Measurements of the absolute branching fractions of B + → X cc̄ K + and B + → D̄ (*)0 π + at Belle

Abstract

We present the measurement of the absolute branching fractions of B+→Xcc̄K+ and B+→D̄(∗)0π+ decays, using a data sample of 772×106 BB̄ pairs collected at the (4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. Here, Xcc̄ 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.