14 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
Prediction of new sp3 silicon and germanium allotropes from the topology-based multiscale method
This article continues our recent publication [I.A. Baburin and D.M.
Proserpio and V.A. Saleev and A.V. Shipilova, Phys. Chem. Chem. Phys.17, 1332
(2015)] where we have presented a comprehensive computational study of sp3
carbon allotropes based on the topologies proposed for zeolites. Here we
predict six new silicon and six new germanium allotropes which have the same
space group symmetries and topologies as those predicted earlier for the carbon
allotropes, and study their structural, elastic, vibrational, electronic and
optical properties.Comment: 16 pages, 16 figures, 5 tables, supplementary fil
New mechanisms for double charmed meson production at the LHCb
We discuss production of (and ) pairs
related to the LHCb Collaboration results for = 7 TeV in
proton-proton scattering. We consider double-parton scattering (DPS) mechanisms
of double production and subsequent
hadronization as well as double and mixed production with and hadronization calculated with the help
of the scale-dependent hadronization functions of Kniehl et al. Single-parton
scattering (SPS) mechanism of digluon production is also taken into account. We
compare our results with several correlation observables in azimuthal angle
between mesons or in dimeson invariant mass
. The inclusion of new mechanisms with
fragmentation leads to larger cross sections, than when including only DPS
mechanism with standard scale-independent fragmentation
functions. Some consequences of the presence of the new mechanisms are
discussed. In particular a larger is needed to describe the LHCb
data. There is a signature that may depend on transverse
momentum of quarks and/or antiquarks.Comment: 16 pages, 6 figure
B-meson production in the Parton Reggeization Approach at Tevatron and the LHC
We study the inclusive hadroproduction of , , and mesons at
leading order in the parton Reggeization approach using the universal
fragmentation functions extracted from the combined annihilation data
from CERN LEP1 and SLAC SLC colliders. We have described -meson transverse
momentum distributions measured in the central region of rapidity by the CDF
Collaboration at Fermilab Tevatron and CMS Collaboration at LHC within
uncertainties and without free parameters, applying Kimber-Martin-Ryskin
unintegrated gluon distribution function in a proton. The forward -meson
production () measured by the LHCb Collaboration also has been
studied and expected disagreement between our theoretical predictions and data
has been obtained.Comment: 17 pages, 11 figures. arXiv admin note: substantial text overlap with
arXiv:1410.713
Heavy quark production at the LHC in the Parton Reggeization Approach
We present the general introduction to the Parton Reggeization Approach and discuss some new results on large- production for heavy quarks at the LHC. We concentrate here on study of different correlation spectra for jet pairs, meson pairs and meson pairs
Щастя як філософсько-етична категорія: трансформація розуміння від давнини до сучасності
Шипілова, О. Е. Щастя як філософсько-етична категорія: трансформація розуміння від давнини до сучасності = Happiness as a philosophical and ethical category: the transformation of understanding from antiquity to the present times / О. Е. Шипілова, О. О. Гончарова // Матеріали ІІІ всеукр. студ. наук.-практ. конф. "Філософські та культурологічні проблеми людства очима студентства. – Миколаїв : НУК, 2020. – С. 88–92.У даній статті розглянуто філософське поняття «щастя», його визначення, та розуміння у різні епохи людства. Евдемонізм постає як сенс життя у філософії. З’ясовано становлення та розвиток категорії щастя від давнини до сьогодення.This article examines the philosophical concept of happiness, its definition. The concept of happiness and its understanding in different epochs of humanity are analyzed. Eudemonism is observed as the meaning of life in Philosophy. The process of gaining happiness from Antiquity to the present times is discovered.В этой статье рассмотрены философское понятие счастья, его определение. Проанализировано понятие «счастье» и его понимание в разные эпохи развития человечества. Эвдемонизм рассматривается как смысл жизни в философии. Прослеживается становление категории счастья от древности до современности