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

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 ${\mathrm{f}\mathrm{b}}^{-1}$ 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 $(9.8_{-3.0}^{+3.4}(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t})\pm 0.8(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}))\times {10}^{-6}$. 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 $m(K^{-}{\pi }^{+})<1.834\mathrm{G}\mathrm{e}\mathrm{V}\text{\hspace{0.17em}⁣}\mathrm{/}{c}^2$, with a significance of 2.4 standard deviations.