Search for B+ --> mu+ nu With Inclusive Reconstruction at BaBar. The Babar Collaboration

摘要

We search for the purely leptonic decay B(sup (+-)) (yields) (mu)(sup (+-))(nu)(sub (mu)) in the full BABAR dataset, having an integrated luminosity of approximately 426 fb(sup -1). We adopt a fully inclusive approach, where the signal candidate is identified by the highest momentum lepton in the event and the companion B is inclusively reconstructed without trying to identify its decay products. We set a preliminary upper limit on the branching fraction of (Beta)(B(sup (+-)) (yields) (mu)(sup (+-))(nu)(sub (mu))) < 1.3 x 10(sup -6) at the 90% confidence level, using a Bayesian approach.