Measurement of angular asymmetries in the decays B -> K*l(+) l(+)

Abstract

We study the lepton forward-backward asymmetry AFB and the longitudinal K polarization FL, as well as an observable P2 derived from them, in the rare decays B ! K ℓ+ℓ−, where ℓ+ℓ− is either e+e− or μ+μ−, using the full sample of 471 million BB events collected at the Υ (4S) resonance with the BABAR detector at the PEP-II e+e− collider. We separately fit and report results for the K 0(892)ℓ+ℓ− and K +(892)ℓ+ℓ− final states, as well as their combination K ℓ+ℓ−, in five disjoint dilepton mass-squared bins. An angular analysis of B+ ! K +ℓ+ℓ− decays is presented here for the first time.