Recent results form CLEOII

Abstract

I report results of a search for several rare few-body decays of the B-meson. For the decays B0→π+π-, B0→K+π-, and B0→K+K-, we limit the branching fractions (at 90% confidence) toBππ<2.9·10−5,BKπ<2.6·10−5, andBKK<0.7·10−5. While there is no statistically significant signal in any single mode, the sum ofBππ andBKπ exceeds zero with a significance of more than four standard deviations, indicating that we have observed charmless hadronic B-decays. We have also detected the decays Bo→K* (892)o γ and B−→K* (892)− γ, evidence for the quark-level process b→sγ. The average branching fraction is (4.5±1.5±0.9)·10−5, consistent with standard model predictions from electromagnetic penguin diagrams.