302 research outputs found
Threshold pi^0 photo- and electro-production in a meson-exchange model
We show that, within a meson-exchange dynamical model describing well most of
the existing pion electromagnetic production data up to the second resonance
region, one is also able to obtain a good agreement with the pi^0 photo- and
electroproduction data near threshold. In the case of pi^0 production, the
effects of final state interaction in the threshold region are nearly saturated
by single charge exchange rescattering. This indicates that in ChPT, it might
be sufficient to carry out the calculation just up to one-loop diagrams for
threshold neutral pion production.Comment: 6 pages LATEX including 1 tables and 4 figures, uses espcrc1.st
Generalized polarizabilities and electroexcitation of the nucleon
Generalized nucleon polarizabilities for virtual photons can be defined in
terms of electroproduction cross sections as function of the 4-momentum
transfer . In particular, the sum of the generalized electric and magnetic
polarizabilities and the spin polarizability can
be expressed by virtual photon absorption cross sections integrated over the
excitation energy. These quantities have been calculated within the framework
of the recently developed unitary isobar model for pion photo- and
electroproduction on the proton, which describes the available experimental
data up to an excitation energy of about 1 GeV. Our results have been compared
to the predictions of chiral perturbation theory.Comment: 21 pages, latex, 14 figure
Cardiovascular mortality and its predictors in the republic of tatarstan (Russia)
© 2016, International Journal of Pharmacy and Technology. All rights reserved.Cardiovascular diseases remain the main cause of death in the population around the world. The US and Western European countries have tendency to reduction in cardiovascular mortality in recent decades. At the same time, in the Russian Federation, cardiovascular mortality is more than two times higher as compared to the US. Cardiovascular disease in the Russian Federation is the cause of at least 50% of all deaths. Objective: To evaluate the cardiovascular mortality in rural and urban areas of the Republic of Tatarstan of the Russian Federation during 2002-2007. To identify the predictors of cardiovascular mortality. Materials and methods: The first phase of the study was carried out in 2002. Cardiovascular diseases were diagnosed, and the risk factors were evaluated. Re-examination was conducted in 2007. The study involved total 2,353 persons. Results: cardiovascular mortality in the Republic of Tatarstan in 2002-2007 was 821.64 per 100,000 population. In the mortality structure, cardiovascular disease accounted for 66.67%. The most significant predictors of cardiovascular mortality are chronic heart failure and diabetes mellitus
Singularity structure of the pi N scattering amplitude in a meson-exchange model up to energies W < 2.0 GeV
Within the previously developed Dubna-Mainz-Taipei meson-exchange model, the
singularity structure of the pi N scattering amplitudes has been investigated.
For all partial waves up to F waves and c.m. energies up to W = 2 GeV, the
T-matrix poles have been calculated by three different techniques: analytic
continuation into the complex energy plane, speed-plot and the regularization
method. For all 4-star resonances, we find a perfect agreement between the
analytic continuation and the regularization method. We also find resonance
poles for resonances that are not so well established, but in these cases the
pole positions and residues obtained by analytic continuation can substantially
differ from the results predicted by the speed-plot and regularization methods.Comment: 21 pages, 4 figures, 4 table
Singularity structure of the pi N scattering amplitude in a meson-exchange model up to energies W < 2.0 GeV
Within the previously developed Dubna-Mainz-Taipei meson-exchange model, the
singularity structure of the pi N scattering amplitudes has been investigated.
For all partial waves up to F waves and c.m. energies up to W = 2 GeV, the
T-matrix poles have been calculated by three different techniques: analytic
continuation into the complex energy plane, speed-plot and the regularization
method. For all 4-star resonances, we find a perfect agreement between the
analytic continuation and the regularization method. We also find resonance
poles for resonances that are not so well established, but in these cases the
pole positions and residues obtained by analytic continuation can substantially
differ from the results predicted by the speed-plot and regularization methods.Comment: 21 pages, 4 figures, 4 table
Elastic Pion Scattering on the Deuteron in a Multiple Scattering Model
Pion elastic scattering on deuterium is studied in the KMT multiple
scattering approach developed in momentum space. Using a Paris wave function
and the same methods and approximations as commonly used in pion scattering on
heavier nuclei excellent agreement with differential cross section data is
obtained for a wide range of pion energies. Only for MeV and very
backward angles, discrepancies appear that are reminiscent of disagreements in
pion scattering on He, H, and He. At low energies the second order
corrections have been included. Polarization observables are studied in detail.
While tensor analyzing powers are well reproduced, vector analyzing powers
exhibit dramatic discrepancies.Comment: 25 pages LATEX and 9 postscript figures in a self-extracting uufile
archiv
Experimental study of the influence of pulse electrophoresis of blood plasma 0 (I) on healing of wounds and formation of normotrophic scars in laboratory animals
In experimental study confirmed the acceleration of wound healing and forming normotrophic scars tissue in laboratory animals using the transdermal administration of blood plasma 0 (I) by pulsed electrophoresis under the influence of an external magnetic field. It was established that the method proposed by the authors prevents the development of hypertrophic and keloid scars, and also stimulates tissue regeneration in the surgical area due to the activation of local regeneration processes
Measurement of the LT-asymmetry in \pi^0 electroproduction at the energy of the \Delta (1232) resonance
The reaction p(e,e'p)pi^0 has been studied at Q^2=0.2 (GeV/c)^2 in the region
of W=1232 MeV. From measurements left and right of q, cross section asymmetries
\rho_LT have been obtained in forward kinematics \rho_LT(\theta_\pi^0=20deg) =
(-11.68 +/- 2.36_stat +/- 2.36_sys)$ and backward kinematics
\rho_LT(\theta_\pi^0=160deg) =(12.18 +/- 0.27_stat +/- 0.82_sys). Multipole
ratios \Re(S_1+^* M_1+)/|M_1+|^2 and \Re(S_0+^* M_1+)/|M_1+|^2 were determined
in the framework of the MAID2003 model. The results are in agreement with older
data. The unusally strong negative \Re(S_0+^* M_1+)/|M_1+|^2 required to bring
also the result of Kalleicher et al. in accordance with the rest of the data is
almost excluded.Comment: 7 pages, 7 figures, 4 tables. Changed content. Accepted for
publication in EPJ
Temperature dependent fluorescence in disordered Frenkel chains: interplay of equilibration and local band-edge level structure
We model the optical dynamics in linear Frenkel exciton systems governed by
scattering on static disorder and lattice vibrations, and calculate the
temperature dependent fluorescence spectrum and lifetime. The fluorescence
Stokes shift shows a nonmonotonic behavior with temperature, which derives from
the interplay of the local band-edge level structure and thermal equilibration.
The model yields excellent fits to experiments performed on linear dye
aggregates.Comment: 4 pages, 3 figure
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