Energies and radial distributions of B_s mesons on the lattice

Abstract

This is a follow-up to our earlier work for the energies and the charge (vector) and matter (scalar) distributions for S-wave states in a heavy-light meson, where the heavy quark is static and the light quark has a mass about that of the strange quark. We now study excited states of these mesons with higher angular momentum and with radial nodes. The calculation is carried out with dynamical fermions on a 16^3 times 32 lattice with a lattice spacing approximately 0.10 fm. The lattice configurations were generated by the UKQCD Collaboration. Attempts are now being made to understand these results in terms of the Dirac equation. In nature the closest equivalent of this heavy-light system is the B_s meson, which allows us to compare our lattice calculations to experimental results (where available) or give a prediction where the P-wave states should lie. We pay particular attention to the spin-orbit splitting, to see which one of the states (for a given angular momentum L) has the lower energy.