Excited B mesons from the lattice

We determine the energies of the excited states of a heavy-light meson Q¯ q, with a static heavy quark and light quark with mass approximately that of the strange quark from both quenched lattices and with dynamical fermions. We are able to explore the energies of orbital excitations up to L=3, the spin-orbit splitting up to L=2 and the first radial excitation. These b¯ s mesons will be very narrow if their mass is less than 5775 MeV — the BK threshold. We investigate this in detail and present evidence that the scalar meson (L=1) will be very narrow and that as many as 6 b¯ s excited states will have energies close to the BK threshold and should also be relatively narrow.