Measurement of CP observables in B± → D(⁎)K± and B± → D(⁎)π± decays

Abstract

Measurements of CP observables in B± → D(∗)K ± and B± → D(∗) π± decays are presented, where D(∗) indicates a neutral D or D∗ meson that is an admixture of D(∗)0 and D¯ (∗)0 states. Decays of the D∗ meson to the Dπ0 and Dγ final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the B candidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K ±π∓, K + K − and π+π− final states. The analysis uses a sample of charged B mesons produced in pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0 fb−1 taken at centre-of-mass energies of √s = 7, 8 and 13 TeV, respectively. The study of B± → D∗K ± and B± → D∗π± decays using a partial reconstruction method is the first of its kind, while the measurement of B± → D K ± and B± → Dπ± decays is an update of previous LHCb measurements. The B± → D K ± results are the most precise to date.