Theory of kaon-nuclear systems

TL;DR

This paper reviews the theoretical understanding of antikaon-nucleon interactions, the formation of kaonic nuclei, and their implications for hadron spectroscopy and nuclear physics.

Contribution

It provides a comprehensive overview of the modern theoretical models of kaon-nuclear systems, including the nature of the $ar{K}N$ interaction and the properties of kaonic nuclei.

Findings

The $ar{K}N$ interaction can generate quasi-bound states like $ar{K}N$ and kaonic nuclei.

The $ar{K}N$ interaction explains the $ ext{Lambda}(1405)$ resonance as a quasi-bound state.

Kaonic nuclei exhibit unique properties relevant to nuclear many-body physics.

Abstract

The strong interaction between an antikaon and a nucleon is at the origin of various interesting phenomena in kaon-nuclear systems. In particular, the interaction in the isospin $I=0$ channel is sufficiently attractive to generate a quasi-bound state, the $\Lambda(1405)$ resonance, below the $\bar{K}N$ threshold. Based on this picture, it may be expected that the $\bar{K}N$ interaction also generates quasi-bound states in kaon-nuclear systems, sometimes called kaonic nuclei. At the same time, the $\bar{K}N$ quasi-bound picture of the $\Lambda(1405)$ is also related to the discussion of hadronic molecules in hadron spectroscopy. Here an overview is presented of the theoretical studies developed for kaon-nucleon and kaon-nuclear systems. We start from the modern understanding of the $\Lambda(1405)$ resonance. We then discuss the $\bar{K}N$ interaction and various aspects of few-body kaonic nuclei. Heavier kaon-nuclear systems are examined from the viewpoint of nuclear many-body physics, with focus on the properties of antikaons in nuclear matter. Related topics, such as the $K^{-}p$ momentum correlation functions in high-energy collisions and the studies of kaonic atoms, are also discussed.