Seminar: QCD Bound States within a Truncated Dyson-Schwinger-Bethe-Salpeter Approach
Title: QCD bound states within a truncated Dyson-Schwinger-Bethe-Salpeter approach: mesons and glueballs
Speaker: Prof. Leonid KAPTAR (Bogoliubov Laboratory of Theoretical Physics, JINR)
Time: 15:00pm, Dec.5 (Thursday), 2019
Place: Room1006, Building 5
An approach based on truncated Dyson-Schwinger-Bethe-Salpeter equations within the rainbow approximation is suggested to analyze the quark, gluon and ghost propagators. The effective parameters are adjusted to experimental or to lattice data. The analytic structure of propagators in Landau gauge is analyzed as well. It is shown that the propagators entering the Bethe-Salpeter equation in complex Euclidean space are singular, with singularities as isolated pairwise conjugated poles. Albeit these poles hamper solving numerically the Bethe-Salpeter equation, researchers argue that, by knowing the position of the poles and their residues, a reliable algorithm for numerical solving the Bethe-Salpeter equation can be established. A generalization of the Dyson-Schwinger and Bethe-Salpeter equations to the case of finite temperatures will be discussed. With numerical solutions of the temperature Dyson-Schwinger and Bethe-Salpeter equations, an analysis of possible phase and/or cross-over transitions and for pion dissociation into free constituents will be presented.