Updated search for $B_c^+$ decays to two charm mesons

TL;DR

This study searches for specific $B_c^+$ meson decays into two charm mesons using LHCb data, setting upper limits on branching fractions and observing a 3.4 sigma excess for one decay mode.

Contribution

The paper provides updated upper limits on $B_c^+$ decay branching fractions and reports a potential signal for $B_c^+ o D_s^+ ar{D}^0$ decay, enhancing understanding of $B_c^+$ decay modes.

Findings

Upper limits set for 14 $B_c^+$ decay modes.

An excess with 3.4 sigma significance for $B_c^+ o D_s^+ ar{D}^0$.

Improved constraints on $B_c^+$ decay branching fractions.

Abstract

A data set corresponding to an integrated luminosity of $9 \text{fb}^{-1}$ of proton-proton collisions collected by the LHCb experiment has been analysed to search for $B_c^+ \to D^{(*)+}_{(s)} \overset{\scriptstyle (-)}{D}{}^{(*)0}$ decays. The decays are fully or partially reconstructed, where one or two missing neutral pions or photons from the decay of an excited charm meson are allowed. Upper limits for the branching fractions, normalised to $B^+$ decays to final states with similar topologies, are obtained for fourteen $B_c^+$ decay modes. For the decay $B_c^+ \to D_s^+ {\overline{D}}^0$, an excess with a significance of 3.4 standard deviations is found.