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1408.5005
Shu Luo
Shu Luo and Zhi-zhong Xing
Resolving the octant of theta_{23} via radiative mu-tau symmetry breaking
12 pages, 3 tables, 2 figures, minor changes, references updated, accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.90.073005
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We point out that the observed neutrino mixing pattern at low energies is very likely to originate from the 3 times 3 lepton flavor mixing matrix U which possesses the exact mu-tau permutation symmetry |U_{mu i}| = |U_{tau i}| (for i=1,2,3) at a superhigh energy scale Lambda_{mu tau} \sim 10^{14} GeV. The deviation of theta_{23} from 45^\circ and that of delta from 270^\circ in the standard parametrization of U are therefore a natural consequence of small mu-tau symmetry breaking via the renormalization-group equations (RGEs) running from Lambda_{mu tau} down to the electroweak scale Lambda_{EW} \sim 10^2 GeV. In fitting current experimental data we find that the RGE-corrected value of theta_{23} is uniquely correlated with the neutrino mass ordering: theta_{23} \simeq 42.4^\circ reported by Capozzi et al (or theta_{23} \simeq 48.9^\circ reported by Forero et al) at Lambda_{EW} can arise from theta_{23} = 45^\circ at Lambda_{mu tau} in the minimal supersymmetric standard model if the neutrino mass ordering is inverted (or normal). Accordingly, the preliminary best-fit results of delta at Lambda_{EW} can also evolve from delta = 270^\circ at Lambda_{mu tau} no matter whether the massive neutrinos are Dirac or Majorana particles.
[ { "created": "Thu, 21 Aug 2014 13:53:32 GMT", "version": "v1" }, { "created": "Wed, 1 Oct 2014 19:21:23 GMT", "version": "v2" } ]
2015-06-22
[ [ "Luo", "Shu", "" ], [ "Xing", "Zhi-zhong", "" ] ]
We point out that the observed neutrino mixing pattern at low energies is very likely to originate from the 3 times 3 lepton flavor mixing matrix U which possesses the exact mu-tau permutation symmetry |U_{mu i}| = |U_{tau i}| (for i=1,2,3) at a superhigh energy scale Lambda_{mu tau} \sim 10^{14} GeV. The deviation of theta_{23} from 45^\circ and that of delta from 270^\circ in the standard parametrization of U are therefore a natural consequence of small mu-tau symmetry breaking via the renormalization-group equations (RGEs) running from Lambda_{mu tau} down to the electroweak scale Lambda_{EW} \sim 10^2 GeV. In fitting current experimental data we find that the RGE-corrected value of theta_{23} is uniquely correlated with the neutrino mass ordering: theta_{23} \simeq 42.4^\circ reported by Capozzi et al (or theta_{23} \simeq 48.9^\circ reported by Forero et al) at Lambda_{EW} can arise from theta_{23} = 45^\circ at Lambda_{mu tau} in the minimal supersymmetric standard model if the neutrino mass ordering is inverted (or normal). Accordingly, the preliminary best-fit results of delta at Lambda_{EW} can also evolve from delta = 270^\circ at Lambda_{mu tau} no matter whether the massive neutrinos are Dirac or Majorana particles.
1510.00714
Andrew Williams
Andrew J. Williams
Explaining the Fermi Galactic Centre Excess in the CMSSM
16 pages, 3 figures
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an analysis of the compatibility between the Galactic Centre Excess (GCE) and the Constrained MSSM (CMSSM). We perform a global fit to the relevant experimental data including the GCE taking into account the systematic uncertainties. We find that the CMSSM is able to account for the GCE and maintain agreement with the other experimental searches, providing the first example that the GCE can be explained in the framework of universal supersymmetry. We map out the region compatible at 2 sigma and comment on its phenomenology. We find that for the CMSSM to explain the GCE the solution must lie close to the existing limits from LUX, IceCube and the LHC. We show that this provides definite predictions for Run 2 of the LHC, Xenon-1T and future observation with IceCube. Thus there exists the exciting possibility that the CMSSM could be observed in four distinct experimental channels over the next few years, which would be a striking signature for universal supersymmetry.
[ { "created": "Fri, 2 Oct 2015 20:04:36 GMT", "version": "v1" } ]
2015-10-06
[ [ "Williams", "Andrew J.", "" ] ]
We present an analysis of the compatibility between the Galactic Centre Excess (GCE) and the Constrained MSSM (CMSSM). We perform a global fit to the relevant experimental data including the GCE taking into account the systematic uncertainties. We find that the CMSSM is able to account for the GCE and maintain agreement with the other experimental searches, providing the first example that the GCE can be explained in the framework of universal supersymmetry. We map out the region compatible at 2 sigma and comment on its phenomenology. We find that for the CMSSM to explain the GCE the solution must lie close to the existing limits from LUX, IceCube and the LHC. We show that this provides definite predictions for Run 2 of the LHC, Xenon-1T and future observation with IceCube. Thus there exists the exciting possibility that the CMSSM could be observed in four distinct experimental channels over the next few years, which would be a striking signature for universal supersymmetry.
hep-ph/0106119
Shinta Kasuya
S. Kasuya and M. Kawasaki
Q-ball formation: Obstacle to Affleck-Dine baryogenesis in the gauge-mediated SUSY breaking ?
27 pages, RevTeX, 21 postscript figures included. The version to be published
Phys.Rev. D64 (2001) 123515
10.1103/PhysRevD.64.123515
null
hep-ph
null
We consider the Affleck-Dine baryogenesis comprehensively in the minimal supersymmetric standard model with gauge-mediated supersymmetry breaking. Considering the high temperature effects, we see that the Affleck-Dine field is naturally deformed into the form of the Q ball. In the natural scenario where the initial amplitude of the field and the A-terms are both determined by the nonrenormalizable superpotential, we obtain only very a narrow allowed region in the parameter space in order to explain the baryon number of the universe for the case that the Q-ball formation occurs just after baryon number production. Moreover, most of the parameter sets suited have already been excluded by current experiments. We also find new situations in which the Q-ball formation takes place rather late compared with baryon number creation. This situation is more preferable, since it allows a wider parameter region for naturally consistent scenarios, although it is still difficult to realize in the actual cosmological scenario.
[ { "created": "Tue, 12 Jun 2001 11:16:46 GMT", "version": "v1" }, { "created": "Thu, 11 Oct 2001 06:47:05 GMT", "version": "v2" } ]
2009-11-07
[ [ "Kasuya", "S.", "" ], [ "Kawasaki", "M.", "" ] ]
We consider the Affleck-Dine baryogenesis comprehensively in the minimal supersymmetric standard model with gauge-mediated supersymmetry breaking. Considering the high temperature effects, we see that the Affleck-Dine field is naturally deformed into the form of the Q ball. In the natural scenario where the initial amplitude of the field and the A-terms are both determined by the nonrenormalizable superpotential, we obtain only very a narrow allowed region in the parameter space in order to explain the baryon number of the universe for the case that the Q-ball formation occurs just after baryon number production. Moreover, most of the parameter sets suited have already been excluded by current experiments. We also find new situations in which the Q-ball formation takes place rather late compared with baryon number creation. This situation is more preferable, since it allows a wider parameter region for naturally consistent scenarios, although it is still difficult to realize in the actual cosmological scenario.
1702.02944
Doojin Kim
Doojin Kim, Jong-Chul Park, Seodong Shin
Dark Matter "Transporting" Mechanism Explaining Positron Excesses
14 pages, 3 figures
null
10.1007/JHEP04(2018)093
CERN-TH-2017-036
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel mechanism to explain the positron excesses, which are observed by satellite-based telescopes including PAMELA and AMS-02, in dark matter (DM) scenarios. The novelty behind the proposal is that it makes direct use of DM around the Galactic Center where DM populates most densely, allowing us to avoid tensions from cosmological and astrophysical measurements. The key ingredients of this mechanism include DM annihilation into unstable states with a very long laboratory-frame life time and their "retarded" decay near the Earth to electron-positron pair(s) possibly with other (in)visible particles. We argue that this sort of explanation is not in conflict with relevant constraints from big bang nucleosynthesis and cosmic microwave background. Regarding the resultant positron spectrum, we provide a generalized source term in the associated diffusion equation, which can be readily applicable to any type of two-"stage" DM scenarios wherein production of Standard Model particles occurs at completely different places from those of DM annihilation. We then conduct a data analysis with the recent AMS-02 data to validate our proposal.
[ { "created": "Thu, 9 Feb 2017 19:00:00 GMT", "version": "v1" }, { "created": "Fri, 20 Apr 2018 19:08:44 GMT", "version": "v2" } ]
2018-05-09
[ [ "Kim", "Doojin", "" ], [ "Park", "Jong-Chul", "" ], [ "Shin", "Seodong", "" ] ]
We propose a novel mechanism to explain the positron excesses, which are observed by satellite-based telescopes including PAMELA and AMS-02, in dark matter (DM) scenarios. The novelty behind the proposal is that it makes direct use of DM around the Galactic Center where DM populates most densely, allowing us to avoid tensions from cosmological and astrophysical measurements. The key ingredients of this mechanism include DM annihilation into unstable states with a very long laboratory-frame life time and their "retarded" decay near the Earth to electron-positron pair(s) possibly with other (in)visible particles. We argue that this sort of explanation is not in conflict with relevant constraints from big bang nucleosynthesis and cosmic microwave background. Regarding the resultant positron spectrum, we provide a generalized source term in the associated diffusion equation, which can be readily applicable to any type of two-"stage" DM scenarios wherein production of Standard Model particles occurs at completely different places from those of DM annihilation. We then conduct a data analysis with the recent AMS-02 data to validate our proposal.
hep-ph/0004232
Ed Stoeffhaas
M. M. Block, F. Halzen, T. Stanev
Extending the Frontiers - Reconciling Accelerator and Cosmic Ray p-p Cross Sections
6 pages, Latex, uses epsfig.sty, 5 postscript figures
Phys.Rev.D62:077501,2000
10.1103/PhysRevD.62.077501
NUHEP 706, MADPH-00-1172
hep-ph
null
We simultaneously fit a QCD-inspired parameterization of all accelerator data on forward proton-proton and antiproton-proton scattering amplitudes, together with cosmic ray data (using Glauber theory), to predict proton-air and proton-proton cross sections at energies near \sqrt s \approx 30 TeV. The p-air cosmic ray measurements provide a strong constraint on the inclusive particle production cross section, as well as greatly reducing the errors on the fit parameters---in turn, greatly reducing the errors in the high energy proton-proton and proton-air cross section predictions.
[ { "created": "Tue, 25 Apr 2000 20:53:55 GMT", "version": "v1" } ]
2011-05-12
[ [ "Block", "M. M.", "" ], [ "Halzen", "F.", "" ], [ "Stanev", "T.", "" ] ]
We simultaneously fit a QCD-inspired parameterization of all accelerator data on forward proton-proton and antiproton-proton scattering amplitudes, together with cosmic ray data (using Glauber theory), to predict proton-air and proton-proton cross sections at energies near \sqrt s \approx 30 TeV. The p-air cosmic ray measurements provide a strong constraint on the inclusive particle production cross section, as well as greatly reducing the errors on the fit parameters---in turn, greatly reducing the errors in the high energy proton-proton and proton-air cross section predictions.
hep-ph/9505229
Department of Theoretical Physics
A.A.Gvozdev, A.V.Kuznetsov, N.V.Mikheev and L.A.Vassilevskaya
THREE TYPES OF FERMION MIXING AND POSSIBLE MANIFESTATIONS OF A PATI--SALAM LEPTOQUARK IN THE LOW--ENERGY PROCESSES
9 pages, LaTeX, Talk given by A.V.Kuznetsov at the XXXth Rencontres de Moriond, Electroweak Interactions and Unified Theories, Les Arcs, Savoie, France, March 11-18, 1995
null
null
YARU-HE-95/02 (Yaroslavl State University)
hep-ph
null
I report the recent studies\cite{1,2} on the low--energy manifestations of a minimal extension of the Standard Model based on the quark-lepton symmetry $SU(4)_V \otimes SU(2)_L \otimes G_R$ of the Pati-Salam type. Given this symmetry the third type of mixing in the interactions ot the $SU(4)_V$ leptoquarks with quarks and leptons is shown to be required. An additional arbitrariness of the mixing parameters could allow, in principle, to decrease noticeably the lower bound on the vector leptoquark mass originated from the low-energy rare processes. The decays $\mu \rightarrow e \gamma$, $\mu \rightarrow e \gamma \gamma$, and $\mu \rightarrow e e \bar e$ via the vector leptoquark are analysed and the specific hierarchy of the decay probabilities $\Gamma(\mu \rightarrow e e \bar e) \gg \Gamma(\mu \rightarrow e \gamma \gamma) \gg \Gamma(\mu \rightarrow e \gamma)$ is shown to exist. The upper limits on the branching ratios at a level of $10^{-18}$ for the $\mu \rightarrow e \gamma \gamma$ decay and at a level of $10^{-15}$ for the $\mu \rightarrow e e \bar e$ decay are established.
[ { "created": "Thu, 4 May 1995 08:41:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gvozdev", "A. A.", "" ], [ "Kuznetsov", "A. V.", "" ], [ "Mikheev", "N. V.", "" ], [ "Vassilevskaya", "L. A.", "" ] ]
I report the recent studies\cite{1,2} on the low--energy manifestations of a minimal extension of the Standard Model based on the quark-lepton symmetry $SU(4)_V \otimes SU(2)_L \otimes G_R$ of the Pati-Salam type. Given this symmetry the third type of mixing in the interactions ot the $SU(4)_V$ leptoquarks with quarks and leptons is shown to be required. An additional arbitrariness of the mixing parameters could allow, in principle, to decrease noticeably the lower bound on the vector leptoquark mass originated from the low-energy rare processes. The decays $\mu \rightarrow e \gamma$, $\mu \rightarrow e \gamma \gamma$, and $\mu \rightarrow e e \bar e$ via the vector leptoquark are analysed and the specific hierarchy of the decay probabilities $\Gamma(\mu \rightarrow e e \bar e) \gg \Gamma(\mu \rightarrow e \gamma \gamma) \gg \Gamma(\mu \rightarrow e \gamma)$ is shown to exist. The upper limits on the branching ratios at a level of $10^{-18}$ for the $\mu \rightarrow e \gamma \gamma$ decay and at a level of $10^{-15}$ for the $\mu \rightarrow e e \bar e$ decay are established.
hep-ph/9804257
null
Samim Erhan and Peter E. Schlein
Evidence for xi- and t-dependent damping of the Pomeron Flux in the proton
19 pages, 7 Encapsulated Postscript figures, LaTex, Phys. Lett. B (in press - 1998)
Phys.Lett. B427 (1998) 389-397
10.1016/S0370-2693(98)00405-5
null
hep-ph
null
We show that a triple-Regge parametrization of inclusive single diffraction agrees with the data in the following two domains: (a) xi > 0.03 at all t, (b) |t| > 1 GeV^2 at all xi. Since the triple-Regge parametrization fails when applied to the full xi-t range of the total single-diffractive cross section, we conclude that damping occurs only at low-xi and low-|t|. We give a (``toy'') parametrization of the damping factor, D(xi), valid at low-|t|, which describes the diffractive differential cross-section (dsig/dt) data at the ISR and roughly accounts for the observed s-dependence of diffractive total cross-section up to Tevatron energies. However, an effective damping factor calculated for the CDF fitted function for dsig/dxidt at sqrt(s} = 1800 GeV and |t| = 0.05 GeV^2, suggests that, at fixed-xi, damping increases as s increases. We conjecture that, in the regions where the triple-Regge formalism describes the data and there is no evidence of damping, factorization is valid and the Pomeron-flux-factor may be universal. With the assumption that the observed damping is due to multi-Pomeron exchange, our results imply that the recent UA8 demonstration that the effective Pomeron trajectory flattens for |t| > 1 GeV$^2 is evidence for the onset of the perturbative 2-gluon pomeron. Our damping results may also shed some light on the self-consistency of recent measurements of hard-diffractive jet production cross sections in the UA8, CDF and ZEUS experiments.
[ { "created": "Wed, 8 Apr 1998 13:02:26 GMT", "version": "v1" } ]
2009-10-31
[ [ "Erhan", "Samim", "" ], [ "Schlein", "Peter E.", "" ] ]
We show that a triple-Regge parametrization of inclusive single diffraction agrees with the data in the following two domains: (a) xi > 0.03 at all t, (b) |t| > 1 GeV^2 at all xi. Since the triple-Regge parametrization fails when applied to the full xi-t range of the total single-diffractive cross section, we conclude that damping occurs only at low-xi and low-|t|. We give a (``toy'') parametrization of the damping factor, D(xi), valid at low-|t|, which describes the diffractive differential cross-section (dsig/dt) data at the ISR and roughly accounts for the observed s-dependence of diffractive total cross-section up to Tevatron energies. However, an effective damping factor calculated for the CDF fitted function for dsig/dxidt at sqrt(s} = 1800 GeV and |t| = 0.05 GeV^2, suggests that, at fixed-xi, damping increases as s increases. We conjecture that, in the regions where the triple-Regge formalism describes the data and there is no evidence of damping, factorization is valid and the Pomeron-flux-factor may be universal. With the assumption that the observed damping is due to multi-Pomeron exchange, our results imply that the recent UA8 demonstration that the effective Pomeron trajectory flattens for |t| > 1 GeV$^2 is evidence for the onset of the perturbative 2-gluon pomeron. Our damping results may also shed some light on the self-consistency of recent measurements of hard-diffractive jet production cross sections in the UA8, CDF and ZEUS experiments.
hep-ph/0011176
Raj Gandhi
Raj Gandhi
Ultra-High Energy Neutrinos: A Review of Theoretical and Phenomenological Issues
Invited Talk at Neutrino 2000, XIX International Conference on Neutrino Physics and Astrophysics, Sudbury, Canada, June 16-21, 2000. 12 pages. References updated; minor changes to text
Nucl.Phys.Proc.Suppl. 91 (2000) 453-461
10.1016/S0920-5632(00)00975-0
null
hep-ph astro-ph hep-ex
null
We review the phenomenology of ultra-high energy (UHE) neutrino detection. The motivations for looking for such neutrinos stemming from observational evidence and the potential for new physics discoveries are enumerated, and their expected sources and fluxes are given. Cross-sections with nucleons all the way upto neutrino energies of 10^20 eV, and the attenuation of the fluxes in the earth are discussed. Finally, sample event-rates for existing and future Water/Ice Cerenkov detectors are provided.
[ { "created": "Tue, 14 Nov 2000 10:27:22 GMT", "version": "v1" }, { "created": "Wed, 6 Dec 2000 05:07:53 GMT", "version": "v2" }, { "created": "Sat, 3 Feb 2001 06:01:18 GMT", "version": "v3" } ]
2009-10-31
[ [ "Gandhi", "Raj", "" ] ]
We review the phenomenology of ultra-high energy (UHE) neutrino detection. The motivations for looking for such neutrinos stemming from observational evidence and the potential for new physics discoveries are enumerated, and their expected sources and fluxes are given. Cross-sections with nucleons all the way upto neutrino energies of 10^20 eV, and the attenuation of the fluxes in the earth are discussed. Finally, sample event-rates for existing and future Water/Ice Cerenkov detectors are provided.
2005.13136
Carline Biesdorf
Luiz L. Lopes, Carline Biesdorf, D\'ebora P. Menezes
Modified MIT bag Models -- part I: Thermodynamic consistency, stability windows and symmetry group
14 pages, 10 figures
Phys. Scr. 96 065303 (2021)
10.1088/1402-4896/abef34
null
hep-ph astro-ph.HE nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study different variations of the MIT bag model. We start with the so called non-ideal bag model and discuss it in detail. Then we implement a vector interaction in the MIT bag model that simulates a meson exchange interaction and fix the quark-meson coupling constants via symmetry group theory. At the end we propose an original model, inspired by the Boguta-Bodmer models, which allows us to control the repulsion interaction at high densities. For each version of the model we obtain a stability window as predicted by the Bodmer-Witten conjecture and discuss its thermodynamic consistency.
[ { "created": "Wed, 27 May 2020 02:48:34 GMT", "version": "v1" }, { "created": "Thu, 28 May 2020 18:15:14 GMT", "version": "v2" }, { "created": "Mon, 29 Mar 2021 15:00:18 GMT", "version": "v3" } ]
2021-03-30
[ [ "Lopes", "Luiz L.", "" ], [ "Biesdorf", "Carline", "" ], [ "Menezes", "Débora P.", "" ] ]
In this work we study different variations of the MIT bag model. We start with the so called non-ideal bag model and discuss it in detail. Then we implement a vector interaction in the MIT bag model that simulates a meson exchange interaction and fix the quark-meson coupling constants via symmetry group theory. At the end we propose an original model, inspired by the Boguta-Bodmer models, which allows us to control the repulsion interaction at high densities. For each version of the model we obtain a stability window as predicted by the Bodmer-Witten conjecture and discuss its thermodynamic consistency.
1008.3155
Cen Zhang
Cen Zhang and Scott Willenbrock
Effective Field Theory for Top Quark Physics
7 pages, 5 figures. To appear in the Proceedings of the International Workshop on Top Quark Physics (top2010), Bruges, Belgium, May 31 - June 4, 2010
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Physics beyond the standard model can affect top-quark physics indirectly. We describe the effective field theory approach to describing such physics, and contrast it with the vertex-function approach that has been pursued previously. We argue that the effective field theory approach has many fundamental advantages and is also simpler.
[ { "created": "Wed, 18 Aug 2010 19:45:24 GMT", "version": "v1" } ]
2010-08-19
[ [ "Zhang", "Cen", "" ], [ "Willenbrock", "Scott", "" ] ]
Physics beyond the standard model can affect top-quark physics indirectly. We describe the effective field theory approach to describing such physics, and contrast it with the vertex-function approach that has been pursued previously. We argue that the effective field theory approach has many fundamental advantages and is also simpler.
2212.11674
Takaaki Nomura
Arindam Das, Takaaki Nomura, Takashi Shimomura
Multi muon/anti-muon signals via productions of gauge and scalar bosons in a $U(1)_{L_\mu-L_\tau}$ model at muonic colliders
16 pages, 6 figures, minor corrections are made
null
null
UME-PP-024, KYUSHU-HET-252
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We discuss the discovery potential of a promising signals, $3 \times \mu^+ \mu^-$ at a $\mu^+ \mu^-$ collider and $\mu^+ \mu^+ \mu^+ \mu^+ \mu^- \mu^- $ at a $\mu^+ \mu^+$ collider, that are obtained via production of $Z'$ and a new scalar boson $\phi$ in a spontaneously broken local $U(1)_{L_\mu - L_\tau}$ model. We consider the $Z'$ associated production from the process $\mu^+ \mu^- \to \phi Z'$ in addition to a muonphilic $Z'$ fusion process $\mu^+ \mu^\pm \to \phi \mu^+ \mu^\pm$. The scalar boson is associated with $U(1)_{L_\mu - L_\tau}$ symmetry breaking and dominantly decays into $Z' Z'$ mode. We carry out numerical simulation analysis for signal and background processes to estimate a discovery significance for different benchmark points. It is shown that our signal can be observed with integrated luminosity less than $\mathcal{O}(100)$ fb$^{-1}$ for both $\mu^+ \mu^-$ and $\mu^+ \mu^+$ colliders with more than 5-$\sigma$ significance.
[ { "created": "Thu, 22 Dec 2022 13:11:24 GMT", "version": "v1" }, { "created": "Wed, 4 Jan 2023 07:39:21 GMT", "version": "v2" } ]
2023-01-05
[ [ "Das", "Arindam", "" ], [ "Nomura", "Takaaki", "" ], [ "Shimomura", "Takashi", "" ] ]
We discuss the discovery potential of a promising signals, $3 \times \mu^+ \mu^-$ at a $\mu^+ \mu^-$ collider and $\mu^+ \mu^+ \mu^+ \mu^+ \mu^- \mu^- $ at a $\mu^+ \mu^+$ collider, that are obtained via production of $Z'$ and a new scalar boson $\phi$ in a spontaneously broken local $U(1)_{L_\mu - L_\tau}$ model. We consider the $Z'$ associated production from the process $\mu^+ \mu^- \to \phi Z'$ in addition to a muonphilic $Z'$ fusion process $\mu^+ \mu^\pm \to \phi \mu^+ \mu^\pm$. The scalar boson is associated with $U(1)_{L_\mu - L_\tau}$ symmetry breaking and dominantly decays into $Z' Z'$ mode. We carry out numerical simulation analysis for signal and background processes to estimate a discovery significance for different benchmark points. It is shown that our signal can be observed with integrated luminosity less than $\mathcal{O}(100)$ fb$^{-1}$ for both $\mu^+ \mu^-$ and $\mu^+ \mu^+$ colliders with more than 5-$\sigma$ significance.
hep-ph/0311049
Andrei Leonidov
Andrei Leonidov
Dense Gluon Matter in Nuclear Collisions
null
Phys.Usp.48:323-344,2005
10.1070/PU2005v048n04ABEH001890
FIAN/TD-16/03
hep-ph
null
Theoretical and phenomenological aspects of high energy heavy ion collisions are reviewed. Main emphasis is on ideas related to Color Glass Condensate (CGC) physics.
[ { "created": "Tue, 4 Nov 2003 15:07:37 GMT", "version": "v1" } ]
2010-11-30
[ [ "Leonidov", "Andrei", "" ] ]
Theoretical and phenomenological aspects of high energy heavy ion collisions are reviewed. Main emphasis is on ideas related to Color Glass Condensate (CGC) physics.
1409.3648
Motohiko Yoshimura
M. Yoshimura, N. Sasao, and M. Tanaka
Experimental method of detecting relic neutrino by atomic de-excitation
7 pages, 4 figures
Phys. Rev. D 91, 063516 (2015)
10.1103/PhysRevD.91.063516
OU-HET 826
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cosmic background neutrino of temperature 1.9 K affects rates of radiative emission of neutrino pair (RENP) from metastable excited atoms, since its presence blocks the pair emission by the Pauli exclusion principle. We quantitatively investigate how the Pauli blocking distorts the photon energy spectrum and calculate its sensitivity to cosmic parameters such as the neutrino temperature and its chemical potential. Important quantities for high sensitivities to these parameter measurement are found to be the level spacing of atomic de-excitation and the unknown mass value of lightest neutrino, in particular their mutual relation.
[ { "created": "Fri, 12 Sep 2014 04:52:58 GMT", "version": "v1" } ]
2015-03-18
[ [ "Yoshimura", "M.", "" ], [ "Sasao", "N.", "" ], [ "Tanaka", "M.", "" ] ]
The cosmic background neutrino of temperature 1.9 K affects rates of radiative emission of neutrino pair (RENP) from metastable excited atoms, since its presence blocks the pair emission by the Pauli exclusion principle. We quantitatively investigate how the Pauli blocking distorts the photon energy spectrum and calculate its sensitivity to cosmic parameters such as the neutrino temperature and its chemical potential. Important quantities for high sensitivities to these parameter measurement are found to be the level spacing of atomic de-excitation and the unknown mass value of lightest neutrino, in particular their mutual relation.
hep-ph/9611273
null
R. N. Mohapatra and A. Riotto
Supersymmetric models with anomalous U(1) mediated supersymmetry breaking
18 pages latex; 3 figures
Phys.Rev. D55 (1997) 4262-4267
10.1103/PhysRevD.55.4262
Fermilab-Pub-96/410; UMD-PP-97-54
hep-ph
null
We construct realistic supergravity models where supersymmetry breaking arises from the D-terms of an anomalous U(1) gauge symmetry broken at the Planck scale. Effective action for these theories at sub-Planck energies (including higher dimensional terms in the superpotential) are severely restricted by the U(1) symmetry and by the assumption that they arise from an underlying renormalizable theory at a higher scale. Phenomenological consequences of these models are studied. They are found to have the attractive feature that the gaugino masses, the A and B terms and the mass splittings between the like-charged squarks of the first two generations compared to their average masses can all be naturally suppressed. As a result, the electric dipole moment of the neutron as well as the flavor changing neutral current effects are predicted to be naturally small. These models also predict the value of the $\mu$-term to be naturally small and have the potential to qualitatively explain the observed mass hierarchy among quarks and leptons. We then discuss examples of high scale renormalizable theories that can justify the choice of the the effective action from naturalness point of view.
[ { "created": "Thu, 7 Nov 1996 20:50:13 GMT", "version": "v1" } ]
2016-09-06
[ [ "Mohapatra", "R. N.", "" ], [ "Riotto", "A.", "" ] ]
We construct realistic supergravity models where supersymmetry breaking arises from the D-terms of an anomalous U(1) gauge symmetry broken at the Planck scale. Effective action for these theories at sub-Planck energies (including higher dimensional terms in the superpotential) are severely restricted by the U(1) symmetry and by the assumption that they arise from an underlying renormalizable theory at a higher scale. Phenomenological consequences of these models are studied. They are found to have the attractive feature that the gaugino masses, the A and B terms and the mass splittings between the like-charged squarks of the first two generations compared to their average masses can all be naturally suppressed. As a result, the electric dipole moment of the neutron as well as the flavor changing neutral current effects are predicted to be naturally small. These models also predict the value of the $\mu$-term to be naturally small and have the potential to qualitatively explain the observed mass hierarchy among quarks and leptons. We then discuss examples of high scale renormalizable theories that can justify the choice of the the effective action from naturalness point of view.
hep-ph/9612358
Masayasu Harada
Masayasu Harada (Syracuse U.), Akihiro Shibata (KEK,Japan)
The Pion Decay Constants and the Rho-Meson Mass at Finite Temperature in the Hidden Local Symmetry
We added a comment on the correction to the rho-meson mass from the omega-pi loop. This is the final version to be published in Phys. Rev. D. 19 pages (LaTeX-RevTeX), 7 PostScript figures
Phys.Rev.D55:6716-6724,1997
10.1103/PhysRevD.55.6716
SU-4240-652 & KEK preprint 96-150
hep-ph nucl-th
null
We study the temperature dependence of the pion decay constant and rho-meson mass in the hidden local symmetry model at one loop. Using the standard imaginary time formalism, we include the thermal effect of rho meson as well as that of pion. We show that the pion gives a dominant contribution to the pion decay constant and rho-meson contribution slightly decreases the critical temperature. The rho-meson pole mass increases as T^4/m_\rho^2 at low temperature dominated by the pion-loop effect. At high temperature, although the pion-loop effect decreases the rho-meson mass, the rho-loop contribution overcomes the pion-loop contribution and rho-meson mass increases with temperature. We also show that the conventional parameter a is stable as the temperature increases.
[ { "created": "Fri, 13 Dec 1996 20:04:06 GMT", "version": "v1" }, { "created": "Tue, 18 Mar 1997 00:39:32 GMT", "version": "v2" } ]
2009-12-30
[ [ "Harada", "Masayasu", "", "Syracuse U." ], [ "Shibata", "Akihiro", "", "KEK,Japan" ] ]
We study the temperature dependence of the pion decay constant and rho-meson mass in the hidden local symmetry model at one loop. Using the standard imaginary time formalism, we include the thermal effect of rho meson as well as that of pion. We show that the pion gives a dominant contribution to the pion decay constant and rho-meson contribution slightly decreases the critical temperature. The rho-meson pole mass increases as T^4/m_\rho^2 at low temperature dominated by the pion-loop effect. At high temperature, although the pion-loop effect decreases the rho-meson mass, the rho-loop contribution overcomes the pion-loop contribution and rho-meson mass increases with temperature. We also show that the conventional parameter a is stable as the temperature increases.
2008.09383
Yannick Ulrich
Yannick Ulrich
McMule -- QED Corrections for Low-Energy Experiments
PhD thesis, 155 pages, many figures, partially based on arXiv:2007.01654, arXiv:1909.10244, and arXiv:1811.06461
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present McMule, a unified framework for the calculation of NLO and NNLO corrections to many processes in QED with massive fermions. This easily extendable program allows users to calculate an arbitrary observable for any of the processes implemented. These include various lepton decays as well as certain low-energy scattering experiments such as $e\mu\to e\mu$ and $\ell p\to\ell p$ that can be measured to high enough a precision to warrant QED corrections. As part of our discussion, we will present a pedagogical introduction to how these calculations are performed, focusing on technical aspects supplemented with examples. Our goal is to provide a useful introduction for those entering the field, covering all aspects relevant for the practitioner.
[ { "created": "Fri, 21 Aug 2020 09:23:02 GMT", "version": "v1" } ]
2020-08-24
[ [ "Ulrich", "Yannick", "" ] ]
We present McMule, a unified framework for the calculation of NLO and NNLO corrections to many processes in QED with massive fermions. This easily extendable program allows users to calculate an arbitrary observable for any of the processes implemented. These include various lepton decays as well as certain low-energy scattering experiments such as $e\mu\to e\mu$ and $\ell p\to\ell p$ that can be measured to high enough a precision to warrant QED corrections. As part of our discussion, we will present a pedagogical introduction to how these calculations are performed, focusing on technical aspects supplemented with examples. Our goal is to provide a useful introduction for those entering the field, covering all aspects relevant for the practitioner.
1602.03627
Shasanka Mohan Roy
S. M. Roy (HBCSE, Tata Institute of Fundamental Research, Mumbai)
Pomeron pole plus grey disk model: real parts, inelastic cross sections and LHC data
6 pages, 5 figures, 2 tables
null
10.1016/j.physletb.2016.11.025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I propose a two component analytic formula $F(s,t)=F^{(1)}(s,t)+F^{(2)}(s,t)$ for $(ab\rightarrow ab) +(a\bar{b}\rightarrow a\bar{b})$ scattering at energies $\ge 100 GeV$ ,where $s,t$ denote squares of c.m. energy and momentum transfer.It saturates the Froissart-Martin bound and obeys Auberson-Kinoshita-Martin (AKM) \cite{AKM1971} scaling. I choose $Im F^{(1)}(s,0)+Im F^{(2)}(s,0)$ as given by Particle Data Group (PDG) fits to total cross sections. The PDG formula is extended to non-zero momentum transfers using partial waves of $Im F^{(1)}$ and $Im F^{(2)}$ motivated by Pomeron pole and 'grey disk' amplitudes . $Re F(s,t)$ is deduced from real analyticity: I prove that $Re F(s,t)/ImF(s,0) \rightarrow (\pi/\ln{s}) d/d\tau (\tau Im F(s,t)/ImF(s,0) )$ for $s\rightarrow \infty$ with $\tau=t (ln s)^2$ fixed, and apply it to $F^{(2)}$.Using also the forward slope fit by Schegelsky-Ryskin , the model gives real parts,differential cross sections for $(-t)<.3 GeV^2$, and inelastic cross sections in good agreement with data at $546 GeV, 1.8 TeV,7 TeV$ and $ 8 TeV $. It predicts for inelastic cross sections for $pp$ or $\bar{p} p$, $\sigma_{inel}=72.7\pm 1.0 mb$ at $7TeV$ and $74.2 \pm 1.0mb$ at $8 TeV$ in agreement with $pp$ Totem experimental values $73.1\pm 1.3 mb $ and $74.7\pm 1.7 mb$ respectively, and with Atlas values $71.3\pm 0.9 mb$ and $71.7\pm 0.7mb$ respectively. The predictions at $546 GeV$ and $1800 GeV$ also agree with $\bar{p} p$ experimental results of Abe et al \cite{Abe} at $546 GeV$ and $1800 GeV$. The model yields for $\sqrt{s}> 0.5 TeV$, with PDG2013 total cross sections , and Schegelsky-Ryskin slopes as input, $\sigma_{inel} (s) =22.6 + .034 ln s + .158 (ln s)^2 mb , and \sigma_{inel} / \sigma_{tot} \rightarrow 0.56, s\rightarrow \infty ,$ where $s$ is in $GeV^2$
[ { "created": "Thu, 11 Feb 2016 07:02:21 GMT", "version": "v1" }, { "created": "Tue, 16 Feb 2016 07:21:49 GMT", "version": "v2" }, { "created": "Wed, 1 Jun 2016 12:54:12 GMT", "version": "v3" }, { "created": "Sat, 18 Jun 2016 16:55:53 GMT", "version": "v4" }, { "created": "Tue, 30 Aug 2016 10:33:57 GMT", "version": "v5" }, { "created": "Thu, 13 Oct 2016 12:57:18 GMT", "version": "v6" }, { "created": "Wed, 2 Nov 2016 14:51:34 GMT", "version": "v7" } ]
2017-01-04
[ [ "Roy", "S. M.", "", "HBCSE, Tata Institute of Fundamental Research, Mumbai" ] ]
I propose a two component analytic formula $F(s,t)=F^{(1)}(s,t)+F^{(2)}(s,t)$ for $(ab\rightarrow ab) +(a\bar{b}\rightarrow a\bar{b})$ scattering at energies $\ge 100 GeV$ ,where $s,t$ denote squares of c.m. energy and momentum transfer.It saturates the Froissart-Martin bound and obeys Auberson-Kinoshita-Martin (AKM) \cite{AKM1971} scaling. I choose $Im F^{(1)}(s,0)+Im F^{(2)}(s,0)$ as given by Particle Data Group (PDG) fits to total cross sections. The PDG formula is extended to non-zero momentum transfers using partial waves of $Im F^{(1)}$ and $Im F^{(2)}$ motivated by Pomeron pole and 'grey disk' amplitudes . $Re F(s,t)$ is deduced from real analyticity: I prove that $Re F(s,t)/ImF(s,0) \rightarrow (\pi/\ln{s}) d/d\tau (\tau Im F(s,t)/ImF(s,0) )$ for $s\rightarrow \infty$ with $\tau=t (ln s)^2$ fixed, and apply it to $F^{(2)}$.Using also the forward slope fit by Schegelsky-Ryskin , the model gives real parts,differential cross sections for $(-t)<.3 GeV^2$, and inelastic cross sections in good agreement with data at $546 GeV, 1.8 TeV,7 TeV$ and $ 8 TeV $. It predicts for inelastic cross sections for $pp$ or $\bar{p} p$, $\sigma_{inel}=72.7\pm 1.0 mb$ at $7TeV$ and $74.2 \pm 1.0mb$ at $8 TeV$ in agreement with $pp$ Totem experimental values $73.1\pm 1.3 mb $ and $74.7\pm 1.7 mb$ respectively, and with Atlas values $71.3\pm 0.9 mb$ and $71.7\pm 0.7mb$ respectively. The predictions at $546 GeV$ and $1800 GeV$ also agree with $\bar{p} p$ experimental results of Abe et al \cite{Abe} at $546 GeV$ and $1800 GeV$. The model yields for $\sqrt{s}> 0.5 TeV$, with PDG2013 total cross sections , and Schegelsky-Ryskin slopes as input, $\sigma_{inel} (s) =22.6 + .034 ln s + .158 (ln s)^2 mb , and \sigma_{inel} / \sigma_{tot} \rightarrow 0.56, s\rightarrow \infty ,$ where $s$ is in $GeV^2$
2312.13740
K{\aa}re Fridell
K\r{a}re Fridell, Chandan Hati, and Volodymyr Takhistov
Non-Canonical Nucleon Decays as Window into Light New Physics
8 pages, 2 figures, version accepted for publication
null
null
KEK-TH-2588, KEK-Cosmo-0336, KEK-QUP-2023-0038, IPMU23-0051, IFIC/23-54, ULB-TH/23-18
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Nucleon decays are generic predictions of motivated theories, including those based on the unification of forces and supersymmetry. We demonstrate that non-canonical nucleon decays offer a unique opportunity to broadly probe light new particles beyond the Standard Model with masses below $\sim$few GeV over decades in mass range, including axion-like particles, dark photons, sterile neutrinos, and scalar dark matter. Conventional searches can misinterpret and even completely miss such new physics. We propose a general strategy based on momenta of visible decay final states to probe these processes, offering a rich physics program for existing and upcoming experiments such as Super-Kamiokande, Hyper-Kamiokande, DUNE, and JUNO.
[ { "created": "Thu, 21 Dec 2023 11:18:51 GMT", "version": "v1" }, { "created": "Wed, 10 Jul 2024 02:38:03 GMT", "version": "v2" } ]
2024-07-11
[ [ "Fridell", "Kåre", "" ], [ "Hati", "Chandan", "" ], [ "Takhistov", "Volodymyr", "" ] ]
Nucleon decays are generic predictions of motivated theories, including those based on the unification of forces and supersymmetry. We demonstrate that non-canonical nucleon decays offer a unique opportunity to broadly probe light new particles beyond the Standard Model with masses below $\sim$few GeV over decades in mass range, including axion-like particles, dark photons, sterile neutrinos, and scalar dark matter. Conventional searches can misinterpret and even completely miss such new physics. We propose a general strategy based on momenta of visible decay final states to probe these processes, offering a rich physics program for existing and upcoming experiments such as Super-Kamiokande, Hyper-Kamiokande, DUNE, and JUNO.
hep-ph/0002042
Tao Han
V. Barger, T. Han and C.-G. Zhou
Higgs Boson Decays to tau-pairs in the s-channel at a Muon Collider
to appear in PLB
Phys.Lett.B480:140-148,2000
10.1016/S0370-2693(00)00372-5
MADPH-00-1154
hep-ph
null
We study the observability of the $\tautau$ decay mode of a Higgs boson produced in the $s$-channel at a muon collider. We find that the spin correlations of the $\tautau$ in $\tau\to \pi\nu_{\tau}, \rho\nu_{\tau}$ decays are discriminative between the Higgs boson signal and the Standard Model background. Observation of the predicted distinctive distribution can confirm the spin-0 nature of the Higgs resonance. The relative coupling strength of the Higgs boson to $b$ and $\tau$ can also be experimentally determined.
[ { "created": "Thu, 3 Feb 2000 17:51:17 GMT", "version": "v1" }, { "created": "Fri, 24 Mar 2000 17:40:48 GMT", "version": "v2" } ]
2009-09-15
[ [ "Barger", "V.", "" ], [ "Han", "T.", "" ], [ "Zhou", "C. -G.", "" ] ]
We study the observability of the $\tautau$ decay mode of a Higgs boson produced in the $s$-channel at a muon collider. We find that the spin correlations of the $\tautau$ in $\tau\to \pi\nu_{\tau}, \rho\nu_{\tau}$ decays are discriminative between the Higgs boson signal and the Standard Model background. Observation of the predicted distinctive distribution can confirm the spin-0 nature of the Higgs resonance. The relative coupling strength of the Higgs boson to $b$ and $\tau$ can also be experimentally determined.
2005.08920
Danny Marfatia
Alakabha Datta, Saeed Kamali, Danny Marfatia
Dark sector origin of the KOTO and MiniBooNE anomalies
10 pages, 1 figure, 2 tables. Version to appear in PLB
Phys. Lett. B 807 : 135579 (2020)
10.1016/j.physletb.2020.135579
UMISS-HEP-2010-02
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a dark sector model that reproduces the KOTO, MiniBooNE and muon anomalous magnetic moment anomalies. The dark sector is comprised of a light scalar singlet $S$ that has a large coupling to a slightly heavier sterile neutrino that mixes with the active neutrinos. The scalar couples to standard model fermions via Yukawa couplings, and to photons via a higher-dimensional coupling. The KOTO signal is a result of the flavor-changing penguin process $K_L \to \pi^0 S$ followed by the decay of $S$ to neutrinos. The sterile neutrino produced in neutrino-nucleus scattering at MiniBooNE decays to an active neutrino and $S$, which decays electromagnetically and creates an event excess at low energies.
[ { "created": "Mon, 18 May 2020 17:46:27 GMT", "version": "v1" }, { "created": "Mon, 22 Jun 2020 15:31:33 GMT", "version": "v2" } ]
2020-07-02
[ [ "Datta", "Alakabha", "" ], [ "Kamali", "Saeed", "" ], [ "Marfatia", "Danny", "" ] ]
We present a dark sector model that reproduces the KOTO, MiniBooNE and muon anomalous magnetic moment anomalies. The dark sector is comprised of a light scalar singlet $S$ that has a large coupling to a slightly heavier sterile neutrino that mixes with the active neutrinos. The scalar couples to standard model fermions via Yukawa couplings, and to photons via a higher-dimensional coupling. The KOTO signal is a result of the flavor-changing penguin process $K_L \to \pi^0 S$ followed by the decay of $S$ to neutrinos. The sterile neutrino produced in neutrino-nucleus scattering at MiniBooNE decays to an active neutrino and $S$, which decays electromagnetically and creates an event excess at low energies.
hep-ph/0601142
Piyabut Burikham
Piyabut Burikham
TeV-Scale Stringy Signatures at the Electron-positron Collider
22 pages,8 figures, expanded content, added references
Phys.Rev. D73 (2006) 055006
10.1103/PhysRevD.73.055006
null
hep-ph
null
We investigate the TeV-scale stringy signals of the four-fermion scattering at the electron-positron collider with the center of mass energy 500-1000 GeV. The nature of the stringy couplings leads to distinguishable asymmetries comparing to the other new physics models. Specifically, the stringy states in the four-fermion scattering at the leading-order corrections are of spin-1 and 2 with the chiral couplings inherited from the gauge bosons identified as the zeroth-mode string states. The angular left-right, forward-backward, center-edge asymmetries and the corresponding polarized-beam asymmetries are investigated. The low-energy stringy corrections are compared to the ones induced by the Kaluza-Klein (KK) gravitons. The angular left-right asymmetry of the scattering with the final states of u and d-type quarks, namely c and b, shows significant deviations from the Standard Model values. The center-edge and forward-backward asymmetries for all final-states fermions also show significant deviations from the corresponding Standard Model values. The differences between the signatures induced by the stringy corrections and the KK gravitons are appreciable in both angular left-right and forward-backward asymmetries.
[ { "created": "Tue, 17 Jan 2006 23:33:49 GMT", "version": "v1" }, { "created": "Tue, 28 Feb 2006 00:38:44 GMT", "version": "v2" } ]
2009-11-11
[ [ "Burikham", "Piyabut", "" ] ]
We investigate the TeV-scale stringy signals of the four-fermion scattering at the electron-positron collider with the center of mass energy 500-1000 GeV. The nature of the stringy couplings leads to distinguishable asymmetries comparing to the other new physics models. Specifically, the stringy states in the four-fermion scattering at the leading-order corrections are of spin-1 and 2 with the chiral couplings inherited from the gauge bosons identified as the zeroth-mode string states. The angular left-right, forward-backward, center-edge asymmetries and the corresponding polarized-beam asymmetries are investigated. The low-energy stringy corrections are compared to the ones induced by the Kaluza-Klein (KK) gravitons. The angular left-right asymmetry of the scattering with the final states of u and d-type quarks, namely c and b, shows significant deviations from the Standard Model values. The center-edge and forward-backward asymmetries for all final-states fermions also show significant deviations from the corresponding Standard Model values. The differences between the signatures induced by the stringy corrections and the KK gravitons are appreciable in both angular left-right and forward-backward asymmetries.
1002.4252
Daniel Mueller
Daniel M\"uller, Michael Buballa and Jochen Wambach
The Quark Propagator in the NJL Model in a self-consistent 1/Nc Expansion
14 pages, 19 figures
Phys.Rev.D81:094022,2010
10.1103/PhysRevD.81.094022
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quark propagator is calculated in the Nambu-Jona-Lasinio (NJL) model in a self-consistent 1/Nc-expansion at next-to-leading order. The calculations are carried out iteratively in Euclidean space. The chiral quark condensate and its dependence on temperature and chemical potential is calculated directly and compared with the mean-field results. In the chiral limit, we find a second-order phase transition at finite temperature and zero chemical potential, in agreement with universality arguments. At zero temperature and finite chemical potential, the phase transition is first order. In comparison with the mean-field results, the critical temperature and chemical potential are slightly reduced. We determine spectral functions from the Euclidean propagators by employing the Maximum-Entropy-Method (MEM). Thereby quark and meson masses are estimated and decay channels identified. For testing this method, we also apply it to evaluate perturbative spectral functions, which can be calculated directly in Minkowski space. In most cases we find that MEM is able to reproduce the rough features of the spectral functions, but not the details.
[ { "created": "Tue, 23 Feb 2010 14:16:23 GMT", "version": "v1" }, { "created": "Tue, 4 May 2010 11:37:57 GMT", "version": "v2" } ]
2010-05-24
[ [ "Müller", "Daniel", "" ], [ "Buballa", "Michael", "" ], [ "Wambach", "Jochen", "" ] ]
The quark propagator is calculated in the Nambu-Jona-Lasinio (NJL) model in a self-consistent 1/Nc-expansion at next-to-leading order. The calculations are carried out iteratively in Euclidean space. The chiral quark condensate and its dependence on temperature and chemical potential is calculated directly and compared with the mean-field results. In the chiral limit, we find a second-order phase transition at finite temperature and zero chemical potential, in agreement with universality arguments. At zero temperature and finite chemical potential, the phase transition is first order. In comparison with the mean-field results, the critical temperature and chemical potential are slightly reduced. We determine spectral functions from the Euclidean propagators by employing the Maximum-Entropy-Method (MEM). Thereby quark and meson masses are estimated and decay channels identified. For testing this method, we also apply it to evaluate perturbative spectral functions, which can be calculated directly in Minkowski space. In most cases we find that MEM is able to reproduce the rough features of the spectral functions, but not the details.
1203.4821
Adam Martin
Graham D. Kribs, Adam Martin
Supersoft Supersymmetry is Super-Safe
13 pages, 8 figures
null
10.1103/PhysRevD.85.115014
FERMILAB-PUB-12-074-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that supersymmetric models with a large Dirac gluino mass can evade much of the jets plus missing energy searches at LHC. Dirac gaugino masses arise from "supersoft" operators that lead to finite one-loop suppressed contributions to the scalar masses. A little hierarchy between the Dirac gluino mass 5 - 10 times heavier than the squark masses is automatic and technically natural, in stark contrast to supersymmetric models with Majorana gaugino masses. At the LHC, colored sparticle production is suppressed not only by the absence of gluino pair (or associated) production, but also because several of the largest squark pair production channels are suppressed or absent. We recast the null results from the present jets plus missing energy searches at LHC for supersymmetry onto a supersoft supersymmetric simplified model (SSSM). Assuming a massless LSP, we find the strongest bounds are: 748 GeV from a 2j + MET search at ATLAS (4.7 fb^{-1}), and 684 GeV from a combined jets plus missing energy search using $\alpha_T$ at CMS (1.1 fb^{-1}). In the absence of a future observation, we estimate the bounds on the squark masses to improve only modestly with increased luminosity. We also briefly consider the further weakening in the bounds as the LSP mass is increased.
[ { "created": "Wed, 21 Mar 2012 20:02:11 GMT", "version": "v1" } ]
2013-05-30
[ [ "Kribs", "Graham D.", "" ], [ "Martin", "Adam", "" ] ]
We show that supersymmetric models with a large Dirac gluino mass can evade much of the jets plus missing energy searches at LHC. Dirac gaugino masses arise from "supersoft" operators that lead to finite one-loop suppressed contributions to the scalar masses. A little hierarchy between the Dirac gluino mass 5 - 10 times heavier than the squark masses is automatic and technically natural, in stark contrast to supersymmetric models with Majorana gaugino masses. At the LHC, colored sparticle production is suppressed not only by the absence of gluino pair (or associated) production, but also because several of the largest squark pair production channels are suppressed or absent. We recast the null results from the present jets plus missing energy searches at LHC for supersymmetry onto a supersoft supersymmetric simplified model (SSSM). Assuming a massless LSP, we find the strongest bounds are: 748 GeV from a 2j + MET search at ATLAS (4.7 fb^{-1}), and 684 GeV from a combined jets plus missing energy search using $\alpha_T$ at CMS (1.1 fb^{-1}). In the absence of a future observation, we estimate the bounds on the squark masses to improve only modestly with increased luminosity. We also briefly consider the further weakening in the bounds as the LSP mass is increased.
hep-ph/0608340
Felipe J. Llanes-Estrada
Felipe J. Llanes-Estrada, Tim Van Cauteren and Angel Paramo Martin (Complutense)
Fermion family recurrences in the Dyson-Schwinger formalism
null
Eur.Phys.J.C51:945-952,2007
10.1140/epjc/s10052-007-0349-9
null
hep-ph
null
We study the multiple solutions of the truncated propagator Dyson-Schwinger equation for a simple fermion theory with Yukawa coupling to a scalar field. Upon increasing the coupling constant $g$, other parameters being fixed, more than one non-perturbative solution breaking chiral symmetry becomes possible and we find these numerically. These ``recurrences'' appear as a mechanism to generate different fermion generations as quanta of the same fundamental field in an interacting field theory, without assuming any composite structure. The number of recurrences or flavors is reduced to a question about the value of the Yukawa coupling, and has no special profound significance in the Standard Model. The resulting mass function can have one or more nodes and the measurement that potentially detects them can be thought of as a collider-based test of the virtual dispersion relation $E=\sqrt{p^2+M(p^2)^2}$ for the charged lepton member of each family. This requires three independent measurements of the charged lepton's energy, three-momentum and off-shellness. We illustrate how this can be achieved for the (more difficult) case of the tau lepton.
[ { "created": "Thu, 31 Aug 2006 13:31:17 GMT", "version": "v1" }, { "created": "Wed, 9 May 2007 10:51:50 GMT", "version": "v2" } ]
2008-11-26
[ [ "Llanes-Estrada", "Felipe J.", "", "Complutense" ], [ "Van Cauteren", "Tim", "", "Complutense" ], [ "Martin", "Angel Paramo", "", "Complutense" ] ]
We study the multiple solutions of the truncated propagator Dyson-Schwinger equation for a simple fermion theory with Yukawa coupling to a scalar field. Upon increasing the coupling constant $g$, other parameters being fixed, more than one non-perturbative solution breaking chiral symmetry becomes possible and we find these numerically. These ``recurrences'' appear as a mechanism to generate different fermion generations as quanta of the same fundamental field in an interacting field theory, without assuming any composite structure. The number of recurrences or flavors is reduced to a question about the value of the Yukawa coupling, and has no special profound significance in the Standard Model. The resulting mass function can have one or more nodes and the measurement that potentially detects them can be thought of as a collider-based test of the virtual dispersion relation $E=\sqrt{p^2+M(p^2)^2}$ for the charged lepton member of each family. This requires three independent measurements of the charged lepton's energy, three-momentum and off-shellness. We illustrate how this can be achieved for the (more difficult) case of the tau lepton.
1109.2444
Antonio Vairo
Antonio Vairo
Effective Field Theories for Quarkonium and Dipole Transitions
13 pages, 12 figures. Plenary talk at XIV International Conference on Hadron Spectroscopy (hadron2011), 13-17 June 2011, Munich, Germany
null
null
TUM-EFT 23/11
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effective field theories for quarkonium at zero and finite temperature provide an unifying description for a wide class of phenomena. As an example, we discuss physical effects induced by dipole transitions.
[ { "created": "Mon, 12 Sep 2011 12:38:23 GMT", "version": "v1" } ]
2011-09-13
[ [ "Vairo", "Antonio", "" ] ]
Effective field theories for quarkonium at zero and finite temperature provide an unifying description for a wide class of phenomena. As an example, we discuss physical effects induced by dipole transitions.
0903.0396
Michael Mitrovski
Hannah Petersen, Michael Mitrovski, Tim Schuster, and Marcus Bleicher
Centrality and system size dependence of (multi-strange) hyperons at 40$A$ and 158$A$ GeV: A comparison between a binary collision and a Boltzmann + hydrodynamic hybrid model
8 pages, 8 figures
Phys.Rev.C80,054910,2009
10.1103/PhysRevC.80.054910
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results on the centrality and system size dependence of (multi-strange)hyperons in Pb+Pb collisions at 40$A$ and 158$A$ GeV from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD-v2.3) model and a coupled Boltzmann+hydrodynamics calculation. The second approach is realized in a hybrid fashion based on UrQMD with an intermediate hydrodynamical evolution for the hot and dense stage of the collision. This implementation allows a comparison of microscopic transport calculations with hydrodynamic simulations to explore the transition from a system that is not fully equilibrated such as C+C or Si+Si collisions, to a supposedly fully equilibrated system, such as that created in Pb+Pb reactions. The results of our calculation are compared to measurements of the (anti-)hyperon yields at midrapidity ($\mid$y$\mid$ $\leq$ 0.5) and total multiplicities performed by the NA49 and NA57 Collaborations at 40$A$ and 158$A$ GeV. Furthermore, we compared our predictions to the centrality dependence of $\Lambda$, $\bar{\Lambda}$ and $\Xi^{-}$ rapidity spectra and total multiplicities at 40$A$ and 158$A$ GeV, where possible.
[ { "created": "Mon, 2 Mar 2009 22:08:15 GMT", "version": "v1" }, { "created": "Wed, 18 Nov 2009 10:13:30 GMT", "version": "v2" } ]
2013-05-29
[ [ "Petersen", "Hannah", "" ], [ "Mitrovski", "Michael", "" ], [ "Schuster", "Tim", "" ], [ "Bleicher", "Marcus", "" ] ]
We present results on the centrality and system size dependence of (multi-strange)hyperons in Pb+Pb collisions at 40$A$ and 158$A$ GeV from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD-v2.3) model and a coupled Boltzmann+hydrodynamics calculation. The second approach is realized in a hybrid fashion based on UrQMD with an intermediate hydrodynamical evolution for the hot and dense stage of the collision. This implementation allows a comparison of microscopic transport calculations with hydrodynamic simulations to explore the transition from a system that is not fully equilibrated such as C+C or Si+Si collisions, to a supposedly fully equilibrated system, such as that created in Pb+Pb reactions. The results of our calculation are compared to measurements of the (anti-)hyperon yields at midrapidity ($\mid$y$\mid$ $\leq$ 0.5) and total multiplicities performed by the NA49 and NA57 Collaborations at 40$A$ and 158$A$ GeV. Furthermore, we compared our predictions to the centrality dependence of $\Lambda$, $\bar{\Lambda}$ and $\Xi^{-}$ rapidity spectra and total multiplicities at 40$A$ and 158$A$ GeV, where possible.
1405.2324
Narayan Rana
Taushif Ahmed, Maguni Mahakhud, Prakash Mathews, Narayan Rana and V. Ravindran
Two-Loop QCD Corrections to Higgs $\rightarrow b + \bar{b} + g$ Amplitude
Published version; 25 pages, 2 figures; v2: analytically continued result added, typos are corrected
JHEP 1408 (2014) 075
10.1007/JHEP08(2014)075
HRI-RECAPP-2014-010
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exclusive observables involving Higgs boson in association with jets are often well suited to study the Higgs boson properties. They are rates involving cuts on the final state jets or differential distributions of rapidity, transverse momentum of the observed Higgs boson. While they get dominant contributions from gluon initiated partonic subprocesses, it is important to include the subdominant ones coming from other channels. In this article, we study one such channel namely the Higgs production in association with a jet in bottom anti-bottom annihilation process. We compute relevant amplitude $H\rightarrow b+\overline b+g$ up to two loop level in QCD where Higgs couples to bottom quark through Yukawa coupling. We use projection operators to obtain the coefficients for each tensorial structure appearing in this process. We have demonstrated that the renormalized amplitudes do have the right infrared structure predicted by the QCD factorization in dimensional regularization. The finite parts of the one and two loop amplitudes are presented after subtracting the infrared poles using Catani's subtraction operators.
[ { "created": "Fri, 9 May 2014 19:24:49 GMT", "version": "v1" }, { "created": "Tue, 19 Aug 2014 19:23:44 GMT", "version": "v2" } ]
2014-08-20
[ [ "Ahmed", "Taushif", "" ], [ "Mahakhud", "Maguni", "" ], [ "Mathews", "Prakash", "" ], [ "Rana", "Narayan", "" ], [ "Ravindran", "V.", "" ] ]
Exclusive observables involving Higgs boson in association with jets are often well suited to study the Higgs boson properties. They are rates involving cuts on the final state jets or differential distributions of rapidity, transverse momentum of the observed Higgs boson. While they get dominant contributions from gluon initiated partonic subprocesses, it is important to include the subdominant ones coming from other channels. In this article, we study one such channel namely the Higgs production in association with a jet in bottom anti-bottom annihilation process. We compute relevant amplitude $H\rightarrow b+\overline b+g$ up to two loop level in QCD where Higgs couples to bottom quark through Yukawa coupling. We use projection operators to obtain the coefficients for each tensorial structure appearing in this process. We have demonstrated that the renormalized amplitudes do have the right infrared structure predicted by the QCD factorization in dimensional regularization. The finite parts of the one and two loop amplitudes are presented after subtracting the infrared poles using Catani's subtraction operators.
2307.03640
Gl\`oria Monta\~na Faiget
Gloria Montana, Angels Ramos, Laura Tolos and Juan M. Torres-Rincon
Recent progress on in-medium properties of heavy mesons from finite-temperature EFTs
16 pages, 8 figures, Submitted to Front.Phys.-Nuclear Physics to contribute to the Research Topic: Excotic Aspects of Hadrons and Nuclei
null
null
JLAB-THY-23-3874
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mesons with heavy flavor content are an exceptional probe of the hot QCD medium produced in heavy-ion collisions. In the past few years, significant progress has been made toward describing the modification of the properties of heavy mesons in the hadronic phase at finite temperature. Ground-state and excited-state thermal spectral properties can be computed within a self-consistent many-body approach that employs appropriate hadron-hadron effective interactions, providing a unique opportunity to confront hadronic Effective Field Theory predictions with recent and forthcoming lattice QCD simulations and experimental data. In this article, we revisit the application of the imaginary-time formalism to extend the calculation of unitarized scattering amplitudes from the vacuum to finite temperature. These methods allow us to obtain the ground-state thermal spectral functions. The thermal properties of the excited states that are dynamically generated within the molecular picture are also directly accessible. We present here the results of this approach for the open-charm and open-bottom sectors. We also analyze how the heavy-flavor transport properties, which are strongly correlated to experimental observables in heavy-ion collisions, are modified in hot matter. In particular, transport coefficients can be computed using an off-shell kinetic theory that is fully consistent with the effective theory describing the scattering processes. The results of this procedure for both charm and bottom transport coefficients are briefly discussed.
[ { "created": "Fri, 7 Jul 2023 15:01:59 GMT", "version": "v1" } ]
2023-07-10
[ [ "Montana", "Gloria", "" ], [ "Ramos", "Angels", "" ], [ "Tolos", "Laura", "" ], [ "Torres-Rincon", "Juan M.", "" ] ]
Mesons with heavy flavor content are an exceptional probe of the hot QCD medium produced in heavy-ion collisions. In the past few years, significant progress has been made toward describing the modification of the properties of heavy mesons in the hadronic phase at finite temperature. Ground-state and excited-state thermal spectral properties can be computed within a self-consistent many-body approach that employs appropriate hadron-hadron effective interactions, providing a unique opportunity to confront hadronic Effective Field Theory predictions with recent and forthcoming lattice QCD simulations and experimental data. In this article, we revisit the application of the imaginary-time formalism to extend the calculation of unitarized scattering amplitudes from the vacuum to finite temperature. These methods allow us to obtain the ground-state thermal spectral functions. The thermal properties of the excited states that are dynamically generated within the molecular picture are also directly accessible. We present here the results of this approach for the open-charm and open-bottom sectors. We also analyze how the heavy-flavor transport properties, which are strongly correlated to experimental observables in heavy-ion collisions, are modified in hot matter. In particular, transport coefficients can be computed using an off-shell kinetic theory that is fully consistent with the effective theory describing the scattering processes. The results of this procedure for both charm and bottom transport coefficients are briefly discussed.
hep-ph/9506354
null
K. S. Babu and R. N. Mohapatra
New vector-scalar contributions to neutrinoless double beta decay and constraints on R-parity violation
Latex file; 9 pages; 3 figures available on request
Phys.Rev.Lett.75:2276-2279,1995
10.1103/PhysRevLett.75.2276
null
hep-ph
null
We show that in minimal supersymmetric standard model (MSSM) with R-parity breaking as well as in the left-right symmetric model, there are new observable contributions to neutrinoless double beta decay arising from hitherto overlooked diagrams involving the exchange of one W boson and one scalar boson. In particular, in the case of MSSM, the present experimental bounds on neutrinoless double beta decay lifetime improves the limits on certain R-parity violating couplings by about two orders of magnitude. It is shown that similar diagrams also lead to enhanced rates for $\mu^-\rightarrow e^+$ conversion in nuclei, which are in the range accessible to ongoing experiments.
[ { "created": "Sun, 18 Jun 1995 00:13:34 GMT", "version": "v1" } ]
2011-05-12
[ [ "Babu", "K. S.", "" ], [ "Mohapatra", "R. N.", "" ] ]
We show that in minimal supersymmetric standard model (MSSM) with R-parity breaking as well as in the left-right symmetric model, there are new observable contributions to neutrinoless double beta decay arising from hitherto overlooked diagrams involving the exchange of one W boson and one scalar boson. In particular, in the case of MSSM, the present experimental bounds on neutrinoless double beta decay lifetime improves the limits on certain R-parity violating couplings by about two orders of magnitude. It is shown that similar diagrams also lead to enhanced rates for $\mu^-\rightarrow e^+$ conversion in nuclei, which are in the range accessible to ongoing experiments.
hep-ph/9609270
Lu Gong Ru
Zhenjun Xiao, Shunmin Liu, Xuelei Wang, Lingde Wan and Gongru Lu
Precision Data and Implications on the Parameters of TC theory
10 pages, Latex, no macros, no figures, hard copy is available upon request. to appear in Commun.Theor.Phys
Commun.Theor.Phys. 29 (1998) 431-436
null
HNU-TH-96/5
hep-ph
null
Assuming that the actual values of $m_t$ and the data set ($\Gamma_b$, $\Gamma_h$, $\Gamma_Z$, $R_b$, $R_c$, $R_l$) are within their $1-\sigma$ errors as reported by CDF, D0 and by LEP Collaborations, the parameter $\Delta^{new}_b$ which measures the nonoblique corrections on the $Zb\overline{b}$ vertex from new physics can be determined experimentally. According to the precision data one can obtain updated constraints on the parameters $\xi$ and the masses of the charged PGBs.
[ { "created": "Fri, 6 Sep 1996 16:05:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Xiao", "Zhenjun", "" ], [ "Liu", "Shunmin", "" ], [ "Wang", "Xuelei", "" ], [ "Wan", "Lingde", "" ], [ "Lu", "Gongru", "" ] ]
Assuming that the actual values of $m_t$ and the data set ($\Gamma_b$, $\Gamma_h$, $\Gamma_Z$, $R_b$, $R_c$, $R_l$) are within their $1-\sigma$ errors as reported by CDF, D0 and by LEP Collaborations, the parameter $\Delta^{new}_b$ which measures the nonoblique corrections on the $Zb\overline{b}$ vertex from new physics can be determined experimentally. According to the precision data one can obtain updated constraints on the parameters $\xi$ and the masses of the charged PGBs.
1611.07844
Agnes Roberts
\'Agnes Roberts
New Searches for CPT Violation in Neutral-Meson Oscillations
Presented at the Seventh Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 20-24, 2016
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Classic tests of CPT symmetry have been done in the neutral-meson system. These have been continued with new results in the framework of the Standard-Model Extension, where the coefficient for CPT violation is both boost and direction dependent. Recent contributions and new phenomenological improvements are discussed with possible new contributions for $b$ and $d$ specific correlated decays at the Belle II asymmetric energy collider.
[ { "created": "Sun, 16 Oct 2016 16:32:02 GMT", "version": "v1" } ]
2016-11-24
[ [ "Roberts", "Ágnes", "" ] ]
Classic tests of CPT symmetry have been done in the neutral-meson system. These have been continued with new results in the framework of the Standard-Model Extension, where the coefficient for CPT violation is both boost and direction dependent. Recent contributions and new phenomenological improvements are discussed with possible new contributions for $b$ and $d$ specific correlated decays at the Belle II asymmetric energy collider.
1911.11254
Thomas Rueter
Thomas D. Rueter, Thomas G. Rizzo, JoAnne L. Hewett
Dark Matter Freeze Out with Tsallis Statistics in the Early Universe
19 pages, 9 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The nature of dark matter (DM) and how it might interact with the particles of the Standard Model (SM) is one of greatest mysteries currently facing particle physics, and addressing these issues should provide some understanding of how the observed relic abundance was produced. One widely considered production mechanism, a weakly interacting massive particle (WIMP) produced as a thermal relic, provides a target cross section for DM annihilation into SM particles by solving the Boltzmann equation. In this thermal freeze-out mechanism, dark matter is produced in thermal equilibrium with the SM in the early universe, and drops out of equilibrium to its observed abundance as the universe cools and expands. In this paper, we study the impact of a generalized thermodynamics, known as Tsallis statistics and governed by a parameter $q$, on the target DM annihilation cross section. We derive the phase space distributions of particles in this generalized statistical framework, and check their thermodynamic consistency, as well as analyzing the impact of this generalization on the collisional term of the Boltzmann equation. We consider the case of an initial value of $q_0>1$, with $q$ relaxing to 1 as the universe expands and cools, and solve the generalized Boltzmann numerically for several benchmark DM masses, finding the corresponding target annihilation cross sections as a function of $q_0$. We find that as $q$ departs from the standard thermodynamic case of $q=1$, the collisional term falls less slowly as a function of $x = m_\chi/T$ than expected in the standard case. We also find that the target cross section falls sharply from $\sigma v \simeq 2.2-2.6\times10^{-26} \textrm{cm}^3/\textrm{s}$ for $q_0=1$ to, for example, $\sigma v \simeq 3\times 10^{-34} \textrm{cm}^3/\textrm{s}$ for $q_0=1.05$ for a 100 GeV WIMP.
[ { "created": "Mon, 25 Nov 2019 22:03:34 GMT", "version": "v1" }, { "created": "Wed, 14 Oct 2020 16:28:36 GMT", "version": "v2" } ]
2020-10-15
[ [ "Rueter", "Thomas D.", "" ], [ "Rizzo", "Thomas G.", "" ], [ "Hewett", "JoAnne L.", "" ] ]
The nature of dark matter (DM) and how it might interact with the particles of the Standard Model (SM) is one of greatest mysteries currently facing particle physics, and addressing these issues should provide some understanding of how the observed relic abundance was produced. One widely considered production mechanism, a weakly interacting massive particle (WIMP) produced as a thermal relic, provides a target cross section for DM annihilation into SM particles by solving the Boltzmann equation. In this thermal freeze-out mechanism, dark matter is produced in thermal equilibrium with the SM in the early universe, and drops out of equilibrium to its observed abundance as the universe cools and expands. In this paper, we study the impact of a generalized thermodynamics, known as Tsallis statistics and governed by a parameter $q$, on the target DM annihilation cross section. We derive the phase space distributions of particles in this generalized statistical framework, and check their thermodynamic consistency, as well as analyzing the impact of this generalization on the collisional term of the Boltzmann equation. We consider the case of an initial value of $q_0>1$, with $q$ relaxing to 1 as the universe expands and cools, and solve the generalized Boltzmann numerically for several benchmark DM masses, finding the corresponding target annihilation cross sections as a function of $q_0$. We find that as $q$ departs from the standard thermodynamic case of $q=1$, the collisional term falls less slowly as a function of $x = m_\chi/T$ than expected in the standard case. We also find that the target cross section falls sharply from $\sigma v \simeq 2.2-2.6\times10^{-26} \textrm{cm}^3/\textrm{s}$ for $q_0=1$ to, for example, $\sigma v \simeq 3\times 10^{-34} \textrm{cm}^3/\textrm{s}$ for $q_0=1.05$ for a 100 GeV WIMP.
1306.2500
Sushant Raut
Monojit Ghosh, Pomita Ghoshal, Srubabati Goswami, Sushant K. Raut
Can atmospheric neutrino experiments provide the first hint of leptonic CP violation?
5 pages, 4 figures. Version accepted for publication in Phys. Rev. D (Rapid Communication)
null
10.1103/PhysRevD.89.011301
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The measurement of a non-zero value of the 1-3 mixing angle has paved the way for the determination of leptonic CP violation. However the current generation long-baseline experiments T2K and NOvA have limited sensitivity to delta_{CP}. In this paper we show for the first time, the significance of that atmospheric neutrino experiments in providing the first hint of CP violation in conjunction with T2K and NOvA. In particular, we find that adding atmospheric neutrino data from the ICAL detector at the India-based Neutrino Observatory (INO) to T2K and NOvA results in a two-fold increase in the range of delta_{CP} values for which a 2 sigma hint of CP violation can be obtained. In fact in the parameter region unfavorable for the latter experiments, the first signature of CP violation may well come from the inclusion of atmospheric neutrino data.
[ { "created": "Tue, 11 Jun 2013 12:27:32 GMT", "version": "v1" }, { "created": "Thu, 27 Jun 2013 11:40:45 GMT", "version": "v2" }, { "created": "Fri, 28 Jun 2013 13:13:54 GMT", "version": "v3" }, { "created": "Wed, 4 Dec 2013 11:16:15 GMT", "version": "v4" } ]
2014-01-22
[ [ "Ghosh", "Monojit", "" ], [ "Ghoshal", "Pomita", "" ], [ "Goswami", "Srubabati", "" ], [ "Raut", "Sushant K.", "" ] ]
The measurement of a non-zero value of the 1-3 mixing angle has paved the way for the determination of leptonic CP violation. However the current generation long-baseline experiments T2K and NOvA have limited sensitivity to delta_{CP}. In this paper we show for the first time, the significance of that atmospheric neutrino experiments in providing the first hint of CP violation in conjunction with T2K and NOvA. In particular, we find that adding atmospheric neutrino data from the ICAL detector at the India-based Neutrino Observatory (INO) to T2K and NOvA results in a two-fold increase in the range of delta_{CP} values for which a 2 sigma hint of CP violation can be obtained. In fact in the parameter region unfavorable for the latter experiments, the first signature of CP violation may well come from the inclusion of atmospheric neutrino data.
hep-ph/9912415
Fyodor V. Tkachov
D.Yu.Grigoriev and F.V.Tkachov (INR, Moscow)
An efficient implementation of the optimal jet definition
5p PS; corrections 2001-08: normalization of Y; code at http://www.inr.ac.ru/~ftkachov/projects/jets/
null
null
null
hep-ph hep-ex
null
We describe an efficient implementation of the optimal jet definition derived in hep-ph/9901444 (revision of January, 2000) and implemented in Fortran 77. The algorithm handles both c.m.s. and hadron collision kinematics.
[ { "created": "Sun, 19 Dec 1999 16:40:36 GMT", "version": "v1" }, { "created": "Sat, 8 Jan 2000 09:42:08 GMT", "version": "v2" }, { "created": "Thu, 16 Aug 2001 03:46:58 GMT", "version": "v3" } ]
2007-05-23
[ [ "Grigoriev", "D. Yu.", "", "INR, Moscow" ], [ "Tkachov", "F. V.", "", "INR, Moscow" ] ]
We describe an efficient implementation of the optimal jet definition derived in hep-ph/9901444 (revision of January, 2000) and implemented in Fortran 77. The algorithm handles both c.m.s. and hadron collision kinematics.
1312.2887
Alexandr Panin
Dmitry Gorbunov, Alexander Panin
On the minimal active-sterile neutrino mixing in seesaw type I mechanism with sterile neutrinos at GeV scale
7 pages, 2 figures
Phys. Rev. D 89, 017302 (2014)
10.1103/PhysRevD.89.017302
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Renewed interest in GeV-scale sterile neutrinos capable of explaining active neutrino oscillations via see-saw type I mechanism has been expressed in several proposals of direct searches. Given this activity we estimate the minimal values of sterile-active mixing angles provided one, two, or three sterile neutrinos are lighter than D-meson.
[ { "created": "Tue, 10 Dec 2013 17:22:42 GMT", "version": "v1" } ]
2014-02-05
[ [ "Gorbunov", "Dmitry", "" ], [ "Panin", "Alexander", "" ] ]
Renewed interest in GeV-scale sterile neutrinos capable of explaining active neutrino oscillations via see-saw type I mechanism has been expressed in several proposals of direct searches. Given this activity we estimate the minimal values of sterile-active mixing angles provided one, two, or three sterile neutrinos are lighter than D-meson.
hep-ph/0402086
Tianjun Li
Junhai Kang, Paul Langacker, Tianjun Li, Tao Liu
Electroweak Baryogenesis in a Supersymmetric U(1)' Model
RevTex, 4 pages, 2 figures, references added, version to appear in PRL
Phys.Rev.Lett. 94 (2005) 061801
10.1103/PhysRevLett.94.061801
null
hep-ph astro-ph
null
We construct an anomaly free supersymmetric U(1)' model with a secluded U(1)'-breaking sector. We study the one-loop effective potential at finite temperature, and show that there exists a strong enough first order electroweak phase transition for electroweak baryogenesis (EWBG) because of the large trilinear term $A_h h S H_d H_u$ in the tree-level Higgs potential. Unlike in the MSSM, the lightest stop can be very heavy. We consider the non-local EWBG mechanism in the thin wall regime, and find that within uncertainties the observed baryon number can be generated from the $\tau$ lepton contribution, with the secluded sector playing an essential role. The chargino and neutralino contributions and the implications for the Z' mass and electric dipole moments are briefly discussed.
[ { "created": "Mon, 9 Feb 2004 02:22:02 GMT", "version": "v1" }, { "created": "Thu, 20 Jan 2005 21:59:02 GMT", "version": "v2" } ]
2016-09-06
[ [ "Kang", "Junhai", "" ], [ "Langacker", "Paul", "" ], [ "Li", "Tianjun", "" ], [ "Liu", "Tao", "" ] ]
We construct an anomaly free supersymmetric U(1)' model with a secluded U(1)'-breaking sector. We study the one-loop effective potential at finite temperature, and show that there exists a strong enough first order electroweak phase transition for electroweak baryogenesis (EWBG) because of the large trilinear term $A_h h S H_d H_u$ in the tree-level Higgs potential. Unlike in the MSSM, the lightest stop can be very heavy. We consider the non-local EWBG mechanism in the thin wall regime, and find that within uncertainties the observed baryon number can be generated from the $\tau$ lepton contribution, with the secluded sector playing an essential role. The chargino and neutralino contributions and the implications for the Z' mass and electric dipole moments are briefly discussed.
hep-ph/9806531
Kosuke Odagiri
K. Odagiri (Cavendish Laboratory, Cambridge, UK)
Colour connection structure of (supersymmetric) QCD ($2\to2$) processes
12 pages, 4 figures, LaTeX2e
JHEP 9810:006,1998
10.1088/1126-6708/1998/10/006
Cavendish-HEP-98/05
hep-ph
null
The colour connection structure of QCD ($2\to2$) processes is discussed, with emphasis on its application to the supersymmetric 2 parton $\to$ 2 sparton processes, which are currently being implemented in the HERWIG Monte Carlo event generator. The procedure described by Marchesini and Webber is found to be inadequate, and a new method is proposed. However, this alteration is unlikely to significantly affect the theoretical predictions for soft gluon radiation. A complete list of supersymmetric QCD $2\to2$ matrix elements and their colour decompositions is presented.
[ { "created": "Tue, 30 Jun 1998 15:44:09 GMT", "version": "v1" }, { "created": "Wed, 10 Feb 1999 16:40:46 GMT", "version": "v2" } ]
2010-02-03
[ [ "Odagiri", "K.", "", "Cavendish Laboratory, Cambridge, UK" ] ]
The colour connection structure of QCD ($2\to2$) processes is discussed, with emphasis on its application to the supersymmetric 2 parton $\to$ 2 sparton processes, which are currently being implemented in the HERWIG Monte Carlo event generator. The procedure described by Marchesini and Webber is found to be inadequate, and a new method is proposed. However, this alteration is unlikely to significantly affect the theoretical predictions for soft gluon radiation. A complete list of supersymmetric QCD $2\to2$ matrix elements and their colour decompositions is presented.
0807.2922
Gilberto Ramalho
G. Ramalho and M.T. Pena
Electromagnetic form factors of the Delta in a S-wave approach
11 pages, 3 figures
J.Phys.G36:085004,2009
10.1088/0954-3899/36/8/085004
JLAB-THY-08-857
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Without any further adjusting of parameters, a relativistic constituent quark model, successful in the description of the data for the nucleon elastic form factors and of the dominant contribution for the nucleon to Delta electromagnetic transition, is used here to predict the dominant electromagnetic form factors of the Delta baryon. The model is based on a simple Delta wave function corresponding to a quark-diquark system in an S-state. The results for E0 and M1 are consistent both with experimental results and lattice calculations. The remaining form factors E2 and M3 vanish, given the symmetric structure taken for the Delta.
[ { "created": "Fri, 18 Jul 2008 19:46:10 GMT", "version": "v1" }, { "created": "Thu, 21 Aug 2008 17:53:28 GMT", "version": "v2" }, { "created": "Thu, 4 Jun 2009 16:41:37 GMT", "version": "v3" } ]
2009-07-24
[ [ "Ramalho", "G.", "" ], [ "Pena", "M. T.", "" ] ]
Without any further adjusting of parameters, a relativistic constituent quark model, successful in the description of the data for the nucleon elastic form factors and of the dominant contribution for the nucleon to Delta electromagnetic transition, is used here to predict the dominant electromagnetic form factors of the Delta baryon. The model is based on a simple Delta wave function corresponding to a quark-diquark system in an S-state. The results for E0 and M1 are consistent both with experimental results and lattice calculations. The remaining form factors E2 and M3 vanish, given the symmetric structure taken for the Delta.
1504.00749
Masatoshi Yamada
Ken-Ichi Aoki and Masatoshi Yamada
The RG flow of Nambu--Jona-Lasinio model at finite temperature and density
14 pages, 5 figures, published version
Int. J. Mod. Phys. A 30, 1550180 (2015)
10.1142/S0217751X15501808
KANAZAWA-15-03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Nambu--Jona-Lasinio model at finite temperature and finite density by using the functional renormalization group. The RG flows of the four-fermi coupling constant in the NJL model are investigated. We obtain the chiral phase boundary in cases of the large-$N$ leading approximation and an improved approximation. The large-$N$ non-leading term at the vanishing temperature has a singularity at the fermi surface. We show that the quantum corrections by the large-$N$ non-leading term largely influence the phase boundary at the low temperature and high density region.
[ { "created": "Fri, 3 Apr 2015 05:44:19 GMT", "version": "v1" }, { "created": "Fri, 2 Oct 2015 11:19:55 GMT", "version": "v2" } ]
2015-10-05
[ [ "Aoki", "Ken-Ichi", "" ], [ "Yamada", "Masatoshi", "" ] ]
We study the Nambu--Jona-Lasinio model at finite temperature and finite density by using the functional renormalization group. The RG flows of the four-fermi coupling constant in the NJL model are investigated. We obtain the chiral phase boundary in cases of the large-$N$ leading approximation and an improved approximation. The large-$N$ non-leading term at the vanishing temperature has a singularity at the fermi surface. We show that the quantum corrections by the large-$N$ non-leading term largely influence the phase boundary at the low temperature and high density region.
hep-ph/9712363
Michael Kachelriess
M. Kachelriess
Neutrino self-energy and pair creation in neutron stars
9 pages, latex2e, 1 figure
Phys.Lett. B426 (1998) 89-94
10.1016/S0370-2693(98)00076-8
null
hep-ph
null
Massless neutrino exchange leads to a new long-range force between matter. Recently, it was claimed both that the potential energy due to this interaction i) dominates the total energy of neutron stars and ii) that it is zero. We recalculate the energy of a neutrino propagating in a classical, uniform background of neutrons and find a negligible, but non-zero contribution to the total energy of neutron stars. We estimate the neutrino pair creation rate of a neutron star caused by a density gradient of the background neutrons but found it too small to be observable.
[ { "created": "Fri, 12 Dec 1997 18:03:46 GMT", "version": "v1" } ]
2009-10-30
[ [ "Kachelriess", "M.", "" ] ]
Massless neutrino exchange leads to a new long-range force between matter. Recently, it was claimed both that the potential energy due to this interaction i) dominates the total energy of neutron stars and ii) that it is zero. We recalculate the energy of a neutrino propagating in a classical, uniform background of neutrons and find a negligible, but non-zero contribution to the total energy of neutron stars. We estimate the neutrino pair creation rate of a neutron star caused by a density gradient of the background neutrons but found it too small to be observable.
hep-ph/0010070
Badri Magradze
B.A. Magradze (Joint Institute for Nuclear Research, Dubna, and A. Razmadze Mathematical Institute, Tbilisi.)
QCD coupling up to third order in standard and analytic perturbation theories
21 pages, Latex, 12 tables. Abstract is changed. The recurrence formulas (18)-(20) are added. Formula (35) corrected and Table 2 is revised. Misprint in formula (37) is corrected. Formula (38) added
Communication of the Joint Institute for Nuclear Research, E2-2000-222, Dubna 2000
null
RMI-000-45
hep-ph
null
We analyze two sets of specific functions, that/which form the basis of the nonpower asymptotic expansions both in the timelike and spacelike regions for single scale dependent QCD observables in the Shirkov--Solovtsov's Analytic Perturbation Theory (APT) free of unphysical singularities. These functions are explicitly derived up to the third order in the closed form in terms of the Lambert-W function. As an input we used the exact two loop and the three loop (corresponding to Pad\'e transformed beta-function) RG solutions for common invariant coupling \alpha_s. The elegant recurrence formulas, helpful for numerical analysis, are obtained for the both sets of the APT functions. Then we construct the global versions of APT functions using the continuity conditions (at the quark thresholds) on the \alpha_s in the \bar{MS} scheme and give numerical results. For first three of these functions \mathfrak{A}_n(s) and {\cal A}_n(Q^2); n=1,2,3 in the large interval of the momentum transfer and energy (1 GeV <Q,{\sqrt s}< 170 GeV), numerical tables are presented. From these we observe that, for the timelike arguments, the differences between functions \mathfrak{A}_n(s) and the corresponding powers of the standard iteratively approximated coupling \alpha_s^n(s) are not negligible even for moderate energies in the five--flavor region.
[ { "created": "Sun, 8 Oct 2000 12:45:27 GMT", "version": "v1" }, { "created": "Thu, 9 Nov 2000 11:27:40 GMT", "version": "v2" }, { "created": "Tue, 14 Nov 2000 15:25:12 GMT", "version": "v3" }, { "created": "Sun, 7 Jan 2001 12:58:19 GMT", "version": "v4" } ]
2007-05-23
[ [ "Magradze", "B. A.", "", "Joint Institute for Nuclear Research, Dubna, and A.\n Razmadze Mathematical Institute, Tbilisi." ] ]
We analyze two sets of specific functions, that/which form the basis of the nonpower asymptotic expansions both in the timelike and spacelike regions for single scale dependent QCD observables in the Shirkov--Solovtsov's Analytic Perturbation Theory (APT) free of unphysical singularities. These functions are explicitly derived up to the third order in the closed form in terms of the Lambert-W function. As an input we used the exact two loop and the three loop (corresponding to Pad\'e transformed beta-function) RG solutions for common invariant coupling \alpha_s. The elegant recurrence formulas, helpful for numerical analysis, are obtained for the both sets of the APT functions. Then we construct the global versions of APT functions using the continuity conditions (at the quark thresholds) on the \alpha_s in the \bar{MS} scheme and give numerical results. For first three of these functions \mathfrak{A}_n(s) and {\cal A}_n(Q^2); n=1,2,3 in the large interval of the momentum transfer and energy (1 GeV <Q,{\sqrt s}< 170 GeV), numerical tables are presented. From these we observe that, for the timelike arguments, the differences between functions \mathfrak{A}_n(s) and the corresponding powers of the standard iteratively approximated coupling \alpha_s^n(s) are not negligible even for moderate energies in the five--flavor region.
2103.04974
Giancarlo Ferrera
Stefano Camarda, Leandro Cieri and Giancarlo Ferrera
Drell-Yan lepton-pair production: $q_T$ resummation at N$^3$LL accuracy and fiducial cross sections at N$^3$LO
17 pages, 3 figures. Slightly expanded text, figure and references added, results unchanged. Version published on PRD
null
10.1103/PhysRevD.104.L111503
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present high-accuracy QCD predictions for the transverse-momentum ($q_T$) distribution and fiducial cross sections of Drell-Yan lepton pairs produced in hadronic collisions. At small value of $q_T$ we resum to all perturbative orders the logarithmically enhanced contributions up to next-to-next-to-next-to-leading logarithmic (N$^3$LL) accuracy, including all the next-to-next-to-next-to-leading order (N$^3$LO) (i.e. $\mathcal{O}(\alpha_S^3)$) terms. Our resummed calculation has been implemented in the public numerical program DYTurbo, which produces fast and precise predictions with the full dependence on the final-state leptons kinematics. We consistently combine our resummed results with the known $\mathcal{O}(\alpha_S^3)$ fixed-order predictions at large values of $q_T$ thus obtaining full N$^3$LO accuracy also for fiducial cross sections. We show numerical results at LHC energies discussing the reduction of the perturbative uncertainty with respect to lower-order calculations.
[ { "created": "Mon, 8 Mar 2021 18:52:05 GMT", "version": "v1" }, { "created": "Thu, 25 Mar 2021 15:57:40 GMT", "version": "v2" }, { "created": "Tue, 11 Jan 2022 13:13:08 GMT", "version": "v3" } ]
2022-01-12
[ [ "Camarda", "Stefano", "" ], [ "Cieri", "Leandro", "" ], [ "Ferrera", "Giancarlo", "" ] ]
We present high-accuracy QCD predictions for the transverse-momentum ($q_T$) distribution and fiducial cross sections of Drell-Yan lepton pairs produced in hadronic collisions. At small value of $q_T$ we resum to all perturbative orders the logarithmically enhanced contributions up to next-to-next-to-next-to-leading logarithmic (N$^3$LL) accuracy, including all the next-to-next-to-next-to-leading order (N$^3$LO) (i.e. $\mathcal{O}(\alpha_S^3)$) terms. Our resummed calculation has been implemented in the public numerical program DYTurbo, which produces fast and precise predictions with the full dependence on the final-state leptons kinematics. We consistently combine our resummed results with the known $\mathcal{O}(\alpha_S^3)$ fixed-order predictions at large values of $q_T$ thus obtaining full N$^3$LO accuracy also for fiducial cross sections. We show numerical results at LHC energies discussing the reduction of the perturbative uncertainty with respect to lower-order calculations.
2009.11996
Xi-Jie Zhan
Xi-Jie Zhan, Jian-Xiong Wang
Inclusive $\Upsilon(1S,2S,3S)$ photoproduction at the CEPC
Version accepted for publication in Chinese Physics C
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The inclusive $\Upsilon(1S,2S,3S)$ photoproduction at the future Circular-Electron-Positron-Collider (CEPC) is studied based on the non-relativistic QCD (NRQCD). Including the contributions from both direct and resolved photons, we present different distributions for $\Upsilon(1S,2S,3S)$ production and the results show there will be considerable events, which means that a well measurements on the $\Upsilon$ photoprodution could be performed to further study on the heavy quarkonium physics at electron-positron collider in addition to hadron colliders. This supplement study is very important to clarify the current situation of the heavy quarkonium production mechanism.
[ { "created": "Fri, 25 Sep 2020 01:38:58 GMT", "version": "v1" }, { "created": "Sun, 1 Nov 2020 11:01:44 GMT", "version": "v2" } ]
2020-11-03
[ [ "Zhan", "Xi-Jie", "" ], [ "Wang", "Jian-Xiong", "" ] ]
The inclusive $\Upsilon(1S,2S,3S)$ photoproduction at the future Circular-Electron-Positron-Collider (CEPC) is studied based on the non-relativistic QCD (NRQCD). Including the contributions from both direct and resolved photons, we present different distributions for $\Upsilon(1S,2S,3S)$ production and the results show there will be considerable events, which means that a well measurements on the $\Upsilon$ photoprodution could be performed to further study on the heavy quarkonium physics at electron-positron collider in addition to hadron colliders. This supplement study is very important to clarify the current situation of the heavy quarkonium production mechanism.
1303.2230
Dao-Neng Gao
Yi Sun, Hao-Ran Chang, Dao-Neng Gao
Higgs decays to gamma l+ l- in the standard model
16 pages, 9 figures. Typos corrected, references added
null
10.1007/JHEP05(2013)061
USTC-ICTS-12-15
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The radiative Higgs decays h -> gamma l+l- with l=e,mu and tau are analyzed in the standard model using m_h=125 GeV. Both tree and one-loop diagrams for the processes are evaluated. In addition to their decay rates and dilepton invariant mass distributions, we focus on the forward-back asymmetries in these modes. Our calculation shows that the forward-backward asymmetries in h -> gamma e+e- and h -> gamma mu+mu- could be up to 10^{-2} while in the tau+tau- final state, these asymmetries are below 1%. Thus the forward-backward asymmetries in h -> gamma l+l- might be interesting observables in the future precise experiments both to test our understanding of Higgs physics in the standard model and to probe the novel Higgs dynamics in new physics scenarios.
[ { "created": "Sat, 9 Mar 2013 16:30:10 GMT", "version": "v1" }, { "created": "Mon, 25 Mar 2013 09:58:50 GMT", "version": "v2" } ]
2015-06-15
[ [ "Sun", "Yi", "" ], [ "Chang", "Hao-Ran", "" ], [ "Gao", "Dao-Neng", "" ] ]
The radiative Higgs decays h -> gamma l+l- with l=e,mu and tau are analyzed in the standard model using m_h=125 GeV. Both tree and one-loop diagrams for the processes are evaluated. In addition to their decay rates and dilepton invariant mass distributions, we focus on the forward-back asymmetries in these modes. Our calculation shows that the forward-backward asymmetries in h -> gamma e+e- and h -> gamma mu+mu- could be up to 10^{-2} while in the tau+tau- final state, these asymmetries are below 1%. Thus the forward-backward asymmetries in h -> gamma l+l- might be interesting observables in the future precise experiments both to test our understanding of Higgs physics in the standard model and to probe the novel Higgs dynamics in new physics scenarios.
hep-ph/9412257
null
V.P. Gusynin, V.A. Miransky and I.A. Shovkovy
Dimensional Reduction and Dynamical Chiral Symmetry Breaking by a Magnetic Field in $3+1$ Dimensions
13 pages, LaTeX, no figures
Phys.Lett. B349 (1995) 477-483
10.1016/0370-2693(95)00232-A
Kiev-ITP-94-58E
hep-ph hep-th
null
It is shown that in $3+1$ dimensions, a constant magnetic field is a catalyst of dynamical chiral symmetry breaking, leading to generating a fermion mass even at the weakest attractive interaction between fermions. The essence of this effect is the dimensional reduction $D \rightarrow D-2$ ($3+1 \rightarrow 1+1$) in the dynamics of fermion pairing in a magnetic field. The effect is illustrated in the Nambu-Jona-Lasinio model. Possible applications of this effect are briefly discussed.
[ { "created": "Thu, 8 Dec 1994 08:44:14 GMT", "version": "v1" } ]
2019-08-15
[ [ "Gusynin", "V. P.", "" ], [ "Miransky", "V. A.", "" ], [ "Shovkovy", "I. A.", "" ] ]
It is shown that in $3+1$ dimensions, a constant magnetic field is a catalyst of dynamical chiral symmetry breaking, leading to generating a fermion mass even at the weakest attractive interaction between fermions. The essence of this effect is the dimensional reduction $D \rightarrow D-2$ ($3+1 \rightarrow 1+1$) in the dynamics of fermion pairing in a magnetic field. The effect is illustrated in the Nambu-Jona-Lasinio model. Possible applications of this effect are briefly discussed.
1705.00948
C. Q. Geng
Y.K. Hsiao and C.Q. Geng
Determinations of $|V_{cb}|$ and $|V_{ub}|$ from baryonic $\Lambda_b$ decays
8 pages, i figure
Eur. Phys. J. C77, 714 (2017)
10.1140/epjc/s10052-017-5271-1
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extract the Cabibbo-Kobayashi-Maskawa matrix element $V_{cb}$ from the exclusive decays of $\Lambda_b\to \Lambda_c\ell\bar \nu_\ell$ and $\Lambda_b\to \Lambda_c M_{(c)}$ with $M=(\pi^-,K^-)$ and $M_c=(D^-,D^-_s)$, where the branching ratios of $\Lambda_b\to \Lambda M_{(c)}$ measured with high precisions have not been used in the previous studies. Explicitly, we find $|V_{cb}|=(44.0\pm 3.5)\times 10^{-3}$, which agrees with the value of $(42.11\pm 0.74)\times 10^{-3}$ from the inclusive $B\to X_c\ell\bar \nu_\ell$ decays. Furthermore, based on the most recent ratio of $|V_{ub}|/|V_{cb}|$ from the exclusive $\Lambda_b$ decays, we obtain $|V_{ub}|=(4.2\pm 0.4)\times 10^{-3}$, which is close to the value of $(4.49\pm 0.24)\times 10^{-3}$ from the inclusive $B\to X_u\ell\bar \nu_\ell$ decays. We conclude that our determinations of $|V_{cb}|$ and $|V_{ub}|$ from the exclusive $\Lambda_b$ decays favor the inclusive extractions in the $B$ decays.
[ { "created": "Tue, 2 May 2017 13:06:29 GMT", "version": "v1" } ]
2017-11-02
[ [ "Hsiao", "Y. K.", "" ], [ "Geng", "C. Q.", "" ] ]
We extract the Cabibbo-Kobayashi-Maskawa matrix element $V_{cb}$ from the exclusive decays of $\Lambda_b\to \Lambda_c\ell\bar \nu_\ell$ and $\Lambda_b\to \Lambda_c M_{(c)}$ with $M=(\pi^-,K^-)$ and $M_c=(D^-,D^-_s)$, where the branching ratios of $\Lambda_b\to \Lambda M_{(c)}$ measured with high precisions have not been used in the previous studies. Explicitly, we find $|V_{cb}|=(44.0\pm 3.5)\times 10^{-3}$, which agrees with the value of $(42.11\pm 0.74)\times 10^{-3}$ from the inclusive $B\to X_c\ell\bar \nu_\ell$ decays. Furthermore, based on the most recent ratio of $|V_{ub}|/|V_{cb}|$ from the exclusive $\Lambda_b$ decays, we obtain $|V_{ub}|=(4.2\pm 0.4)\times 10^{-3}$, which is close to the value of $(4.49\pm 0.24)\times 10^{-3}$ from the inclusive $B\to X_u\ell\bar \nu_\ell$ decays. We conclude that our determinations of $|V_{cb}|$ and $|V_{ub}|$ from the exclusive $\Lambda_b$ decays favor the inclusive extractions in the $B$ decays.
1611.04598
Xiao-Ping Wang
Vedran Brdar, Joachim Kopp, Xiao-Ping Wang (MITP, Johannes Gutenberg University Mainz)
Sterile Neutrinos and Flavor Ratios in IceCube
15 pages, 6 figures; v2 matched to journal version
JCAP01(2017)026
10.1088/1475-7516/2017/01/026
MITP/16-116
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The flavor composition of astrophysical neutrinos observed in neutrino telescopes is a powerful discriminator between different astrophysical neutrino production mechanisms and can also teach us about the particle physics properties of neutrinos. In this paper, we investigate how the possible existence of light sterile neutrinos can affect these flavor ratios. We consider two scenarios: (i) neutrino production in conventional astrophysical sources, followed by partial oscillation into sterile states; (ii) neutrinos from dark matter decay with a primary flavor composition enhanced in tau neutrinos or sterile neutrinos. Throughout the paper, we constrain the sterile neutrino mixing parameters from a full global fit to short and long baseline data. We present our results in the form of flavor triangles and, for scenario (ii), as exclusion limits on the dark matter mass and lifetime, derived from a fit to IceCube high energy starting events and through-going muons. We argue that identifying a possible flux of neutrinos from dark matter decay may require analyzing the flavor composition as a function of neutrino energy.
[ { "created": "Mon, 14 Nov 2016 21:00:02 GMT", "version": "v1" }, { "created": "Tue, 17 Jan 2017 16:12:10 GMT", "version": "v2" } ]
2017-01-18
[ [ "Brdar", "Vedran", "", "MITP, Johannes Gutenberg\n University Mainz" ], [ "Kopp", "Joachim", "", "MITP, Johannes Gutenberg\n University Mainz" ], [ "Wang", "Xiao-Ping", "", "MITP, Johannes Gutenberg\n University Mainz" ] ]
The flavor composition of astrophysical neutrinos observed in neutrino telescopes is a powerful discriminator between different astrophysical neutrino production mechanisms and can also teach us about the particle physics properties of neutrinos. In this paper, we investigate how the possible existence of light sterile neutrinos can affect these flavor ratios. We consider two scenarios: (i) neutrino production in conventional astrophysical sources, followed by partial oscillation into sterile states; (ii) neutrinos from dark matter decay with a primary flavor composition enhanced in tau neutrinos or sterile neutrinos. Throughout the paper, we constrain the sterile neutrino mixing parameters from a full global fit to short and long baseline data. We present our results in the form of flavor triangles and, for scenario (ii), as exclusion limits on the dark matter mass and lifetime, derived from a fit to IceCube high energy starting events and through-going muons. We argue that identifying a possible flux of neutrinos from dark matter decay may require analyzing the flavor composition as a function of neutrino energy.
0804.4282
Bronislav Zakharov
P. Aurenche, B.G. Zakharov and H. Zaraket
Failure of the collinear expansion in calculation of the induced gluon emission
10 pages, 2 eps figures
JETP Lett.87:605-610,2008
10.1134/S0021364008110039
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate that the collinear expansion fails in the case of gluon emission from a fast quark produced in $eA$ DIS. In this approximation the N=1 rescattering contribution to the gluon spectrum vanishes. We show that the higher-twist approach by Guo, Wang and Zhang [4,5] based on the collinear expansion is wrong. The nonzero gluon spectrum obtained in [4,5] is a consequence of unjustified neglecting some important terms in the collinear expansion.
[ { "created": "Sun, 27 Apr 2008 14:25:35 GMT", "version": "v1" } ]
2009-02-19
[ [ "Aurenche", "P.", "" ], [ "Zakharov", "B. G.", "" ], [ "Zaraket", "H.", "" ] ]
We demonstrate that the collinear expansion fails in the case of gluon emission from a fast quark produced in $eA$ DIS. In this approximation the N=1 rescattering contribution to the gluon spectrum vanishes. We show that the higher-twist approach by Guo, Wang and Zhang [4,5] based on the collinear expansion is wrong. The nonzero gluon spectrum obtained in [4,5] is a consequence of unjustified neglecting some important terms in the collinear expansion.
0903.4869
Lisheng Geng
L.S. Geng, J. Martin Camalich, and M.J. Vicente Vacas
SU(3)-breaking corrections to the hyperon vector coupling $f_1(0)$ in covariant baryon chiral perturbation theory
13 pages, 5 figures
Phys.Rev.D79:094022,2009
10.1103/PhysRevD.79.094022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the SU(3)-breaking corrections to the hyperon vector coupling $f_1(0)$ up to $\mathcal{O}(p^4)$ in covariant baryon chiral perturbation theory with dynamical octet and decuplet contributions. We find that the decuplet contributions are of similar or even larger size than the octet ones. Combining both, we predict positive SU(3)-breaking corrections to all the four independent $f_1(0)$'s (assuming isospin symmetry), which are consistent, within uncertainties, with the latest results form large $N_c$ fits, chiral quark models, and quenched lattice QCD calculations.
[ { "created": "Fri, 27 Mar 2009 18:32:35 GMT", "version": "v1" } ]
2009-07-30
[ [ "Geng", "L. S.", "" ], [ "Camalich", "J. Martin", "" ], [ "Vacas", "M. J. Vicente", "" ] ]
We calculate the SU(3)-breaking corrections to the hyperon vector coupling $f_1(0)$ up to $\mathcal{O}(p^4)$ in covariant baryon chiral perturbation theory with dynamical octet and decuplet contributions. We find that the decuplet contributions are of similar or even larger size than the octet ones. Combining both, we predict positive SU(3)-breaking corrections to all the four independent $f_1(0)$'s (assuming isospin symmetry), which are consistent, within uncertainties, with the latest results form large $N_c$ fits, chiral quark models, and quenched lattice QCD calculations.
hep-ph/0507095
Ivan Schmidt
Ivan Schmidt
Shadowing and Antishadowing in Neutrino Deep Inelastic Scattering
4 pages, 1 figure, Prepared for the International Conference on QCD and Hadronic Physics, Beijing, China, June 16-20 2005
Int.J.Mod.Phys. A21 (2006) 942-945
10.1142/S0217751X0603237X
USM-TH-170
hep-ph
null
The coherence of multiscattering quark nuclear processes leads to shadowing and antishadowing of the electromagnetic nuclear structure functions in agreement with measurements. This picture leads to substantially different antishadowing for charged and neutral current processes, particularly in anti-neutrino reactions, thus affecting the extraction of the weak-mixing angle $\sin^2\theta_W$.
[ { "created": "Thu, 7 Jul 2005 20:13:05 GMT", "version": "v1" } ]
2009-11-11
[ [ "Schmidt", "Ivan", "" ] ]
The coherence of multiscattering quark nuclear processes leads to shadowing and antishadowing of the electromagnetic nuclear structure functions in agreement with measurements. This picture leads to substantially different antishadowing for charged and neutral current processes, particularly in anti-neutrino reactions, thus affecting the extraction of the weak-mixing angle $\sin^2\theta_W$.
1203.2068
Purnendu Chakraborty
Purnendu Chakraborty, Munshi G. Mustafa
D=2 gluon condensate and QCD propagators at finite temperature
Minor modifications. Accepted in PLB
null
10.1016/j.physletb.2012.04.030
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the dimension two gluon condensate contribution to quark, gluon and ghost propagators at finite temperature.
[ { "created": "Fri, 9 Mar 2012 13:02:26 GMT", "version": "v1" }, { "created": "Sat, 14 Apr 2012 02:46:36 GMT", "version": "v2" } ]
2015-06-04
[ [ "Chakraborty", "Purnendu", "" ], [ "Mustafa", "Munshi G.", "" ] ]
We calculate the dimension two gluon condensate contribution to quark, gluon and ghost propagators at finite temperature.
2406.03957
Ricardo Florentino
Ricardo R. Florentino, Shinya Kanemura, Masanori Tanaka
Exploring loop-induced first-order electroweak phase transition in the Higgs effective field theory
24 pages, 5 figures
null
null
OU-HET-1223
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
The nearly aligned Higgs Effective Field Theory (naHEFT) is based on the general assumption: all deviations in the Higgs boson couplings are originated from quantum one-loop effects of new particles that are integrated out. If the new particles integrated out have the same non-decoupling property, physics of the electroweak symmetry breaking can be then described by several parameters in the naHEFT, so that there is a correlation among the Higgs boson couplings such as $h \gamma \gamma$, $hWW$ and $hhh$ couplings. In this paper, we analyze the strongly first-order electroweak phase transition (EWPT) with the condition of sphaleron decoupling and the completion condition of the phase transition, and investigate the relation among the deviations in the Higgs boson couplings and the dynamics of the EWPTs. We also take into account the gravitational wave spectrum as well as the primordial black hole predicted at the EWPT. We show that if the new particles integrated out include charged scalar states future precision measurements of the $h \gamma \gamma$ coupling can give a useful prediction on the $hhh$ coupling to realize the strongly first-order EWPT. We can explore the nature of EWPT and the new physics behind it by the combination of precision measurements of various Higgs boson couplings at future collider experiments, gravitational wave observations at future space-based interferometers and searches for primordial black holes.
[ { "created": "Thu, 6 Jun 2024 11:04:35 GMT", "version": "v1" } ]
2024-06-07
[ [ "Florentino", "Ricardo R.", "" ], [ "Kanemura", "Shinya", "" ], [ "Tanaka", "Masanori", "" ] ]
The nearly aligned Higgs Effective Field Theory (naHEFT) is based on the general assumption: all deviations in the Higgs boson couplings are originated from quantum one-loop effects of new particles that are integrated out. If the new particles integrated out have the same non-decoupling property, physics of the electroweak symmetry breaking can be then described by several parameters in the naHEFT, so that there is a correlation among the Higgs boson couplings such as $h \gamma \gamma$, $hWW$ and $hhh$ couplings. In this paper, we analyze the strongly first-order electroweak phase transition (EWPT) with the condition of sphaleron decoupling and the completion condition of the phase transition, and investigate the relation among the deviations in the Higgs boson couplings and the dynamics of the EWPTs. We also take into account the gravitational wave spectrum as well as the primordial black hole predicted at the EWPT. We show that if the new particles integrated out include charged scalar states future precision measurements of the $h \gamma \gamma$ coupling can give a useful prediction on the $hhh$ coupling to realize the strongly first-order EWPT. We can explore the nature of EWPT and the new physics behind it by the combination of precision measurements of various Higgs boson couplings at future collider experiments, gravitational wave observations at future space-based interferometers and searches for primordial black holes.
0704.1710
Kazuya Mitsutani
Kazuya Mitsutani, Masakiyo Kitazawa, Teiji Kunihiro, Yukio Nemoto
Further Analysis of Excitations of Quarks at Finite Temperature -- Mass Effect and Pole Structure --
6pages, 5 figures. Poster presentation at the 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM2006) held in Shanghai, China on November 14-20, 2006
Int.J.Mod.Phys.E16:2263-2268,2007
10.1142/S0218301307007787
YITP-07-19
hep-ph
null
We calculate the spectral function of the massive quark at finite temperature (T) using a Yukawa model and show that the peak in the negative energy region among the three-peaks found in a previous work for the massless quark is largely suppressed. To explore the underlying mechanism of this behavior, we also investigate the pole structure of the retarded Green function of the quark. We will show the result only for the massless quark. We find the residues of the poles corresponding the three-peaks are all comparable at $T\sim m_b$. We also show that the multi-peak structure of the quark spectra is well described in the pole approximation which indicates that the quasi-paricle picture is valid in this $T$ region.
[ { "created": "Fri, 13 Apr 2007 07:43:05 GMT", "version": "v1" } ]
2010-11-26
[ [ "Mitsutani", "Kazuya", "" ], [ "Kitazawa", "Masakiyo", "" ], [ "Kunihiro", "Teiji", "" ], [ "Nemoto", "Yukio", "" ] ]
We calculate the spectral function of the massive quark at finite temperature (T) using a Yukawa model and show that the peak in the negative energy region among the three-peaks found in a previous work for the massless quark is largely suppressed. To explore the underlying mechanism of this behavior, we also investigate the pole structure of the retarded Green function of the quark. We will show the result only for the massless quark. We find the residues of the poles corresponding the three-peaks are all comparable at $T\sim m_b$. We also show that the multi-peak structure of the quark spectra is well described in the pole approximation which indicates that the quasi-paricle picture is valid in this $T$ region.
hep-ph/0107224
Martin McDermott
M. McDermott, R. Sandapen and G. Shaw
Colour dipoles and virtual Compton scattering
Published version, 27 pages, 17 figures. Several minor changes made in response to the referee's comments: discussion concerning the azimuthal angle phi and the large Q^2 limit made more precise, two figures added to compare the transverse size profiles for DVCS and DIS. Eq.(34) corrected and asymmetry figures updated
Eur.Phys.J.C22:655-666,2002
10.1007/s100520100846
null
hep-ph
null
An analysis of Deeply Virtual Compton Scattering (DVCS) is made within the colour dipole model. We compare and contrast two models for the dipole cross-section which have been successful in describing structure function data. Both models agree with the available cross section data on DVCS from HERA. We give predictions for various azimuthal angle asymmetries in HERA kinematics and for the DVCS cross section in the THERA region.
[ { "created": "Fri, 20 Jul 2001 17:32:41 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2001 17:37:36 GMT", "version": "v2" } ]
2011-09-13
[ [ "McDermott", "M.", "" ], [ "Sandapen", "R.", "" ], [ "Shaw", "G.", "" ] ]
An analysis of Deeply Virtual Compton Scattering (DVCS) is made within the colour dipole model. We compare and contrast two models for the dipole cross-section which have been successful in describing structure function data. Both models agree with the available cross section data on DVCS from HERA. We give predictions for various azimuthal angle asymmetries in HERA kinematics and for the DVCS cross section in the THERA region.
hep-ph/9910228
Laura Reina
S. Dawson (BNL) and L. Reina (FSU)
Measuring the Higgs Yukawa Couplings at a Next Linear Collider
6 pages, 6 figures, use sprocl.sty. Proceedings of the LCWS99, International Workshop on Linear Colliders, Sitges, Spain, May 1999
null
null
null
hep-ph
null
We investigate the inclusive production of a Higgs boson with a pair of heavy quarks (t-tbar b-bbar), in e^+e^- collisions at high energies, sqrt(s)=500 GeV and sqrt(s)=1 TeV. We consider both the Standard Model and the supersymmetric case. In both cases O(alpha_s) QCD corrections are included. The associated production of a Higgs boson with a t-tbar pair is extremely sensitive to the top-Higgs Yukawa coupling and may allow the precision measurement of this coupling. In some regions of the supersymmetric parameter space the associated production of a Higgs boson with a b-bbar pair receives large resonant contributions and can have a significant rate.
[ { "created": "Mon, 4 Oct 1999 21:51:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dawson", "S.", "", "BNL" ], [ "Reina", "L.", "", "FSU" ] ]
We investigate the inclusive production of a Higgs boson with a pair of heavy quarks (t-tbar b-bbar), in e^+e^- collisions at high energies, sqrt(s)=500 GeV and sqrt(s)=1 TeV. We consider both the Standard Model and the supersymmetric case. In both cases O(alpha_s) QCD corrections are included. The associated production of a Higgs boson with a t-tbar pair is extremely sensitive to the top-Higgs Yukawa coupling and may allow the precision measurement of this coupling. In some regions of the supersymmetric parameter space the associated production of a Higgs boson with a b-bbar pair receives large resonant contributions and can have a significant rate.
1105.1760
Edmond Iancu
Jorge Casalderrey-Solana and Edmond Iancu
Interference effects in medium-induced gluon radiation
47 pages, 7 figures. Improved physical discussion in Sect. 2. New section added (Sect. 6) on possible implications for in-medium jet evolution. More references added. Conclusions unchanged
null
10.1007/JHEP08(2011)015
CERN-PH-TH-2011-104
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As a step towards understanding the in-medium evolution of a hard jet, we consider the interference pattern for the medium induced gluon radiation produced by a color singlet quark-antiquark antenna embedded in a QCD medium with size L. We focus on the typical kinematics for medium-induced gluon radiation in the BDMPS-Z regime, that is, short formation times \tau_f << L and relatively large emission angles \theta >>\theta_c = 2/\sqrt{\hat q L^3}, with \hat q the `jet quenching' parameter. We demonstrate that, for a dipole opening angle \theta_{q\bar q} larger than \theta_c, the interference between the medium-induced gluon emissions by the quark and the antiquark is parametrically suppressed with respect to the corresponding direct emissions. Physically, this is so since the direct emissions can be delocalized anywhere throughout the medium and thus yield contributions proportional to L. On the contrary, the interference occurs only between gluons emitted at very early times, within the characteristic time scales for quantum and color coherence between the two emitters, which in this regime are much smaller than L. This implies that, for \theta_{q\bar q} >> \theta_c, the medium-induced radiation by the dipole is simply the sum of the two BDMPS-Z spectra individually produced by the quark and the antiquark, without coherence effects like angular ordering. For \theta_{q\bar q} << \theta_c, the BDMPS-Z radiation by the dipole vanishes.
[ { "created": "Mon, 9 May 2011 19:17:36 GMT", "version": "v1" }, { "created": "Tue, 17 May 2011 17:17:43 GMT", "version": "v2" } ]
2015-05-28
[ [ "Casalderrey-Solana", "Jorge", "" ], [ "Iancu", "Edmond", "" ] ]
As a step towards understanding the in-medium evolution of a hard jet, we consider the interference pattern for the medium induced gluon radiation produced by a color singlet quark-antiquark antenna embedded in a QCD medium with size L. We focus on the typical kinematics for medium-induced gluon radiation in the BDMPS-Z regime, that is, short formation times \tau_f << L and relatively large emission angles \theta >>\theta_c = 2/\sqrt{\hat q L^3}, with \hat q the `jet quenching' parameter. We demonstrate that, for a dipole opening angle \theta_{q\bar q} larger than \theta_c, the interference between the medium-induced gluon emissions by the quark and the antiquark is parametrically suppressed with respect to the corresponding direct emissions. Physically, this is so since the direct emissions can be delocalized anywhere throughout the medium and thus yield contributions proportional to L. On the contrary, the interference occurs only between gluons emitted at very early times, within the characteristic time scales for quantum and color coherence between the two emitters, which in this regime are much smaller than L. This implies that, for \theta_{q\bar q} >> \theta_c, the medium-induced radiation by the dipole is simply the sum of the two BDMPS-Z spectra individually produced by the quark and the antiquark, without coherence effects like angular ordering. For \theta_{q\bar q} << \theta_c, the BDMPS-Z radiation by the dipole vanishes.
1909.11470
Emi Masaki
Emi Masaki, Arata Aoki and Jiro Soda
Stability of Axion Dark Matter-Photon Conversion
29 pages, 5 figures, published version
Phys. Rev. D 101, 043505 (2020)
10.1103/PhysRevD.101.043505
KOBE-COSMO-19-17
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is known that a coherently oscillating axion field is a candidate of the dark matter. In the presence of the oscillating axion, the photon can be resonantly produced through the parametric amplification. In the universe, there also exist cosmological magnetic fields which are coherent electromagnetic fields. In the presence of magnetic fields, an axion can be converted into a photon, and vice versa. Thus, it is interesting to investigate what happens for the axion-photon system in the presence of both the axion dark matter and the magnetic fields. This system can be regarded as a coupled system of the axion and the photon whose equations contain the Mathieu type terms. We find that the instability condition is changed in the presence of magnetic fields in contrast to the conventional Mathieu equation. The positions of bifurcation points between stable and unstable are shifted and new instability bands appear. This is because the resonantly amplified axion can be converted to photon, and vice versa.
[ { "created": "Tue, 24 Sep 2019 11:06:00 GMT", "version": "v1" }, { "created": "Tue, 11 Feb 2020 10:22:39 GMT", "version": "v2" } ]
2020-02-12
[ [ "Masaki", "Emi", "" ], [ "Aoki", "Arata", "" ], [ "Soda", "Jiro", "" ] ]
It is known that a coherently oscillating axion field is a candidate of the dark matter. In the presence of the oscillating axion, the photon can be resonantly produced through the parametric amplification. In the universe, there also exist cosmological magnetic fields which are coherent electromagnetic fields. In the presence of magnetic fields, an axion can be converted into a photon, and vice versa. Thus, it is interesting to investigate what happens for the axion-photon system in the presence of both the axion dark matter and the magnetic fields. This system can be regarded as a coupled system of the axion and the photon whose equations contain the Mathieu type terms. We find that the instability condition is changed in the presence of magnetic fields in contrast to the conventional Mathieu equation. The positions of bifurcation points between stable and unstable are shifted and new instability bands appear. This is because the resonantly amplified axion can be converted to photon, and vice versa.
hep-ph/0004074
Eugene Shuster
Krishna Rajagopal and Eugene Shuster
On the Applicability of Weak-Coupling Results in High Density QCD
21 pages, 3 figures, uses LaTeX2e and ReVTeX, updated figures, made minor text changes
Phys.Rev. D62 (2000) 085007
10.1103/PhysRevD.62.085007
MIT-CTP-2969
hep-ph nucl-th
null
Quark matter at asymptotically high baryon chemical potential is in a color superconducting state characterized by a gap Delta. We demonstrate that although present weak-coupling calculations of Delta are formally correct for mu -> Infinity, the contributions which have to this point been neglected are large enough that present results can only be trusted for mu >> mu_c ~ 10^8 MeV. We make this argument by using the gauge dependence of the present calculation as a diagnostic tool. It is known that the present calculation yields a gauge invariant result for mu -> Infinity; we show, however, that the gauge dependence of this result only begins to decrease for mu > mu_c, and conclude that the result can certainly not be trusted for mu < mu_c. In an appendix, we set up the calculation of the influence of the Meissner effect on the magnitude of the gap. This contribution to Delta is, however, much smaller than the neglected contributions whose absence we detect via the resulting gauge dependence.
[ { "created": "Fri, 7 Apr 2000 17:41:30 GMT", "version": "v1" }, { "created": "Thu, 18 May 2000 00:50:55 GMT", "version": "v2" } ]
2009-10-31
[ [ "Rajagopal", "Krishna", "" ], [ "Shuster", "Eugene", "" ] ]
Quark matter at asymptotically high baryon chemical potential is in a color superconducting state characterized by a gap Delta. We demonstrate that although present weak-coupling calculations of Delta are formally correct for mu -> Infinity, the contributions which have to this point been neglected are large enough that present results can only be trusted for mu >> mu_c ~ 10^8 MeV. We make this argument by using the gauge dependence of the present calculation as a diagnostic tool. It is known that the present calculation yields a gauge invariant result for mu -> Infinity; we show, however, that the gauge dependence of this result only begins to decrease for mu > mu_c, and conclude that the result can certainly not be trusted for mu < mu_c. In an appendix, we set up the calculation of the influence of the Meissner effect on the magnitude of the gap. This contribution to Delta is, however, much smaller than the neglected contributions whose absence we detect via the resulting gauge dependence.
hep-ph/0105083
Alexander Friedland
A. Aguirre (IAS, Princeton), C.P. Burgess (IAS, Princeton and McGill University, Montreal, Canada), A. Friedland (IAS, Princeton), D. Nolte (IAS, Princeton)
Astrophysical Constraints on Modifying Gravity at Large Distances
References added, submitted to Classical & Quantum Gravity
Class.Quant.Grav.18:R223-R232,2001
10.1088/0264-9381/18/23/202
null
hep-ph astro-ph gr-qc hep-th
null
Recently, several interesting proposals were made modifying the law of gravity on large scales, within a sensible relativistic formulation. This allows a precise formulation of the idea that such a modification might account for galaxy rotation curves, instead of the usual interpretation of these curves as evidence for dark matter. We here summarize several observational constraints which any such modification must satisfy, and which we believe make more challenging any interpretation of galaxy rotation curves in terms of new gravitational physics.
[ { "created": "Thu, 10 May 2001 22:17:45 GMT", "version": "v1" }, { "created": "Fri, 25 May 2001 21:42:54 GMT", "version": "v2" } ]
2010-04-06
[ [ "Aguirre", "A.", "", "IAS, Princeton" ], [ "Burgess", "C. P.", "", "IAS, Princeton and McGill\n University, Montreal, Canada" ], [ "Friedland", "A.", "", "IAS, Princeton" ], [ "Nolte", "D.", "", "IAS,\n Princeton" ] ]
Recently, several interesting proposals were made modifying the law of gravity on large scales, within a sensible relativistic formulation. This allows a precise formulation of the idea that such a modification might account for galaxy rotation curves, instead of the usual interpretation of these curves as evidence for dark matter. We here summarize several observational constraints which any such modification must satisfy, and which we believe make more challenging any interpretation of galaxy rotation curves in terms of new gravitational physics.
hep-ph/0701212
Zongguo Si
S. Y. Li, Z. G. Si, Z. J. Yang
Doubly Heavy Baryon Production at \gamma \gamma Collider
errors/typos are corrected
Phys.Lett.B648:284-288,2007
10.1016/j.physletb.2007.03.029
SDU-HEP200701
hep-ph
null
The inclusive production of doubly heavy baryons $\Xi_{cc}$ and $\Xi_{bb}$ at $\gamma\gamma$ collider is investigated. It is found that the contribution from the heavy quark pair $QQ$ in color triplet and color sextet are important.
[ { "created": "Thu, 25 Jan 2007 07:21:26 GMT", "version": "v1" }, { "created": "Fri, 26 Jan 2007 10:21:38 GMT", "version": "v2" }, { "created": "Sat, 17 Mar 2007 17:43:01 GMT", "version": "v3" }, { "created": "Wed, 10 Oct 2007 09:50:58 GMT", "version": "v4" } ]
2008-11-26
[ [ "Li", "S. Y.", "" ], [ "Si", "Z. G.", "" ], [ "Yang", "Z. J.", "" ] ]
The inclusive production of doubly heavy baryons $\Xi_{cc}$ and $\Xi_{bb}$ at $\gamma\gamma$ collider is investigated. It is found that the contribution from the heavy quark pair $QQ$ in color triplet and color sextet are important.
hep-ph/0110135
Michal Praszalowicz
M. Praszalowicz, H.-Ch. Kim and K. Goeke
SU(3) Symmetry Breaking and Polarized Parton Densities
10 pages, 6 figures, presented at Dubna Workshop Spin 2001, uses wrapfig.sty
null
null
Jagellonian University preprint TPJU-9/2001
hep-ph
null
We analyze the semileptonic weak decays of the octet baryons in a "model independent" approach, based on the algebraic structure of the Chiral Quark-Soliton Model. We argue that this analysis is in fact more general than the model itself. While the symmetry breaking for the semileptonic decays themselves is not strong, other quantities like $\Delta s$ and $\Delta \Sigma$ are much more affected. We calculate $\Delta \Sigma$ and $\Delta q$ for all octet baryons. Unfortunately, large experimental errors of $\Xi^-$ decays propagate in our analysis, in particular, in the case of $\Delta\Sigma $ and $\Delta s$. Only if the errors for these decays are reduced, the accurate theoretical predictions for $\Delta\Sigma$ and $\Delta s$ will be possible.
[ { "created": "Wed, 10 Oct 2001 12:26:29 GMT", "version": "v1" } ]
2010-06-23
[ [ "Praszalowicz", "M.", "" ], [ "Kim", "H. -Ch.", "" ], [ "Goeke", "K.", "" ] ]
We analyze the semileptonic weak decays of the octet baryons in a "model independent" approach, based on the algebraic structure of the Chiral Quark-Soliton Model. We argue that this analysis is in fact more general than the model itself. While the symmetry breaking for the semileptonic decays themselves is not strong, other quantities like $\Delta s$ and $\Delta \Sigma$ are much more affected. We calculate $\Delta \Sigma$ and $\Delta q$ for all octet baryons. Unfortunately, large experimental errors of $\Xi^-$ decays propagate in our analysis, in particular, in the case of $\Delta\Sigma $ and $\Delta s$. Only if the errors for these decays are reduced, the accurate theoretical predictions for $\Delta\Sigma$ and $\Delta s$ will be possible.
1509.01416
Kai Gallmeister
M. Beitel, K. Gallmeister, C. Greiner
Equilibration of hadrons in HICs via Hagedorn States
To appear in the proceedings of the 15th International Conference on Strangeness in Quark Matter (SQM2015), Dubna, Russian Federation, 6-11 July 2015
null
10.1088/1742-6596/668/1/012057
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hagedorn states (HS) are a tool to model the hadronization process which occurs in the phase transition region between the quark gluon plasma (QGP) and the hadron resonance gas (HRG). These states are believed to appear near the Hagedorn temperature $T_H$ which in our understanding equals the critical temperature $T_c$. A covariantly formulated bootstrap equation is solved to generate the zoo of these particles characterized baryon number $B$, strangeness $S$ and electric charge $Q$. These hadron-like resonances are characterized by being very massive and by not being limited to quantum numbers of known hadrons. All hadronic properties like masses, spectral functions etc.are taken from the hadronic transport model Ultra Relativistic Quantum Molecular Dynamics (UrQMD). Decay chains of single Hagedorn states provide a well description of experimentally observed multiplicity ratios of strange and multi-strange particles. In addition, the final energy spectra of resulting hadrons show a thermal-like distribution with the characteristic Hagedorn temperature $T_H$. Box calculations including these Hagedorn states are performed. Indeed, the time scales leading to equilibration of the system are drastically reduced down to 2...5 fm/c.
[ { "created": "Fri, 4 Sep 2015 11:49:22 GMT", "version": "v1" } ]
2016-02-17
[ [ "Beitel", "M.", "" ], [ "Gallmeister", "K.", "" ], [ "Greiner", "C.", "" ] ]
Hagedorn states (HS) are a tool to model the hadronization process which occurs in the phase transition region between the quark gluon plasma (QGP) and the hadron resonance gas (HRG). These states are believed to appear near the Hagedorn temperature $T_H$ which in our understanding equals the critical temperature $T_c$. A covariantly formulated bootstrap equation is solved to generate the zoo of these particles characterized baryon number $B$, strangeness $S$ and electric charge $Q$. These hadron-like resonances are characterized by being very massive and by not being limited to quantum numbers of known hadrons. All hadronic properties like masses, spectral functions etc.are taken from the hadronic transport model Ultra Relativistic Quantum Molecular Dynamics (UrQMD). Decay chains of single Hagedorn states provide a well description of experimentally observed multiplicity ratios of strange and multi-strange particles. In addition, the final energy spectra of resulting hadrons show a thermal-like distribution with the characteristic Hagedorn temperature $T_H$. Box calculations including these Hagedorn states are performed. Indeed, the time scales leading to equilibration of the system are drastically reduced down to 2...5 fm/c.
hep-ph/9610226
Peter Arnold
Peter Arnold and David Wright
The tricritical point of finite-temperature phase transitions in large N(Higgs) gauge theories
33 pages, LaTex with RevTex, 15 figures in embeded postscript (epsf)
Phys.Rev.D55:6274-6286,1997
10.1103/PhysRevD.55.6274
UW/PT-96-27
hep-ph
null
Gauge theories broken by a single Higgs field are known to have first-order phase transitions in temperature if $\lambda/g^2 \ll 1$, where $g$ is the gauge coupling and $\lambda$ the Higgs self-coupling. If the theory is extended from one to $N$ Higgs doublets, with U($N$) flavor symmetry, the transition is known to be second order for $\lambda/g^2 \gtrsim 1$ in the $N\to\infty$ limit. We show that one can in principal compute the tricritical value of $\lambda/g^2$, separating first from second-order transitions, to any order in $1/N$. In particular, scalar fluctuations at the transition damp away the usual problems with the infrared behavior of high-temperature non-Abelian gauge theories. We explicitly compute the tricritical value of $\lambda/g^2$ for U(1) and SU(2) gauge theory to next-to-leading order in $1/N$.
[ { "created": "Wed, 2 Oct 1996 22:38:53 GMT", "version": "v1" } ]
2010-02-16
[ [ "Arnold", "Peter", "" ], [ "Wright", "David", "" ] ]
Gauge theories broken by a single Higgs field are known to have first-order phase transitions in temperature if $\lambda/g^2 \ll 1$, where $g$ is the gauge coupling and $\lambda$ the Higgs self-coupling. If the theory is extended from one to $N$ Higgs doublets, with U($N$) flavor symmetry, the transition is known to be second order for $\lambda/g^2 \gtrsim 1$ in the $N\to\infty$ limit. We show that one can in principal compute the tricritical value of $\lambda/g^2$, separating first from second-order transitions, to any order in $1/N$. In particular, scalar fluctuations at the transition damp away the usual problems with the infrared behavior of high-temperature non-Abelian gauge theories. We explicitly compute the tricritical value of $\lambda/g^2$ for U(1) and SU(2) gauge theory to next-to-leading order in $1/N$.
hep-ph/9403348
Larbi Beldjoudi
L.Beldjoudi and T.N Truong (CPT Ecole Polytechnique)
$\pi \pi$ Scattering and Pion Form Factors
8 pages, Tex, 4 postscript figures appended at the end. CPTH-A292.0294
null
null
null
hep-ph
null
The S and P wave $\pi \pi$ phase shifts are recalculated in terms of two phenomenological parameters using the one loop CPTh and the elastic unitarity condition. Using these phase shifts, the vector and scalar form factors are calculated and shown to be in a good agreement with experimental data. It is found that the simpler and more phenomenological approach, where the left hand cut contributions to the partial wave amplitude are neglected, yields approximately the same result.
[ { "created": "Wed, 23 Mar 1994 21:43:21 GMT", "version": "v1" } ]
2016-09-01
[ [ "Beldjoudi", "L.", "", "CPT Ecole Polytechnique" ], [ "Truong", "T. N", "", "CPT Ecole Polytechnique" ] ]
The S and P wave $\pi \pi$ phase shifts are recalculated in terms of two phenomenological parameters using the one loop CPTh and the elastic unitarity condition. Using these phase shifts, the vector and scalar form factors are calculated and shown to be in a good agreement with experimental data. It is found that the simpler and more phenomenological approach, where the left hand cut contributions to the partial wave amplitude are neglected, yields approximately the same result.
0709.3272
Feng Yuan
Feng Yuan
Azimuthal Asymmetric Distribution of Hadrons Inside a Jet at Hadron Collider
10 pages, 4 figures
Phys.Rev.Lett.100:032003,2008
10.1103/PhysRevLett.100.032003
RBRC-689
hep-ph
null
We study the azimuthal asymmetric distribution of hadrons inside a high energy jet in the single transverse polarized proton proton scattering, coming from the Collins effect multiplied by the quark transversity distribution. We argue that the Collins function in this process is the same as that in the semi-inclusive deep inelastic scattering. The experimental study of this process will provide us important information on the quark transversity distribution and test the universality of the fragmentation functions.
[ { "created": "Thu, 20 Sep 2007 18:08:44 GMT", "version": "v1" } ]
2008-11-26
[ [ "Yuan", "Feng", "" ] ]
We study the azimuthal asymmetric distribution of hadrons inside a high energy jet in the single transverse polarized proton proton scattering, coming from the Collins effect multiplied by the quark transversity distribution. We argue that the Collins function in this process is the same as that in the semi-inclusive deep inelastic scattering. The experimental study of this process will provide us important information on the quark transversity distribution and test the universality of the fragmentation functions.
hep-ph/0702278
Bumseok Kyae
Jihn E. Kim, Ji-Hun Kim, Bumseok Kyae
Superstring standard model from Z_{12-I} orbifold compactification with and without exotics, and effective R-parity
1+36 pages, JHEP3 class
JHEP 0706:034,2007
10.1088/1126-6708/2007/06/034
SNUTP 07-003, KIAS-P07009
hep-ph hep-th
null
We construct a supersymmetric standard model in the context of the $Z_{12-I}$ orbifold compactification of the heterotic string theory. The gauge group is $SU(3)_c\times SU(2)_L\times U(1)_Y\times U(1)^4\times[SO(10)\times U(1)^3]'$. We obtain three chiral families, $3\times\{Q,d^c,u^c,L,e^c,\nu^c\}$, and Higgs doublets. There are numerous neutral singlets many of which can have VEVs so that low energy phenomenology on Yukawa couplings can be satisfied. In one assignment (Model E) of the electroweak hypercharge, we obtain the string scale value of $sin^2\theta_W^0={3/8}$ and another exactly massless {\it exphoton} (in addition to the photon) coupling to exotic particles only. There are color triplet and anti-triplet exotics, $\alpha$ and $\bar{\alpha}$, $SU(2)_L$ doublet exotics, $\delta$ and $\bar{\delta}$, and $SU(3)_c\times SU(2)_L$ singlet but $Y={2/3},-{1/3},-{2/3},{1/3}$ exotics, $\xi,\eta,\bar{\xi}, \bar{\eta}$. We show that all these vector-like exotics achieve heavy masses by appropriate VEVs of neutral singlets. One can find an effective R-parity between light (electroweak scale) particles so that proton and the LSP can live sufficiently long. In another assignment (Model S) of the electroweak hypercharge, there does not appear any exotic particle but $sin^2\theta_W^0={3/14}$.
[ { "created": "Tue, 27 Feb 2007 16:41:59 GMT", "version": "v1" } ]
2010-10-27
[ [ "Kim", "Jihn E.", "" ], [ "Kim", "Ji-Hun", "" ], [ "Kyae", "Bumseok", "" ] ]
We construct a supersymmetric standard model in the context of the $Z_{12-I}$ orbifold compactification of the heterotic string theory. The gauge group is $SU(3)_c\times SU(2)_L\times U(1)_Y\times U(1)^4\times[SO(10)\times U(1)^3]'$. We obtain three chiral families, $3\times\{Q,d^c,u^c,L,e^c,\nu^c\}$, and Higgs doublets. There are numerous neutral singlets many of which can have VEVs so that low energy phenomenology on Yukawa couplings can be satisfied. In one assignment (Model E) of the electroweak hypercharge, we obtain the string scale value of $sin^2\theta_W^0={3/8}$ and another exactly massless {\it exphoton} (in addition to the photon) coupling to exotic particles only. There are color triplet and anti-triplet exotics, $\alpha$ and $\bar{\alpha}$, $SU(2)_L$ doublet exotics, $\delta$ and $\bar{\delta}$, and $SU(3)_c\times SU(2)_L$ singlet but $Y={2/3},-{1/3},-{2/3},{1/3}$ exotics, $\xi,\eta,\bar{\xi}, \bar{\eta}$. We show that all these vector-like exotics achieve heavy masses by appropriate VEVs of neutral singlets. One can find an effective R-parity between light (electroweak scale) particles so that proton and the LSP can live sufficiently long. In another assignment (Model S) of the electroweak hypercharge, there does not appear any exotic particle but $sin^2\theta_W^0={3/14}$.
2112.05058
Rainer Dick
Siddharth Tiwary and Rainer Dick
Constraints on antisymmetric tensor fields from Bhabha scattering
5 pages
Eur. Phys. J. C 81 (2021) 1115
10.1140/epjc/s10052-021-09915-x
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Antisymmetric tensor fields are a compelling prediction of string theory. This makes them an interesting target for particle physics because antisymmetric tensors may couple to electromagnetic dipole moments, thus opening a possible discovery opportunity for string theory. The strongest constraints on electromagnetic dipole couplings would arise from couplings to electrons, where these couplings would contribute to Moller and Bhabha scattering. Previous measurements of Bhabha scattering constrain the couplings to $\tilde{M}_e m_C>7.1\times 10^4\,\mathrm{GeV}^2$, where $m_C$ is the mass of the antisymmetric tensor field and $\tilde{M}_e$ is an effective mass scale appearing in the electromagnetic dipole coupling.
[ { "created": "Thu, 9 Dec 2021 17:35:02 GMT", "version": "v1" }, { "created": "Sat, 18 Dec 2021 16:34:49 GMT", "version": "v2" } ]
2021-12-21
[ [ "Tiwary", "Siddharth", "" ], [ "Dick", "Rainer", "" ] ]
Antisymmetric tensor fields are a compelling prediction of string theory. This makes them an interesting target for particle physics because antisymmetric tensors may couple to electromagnetic dipole moments, thus opening a possible discovery opportunity for string theory. The strongest constraints on electromagnetic dipole couplings would arise from couplings to electrons, where these couplings would contribute to Moller and Bhabha scattering. Previous measurements of Bhabha scattering constrain the couplings to $\tilde{M}_e m_C>7.1\times 10^4\,\mathrm{GeV}^2$, where $m_C$ is the mass of the antisymmetric tensor field and $\tilde{M}_e$ is an effective mass scale appearing in the electromagnetic dipole coupling.
0906.2019
Edward Shuryak
Marco Cristoforetti and Edward Shuryak
Bose-Einstein Condensation of strongly interacting bosons: from liquid ${}^4$He to QCD monopoles
null
Phys.Rev.D80:054013,2009
10.1103/PhysRevD.80.054013
null
hep-ph cond-mat.stat-mech
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Starting from classic work of Feynman on the $\lambda$-point of liquid Helium, we show that his idea of universal action per particle at the BEC transition point is much more robust that it was known before. Using a simple "moving string model" for supercurrent and calculating the action, both semiclassically and numerically, we show that the critical action is the same for noninteracting and strongly interacting systems such as liquid ${}^4$He. Inversely, one can obtain accurate dependence of critical temperature on density: one important consequence is that high density (solid) He cannot be a BEC state of He atoms, with upper density accurately matching the observations. We then use this model for the deconfinement phase transition of QCD-like gauge theories, treated as BEC of (color)magnetic monopoles. We start with Feynman-like approach without interaction, estimating the monopole mass at $T_c$. Then we include monopole's Coulomb repulsion, and formulate a relation between the mass, density and coupling which should be fulfilled at the deconfinement point. We end up proposing various ways to test on the lattice whether it is indeed the BEC point for monopoles.
[ { "created": "Wed, 10 Jun 2009 21:20:08 GMT", "version": "v1" } ]
2009-11-06
[ [ "Cristoforetti", "Marco", "" ], [ "Shuryak", "Edward", "" ] ]
Starting from classic work of Feynman on the $\lambda$-point of liquid Helium, we show that his idea of universal action per particle at the BEC transition point is much more robust that it was known before. Using a simple "moving string model" for supercurrent and calculating the action, both semiclassically and numerically, we show that the critical action is the same for noninteracting and strongly interacting systems such as liquid ${}^4$He. Inversely, one can obtain accurate dependence of critical temperature on density: one important consequence is that high density (solid) He cannot be a BEC state of He atoms, with upper density accurately matching the observations. We then use this model for the deconfinement phase transition of QCD-like gauge theories, treated as BEC of (color)magnetic monopoles. We start with Feynman-like approach without interaction, estimating the monopole mass at $T_c$. Then we include monopole's Coulomb repulsion, and formulate a relation between the mass, density and coupling which should be fulfilled at the deconfinement point. We end up proposing various ways to test on the lattice whether it is indeed the BEC point for monopoles.
1405.4633
Sara Taheri Monfared
Sara Taheri Monfared, Zahra Haddadi, Ali N. Khorramian
Target mass corrections and higher twist effects in polarized deep-inelastic scattering
14 pages, 13 figures, 8 tables
Physical Review D 89, 074052 (2014)
10.1103/PhysRevD.89.074052
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a next-to-leading-order QCD analysis to world data on polarized structure functions $g_1$ and $g_2$ in a fixed-flavor number scheme. We include target mass corrections and higher twist effects in our fitting procedure and study their non-negligible effects on physically interesting quantities. Twist-3 contributions to both polarized structure functions are determined, and the accuracy of the extracted polarized parton distribution functions is improved. $^{3}\rm He$ and $^{3}\rm H$ polarized structure functions are described based on our fit result. Moreover, sum rules are derived and compared with available theoretical and experimental results.
[ { "created": "Mon, 19 May 2014 08:15:16 GMT", "version": "v1" } ]
2014-05-22
[ [ "Monfared", "Sara Taheri", "" ], [ "Haddadi", "Zahra", "" ], [ "Khorramian", "Ali N.", "" ] ]
We perform a next-to-leading-order QCD analysis to world data on polarized structure functions $g_1$ and $g_2$ in a fixed-flavor number scheme. We include target mass corrections and higher twist effects in our fitting procedure and study their non-negligible effects on physically interesting quantities. Twist-3 contributions to both polarized structure functions are determined, and the accuracy of the extracted polarized parton distribution functions is improved. $^{3}\rm He$ and $^{3}\rm H$ polarized structure functions are described based on our fit result. Moreover, sum rules are derived and compared with available theoretical and experimental results.
1005.0628
Linda Carpenter
Linda M. Carpenter and Arvind Rajaraman
Revisiting Constraints on Fourth Generation Neutrino Masses
7 pages 1 fig
Phys.Rev.D82:114019,2010
10.1103/PhysRevD.82.114019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the current experimental bounds on fourth-generation Majorana neutrino masses, including the effects of right handed neutrinos. Current bounds from LEPII are significantly altered by a global analysis. We show that the current bounds on fourth generation neutrinos decaying to eW and mu W can be reduced to about 80 GeV (from the current bound of 90 GeV), while a neutrino decaying to tau W can be as light as 62.1 GeV. The weakened bound opens up a neutrino decay channel for intermediate mass Higgs, and interesting multi-particle final states for Higgs and fourth generation lepton decays.
[ { "created": "Tue, 4 May 2010 20:10:10 GMT", "version": "v1" } ]
2011-01-17
[ [ "Carpenter", "Linda M.", "" ], [ "Rajaraman", "Arvind", "" ] ]
We revisit the current experimental bounds on fourth-generation Majorana neutrino masses, including the effects of right handed neutrinos. Current bounds from LEPII are significantly altered by a global analysis. We show that the current bounds on fourth generation neutrinos decaying to eW and mu W can be reduced to about 80 GeV (from the current bound of 90 GeV), while a neutrino decaying to tau W can be as light as 62.1 GeV. The weakened bound opens up a neutrino decay channel for intermediate mass Higgs, and interesting multi-particle final states for Higgs and fourth generation lepton decays.
hep-ph/9509267
null
V.M. Belyaev and A.V. Radyushkin
Soft Contribution to Form Factors of $\gamma^* p \to \Delta^+$ Transition
29 pages, REVTeX, 5 eps-figures in uuencoded gz-compressed .tar file
Phys.Rev.D53:6509-6521,1996
10.1103/PhysRevD.53.6509
CEBAF-TH-95-15
hep-ph
null
The purely nonperturbative soft contribution to the $\gamma^* p \to \Delta^+$ transition form factors is estimated using the local quark-hadron duality approach. Our results show that the soft contribution is dominated by the magnetic transition: the ratio $G_E^*(Q^2)/G_M^*(Q^2)$ is small for all accessible $Q^2$, in contrast to pQCD expectations that $G_E^*(Q^2) \to -G_M^*(Q^2)$. We also found that the soft contribution to the magnetic form factor is large enough to explain the magnitude of existing experimental data.
[ { "created": "Mon, 11 Sep 1995 23:54:42 GMT", "version": "v1" }, { "created": "Tue, 12 Sep 1995 13:32:33 GMT", "version": "v2" }, { "created": "Fri, 15 Sep 1995 21:54:05 GMT", "version": "v3" } ]
2014-11-17
[ [ "Belyaev", "V. M.", "" ], [ "Radyushkin", "A. V.", "" ] ]
The purely nonperturbative soft contribution to the $\gamma^* p \to \Delta^+$ transition form factors is estimated using the local quark-hadron duality approach. Our results show that the soft contribution is dominated by the magnetic transition: the ratio $G_E^*(Q^2)/G_M^*(Q^2)$ is small for all accessible $Q^2$, in contrast to pQCD expectations that $G_E^*(Q^2) \to -G_M^*(Q^2)$. We also found that the soft contribution to the magnetic form factor is large enough to explain the magnitude of existing experimental data.
hep-ph/9910230
Gerald B. Cleaver
G.B. Cleaver, A.E. Faraggi, D.V. Nanopoulos, and J.W. Walker
A Minimal Superstring Standard Model II: A Phenomenological Study
41 pages. Standard Latex
Nucl.Phys. B593 (2001) 471-504
10.1016/S0550-3213(00)00543-5
ACT-9/99, CTP-TAMU-37/99, TPI-MINN-99/46, UMN-TH-1821-99
hep-ph hep-th
null
Recently, we demonstrated the existence of heterotic--string solutions in which the observable sector effective field theory just below the string scale reduces to that of the MSSM, with the standard observable gauge group being just SU(3)_C x SU(2)_L x U(1)_Y and the SU(3)_C x SU(2)_L x U(1)_Y-charged spectrum of the observable sector consisting solely of the MSSM spectrum. Associated with this model is a set of distinct flat directions of vacuum expectation values (VEVs) of non-Abelian singlet fields that all produce solely the MSSM spectrum. In this paper, we study the effective superpotential induced by these choices of flat directions. We investigate whether sufficient degrees of freedom exist in these singlet flat directions to satisfy various phenomenological constraints imposed by the observed Standard Model data. For each flat direction, the effective superpotential is given to sixth order. The variations in the singlet and hidden sector low energy spectrums are analyzed. We then determine the mass matrices (to all finite orders) for the three generations of MSSM quarks and leptons. Possible Higgs mu-terms are investigated. We conclude by considering generalizations of our flat directions involving VEVs of non-Abelian fields.
[ { "created": "Mon, 4 Oct 1999 22:50:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Cleaver", "G. B.", "" ], [ "Faraggi", "A. E.", "" ], [ "Nanopoulos", "D. V.", "" ], [ "Walker", "J. W.", "" ] ]
Recently, we demonstrated the existence of heterotic--string solutions in which the observable sector effective field theory just below the string scale reduces to that of the MSSM, with the standard observable gauge group being just SU(3)_C x SU(2)_L x U(1)_Y and the SU(3)_C x SU(2)_L x U(1)_Y-charged spectrum of the observable sector consisting solely of the MSSM spectrum. Associated with this model is a set of distinct flat directions of vacuum expectation values (VEVs) of non-Abelian singlet fields that all produce solely the MSSM spectrum. In this paper, we study the effective superpotential induced by these choices of flat directions. We investigate whether sufficient degrees of freedom exist in these singlet flat directions to satisfy various phenomenological constraints imposed by the observed Standard Model data. For each flat direction, the effective superpotential is given to sixth order. The variations in the singlet and hidden sector low energy spectrums are analyzed. We then determine the mass matrices (to all finite orders) for the three generations of MSSM quarks and leptons. Possible Higgs mu-terms are investigated. We conclude by considering generalizations of our flat directions involving VEVs of non-Abelian fields.
1905.00703
Wayne de Paula
Tobias Frederico, Dyana C. Duarte, Wayne de Paula, Emanuel Ydrefors, Shaoyang Jia and Pieter Maris
Towards Minkowski space solutions of Dyson-Schwinger Equations through un-Wick rotation
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The fermion self-energy is calculated from the rainbow-ladder truncation of the Dyson-Schwinger equation (DSE) in quantum electrodynamics (QED) for spacelike momenta and in the complex momentum plane close to the timelike region, both using Pauli-Villars regularization. Specifically, the DSE is solved in the complex momentum plane by rotating either the energy component of the four-momentum or the magnitude of Euclidean four-momentum to reach the timelike region in Minkowski space. The coupling constant is appropriately chosen to ensure the singularities of the fermion propagator are located in the timelike region while producing significant differences from the perturbative solutions. For simplicity, we choose Feynman gauge, but the method is applicable in other covariant gauges as well. We demonstrate that the approximate spectral representation based on the fermion self-energy near the timelike region is consistent with the solution of the DSE directly in the Euclidean space.
[ { "created": "Wed, 1 May 2019 15:13:50 GMT", "version": "v1" }, { "created": "Fri, 3 May 2019 00:55:53 GMT", "version": "v2" } ]
2019-05-21
[ [ "Frederico", "Tobias", "" ], [ "Duarte", "Dyana C.", "" ], [ "de Paula", "Wayne", "" ], [ "Ydrefors", "Emanuel", "" ], [ "Jia", "Shaoyang", "" ], [ "Maris", "Pieter", "" ] ]
The fermion self-energy is calculated from the rainbow-ladder truncation of the Dyson-Schwinger equation (DSE) in quantum electrodynamics (QED) for spacelike momenta and in the complex momentum plane close to the timelike region, both using Pauli-Villars regularization. Specifically, the DSE is solved in the complex momentum plane by rotating either the energy component of the four-momentum or the magnitude of Euclidean four-momentum to reach the timelike region in Minkowski space. The coupling constant is appropriately chosen to ensure the singularities of the fermion propagator are located in the timelike region while producing significant differences from the perturbative solutions. For simplicity, we choose Feynman gauge, but the method is applicable in other covariant gauges as well. We demonstrate that the approximate spectral representation based on the fermion self-energy near the timelike region is consistent with the solution of the DSE directly in the Euclidean space.
1502.01440
Osamu Yasuda
Osamu Yasuda
Constraints on non-standard flavor-dependent interactions from Superkamiokande and Hyperkamiokande
6 pages, 2 figures. Contribution to 16th International Workshop on Neutrino Factories and Future Neutrino Beam Facilities, 25-30 August, 2014. University of Glasgow, UK. A minor change added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the constraint on the flavor-dependent neutral current Non-Standard Interactions in propagation from atmospheric neutrino experiments Superkamiokande and Hyperkamiokande. With the ansatz where the parameters which have strong constraints from other experiments are neglected, we show how these experiments put constraints on the remaining parameters of the Non-Standard Interactions.
[ { "created": "Thu, 5 Feb 2015 06:50:50 GMT", "version": "v1" }, { "created": "Fri, 6 Feb 2015 01:28:49 GMT", "version": "v2" } ]
2015-02-09
[ [ "Yasuda", "Osamu", "" ] ]
We investigate the constraint on the flavor-dependent neutral current Non-Standard Interactions in propagation from atmospheric neutrino experiments Superkamiokande and Hyperkamiokande. With the ansatz where the parameters which have strong constraints from other experiments are neglected, we show how these experiments put constraints on the remaining parameters of the Non-Standard Interactions.
1705.09292
Jan Heisig
Mathias Garny, Jan Heisig, Benedikt L\"ulf, Stefan Vogl
Coannihilation without chemical equilibrium
12 pages + references, 10 figures; v2: Discussion of kinetic equilibrium extended, matches published version
Phys. Rev. D 96, 103521 (2017)
10.1103/PhysRevD.96.103521
TUM-HEP 1085/17, TTK-17-18
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Chemical equilibrium is a commonly made assumption in the freeze-out calculation of coannihilating dark matter. We explore the possible failure of this assumption and find a new conversion-driven freeze-out mechanism. Considering a representative simplified model inspired by supersymmetry with a neutralino- and sbottom-like particle we find regions in parameter space with very small couplings accommodating the measured relic density. In this region freeze-out takes place out of chemical equilibrium and dark matter self-annihilation is thoroughly inefficient. The relic density is governed primarily by the size of the conversion terms in the Boltzmann equations. Due to the small dark matter coupling the parameter region is immune to direct detection but predicts an interesting signature of disappearing tracks or displaced vertices at the LHC. Unlike freeze-in or superWIMP scenarios, conversion-driven freeze-out is not sensitive to the initial conditions at the end of reheating.
[ { "created": "Thu, 25 May 2017 18:00:01 GMT", "version": "v1" }, { "created": "Fri, 17 Nov 2017 13:49:14 GMT", "version": "v2" } ]
2017-11-20
[ [ "Garny", "Mathias", "" ], [ "Heisig", "Jan", "" ], [ "Lülf", "Benedikt", "" ], [ "Vogl", "Stefan", "" ] ]
Chemical equilibrium is a commonly made assumption in the freeze-out calculation of coannihilating dark matter. We explore the possible failure of this assumption and find a new conversion-driven freeze-out mechanism. Considering a representative simplified model inspired by supersymmetry with a neutralino- and sbottom-like particle we find regions in parameter space with very small couplings accommodating the measured relic density. In this region freeze-out takes place out of chemical equilibrium and dark matter self-annihilation is thoroughly inefficient. The relic density is governed primarily by the size of the conversion terms in the Boltzmann equations. Due to the small dark matter coupling the parameter region is immune to direct detection but predicts an interesting signature of disappearing tracks or displaced vertices at the LHC. Unlike freeze-in or superWIMP scenarios, conversion-driven freeze-out is not sensitive to the initial conditions at the end of reheating.
2307.09516
Martin Bauer
Martin Bauer and Guillaume Rostagni
Fifth forces from QCD axions scale differently
7 pages, 2 figures
null
null
IPPP/23/35
hep-ph
http://creativecommons.org/licenses/by/4.0/
We reexamine the low-energy potential for a macroscopic fifth force generated from the exchange of two axions. The shift-symmetry of the linear axion interactions leads to a potential falling off as $V(r) \sim 1/r^5$. We find that in the case of the QCD axion higher-order terms in the Lagrangian break the shift symmetry and lead to the dominant contribution to the potential scaling as $V(r) \sim 1/r^3$. These terms are generated by the same physics responsible for the axion mass and therefore the new contributions to the potential induce a different force for external nucleons and leptons. We demonstrate how this result affects the sensitivity of searches for new long-range forces.
[ { "created": "Tue, 18 Jul 2023 18:00:33 GMT", "version": "v1" } ]
2023-07-20
[ [ "Bauer", "Martin", "" ], [ "Rostagni", "Guillaume", "" ] ]
We reexamine the low-energy potential for a macroscopic fifth force generated from the exchange of two axions. The shift-symmetry of the linear axion interactions leads to a potential falling off as $V(r) \sim 1/r^5$. We find that in the case of the QCD axion higher-order terms in the Lagrangian break the shift symmetry and lead to the dominant contribution to the potential scaling as $V(r) \sim 1/r^3$. These terms are generated by the same physics responsible for the axion mass and therefore the new contributions to the potential induce a different force for external nucleons and leptons. We demonstrate how this result affects the sensitivity of searches for new long-range forces.
hep-ph/0701077
Boris Ioffe L
B.L.Ioffe and A.G.Oganesian
Axial anomaly and the precise value of the $\pi^0 \to 2 \gamma$ decay width
8 pages, few misprints are corrected
Phys.Lett.B647:389-393,2007
10.1016/j.physletb.2007.02.021
null
hep-ph
null
The anomaly in the vacuum expectation value of the product of axial and two vector currents (AVV) in QCD is investigated. The goal is to determine from its value the $\pi^0 \to 2 \gamma$ decay width with high precision. The sum rule for AVV formfactor is studied. The difference $f_{\pi^0} - f_{\pi^+}$ caused by strong interaction is calculated and appears to be small. The $\pi^0 - \eta$ mixing is accounted. The $\pi^0 \to 2 \gamma$ decay width determined theoretically from the axial anomaly is found to be $\Gamma(\pi^0 \to 2 \gamma) = 7.93 eV$ with an error $\sim 1.5%$. The measurement of the $\pi^0 \to 2 \gamma$ decay width at the same level of accuracy would allow one to achieve a high precision test of QCD.
[ { "created": "Wed, 10 Jan 2007 13:58:49 GMT", "version": "v1" }, { "created": "Mon, 5 Mar 2007 14:48:32 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ioffe", "B. L.", "" ], [ "Oganesian", "A. G.", "" ] ]
The anomaly in the vacuum expectation value of the product of axial and two vector currents (AVV) in QCD is investigated. The goal is to determine from its value the $\pi^0 \to 2 \gamma$ decay width with high precision. The sum rule for AVV formfactor is studied. The difference $f_{\pi^0} - f_{\pi^+}$ caused by strong interaction is calculated and appears to be small. The $\pi^0 - \eta$ mixing is accounted. The $\pi^0 \to 2 \gamma$ decay width determined theoretically from the axial anomaly is found to be $\Gamma(\pi^0 \to 2 \gamma) = 7.93 eV$ with an error $\sim 1.5%$. The measurement of the $\pi^0 \to 2 \gamma$ decay width at the same level of accuracy would allow one to achieve a high precision test of QCD.
hep-ph/0110337
Krzysztof Redlich
K. Redlich (GSI, Darmstadt & U. of Wroclaw), J. Cleymans (U. of Cape Town), H. Oeschler (U. of Darmstadt), A. Tounsi (U. of Paris 7)
Conservation Laws and Particle Production in Heavy Ion Collisions
Invited talk at International Symposium on Hadron and Nuclei, Seoul, Korea, 20-22 Feb 2001
null
10.1063/1.1425518
GSI-Preprint-2001-12
hep-ph
null
We discuss the role of the conservation laws related with U(1) internal symmetry group in the statistical model description of particle productions in ultrarelativistic heavy ion collisions. We derive and show the differences in particle multiplicities in the canonical and the grand canonical formulation of quantum number conservation. The time evolution and the approach to chemical equilibrium in the above ensembles is discussed in terms of kinetic master equation. The application of the statistical model to the description of (multi)strange particle yields at GSI/SIS and the SPS energies is also presented.
[ { "created": "Thu, 25 Oct 2001 18:42:23 GMT", "version": "v1" }, { "created": "Fri, 16 Nov 2001 14:00:13 GMT", "version": "v2" } ]
2009-11-07
[ [ "Redlich", "K.", "", "GSI, Darmstadt & U. of Wroclaw" ], [ "Cleymans", "J.", "", "U. of Cape\n Town" ], [ "Oeschler", "H.", "", "U. of Darmstadt" ], [ "Tounsi", "A.", "", "U. of Paris 7" ] ]
We discuss the role of the conservation laws related with U(1) internal symmetry group in the statistical model description of particle productions in ultrarelativistic heavy ion collisions. We derive and show the differences in particle multiplicities in the canonical and the grand canonical formulation of quantum number conservation. The time evolution and the approach to chemical equilibrium in the above ensembles is discussed in terms of kinetic master equation. The application of the statistical model to the description of (multi)strange particle yields at GSI/SIS and the SPS energies is also presented.
0802.3592
Thomas Kernreiter
A. Bartl, K. Hohenwarter-Sodek, T. Kernreiter, O. Kittel, M. Terwort
CP observables with spin-spin correlations in chargino production
21pp; discussion of background processes improved, references added; final version for Nucl. Phys. B
Nucl.Phys.B802:77-91,2008
10.1016/j.nuclphysb.2008.04.031
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the CP-violating terms of the spin-spin correlations in chargino production e+e- -> chi^+/-_1 chi^-/+_2, and their subsequent two-body decays into sneutrinos plus leptons. We propose novel CP-sensitive observables with the help of T-odd products of the spin-spin terms. These terms depend on the polarizations of both charginos, with one polarization perpendicular to the production plane. We identify two classes of CP-sensitive observables; one requires the reconstruction of the production plane, the other not. Our framework is the Minimal Supersymmetric Standard Model with complex parameters.
[ { "created": "Mon, 25 Feb 2008 11:05:08 GMT", "version": "v1" }, { "created": "Fri, 16 May 2008 18:16:04 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bartl", "A.", "" ], [ "Hohenwarter-Sodek", "K.", "" ], [ "Kernreiter", "T.", "" ], [ "Kittel", "O.", "" ], [ "Terwort", "M.", "" ] ]
We study the CP-violating terms of the spin-spin correlations in chargino production e+e- -> chi^+/-_1 chi^-/+_2, and their subsequent two-body decays into sneutrinos plus leptons. We propose novel CP-sensitive observables with the help of T-odd products of the spin-spin terms. These terms depend on the polarizations of both charginos, with one polarization perpendicular to the production plane. We identify two classes of CP-sensitive observables; one requires the reconstruction of the production plane, the other not. Our framework is the Minimal Supersymmetric Standard Model with complex parameters.
2111.09909
Ruben Sandapen
Ruben Sandapen
Two Schr\"odinger-like Equations for hadrons
8 pages, 4 figures. Talk given at the Virtual Tribute to Quark Confinement and the Hadron Spectrum, organized by the University of Stavanger, Norway. August 2nd - 6th, 2021
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, based on [1,2], I argue that the holographic Schr\"odinger Equation of $(3+1)$-dim, conformal light-front QCD and the 't Hooft Equation of $(1+1)$-dim, large $N_c$ QCD, can be complementary to each other in providing a first approximation to hadron spectroscopy. Together, the two equations play a role in hadronic physics analogous that of the ordinary Schr\"odinger Equation in atomic physics.
[ { "created": "Thu, 18 Nov 2021 19:12:12 GMT", "version": "v1" } ]
2021-11-22
[ [ "Sandapen", "Ruben", "" ] ]
In this talk, based on [1,2], I argue that the holographic Schr\"odinger Equation of $(3+1)$-dim, conformal light-front QCD and the 't Hooft Equation of $(1+1)$-dim, large $N_c$ QCD, can be complementary to each other in providing a first approximation to hadron spectroscopy. Together, the two equations play a role in hadronic physics analogous that of the ordinary Schr\"odinger Equation in atomic physics.
1306.4138
Y.H Ahn
Y. H. Ahn and Seungwon Baek
A dynamical CP source for CKM, PMNS and Leptogenesis
40 pages, 11 figures; version published in Phys. Rev. D. arXiv admin note: substantial text overlap with arXiv:1207.1229, arXiv:1304.0921, arXiv:1303.4863
null
10.1103/PhysRevD.88.036017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a simple model for the spontaneous CP violation based on $SU(2)_{L}\times U(1)_{Y}\times A_{4}\times CP\times Z_{2}$ symmetry for quarks and leptons in a seesaw framework. In our model CP is spontaneously broken at high energies, after breaking of flavor symmetry, by a complex vacuum expectation value of $A_{4}$-triplet and gauge singlet scalar field. And, certain effective dimension-5 operators are introduced in the quark Lagrangian as an equal footing, which lead the quark mixing matrix to the Cabibbo-Kobayashi-Maskawa (CKM) one in the form, while the lepton Lagrangian is renormalizable, which gives rise to a non-degenerate Dirac neutrino Yukawa matrix and an unique CP-phase, and which in turn explains the non-zero value of $\theta_{13}\simeq9^{\circ}$ and two large mixing angles $\theta_{12}, \theta_{23}$. We show that the spontaneously generated CP phase "$\xi$" could become a natural source of leptogenesis as well as CP violations in the CKM and Pontecorvo-Maki-Nakagawa-Sakata (PMNS). Moreover, we provide a solution for the strong CP problem. Interestingly enough, we show that, for around $\xi\simeq120^{\circ}$, the quarks lead to the correct CKM CP-phase corresponding to $\delta^{q}_{CP}\simeq67^{\circ}$, while the leptons with the measured value of $\theta_{13}$ favor $\delta_{CP}=$, $|\theta_{23}-45^{\circ}|\rightarrow0$ for normal mass hierarchy and $\delta_{CP}=$, $|\theta_{23}-45^{\circ}|\rightarrow5^{\circ}$ for inverted one. As a numerical study in the lepton sector, we show low-energy phenomenologies and leptogenesis for the normal and inverted case, respectively, and a link between them.
[ { "created": "Tue, 18 Jun 2013 11:01:58 GMT", "version": "v1" }, { "created": "Wed, 10 Jul 2013 00:40:16 GMT", "version": "v2" }, { "created": "Thu, 22 Aug 2013 06:13:19 GMT", "version": "v3" } ]
2013-09-03
[ [ "Ahn", "Y. H.", "" ], [ "Baek", "Seungwon", "" ] ]
We propose a simple model for the spontaneous CP violation based on $SU(2)_{L}\times U(1)_{Y}\times A_{4}\times CP\times Z_{2}$ symmetry for quarks and leptons in a seesaw framework. In our model CP is spontaneously broken at high energies, after breaking of flavor symmetry, by a complex vacuum expectation value of $A_{4}$-triplet and gauge singlet scalar field. And, certain effective dimension-5 operators are introduced in the quark Lagrangian as an equal footing, which lead the quark mixing matrix to the Cabibbo-Kobayashi-Maskawa (CKM) one in the form, while the lepton Lagrangian is renormalizable, which gives rise to a non-degenerate Dirac neutrino Yukawa matrix and an unique CP-phase, and which in turn explains the non-zero value of $\theta_{13}\simeq9^{\circ}$ and two large mixing angles $\theta_{12}, \theta_{23}$. We show that the spontaneously generated CP phase "$\xi$" could become a natural source of leptogenesis as well as CP violations in the CKM and Pontecorvo-Maki-Nakagawa-Sakata (PMNS). Moreover, we provide a solution for the strong CP problem. Interestingly enough, we show that, for around $\xi\simeq120^{\circ}$, the quarks lead to the correct CKM CP-phase corresponding to $\delta^{q}_{CP}\simeq67^{\circ}$, while the leptons with the measured value of $\theta_{13}$ favor $\delta_{CP}=$, $|\theta_{23}-45^{\circ}|\rightarrow0$ for normal mass hierarchy and $\delta_{CP}=$, $|\theta_{23}-45^{\circ}|\rightarrow5^{\circ}$ for inverted one. As a numerical study in the lepton sector, we show low-energy phenomenologies and leptogenesis for the normal and inverted case, respectively, and a link between them.
hep-ph/9812202
Jay Watson
N.J. Watson
The Pinch Technique Beyond One Loop: The Gauge-Independent Two-Loop Quark Self-Energy
45 pages, 18 figures, Latex
Nucl.Phys.B552:461-507,1999
10.1016/S0550-3213(99)00197-2
null
hep-ph hep-th
null
It is shown how the pinch technique algorithm may be consistently extended beyond the one-loop level to obtain the gauge-independent two-loop fermion self-energy -i\hat\Sigma^(2)(p) in QCD in the pinch technique approach. The starting point for the construction is the general diagrammatic representation of the two-loop quark self-energy in terms of renormalized one-loop two- and three-point function and tree level Bethe-Salpeter-type quark-gluon scattering kernel insertions in the one-loop quark self-energy. Using factors of longitudinal gluon four-momentum only from lowest order gauge field propagators and triple gauge vertices to trigger the relevant Ward identities, the function -i\hat\Sigma^(2)(p) is explicitly constructed from the consideration of the two-loop QCD corrections to the Compton scattering of a photon off a quark. It is shown that the resulting pinch technique self-energy -i\hat\Sigma^(2)(p) is gauge-independent at all momenta, does not shift the position of the propagator pole and is multiplicatively renormalizable by local counterterms. The demonstration of the gauge independence is based on an efficient diagrammatic method to deal with the several dozen two-loop diagrams involved. It is explicitly shown by this example that the general correspondence between the pinch technique n-point functions and those obtained in the background field method in the Feynman quantum gauge \xi_{Q} = 1 does not persist beyond one loop.
[ { "created": "Tue, 1 Dec 1998 01:46:18 GMT", "version": "v1" } ]
2011-07-19
[ [ "Watson", "N. J.", "" ] ]
It is shown how the pinch technique algorithm may be consistently extended beyond the one-loop level to obtain the gauge-independent two-loop fermion self-energy -i\hat\Sigma^(2)(p) in QCD in the pinch technique approach. The starting point for the construction is the general diagrammatic representation of the two-loop quark self-energy in terms of renormalized one-loop two- and three-point function and tree level Bethe-Salpeter-type quark-gluon scattering kernel insertions in the one-loop quark self-energy. Using factors of longitudinal gluon four-momentum only from lowest order gauge field propagators and triple gauge vertices to trigger the relevant Ward identities, the function -i\hat\Sigma^(2)(p) is explicitly constructed from the consideration of the two-loop QCD corrections to the Compton scattering of a photon off a quark. It is shown that the resulting pinch technique self-energy -i\hat\Sigma^(2)(p) is gauge-independent at all momenta, does not shift the position of the propagator pole and is multiplicatively renormalizable by local counterterms. The demonstration of the gauge independence is based on an efficient diagrammatic method to deal with the several dozen two-loop diagrams involved. It is explicitly shown by this example that the general correspondence between the pinch technique n-point functions and those obtained in the background field method in the Feynman quantum gauge \xi_{Q} = 1 does not persist beyond one loop.
1207.2529
Pavel Fileviez Perez
Jonathan M. Arnold (Caltech), Pavel Fileviez Perez (CCPP, NYU), Bartosz Fornal (Caltech)
Supersymmetric Dark Matter Sectors
minor corrections, to appear in Physics Letters B
Phys.Lett. B718 (2012) 75-79
10.1016/j.physletb.2012.09.066
null
hep-ph astro-ph.CO hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the properties of a dark matter sector where supersymmetry is a good symmetry. In this context we find that the stability of the dark matter candidate is possible even when R-parity is broken in the visible sector. In order to illustrate the idea we investigate a simple scenario where the dark matter candidate is the lightest scalar field in the dark sector which annihilates mainly into two sfermions when these channels are available. We study the relic density constraints and the predictions for the dark matter detection experiments.
[ { "created": "Wed, 11 Jul 2012 02:09:25 GMT", "version": "v1" }, { "created": "Sat, 6 Oct 2012 13:12:19 GMT", "version": "v2" } ]
2012-10-31
[ [ "Arnold", "Jonathan M.", "", "Caltech" ], [ "Perez", "Pavel Fileviez", "", "CCPP, NYU" ], [ "Fornal", "Bartosz", "", "Caltech" ] ]
We investigate the properties of a dark matter sector where supersymmetry is a good symmetry. In this context we find that the stability of the dark matter candidate is possible even when R-parity is broken in the visible sector. In order to illustrate the idea we investigate a simple scenario where the dark matter candidate is the lightest scalar field in the dark sector which annihilates mainly into two sfermions when these channels are available. We study the relic density constraints and the predictions for the dark matter detection experiments.
2004.12189
P. Divari C.
Paraskevi C. Divari
Supernova neutrino scattering off Gadolinium odd isotopes in water Cherenkov detectors
10 pages, 5 figures, 2 Tables. arXiv admin note: substantial text overlap with arXiv:1808.01677; text overlap with arXiv:nucl-th/9709006 by other authors
null
10.1088/1475-7516/2020/07/008
null
hep-ph astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, the supernova neutrino(SN) charged-current interactions with Gd odd isotopes (A=155 and 157) are studied. We use measured spectra and the quasiparticle-phonon model (MQPM) to calculate the charged current response of odd Gd isotopes to supernova neutrinos. Flux-averaged cross-sections are obtained considering quasi-thermal neutrino spectra.
[ { "created": "Sat, 25 Apr 2020 17:05:51 GMT", "version": "v1" }, { "created": "Thu, 21 May 2020 09:29:50 GMT", "version": "v2" } ]
2020-07-22
[ [ "Divari", "Paraskevi C.", "" ] ]
In this work, the supernova neutrino(SN) charged-current interactions with Gd odd isotopes (A=155 and 157) are studied. We use measured spectra and the quasiparticle-phonon model (MQPM) to calculate the charged current response of odd Gd isotopes to supernova neutrinos. Flux-averaged cross-sections are obtained considering quasi-thermal neutrino spectra.
hep-ph/0609298
Martin White Mr
C. G. Lester, M. A. Parker and M. J. White
Three body kinematic endpoints in SUSY models with non-universal Higgs masses
21 pages, 13 figures, updated the preprint number to reflect status as an ATLAS scientific note
JHEP 0710:051,2007
10.1088/1126-6708/2007/10/051
Cavendish-HEP-2005-21, SN-ATLAS-2006-058
hep-ph
null
We derive and present expressions for the kinematic endpoints that arise in the invariant mass distributions of visible decay products of cascade decays featuring a two body decay followed by a three body decay. This is an extension of a current technique that addresses chains of successive two body decays. We then apply these to a supergravity model with Non-Universal Higgs Masses (NUHM), having simulated a data set using the ATLFAST detector simulation. We find that, should such a model be chosen by nature, the endpoints will be visible in ATLAS data, and we discuss the problems associated with mass reconstruction in models with a similar phenomenology.
[ { "created": "Thu, 28 Sep 2006 16:52:24 GMT", "version": "v1" }, { "created": "Fri, 29 Sep 2006 10:45:12 GMT", "version": "v2" }, { "created": "Tue, 28 Aug 2007 13:32:53 GMT", "version": "v3" } ]
2009-04-15
[ [ "Lester", "C. G.", "" ], [ "Parker", "M. A.", "" ], [ "White", "M. J.", "" ] ]
We derive and present expressions for the kinematic endpoints that arise in the invariant mass distributions of visible decay products of cascade decays featuring a two body decay followed by a three body decay. This is an extension of a current technique that addresses chains of successive two body decays. We then apply these to a supergravity model with Non-Universal Higgs Masses (NUHM), having simulated a data set using the ATLFAST detector simulation. We find that, should such a model be chosen by nature, the endpoints will be visible in ATLAS data, and we discuss the problems associated with mass reconstruction in models with a similar phenomenology.
2112.09713
Alberto Tonero Dr.
Wafia Bensalem, David London, Daniel Stolarski and Alberto Tonero
Searching for light new physics at the LHC via lepton-number violation
23 pages, 4 figures, 5 tables
null
10.1007/JHEP04(2022)049
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We study the collider phenomenology of a simplified model containing a right-handed $W$ in which the $W_R$ couples predominantly to the third generation in the quark sector. The model also includes a light Majorana neutrino, with $M_1\sim {\cal O}(100)$ GeV, giving rise to lepton-number-violating signatures that are visible at the LHC. Taking into account all the searches from the LHC and Tevatron, we find that this $W_R$ can still be as light as $M_R \sim 300$ GeV. We show that this type of new physics, and others like it, can be detected at the LHC using final states with three same-sign same-flavour leptons.
[ { "created": "Fri, 17 Dec 2021 19:00:04 GMT", "version": "v1" } ]
2022-04-27
[ [ "Bensalem", "Wafia", "" ], [ "London", "David", "" ], [ "Stolarski", "Daniel", "" ], [ "Tonero", "Alberto", "" ] ]
We study the collider phenomenology of a simplified model containing a right-handed $W$ in which the $W_R$ couples predominantly to the third generation in the quark sector. The model also includes a light Majorana neutrino, with $M_1\sim {\cal O}(100)$ GeV, giving rise to lepton-number-violating signatures that are visible at the LHC. Taking into account all the searches from the LHC and Tevatron, we find that this $W_R$ can still be as light as $M_R \sim 300$ GeV. We show that this type of new physics, and others like it, can be detected at the LHC using final states with three same-sign same-flavour leptons.
0909.4843
Manmohan Gupta
Neelu Mahajan, Rohit Verma, Manmohan Gupta
Investigating non-Fritzsch like texture specific quark mass matrices
13 pages, 4 figures, Accepted for publication in IJMPA
null
10.1142/S0217751X1004841X
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A detailed investigation of all possible textures of Fritzsch-like and non-Fritzsch like, 144 for texture 6 zero and 432 for texture 5 zero mass matrices, have been carried out to ascertain their compatibility with the existing quark mixing data. It seems that all the texture 6 zero possibilities are completely ruled out whereas in the case of texture 5 zero mass matrices the only viable possibility looks to be that of Fritzsch-like.
[ { "created": "Sat, 26 Sep 2009 06:48:16 GMT", "version": "v1" }, { "created": "Mon, 19 Apr 2010 06:35:40 GMT", "version": "v2" } ]
2015-05-14
[ [ "Mahajan", "Neelu", "" ], [ "Verma", "Rohit", "" ], [ "Gupta", "Manmohan", "" ] ]
A detailed investigation of all possible textures of Fritzsch-like and non-Fritzsch like, 144 for texture 6 zero and 432 for texture 5 zero mass matrices, have been carried out to ascertain their compatibility with the existing quark mixing data. It seems that all the texture 6 zero possibilities are completely ruled out whereas in the case of texture 5 zero mass matrices the only viable possibility looks to be that of Fritzsch-like.
hep-ph/0701267
Johan Bijnens
Johan Bijnens, Niclas Danielsson and Timo A. Lahde
Partially Quenched and Three Flavour ChPT at Two Loops
11 pages, invited talk at ``Final Euridice Meeting'', August 24-28 2006, Kazimierz, Poland
ActaPhys.Polon.B38:2777-2788,2007
null
LU TP 07-03, NT@UW-07-02
hep-ph
null
A summary of recent progress in Chiral Perturbation Theory (ChPT) at the two-loop level is given. A short introduction to ChPT is included, along with an explanation of the usefulness of developing ChPT for partially quenched QCD. Further, our recent work in partially quenched ChPT is reviewed, and a few comments are given on older work in mesonic ChPT at the two-loop level. In particular, we quote the present best values for the low-energy constants of the $\mathcal{O}(p^4)$ chiral Lagrangian.
[ { "created": "Wed, 31 Jan 2007 11:13:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bijnens", "Johan", "" ], [ "Danielsson", "Niclas", "" ], [ "Lahde", "Timo A.", "" ] ]
A summary of recent progress in Chiral Perturbation Theory (ChPT) at the two-loop level is given. A short introduction to ChPT is included, along with an explanation of the usefulness of developing ChPT for partially quenched QCD. Further, our recent work in partially quenched ChPT is reviewed, and a few comments are given on older work in mesonic ChPT at the two-loop level. In particular, we quote the present best values for the low-energy constants of the $\mathcal{O}(p^4)$ chiral Lagrangian.
0809.2440
Seong Chan Park
Seong Chan Park
Inflation in the nonminimal theory with `K(phi)R' term
3 pages, 1 figure, Talk given at 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY08), Seoul, Korea, 16-21 Jun 2008
AIP Conf.Proc.1078:524-526,2009
10.1063/1.3052016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A class of inflationary models with the nonminimal coupling term `K(phi)R' is considered. We show that the successful inflation can take place if the ratio between the square of the nonminimal coupling term and the potential for the scalar goes asymptotically constant.
[ { "created": "Mon, 15 Sep 2008 17:44:42 GMT", "version": "v1" } ]
2009-02-02
[ [ "Park", "Seong Chan", "" ] ]
A class of inflationary models with the nonminimal coupling term `K(phi)R' is considered. We show that the successful inflation can take place if the ratio between the square of the nonminimal coupling term and the potential for the scalar goes asymptotically constant.
hep-ph/9602289
Marcelo Gleiser
Marcelo Gleiser
The Origin of Baryonic Matter in the Universe: A Brief Review
15 pages, revtex, no figures. Plenary talk presented at the Brazilian Meeting on Particles and Fields, Caxambu, October 1995
null
10.1063/1.53231
DART-HEP-96/02
hep-ph astro-ph
null
I briefly review the main ideas and challenges involved in the computation of the observed baryonic asymmetry of the Universe.
[ { "created": "Tue, 13 Feb 1996 13:53:59 GMT", "version": "v1" } ]
2009-10-28
[ [ "Gleiser", "Marcelo", "" ] ]
I briefly review the main ideas and challenges involved in the computation of the observed baryonic asymmetry of the Universe.
0807.1121
Tomasz Pierzcha{\l}a
Tomasz Pierzchala, Krzysztof Piotrzkowski
Sensitivity to anomalous quartic gauge couplings in photon-photon interactions at the LHC
8 pages and 11 figures, Contribution to the CERN workshop on "High energy photon collisions at the LHC", 22-25 April 2008
Nucl.Phys.Proc.Suppl.179-180:257-264,2008
10.1016/j.nuclphysbps.2008.07.032
CP3-08-32
hep-ph hep-ex
http://creativecommons.org/licenses/publicdomain/
The exclusive two-photon production at the LHC of pairs of W and Z bosons provides a novel and unique test-ground for the electroweak gauge boson sector. In particular it offers, thanks to high gamma-gamma center-of-mass energies, large and direct sensitivity to the anomalous quartic gauge couplings otherwise very difficult to investigate at the LHC. An initial analysis has been performed assuming leptonic decays and generic acceptance cuts. Simulation of a simple counting experiment has shown for the integrated luminosity of 10 fb-1 at least four thousand times larger sensitivity to the genuine quartic couplings, a_0^W, a_0^Z, a_C^W and a_C^Z, than those obtained at LEP. The impact of the unitarity constraints on the estimated limits has been studied using the dipole form-factors. Finally, differential distributions of the decay leptons have been provided to illustrate the potential for further improvements of the sensitivities.
[ { "created": "Mon, 7 Jul 2008 20:36:10 GMT", "version": "v1" } ]
2009-02-05
[ [ "Pierzchala", "Tomasz", "" ], [ "Piotrzkowski", "Krzysztof", "" ] ]
The exclusive two-photon production at the LHC of pairs of W and Z bosons provides a novel and unique test-ground for the electroweak gauge boson sector. In particular it offers, thanks to high gamma-gamma center-of-mass energies, large and direct sensitivity to the anomalous quartic gauge couplings otherwise very difficult to investigate at the LHC. An initial analysis has been performed assuming leptonic decays and generic acceptance cuts. Simulation of a simple counting experiment has shown for the integrated luminosity of 10 fb-1 at least four thousand times larger sensitivity to the genuine quartic couplings, a_0^W, a_0^Z, a_C^W and a_C^Z, than those obtained at LEP. The impact of the unitarity constraints on the estimated limits has been studied using the dipole form-factors. Finally, differential distributions of the decay leptons have been provided to illustrate the potential for further improvements of the sensitivities.
hep-ph/9909364
Marc Besancon
M. Besancon (CEA-Saclay-Dapnia)
Looking for extra-dimensions at the weak scale: experimental search for Kaluza-Klein states signatures at the e+e- linear collider
6 pages, 3 figures, corrected some typos
null
null
null
hep-ph
null
An experimental search for signatures of Kaluza-Klein graviton states at the 500 GeV e+e- linear collider, in which the graviton states are produced in association with a photon, is presented. The study of the signal extraction is performed with the help of Monte Carlo simulations
[ { "created": "Tue, 14 Sep 1999 14:41:03 GMT", "version": "v1" }, { "created": "Thu, 16 Sep 1999 08:32:09 GMT", "version": "v2" }, { "created": "Mon, 20 Sep 1999 14:01:06 GMT", "version": "v3" } ]
2007-05-23
[ [ "Besancon", "M.", "", "CEA-Saclay-Dapnia" ] ]
An experimental search for signatures of Kaluza-Klein graviton states at the 500 GeV e+e- linear collider, in which the graviton states are produced in association with a photon, is presented. The study of the signal extraction is performed with the help of Monte Carlo simulations
2206.14667
Javier Mazzitelli
Javier Mazzitelli
NNLO study of top-quark mass renormalization scheme uncertainties in Higgs boson production
15 pages, 4 figures. v2: added some references, minor changes in the text
null
10.1007/JHEP09(2022)065
MPP-2022-63
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ambiguity in the choice of a renormalization scheme and scale for the top-quark mass leads to an additional source of theoretical uncertainty in the calculation of the Higgs boson production cross section via gluon fusion. These uncertainties were found to be dominant in the case of off-shell Higgs production at next-to-leading order in QCD for large values of the Higgs virtuality $m_H^*$. In this work, we study the uncertainties related to the top-quark mass definition up to next-to-next-to-leading order (NNLO) in QCD. We include the full top-quark mass dependence up to three loops in the virtual corrections, and evaluate the real contributions in the soft limit, therefore obtaining the so-called soft-virtual (SV) approximation. We construct NNLO-SV predictions for off-shell Higgs boson production renormalizing the top-quark mass within both the on-shell (OS) and the MSbar schemes, and study in detail the differences between them. While the differences between the two schemes are sizeable, we find that the predictions are always compatible within scale uncertainties. We also observe that the difference between renormalization schemes is largely reduced when increasing the order of the perturbative expansion. We analyze the quality of the convergence of the perturbative series in both schemes, and find that at large invariant masses the MSbar results present much larger corrections than their OS counterparts. We also comment on the more complicated case of Higgs boson pair production.
[ { "created": "Wed, 29 Jun 2022 14:12:53 GMT", "version": "v1" }, { "created": "Mon, 19 Dec 2022 10:32:20 GMT", "version": "v2" } ]
2022-12-20
[ [ "Mazzitelli", "Javier", "" ] ]
The ambiguity in the choice of a renormalization scheme and scale for the top-quark mass leads to an additional source of theoretical uncertainty in the calculation of the Higgs boson production cross section via gluon fusion. These uncertainties were found to be dominant in the case of off-shell Higgs production at next-to-leading order in QCD for large values of the Higgs virtuality $m_H^*$. In this work, we study the uncertainties related to the top-quark mass definition up to next-to-next-to-leading order (NNLO) in QCD. We include the full top-quark mass dependence up to three loops in the virtual corrections, and evaluate the real contributions in the soft limit, therefore obtaining the so-called soft-virtual (SV) approximation. We construct NNLO-SV predictions for off-shell Higgs boson production renormalizing the top-quark mass within both the on-shell (OS) and the MSbar schemes, and study in detail the differences between them. While the differences between the two schemes are sizeable, we find that the predictions are always compatible within scale uncertainties. We also observe that the difference between renormalization schemes is largely reduced when increasing the order of the perturbative expansion. We analyze the quality of the convergence of the perturbative series in both schemes, and find that at large invariant masses the MSbar results present much larger corrections than their OS counterparts. We also comment on the more complicated case of Higgs boson pair production.
1307.7611
Stefan Floerchinger
Stefan Floerchinger and Urs Achim Wiedemann
Characterization of initial fluctuations for the hydrodynamical description of heavy ion collisions
40 pages, 16 figures
Phys. Rev. C 88, 044906 (2013)
10.1103/PhysRevC.88.044906
CERN-PH-TH/2013-179
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Event-by-event fluctuations in the initial conditions for a hydrodynamical description of heavy-ion collisions are characterized. We propose a Bessel-Fourier decomposition with respect to the azimuthal angle, the radius in the transverse plane and rapidity. This allows for a complete characterization of fluctuations in all hydrodynamical fields including energy density, pressure, fluid velocity, shear stress and bulk viscous pressure. It has the advantage that fluctuations can be ordered with respect to their wave length and that they can be propagated mode-by-mode within the hydrodynamical formalism. Event ensembles can then be characterized in terms of a functional probability distribution. For the event ensemble of a Monte Carlo Glauber model, we provide evidence that the latter is close to Gaussian form, thus allowing for a particularly simple characterization of the event distribution.
[ { "created": "Mon, 29 Jul 2013 15:16:10 GMT", "version": "v1" } ]
2013-10-30
[ [ "Floerchinger", "Stefan", "" ], [ "Wiedemann", "Urs Achim", "" ] ]
Event-by-event fluctuations in the initial conditions for a hydrodynamical description of heavy-ion collisions are characterized. We propose a Bessel-Fourier decomposition with respect to the azimuthal angle, the radius in the transverse plane and rapidity. This allows for a complete characterization of fluctuations in all hydrodynamical fields including energy density, pressure, fluid velocity, shear stress and bulk viscous pressure. It has the advantage that fluctuations can be ordered with respect to their wave length and that they can be propagated mode-by-mode within the hydrodynamical formalism. Event ensembles can then be characterized in terms of a functional probability distribution. For the event ensemble of a Monte Carlo Glauber model, we provide evidence that the latter is close to Gaussian form, thus allowing for a particularly simple characterization of the event distribution.
hep-ph/0604154
Rabindra N. Mohapatra
Ken Hsieh, R.N. Mohapatra and Salah Nasri
Dark Matter in Universal Extra Dimension Models: $\gamma_{KK}$ vrs $\nu_{R,KK}$
13 pages, 2 figures; minor changes; to appear in Phys. Rev.D
Phys.Rev.D74:066004,2006
10.1103/PhysRevD.74.066004
UMD-PP-06-004
hep-ph
null
We show that in a class of universal extra dimension models (UED), which solves both the neutrino mass and proton decay problem, an admixture of KK photon and KK right handed neutrinos can provide the required amount of cold dark matter (CDM). This model has two parameters $R^{-1}$ and $M_{Z'}$ ($R$ is the radius of the extra space dimensions and $Z'$ the extra neutral gauge boson of the model). Using the value of the relic CDM density, combined with the results from the cryogenic searches for CDM, we obtain upper limits on $R^{-1}$ of about 400-650 GeV and $M_{Z'}\leq 1.5$ TeV, both being accessible to LHC. In some regions of the parameter space, the dark matter-nucleon scattering cross section can be as high as of $10^{-44}$ cm$^2$, which can be probed by the next round of dark matter search experiments.
[ { "created": "Tue, 18 Apr 2006 19:07:06 GMT", "version": "v1" }, { "created": "Fri, 1 Sep 2006 17:20:28 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hsieh", "Ken", "" ], [ "Mohapatra", "R. N.", "" ], [ "Nasri", "Salah", "" ] ]
We show that in a class of universal extra dimension models (UED), which solves both the neutrino mass and proton decay problem, an admixture of KK photon and KK right handed neutrinos can provide the required amount of cold dark matter (CDM). This model has two parameters $R^{-1}$ and $M_{Z'}$ ($R$ is the radius of the extra space dimensions and $Z'$ the extra neutral gauge boson of the model). Using the value of the relic CDM density, combined with the results from the cryogenic searches for CDM, we obtain upper limits on $R^{-1}$ of about 400-650 GeV and $M_{Z'}\leq 1.5$ TeV, both being accessible to LHC. In some regions of the parameter space, the dark matter-nucleon scattering cross section can be as high as of $10^{-44}$ cm$^2$, which can be probed by the next round of dark matter search experiments.
hep-ph/0101047
Jean-Marc Laget
J.-M. Laget
Strangeness Production by Electromagnetic and Hadronic Probes
10 pages, 9 figures; Invited talk at HYP2000 Conference, Torino, Italy, 23-27 October 2000. To appear in Nucl. Phys. A
Nucl.Phys. A691 (2001) 11-20
10.1016/S0375-9474(01)00996-4
null
hep-ph
null
After pioneering works on hypernuclei, strangeness production mechanisms have been studied in hadron collisions and photoreactions in the sixties. Recent experiments at SATURNE and COSY, in the hadronic sector, as well as ELSA and JLab, in the electromagnetic sector, have confirmed our basic ideas on the reaction mechanisms. In the near future, strangeness production at JLab, HERMES and COMPASS may prove to be a powerful tool to study hadronic matter.
[ { "created": "Fri, 5 Jan 2001 10:49:57 GMT", "version": "v1" } ]
2009-11-07
[ [ "Laget", "J. -M.", "" ] ]
After pioneering works on hypernuclei, strangeness production mechanisms have been studied in hadron collisions and photoreactions in the sixties. Recent experiments at SATURNE and COSY, in the hadronic sector, as well as ELSA and JLab, in the electromagnetic sector, have confirmed our basic ideas on the reaction mechanisms. In the near future, strangeness production at JLab, HERMES and COMPASS may prove to be a powerful tool to study hadronic matter.
hep-ph/9809463
Grzegorz Wilk
G.Wilk and Z.Wlodarczyk
Do we observe L\'evy flights in cosmic rays?
LaTeX file and 1 LaTeX file with figure. Uses espcrc2.sty (included) and LaTeX2e. 4 pages
null
10.1016/S0920-5632(99)00239-X
null
hep-ph cond-mat nucl-th
null
We argue that the so called long flying component (LFC) observed in some cosmic ray experiments are yet another manifestation of L\'evy distributions (with index $q=1.3$), this time of the distribution observation probability of the depths of starting points of cascades. It means that LFC is governed by the so called long-tail L\'evy-like anomalous superdiffusion, a phenomenon frequently encountered in Nature. Its connection with the so called Tsallis's statistics is also briefly discussed.
[ { "created": "Mon, 21 Sep 1998 10:17:36 GMT", "version": "v1" } ]
2009-10-31
[ [ "Wilk", "G.", "" ], [ "Wlodarczyk", "Z.", "" ] ]
We argue that the so called long flying component (LFC) observed in some cosmic ray experiments are yet another manifestation of L\'evy distributions (with index $q=1.3$), this time of the distribution observation probability of the depths of starting points of cascades. It means that LFC is governed by the so called long-tail L\'evy-like anomalous superdiffusion, a phenomenon frequently encountered in Nature. Its connection with the so called Tsallis's statistics is also briefly discussed.
hep-ph/9607228
null
A.B. Arbuzov (JINR, Dubna), V.S. Fadin (INP, Novosibirsk) E.A. Kuraev (JINR, Dubna), L.N. Lipatov (INP, St.-Petersburg), N.P. Merenkov (Phys.-Tech. Inst., Kharkov), L.G. Trentadue (Univ. & INFN Parma)
Small-Angle Bhabha Scattering
10 pages, Latex file epsfig.sty
Nucl.Phys.Proc.Suppl. 51C (1996) 154-163
10.1016/S0920-5632(96)90020-1
UPRF-96-476
hep-ph
null
We present the calculation of the elastic and inelastic high--energy small--angle electron--positron scattering with a {\it per mille} accuracy. PACS numbers 12.15.Lk, 12.20.--m, 12.20.Ds, 13.40.--f
[ { "created": "Wed, 3 Jul 1996 09:55:00 GMT", "version": "v1" } ]
2015-06-25
[ [ "Arbuzov", "A. B.", "", "JINR, Dubna" ], [ "Fadin", "V. S.", "", "INP, Novosibirsk" ], [ "Kuraev", "E. A.", "", "JINR, Dubna" ], [ "Lipatov", "L. N.", "", "INP, St.-Petersburg" ], [ "Merenkov", "N. P.", "", "Phys.-Tech.\n Inst., Kharkov" ], [ "Trentadue", "L. G.", "", "Univ. & INFN Parma" ] ]
We present the calculation of the elastic and inelastic high--energy small--angle electron--positron scattering with a {\it per mille} accuracy. PACS numbers 12.15.Lk, 12.20.--m, 12.20.Ds, 13.40.--f
hep-ph/9506463
null
Kacper Zalewski
Structure and Decays of Particles Containing Heavy Quarks (Theory)
12 pages, Proceedings of the conference Physics in Collision 1995
null
null
null
hep-ph
null
Some recent results and problems in the theory of particles containing heavy quarks ar reviewed.
[ { "created": "Fri, 30 Jun 1995 09:42:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zalewski", "Kacper", "" ] ]
Some recent results and problems in the theory of particles containing heavy quarks ar reviewed.
1109.0512
Marco Taoso
Diego Restrepo, Marco Taoso, J. W. F. Valle, Oscar Zapata
Gravitino dark matter and neutrino masses with bilinear R-parity violation
10 pages, 4 figures, match the published version
Phys. Rev. D 85, 023523 (2012)
10.1103/PhysRevD.85.023523
IFIC/11-41
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bilinear R-parity violation provides an attractive origin for neutrino masses and mixings. In such schemes the gravitino is a viable decaying dark matter particle whose R-parity violating decays lead to monochromatic photons with rates accessible to astrophysical observations. We determine the parameter region allowed by gamma-ray line searches, dark matter relic abundance and neutrino oscillation data, obtaining a limit on the gravitino mass $m_{\tilde G} \lsim$ 1-10 GeV corresponding to a relatively low reheat temperature $T_R \lsim$ few $\times 10^7-10^8$ GeV. Neutrino mass and mixing parameters may be reconstructed at accelerator experiments like the Large Hadron Collider.
[ { "created": "Fri, 2 Sep 2011 18:09:32 GMT", "version": "v1" }, { "created": "Wed, 1 Feb 2012 02:34:06 GMT", "version": "v2" } ]
2013-05-30
[ [ "Restrepo", "Diego", "" ], [ "Taoso", "Marco", "" ], [ "Valle", "J. W. F.", "" ], [ "Zapata", "Oscar", "" ] ]
Bilinear R-parity violation provides an attractive origin for neutrino masses and mixings. In such schemes the gravitino is a viable decaying dark matter particle whose R-parity violating decays lead to monochromatic photons with rates accessible to astrophysical observations. We determine the parameter region allowed by gamma-ray line searches, dark matter relic abundance and neutrino oscillation data, obtaining a limit on the gravitino mass $m_{\tilde G} \lsim$ 1-10 GeV corresponding to a relatively low reheat temperature $T_R \lsim$ few $\times 10^7-10^8$ GeV. Neutrino mass and mixing parameters may be reconstructed at accelerator experiments like the Large Hadron Collider.