Probing the nature of $D_1 K$ and $D_2 K$ molecules through $D_s^{(*)}\pi\pi$ and $D_{s0(s1)}\pi$ decays

TL;DR

This paper investigates the decay behaviors of $D_1K$ and $D_2K$ molecular states, predicting narrow peaks and large isospin-violating decay widths to aid experimental identification.

Contribution

It introduces theoretical predictions of decay signatures for $D_1K$ and $D_2K$ molecules using heavy hadron chiral perturbation theory and the chiral unitary approach.

Findings

Triangle singularities produce narrow peaks near thresholds.

Large partial widths in isospin-violating decays.

Predictions offer experimental signatures for molecular states.

Abstract

We study the two- and three-body decays of the $I=0$ $D_1K$ and $D_2K$ molecular states $T_{c\bar{s}1}^*$ and $T_{c\bar{s}2}^*$ into $D_s^{(*)}$ mesons and pions. Triangle singularities produce narrow peaks in the $D_s^*\pi$ and $D_s\pi$ invariant mass spectra near the $D^*K$ and $DK$ thresholds. The isospin-violating two-body decays $T_{c\bar{s}1}^*\to D_{s1}(2460)\pi^0$, $T_{c\bar{s}2}^*\to D_{s1}(2460)\pi^0$, and $T_{c\bar{s}2}^*\to D_{s0}^*(2317)\pi^0$ exhibit large partial widths, reflecting the strong couplings inherent to molecular states. These predictions, obtained within heavy hadron chiral perturbation theory and the chiral unitary approach, provide complementary signatures for identifying $D_1K$ and $D_2K$ molecules at experiments.