Measurement of the Branching Fraction for Inclusive Semileptonic B Meson Decays

TL;DR

This paper presents a largely model-independent measurement of the inclusive semileptonic B meson decay branching fraction and electron spectrum, using data from the BABAR detector at the Upsilon(4S) resonance, and derives the CKM matrix element |V_cb|.

Contribution

It provides a new, largely model-independent measurement of the inclusive B meson semileptonic decay branching fraction and electron spectrum, improving precision in |V_cb| determination.

Findings

Branching fraction BR(B -> X e nu) = (10.87 +-0.18(stat)+-0.30(syst))%

Separation of secondary charm decay backgrounds from prompt B decays

Determination of the CKM matrix element |V_cb|

Abstract

A largely model-independent measurement of the inclusive electron momentum spectrum and branching fraction for semileptonic decays of B mesons is presented based on data recorded at the Upsilon(4S) resonance with the BABAR detector. Backgrounds from secondary charm decays are separated from prompt B decays using charge and angular correlations between the electron from one B meson and a high momentum electron tag from the second B meson. The resulting branching fraction is BR(B -> X e nu) = (10.87 +-0.18(stat)+-0.30(syst))%. Based on this measurement we determine the CKM matrix element |V_cb|.