Optical properties of lowest-energy carbon allotropes from the first-principles calculations

We study the optical properties of lowest-energy carbon allotropes in the infrared, visible and ultra-violet ranges of light in the general gradient approximation of the density functional theory. In our calculations we used the all-electron approach as well as the pseudo-potential approximation. In the infrared range, the complex dielectric functions, infrared and Raman spectra have been calculated using CRYSTAL14 program. The electronic properties and energy-dependent dielectric functions in the visible and ultraviolet ranges have been calculated using VASP program. We have described with a good accuracy experimentally known optical properties of cubic diamond crystal. Using obtained set of relevant parameters for calculations, we have predicted optical constants, dielectric functions and Raman spectra for the lowest-energy hypothetical carbon allotropes and lonsdaleite.Comment: 11 pages, 7 tables, 5 figures, to be published in Computer Optic

Heavy quarkonium production at the LHC in the framework of NRQCD and parton Reggeization approach

Heavy quarkonium production in the framework of the nonrelativistic quantum chromodynamics and leading order of the parton Reggeization approach at the Tevatron and LHC Colliders is discussed. The new results, which are reviewed in this report, include the comparison with recent data on chi_{c1,c2} production from ATLAS Collaboration and special discussion of heavy quarkonium polarization issues in the considered framework.Comment: 5 pages, 2 figures. Talk at the Helmholtz International Summer School "Physics of Heavy Quarks and Hadrons", JINR, Dubna, July 15 - 28, 201

DIS structure functions in the NLO approximation of the Parton Reggeization Approach

The main ideas of the NLO calculations in Parton Reggeization Approach are illustrated on the example of the simplest NLO subprocess, which contributes to DIS: $\gamma^\star+R\to q + \bar{q}$. The double counting with the LO contribution $\gamma^\star + Q \to q$ is resolved. The problem of matching of the NLO results for single-scale observables in the Parton Reggeization Approach on the corresponding NLO results in the Collinear Parton Model is considered. In the developed framework, the usual NLO PDFs in the $\overline{MS}$-scheme can be consistently used as the collinear input for the NLO calculation in the Parton Reggeization Approach.Comment: 10 pages, 2 figures, Talk at the QFTHEP-2017, June, 2017, Yaroslavl, Russi