A Comment on the Extractions of V_{ub} from Radiative Decays

Preprint
Publisher Website
Google Scholar
Abstract
We present a model independent closed form expression for |V_{ub}|^2/|V_{tb} V_{ts}^*|^2, which includes the resummation of large endpoint logarithms as well as the interference effects from the operators O_2 and O_8. We demonstrate that the method to extract |V_{ub}| presented by the authors in hep-ph/9909404, and modified in this letter to include interference effects, is not just a refinement of the method described by Neubert in hep-ph/9312311. Indeed, we show that Neubert's proposal is incorrect at order alpha_s. We also point out that, contrary to what was recently claimed by Neubert in hep-ph/0104280, when the present experimental cut is used, the resummation is not negligible and that the Landau pole does not introduce any significant uncertainties.

This publication has 0 references indexed in Scilit: