Regge trajectories and quarkonium spectrum from a first principle Salpeter equation

Abstract

We compute the heavy-heavy, light-light and light-heavy quarkonium spectrum starting from a first principle Salpeter equation obtained in a preceding paper. We neglect spin-orbit structures and exclude from our treatment the light pseudoscalar states which are related to the chiral symmetry breaking problem. We find an overall good agreement with the experimental data and in particular straight Regge trajectories with the right slope and intercepts. The potential parameters are fixed by the heavy quarkonium fit. The light quark masses are set equal to baricentral value of the current quark masses as reported by the particle data group. For light-light and light-heavy systems the calculation is essentially parameter free.