PSEUDOSCALAR DECAY CONSTANTS AND MASS SPECTRUM OF $q\bar q$ AND $Q\bar q$ SYSTEM IN QCD THEORY INVOLVING THE VACUUM CONDENSATES

Abstract

We present the results of a study of light-light and heavy-light quark bound states by solving the Bethe-Salpeter equation, in which the non-perturbative part of the kernel is calculated up to four dimensions vacuum condensates in QCD in the background fields. We believe that it is a good approximation to neglect higher dimension vacuum condensates since we only deal with the ground states for 0− mesons. Indeed, satisfactory results (spectrum and decay constants) are obtained with reasonable parameters. In particular, we get an approximate relation [Formula: see text] for the heavy-light quark mesons numerically.