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Title: Measurement of the B to pi l nu Branching Fraction and Determination of |Vub| with Tagged B Mesons

Journal Article · · Submitted to Physical Review Letters

We report a measurement of the B {yields} {pi}{ell}{nu} branching fraction based on 211 fb{sup -1} of data collected with the BABAR detector. We use samples of B{sup 0} and B{sup +} mesons tagged by a second B meson reconstructed in a semileptonic or hadronic decay, and combine the results assuming isospin symmetry to obtain {Beta}(B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}) = (1.33 {+-} 0.17{sub stat} {+-} 0.11{sub syst}) x 10{sup -4}. We determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub ub}| by combining the partial branching fractions measured in ranges of the momentum transfer squared and theoretical calculations of the form factor. Using a recent lattice QCD calculation, we find |{sub ub}| = (4.5 {+-} 0.5{sub stat} {+-} 0.3{sub syst} {sub -0.5}{sup +0.7}FF) x 10{sup -3}, where the last error is due to the normalization of the form factor.

Research Organization:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC02-76SF00515
OSTI ID:
890240
Report Number(s):
SLAC-PUB-11966; hep-ex/0607089; TRN: US0604784
Journal Information:
Submitted to Physical Review Letters, Journal Name: Submitted to Physical Review Letters
Country of Publication:
United States
Language:
English