Eur. Phys. J. A (2010) 44: 93-103
https://doi.org/10.1140/epja/i2010-10929-7

Regular Article - Theoretical Physics

Interplay of quark and meson degrees of freedom in a near-threshold resonance

¹ Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218, Moscow, Russia
² Institut für Kernphysik (Theorie) and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425, Jülich, Germany

^* e-mail: nefediev@itep.ru

Received: 5 January 2010
Accepted: 24 January 2010
Published online: 20 February 2010

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 a single continuum channel. We demonstrate that such a near-threshold resonance may possess quite peculiar properties if both quark and meson dynamics generate weakly coupled near-threshold poles in the S -matrix. In particular, the scattering t -matrix may possess zeros in this case. We also discuss possible implications for production reactions as well as studies within lattice QCD.