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

Abstract

Measurements of CPobservables in B±→D(∗)K±and B±→D(∗)π±decays are presented, where D(∗)indicates a neutral Dor D∗meson that is an admixture of D(∗)0and ¯ D(∗)0states. Decays of the D∗meson to the Dπ0and Dγfinal states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the Bcandidate invariant mass distribution. Decays of the Dmeson are fully reconstructed in the K±π∓, K+K−and π+π−final states. The analysis uses a sample of charged Bmesons produced in ppcollisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0fb−1taken at centre-of-mass energies of √s=7, 8 and 13TeV, 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±→DK±and B±→Dπ±decays is an update of previous LHCb measurements. The B±→DK±results are the most precise to date.