43 research outputs found
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: . The double counting with the LO
contribution 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
-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