Inclusive B decays from resummed perturbation theory.

Abstract

I review the recent progress in computing inclusive B decay widths and spectra and its implications on the interpretation of measurements from the B factories. I discuss the inclusive charmless semileptonic decay, ¯B ! Xul¯ , which provides the most robust determination of the CKM parameter |Vub|, and the rare radiative decay, ¯B ! Xs , which constrains flavor violation beyond the Standard Model. I demonstrate that precise predictions for the experimentally–relevant branching fractions can be derived from resummed perturbation theory and explain the way in which the resummation further provides guidance in parametrizing non-perturbative Fermi–motion effects. Finally I address the comparison between theory and data and discuss future prospects.