Effective Theory Description of Weak Annihilation in B-> Xu l nu Decays

Abstract

The semileptonic B-> Xu l nu decays allow a pretty clean determination of the CKM matrix element |Vub|. Nevertheless, the presence of weak-annihilation effects near the end-point of the q2 spectrum introduces uncertainties in the inclusive calculation, requiring the use of non-perturbative techniques like heavy meson chiral perturbation theory and large NC limit.

Comments: 3 pages, 2 figures. To appear in the proceedings of the 7th International Conference on Hyperons, Charm And Beauty Hadrons (BEACH 2006), 2nd-8th July 2006, Lancaster, England