A Constituent Model of Light Hybrid Meson Decays

Abstract: A model of light hybrid mesons and their strong decays is developed. The model employs a gluonic quasiparticle to describe low energy gluodynamics and uses the QCD Hamiltonian in Coulomb gauge to guide the construction of states and decay amplitudes. We compute the partial widths of the twelve low lying isovector and vector hybrids. Implications of these results on hybrid searches are also made, with the chief conclusions being that direct observation of the vector states will be difficult, that a hybrid $\pi(1800)$ has distinctive decay characteristics, a narrow $\eta(1900)$ hybrid should exist, an $\eta_1(1750)$ should be sought, and that the exotic nature of $J^{PC}= 2^{-+}$ hybrid mesons should be discernible with sufficient data. We argue that the isovector $\pi_2$ 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 lowlying hybrid supermultiplet in the expected fashion.