Photon plus heavy quark production in high energy collisions within the target rest frame formalism

We apply the target rest frame formalism to photon + heavy quark production cross section in hadronic collisions at high energies. We investigate the dependence of the production cross section on the photon and quark rapidities and transverse momenta. It is shown that the photon transverse momentum spectrum is a sensitive probe of color dipole scattering amplitude. The theoretical results are compared to Tevatron measurements of the differential \gamma + c + X and \gamma + b + X production cross sections at 1.96 TeV. An analysis for proton-proton and proton-lead collisions at the LHC regime is also performed.Comment: 6 pages, 3 figures. Version to be published in Physical Review

Parton saturation effects to the Drell-Yan process in the color dipole picture

We report on the results obtained in the study of the parton saturation effects, taken into account through the multiscattering Glauber-Mueller approach, applied to the Drell-Yan (DY) process described in the color dipole picture. As a main result, one shows that those effects play an important role in the estimates of the DY differential cross section atRHIC energies.Comment: To appear in the proceedings of the VIII International Workshop on Hadron Physics 200

Charm and bottom production in inclusive double Pomeron exchange in heavy ion collisions at the LHC

The inclusive double Pomeron exchange cross section for heavy quark pair production is calculated for nucleus-nucleus collisions at the LHC. The present estimate is based on hard diffractive factorization, corrected by absorptive corrections and nuclear effects. The theoretical uncertainties for nuclear collisions are investigated and a comparison to other approaches is presented. The production channels producing a similar final state configuration are discussed as well.Comment: 7 pages, 3 tables. Final version to be published in Physical Review

Studies of the photoionization cross sections of CH_4

We present cross sections and asymmetry parameters for photoionization of the 1t_2 orbital of CH_4 using static‐exchange continuum orbitals of CH^+_4 to represent the photoelectron wave function. The calculations are done in the fixed‐nuclei approximation at a single internuclear geometry. To approximate the near‐threshold behavior of these cross sections, we assumed that the photoelectron spectrum is a composite of three electronic bands associated with the Jahn–Teller components of the distorted ion. The resulting cross sections reproduce the sharp rise seen at threshold in the experimental data and are in good agreement with experiment at higher energy. The agreement between the calculated and measured photoelectron asymmetry parameters is, however, less satisfactory

Preparation of polymer-based nanocomposites by different routes

Since the eighties, polymeric nanocomposites have been intensely investigated due to the performance improvement achieved when a small amount of nanosized particles are added to a polymer matrix. The remarkable changes on physical and mechanical properties of polymers due to the addition of inorganic solid nanoparticles (typically in form of fibres, flakes, spheres or fine particles) is explained by the huge surface area, which increases the interaction between the nanoparticle and the polymer. Moreover, nanocomposites can be produced using conventional polymer processing techniques, which makes them particularly interesting from the production point of view. Therefore, this chapter will make an overview about different routes to prepare polymer-based nanocomposites by extrusion, mainly synthesis of nanoparticles by sol-gel reactions and dispersion of clays in polymer matrices