$B^+_c$ meson production, decays and properties at LHCb

We report the first study of the $B_c^+ \to K^+K^-\pi^+$ decay and an update of the measurement of the ratio of branching fractions $R_{K/\pi} \equiv {\cal B}(B_c^+\to J/\psi K^+)/{\cal B}(B_c^+\to J/\psi\pi^+)$. Both results use an integrated luminosity of $3.0fb^{-1}$ collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV. We measure $B_c^+ \to \chi_{c0}(\to K^+ K^-)\pi^+$ with $4.0\sigma$ significance and $\frac {\sigma(B_c^+)} {\sigma(B^+)}$ X ${\cal B}(B_c^+ \to \chi_{c0}\pi^+)$ to be $(9.8^{+3.4}_{-3.0}(stat) \pm 0.8(syst))$ X $10^{-6}$. The contribution of $B_c^+ \to K^+K^-\pi^+$ via $\overline{b}c$ weak annihilation for $m(K^-\pi^+) < 1.834 GeV$ is measured with $2.4\sigma$ significance. The ratio of branching fractions $R_{K/\pi} \equiv {\cal B}(B_c^+ \to J/\psi K^+) / {\cal B}(B_c^+ \to J/\psi \pi^+)$ is measured to be $R_{K/\pi} = 0.079 \pm 0.007(stat) \pm 0.003(syst)$. This result significantly improves the previous LHCb measurement.