First evidence for the annihilation decay mode B+ → D s+φ

Abstract

Evidence for the hadronic annihilation decay mode B+ → Ds+φ is found with greater than 3σ significance. The branching fraction and CP asymmetry are measured to be B(B+ → Ds+φ)=(1.87-0.73+1.25(stat)± 0.19(syst)± 0.32(norm))× 10 -6, ACP(B+ → Ds+φ)=-0.01± 0.41(stat)± 0.03(syst).The last uncertainty on B(B+ → Ds+φ) is from the branching fractions of the B+ → Ds+D0 normalization mode and intermediate resonance decays. Upper limits are also set for the branching fractions of the related decay modes B(c)+→ D(s)+K *0, B(c)+→ D(s)+K*0 and Bc+→ D s+φ, including the result B(B+ → D+K*0)<1.8× 10-6 at the 90% credibility level. © 2013 CERN for the benefit of the LHCb collaboration.