Interplay of quark and meson degrees of freedom in a near-threshold resonance: multi-channel case

Abstract

We investigate the interplay of quark and meson degrees of freedom in a physical state representing a near-threshold resonance for the case of multiple continuum channels. The aim is to demonstrate the full complexity of near-threshold phenomena. It turns out that those are especially rich, if both quark and meson dynamics generate simultaneously weakly coupled near-threshold poles in the S-matrix. We study the properties of this scenario in detail, such as t-matrix and production amplitude zeros, as well as various effects of the continuum channels interplay.