Hybrid phenomenology in a chiral approach

We calculate masses and decays of the (lightest) hybrid nonet with exotic quantum numbers J(PC) = 1(-+) and the nonet of their chiral partners with J(PC) = 1(+-) in the framework of the extended Linear Sigma Model (eLSM). As an input, we identify pi(hyb)(1) = pi(1)(1600) as a low-lying hybrid. We investigated interaction terms which fulfill chiral symmetry. For what concerns pi(hyb)(1), the most important decays are pi(hyb)(1) -> b(1)pi, pi(1)(1600) -> rho pi eta, pi(hyb)(1) -> rho pi, and pi(hyb)(1) -> KK(892). The decays pi(hyb)(1) -> eta pi and pi(hyb)(1) -> eta 'pi are expected to be small but nonzero: they follow from a chirally symmetric interaction term that breaks explicitly the axial anomaly. For all the other members of the two hybrid nonets (for which no experimental candidates exist yet), we report decay ratios that may guide ongoing and future experiments.