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 

Abstract:  

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.