Bc meson lifetime

We investigate the total inclusive decay rate of the (ground state) Bc meson within the framework of an operator product expansion in inverse powers of the heavy quark masses and subsequent matching onto nonrelativistic QCD. The expansion is organized as a series in the strong coupling and in powers of the heavy quark velocities in the Bc, reflecting the nonrelativistic nature of a heavy-heavy bound state. In this aspect the character of the expansion differs from the more familiar case of heavy-light mesons. The framework incorporates systematically corrections to the leading b- and c-quark decays due to binding effects, as well as contributions from weak annihilation and Pauli interference. Based on this approach we find for the Bc meson lifetime τBc=(0.4 endash 0.7) ps, the dominant mechanism being the decay of the charm constituent. copyright 1996 The American Physical Society