Heavy and Heavy–Light Mesons and the Lorentz Structure of the Quark–Antiquark Interaction

Abstract

We solve a Minkowski-space integral equation, derived in the Covariant Spectator Theory, for quark–antiquark bound states describing heavy and heavy–light mesons. The equation’s kernel contains a one-gluon exchange interaction and a covariant generalization of a linear confining potential with a mixed scalar, pseudoscalar, and vector Lorentz structure, characterized by a continuous mixing parameter. We investigate to what extent the Lorentz structure of the confining kernel can be determined by fitting the mixing parameter to the meson spectrum.