Orbitally excited and hybrid mesons from the lattice.

We discuss in general the construction of gauge-invariant nonlocal meson operators on the lattice. We use such operators to study the {ital P}- and {ital D}-wave mesons as well as hybrid mesons in quenched QCD, with quark masses near the strange quark mass. The resulting spectra are compared with experiment for the orbital excitations. For the states produced by gluonic excitations (hybrid mesons) we find evidence of mixing for nonexotic quantum numbers. We give predictions for masses of the spin-exotic hybrid mesons with {ital J}{sup {ital PC}}=1{sup {minus}+}, 0{sup +{minus}}, and 2{sup +{minus}}. {copyright} {ital 1996 The American Physical Society.}