Measurements of the absolute branching fractions of B+→XccˉK+ and B+→Dˉ(*)0π+ at Belle

摘要

We present the measurement of the absolute branching fractions of B+→XccˉK+ and B+→Dˉ(*)0π+ decays, using a data sample of 772×106??BBˉ pairs collected at the ?(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e? collider. Here, Xccˉ denotes ηc, J/ψ, χc0, χc1, ηc(2S), ψ(2S), ψ(3770), X(3872), and X(3915). We do not observe significant signals for X(3872) or X(3915) and set the 90%?confidence level upper limits at B(B+→X(3872)K+)2.6×10?4 and B(B+→X(3915)K+)2.8×10?4. These represent the most stringent upper limit for B(B+→X(3872)K+) to date and the first limit for B(B+→X(3915)K+). The measured branching fractions for ηc and ηc(2S) are the most precise to date, B(B+→ηcK+)=(12.0±0.8±0.7)×10?4 and B(B+→ηc(2S)K+)=(4.8±1.1±0.3)×10?4, where the first and second uncertainties are statistical and systematic, respectively.