Physical sciences topic list of research papers
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Unstable relics as a source of galactic positrons
Abstract We calculate the fluxes of 511 keV photons from the galactic bulge caused by positrons produced in the decays of relic particles with masses less than 100 MeV. In particular, we tighten the constraints on sterile neutrinos over a large...
2004 / Charles Picciotto, Maxim Pospelov -
Natural gauge and gravitational coupling unification and the superpartner masses
Abstract The possibility to achieve unification at the string scale in the context of the simplest supersymmetric grand unified theory is investigated. We find conservative upper bounds on the superpartner masses consistent with the unification of...
2007 / David Emmanuel-Costa, Pavel Fileviez Pérez, Ricardo González Felipe -
Inheritance principle and non-renormalization theorems at finite temperature
Abstract We present a general proof of an “inheritance principle” satisfied by a weakly coupled SU ( N ) gauge theory with adjoint ...
2006 / Mauro Brigante, Guido Festuccia, Hong Liu -
Noncommutative geometry inspired Schwarzschild black hole
Abstract We investigate the behavior of a noncommutative radiating Schwarzschild black hole. It is shown that coordinate noncommutativity cures usual problems encountered in the description of the terminal phase of black hole evaporation. More in...
2005 / Piero Nicolini, Anais Smailagic, Euro Spallucci -
Medium effects in ρ-meson photoproduction
Abstract We compute dilepton invariant mass spectra from the decays of ρ mesons produced by photon reactions off nuclei. Our calculations employ a realistic model for the ρ photoproduction amplitude on the nucleon which provides fair agreement with...
2009 / F. Riek, R. Rapp, T.-S.H. Lee, Yongseok Oh -
Lepton dipole moments in extended technicolor models
Abstract We analyze the diagonal and transition magnetic and electric dipole moments of charged leptons in extended technicolor (ETC) models, taking account of the multiscale nature of the ETC gauge symmetry breaking, conformal (walking) behavior of ...
2004 / Thomas Appelquist, Maurizio Piai, Robert Shrock -
A study of the sign problem for lattice QCD with chemical potential
Abstract We study the expectation value of the phase of the fermion determinant for Wilson lattice fermions with chemical potential. We use quenched SU ( 3 ...
2009 / Julia Danzer, Christof Gattringer, Ludovit Liptak, Marina Marinkovic -
Resonant production of color octet electron at the LHeC
Abstract In composite models with colored preons leptogluons ( l 8 ) has a same status with leptoquarks, excited leptons and ...
2010 / M. Sahin, S. Sultansoy, S. Turkoz -
k-essential phantom energy: doomsday around the corner?
Abstract In spite of its rather weird properties which include violation of the dominant-energy condition, the requirement of superluminal sound speed and increasing vacuum-energy density, phantom energy has recently attracted a lot of scientific...
2004 / Pedro F. González-Dı́az -
A model of holographic dark energy
Abstract A model for holographic dark energy is proposed, following the idea that the short distance cut-off is related to the infrared cut-off. We assume that the infrared cut-off relevant to the dark energy is the size of the event horizon. With...
2004 / Miao Li -
QCD corrections to γγ→ZZ at small scattering angles
Abstract QCD corrections to the electroweak cross section of γγ→ZZ at high energies and small scattering angles have been calculated. The dominant contributions are due to t-channel gluon exchange, i.e., photons dissociate into quark–antiquark pairs ...
2003 / Grigorios Chachamis, Krisztián Peters -
Time variable cosmological constants from the age of universe
Abstract In this Letter, time variable cosmological constant, dubbed age cosmological constant, is investigated motivated by the fact: any cosmological length scale and time scale can introduce a cosmological constant or vacuum energy density into...
2010 / Lixin Xu, Jianbo Lu, Wenbo Li -
Geometrical loci and CFTs via the Virasoro symmetry of the mKdV-SG hierarchy: an excursus
Abstract We will describe the appearance of specific algebraic KdV potentials as a consequence of a requirement on an integro-differential expression. This expression belongs to a class generated by means of Virasoro vector fields acting on the KdV...
2005 / Davide Fioravanti -
Monte Carlo studies of the GWW phase transition in large-N gauge theories
Abstract In the study of the small ten-dimensional Schwarzschild black hole, the black hole to string transition is an important problem. In [L. Alvarez-Gaumé, P. Basu, M. Marino, S.R. Wadia, Eur. Phys. J. C 48 (2006) 647 hep-th/0605041], a possible ...
2007 / Takehiro Azuma, Pallab Basu, Spenta R. Wadia -
Gluon condensates and c, b quark masses from quarkonia ratios of moments
Abstract We extract (for the first time) the ratio of the gluon condensate 〈 g 3 ...
2010 / Stephan Narison -
Gluon confinement criterion in QCD
Abstract We fix exactly and uniquely the infrared structure of the full gluon propagator in QCD, not solving explicitly the corresponding dynamical equation of motion. By construction, this structure is an infinite sum over all possible severe...
2004 / V. Gogohia -
Domain wall universe in the Einstein–Born–Infeld theory
Abstract In this Letter, we discuss the dynamics of a domain wall universe embedded into the charged black hole spacetime of the Einstein–Born–Infeld (EBI) theory. There are four kinds of possible spacetime structures, i.e., those with no horizon,...
2009 / Bum-Hoon Lee, Wonwoo Lee, Masato Minamitsuji -
Platonic gravitating skyrmions
Abstract We construct globally regular gravitating skyrmions, which possess only discrete symmetries. In particular, we present tetrahedral and cubic skyrmions. The SU ( 2 ...
2006 / Theodora Ioannidou, Burkhard Kleihaus, Jutta Kunz -
Dark energy as an off-shell tachyon background in four-dimensional strings
Abstract We consider a time-dependent bosonic string in graviton, dilaton and tachyon backgrounds, for which it was already shown that conformal invariance is respected to all orders in α ...
2009 / J. Alexandre, N.E. Mavromatos -
Minimal flavour violation and multi-Higgs models
Abstract We propose an extension of the hypothesis of Minimal Flavour Violation (MFV) to general multi-Higgs models without the assumption of Natural Flavour Conservation (NFC) in the Higgs sector. We study in detail under what conditions the...
2010 / F.J. Botella, G.C. Branco, M.N. Rebelo