Inclusive semileptonic B decays and the determination of |V_ub|

TL;DR

This paper provides a comprehensive theoretical analysis of inclusive semileptonic B decays, incorporating higher-order effects and non-perturbative corrections to improve the extraction of the CKM matrix element |V_ub| from experimental data.

Contribution

It introduces a detailed framework including all relevant effects up to O(alphas^2 beta_0) and 1/mb^3, and applies it to extract |V_ub| with a thorough uncertainty estimate.

Findings

Consistent inclusion of perturbative and non-perturbative effects up to specified orders.

Detailed treatment of high-q^2 tail and Weak Annihilation uncertainties.

Estimated |V_ub| value with quantified theoretical errors.

Abstract

We study the triple differential distribution of B-> Xu l nu, consistently including all perturbative and non-perturbative effects through O(alphas^2 beta_0) and O(1/mb^3). The Fermi motion is parameterized in terms of a single light-cone function for each structure function and for any value of q^2, accounting for all subleading effects. We discuss the problems and uncertainties related to the high-q^2 tail and to Weak Annihilation effects. We work in the kinetic scheme, a framework characterized by a Wilsonian treatment with a hard cutoff mu ~ 1GeV. Our method is illustrated with the extraction of |V_ub| from some of the latest experimental data, providing a detailed estimate of the theoretical uncertainty.