Measurement of the B[superscript +] → ωℓ[superscript +]ν branching fraction with semileptonically tagged B mesons

• Main Authors: Cowan, Ray Franklin (Contributor), Dujmic, D. (Contributor), Sciolla, Gabriella (Contributor), Flood, Kevin T. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2014-02-10T13:41:40Z.
• Subjects: Article
• Online Access: Get fulltext

 We report a measurement of the branching fraction of the exclusive charmless semileptonic decay B[superscript +]→ ωℓ[superscript +]ν, where ℓ is either an electron or a muon. We use samples of B[superscript +] mesons tagged by a reconstructed charmed semileptonic decay of the other B meson in the event. The measurement is based on a data set of 426.1  fb[superscript −1] of e[superscript +]e[superscript −] collisions at a center-of-mass energy of 10.58 GeV recorded with the BABAR detector at the PEP-II asymmetric-energy e[superscript +]e[superscript −] storage rings. We measure a branching fraction of B(B[superscript +] → ωℓ[superscript +]ν) = (1.35 ± 0.21 ± 0.11) × 10[superscript −4], where the uncertainties are statistical and systematic, respectively. We also present measurements of the partial branching fractions in three bins of q[superscript 2], the invariant-mass squared of the lepton-neutrino system, and we compare them to theoretical predictions of the form factors.