Study of $B_c^+$ decays to the $K^+K^-\pi^+$ final state and evidence for the decay $B_c^+\to\chi_{c0}\pi^+$

TL;DR

This paper reports the first study of the decay $B_c^+ o K^+K^- o ext{final state}$, providing evidence for a specific decay mode and suggesting possible weak annihilation processes in $B_c^+$ mesons.

Contribution

It presents the first analysis of $B_c^+ o K^+K^- o ext{final state}$ decays and evidence for the decay $B_c^+ o ext{chi}_{c0} o K^+K^- ext{pi}^+$, including measurements of related branching fractions.

Findings

Evidence for $B_c^+ o ext{chi}_{c0} o K^+K^- ext{pi}^+$ with 4.0 sigma significance.

Measurement of the combined production cross-section ratio and branching fraction.

Indication of $ar b c$ weak annihilation with 2.4 sigma significance.

Abstract

A study of $B_c^+\to K^+K^-\pi^+$ decays is performed for the first time using data corresponding to an integrated luminosity of 3.0 $\mathrm{fb}^{-1}$ collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of $7$ and $8$ TeV. Evidence for the decay $B_c^+\to\chi_{c0}(\to K^+K^-)\pi^+$ is reported with a significance of 4.0 standard deviations, resulting in the measurement of $\frac{\sigma(B_c^+)}{\sigma(B^+)}\times\mathcal{B}(B_c^+\to\chi_{c0}\pi^+)$ to be $(9.8^{+3.4}_{-3.0}(\mathrm{stat})\pm 0.8(\mathrm{syst}))\times 10^{-6}$. Here $\mathcal{B}$ denotes a branching fraction while $\sigma(B_c^+)$ and $\sigma(B^+)$ are the production cross-sections for $B_c^+$ and $B^+$ mesons. An indication of $\bar b c$ weak annihilation is found for the region $m(K^-\pi^+)<1.834\mathrm{\,Ge\kern -0.1em V\!/}c^2$, with a significance of 2.4 standard deviations.