We present an analysis of exclusive charmless semileptonic B-meson decays based on 83×10^6 BB̅ pairs recorded with the BABAR detector at the Υ(4S) resonance. Using isospin symmetry, we measure branching fractions B(B0→π-ℓ+ν)=(1.38±0.10±0.16±0.08)×10-4 and B(B0→ρ-ℓ+ν)=(2.14±0.21±0.48±0.28)×10-4, where the errors are statistical, experimental systematic, and due to form-factor shape uncertainties. We compare the measured distribution in q2, the momentum-transfer squared, with theoretical predictions for the form factors from lattice QCD and light-cone sum rules, and extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |Vub|=(3.82±0.14±0.22±0.11-0.52+0.88)×10-3 from B→πℓν, where the fourth error reflects the uncertainty of the form-factor normalization.
Study of B→πℓν and B→ρℓν decays and determination of |Vub|
SIMI, GABRIELE;MARGONI, MARTINO;SIMONETTO, FRANCO;STROILI, ROBERTO;VOCI, CESARE;
2005
Abstract
We present an analysis of exclusive charmless semileptonic B-meson decays based on 83×10^6 BB̅ pairs recorded with the BABAR detector at the Υ(4S) resonance. Using isospin symmetry, we measure branching fractions B(B0→π-ℓ+ν)=(1.38±0.10±0.16±0.08)×10-4 and B(B0→ρ-ℓ+ν)=(2.14±0.21±0.48±0.28)×10-4, where the errors are statistical, experimental systematic, and due to form-factor shape uncertainties. We compare the measured distribution in q2, the momentum-transfer squared, with theoretical predictions for the form factors from lattice QCD and light-cone sum rules, and extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |Vub|=(3.82±0.14±0.22±0.11-0.52+0.88)×10-3 from B→πℓν, where the fourth error reflects the uncertainty of the form-factor normalization.Pubblicazioni consigliate
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