Semileptonic width ratios among beauty hadrons

TL;DR

This paper uses heavy quark expansion in QCD to predict semileptonic width ratios among beauty hadrons, highlighting SU(3) breaking effects and specific differences in decay widths of various b-hadrons.

Contribution

It provides novel predictions for semileptonic decay width ratios among beauty hadrons using the heavy quark expansion framework.

Findings

B_s semileptonic width about 1% lower than B_d

Lambda_b semileptonic width about 3% higher than B_d

Pauli interference in Lambda_b about +10%

Abstract

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. B_s is expected to have the semileptonic width about 1% lower and Lambda_b about 3% higher when compared to Gamma_{sl}(B_d). The largest partial-rate preasymptotic effect is Pauli interference in the b-->u ell nu channel in Lambda_b, about +10%. We point out that the Omega_b semileptonic width is expected not to exceed that of B_d 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.