arXiv subjects

A. A. Shanenko

Publications and source records attributed to A. A. Shanenko.

61 records · Page 4Linked to original sources

arXiv1998

Large Bipolaron in a Polaron-Gas Background

A criterion, proposed by the present authors, is used to derive numerical results for the stability of a large bipolaron embedded in a polaron gas. The main conclusion is that an isolated metastable bipolaron can be stabilized by the polaron gas surroundings because of the Fermi statistics of polarons. On the other hand, it is found that the exchange interaction tends to destabilize the bipolaron. The study is performed both for bulk (3D) materials and for thin (2D) films within the Hartree-Fock approximation. The bipolaron is described by an extension of the Feynman

cond-mat↗

arXiv1998

A Mixed Phase Model and the 'Softest Point' Effect

Particularities of the statistical mixed phase model for describing the deconfinement phase transition and physics constraints on the model parameters, are discussed. The modifications proposed concern an improved treatment of hadron-hadron interactions within the nonlinear mean-field model of nuclear matter and an inclusion of the one-gluon exchange correction into the quark-gluon sector of the mixed phase thermodynamic potential. It is shown that the mixed phase model successfully reproduces both the available lattice data on the QCD deconfinement transition and thermodynamic characteristics of hadron systems evaluated within the modern models. The 'softest point' of the equation of state resulting in a possible formation of a long-lived fireball in nuclear collisions (the 'softest point' effect) is analyzed. The obtained results are confronted with the data on the two-phase model. Some manifestation of the mixed phase formation and deconfinement transition is estimated in fireball expansion dynamics. We discuss experimental possibilities of observing the softest point effect as a signal of the deconfinement phase transition.

nucl-th↗

arXiv1997

On the Charged Bose Liquid

A new approach developed by A. Shanenko [Phys. Lett. A 227 (1997) 367] for investigating the spatial boson correlations at low temperatures is considered in the particular case of the Coulomb interaction potential. This approach is based on integro-differential equations for the radial distribution function and can be used beyond the weak coupling regime.

cond-mat.stat-mech↗

arXiv1997

On the Momentum Distribution and Condensate Fraction in the Bose Liquid

The model recently proposed by A.A. Shanenko [Phys. Lett. A 227 (1997) 367] is used to derive linear integro-differential equations whose solutions provide reasonable estimates for the momentum distribution and condensate fraction in interacting many-boson system at zero temperature. An advantage of these equations is that they can be employed in the weak coupling regime and beyond. As an example, analytical treatment of the weak coupling case is given.

cond-mat.stat-mech↗

arXiv1996

On Pair-Particle Distribution in Imperfect Bose Gas

A simple model of estimating the radial distribution function of an imperfect Bose gas in the ground state is presented. The model is based on integro-differential equations derived by considering the space boson distribution in an external field. With the approach proposed, the particular case of dilute Bose gas is investigated within the hard sphere approximation and beyond.

cond-mat↗

arXiv1996

Particle Correlations in the Generalized Thomas-Fermi Approach

This paper presents the Thomas-Fermi approach generalized to consider the particle correlations in many-body systems with non-Coulomb interaction potentials. The key points of the generalization consist in using integral formulation and extracting the pair distribution function. The latter has been found to obey the integral equation which, in the classical limit, is reduced to the well-known equation of Bogoliubov. So, the approach presented gives the way of taking into account interactions in the quantum many-body systems beyond the weak coupling perturbation theory.

cond-mat↗

arXiv1995

Towards a New Strategy of Searching for QCD Phase Transition in Heavy Ion Collisions

We reconsider the Hung and Shuryak arguments in favour of searching for the deconfinement phase transition in heavy ion collisions {\em downward} from the nominal SPS energy, at $E_{lab} \approx 30 \ GeV/A$ where the fireball lifetime is the longest one. Using the recent lattice QCD data and the mixed phase model, we show that the deconfinement transition might occur at the bombarding energies as low as $E_{lab}=3 - 5 \ GeV/A$. Attention is drawn to the study of the mixed phase of nuclear matter in the collision energy range $E_{lab}= 2-10 \ GeV/A$.

nucl-th↗