One way to verify the molecular picture of exotic hadrons --from $DK$ to $DDK/D\bar{D}^{(*)}K$

TL;DR

This paper explores the possibility that certain exotic hadrons are molecular states composed of three or more hadrons, predicts the existence of specific $DDK$, $Dar{D}K$, and $Dar{D}^*K$ molecules, and suggests their decay modes for experimental detection.

Contribution

It introduces a theoretical framework to predict three-hadron molecular states based on two-body interactions, extending the molecular picture of exotic hadrons.

Findings

Likely existence of $DDK$, $Dar{D}K$, and $Dar{D}^*K$ molecular states.

Reproduction of known three-body systems like deuteron-triton and $ar{K}NN$ using the approach.

Predictions of strong decay modes to guide experiments.

Abstract

Starting from 2003, a large number of the so-called exotic hadrons, such as $X(3872)$ and $D_{s0}^*(2317)$, were discovered experimentally. Since then, understanding the nature of these states has been a central issue both theoretically and experimentally. As many of these states are located close to two hadron thresholds, they are believed to be molecular states or at least contain large molecular components. We argue that if they are indeed molecular states, in the way that the deuteron is a bound state of proton and neutron, then molecular states of three or more hadrons are likely, in the sense that atomic nuclei are bound states of nucleons. Following this conjecture, we study the likely existence of $DDK$, $D\bar{D}K$, and $D\bar{D}^{*}K$ molecular states. We show that within the theoretical uncertainties of the two-body interactions deduced, they most likely exist. Furthermore, we predict their strong decays to help guide future experimental searches. In addition, we show that the same approach can indeed reproduce some of the known three-body systems from the two-body inputs, such as the deuteron-triton and the $\Lambda(1405)$-$\bar{K}NN$ systems.