Semileptonic width ratios among beauty hadrons

We present predictions based on the heavy quark expansion in QCD. We find SU(3) breaking in B mesons suppressed in the framework of the HQE. Bs is expected to have the semileptonic width about 1% lower and Λb about 3% higher when compared to Γsl(Bd). The largest partial-rate preasymptotic effect is Pauli interference in the b → ulν channel in Λb, about +10%. We point out that the Ωb semileptonic width is expected not to exceed that of Bd and may turn out to be the smallest among stable b hadrons despite the large mass. The underlying differences with phase-space models are briefly addressed through the heavy mass expansion.