The Exclusive Decay $B\toρe ν$ Beyond Model Calculations

Abstract

Due to its comparatively theoretical ``simplicity'', the decay channel $B\toρe ν$ offers one of the best possibilities to determine the CKM matrix element $|V_{ub}|$ accurately. I present a new calculation of the relevant hadronic form factors from light-cone sum rules. I also review the results from lattice calculations and find that they agree with the results from light-cone sum rules where comparison is possible.\\ This paper relies on work done in collaboration with V.M.\ Braun.