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Abdulla Rakhimov

Publications and source records attributed to Abdulla Rakhimov.

21 records · Page 2Linked to original sources

Stability of the homogeneous Bose-Einstein condensate at large gas parameter

The properties of the uniform Bose gas is studied within the optimized variational perturbation theory (Gaussian approximation) in a self-consistent way. It is shown that the atomic BEC with a repulsive interaction becomes unstable when the gas parameter gamma=rho a^3 exceeds a critical value gamma_{crit} ~ 0.01. The quantum corrections beyond the Bogoliubov-Popov approximation to the energy density, chemical potential and pressure in powers of gamma expansions are presented.

cond-mat.stat-mech↗

Properties of mesons and nucleons in chiral topological models of QCD

The problem under consideration in this thesis has, actually, two aspects. The first one concerns the case when a nucleon is in free space that is in vacuum, while the second one studies a nucleon embedded into a nuclear environment. Both of these two aspects have been considered in the framework of chiral topological models of QCD. The whole content of the thesis may be divided into two main parts. In the first part the original Skyrme model with finite pion mass has been extended by inclusion of the light scalar - isoscalar sigma - meson. The Lagrangian has been further extended by explicit inclusion of sigma, rho and omega - mesons as well. In order to get a more complete picture of NN potential the appropriate meson - nucleon vertex form - factors are obtained. The second part of the thesis considers a nucleon immersed into a nuclear medium. For this purpose a medium modified Skyrme Lagrangian has been proposed. The Lagrangian describes well such well known medium effects as decreasing of nucleon mass and increasing of its size (swelling). We studied also a system with finite temperature also. The temperature effects are taken into account by using the method of termofield dynamics (TFD). The corresponding critical temperatures for each meson - nucleon system are calculated .

nucl-th↗