Searches are presented for B₂^+ D h^+ h^- decays, where D is a charmed meson and h^ is a charged pion or kaon, using pp collision data collected by the LHCb experiment corresponding to an integrated luminosity of 9~fb^-1. The decays Bc^+ D^+ K^+π^-, Bc^+ D^*+ K^+π^- and Bc^+ Dₛ^+ K^+ K^- are observed for the first time. Their branching fractions, expressed as ratios relative to that of the Bc^+ Bₛ⁰π^+ decay, are determined to be align* R (Bc^+ D^+ K^+π^-) = (1. 96 0. 23 0. 08 0. 10) 10^-3, &\\ R (Bc^+ D^*+ K^+π^-) = (3. 67 0. 55 0. 24 0. 20) 10^-3, &\\ R (Bc^+ Dₛ^+ K^+ K^-) = (1. 61 0. 35 0. 13 0. 07) 10^-3, align* where the first uncertainty is statistical, the second is systematic, and the third is due to the limited precision on the D-meson branching fractions. The decay channels proceed primarily through excited K⁰ or D⁰ resonances or ϕ mesons, and open a new avenue for studies of charge-parity violation in beauty mesons.
collaboration et al. (2025) studied this question.