Exotic hybrid mesons and four-quark states

Abstract

We calculate masses of mesons with exotic quantum numbers in the quenched approximation. Using a four quark source operator, we demonstrate mixing of the 1 −+ meson with four-quark states. Using the conventional Wilson quark action, we calculate both at reasonably light quark masses, intending to extrapolate to small quark mass, and near the charmed quark mass, where we calculate the masses of some ccg hybrid mesons. The hybrid masses are large — over 4 GeV for charmonium and more than twice the vector meson mass at the strange quark mass.