The lightest hybrid meson supermultiplet in QCD

Abstract

We interpret the spectrum of meson states recently obtained in non-perturbative lattice QCD calculations in terms of constituent quark-antiquark bound states and states, called `hybrids', in which the qqbar pair is supplemented by an excitation of the gluonic field. We identify a lightest supermultiplet of hybrid mesons with JPC = (0,1,2)-+, 1-- built from a gluonic excitation of chromomagnetic character coupled to qqbar in an S-wave. The next lightest hybrids are suggested to be quark orbital excitations with the same gluonic excitation, while the next distinct gluonic excitation is significantly heavier. Existing models of gluonic excitations are compared to these findings and possible phenomenological consequences explored.