Observation of B0→¯¯¯D0K+K− and Evidence for B0s→¯¯¯D0K+K−

Abstract

The first observation of the decay B 0 → ¯¯¯ D 0 K + K − is reported from an analysis of 0.62 fb − 1 of p p collision data collected with the LHCb detector. Its branching fraction is measured relative to that of the topologically similar decay B 0 → ¯¯¯ D 0 π + π − to be B ( B 0 → ¯¯¯ D 0 K + K − ) B ( B 0 → ¯¯¯ D 0 π + π − ) = 0.056 ± 0.011 ± 0.007 , where the first uncertainty is statistical and the second is systematic. The significance of the signal is 5.8 σ . Evidence, with 3.8 σ significance, for B 0 s → ¯¯¯ D 0 K + K − decays is also presented. The relative branching fraction is measured to be B ( B 0 s → ¯¯¯ D 0 K + K − ) B ( B 0 → ¯¯¯ D 0 K + K − ) = 0.90 ± 0.27 ± 0.20 . These channels are of interest to study the mechanisms behind hadronic B decays, and open new possibilities for C P violation analyses with larger data sets.