The $D_{s0}(2590)^+$ as the dressed $c\bar s(2^1S_0)$ meson in a coupled-channels calculation

TL;DR

This paper investigates the $D_{s0}(2590)^+$ meson as a dressed $car s(2^1S_0)$ state using a coupled-channels approach, revealing how meson-meson interactions influence its mass and properties.

Contribution

It introduces a coupled-channels calculation including multiple meson-meson channels to explain the low mass of the $D_{s0}(2590)^+$ meson, incorporating the effects of nearby thresholds.

Findings

The $D_{s0}(2590)^+$ can be described as a dressed $car s(2^1S_0)$ state.

Coupling to meson-meson channels significantly reduces the predicted mass.

The model provides insights into the resonance's width and production line shape.

Abstract

The recent discovery of the $D_{s0}(2590)^+$ meson by the LHCb Collaboration has stimulated the analysis of meson-meson channels effects in the two-body quark-antiquark meson spectrum. This resonance, assigned to the radial excitation of the pseudoscalar $D_s^+$ meson, has a mass much lower than the predictions of naive quark models, which could indicate a non-negligible $D^{(*)}K^{(*)}$ coupling which reduces its mass. Based on the importance of nearby meson-meson thresholds in the dynamics of P-wave $D_s$ mesons such as the $D_{s0}^*(2317)^+$ and $D_{s1}(2460)^+$, in this work we perform a coupled-channels calculation including the $D^{(*)}K^{(*)}$, $D_s^{(*)}\omega$ and $D_s^*\eta$ channels, and study the impact of incorporating those channels in the mass of the bare $c\bar s$. The coupling between two and four-quark sectors is done by means of the $^3P_0$ mechanism, with all the parameters constrained from previous studies of the heavy meson spectroscopy. The masses, widths and production line shapes of the resulting state are analyzed.