Evidence for the Rare Decay B+→D+sπ0

Abstract

We have searched for the rare decay B + → D + s π 0 . The analysis is based on a sample of 232 × 10 6 Υ ( 4 S ) → B ¯¯¯ B decays collected with the BABAR detector at the SLAC PEP-II e + e − storage ring. We find 19.6 signal events, corresponding to a significance of 4.7 σ . The extracted signal yield including statistical and systematic uncertainties is 20.1 + 6.8 + 0.4 − 6.0 − 1.5 , and we measure B ( B + → D + s π 0 ) = ( 1.5 + 0.5 − 0.4 ± 0.1 ± 0.2 ) × 10 − 5 , where the first uncertainty is statistical, the second is systematic, and the last is due to the uncertainty on the D + s decay and its daughter decay branching fractions.