Branching fraction measurement of B+→ωℓ+ν decays

Abstract

We present a measurement of the B + → ω ℓ + ν branching fraction based on a sample of 467 million B ¯¯¯ B pairs recorded by the BABAR detector at the SLAC PEP-II e + e − collider. We observe 1125 ± 131 signal decays, corresponding to a branching fraction of B ( B + → ω ℓ + ν ) = ( 1.21 ± 0.14 ± 0.08 ) × 10 − 4 , where the first error is statistical and the second is systematic. The dependence of the decay rate on q 2 , the invariant mass squared of the leptons, is compared to QCD predictions of the form factors based on a quark model and light-cone sum rules.