New predictions for the lifetimes of doubly heavy baryons and the Bc meson

A bstract We present updated predictions for the lifetimes of all weakly decaying doubly heavy baryons, including bb , cc , and bc baryons, as well as for the B c meson. The analysis includes NNLO corrections to the leading dimension-three contribution, NLO corrections to the chromomagnetic term, and the complete set of currently known NLO corrections to the dimension-six heavy-light quark spectator contributions, including penguin terms. We also compare the results in the $$\overline{\text{M}\text{S} }$$ , kinetic, and, where applicable, Υ mass schemes. For the bc baryons, we present predictions for both possible ground-state diquark-spin assignments, S bc = 0 and S bc = 1. In the kinetic scheme we obtain the lifetime hierarchies $$\tau \left({\Xi}_{bb}^{0}\right) for S bc = 0, and $$\tau \left({\Xi}_{bc}^{{\prime}0}\right) for S bc = 1. We also revisit the B c lifetime and discuss the impact of the newly included Darwin term.