Observation of the suppressed Λb0 →dpK- decay with D →k+π- and measurement of its CP asymmetry

Abstract

A study of Λb0 baryon decays to the DpK- final state is presented based on a proton-proton collision data sample corresponding to an integrated luminosity of 9 fb-1 collected with the LHCb detector. Two Λb0 decays are considered, Λb0→DpK- with D→K-π+ and D→K+π-, where D represents a superposition of D0 and D¯0 states. The latter process is expected to be suppressed relative to the former, and is observed for the first time. The ratio of branching fractions of the two decays is measured, and the CP asymmetry of the suppressed mode, which is sensitive to the Cabibbo-Kobayashi-Maskawa angle γ, is also reported.