QCD Calculations of Decays of Heavy Flavor Hadrons

TL;DR

This paper reviews theoretical techniques for calculating decay rates of heavy flavor hadrons, focusing on processes like B->Xs+gamma and extracting CKM matrix elements, crucial for testing the Standard Model.

Contribution

It provides an overview of recent developments in QCD calculations for heavy flavor decays, including new methods for determining |V(ub)| and the b-quark mass.

Findings

Updated |V(ub)| value: (3.98+-0.15+-0.30)×10^{-3}

|V(ub)| from clean channels: (3.70+-0.15+-0.28)×10^{-3}

Enhanced theoretical techniques for decay rate calculations.

Abstract

Precision tests of the Standard Model and searches for New Physics in the quark flavor sector depend on accurate theoretical calculations of decay rates and spectra for rare, flavor-changing processes. The theoretical status and recent developments of techniques allowing such calculations are reviewed. Special attention is paid to the calculation of the B->Xs+gamma branching ratio, the extraction of the b-quark mass from a fit to B->Xc+l+nu moments, and the determination of |V(ub)| from spectra in the inclusive decay B->Xu+l+nu. From a reanalysis of different inclusive distributions the updated average value |V(ub)|=(3.98+-0.15+-0.30)*10^{-3} is derived. Using only the theoretically cleanest channels, we obtain |V(ub)|=(3.70+-0.15+-0.28)*10^{-3}.