We report the results of a study of the exclusive charmless semileptonic decay, B-0 ->pi(-)center dot(+)nu, undertaken with approximately 227x10(6) BB pairs collected at the Upsilon(4S) resonance with the BABAR detector. The analysis uses events in which the signal B decays are reconstructed with an innovative loose neutrino reconstruction technique. We obtain partial branching fractions in 12 bins of q(2), the momentum transfer squared, from which we extract the f(+)(q(2)) form-factor shape and the total branching fraction B(B-0 ->pi(-)l(+)nu)=(1.46 +/- 0.07(stat)+/- 0.08(syst))x10(-4). Based on a recent unquenched lattice QCD calculation of the form factor in the range q(2)> 16 GeV2, we find the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-ub vertical bar to be (4.1 +/- 0.2(stat)+/- 0.2(syst)+0.6-0.4(FF))x10(-3), where the last uncertainty is due to the normalization of the form factor.

Measurement of the B-0 ->pi(-)l(+)nu form-factor shape and branching fraction, and determination of |V-ub| with a loose neutrino reconstruction technique

FERRONI, Fernando
2007-01-01

Abstract

We report the results of a study of the exclusive charmless semileptonic decay, B-0 ->pi(-)center dot(+)nu, undertaken with approximately 227x10(6) BB pairs collected at the Upsilon(4S) resonance with the BABAR detector. The analysis uses events in which the signal B decays are reconstructed with an innovative loose neutrino reconstruction technique. We obtain partial branching fractions in 12 bins of q(2), the momentum transfer squared, from which we extract the f(+)(q(2)) form-factor shape and the total branching fraction B(B-0 ->pi(-)l(+)nu)=(1.46 +/- 0.07(stat)+/- 0.08(syst))x10(-4). Based on a recent unquenched lattice QCD calculation of the form factor in the range q(2)> 16 GeV2, we find the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-ub vertical bar to be (4.1 +/- 0.2(stat)+/- 0.2(syst)+0.6-0.4(FF))x10(-3), where the last uncertainty is due to the normalization of the form factor.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12571/2660
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