Observation of the $B^0\rightarrow\overline{D}^{*0}K^{+}\pi^{-}$ and $B_s^0\rightarrow\overline{D}^{*0}K^{-}\pi^{+}$ decays

TL;DR

This paper reports the first observation of specific B meson decays involving D*0, K, and pi particles, providing data crucial for understanding charm spectroscopy and CKM angle gamma, with implications for background modeling in related measurements.

Contribution

First observation of B0 and Bs0 decays to D*0 K pi modes, with relative branching fractions measured using a novel background subtraction and efficiency correction method.

Findings

First observation of these decay modes.

Branching fractions relative to a known decay.

Potential use in charm spectroscopy and CKM angle gamma measurements.

Abstract

The first observations of $B^0\rightarrow\overline{D}^{*}(2007)^{0}K^{+}\pi^{-}$ and $B_s^0\rightarrow\overline{D}^{*}(2007)^{0}K^{-}\pi^{+}$ decays are presented, and their branching fractions relative to that of the $B^0\rightarrow\overline{D}^{*}(2007)^{0}\pi^{+}\pi^{-}$ decay are reported. These modes can potentially be used to investigate the spectroscopy of charm and charm-strange resonances and to determine the angle $\gamma$ of the CKM unitarity triangle. It is also important to understand them as a source of potential background in determinations of $\gamma$ from $B^{+}\rightarrow DK^{+}$ and $B^{0}\rightarrow DK^{+}\pi^{-}$ decays. The analysis is based on a sample corresponding to an integrated luminosity of $5.4 ~\rm{fb}^{-1}$ of proton--proton collision data at $13 ~\rm{TeV}$ centre-of-mass energy recorded with the LHCb detector. The $\overline{D}^{*}(2007)^{0}$ mesons are fully reconstructed in the $\overline{D}^{0}\pi^{0}$ and $\overline{D}^{0}\gamma$ channels, with the $\overline{D}^{0} \rightarrow K^{+}\pi^{-}$ decay. A novel weighting method is used to subtract background while simultaneously applying an event-by-event efficiency correction to account for resonant structures in the decays.