Study of $B_c^+$ meson decays to charmonia plus multihadron final states

TL;DR

This study reports the first observation of the decay $B_c^+ o J/psi K^+ K^-   $ and evidence for others, measuring branching fraction ratios using LHCb data at multiple energies.

Contribution

It provides new measurements of $B_c^+$ decay modes, including first observations and evidence, expanding understanding of heavy meson decay channels.

Findings

First observation of $B_c^+ o J/psi K^+ K^-   $ decay.

Evidence for $B_c^+ o J/psi 4  $ decay.

Confirmation of $B_c^+ o  ext{S} o J/psi  $ decay.

Abstract

Four decay modes of the $B_c^+$ meson into a $J/\psi$ meson and multiple charged kaons or pions are studied using proton-proton collision data, collected with the~LHCb detector at centre-of-mass energies of 7, 8, and 13~TeV and corresponding to an integrated luminosity of $9$~fb$^{-1}$. The decay $B_c^+\to J/\psi K^+ K^- \pi^+ \pi^+ \pi^-$ is observed for the first time, and evidence for the $B_c^+\to J/\psi 4\pi^+ 3\pi^-$ decay is found. The decay $B_c^+\to J/\psi 3\pi^+ 2\pi^-$ is observedand and the previous observation of the $B_c^+\to\psi(2S) \pi^+ \pi^+ \pi^-$ decay is confirmed using the $\psi(2S) \to J/\psi \pi^+ \pi^-$ decay mode. Ratios of the branching fractions of these four $B_c^+$ decay channels are measured.