Precision Determination of $|V_{ub}|$

Abstract

The last two years have seen an impressive improvement in the determination of $|V_{ub}|$, especially from inclusive decays. The error on $|V_{ub}|$ measured with inclusive decays was reduced from 18% (PDG 2004) to 8% (PDG 2006). This progress is a result of combined experimental and theoretical efforts. In this talk, the theoretical framework (BLNP) that enabled such progress is reviewed, as well as other approaches to an inclusive determination of $|V_{ub}|$ (DGE, $M_X-q^2$ etc.). The prospects of improving $|V_{ub}|$ are discussed, addressing issues of weak annihilation, implications of leptonic B decays, and determination of $|V_{ub}|$ with exclusive decays.