The $D_{s1}(2460) \to D_s \pi^+ \pi^- $ decay from a $D_{s1}$ molecular perspective

Abstract

We conduct a theoretical study of the $ D_{s1}(2460) \to D_s \pi^+ \pi^- $ decay from the perspective that the $D_{s1}$ is a molecular state, built mostly from the $D^* K$ and $D_s^* \eta$ components. The $D^*$ and $D_s^*$ mesons are allowed to decay into two pseudoscalars, with one of them merging with the other pseudoscalar that forms the $D_{s1}$ state, ultimately leading to the $\pi^+ \pi^- D_s$ final state. This results in a triangle diagram mechanism where all theoretical ingredients are well-known, leading to a free parameter framework. We evaluate the mass distributions of particle pairs and find good agreement with the experimental distributions of a recent LHCb experiment, providing strong support to the molecular picture of the $D_{s1}(2460)$ state. We also discuss the role played by the scalar mesons $f_0(500)$ and $f_0(980)$, at odds with the interpretation of the experimental analysis.