Measurements of the branching fractions B(B−→Λ¯c−Ξc′0) , B(B−→Λ¯c−Ξc(2645)0) and B(B−→Λ¯c−Ξc(2790)0)

Abstract

Using the data sample of 711 fb-1 of Ï'(4S) on-resonance data taken by the Belle detector at the KEKB asymmetric-energy electron-positron collider, we present the first measurements of branching fractions of the decays B-→Λc-Ξc′0, B-→Λc-Ξc(2645)0, and B-→Λc-Ξc(2790)0. The signal yields for these decays are extracted from the recoil mass spectrum of the system recoiling against Λc-baryons in selected B-candidates. The branching fraction of B-→Λc-Ξc(2790)0 is measured to be (1.1±0.4±0.2)×10-3, where the first uncertainty is statistical and the second is systematic. The 90% credibility level upper limits on B(B-→Λc-Ξc′0) and B(B-→Λc-Ξc(2645)0) are determined to be 6.5×10-4 and 7.9×10-4, respectively.