11,191 research outputs found
The QCD Pomeron in Ultraperipheral Heavy Ion Collisions: IV. Photonuclear Production of Vector Mesons
The photonuclear production of vector mesons in ultraperipheral heavy ion
collisions is investigated within the QCD color dipole picture, with particular
emphasis on the saturation model. The integrated cross section and the rapidity
distribution for the A + A --> V + A + A (V = rho, omega, phi, J/Psi) process
are computed and theoretical estimates for scattering on both light and heavy
nuclei are given for energies of RHIC and LHC. A comparison with the recent
STAR data on coherent production of rho mesons is also presented. Furthermore,
we calculate the photoproduction of vector mesons in proton-proton collisions
at RHIC, Tevatron and LHC energies.Comment: 19 pages, 6 figures and 2 tables. Version to be published in Eur.
Phys. J.
Inelastic quarkonium photoproduction in coherent hadron - hadron interactions at LHC energies
In this paper we study the inelastic quarkonium photoproduction in coherent
interactions. Considering the ultra relativistic hadrons as a
source of photons, we estimate the total ( and ) cross sections and rapidity distributions at
LHC energies. Our results demonstrate that the experimental analysis of this
process can be used to understand the underlying mechanism governing heavy
quarkonium production.Comment: 9 pages, 7 figures, 3 table
Black hole formation from massive scalar field collapse in the Einstein-de Sitter universe
We study the spherically symmetric collapse of a real, minimally coupled,
massive scalar field in an asymptotically Einstein-de Sitter spacetime
background. By means of an eikonal approximation for the field and metric
functions, we obtain a simple analytical criterion---involving the physical
size and mass scales (the field's inverse Compton wavelength and the spacetime
gravitational mass) of the initial matter configuration---for generic
(non-time-symmetric) initial data to collapse to a black hole. This analytical
condition can then be used to place constraints on the initial primordial black
hole spectrum, by considering spherical density perturbations that re-entered
the horizon during an early matter-dominated phase that immediately followed
inflation.Comment: 9 pages, RevTeX, 3 eps figures; to appear in Phys. Rev.
Nonlinear Boundary Value Problems via Minimization on Orlicz-Sobolev Spaces
We develop arguments on convexity and minimization of energy functionals on
Orlicz-Sobolev spaces to investigate existence of solution to the equation
\displaystyle -\mbox{div} (\phi(|\nabla u|) \nabla u) = f(x,u) + h \mbox{in}
\Omega under Dirichlet boundary conditions, where
is a bounded smooth domain, is a
suitable continuous function and
satisfies the Carath\'eodory conditions, while is a measure.Comment: 14 page
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