Branching fraction measurement of B + → ω ℓ + ν decays

We present a measurement of the $B \to \omega \ell \nu$ branching fraction based on a sample of 467 million BB pairs recorded by the BaBar detector at the SLAC PEP-2 e+e- collider. We observe $1041 \pm 133$ signal decays, corresponding to a branching fraction of $\BR(B \to \omega \ell \nu$) = (1.15 \pm 0.15 \pm 0.12) \times 10^{-4}$, where the first error is statistical and the second is systematic. The dependence of the decay rate on $q^2$, the momentum transfer squared to the lepton system, is compared to QCD predictions of the form factors based on a quark model and light-cone sum rules.