tailieunhanh - Báo cáo "Quantum kinetic equation in the quantum hadrondynamics (QHD-I) model "

Within the framework of the Walecka model (QHD-I)[1] the renormalized effective Dirac equation and the kinetic equation for fermion are presented. In fact, the fermion propagator in the medium is dramatically different from that in the vacuum. The main feature is the treating of the fermion distribution in non equilibrium, which depends on the interaction rate involving temperature. | VNU Journal of Science Mathematics - Physics 24 2008 145-154 Quantum kinetic equation in the quantum hadrondynamics QHD-I model Phan Hong Lien 100 Hoang Quoc Viet Street Hanoi Vietnam Received 8 August 2008 received in revised form 30 August 2008 Abstract. Within the framework of the Walecka model QHD-I 1 the renormalized effective Dirac equation and the kinetic equation for fermion are presented. In fact the fermion propagator in the medium is dramatically different from that in the vacuum. The main feature is the treating of the fermion distribution in non equilibrium which depends on the interaction rate involving temperature. Keyworks field Theory nuclear Theory. 1. Introduction At present the theoretical study of quantum fields at finite temperature and density turns out to be more and more important for description of wide variety of physical effects in medium in condensed matter 2 3 in stellar astrophysics 3 4 in a QED or QCD plasma 5 6 . The effective real-time Dirac equation in medium and the kinetic equation not only may provide an approximation beyond two-loop calculations but also can be treated the correlation effects- those that are extremely important for physical processes near equilibrium 8 . In this paper we focus on the QHD-I model of non-zero density. We investigate in detail the fermion propagator and its relaxation and thermalization through the interaction with scalar and neutral vector mesons in the matter. Furthermore the kinetic equation for fermion in the real time is shown the relation between the fermion distribution and the interaction rate. The paper is organized as follows. In Sec. II the QHD-I and the real time formalism are presented. Sec. III is devoted to considering the renormalized effective Dirac equation. In Sec. IV we carry out the quantum kinetic equation for fermion in the QHD-I. The discussion and conclusion are given in Sec. V. Tel. 84-4 38230469 E-mail pnhue2000@ 145 146 . Lien VNU Journal of Science .