Generalized Weinberg's approach to the a0/f0 case

Abstract

The problem of whether it is possible to distinguish composite from elementary particles is studied in the framework of Weinberg's approach. The possibility to extend this approach to the case of unstable particles in the presence of inelastic channels is considered. The interplay between the low-energy scattering data and the admixture of a bare state in the resonance is discussed, and the implications for the a0(980)/f0(980) case are outlined.

Comments: LaTeX2e, 5 pages, 2 figures, to appear in the proceedings of the HADRON03 conference, Aschaffenburg, Germany. September 2003, typo corrected