Carregant...
Fitxers
Tipus de document
ArticleVersió
Versió publicadaData de publicació
Tots els drets reservats
Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/130865
Study of ¯¯B → Xuℓ¯ν decays in B¯¯B events tagged by a fully reconstructed B-meson decay and determination of |Vub|
Títol de la revista
Director/Tutor
ISSN de la revista
Títol del volum
Recurs relacionat
Resum
We report measurements of partial branching fractions for inclusive charmless semileptonic B decays ¯¯¯ B → X u ℓ ¯ ν and the determination of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element | V u b | . The analysis is based on a sample of 467 × 10 6 Υ ( 4 S ) → B ¯¯¯ B decays recorded with the BABAR detector at the PEP-II e + e − storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions Δ B in several restricted regions of phase space and determine the CKM element | V u b | based on different QCD predictions. For decays with a charged lepton momentum p ∗ ℓ > 1.0 GeV in the B meson rest frame, we obtain Δ B = ( 1.80 ± 0.13 stat ± 0.15 sys ± 0.02 theo ) × 10 − 3 from a fit to the two-dimensional M X − q 2 distribution. Here, M X refers to the invariant mass of the final state hadron X and q 2 is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract | V u b | = ( 4.33 ± 0.24 exp ± 0.15 theo ) × 10 − 3 as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for ¯¯¯ B 0 and B − decays and derive a limit on the isospin breaking in ¯¯¯ B → X u ℓ ¯ ν decays.
Matèries (anglès)
Citació
Citació
GARRA TICÓ, Jordi, GRAUGÉS POUS, Eugeni, BABAR Collaboration. Study of ¯¯B → Xuℓ¯ν decays in B¯¯B events tagged by a fully reconstructed B-meson decay and determination of |Vub|. _Physical Review D_. 2012. Vol. 86, núm. 3, pàgs. 32004. [consulta: 22 de gener de 2026]. ISSN: 1550-7998. [Disponible a: https://hdl.handle.net/2445/130865]