Two- and three-body structure of the Y(4660)

TL;DR

This paper explores the internal structure of the Y(4660) particle by analyzing it as either a two-body or three-body bound state involving mesons, focusing on the interplay of different energy scales and substructure effects.

Contribution

It provides a detailed analysis of the conditions under which the substructure of the f_0(980) meson can be neglected in modeling the Y(4660).

Findings

Identification of key energy scales affecting the Y(4660) structure.

Conditions where f_0(980) substructure can be ignored.

Insights into three-meson bound state formation.

Abstract

We study general features of three-meson bound states using the Y(4660) as an example. Here the Y(4660) is assumed to be either a two-body bound state of the f_0(980), itself a bound state of K and Kbar, and the psi'= psi(2s), or a three-body bound state of psi', K, and Kbar. In particular, we investigate in detail the interplay of the various scales inherent in the problem, namely the f_0 binding energy, the Y binding energy, and the K-psi' scattering length. This allows us to understand under which circumstances the substructure of the f_0(980) can be neglected in the description of the Y(4660).