Observation of the 𝐵0→¯𝐷*0⁢𝐾+⁢𝜋− and 𝐵0𝑠→¯𝐷*0⁢𝐾−⁢𝜋+ decays

The first observations of 𝐵0→¯𝐷*⁢(2007)0⁢𝐾+⁢𝜋− and 𝐵0𝑠→¯𝐷*⁢(2007)0⁢𝐾−⁢𝜋+ decays are presented, and their branching fractions relative to that of the 𝐵0→¯𝐷*⁢(2007)0⁢𝜋+⁢𝜋− decay are reported. These modes can potentially be used to investigate the spectroscopy of charm and charm-strange resonances and to determine the angle 𝛾 of the Cabibbo-Kobayashi-Maskawa unitarity triangle. It is also important to understand them as a source of potential background in determinations of 𝛾 from 𝐵+→𝐷⁢𝐾+ and 𝐵0→𝐷⁢𝐾+⁢𝜋− decays. The analysis is based on a sample corresponding to an integrated luminosity of 5.4  fb−1 of proton-proton collision data at 13 TeV center-of-mass energy recorded with the LHCb detector. The ¯𝐷*⁢(2007)0 mesons are fully reconstructed in the ¯𝐷0⁢𝜋0 and ¯𝐷0⁢𝛾 channels with the
¯𝐷0→𝐾+⁢𝜋− decay. A novel weighting method is used to subtract background while simultaneously applying an event-by-event efficiency correction to account for resonant structures in the decays.