TY - JOUR

T1 - Study of B --> pi l nu and B --> rho l nu Decays and Determination of |V_ub|

AU - del Amo Sanchez, P.

AU - Playfer, Stephen

AU - The BaBar Collaboration

AU - Clark, Philip

N1 - 47 pages, 26 postscript figures, accepted by Phys. Rev. D

PY - 2010/5/18

Y1 - 2010/5/18

N2 - We present an analysis of exclusive charmless semileptonic B-meson decays based on 377 million BBbar pairs recorded with the BABAR detector at the Upsilon(4S) resonance. We select four event samples corresponding to the decay modes B0 --> pi- l+ nu, B+ --> pi0 l+ nu, B0 --> rho- l+ nu, and B+ -> rho0 l+ nu, and find the measured branching fractions to be consistent with isospin symmetry. Assuming isospin symmetry, we combine the two B --> pi l nu samples, and similarly the two B --> rho l nu samples, and measure the branching fractions BF(B0 --> pi- l+ nu) = (1.41 +- 0.05 +- 0.07) x 10^-4 and BF(B0 --> rho- l+ nu) = (1.75 +- 0.15 +- 0.27) x 10^-4, where the errors are statistical and systematic. We compare the measured distribution in q^2, the momentum transfer squared, with predictions for the form factors from QCD calculations and determine the CKM matrix element |V_ub|. Based on the measured partial branching fraction for B --> pi l nu in the range q^2 pi l nu, where the error is the combined experimental and theoretical uncertainty.

AB - We present an analysis of exclusive charmless semileptonic B-meson decays based on 377 million BBbar pairs recorded with the BABAR detector at the Upsilon(4S) resonance. We select four event samples corresponding to the decay modes B0 --> pi- l+ nu, B+ --> pi0 l+ nu, B0 --> rho- l+ nu, and B+ -> rho0 l+ nu, and find the measured branching fractions to be consistent with isospin symmetry. Assuming isospin symmetry, we combine the two B --> pi l nu samples, and similarly the two B --> rho l nu samples, and measure the branching fractions BF(B0 --> pi- l+ nu) = (1.41 +- 0.05 +- 0.07) x 10^-4 and BF(B0 --> rho- l+ nu) = (1.75 +- 0.15 +- 0.27) x 10^-4, where the errors are statistical and systematic. We compare the measured distribution in q^2, the momentum transfer squared, with predictions for the form factors from QCD calculations and determine the CKM matrix element |V_ub|. Based on the measured partial branching fraction for B --> pi l nu in the range q^2 pi l nu, where the error is the combined experimental and theoretical uncertainty.

KW - hep-ex

UR - http://www.scopus.com/inward/record.url?scp=79952300070&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.83.032007

DO - 10.1103/PhysRevD.83.032007

M3 - Article

JO - Physical Review D, particles, fields, gravitation, and cosmology

JF - Physical Review D, particles, fields, gravitation, and cosmology

ER -