Perturbative corrections to power suppressed effects in $$ \overline{B} $$ → X u ℓν
Bernat Capdevila (Dipartimento di Fisica & INFN, Università di Torino, Via Giuria 1, Torino, I-10125, Italy); Paolo Gambino (Dipartimento di Fisica & INFN, Università di Torino, Via Giuria 1, Torino, I-10125, Italy); Soumitra Nandi (Department of Physics, Indian Institute of Technology Guwahati, Guwahati, Assam, 781 039, India)
We compute the O(α s ) corrections to the Wilson coefficients of the dimension five operators in inclusive semileptonic B decays in the limit of a massless final quark. Our calculation agrees with reparametrization invariance and with previous results for the total width and improves the constraints on the shape functions that enter those decays.