Two-loop QCD correction to differential semi-leptonic b --> u decays in the shape-function region
arXiv:0810.1230 · doi:10.1016/j.nuclphysb.2008.11.019
Abstract
We calculate the two-loop QCD correction to the form factors of on-shell b-quark decay to an energetic massless quark, which constitutes the last missing piece required for an O(alpha_s^2) determination of |V_ub| from inclusive semi-leptonic \bar B --> X_u l nu decays in the shape-function region.
24 pages, 4 figures. Properly MSbar-renormalized coefficient functions introduced. Matches published version