The charmed and bottom meson spectrum from lattice NRQCD

The mass spectrum of S and P-wave mesons containing a single heavy quark ha s been computed using quenched lattice nonrelativistic QCD. Numerical resul ts have been obtained at first, second and third order in the heavy quark e xpansion, so convergence can be discussed. The computed spectrum of charmed and bottom mesons is compared to existing model calculations and experimen tal data.