Measurement of the CKM Matrix Element |Vub| with Charmless Exclusive Semileptonic B Meson Decays at BABAR

TL;DR

This paper reports a preliminary measurement of the branching fraction and the CKM matrix element |Vub| using charmless semileptonic B meson decays at BABAR, employing multiple form-factor models to ensure robustness.

Contribution

It provides the first measurement of |Vub| from B to rho e nu decays at BABAR, incorporating five different form-factor calculations for improved accuracy.

Findings

Branching fraction BF(B0 to rho- e+ nu) = (3.39+-0.44+-0.52+-0.60)x10^(-4)

CKM matrix element |Vub| = (3.69+-0.23+-0.27+0.40-0.59)x10^(-3)

Results include statistical, systematic, and theoretical uncertainties.

Abstract

We present a preliminary measurement of the branching fraction for B to rho e nu and of the CKM matrix element |Vub| using approximately 55 million B Bbar meson pairs collected with the BABAR detector. Using isospin relations for several modes we find BF(B0 to rho- e+ nu) = (3.39+-0.44+-0.52+-0.60)x10^(-4) and |Vub| = (3.69+-0.23+-0.27+0.40-0.59)x10^(-3). The quoted errors are statistical, systematic, and theoretical, respectively. These results are obtained by using five different form-factor calculations.