Strangeness is the key: from $\bar{K}N$ to $\bar{D}_s D K$

TL;DR

This paper reviews recent advances in understanding how strangeness influences hadronic interactions, highlighting the role of kaons as Nambu-Goldstone bosons and their connection to exotic particles like $ar{K}N$ and $DK$ molecules.

Contribution

It provides a comprehensive overview of the significance of strangeness in hadronic physics, emphasizing the molecular nature of certain exotic states and potential three-body hadronic molecules.

Findings

$ar{K}N$ and $DK$ can be understood as hadronic molecules.

Strangeness plays a crucial role in strong interactions and exotic hadron formation.

Potential existence of three-body hadronic molecules involving kaons.

Abstract

The kaon, the lightest hadron containing a strangeness quark, is very peculiar. It is a Nambu-Goldstone boson, but significantly heavier than the pion. As a result, its interaction with a matter particle, such as the nucleon or a heavy-light meson, such as the $D$ meson, is completely determined by chiral dynamics and much stronger than its pion cousin. The strong attractive interaction has brought us many surprises and is manifested in the peculiar nature of many particles, such as the mysterious $\Lambda(1405)$ and $D_{s0}^*(2317)$. These two particles can be understood as $\bar{K}N$ and $DK$ hadronic molecules, respectively. They also imply the existence of three-body hadronic molecules that await future discovery. In this talk, I review some recent developments in our understanding of hadronic interactions involving the kaon.