Prompt charmonia production and polarization at LHC in the NRQCD with kt-factorization. Part I: psi(2S) meson

In the framework of kt-factorization approach, the production and polarization of prompt psi(2S) mesons in pp collisions at the LHC energies is studied. Our consideration is based on the non-relativistic QCD formalism for bound states and off-shell amplitudes for hard partonic subprocesses. The transverse momentum dependent (unintegrated) gluon densities in a proton were derived from Ciafaloni-Catani-Fiorani-Marchesini evolution equation or, alternatively, were chosen in accordance with Kimber-Martin-Ryskin prescription. The non-perturbative color-octet matrix elements were first deduced from the fits to the latest CMS data on psi(2S) transverse momentum distributions and then applied to describe the ATLAS and LHCb data on psi(2S) production and polarization at 7 TeV. We perform the estimation of polarization parameters $\lambda_\theta$, $\lambda_\phi$ and $\lambda_{\theta \phi}$ which determine psi(2S) spin density matrix and demonstrate that taking into account the off-shellness of initial gluons in the color-octet contributions leads to unpolarized psi(2S) production at high transverse momenta, that is in qualitative agreement with the LHC data.Comment: 19 pages, 8 figures. arXiv admin note: text overlap with arXiv:1108.285

TMD PDFs in Drell-Yan lepton pair production at LHC

We consider the transverse momentum dependent (TMD) quark densities of the proton which are very important ingredients for unpolarized Drell-Yan (DY) lepton pair production. We calculate the TMD sea quark density as a convolution of the Catani-Ciafaloni-Fiorani-Marchesini (CCFM)-evolved gluon distribution and the TMD gluon-to-quark splitting function. Based on the ${\cal O}(\alpha^2)$ production amplitude $q^* + \bar q^* \to Z/\gamma^* \to l^+ + l^-$, calculated by taking into account the effective $q^*\bar q^* Z/\gamma^*$ - vertex, we analyze the distributions on the dilepton invariant mass, transverse momentum and rapidity and specific angular correlations between the produced leptons as measured by the CMS, ATLAS and LHCb collaborations. We briefly duscuss also the process of assiciated lepton pair and jet production in $pp$ collisions at the LHC.Comment: Talk presented at International Workshop on Diffraction in High-Energy Physics, Diffraction-201

Heavy Quark Production in the Semihard QCD Approach at HERA and Beyond

Processes of heavy quark production at HERA, TEVATRON and THERA energies are considered using the semihard ($k_T$ factorization) QCD approach with emphasis on the BFKL dynamics of gluon distributions.Comment: 4 pages, 5 figures, To appear in Proceedings of the 9th International Workshop on Deep Inelastic Scattering (DIS2001), Bologna, Italy, 27 Apr. - 1 May 200

Specific features of the charge and mass transfer in a silver-intercalated hafnium diselenide

The specific features of the charge transfer in intercalated samples of AgxHfSe2 have been studied for the first time by alternating current (ac) impedance spectroscopy. It has been found that relaxation processes in an ac field are accelerated with increasing silver content in the samples. The complex conductivity (Y) shows a frequency dispersion described by power law Y ∼ ωs, which is characteristic of the hopping conductivity mechanism. The AgxHfSe2 compounds demonstrate shorter relaxation times as compared to those observed in hafnium diselenide intercalated with copper atoms, and this fact indicates that the charge carrier mobility in the silver-intercalated compounds is higher. The possibility of silver ion transfer in AgxHfSe2 is confirmed by the measurements performed by the method of electrochemical cell emf. © 2013 Pleiades Publishing, Ltd

Transport properties and polarization phenomena in intercalated AgxHfSe2 compounds

The electrical properties of intercalated AgxHfSe2 compounds (x = 0. 1, 0. 2) have been investigated for the first time. Investigations have been performed using various current electrodes, which make it possible to pass either the electron current or the ion current across the sample. Polarization effects, which indicate the self-consistent migration of charge carriers in the samples, have been found for the samples at room temperature. Based on the characteristic features of polarization decay, coefficients of conjugated chemical diffusion have been evaluated. © 2013 Pleiades Publishing, Ltd