NNLO corrections to inclusive semileptonic B decays in the shape-function region
arXiv:0810.5695 · doi:10.1016/j.nuclphysb.2008.12.018
Abstract
We compute 2-loop QCD corrections to the hard coefficient functions which arise in the factorization formula for B -> X_u l nu decays in the shape-function region. Our calculation provides the last missing piece required for a NNLO analysis of inclusive semileptonic B decays, which may significantly reduce the theoretical uncertainty in the extraction of the CKM matrix element |V_ub|. Among the technical aspects, we find that the 2-loop hard coefficient functions are free of infrared singularities as predicted by the factorization framework. We perform a brief numerical analysis of the NNLO corrections and include a discussion on charm mass effects.
29 pages, 6 figures. v2: minor changes, matches published version