A Constituent Model of Light Hybrid Meson Decays

The discovery of hybrid mesons will be greatly simplified if their couplings to decay channels are understood. To this end, Christian Farina (Pitt graduate student) and Eric Swanson (Pitt, co-PI), have modeled hybrid decay in terms of gluon dissociation as specified by the Hamiltonian of QCD in Coulomb gauge. The results indicate that direct observation of the light vector hybrid will be difficult, that the hybrid $\pi(1800)$ has distinct decay characteristics, and that a hybrid $\eta_1(1750)$ should be sought. The authors argue that the isovector $π_2$ hybrid has been discovered, giving a total of four possible hybrid mesons, $\pi_1(1600)$, $\eta_1(1855)$, $\pi(1800)$, and $\pi_2(2360)$, which appear to be filling out the low lying hybrid supermultiplet in the expected fashion.

Papers: Phys. Rev. D 109 (2024), 094015