Observation of the $B^+ \to D^{*-}K^+π^+$ decay

Published 25 Apr 2017 in hep-ex | (1704.07581v2)

Abstract: The $B⁺ \to D^{{*-}K^{+\pi^+$}} decay potentially provides an excellent way to investigate charm meson spectroscopy. The decay is searched for in a sample of proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of $3~{\rm fb}^{-1}$. A clear signal is observed, and the ratio of its branching fraction to that of the $B⁺ \to D^{{*-}\pi^{+\pi^+$}} normalisation channel is measured to be \begin{equation*} \frac{\mathcal{B}(B⁺ \to D^{{*-}K^{+\pi^{+)}{\mathcal{B}(B⁺}}} \to D^{{*-}\pi^{+\pi^+)}}} = \left( 6.39 \pm 0.27 \pm 0.48 \right) \times 10^{-2} \, , \end{equation*} where the first uncertainty is statistical and the second is systematic. This is the first observation of the $B⁺ \to D^{{*-}K^{+\pi^+$}} decay.