Improved sensitivity to the CKM phase γ through binning phase space in B ??→? DK ?, D?→? K + π ? π ? π + decays

摘要

A binning scheme is proposed forD→K+π?π?π+phase space that will improve the sensitivity of aB?→DK?analysis to the angleγof the Cabibbo-Kobayashi-Maskawa Unitarity Triangle. The scheme makes use of amplitude models recently reported by the LHCb collaboration. Assuming that a four-bin scheme optimised on the models retains a similar sensitivity when applied in data, it is estimated that the statistical uncertainty onγfrom theB-meson sample so far collected by the LHCb experiment will be as low as 5 degrees. This will be one of the most precise results available for any single decay mode in aB?→DK?measurement. Quantum-correlatedDDˉdata accumulated by the CLEO-c experiment are analysed to provide first constraints on the coherence factors and average strong-phase differences in the four bins, which are necessary inputs for the measurement. These constraints are compared with the predictions of the model, and consequences for the measurement ofγare discussed.