Study of $D^{(*)+}_{sJ}$ mesons decaying to $D^{*+} K^0_{\rm S}$ and $D^{*0} K^+$ final states

TL;DR

This paper reports the observation and analysis of several excited $D_s$ meson states decaying into $D^* K$ final states using LHCb data at 7 and 8 TeV, including first measurements of certain decay modes.

Contribution

It provides new measurements of $D_s$ meson resonances, including the first observation of $D^*_{s2}(2573)^+ o D^{*+} K^0_{ m S}$ decay and detailed properties of multiple excited states.

Findings

Observation of $D_{s1}(2536)^+$ in both channels

First observation of $D^*_{s2}(2573)^+ o D^{*+} K^0_{ m S}$ decay at 6.9 sigma

Measurement of branching fraction ratios for $D^*_{s2}(2573)^+$ decays

Abstract

A search is performed for $D^{(*)+}_{sJ}$ mesons in the reactions $pp \to D^{*+} K^0_{\rm S} X$ and $pp \to D^{*0} K^+ X$ using data collected at centre-of-mass energies of 7 and 8 TeV with the LHCb detector. For the $D^{*+} K^0_{\rm S}$ final state, the decays $D^{*+} \to D^0 \pi^+$ with $D^0 \to K^- \pi^+$ and $D^0 \to K^- \pi^+ \pi^+ \pi^-$ are used. For $D^{*0} K^+$, the decay $D^{*0} \to D^0 \pi^0$ with $D^0 \to K^- \pi^+$ is used. A prominent $D_{s1}(2536)^+$ signal is observed in both $D^{*+} K^0_{\rm S}$ and $D^{*0} K^+$ final states. The resonances $D^*_{s1}(2700)^+$ and $D^*_{s3}(2860)^+$ are also observed, yielding information on their properties, including spin-parity assignments. The decay $D^*_{s2}(2573)^+ \to D^{*+} K^0_{\rm S}$ is observed for the first time, at a significance of 6.9 $\sigma$, and its branching fraction relative to the $D^*_{s2}(2573)^+ \to D^+ K^0_{\rm S}$ decay mode is measured.