10,544 research outputs found
Nuclear shadowing and prompt photons at relativistic hadron colliders
The production of prompt photons at high energies provides a direct probe of
the dynamics of the strong interactions. In particular, one expect that it
could be used to constrain the behavior of the nuclear gluon distribution in
and collisions. In this letter we investigate the influence of
nuclear effects in the production of prompt photons and estimate the transverse
momentum dependence of the nuclear ratios and at RHIC and LHC
energies. We demonstrate that the study of these observables can be useful to
determine the magnitude of the shadowing and antishadowing effects in the
nuclear gluon distribution.Comment: 4 pages, 3 figures. Version to be published in PR
Enhancement of prompt photons in ultrarelativistic proton-proton collisions from nonlinear gluon evolution at small-
In this paper we estimate the influence of nonlinear gluon evolution in the
production of prompt photons at the LHC pp collider. We assume the validity of
collinear factorization and consider the EHKQS parton distributions, which are
solutions of the GLR-MQ evolution equations and describe quite well the DESY
HERA data, as input in our calculations. We find that both single and
double photon production are enhanced for low- photons and central
rapidities, while this effect is absent for the high- photons. The
implications of this effect for the Quark-Gluon Plasma searches and for the QCD
background to Higgs are also discussed.Comment: 4 pages, 4 figures. Version to be published in Physical Review
Energy diffusion in strongly driven quantum chaotic systems
The energy evolution of a quantum chaotic system under the perturbation that
harmonically depends on time is studied for the case of large perturbation, in
which the rate of transition calculated from the Fermi golden rule exceeds the
frequency of perturbation. It is shown that the energy evolution retains its
diffusive character, with the diffusion coefficient that is asymptotically
proportional to the magnitude of perturbation and to the square root of the
density of states. The results are supported by numerical calculation. They
imply the absence of the quantum-classical correspondence for the energy
diffusion and the energy absorption in the classical limit .Comment: 12 pages, 3 figures, RevTe
Molecular dynamics study of the hydration of lanthanum(III) and europium(III) including many-body effects
Lanthanides complexes are widely used as contrast agents in magnetic resonance imaging (MRI) and are involved in many fields such as organic synthesis, catalysis, and nuclear waste management. The complexation of the ion by the solvent or an organic ligand and the resulting properties (for example the relaxivity in MRI) are mainly governed by the structure and dynamics of the coordination shells. All of the MD approachs already carried out for the lanthanide(III) hydration failed due to the lack of accurate representation of many-body effects. We present the first molecular dynamics simulation including these effects that accounts for the experimental results from a structural and dynamic (water exchange rate) point of view
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