394 research outputs found
Near-threshold production of -mesons in and NN collisions and -mixing
We consider near-threshold -meson production in and
collisions. An effective Lagrangian approach with one-pion exchange is applied
to analyze different contributions to the cross section for different isospin
channels. The Reggeon exchange mechanism is also evaluated for comparison. The
results from reactions are used to calculate the contribution of the
meson to the cross sections and invariant mass distributions
of the reactions and . It is found that
the experimental observation of mesons in the reaction is much more promising than the observation of mesons in
the reaction . Effects of isospin violation in the reactions
, , and , which are induced by -- mixing, are also analyzed.Comment: 43 pages, including 16 eps figures, to be bublished in Phys. Atom.
Nucl. (Yad. Fiz.) vol. 65, No. 11 (2002
The K^- \alpha scattering length and the reaction dd \to \alpha K^+ K^-
We present predictions for the the K^- \alpha scattering length obtained
within the framework of the multiple scattering approach. Evaluating the pole
position of the K^- \alpha scattering amplitude within the zero range
approximation, we find a loosely bound K^- \alpha state with a binding energy
of E_R = -2 ... -7 MeV and a width \Gamma_R = 11 ... 18 MeV. We propose to
measure the K^- \alpha scattering length through the final state interaction
between the \alpha and K^- meson produced in the reaction dd \to \alpha K^+
K^-. It is found that the K^-\alpha invariant mass distribution from this
reaction at energies near the threshold provides a new tool to determine the
s-wave K^- \alpha scattering length.Comment: 6 pages, 3 PS figure
Aspects of a0-f0 mixing in the reaction pn->da0
Some aspects of a0-f0 mixing effects in the reaction
with perpendicular polarized proton beam are discussed. An angular--asymmetry
parameter is defined to study those effects. It is shown that, for energies
close to the production threshold, the angular--asymmetry parameter is proportional to the a0-f0 mixing amplitude for arbitrary polar and
azimuthal angles and of the outgoing meson. This
statement is also valid for arbitrary energies, but then only at polar angles
and . The mass dependence of the differential cross
section in the reaction in the
presence of \mix mixing is also discussed.Comment: 17 pages, 3 Figure
Special approach to the analysis and evaluation of the composition of red blood in athletes (on the example of rowing and canoeing)
The results of the analysis of red blood parameters in professional rowers showed that they have different mechanisms for the development of pre- and anemic conditions. This makes it necessary in each specific case to determine the prevailing of them, which requires an expansion of the set of recorded parameters
Approaches to the classification of sports disciplines, taking into account their influence on the biochemical profile of an athlete
There are many classifications of sports disciplines, which base on various approaches, which separately take into account the patterns of training activity, physiology, the risk of collision and injury, etc. In our opinion, it most fully reflects the specifics of sports changes that occur in the body of athletes under the influence of intense physical activity, at the level of biochemical processes. The classification of sports disciplines proposed by us takes into account the influence of the nature of the training process, the specifics of sports loads, the leading type of energy supply of sports work on the biochemical profile of an athlete, which makes it possible to identify the key features that occur in the body of an athlete under the influence of a specific load
Indication of asymptotic scaling in the reactions H, He and
It is shown that the differential cross sections of the reactions and measured at c.m.s.scattering angle
in the interval of the deuteron beam energy 0.5 - 1.2 GeV demonstrate the
scaling behaviour,, which follows from constituent
quark counting rules. It is found also that the differential cross section of
the elastic scattering at follows
the scaling regime at beam energies 0.5 - 5 GeV. These data are
parameterized here using the Reggeon exchange.Comment: 6 pages, Latex, 2 eps figures; final version accepted by Pis'ma v
ZHETF, corrected and completed reference
Production of -mesons in pp and pn reactions
We investigate the cross section for the reaction near
threshold and at medium energies. An effective Lagrangian approach with
one-pion exchange is applied to analyze different contributions to the cross
section for different isospin channels. The Reggeon exchange mechanism is also
considered. The results are used to calculate the contribution of the
meson to the cross sections and invariant mass distributions of the
reactions and . It is found that the
experimental observation of mesons in the reaction is much more promising than the observation of mesons in the
reaction .Comment: 26 pages, including 11 eps figures, to be bublished in J. Phys.
Laboratory Diagnostics of Coccidioidomycosis
Coccidioidomycosis is a systemic disease induced by dimorphic fungi Coccidioides and C. posadasii. Its causative agents - primary pathogens - are endemic for American states. However introduced cases of the disease can be traced in some other world regions too. This paper contains summarized foreign literature data on the issue. Presented are the results of our own investigations on the problem of Coccidioidomycosis diagnostics. Discussed are also problems and prospective of the development of a diagnostic preparations designed to detect and identify Coccidioides spp
Neurotrophic and antioxidant potential of neuropeptides and trace elements
Neurotrophic therapy with brain extract-based drugs has been performed for decades. The basis for their neurotrophic activity is amino acids and neuropeptides. However, incomplete information on the composition of these drugs precludes a detailed description of mechanisms through which their pharmacological effects occur. The review considers the results of the most recent molecular pharmacological investigations and the mechanisms of therapeutic action of cerebrolysin
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