3,107 research outputs found
Heavy quarkonium production in the Regge limit of QCD: from Tevatron to LHC
Heavy quarkonium production in the framework of the non-relativistic quantum
chromodynamics and leading order of the parton Reggeization approach at the
Tevatron and LHC is discussed. In this note, we compare our predictions for the
bottomonium production at the LHC due to the color-singlet approximation of the
non-relativistic quantum chromodynamics with CMS and LHCb data. It is found,
that in the production of Upsilon(1S) states, the color-singlet mechanism is
dominating, whereas to describe the data for the inclusive Upsilon(2S) and
Upsilon(3S) production, the color- octet contributions should be taken into
account.Comment: 4 pages, 1 figure, Xth Quark Confinement and the Hadron Spectrum 8-12
October 2012 TUM Campus Garching, Munich, German
and hadroproduction in the parton Reggeization approach: Yield, polarization, and the role of fragmentation
The hadroproduction of the radially excited heavy-quarkonium states
and at high energies is studied in the parton
reggeization approach and the factorization formalism of nonrelativistic QCD at
lowest order in the strong-coupling constant and the relative
heavy-quark velocity . A satisfactory description of the
transverse-momentum () distributions measured by ATLAS, CMS, and LHCb at
center-of-mass energy TeV is obtained using the color-octet
long-distance matrix elements (LDMEs) extracted from CDF data at
TeV. The importance of the fragmentation mechanism and the
scale evolution of the fragmentation functions in the upper range, beyond
30 GeV, is demonstrated. The distributions measured by CDF
at TeV and by LHCb at TeV and forward rapidities
are well described using LDMEs fitted to ATLAS data at TeV.
Comparisons of polarization measurements by CDF and CMS at large values
with our predictions consolidate the familiar problem in the case,
but yield reasonable agreement in the case.Comment: 28 pages, 12 figures, minor text additions, references added, matches
journal versio
Hyperbolic carbon nanoforest for phase matching of ordinary and backward electromagnetic waves: second harmonic generation
We show that deliberately engineered dispersive metamaterial slab can enable
the co-existence and phase matching of contra-propagating ordinary fundamental
and extraordinary backward second harmonic surface electromagnetic modes.
Energy flux and phase velocity are contra-directed in the backward waves which
is the phenomenon that gives rise to unique nonlinear optical propagation
processes. We show that frequencies, phase, and group velocities, as well as
nanowaveguide losses inherent to the electromagnetic modes supported by such
metamaterial, can be tailored to maximize conversion of frequencies and to
reverse propagation direction of the generated wave. Such a possibility, which
is of paramount importance for nonlinear photonics, is proved with a numerical
model of the hyperbolic metamaterial made of carbon nanotubes standing on the
metal surface. Extraordinary properties of the backward-wave second harmonic
generation in the reflection direction and of the corresponding frequency
doubling metareflector in the THz are investigated with a focus on the pulsed
regime.Comment: 6 pages, 5 figures. arXiv admin note: text overlap with
arXiv:1602.0249
Pharmacological Correction of Neurological Disorders in Case of Multiple Sclerosis
The article analyzes the possibility of drug correction of common neurological disorders (pain, anxiety, depression, insomnia) using antidepressants under the conditions of experimental equivalent of multiple sclerosis on the background of basic drug therapy with methylprednisolone.Assessment of antidepressants antinociceptive potential identified “a range of activity” of the mentioned medicines (analgesic activity of classical amitriptyline antidepressant was accepted as conventional unit): paroxetine (0.9 c.u.), amitriptyline (1 c.u.), fluoxetine (1.11 c.u.) and trittico (1.16 c.u.).Comparative analysis of the duration of animals’ fading in the water at the forced swimming (Porsolt forced swimming test) found that the ability to weaken the level of anxiety and concern was the most significant for trittico and paroxetine groups. Immobilization time was 1.7 (p£0.05) and 1.6 (p£0.05), respectively, which was shorter than the corresponding figures of the active control group. The effect of antidepressants on latency, sleep duration when administered on a background of basic drug therapy with methylprednisolone was characterized by the following indicators: trittico (-66.5% and + 133.45%)³fluoxetine (-60.5% and + 117.79%)³paroxetine (-61.8% and + 93.59%)³amitriptyline (-52.75% and + 81.85%).Thus, trittico and paroxetine were reasonable to administer under the experimental equivalent of multiple sclerosis taking into account the basic hormonal therapy as a means of drug correction of pain, anxiety, depression and sleep disorders
Solving the difference initial-boundary value problems by the operator exponential method
We suggest a modification of the operator exponential method for the
numerical solving the difference linear initial boundary value problems. The
scheme is based on the representation of the difference operator for given
boundary conditions as the perturbation of the same operator for periodic ones.
We analyze the error, stability and efficiency of the scheme for a model
example of the one-dimensional operator of second difference
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