectrum of the ${D}_s\bar{D}_{s1}(2536)$ channel at about 4626 MeV. It obviously favors the $Y(4265)$ as a ${D}^*_s\bar{D}_{s1}(2536)$ molecular state. In the same model, other molecular states from the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$ are also predicted, which can be checked in future experiments.
0711.0200
Georg Weiglein
Georg Weiglein
SUSY in the Light of B Physics and Electroweak Precision Observables
4 pages, submitted for the SUSY07 proceedings
null
null
IPPP/07/77, DCPT/07/154
hep-ph
null
Indirect information about the possible scale of supersymmetry (SUSY) breaking can be obtained from the comparison of precisely measured observables (and also of exclusion limits) with accurate theory predictions incorporating SUSY loop corrections. Recent results are reviewed obtained from a combined analysis of the most sensitive electroweak precision observables (EWPO), M_W, sin^2_theta^eff, Gamma_Z, (g-2)_\mu and M_h, and B-physics observables (BPO), BR(b -> s \gamma), BR(B_s -> \mu^+\mu^-), BR(B_u -> \tau \nu_\tau) and \Delta M_{B_s}. Assuming that the lightest supersymmetric particle (LSP) provides the cold dark matter density preferred by WMAP and other cosmological data, \chi^2 fits are performed to the parameters of the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which the SUSY-breaking parameters are universal at the GUT scale, and the non-universal Higgs model (NUHM), in which this constraint is relaxed for the soft SUSY-breaking contributions to the Higgs masses. Within the CMSSM indirect bounds on the mass of the lightest CP-even Higgs boson are derived.
[ { "created": "Thu, 1 Nov 2007 19:33:12 GMT", "version": "v1" } ]
2007-11-02
[ [ "Weiglein", "Georg", "" ] ]
Indirect information about the possible scale of supersymmetry (SUSY) breaking can be obtained from the comparison of precisely measured observables (and also of exclusion limits) with accurate theory predictions incorporating SUSY loop corrections. Recent results are reviewed obtained from a combined analysis of the most sensitive electroweak precision observables (EWPO), M_W, sin^2_theta^eff, Gamma_Z, (g-2)_\mu and M_h, and B-physics observables (BPO), BR(b -> s \gamma), BR(B_s -> \mu^+\mu^-), BR(B_u -> \tau \nu_\tau) and \Delta M_{B_s}. Assuming that the lightest supersymmetric particle (LSP) provides the cold dark matter density preferred by WMAP and other cosmological data, \chi^2 fits are performed to the parameters of the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which the SUSY-breaking parameters are universal at the GUT scale, and the non-universal Higgs model (NUHM), in which this constraint is relaxed for the soft SUSY-breaking contributions to the Higgs masses. Within the CMSSM indirect bounds on the mass of the lightest CP-even Higgs boson are derived.
1209.3554
Yongseok Oh
Yong-Liang Ma, Ghil-Seok Yang, Yongseok Oh, Masayasu Harada
Skyrmions with vector mesons in the hidden local symmetry approach
REVTeX, 17 pages, 10 figures, to be published in Phys. Rev. D
Phys.Rev.D87:034023,2013
10.1103/PhysRevD.87.034023
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The roles of light $\rho$ and $\omega$ vector mesons in the Skyrmion are investigated in a chiral Lagrangian derived from the hidden local symmetry (HLS) up to $O(p^4)$ including the homogeneous Wess-Zumino (hWZ) terms. We write a general "master formula" that allows us to determine the parameters of the HLS Lagrangian from a class of holographic QCD models valid at large $N_c$ and $\lambda$ ('t Hooft constant) limit by integrating out the infinite towers of vector and axial-vector mesons other than the lowest $\rho$ and $\omega$ mesons. Within this approach we find that the physical properties of the Skyrmion as the solitonic description of baryons are \textit{independent} of the HLS parameter $a$. Therefore the only parameters of the model are the pion decay constant and the vector meson mass. Once determined in the meson sector, we have a totally parameter-free theory that allows us to study unequivocally the role of light vector mesons in the Skyrmion structure. We find, as suggested by Sutcliffe, that inclusion of the $\rho$ meson reduces the soliton mass, which makes the Skyrmion come closer to the Bogomol'nyi-Prasad-Sommerfield (BPS) soliton, but the role of the $\omega$ meson is found to increase the soliton mass. In a stark contrast, the $\Delta$-$N$ mass difference, which is determined by the moment of inertia in adiabatic collective quantization of the Skyrmion, is increased by the $\rho$ vector meson, while it is reduced by the inclusion of the $\omega$ meson. All these observations show the importance of the $\omega$ meson in the properties of the nucleon and nuclear matter in the Skyrme model.
[ { "created": "Mon, 17 Sep 2012 05:24:30 GMT", "version": "v1" }, { "created": "Sun, 3 Feb 2013 06:38:25 GMT", "version": "v2" } ]
2015-06-11
[ [ "Ma", "Yong-Liang", "" ], [ "Yang", "Ghil-Seok", "" ], [ "Oh", "Yongseok", "" ], [ "Harada", "Masayasu", "" ] ]
The roles of light $\rho$ and $\omega$ vector mesons in the Skyrmion are investigated in a chiral Lagrangian derived from the hidden local symmetry (HLS) up to $O(p^4)$ including the homogeneous Wess-Zumino (hWZ) terms. We write a general "master formula" that allows us to determine the parameters of the HLS Lagrangian from a class of holographic QCD models valid at large $N_c$ and $\lambda$ ('t Hooft constant) limit by integrating out the infinite towers of vector and axial-vector mesons other than the lowest $\rho$ and $\omega$ mesons. Within this approach we find that the physical properties of the Skyrmion as the solitonic description of baryons are \textit{independent} of the HLS parameter $a$. Therefore the only parameters of the model are the pion decay constant and the vector meson mass. Once determined in the meson sector, we have a totally parameter-free theory that allows us to study unequivocally the role of light vector mesons in the Skyrmion structure. We find, as suggested by Sutcliffe, that inclusion of the $\rho$ meson reduces the soliton mass, which makes the Skyrmion come closer to the Bogomol'nyi-Prasad-Sommerfield (BPS) soliton, but the role of the $\omega$ meson is found to increase the soliton mass. In a stark contrast, the $\Delta$-$N$ mass difference, which is determined by the moment of inertia in adiabatic collective quantization of the Skyrmion, is increased by the $\rho$ vector meson, while it is reduced by the inclusion of the $\omega$ meson. All these observations show the importance of the $\omega$ meson in the properties of the nucleon and nuclear matter in the Skyrme model.
1007.1993
Gino Isidori
Andrzej J. Buras, Katrin Gemmler, Gino Isidori
Quark flavour mixing with right-handed currents: an effective theory approach
39 pages, 3 figs
null
10.1016/j.nuclphysb.2010.09.021
TUM-HEP-765/10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The impact of right-handed currents in both charged- and neutral-current flavour-violating processes is analysed by means of an effective theory approach. More explicitly, we analyse the structure of dimension-six operators assuming a left-right symmetric flavour group, commuting with an underlying $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ global symmetry, broken only by two Yukawa couplings. The model contains a new unitary matrix controlling flavour-mixing in the right-handed sector. We determine the structure of this matrix by charged-current data, where the tension between inclusive and exclusive determinations of $|V_{ub}|$ can be solved. Having determined the size and the flavour structure of right-handed currents, we investigate how they would manifest themselves in neutral current processes, including particle-antiparticle mixing, $Z\to b \bar b$, $B_{s,d}\to \mu^+\mu^-$, $B\to {Xs,K,K*} \nu\bar\nu$, and $K\to \pi\nu\bar\nu$ decays. The possibility to explain a non-standard CP-violating phase in $B_s$ mixing in this context, and the comparison with other predictive new-physics frameworks addressing the same problem, is also discussed. While a large $S_{\psi \phi}$ asymmetry can easily be accommodated, we point out a tension in this framework between $|V_{ub}|$ and $S_{\psi K}$.
[ { "created": "Mon, 12 Jul 2010 20:54:45 GMT", "version": "v1" } ]
2015-05-19
[ [ "Buras", "Andrzej J.", "" ], [ "Gemmler", "Katrin", "" ], [ "Isidori", "Gino", "" ] ]
The impact of right-handed currents in both charged- and neutral-current flavour-violating processes is analysed by means of an effective theory approach. More explicitly, we analyse the structure of dimension-six operators assuming a left-right symmetric flavour group, commuting with an underlying $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ global symmetry, broken only by two Yukawa couplings. The model contains a new unitary matrix controlling flavour-mixing in the right-handed sector. We determine the structure of this matrix by charged-current data, where the tension between inclusive and exclusive determinations of $|V_{ub}|$ can be solved. Having determined the size and the flavour structure of right-handed currents, we investigate how they would manifest themselves in neutral current processes, including particle-antiparticle mixing, $Z\to b \bar b$, $B_{s,d}\to \mu^+\mu^-$, $B\to {Xs,K,K*} \nu\bar\nu$, and $K\to \pi\nu\bar\nu$ decays. The possibility to explain a non-standard CP-violating phase in $B_s$ mixing in this context, and the comparison with other predictive new-physics frameworks addressing the same problem, is also discussed. While a large $S_{\psi \phi}$ asymmetry can easily be accommodated, we point out a tension in this framework between $|V_{ub}|$ and $S_{\psi K}$.
1512.05359
David McKeen
David McKeen, Ann E. Nelson
CP Violating Baryon Oscillations
8 pages, 2 figures. v2: version to appear in PRD
Phys. Rev. D 94, 076002 (2016)
10.1103/PhysRevD.94.076002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We enumerate the conditions necessary for $CP$ violation to be manifest in $n$-$\bar n$ oscillations, and build a simple model that can give rise to such effects. We discuss a possible connection between neutron oscillations and dark matter, provided the mass of the latter lies between $m_p-m_e$ and $m_p+m_e$. We apply our results to a possible baryogenesis scenario involving $CP$ violation in the oscillations of the $\Xi^0$.
[ { "created": "Wed, 16 Dec 2015 21:00:06 GMT", "version": "v1" }, { "created": "Sun, 11 Sep 2016 03:02:17 GMT", "version": "v2" } ]
2016-10-12
[ [ "McKeen", "David", "" ], [ "Nelson", "Ann E.", "" ] ]
We enumerate the conditions necessary for $CP$ violation to be manifest in $n$-$\bar n$ oscillations, and build a simple model that can give rise to such effects. We discuss a possible connection between neutron oscillations and dark matter, provided the mass of the latter lies between $m_p-m_e$ and $m_p+m_e$. We apply our results to a possible baryogenesis scenario involving $CP$ violation in the oscillations of the $\Xi^0$.
1310.7579
Archana Anandakrishnan
Archana Anandakrishnan, Kuver Sinha
On the Viability of Thermal Well-Tempered Dark Matter in SUSY GUTs
Minor updates and added references
Phys. Rev. D 89, 055015 (2014)
10.1103/PhysRevD.89.055015
OHSTPY-HEP-T-13-005
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a scenario with heavy supersymmetric sfermions and decoupled supersymmetric Higgs sector, a well tempered neutralino is the remaining candidate for thermal single-component sub-TeV dark matter. Well tempered neutralinos are studied in the context of supersymmetric grand unified theories with third family Yukawa coupling unification. A global chi^2 analysis is performed, including the observables MW, MZ, GF, alpha_em, alpha_s(MZ), Mt, mb(mb), Mtau, b -> s gamma, BR(Bs -> mu^+ mu^-), Mh and Omegah^2. Tensions in simultaneously fitting the Higgs and bottom quark masses while also avoiding gluino mass bounds from the LHC disfavors light Higgsinos with mass < 500 GeV, ruling out light Bino/Higgsino dark matter candidates. Bino/Wino/Higgsino and Bino/Wino candidates fare somewhat better although they are fine-tuned and require departure from GUT scale gaugino mass universality (the example chosen here is the mixed modulus-anomaly pattern). Implications for dark matter direct detection of these models as well as collider signatures are briefly discussed. Independent of the thermal dark matter viability, these models will be severely constrained by the absence of a gluino at the next run of LHC.
[ { "created": "Mon, 28 Oct 2013 20:00:00 GMT", "version": "v1" }, { "created": "Fri, 8 Nov 2013 18:16:39 GMT", "version": "v2" } ]
2014-03-26
[ [ "Anandakrishnan", "Archana", "" ], [ "Sinha", "Kuver", "" ] ]
In a scenario with heavy supersymmetric sfermions and decoupled supersymmetric Higgs sector, a well tempered neutralino is the remaining candidate for thermal single-component sub-TeV dark matter. Well tempered neutralinos are studied in the context of supersymmetric grand unified theories with third family Yukawa coupling unification. A global chi^2 analysis is performed, including the observables MW, MZ, GF, alpha_em, alpha_s(MZ), Mt, mb(mb), Mtau, b -> s gamma, BR(Bs -> mu^+ mu^-), Mh and Omegah^2. Tensions in simultaneously fitting the Higgs and bottom quark masses while also avoiding gluino mass bounds from the LHC disfavors light Higgsinos with mass < 500 GeV, ruling out light Bino/Higgsino dark matter candidates. Bino/Wino/Higgsino and Bino/Wino candidates fare somewhat better although they are fine-tuned and require departure from GUT scale gaugino mass universality (the example chosen here is the mixed modulus-anomaly pattern). Implications for dark matter direct detection of these models as well as collider signatures are briefly discussed. Independent of the thermal dark matter viability, these models will be severely constrained by the absence of a gluino at the next run of LHC.
hep-ph/9903445
null
S.V. Molodtsov, A.M. Snigirev, G.M. Zinovjev
Towards Phonon-Like Excitations of Instanton Liquid
6 pages Rep. no:
Phys.Rev. D60 (1999) 056006
10.1103/PhysRevD.60.056006
null
hep-ph hep-lat hep-th nucl-th
null
The phonon-like excitations of (anti)-instanton ($\bar II$) liquid due to adiabatic variations of vacuum wave functions are studied in this paper. The kinetic energy term is found and the proper effective Lagrangian for such excitations is evaluated. The properties of their spectrum, while corresponding masses are defined by $\Lambda_{QCD}$, are investigated.
[ { "created": "Mon, 22 Mar 1999 15:02:38 GMT", "version": "v1" } ]
2009-10-31
[ [ "Molodtsov", "S. V.", "" ], [ "Snigirev", "A. M.", "" ], [ "Zinovjev", "G. M.", "" ] ]
The phonon-like excitations of (anti)-instanton ($\bar II$) liquid due to adiabatic variations of vacuum wave functions are studied in this paper. The kinetic energy term is found and the proper effective Lagrangian for such excitations is evaluated. The properties of their spectrum, while corresponding masses are defined by $\Lambda_{QCD}$, are investigated.
0711.2789
Antonio M. Garcia-Garcia
Antonio M. Garcia-Garcia, James C. Osborn
Is the chiral phase transition induced by a metal-insulator transition?
5 pages, 4 figures. Contributions to the proceedings of ``Infrared QCD in Rio: Propagators, Condensates and Topological Effects (IRQCD 2006)'', Rio de Janeiro, Brazil, 5-9 Jun 2006
Braz.J.Phys.37:246-250,2007
null
null
hep-ph
null
We investigate the QCD Dirac operator with gauge configurations given by a liquid of instantons in the region of temperatures about the chiral phase transition. Both the quenched and unquenched cases are examined in detail. We present evidence of a localization transition in the low lying modes of the Dirac operator around the same temperature as the chiral phase transition. Thus both level statistics and eigenvectors of the QCD Dirac operator at the chiral phase transition have similar properties than those of a disordered conductor at the metal-insulator transition. This strongly suggests the phenomenon of Anderson localization (localization by destructive quantum interference) is the leading physical mechanism in the restoration of the chiral symmetry. Finally we argue that our findings are not in principle restricted to the ILM approximation and may also be found in lattice simulations.
[ { "created": "Sun, 18 Nov 2007 15:07:44 GMT", "version": "v1" } ]
2008-11-26
[ [ "Garcia-Garcia", "Antonio M.", "" ], [ "Osborn", "James C.", "" ] ]
We investigate the QCD Dirac operator with gauge configurations given by a liquid of instantons in the region of temperatures about the chiral phase transition. Both the quenched and unquenched cases are examined in detail. We present evidence of a localization transition in the low lying modes of the Dirac operator around the same temperature as the chiral phase transition. Thus both level statistics and eigenvectors of the QCD Dirac operator at the chiral phase transition have similar properties than those of a disordered conductor at the metal-insulator transition. This strongly suggests the phenomenon of Anderson localization (localization by destructive quantum interference) is the leading physical mechanism in the restoration of the chiral symmetry. Finally we argue that our findings are not in principle restricted to the ILM approximation and may also be found in lattice simulations.
hep-ph/9306263
null
G.E. Forden, DZERO Collaboration
The Search for Large Rapidity Gaps Between Jets by DZERO
3 pages, AZPH-EXP/93-01
null
null
null
hep-ph
null
We have searched for high Pt (>40 GeV/c) jet events in ppbar collisions at the Fermilab TEVATRON (S**1/2 = 1800 GeV/c2) which have large pseudo-rapidity differences between the jets and are consistent with zero particle production from the underlying event. Preliminary analysis indicates that a significant fraction of these events with "voids" are present. (3 pages of plain text, 7 Figures available on request from the author)
[ { "created": "Fri, 11 Jun 1993 16:00:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Forden", "G. E.", "" ], [ "Collaboration", "DZERO", "" ] ]
We have searched for high Pt (>40 GeV/c) jet events in ppbar collisions at the Fermilab TEVATRON (S**1/2 = 1800 GeV/c2) which have large pseudo-rapidity differences between the jets and are consistent with zero particle production from the underlying event. Preliminary analysis indicates that a significant fraction of these events with "voids" are present. (3 pages of plain text, 7 Figures available on request from the author)
2302.09889
Narmin Nasibova
Narmin Nasibova
Isospin symmetry of $\omega$ meson in the soft-wall model of holographic QCD at finite temperature
19 pages, 11 figures. arXiv admin note: text overlap with arXiv:2103.10494
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Coupling constants of $\rho$- and $\omega$- meson-nucleon are related with each other by isospin relation. In present work, it is aimed at studying the violation (if it exists) of isospin symmetry of the $\omega$-meson and to study the temperature dependence of $\omega$-meson-nucleon-delta and $\omega$-meson-delta coupling constants using the soft-wall model of holographic QCD. Firstly, the coupling constants are obtained by applying the profile functions of the vector and fermion fields to the model at a finite temperature. The interaction Lagrangian is written, including the minimum and magnetic interactions of vector and fermion fields which is defined in the bulk of the 5-dimensional AdS space-time. Secondly, the temperature dependence of the coupling constants $g_{\omega N N}(T)$, $g_{\omega \Delta \Delta}(T)$ and $g_{\omega N \Delta}(T)$ has been plotted. Comparing $g_{\omega N N}(T)$ with the coupling constant $g_{\rho NN}(T)$, it obtained that the isospin symmetry of the omega meson is not violated at the finite temperature. It is also observed that the coupling constants of the $\omega$ vector meson with baryons decreases with increasing temperature, and this coupling constant becomes zero near the Hawking phase transition temperature.
[ { "created": "Mon, 20 Feb 2023 10:36:02 GMT", "version": "v1" } ]
2023-02-21
[ [ "Nasibova", "Narmin", "" ] ]
Coupling constants of $\rho$- and $\omega$- meson-nucleon are related with each other by isospin relation. In present work, it is aimed at studying the violation (if it exists) of isospin symmetry of the $\omega$-meson and to study the temperature dependence of $\omega$-meson-nucleon-delta and $\omega$-meson-delta coupling constants using the soft-wall model of holographic QCD. Firstly, the coupling constants are obtained by applying the profile functions of the vector and fermion fields to the model at a finite temperature. The interaction Lagrangian is written, including the minimum and magnetic interactions of vector and fermion fields which is defined in the bulk of the 5-dimensional AdS space-time. Secondly, the temperature dependence of the coupling constants $g_{\omega N N}(T)$, $g_{\omega \Delta \Delta}(T)$ and $g_{\omega N \Delta}(T)$ has been plotted. Comparing $g_{\omega N N}(T)$ with the coupling constant $g_{\rho NN}(T)$, it obtained that the isospin symmetry of the omega meson is not violated at the finite temperature. It is also observed that the coupling constants of the $\omega$ vector meson with baryons decreases with increasing temperature, and this coupling constant becomes zero near the Hawking phase transition temperature.
1605.08267
Diego Aristizabal
D. Aristizabal Sierra, C. Simoes, D. Wegman
Radiative accidental matter
24 pages, 6 figures, 4 tables. Few typos corrected and references added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Accidental matter models are scenarios where the beyond-the-standard model physics preserves all the standard model accidental and approximate symmetries up to a cutoff scale related with lepton number violation. We study such scenarios assuming that the new physics plays an active role in neutrino mass generation, and show that this unavoidably leads to radiatively induced neutrino masses. We systematically classify all possible models and determine their viability by studying electroweak precision data, big bang nucleosynthesis and electroweak perturbativity, finding that the latter places the most stringent constraints on the mass spectra. These results allow the identification of minimal radiative accidental matter models for which perturbativity is lost at high scales. We calculate radiative charged-lepton flavor violating processes in these setups, and show that $\mu\to e \gamma$ has a rate well within MEG sensitivity provided the lepton-number violating scale is at or below $10^6$ GeV, a value (naturally) assured by the radiative suppression mechanism. Sizeable $\tau\to \mu \gamma$ branching fractions within SuperKEKB sensitivity are possible for lower lepton-number breaking scales. We thus point out that these scenarios can be tested not only in direct searches but also in lepton-flavor violating experiments.
[ { "created": "Thu, 26 May 2016 13:28:03 GMT", "version": "v1" }, { "created": "Mon, 13 Jun 2016 21:44:53 GMT", "version": "v2" } ]
2016-06-15
[ [ "Sierra", "D. Aristizabal", "" ], [ "Simoes", "C.", "" ], [ "Wegman", "D.", "" ] ]
Accidental matter models are scenarios where the beyond-the-standard model physics preserves all the standard model accidental and approximate symmetries up to a cutoff scale related with lepton number violation. We study such scenarios assuming that the new physics plays an active role in neutrino mass generation, and show that this unavoidably leads to radiatively induced neutrino masses. We systematically classify all possible models and determine their viability by studying electroweak precision data, big bang nucleosynthesis and electroweak perturbativity, finding that the latter places the most stringent constraints on the mass spectra. These results allow the identification of minimal radiative accidental matter models for which perturbativity is lost at high scales. We calculate radiative charged-lepton flavor violating processes in these setups, and show that $\mu\to e \gamma$ has a rate well within MEG sensitivity provided the lepton-number violating scale is at or below $10^6$ GeV, a value (naturally) assured by the radiative suppression mechanism. Sizeable $\tau\to \mu \gamma$ branching fractions within SuperKEKB sensitivity are possible for lower lepton-number breaking scales. We thus point out that these scenarios can be tested not only in direct searches but also in lepton-flavor violating experiments.
1405.6078
Tuomas Hapola
Tuomas Hapola
Higgs Boson with Multiple Jets
4 pages, 5 figures, contribution to 49th Rencontres de Moriond on QCD and High Energy Interactions (Moriond QCD 2014)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The High Energy Jets (HEJ) framework accounts for large logarithms arising from the wide angle hard gluon emissions. The resummation in HEJ is based on an approximation to allow fast evaluation for arbitrary multiplicity. The approximation is motivated by the high energy limit and as such captures the leading logarithmic corrections in large invariant mass between the partons. These corrections are important when there is a large separation in rapidity between the produced jets. This situation arises in a Higgs boson plus jets analysis. Furthermore, HEJ includes matching to full tree level accuracy up to four jets. This talk will introduce the HEJ framework and discuss advances in the formal accuracy attained within HEJ, and the application to predictions for the production of Higgs boson plus jets.
[ { "created": "Fri, 23 May 2014 14:40:01 GMT", "version": "v1" } ]
2014-05-26
[ [ "Hapola", "Tuomas", "" ] ]
The High Energy Jets (HEJ) framework accounts for large logarithms arising from the wide angle hard gluon emissions. The resummation in HEJ is based on an approximation to allow fast evaluation for arbitrary multiplicity. The approximation is motivated by the high energy limit and as such captures the leading logarithmic corrections in large invariant mass between the partons. These corrections are important when there is a large separation in rapidity between the produced jets. This situation arises in a Higgs boson plus jets analysis. Furthermore, HEJ includes matching to full tree level accuracy up to four jets. This talk will introduce the HEJ framework and discuss advances in the formal accuracy attained within HEJ, and the application to predictions for the production of Higgs boson plus jets.
1110.6582
Artem Lipatov
A.V. Lipatov, M.A. Malyshev, N.P. Zotov
Drell-Yan lepton pair production at high energies in the kt-factorization approach
14 pages, 6 figures
JHEP 12, 117 (2011)
10.1007/JHEP12(2011)117
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of the kt-factorization approach, the production of unpolarized Drell-Yan lepton pair at high energies is studied. The consideration is based on the O(alpha) and $O(alpha alpha_s) off-shell partonic matrix elements with virtual photon and Z boson exchange. The calculations include leptonic decays of Z bosons with full spin correlations as well as gamma - Z interference. The unintegrated parton densities in a proton are determined by the Kimber-Martin-Ryskin prescription. Our numerical predictions are compared with the data taken by the D0, CDF and CMS collaborations at the Tevatron and LHC energies. Special attention is put on the specific angular distributions measured very recently by the CDF collaboration for the first time.
[ { "created": "Sun, 30 Oct 2011 06:21:51 GMT", "version": "v1" } ]
2015-06-03
[ [ "Lipatov", "A. V.", "" ], [ "Malyshev", "M. A.", "" ], [ "Zotov", "N. P.", "" ] ]
In the framework of the kt-factorization approach, the production of unpolarized Drell-Yan lepton pair at high energies is studied. The consideration is based on the O(alpha) and $O(alpha alpha_s) off-shell partonic matrix elements with virtual photon and Z boson exchange. The calculations include leptonic decays of Z bosons with full spin correlations as well as gamma - Z interference. The unintegrated parton densities in a proton are determined by the Kimber-Martin-Ryskin prescription. Our numerical predictions are compared with the data taken by the D0, CDF and CMS collaborations at the Tevatron and LHC energies. Special attention is put on the specific angular distributions measured very recently by the CDF collaboration for the first time.
hep-ph/0403012
Bohdan Grzadkowski
Patrizia Bucci, Bohdan Grzadkowski, Zygmunt Lalak and Radoslaw Matyszkiewicz
Electroweak symmetry breaking and radion stabilization in universal extra dimensions
20 pages, 2 figures, references added
JHEP 0404 (2004) 067
10.1088/1126-6708/2004/04/067
CERN-PH-TH/2004-036, IFT-2004-08
hep-ph
null
We discuss the stabilization of the scalar sector, including the radion, in the gauge model with one universal extra dimension, within Higgs and Higgsless scenarios. The stabilization occurs at the one-loop level, through the fermionic contribution to the effective potential; in the Higgs case, for stabilization to take place the bosonic contribution must be balanced by the fermionic one, hence the scales of these two cannot differ too much. However, there is no need for (softly broken) supersymmetry to achieve the stabilization - it can be arranged for a reasonably wide range of couplings and mass scales. The primary instability in the model is the run-away of the radion vacuum expectation value. It turns out that the requirement of the radion stability, in the Higgs case, favours a Higgs boson mass below 0.26 TeV, which is consistent with the Standard Model upper bound that follows from the electroweak precision measurements. The typical radion mass is of the order of 10^{-6} eV. The radion mass can be made larger by rising the scale of fermion masses, as clearly seen in the Higgsless case. The cosmological constant may be cancelled by suitable counterterms, in such a way that the stabilization is not affected.
[ { "created": "Mon, 1 Mar 2004 17:13:58 GMT", "version": "v1" }, { "created": "Mon, 22 Mar 2004 13:36:55 GMT", "version": "v2" } ]
2009-11-10
[ [ "Bucci", "Patrizia", "" ], [ "Grzadkowski", "Bohdan", "" ], [ "Lalak", "Zygmunt", "" ], [ "Matyszkiewicz", "Radoslaw", "" ] ]
We discuss the stabilization of the scalar sector, including the radion, in the gauge model with one universal extra dimension, within Higgs and Higgsless scenarios. The stabilization occurs at the one-loop level, through the fermionic contribution to the effective potential; in the Higgs case, for stabilization to take place the bosonic contribution must be balanced by the fermionic one, hence the scales of these two cannot differ too much. However, there is no need for (softly broken) supersymmetry to achieve the stabilization - it can be arranged for a reasonably wide range of couplings and mass scales. The primary instability in the model is the run-away of the radion vacuum expectation value. It turns out that the requirement of the radion stability, in the Higgs case, favours a Higgs boson mass below 0.26 TeV, which is consistent with the Standard Model upper bound that follows from the electroweak precision measurements. The typical radion mass is of the order of 10^{-6} eV. The radion mass can be made larger by rising the scale of fermion masses, as clearly seen in the Higgsless case. The cosmological constant may be cancelled by suitable counterterms, in such a way that the stabilization is not affected.
1704.01804
Edward Hardy
Bobby Samir Acharya, Malcolm Fairbairn, Edward Hardy
Glueball dark matter in non-standard cosmologies
28 pages, 3 figures, JHEP version
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hidden sector glueball dark matter is well motivated by string theory, compactifications of which often have extra gauge groups uncoupled to the visible sector. We study the dynamics of glueballs in theories with a period of late time primordial matter domination followed by a low final reheating temperature due to a gravitationally coupled modulus. Compared to scenarios with a high reheating temperature, the required relic abundance is possible with higher hidden sector confinement scales, and less extreme differences in the entropy densities of the hidden and visible sectors. Both of these can occur in string derived models, and relatively light moduli are helpful for obtaining viable phenomenology. We also study the effects of hidden sector gluinos. In some parts of parameter space these can be the dominant dark matter component, while in others their abundance is much smaller than that of glueballs. Finally, we show that heavy glueballs produced from energy in the hidden sector prior to matter domination can have the correct relic abundance if they are sufficiently long lived.
[ { "created": "Thu, 6 Apr 2017 12:25:48 GMT", "version": "v1" }, { "created": "Mon, 14 Aug 2017 21:53:23 GMT", "version": "v2" } ]
2017-08-16
[ [ "Acharya", "Bobby Samir", "" ], [ "Fairbairn", "Malcolm", "" ], [ "Hardy", "Edward", "" ] ]
Hidden sector glueball dark matter is well motivated by string theory, compactifications of which often have extra gauge groups uncoupled to the visible sector. We study the dynamics of glueballs in theories with a period of late time primordial matter domination followed by a low final reheating temperature due to a gravitationally coupled modulus. Compared to scenarios with a high reheating temperature, the required relic abundance is possible with higher hidden sector confinement scales, and less extreme differences in the entropy densities of the hidden and visible sectors. Both of these can occur in string derived models, and relatively light moduli are helpful for obtaining viable phenomenology. We also study the effects of hidden sector gluinos. In some parts of parameter space these can be the dominant dark matter component, while in others their abundance is much smaller than that of glueballs. Finally, we show that heavy glueballs produced from energy in the hidden sector prior to matter domination can have the correct relic abundance if they are sufficiently long lived.
hep-ph/9908486
Masaaki Kuroda
Y. Kurihara (KEK), M. Kuroda (Meiji-Gakuin University) D. Schildknecht (Bielefeld University)
High-Energy Cross Section for e^+e^- to W^+ W^- to 4 fermions + gamma
20 pages, Latex
Nucl.Phys. B565 (2000) 49-68
10.1016/S0550-3213(99)00671-9
BI-TP 99/30
hep-ph
null
A recently suggested high-energy Born-form representation of the one-loop helicity amplitudes for e^+e^- to W^+W^- is supplemented by including W^+- decay and hard-photon radiation. Results for the differential and the total cross section for e^+e^- to W^+W^- to 4 fermions + gamma are given for the high-energy region of sqrt(s) > 500 GeV.
[ { "created": "Fri, 27 Aug 1999 14:01:32 GMT", "version": "v1" }, { "created": "Tue, 12 Oct 1999 01:22:06 GMT", "version": "v2" } ]
2009-10-31
[ [ "Kurihara", "Y.", "", "KEK" ], [ "Kuroda", "M.", "", "Meiji-Gakuin University" ], [ "Schildknecht", "D.", "", "Bielefeld University" ] ]
A recently suggested high-energy Born-form representation of the one-loop helicity amplitudes for e^+e^- to W^+W^- is supplemented by including W^+- decay and hard-photon radiation. Results for the differential and the total cross section for e^+e^- to W^+W^- to 4 fermions + gamma are given for the high-energy region of sqrt(s) > 500 GeV.
2110.03977
Raghunath Sahoo
Suman Deb, Golam Sarwar, Dhananjaya Thakur, Pavish S., Raghunath Sahoo, and Jan-e Alam
Extension of Glauber-like model for Proton-Proton collisions using anisotropic and inhomogeneous density profile
Presented in LHCP-2021. To appear as PoS. Slightly modified version with corrected references
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Results from proton-proton ($pp$) collisions have routinely been used as a baseline to analyze and understand the production of QCD matter expected to be produced in nuclear collisions. But recent studies of small systems formed in $pp$ collisions at the LHC energies hint at the possibility of producing medium with collective behavior. Therefore, results from $pp$ collisions required more careful investigation to understand whether QCD matter is produced in high multiplicity $pp$ collisions. With this motivation, the Glauber model traditionally used to study the heavy-ion collision dynamics at high energy is applied here to understand the dynamics of $pp$ collisions. We have used anisotropic and inhomogeneous quark/gluon-based proton density profile, a realistic picture obtained from deep inelastic scattering results and this model explains the charged particle multiplicity distribution of $pp$ collisions at LHC energies very well. Collision geometric properties like impact parameter and mean number of binary collisions ($\langle N_{coll} \rangle$), mean number of participants ($\langle N_{part} \rangle$) at different multiplicities are determined for $pp$ collisions. We further used these collision geometric properties to estimate average charged-particle pseudorapidity density ($\langle dN_{ch}/d\eta \rangle$) and found it to be comparable with the experimental results. Knowing $\langle N_{coll} \rangle$, we have obtained nuclear modification-like factor ($R_{pp}$) in $pp$ collisions which has not been done before to the best of our knowledge.
[ { "created": "Fri, 8 Oct 2021 08:51:06 GMT", "version": "v1" }, { "created": "Wed, 27 Oct 2021 13:32:35 GMT", "version": "v2" } ]
2021-10-28
[ [ "Deb", "Suman", "" ], [ "Sarwar", "Golam", "" ], [ "Thakur", "Dhananjaya", "" ], [ "S.", "Pavish", "" ], [ "Sahoo", "Raghunath", "" ], [ "Alam", "Jan-e", "" ] ]
Results from proton-proton ($pp$) collisions have routinely been used as a baseline to analyze and understand the production of QCD matter expected to be produced in nuclear collisions. But recent studies of small systems formed in $pp$ collisions at the LHC energies hint at the possibility of producing medium with collective behavior. Therefore, results from $pp$ collisions required more careful investigation to understand whether QCD matter is produced in high multiplicity $pp$ collisions. With this motivation, the Glauber model traditionally used to study the heavy-ion collision dynamics at high energy is applied here to understand the dynamics of $pp$ collisions. We have used anisotropic and inhomogeneous quark/gluon-based proton density profile, a realistic picture obtained from deep inelastic scattering results and this model explains the charged particle multiplicity distribution of $pp$ collisions at LHC energies very well. Collision geometric properties like impact parameter and mean number of binary collisions ($\langle N_{coll} \rangle$), mean number of participants ($\langle N_{part} \rangle$) at different multiplicities are determined for $pp$ collisions. We further used these collision geometric properties to estimate average charged-particle pseudorapidity density ($\langle dN_{ch}/d\eta \rangle$) and found it to be comparable with the experimental results. Knowing $\langle N_{coll} \rangle$, we have obtained nuclear modification-like factor ($R_{pp}$) in $pp$ collisions which has not been done before to the best of our knowledge.
1702.03733
Hiroshi Okada
SangJong Lee, Takaaki Nomura, Hiroshi Okada
Radiatively Induced Neutrino Mass Model with Flavor Dependent Gauge Symmetry
18 pages, 7 figures, 2 tables; version accepted for publication in Nuclear Physics B
null
10.1016/j.nuclphysb.2018.04.010
KIAS-P17013
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a radiative seesaw model at one-loop level with a flavor dependent gauge symmetry $U(1)_{\mu-\tau}$, in which we consider bosonic dark matter. We also analyze the constraints from lepton flavor violations, muon $g-2$, relic density of dark matter, and collider physics, and carry out numerical analysis to search for allowed parameter region which satisfy all the constraints and to investigate some predictions. Furthermore we find that a simple but adhoc hypothesis induces specific two zero texture with inverse mass matrix, which provides us several predictions such as a specific pattern of Dirac CP phase.
[ { "created": "Mon, 13 Feb 2017 12:10:07 GMT", "version": "v1" }, { "created": "Wed, 18 Apr 2018 13:30:41 GMT", "version": "v2" } ]
2018-05-09
[ [ "Lee", "SangJong", "" ], [ "Nomura", "Takaaki", "" ], [ "Okada", "Hiroshi", "" ] ]
We study a radiative seesaw model at one-loop level with a flavor dependent gauge symmetry $U(1)_{\mu-\tau}$, in which we consider bosonic dark matter. We also analyze the constraints from lepton flavor violations, muon $g-2$, relic density of dark matter, and collider physics, and carry out numerical analysis to search for allowed parameter region which satisfy all the constraints and to investigate some predictions. Furthermore we find that a simple but adhoc hypothesis induces specific two zero texture with inverse mass matrix, which provides us several predictions such as a specific pattern of Dirac CP phase.
hep-ph/0311369
Giovanni Salm\`e
J. P. B. C. de Melo (Univer. Estadual-Sao Paulo), T. Frederico (ITA-Sao Paulo), E. Pace (Rome University), G. Salme` (INFN-Rome)
Electromagnetic form factor of the pion in the space- and time-like regions within the front-form dynamics
9 pages + 4 figures. To appear in Phys. Lett. B
Phys.Lett. B581 (2004) 75-81
10.1016/j.physletb.2003.11.072
INFN - 1363/03
hep-ph
null
The pion electromagnetic form factor is calculated in the space- and time-like regions from -10 $(GeV/c)^2$ up to 10 $(GeV/c)^2$, within a front-form model. The dressed photon vertex where a photon decays in a quark-antiquark pair is depicted generalizing the vector meson dominance ansatz, by means of the vector meson vertex functions. An important feature of our model is the description of the on-mass-shell vertex functions in the valence sector, for the pion and the vector mesons, through the front-form wave functions obtained within a realistic quark model. The theoretical results show an excellent agreement with the data in the space-like region, while in the time-like region the description is quite encouraging.
[ { "created": "Fri, 28 Nov 2003 15:48:52 GMT", "version": "v1" } ]
2009-11-10
[ [ "de Melo", "J. P. B. C.", "", "Univer. Estadual-Sao Paulo" ], [ "Frederico", "T.", "", "ITA-Sao Paulo" ], [ "Pace", "E.", "", "Rome University" ], [ "Salme`", "G.", "", "INFN-Rome" ] ]
The pion electromagnetic form factor is calculated in the space- and time-like regions from -10 $(GeV/c)^2$ up to 10 $(GeV/c)^2$, within a front-form model. The dressed photon vertex where a photon decays in a quark-antiquark pair is depicted generalizing the vector meson dominance ansatz, by means of the vector meson vertex functions. An important feature of our model is the description of the on-mass-shell vertex functions in the valence sector, for the pion and the vector mesons, through the front-form wave functions obtained within a realistic quark model. The theoretical results show an excellent agreement with the data in the space-like region, while in the time-like region the description is quite encouraging.
2008.04235
Wenchang Xiang
Wenchang Xiang, Mengliang Wang, Yanbing Cai, and Daicui Zhou
Solution to the Sudakov suppressed Balitsky-Kovchegov equation and its application to the HERA data
15 pages, 4 figures
null
10.1088/1674-1137/abc0cc
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analytically solve the Sudakov suppressed Balitsky-Kovchegov evolution equation with the fixed and running coupling constants in the saturation region. The analytic solution of the $S$-matrix shows the $\exp(\mathcal{O}(\eta^2))$ rapidity dependence of the solution with the fixed coupling constant is replaced by $\exp(\mathcal{O}(\eta^{3/2}))$ dependence in the smallest dipole running coupling case rather than obeying the law found in our previous publication, in which all the solutions of the next-to-leading order evolution equations comply with $\exp(\mathcal{O}(\eta))$ rapidity dependence once the QCD coupling is switched from the fixed coupling to the smallest dipole running coupling prescription. This finding indicates that the corrections of the sub-leading double logarithms in the Sudakov suppressed evolution equation are significant, which compensate part of the evolution decrease of the dipole amplitude made by running coupling effect. To test the analytic findings, we calculate the numerical solutions of the Sudakov suppressed evolution equation, the numerical results confirm the analytic outcomes. Moreover, we use the numerical solutions of the evolution equation to fit the HERA data. It shows that the Sudakove suppressed evolution equation can give good quality fit to the data.
[ { "created": "Mon, 10 Aug 2020 16:16:29 GMT", "version": "v1" } ]
2021-02-03
[ [ "Xiang", "Wenchang", "" ], [ "Wang", "Mengliang", "" ], [ "Cai", "Yanbing", "" ], [ "Zhou", "Daicui", "" ] ]
We analytically solve the Sudakov suppressed Balitsky-Kovchegov evolution equation with the fixed and running coupling constants in the saturation region. The analytic solution of the $S$-matrix shows the $\exp(\mathcal{O}(\eta^2))$ rapidity dependence of the solution with the fixed coupling constant is replaced by $\exp(\mathcal{O}(\eta^{3/2}))$ dependence in the smallest dipole running coupling case rather than obeying the law found in our previous publication, in which all the solutions of the next-to-leading order evolution equations comply with $\exp(\mathcal{O}(\eta))$ rapidity dependence once the QCD coupling is switched from the fixed coupling to the smallest dipole running coupling prescription. This finding indicates that the corrections of the sub-leading double logarithms in the Sudakov suppressed evolution equation are significant, which compensate part of the evolution decrease of the dipole amplitude made by running coupling effect. To test the analytic findings, we calculate the numerical solutions of the Sudakov suppressed evolution equation, the numerical results confirm the analytic outcomes. Moreover, we use the numerical solutions of the evolution equation to fit the HERA data. It shows that the Sudakove suppressed evolution equation can give good quality fit to the data.
1808.01437
Andreas Metz
Shohini Bhattacharya, Christopher Cocuzza, Andreas Metz
Generalized quasi parton distributions in a diquark spectator model
14 pages; version to be published in PLB
null
10.1016/j.physletb.2018.09.061
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently the concept of quasi parton distributions (quasi-PDFs) for hadrons has been proposed. Quasi-PDFs are defined through spatial correlation functions and as such can be computed numerically using quantum chromodynamics on a four-dimensional lattice. As the hadron momentum is increased, the quasi-PDFs converge to the corresponding standard PDFs that appear in factorization theorems for many high-energy scattering processes. Here we investigate this new concept in the case of generalized parton distributions (GPDs) by calculating the twist-2 vector GPDs in the scalar diquark spectator model. For infinite hadron momentum, the analytical results of the quasi-GPDs agree with those of the standard GPDs. Our main focus is to examine how well the quasi-GPDs agree with the standard GPDs for finite hadron momenta. We also study the sensitivity of the results on the parameters of the model. In general, our model calculation suggests that quasi-GPDs could be a viable tool for getting information about standard GPDs.
[ { "created": "Sat, 4 Aug 2018 06:54:44 GMT", "version": "v1" }, { "created": "Tue, 25 Sep 2018 12:35:32 GMT", "version": "v2" } ]
2018-12-26
[ [ "Bhattacharya", "Shohini", "" ], [ "Cocuzza", "Christopher", "" ], [ "Metz", "Andreas", "" ] ]
Recently the concept of quasi parton distributions (quasi-PDFs) for hadrons has been proposed. Quasi-PDFs are defined through spatial correlation functions and as such can be computed numerically using quantum chromodynamics on a four-dimensional lattice. As the hadron momentum is increased, the quasi-PDFs converge to the corresponding standard PDFs that appear in factorization theorems for many high-energy scattering processes. Here we investigate this new concept in the case of generalized parton distributions (GPDs) by calculating the twist-2 vector GPDs in the scalar diquark spectator model. For infinite hadron momentum, the analytical results of the quasi-GPDs agree with those of the standard GPDs. Our main focus is to examine how well the quasi-GPDs agree with the standard GPDs for finite hadron momenta. We also study the sensitivity of the results on the parameters of the model. In general, our model calculation suggests that quasi-GPDs could be a viable tool for getting information about standard GPDs.
hep-ph/9612414
Valery Nazaruk
V.I.Nazaruk
Cause of Disparity between the Results for the $n\bar{n}$ Transition Problem
7 pages, LaTeX
null
null
INR-1098
hep-ph nucl-th
null
We show that there is a double counting in the standard model of $n\bar{n}$ mixing in the medium, resulting in full cancellation of leading terms. The direct calculation of $n\bar{n}$ transition, annihilation is performed. For lower limit on the free-space $n\bar{n}$ oscillation time we get $\tau_{min} \sim 10^{31}y$.
[ { "created": "Thu, 19 Dec 1996 11:22:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nazaruk", "V. I.", "" ] ]
We show that there is a double counting in the standard model of $n\bar{n}$ mixing in the medium, resulting in full cancellation of leading terms. The direct calculation of $n\bar{n}$ transition, annihilation is performed. For lower limit on the free-space $n\bar{n}$ oscillation time we get $\tau_{min} \sim 10^{31}y$.
2007.08529
Martin Hoferichter
Martin Hoferichter, Javier Men\'endez, Achim Schwenk
Coherent elastic neutrino-nucleus scattering: EFT analysis and nuclear responses
28 pages, 11 figures; journal version
Phys. Rev. D 102, 074018 (2020)
10.1103/PhysRevD.102.074018
INT-PUB-20-026
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cross section for coherent elastic neutrino-nucleus scattering (CE$\nu$NS) depends on the response of the target nucleus to the external current, in the Standard Model (SM) mediated by the exchange of a $Z$ boson. This is typically subsumed into an object called the weak form factor of the nucleus. Here, we provide results for this form factor calculated using the large-scale nuclear shell model for a wide range of nuclei of relevance for current CE$\nu$NS experiments, including cesium, iodine, argon, fluorine, sodium, germanium, and xenon. In addition, we provide the responses needed to capture the axial-vector part of the cross section, which does not scale coherently with the number of neutrons, but may become relevant for the SM prediction of CE$\nu$NS on target nuclei with nonzero spin. We then generalize the formalism allowing for contributions beyond the SM. In particular, we stress that in this case, even for vector and axial-vector operators, the standard weak form factor does not apply anymore, but needs to be replaced by the appropriate combination of the underlying nuclear structure factors. We provide the corresponding expressions for vector, axial-vector, but also (pseudo-)scalar, tensor, and dipole effective operators, including two-body-current effects as predicted from chiral effective field theory. Finally, we update the spin-dependent structure factors for dark matter scattering off nuclei according to our improved treatment of the axial-vector responses.
[ { "created": "Thu, 16 Jul 2020 18:00:01 GMT", "version": "v1" }, { "created": "Fri, 23 Oct 2020 14:36:17 GMT", "version": "v2" } ]
2020-10-26
[ [ "Hoferichter", "Martin", "" ], [ "Menéndez", "Javier", "" ], [ "Schwenk", "Achim", "" ] ]
The cross section for coherent elastic neutrino-nucleus scattering (CE$\nu$NS) depends on the response of the target nucleus to the external current, in the Standard Model (SM) mediated by the exchange of a $Z$ boson. This is typically subsumed into an object called the weak form factor of the nucleus. Here, we provide results for this form factor calculated using the large-scale nuclear shell model for a wide range of nuclei of relevance for current CE$\nu$NS experiments, including cesium, iodine, argon, fluorine, sodium, germanium, and xenon. In addition, we provide the responses needed to capture the axial-vector part of the cross section, which does not scale coherently with the number of neutrons, but may become relevant for the SM prediction of CE$\nu$NS on target nuclei with nonzero spin. We then generalize the formalism allowing for contributions beyond the SM. In particular, we stress that in this case, even for vector and axial-vector operators, the standard weak form factor does not apply anymore, but needs to be replaced by the appropriate combination of the underlying nuclear structure factors. We provide the corresponding expressions for vector, axial-vector, but also (pseudo-)scalar, tensor, and dipole effective operators, including two-body-current effects as predicted from chiral effective field theory. Finally, we update the spin-dependent structure factors for dark matter scattering off nuclei according to our improved treatment of the axial-vector responses.
1209.4803
Priyotosh Bandyopadhyay
Priyotosh Bandyopadhyay, Eung Jin Chun, Hiroshi Okada and Jong-Chul Park
Higgs Signatures in Inverse Seesaw Model at the LHC
25 pages, 10 figures and 10 tables
null
10.1007/JHEP01(2013)079
KIAS-P12026; HIP-2012-13/TH
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the inverse seesaw mechanism where the spontaneously broken B-L symmetry induces tiny B-L violating Majorana masses for right-handed neutrinos, non-standard Higgs signatures can arise due to a possible Higgs doublet and singlet mixing and/or Higgs boson decays to a left- and right-handed neutrino. This leads to a remarkable feature of hadronically quiet di-lepton final states which can exhibit, in particular, lepton flavour violating signatures coming from flavour-dependent neutrino Yukawa couplings. In this process, one lepton coming from the right-handed decay could be soft enough can be missed by the trigger level cuts of CMS and ATLAS for the di-lepton plus missing energy signature. The prospects of such a signature are investigated for 8 TeV and 14 TeV center of mass energy of the LHC, taking the maximum value of the allowed neutrino Yukawa coupling and the right-handed neutrino mass of 100 GeV. A PYTHIA level simulation shows that the integrated luminosity of 10--20/fb and 1.6/fb for 8 TeV is required to observe the inclusive leptonic and lepton flavour violating signatures, respectively. For 14 TeV, the reach is more and a larger parameter space of the inverse seesaw model can be probed.
[ { "created": "Fri, 21 Sep 2012 12:45:38 GMT", "version": "v1" } ]
2015-06-11
[ [ "Bandyopadhyay", "Priyotosh", "" ], [ "Chun", "Eung Jin", "" ], [ "Okada", "Hiroshi", "" ], [ "Park", "Jong-Chul", "" ] ]
In the inverse seesaw mechanism where the spontaneously broken B-L symmetry induces tiny B-L violating Majorana masses for right-handed neutrinos, non-standard Higgs signatures can arise due to a possible Higgs doublet and singlet mixing and/or Higgs boson decays to a left- and right-handed neutrino. This leads to a remarkable feature of hadronically quiet di-lepton final states which can exhibit, in particular, lepton flavour violating signatures coming from flavour-dependent neutrino Yukawa couplings. In this process, one lepton coming from the right-handed decay could be soft enough can be missed by the trigger level cuts of CMS and ATLAS for the di-lepton plus missing energy signature. The prospects of such a signature are investigated for 8 TeV and 14 TeV center of mass energy of the LHC, taking the maximum value of the allowed neutrino Yukawa coupling and the right-handed neutrino mass of 100 GeV. A PYTHIA level simulation shows that the integrated luminosity of 10--20/fb and 1.6/fb for 8 TeV is required to observe the inclusive leptonic and lepton flavour violating signatures, respectively. For 14 TeV, the reach is more and a larger parameter space of the inverse seesaw model can be probed.
1511.04379
Sophia Borowka
S. Borowka
Calculation of multi-scale, multi-loop integrals using SecDec 3
5 pages, proceedings contribution to the XXXIX international conference of theoretical physics "Matter to the deepest 2015"
null
10.5506/APhysPolB.46.2137
ZU-TH 37/15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In these proceedings the publicly available program SecDec is briefly described. Its main virtues and new features are summarized, including suggestions for an optimal usage of the program.
[ { "created": "Fri, 13 Nov 2015 17:37:21 GMT", "version": "v1" } ]
2016-01-20
[ [ "Borowka", "S.", "" ] ]
In these proceedings the publicly available program SecDec is briefly described. Its main virtues and new features are summarized, including suggestions for an optimal usage of the program.
2009.02205
Benjamin Nachman
Kees Benkendorfer, Luc Le Pottier, and Benjamin Nachman
Simulation-Assisted Decorrelation for Resonant Anomaly Detection
17 pages, 7 figures
Phys. Rev. D 104, 035003 (2021)
10.1103/PhysRevD.104.035003
null
hep-ph hep-ex physics.data-an stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A growing number of weak- and unsupervised machine learning approaches to anomaly detection are being proposed to significantly extend the search program at the Large Hadron Collider and elsewhere. One of the prototypical examples for these methods is the search for resonant new physics, where a bump hunt can be performed in an invariant mass spectrum. A significant challenge to methods that rely entirely on data is that they are susceptible to sculpting artificial bumps from the dependence of the machine learning classifier on the invariant mass. We explore two solutions to this challenge by minimally incorporating simulation into the learning. In particular, we study the robustness of Simulation Assisted Likelihood-free Anomaly Detection (SALAD) to correlations between the classifier and the invariant mass. Next, we propose a new approach that only uses the simulation for decorrelation but the Classification without Labels (CWoLa) approach for achieving signal sensitivity. Both methods are compared using a full background fit analysis on simulated data from the LHC Olympics and are robust to correlations in the data.
[ { "created": "Fri, 4 Sep 2020 14:02:15 GMT", "version": "v1" } ]
2021-08-11
[ [ "Benkendorfer", "Kees", "" ], [ "Pottier", "Luc Le", "" ], [ "Nachman", "Benjamin", "" ] ]
A growing number of weak- and unsupervised machine learning approaches to anomaly detection are being proposed to significantly extend the search program at the Large Hadron Collider and elsewhere. One of the prototypical examples for these methods is the search for resonant new physics, where a bump hunt can be performed in an invariant mass spectrum. A significant challenge to methods that rely entirely on data is that they are susceptible to sculpting artificial bumps from the dependence of the machine learning classifier on the invariant mass. We explore two solutions to this challenge by minimally incorporating simulation into the learning. In particular, we study the robustness of Simulation Assisted Likelihood-free Anomaly Detection (SALAD) to correlations between the classifier and the invariant mass. Next, we propose a new approach that only uses the simulation for decorrelation but the Classification without Labels (CWoLa) approach for achieving signal sensitivity. Both methods are compared using a full background fit analysis on simulated data from the LHC Olympics and are robust to correlations in the data.
hep-ph/9509327
Raymond Volkas
R. Foot, M. J. Thomson and R. R. Volkas
Large neutrino asymmetries from neutrino oscillations
12 pages, LaTeX, one figure
Phys.Rev.D53:5349-5353,1996
10.1103/PhysRevD.53.R5349
UM-P-95/90
hep-ph astro-ph
null
We re-examine neutrino oscillations in the early universe. Contrary to previous studies, we show that large neutrino asymmetries can arise due to oscillations between ordinary neutrinos and sterile neutrinos. This means that the Big Bang Nucleosynthesis (BBN) bounds on the mass and mixing of ordinary neutrinos with sterile neutrinos can be evaded. Also, it is possible that the neutrino asymmetries can be large (i.e. $\stackrel{>}{\sim} 10\%$), and hence have a significant effect on BBN through nuclear reaction rates.
[ { "created": "Tue, 19 Sep 1995 06:36:41 GMT", "version": "v1" } ]
2011-02-24
[ [ "Foot", "R.", "" ], [ "Thomson", "M. J.", "" ], [ "Volkas", "R. R.", "" ] ]
We re-examine neutrino oscillations in the early universe. Contrary to previous studies, we show that large neutrino asymmetries can arise due to oscillations between ordinary neutrinos and sterile neutrinos. This means that the Big Bang Nucleosynthesis (BBN) bounds on the mass and mixing of ordinary neutrinos with sterile neutrinos can be evaded. Also, it is possible that the neutrino asymmetries can be large (i.e. $\stackrel{>}{\sim} 10\%$), and hence have a significant effect on BBN through nuclear reaction rates.
hep-ph/0510084
Kuraev Eduard
V. Bytev, E. Bartos, M.V. Galynskii, E.A. Kuraev
Radiative corrections to chiral amplitudes in quasiperipheral kinematics
25 pages, 6 figures
J.Exp.Theor.Phys. 103 (2006) 224-240
10.1134/S1063776106080061
null
hep-ph
null
Chiral amplitudes for two jets processes in quasi-peripheral kinematics are calculated at the Born and one loop correction level. The amplitudes of subprocesses describing interaction of virtual and real photon with creation of a charged fermion pair for various chiral states are considered in details. Similar results are presented for Compton subprocess with virtual photon. Contribution of emission of virtual, soft, and hard real additional photons are taken into account explicitly. The relevant cross sections expressed in terms of impact factors are in agreement with structure function approach in the leading logarithmical approximation. Contributions of the next to leading terms are presented in an analytical form. Accuracy estimation is discussed.
[ { "created": "Fri, 7 Oct 2005 07:51:34 GMT", "version": "v1" }, { "created": "Tue, 21 Mar 2006 13:04:20 GMT", "version": "v2" } ]
2016-09-06
[ [ "Bytev", "V.", "" ], [ "Bartos", "E.", "" ], [ "Galynskii", "M. V.", "" ], [ "Kuraev", "E. A.", "" ] ]
Chiral amplitudes for two jets processes in quasi-peripheral kinematics are calculated at the Born and one loop correction level. The amplitudes of subprocesses describing interaction of virtual and real photon with creation of a charged fermion pair for various chiral states are considered in details. Similar results are presented for Compton subprocess with virtual photon. Contribution of emission of virtual, soft, and hard real additional photons are taken into account explicitly. The relevant cross sections expressed in terms of impact factors are in agreement with structure function approach in the leading logarithmical approximation. Contributions of the next to leading terms are presented in an analytical form. Accuracy estimation is discussed.
0901.0613
Jackson Wu
We-Fu Chang, John N. Ng, Jackson M. S. Wu
Exploring Non-Supersymmetric New Physics in Polarized M\o{}ller Scattering
v2: 25 pages, 7 figures. Typos fixed, clarifications added, presentation of plots improved, title slightly changed. To be published in PRD
Phys.Rev.D79:055016,2009
10.1103/PhysRevD.79.055016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study in an effective operator approach how the effects of new physics from various scenarios that contain an extra $Z'$ neutral gauge boson or doubly charged scalars, can affect and thus be tested by the precision polarized M\o{}ller scattering experiments. We give Wilson coefficients for various classes of generic models, and we deduce constraints on the parameter space of the relevant coupling constants or mixing angles from the results of the SLAC E158 experiment where applicable. We give also constraints projected from the upcoming 1 ppb JLAB experiment. In the scenario where the extra $Z'$ is light ($M_{Z'} \ll M_W$), we obtain further constraints on the parameter space using the BNL $g-2$ result where it is useful. We find that the BNL deviation from the Standard Model cannot be attributed to a light extra $Z'$ neutral gauge boson.
[ { "created": "Tue, 6 Jan 2009 09:37:35 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 2009 16:24:59 GMT", "version": "v2" } ]
2009-11-13
[ [ "Chang", "We-Fu", "" ], [ "Ng", "John N.", "" ], [ "Wu", "Jackson M. S.", "" ] ]
We study in an effective operator approach how the effects of new physics from various scenarios that contain an extra $Z'$ neutral gauge boson or doubly charged scalars, can affect and thus be tested by the precision polarized M\o{}ller scattering experiments. We give Wilson coefficients for various classes of generic models, and we deduce constraints on the parameter space of the relevant coupling constants or mixing angles from the results of the SLAC E158 experiment where applicable. We give also constraints projected from the upcoming 1 ppb JLAB experiment. In the scenario where the extra $Z'$ is light ($M_{Z'} \ll M_W$), we obtain further constraints on the parameter space using the BNL $g-2$ result where it is useful. We find that the BNL deviation from the Standard Model cannot be attributed to a light extra $Z'$ neutral gauge boson.
hep-ph/0510270
Sebastian Sapeta
S.Sapeta
Diffraction at Tevatron and LHC in the Miettinen-Pumplin model
6 pages, 3 figures; Talk presented at the XLV Cracow School of Theoretical Physics, Zakopane, Poland, June 3-12, 2005
Acta Phys.Polon. B36 (2005) 3689-3696
null
null
hep-ph
null
The process of soft diffractive dissociation in hadronic collisions is discussed in the framework of the Miettinen-Pumplin model. A good description of the data in the ISR-Tevatron energy range is found. Predictions for the total, elastic and single diffractive cross sections for the LHC are also presented. The total cross section is expected to be 15% smaller than that given by Donnachie and Landshoff in the model with soft pomeron. The diffractive cross section remains constant in the Tevatron-LHC energy range.
[ { "created": "Thu, 20 Oct 2005 15:01:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sapeta", "S.", "" ] ]
The process of soft diffractive dissociation in hadronic collisions is discussed in the framework of the Miettinen-Pumplin model. A good description of the data in the ISR-Tevatron energy range is found. Predictions for the total, elastic and single diffractive cross sections for the LHC are also presented. The total cross section is expected to be 15% smaller than that given by Donnachie and Landshoff in the model with soft pomeron. The diffractive cross section remains constant in the Tevatron-LHC energy range.
1504.03799
Weizhen Deng
Yi-Long Luan, Xiao-Lin Chen and Wei-Zhen Deng
Meson Electro-Magnetic Form Factors in an Extended Nambu--Jona-Lasinio model including Heavy Quark Flavors
null
Chinese Physics C Vol. 39, No. 11 (2015) 113103
10.1088/1674-1137/39/11/113103
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on an extended NJL model including heavy quark flavors, we calculate the form factors of pseudo-scalar and vector mesons. After take into account of the vector-meson-dominance effect which introduce a form factor correction to the quark vector coupling vertices, the form factors and electric radii of $\pi^+$ and $K^+$ of pseudo-scalar meson in light flavor sector fit the experimental data well. Also the magnetic moments of light vector meson $\rho^+$ and $K^{*+}$ are comparable with other theoretical calculation. The form factors in light-heavy flavor sector are presented to confront with future experiments or theoretical calculations.
[ { "created": "Wed, 15 Apr 2015 07:19:39 GMT", "version": "v1" }, { "created": "Sun, 21 Jun 2015 11:08:33 GMT", "version": "v2" } ]
2015-09-24
[ [ "Luan", "Yi-Long", "" ], [ "Chen", "Xiao-Lin", "" ], [ "Deng", "Wei-Zhen", "" ] ]
Based on an extended NJL model including heavy quark flavors, we calculate the form factors of pseudo-scalar and vector mesons. After take into account of the vector-meson-dominance effect which introduce a form factor correction to the quark vector coupling vertices, the form factors and electric radii of $\pi^+$ and $K^+$ of pseudo-scalar meson in light flavor sector fit the experimental data well. Also the magnetic moments of light vector meson $\rho^+$ and $K^{*+}$ are comparable with other theoretical calculation. The form factors in light-heavy flavor sector are presented to confront with future experiments or theoretical calculations.
2208.03790
Ephraim Fischbach
Ephraim Fischbach, Dennis E. Krause, Quan Le Thien, and Carol Scarlett
Implications of Recent KATRIN Results for Lower-Limits on Neutrino Masses
5 pages, 6 figures, Revtex
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Recently announced results from the KATRIN collaboration imply an upper bound on the effective electron anti-neutrino mass $m_{\nu_{e}}$, $m_{\nu_{e}}< 0.8~{\rm eV}/c^{2}$. Here we explore the implications of combining the KATRIN upper bound using a previously inferred lower bound on the smallest neutrino mass state, $m_{i,{\rm min}}\gtrsim 0.4~{\rm eV}/c^{2}$ implied by the stability of white dwarfs and neutron stars in the presence of long-range many-body neutrino-exchange forces. By combining a revised lower bound estimate with the expected final upper bound from KATRIN, we find that the available parameter space for $m_{\nu_{e}}$ may be closed completely within the next few years. We then extend the argument when a single light sterile neutrino flavor is present to set a lower mass limit on sterile neutrinos.
[ { "created": "Sun, 7 Aug 2022 19:06:19 GMT", "version": "v1" } ]
2022-08-09
[ [ "Fischbach", "Ephraim", "" ], [ "Krause", "Dennis E.", "" ], [ "Thien", "Quan Le", "" ], [ "Scarlett", "Carol", "" ] ]
Recently announced results from the KATRIN collaboration imply an upper bound on the effective electron anti-neutrino mass $m_{\nu_{e}}$, $m_{\nu_{e}}< 0.8~{\rm eV}/c^{2}$. Here we explore the implications of combining the KATRIN upper bound using a previously inferred lower bound on the smallest neutrino mass state, $m_{i,{\rm min}}\gtrsim 0.4~{\rm eV}/c^{2}$ implied by the stability of white dwarfs and neutron stars in the presence of long-range many-body neutrino-exchange forces. By combining a revised lower bound estimate with the expected final upper bound from KATRIN, we find that the available parameter space for $m_{\nu_{e}}$ may be closed completely within the next few years. We then extend the argument when a single light sterile neutrino flavor is present to set a lower mass limit on sterile neutrinos.
hep-ph/0407306
Thomas D. Cohen
Thomas D. Cohen
Large Nc Continuum Reduction and the Thermodynamics of QCD
null
Phys.Rev.Lett. 93 (2004) 201601
10.1103/PhysRevLett.93.201601
null
hep-ph hep-lat nucl-th
null
It is noted that if large Nc continuum reduction applies to an observable, then that observable is independent of temperature for all temperatures below some critical value. This fact, plus the fact that mesons and glueballs are weakly interacting at large Nc is used as the basis for a derivation of large Nc continuum reduction for the chiral condensate. The structure of this derivation is quite general and can be extended to a wide class of observables.
[ { "created": "Tue, 27 Jul 2004 13:43:31 GMT", "version": "v1" } ]
2009-11-10
[ [ "Cohen", "Thomas D.", "" ] ]
It is noted that if large Nc continuum reduction applies to an observable, then that observable is independent of temperature for all temperatures below some critical value. This fact, plus the fact that mesons and glueballs are weakly interacting at large Nc is used as the basis for a derivation of large Nc continuum reduction for the chiral condensate. The structure of this derivation is quite general and can be extended to a wide class of observables.
hep-ph/9708457
Zhi Gang Yu
Guang-jiong Ni and Haibin Wang
New Regularization-Renormalization Method in Quantum Electrodynamics and Qualitative Calculation on Lamb Shift
9 pages, no figures
null
null
null
hep-ph
null
A simple but effective method for regularization-renormalization (R-R) is proposed for handling the Feynman diagram integral (FDI) at one loop level in quantum electrodynamics (QED). The divergence is substituted by some constants to be fixed via experiments. So no counter term, no bare parameter and no arbitrary running mass scale is involved. Then the Lamb Shift in Hydrogen atom can be calculated qualitatively and simply as $\Delta E(2S_{1/2})- \Delta E(2P_{1/2})=996.7 MHz$ versus the experimental value $1057.85 MHz$.
[ { "created": "Mon, 25 Aug 1997 22:51:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ni", "Guang-jiong", "" ], [ "Wang", "Haibin", "" ] ]
A simple but effective method for regularization-renormalization (R-R) is proposed for handling the Feynman diagram integral (FDI) at one loop level in quantum electrodynamics (QED). The divergence is substituted by some constants to be fixed via experiments. So no counter term, no bare parameter and no arbitrary running mass scale is involved. Then the Lamb Shift in Hydrogen atom can be calculated qualitatively and simply as $\Delta E(2S_{1/2})- \Delta E(2P_{1/2})=996.7 MHz$ versus the experimental value $1057.85 MHz$.
0810.5667
Oliver Fochler
Oliver Fochler, Andrej El, Zhe Xu and Carsten Greiner
QCD plasma equilibration, elliptic flow and jet-quenching - phenomena of common origin
Proc. 24th Winter Workshop on Nuclear Dynamics (2008), South Padre, Texas, USA
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fast thermalization, a subsequent strong buildup of elliptic flow of QCD matter and jet-quenching as found at the Relativistic Heavy Ion Collider (RHIC) are understood as the consequence of perturbative QCD (pQCD) interactions within the 3+1 dimensional parton cascade BAMPS. The main contributions stem from pQCD inspired bremsstrahlung. Comparisons to Au+Au data of the flow parameter v_2 as a function of participation number as well as the gluonic contribution to the nuclear modification factor R_AA for most central collisions are given. Also the shear viscosity to entropy ratio is dynamically extracted, which lies in the range of 0.08-0.15, depending on the chosen coupling constant.
[ { "created": "Fri, 31 Oct 2008 11:53:30 GMT", "version": "v1" } ]
2008-11-03
[ [ "Fochler", "Oliver", "" ], [ "El", "Andrej", "" ], [ "Xu", "Zhe", "" ], [ "Greiner", "Carsten", "" ] ]
Fast thermalization, a subsequent strong buildup of elliptic flow of QCD matter and jet-quenching as found at the Relativistic Heavy Ion Collider (RHIC) are understood as the consequence of perturbative QCD (pQCD) interactions within the 3+1 dimensional parton cascade BAMPS. The main contributions stem from pQCD inspired bremsstrahlung. Comparisons to Au+Au data of the flow parameter v_2 as a function of participation number as well as the gluonic contribution to the nuclear modification factor R_AA for most central collisions are given. Also the shear viscosity to entropy ratio is dynamically extracted, which lies in the range of 0.08-0.15, depending on the chosen coupling constant.
1403.0415
Sergei Nedelko
Sergei N. Nedelko, Vladimir E. Voronin
Domain wall network as QCD vacuum and the chromomagnetic trap formation under extreme conditions
20 pages, 10 figures
null
10.1140/epja/i2015-15045-8
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ensemble of Euclidean gluon field configurations represented by the domain wall network is considered. A single domain wall is given by the sine-Gordon kink for the angle between chromomagnetic and chromoelectric components of the gauge field. The domain wall separates the regions with self-dual and anti-self-dual fields. The network of the domain wall defects is introduced as a combination of multiplicative and additive superpositions of kinks. The character of the spectrum and eigenmodes of color-charged fluctuations in the presence of the domain wall network is discussed. The concept of the confinement-deconfinement transition in terms of the ensemble of domain wall networks is outlined. Conditions for the formation of thick domain wall junction during heavy ion collisions are discussed, and the spectrum of color charged quasiparticles inside the trap is evaluated. An important observation is the existence of the critical size $L_c$ of the trap stable against gluon tachyonic modes, which means that deconfinement can occur only in a finite region of space-time in principle. The size $L_c$ is related to the value of gluon condensate $\langle g^2F^2\rangle$.
[ { "created": "Mon, 3 Mar 2014 12:48:14 GMT", "version": "v1" } ]
2015-06-18
[ [ "Nedelko", "Sergei N.", "" ], [ "Voronin", "Vladimir E.", "" ] ]
The ensemble of Euclidean gluon field configurations represented by the domain wall network is considered. A single domain wall is given by the sine-Gordon kink for the angle between chromomagnetic and chromoelectric components of the gauge field. The domain wall separates the regions with self-dual and anti-self-dual fields. The network of the domain wall defects is introduced as a combination of multiplicative and additive superpositions of kinks. The character of the spectrum and eigenmodes of color-charged fluctuations in the presence of the domain wall network is discussed. The concept of the confinement-deconfinement transition in terms of the ensemble of domain wall networks is outlined. Conditions for the formation of thick domain wall junction during heavy ion collisions are discussed, and the spectrum of color charged quasiparticles inside the trap is evaluated. An important observation is the existence of the critical size $L_c$ of the trap stable against gluon tachyonic modes, which means that deconfinement can occur only in a finite region of space-time in principle. The size $L_c$ is related to the value of gluon condensate $\langle g^2F^2\rangle$.
2308.05944
Victoria Puyam
Victoria Puyam and N. Nimai Singh
$A_{5}$ symmetry and deviation from Golden Ratio mixing with charged lepton flavor violation
26 figures and 4 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A neutrino mass model that can satisfy the exact golden ratio mixing is constructed using $A_{5}$ discrete symmetry group. The deviation from the golden ratio mixing is studied by considering the contribution from the charged lepton sector in a linear seesaw framework. A definite pattern of charged lepton mass matrix predicted by the model controls the leptonic mixing angles. By taking the observed $\theta_{13}$ as the input value, we can obtain the values of all the mixing angles and Dirac CP-violating phase within the current experimental bounds. The model predicts that only the normal neutrino mass ordering is consistent with the current oscillation data. We also study the charged lepton flavor violation (cLFV) process such as $\mu \rightarrow e +\gamma$ and $\tau \rightarrow e +\gamma$ and neutrinoless double beta decay parameter $m_{\beta \beta}$. The present neutrino mass model can explain the current and future sensitivity of the cLFV processes and the present sensitivity of neutrinoless double beta decay parameter when the masses of quasi-Dirac neutrinos are in the TeV range.
[ { "created": "Fri, 11 Aug 2023 05:37:13 GMT", "version": "v1" }, { "created": "Sun, 3 Mar 2024 11:02:32 GMT", "version": "v2" } ]
2024-03-05
[ [ "Puyam", "Victoria", "" ], [ "Singh", "N. Nimai", "" ] ]
A neutrino mass model that can satisfy the exact golden ratio mixing is constructed using $A_{5}$ discrete symmetry group. The deviation from the golden ratio mixing is studied by considering the contribution from the charged lepton sector in a linear seesaw framework. A definite pattern of charged lepton mass matrix predicted by the model controls the leptonic mixing angles. By taking the observed $\theta_{13}$ as the input value, we can obtain the values of all the mixing angles and Dirac CP-violating phase within the current experimental bounds. The model predicts that only the normal neutrino mass ordering is consistent with the current oscillation data. We also study the charged lepton flavor violation (cLFV) process such as $\mu \rightarrow e +\gamma$ and $\tau \rightarrow e +\gamma$ and neutrinoless double beta decay parameter $m_{\beta \beta}$. The present neutrino mass model can explain the current and future sensitivity of the cLFV processes and the present sensitivity of neutrinoless double beta decay parameter when the masses of quasi-Dirac neutrinos are in the TeV range.
hep-ph/9811325
James Wells
James D. Wells (CERN), Alexander Moiseev (NASA), Jonathan F. Ormes (NASA)
Illuminating dark matter and primordial black holes with interstellar antiprotons
18 pages, 3 figures
Astrophys.J. 518 (1999) 570
10.1086/307325
CERN-TH/98-362
hep-ph astro-ph
null
Interstellar antiproton fluxes can arise from dark matter annihilating or decaying into quarks or gluons that subsequently fragment into antiprotons. Evaporation of primordial black holes also can produce a significant antiproton cosmic-ray flux. Since the background of secondary antiprotons from spallation has an interstellar energy spectrum that peaks at $\sim 2\gev$ and falls rapidly for energies below this, low-energy measurements of cosmic antiprotons are useful in the search for exotic antiproton sources. However, measurement of the flux near the earth is challenged by significant uncertainties from the effects of the solar wind. We suggest evading this problem and more effectively probing dark-matter signals by placing an antiproton spectrometer aboard an interstellar probe currently under discussion. We address the experimental challenges of a light, low-power-consuming detector, and present an initial design of such an instrument. This experimental effort could significantly increase our ability to detect, and have confidence in, a signal of exotic, nonstandard antiproton sources. Furthermore, solar modulation effects in the heliosphere would be better quantified and understood by comparing results to inverse modulated data derived from existing balloon and space-based detectors near the earth.
[ { "created": "Fri, 13 Nov 1998 21:06:32 GMT", "version": "v1" } ]
2009-10-31
[ [ "Wells", "James D.", "", "CERN" ], [ "Moiseev", "Alexander", "", "NASA" ], [ "Ormes", "Jonathan F.", "", "NASA" ] ]
Interstellar antiproton fluxes can arise from dark matter annihilating or decaying into quarks or gluons that subsequently fragment into antiprotons. Evaporation of primordial black holes also can produce a significant antiproton cosmic-ray flux. Since the background of secondary antiprotons from spallation has an interstellar energy spectrum that peaks at $\sim 2\gev$ and falls rapidly for energies below this, low-energy measurements of cosmic antiprotons are useful in the search for exotic antiproton sources. However, measurement of the flux near the earth is challenged by significant uncertainties from the effects of the solar wind. We suggest evading this problem and more effectively probing dark-matter signals by placing an antiproton spectrometer aboard an interstellar probe currently under discussion. We address the experimental challenges of a light, low-power-consuming detector, and present an initial design of such an instrument. This experimental effort could significantly increase our ability to detect, and have confidence in, a signal of exotic, nonstandard antiproton sources. Furthermore, solar modulation effects in the heliosphere would be better quantified and understood by comparing results to inverse modulated data derived from existing balloon and space-based detectors near the earth.
hep-ph/9407402
null
B. Moussallam
Chiral Sum-Rules for ${\cal L}^{WZ}_{(6)}$ Parameters and Application to $\pi^0,\eta,\eta'$ Decays
An important sign error was corrected and the paper has somewhat expanded
Phys.Rev. D51 (1995) 4939-4949
10.1103/PhysRevD.51.4939
null
hep-ph
null
The chiral expansion of the low energy processes $\pi^0\to\gamma\gamma$ and $\eta\to\gamma\gamma$ is reconsidered with particular emphasis on the question of the evaluation of the two low-energy parameters from ${\cal L}^{WZ}_{(6)}$ which are involved at chiral order six. It is shown how extensive use of sum-rules and saturation with resonances as well as constraints from asymptotic QCD effectively determine their values. Predictions for the widths are presented for both standard and non-standard values of the quark mass ratio $m_s/{\hat m}$. A precise relation is established between the usual phenomenological $\eta-\eta'$ mixing parameters and those of the chiral expansion. The large size of the chiral correction to the $\eta$ decay can be understood on the basis of a simple counting rule: $O(1/N_c)\sim\ O(m_q)$. It is shown how this counting rule eventually allows one to include the $\eta'$ into the effective lagrangian in a consistent and systematic way.
[ { "created": "Fri, 29 Jul 1994 16:32:01 GMT", "version": "v1" }, { "created": "Thu, 23 Mar 1995 13:44:26 GMT", "version": "v2" } ]
2009-10-28
[ [ "Moussallam", "B.", "" ] ]
The chiral expansion of the low energy processes $\pi^0\to\gamma\gamma$ and $\eta\to\gamma\gamma$ is reconsidered with particular emphasis on the question of the evaluation of the two low-energy parameters from ${\cal L}^{WZ}_{(6)}$ which are involved at chiral order six. It is shown how extensive use of sum-rules and saturation with resonances as well as constraints from asymptotic QCD effectively determine their values. Predictions for the widths are presented for both standard and non-standard values of the quark mass ratio $m_s/{\hat m}$. A precise relation is established between the usual phenomenological $\eta-\eta'$ mixing parameters and those of the chiral expansion. The large size of the chiral correction to the $\eta$ decay can be understood on the basis of a simple counting rule: $O(1/N_c)\sim\ O(m_q)$. It is shown how this counting rule eventually allows one to include the $\eta'$ into the effective lagrangian in a consistent and systematic way.
0807.0394
Alfredo Valcarce
A. Valcarce, J. Vijande, P. Gonzalez, H. Garcilazo
Hadron physics: a quark-model analysis
Talk given at the 6th International Conference on Perspectives in Hadronic Physics, Trieste, Italy, 12-16 May 2008
AIPConf.Proc.1056:47-54,2008
10.1063/1.3013079
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss recent results on heavy and light baryon spectroscopy
[ { "created": "Wed, 2 Jul 2008 16:27:52 GMT", "version": "v1" } ]
2008-11-26
[ [ "Valcarce", "A.", "" ], [ "Vijande", "J.", "" ], [ "Gonzalez", "P.", "" ], [ "Garcilazo", "H.", "" ] ]
We discuss recent results on heavy and light baryon spectroscopy
hep-ph/9906547
Aude Gehrmann
A. Gehrmann-De Ridder (Karlsruhe University,TTP & DESY)
Deep-inelastic Electron-Photon Scattering at High Q^2 : Neutral and Charged Current Reactions
Talk given at the International Conference on the Structure and Interactions of the Photon, PHOTON 99, Freiburg im Breisgau, Germany, May 23-27, 1999. To be published in the Proceedings. 6 pages, 6 postscript figures. The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ttp99/ttp99-30/ or via www at http://www-ttp.physik.uni-karlsruhe.de/Preprints/
Nucl.Phys.Proc.Suppl. 82 (2000) 385-390
10.1016/S0920-5632(00)00182-1
TTP99-30
hep-ph
null
We present the results of a calculation of deep inelastic electron-photon scattering at a linear collider for very high virtuality of the intermediate gauge boson up to NLO in perturbative QCD. The real photon is produced unpolarized via the Compton back scattering of laser light of the incoming beam. For $Q^2$ values close to the masses squared of the Z and W gauge bosons, the deep inelastic electron-photon scattering process receives important contributions not only from virtual photon exchange but also from the exchange of a Z-boson and a W-boson. We find that the total cross section for center of mass energies above $500 \rm{GeV}$ is at least of ${\cal O}(pb)$ and has an important charged current contribution.
[ { "created": "Wed, 30 Jun 1999 12:11:57 GMT", "version": "v1" } ]
2009-10-31
[ [ "Ridder", "A. Gehrmann-De", "", "Karlsruhe University,TTP & DESY" ] ]
We present the results of a calculation of deep inelastic electron-photon scattering at a linear collider for very high virtuality of the intermediate gauge boson up to NLO in perturbative QCD. The real photon is produced unpolarized via the Compton back scattering of laser light of the incoming beam. For $Q^2$ values close to the masses squared of the Z and W gauge bosons, the deep inelastic electron-photon scattering process receives important contributions not only from virtual photon exchange but also from the exchange of a Z-boson and a W-boson. We find that the total cross section for center of mass energies above $500 \rm{GeV}$ is at least of ${\cal O}(pb)$ and has an important charged current contribution.
1606.00775
Ivan Ni\v{s}and\v{z}i\'c
Simon Bra{\ss}, Gudrun Hiller and Ivan Nisandzic
Zooming in on $B\to K^\ast \ell\ell$ decays at low recoil
18 pages, v2: references and clarifications added, conclusions unchanged, matches published version
Eur.Phys.J. C77 (2017) no.1, 16
10.1140/epjc/s10052-016-4576-9
DO-TH 16/06, SI-HEP-2016-11
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse $B\to K^\ast \ell\ell$ decays in the region of low hadronic recoil, where an operator product expansion (OPE) in $1/m_b$ applies. Using a local model for charm contributions based on $e^+ e^- \to hadrons$ against the OPE provides a data-driven method to access the limitations to the OPE's accuracy related to binnings in the dilepton mass. Model-independent fits to $B\to K^\ast \mu \mu $ low recoil angular observables exhibit presently only small sensitivity to different charm models. They give similar results as the fits based on the OPE, and are in agreement with the standard model, but leave also room for new physics. Measurements with resolution small enough to probe charm resonances would be desirable.
[ { "created": "Thu, 2 Jun 2016 17:36:08 GMT", "version": "v1" }, { "created": "Wed, 25 Jan 2017 13:11:28 GMT", "version": "v2" } ]
2017-02-01
[ [ "Braß", "Simon", "" ], [ "Hiller", "Gudrun", "" ], [ "Nisandzic", "Ivan", "" ] ]
We analyse $B\to K^\ast \ell\ell$ decays in the region of low hadronic recoil, where an operator product expansion (OPE) in $1/m_b$ applies. Using a local model for charm contributions based on $e^+ e^- \to hadrons$ against the OPE provides a data-driven method to access the limitations to the OPE's accuracy related to binnings in the dilepton mass. Model-independent fits to $B\to K^\ast \mu \mu $ low recoil angular observables exhibit presently only small sensitivity to different charm models. They give similar results as the fits based on the OPE, and are in agreement with the standard model, but leave also room for new physics. Measurements with resolution small enough to probe charm resonances would be desirable.
1801.09325
Teruyuki Kitabayashi
Teruyuki Kitabayashi, Hirona Matsumura, Kantaro Minakuchi and Hiroshi Ozaki
$S_4$ symmetric four-generation models for charged leptons
11 pages, no figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose $S_4$ symmetric four-generation models for charged leptons. Although an $S_4$ symmetric four-generation model has been already proposed, there are some additional symmetries in the model. We construct four-generation models for charged leptons with only requirement of exact $S_4$ symmetry. It turned out that at least one of the models is consistent with observations of charged lepton masses and predicts the mass of the charged lepton of the fourth generation to be 556 GeV.
[ { "created": "Mon, 29 Jan 2018 00:19:35 GMT", "version": "v1" }, { "created": "Sat, 30 Jun 2018 02:52:50 GMT", "version": "v2" } ]
2018-07-03
[ [ "Kitabayashi", "Teruyuki", "" ], [ "Matsumura", "Hirona", "" ], [ "Minakuchi", "Kantaro", "" ], [ "Ozaki", "Hiroshi", "" ] ]
We propose $S_4$ symmetric four-generation models for charged leptons. Although an $S_4$ symmetric four-generation model has been already proposed, there are some additional symmetries in the model. We construct four-generation models for charged leptons with only requirement of exact $S_4$ symmetry. It turned out that at least one of the models is consistent with observations of charged lepton masses and predicts the mass of the charged lepton of the fourth generation to be 556 GeV.
1808.07867
Christopher Lee
Guido Bell, Andrew Hornig, Christopher Lee, Jim Talbert
$e^+ e^-$ angularity distributions at NNLL$^\prime$ accuracy
51 pages + appendices, 18 figures. v2: minor clarifications and corrections, references updated. v3: version published in JHEP
JHEP 01 (2019) 147
10.1007/JHEP01(2019)147
SI-HEP-2018-19, LA-UR-18-24071, DESY 18-083
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present predictions for the $e^{+}e^{-}$ event shape angularities at NNLL$^{\prime}$ resummed and $\mathcal{O}(\alpha_s^{2})$ matched accuracy and compare them to LEP data at center-of-mass energies $Q=91.2$ GeV and $Q=197$ GeV. We perform the resummation within the framework of Soft-Collinear Effective Theory, and make use of recent results for the two-loop angularity soft function. We determine the remaining NNLL$^{\prime}$ and $\mathcal{O}(\alpha_s^2)$ ingredients from a fit to the EVENT2 generator, and implement a shape function with a renormalon-free gap parameter to model non-perturbative effects. Using values of the strong coupling $\alpha_s(m_Z)$ and the universal non-perturbative shift parameter $\Omega_1$ that are consistent with those obtained in previous fits to the thrust and $C$-parameter distributions, we find excellent agreement between our predictions and the LEP data for all angularities with $a\in[-1,0.5]$. This provides a robust test of the predictions of QCD, factorization, and the universal scaling of the non-perturbative shift across different angularities. Promisingly, our results indicate that current degeneracies in the $\{\alpha_s(m_Z),\Omega_1\}$ parameter space could be be alleviated upon fitting these parameters to experimental data for the angularity distributions.
[ { "created": "Thu, 23 Aug 2018 17:58:26 GMT", "version": "v1" }, { "created": "Mon, 24 Sep 2018 22:45:20 GMT", "version": "v2" }, { "created": "Mon, 28 Jan 2019 19:24:08 GMT", "version": "v3" } ]
2019-01-30
[ [ "Bell", "Guido", "" ], [ "Hornig", "Andrew", "" ], [ "Lee", "Christopher", "" ], [ "Talbert", "Jim", "" ] ]
We present predictions for the $e^{+}e^{-}$ event shape angularities at NNLL$^{\prime}$ resummed and $\mathcal{O}(\alpha_s^{2})$ matched accuracy and compare them to LEP data at center-of-mass energies $Q=91.2$ GeV and $Q=197$ GeV. We perform the resummation within the framework of Soft-Collinear Effective Theory, and make use of recent results for the two-loop angularity soft function. We determine the remaining NNLL$^{\prime}$ and $\mathcal{O}(\alpha_s^2)$ ingredients from a fit to the EVENT2 generator, and implement a shape function with a renormalon-free gap parameter to model non-perturbative effects. Using values of the strong coupling $\alpha_s(m_Z)$ and the universal non-perturbative shift parameter $\Omega_1$ that are consistent with those obtained in previous fits to the thrust and $C$-parameter distributions, we find excellent agreement between our predictions and the LEP data for all angularities with $a\in[-1,0.5]$. This provides a robust test of the predictions of QCD, factorization, and the universal scaling of the non-perturbative shift across different angularities. Promisingly, our results indicate that current degeneracies in the $\{\alpha_s(m_Z),\Omega_1\}$ parameter space could be be alleviated upon fitting these parameters to experimental data for the angularity distributions.
2202.04618
Angel Salvador Miramontes L\'opez
\'Angel S. Miramontes, Reinhard Alkofer, Christian S. Fischer and H\`elios Sanchis-Alepuz
Electromagnetic and strong isospin breaking in light meson masses
9 pages, 2 figures
null
10.1016/j.physletb.2022.137291
null
hep-ph hep-lat nucl-th
http://creativecommons.org/licenses/by/4.0/
We study electromagnetic as well as strong isospin breaking effects in the isospin mass splittings of light pseudoscalar and vector mesons. To this end we employ a coupled system of quark Dyson-Schwinger and meson Bethe-Salpeter equations whose interaction kernels contain gluon, pion and photon exchange interactions. In bound states, QCD-induced isospin breaking is manifest on different levels. On the one hand, a different explicit up- and down-quark mass directly affects the propagators of the constituent quarks. On the other hand, it leads to different interaction kernels within the isospin multiplets. In addition, electromagnetic isospin breaking is induced via a photon exchange diagram. Using the kaon iso-doublet and the charged pion masses as input to determine the up, down and strange quark masses we find for the pion, kaon and rho meson mass splittings different patterns each. In particular, our results provide evidence that the effects from two sources of mass splittings, the different quark masses and the different quark charges, do not add up linearly.
[ { "created": "Wed, 9 Feb 2022 18:27:39 GMT", "version": "v1" } ]
2022-07-20
[ [ "Miramontes", "Ángel S.", "" ], [ "Alkofer", "Reinhard", "" ], [ "Fischer", "Christian S.", "" ], [ "Sanchis-Alepuz", "Hèlios", "" ] ]
We study electromagnetic as well as strong isospin breaking effects in the isospin mass splittings of light pseudoscalar and vector mesons. To this end we employ a coupled system of quark Dyson-Schwinger and meson Bethe-Salpeter equations whose interaction kernels contain gluon, pion and photon exchange interactions. In bound states, QCD-induced isospin breaking is manifest on different levels. On the one hand, a different explicit up- and down-quark mass directly affects the propagators of the constituent quarks. On the other hand, it leads to different interaction kernels within the isospin multiplets. In addition, electromagnetic isospin breaking is induced via a photon exchange diagram. Using the kaon iso-doublet and the charged pion masses as input to determine the up, down and strange quark masses we find for the pion, kaon and rho meson mass splittings different patterns each. In particular, our results provide evidence that the effects from two sources of mass splittings, the different quark masses and the different quark charges, do not add up linearly.
hep-ph/0702153
Anna-Zuzana Dubnickova
S.Dubnicka, A.Z. Dubnickova, E.A. Kuraev
Ground state $1/2^+$ octet baryon sum rules predicting a chain of inequalities for hadron photoproduction total cross-sections on corresponding baryons
Revtex, 9 pages, 1 figure
null
null
null
hep-ph
null
Sum rules are derived relating Dirac mean square radii and anomalous magnetic moments of various couples of the ground state $1/2^+$ octet baryons with the convergent integral of the difference of hadron photoproduction cross-sections on the corresponding baryons. Taking into account the present knowledge of static parameters of baryons a chain of inequalities for total hadronic photoproduction cross-sections on baryons is found from those sum rules.
[ { "created": "Thu, 15 Feb 2007 16:19:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dubnicka", "S.", "" ], [ "Dubnickova", "A. Z.", "" ], [ "Kuraev", "E. A.", "" ] ]
Sum rules are derived relating Dirac mean square radii and anomalous magnetic moments of various couples of the ground state $1/2^+$ octet baryons with the convergent integral of the difference of hadron photoproduction cross-sections on the corresponding baryons. Taking into account the present knowledge of static parameters of baryons a chain of inequalities for total hadronic photoproduction cross-sections on baryons is found from those sum rules.