New measurements of $B_c^{+}$ decays into single charm final states

Abstract

Using proton-proton collision data corresponding to an integrated luminosity of $9{\text{fb}}^{-1}$ collected by the LHCb experiment, searches are performed for $B_c^{+}$ mesons decaying to a charm and a charmless meson pair. Five products of branching fraction, $\mathcal{B}(B_c^{+}\to DX)$, and fragmentation ratio $f_c/f_u$ are reported, \begin{align*} R_{D^+ K^{*0}} &= ( 1.42 \pm 0.23 \pm 0.07 \pm 0.11 ) \times 10^{-6}, \\ R_{D^{*0} K^+} &= (1.46 \pm 0.30 \pm 0.11 \pm 0.05 ) \times 10^{-6}, \\ R_{D^+_s ϕ}\ \ \ &= ( 4.0\pm 1.3 \pm 0.2 \pm 0.5) \times 10^{-7 }, \\ R_{D^0 K^+}\ &= ( 9.7 \pm 1.0 \pm 0.4 \pm 0.3 ) \times 10^{-7}, \\ R_{D^0 π^+}\ &<\ 1.4 \times 10^{-7}\ \text{at 95\% CL}. \end{align*} In each case, the first uncertainty is statistical, the second is systematic and the third includes external uncertainties. The first result is a first observation, the second and third exhibit clear evidence and the fourth improves the precision of previous measurements by a factor two. Additionally, the $CP$ asymmetry in $B_c^{+}\to D^0{K}^{+}$ decays is measured and found to be compatible with zero.

All figures and tables, along with any supplementary material and additional information, are available at https://lhcb-glance.cern.ch/alcm/public/analysis/full-details/1627