Measuring V_ub in Inclusive B Decays to Charm

TL;DR

This paper introduces a new method to measure the CKM matrix element V_ub through inclusive B decays to wrong sign charm, offering a theoretically clean approach with minimal uncertainties.

Contribution

It presents a novel measurement technique for V_ub using inclusive B decays to wrong sign charm, with detailed calculations including perturbative and nonperturbative corrections.

Findings

Decay rate calculation with small theoretical uncertainties

Method reduces dependence on quark mass uncertainties

No leading renormalon ambiguity in the measurement

Abstract

We propose a novel method of measuring the CKM matrix element V_ub, via inclusive B decays to "wrong sign" charm. This process is mediated by the quark level decay b -> u cbar s'. When normalized to the inclusive semileptonic decay rate, the theoretical expression is very well behaved, with small uncertainties from unknown quark masses and no leading renormalon ambiguity. We compute the decay rate for this process, including the leading perturbative and nonperturbative corrections.