Dalitz plot analysis of $B_s^0 \rightarrow \bar{D}^0 K^- \pi^+$ decays

TL;DR

This paper performs a Dalitz plot analysis of $B_s^0$ decays to identify and measure properties of intermediate resonances, revealing a mixed spin-1 and spin-3 structure near 2.86 GeV/c^2 and confirming the spin-2 nature of $D^*_{s2}(2573)^-$.

Contribution

It introduces a detailed amplitude analysis of $B_s^0 ightarrow ar{D}^0 K^- ho^+$ decays, identifying new resonance structures and measuring their properties.

Findings

Discovery of a mixed spin-1 and spin-3 resonance at 2.86 GeV/c^2.

Precise measurements of masses and widths of involved resonances.

Confirmation of the spin-2 nature of $D^*_{s2}(2573)^-$.

Abstract

The resonant substructure of $B_s^0 \rightarrow \bar{D}^0 K^- \pi^+$ decays is studied with the Dalitz plot analysis technique. The study is based on a data sample corresponding to an integrated luminosity of $3.0\,{\rm fb}^{-1}$ of $pp$ collision data recorded by LHCb. A structure at $m(\bar{D}^0 K^-) \approx 2.86 {\rm GeV}/c^2$ is found to be an admixture of spin-1 and spin-3 resonances. The masses and widths of these states and of the $D^*_{s2}(2573)^-$ meson are measured, as are the complex amplitudes and fit fractions for all the $\bar{D}^0 K^-$ and $K^-\pi^+$ components included in the amplitude model. In addition, the $D^*_{s2}(2573)^-$ resonance is confirmed to be spin-2.