  The ground state phase diagram of the half-filled repulsive Hubbard model in
a bilayer is investigated using cluster dynamical mean field theory. For weak
to intermediate values of Coulomb repulsion $U$, the system undergoes a
transition from a Mott insulating phase to a metallic phase and then onto a
band insulating phase as the interlayer hopping is increased. In the strong
coupling case, the model exhibits a direct crossover from a Mott insulating
phase to a band insulating phase. These results are robust with respect to the
presence or absence of magnetic order.
