Remark on the effective range approach to the f_0-a_0 mesons

Abstract

Discussion of apparently simple issues related to the resonance close to threshold may lead to misleading results. We clarify some subtle points, in particular the relation between Breit-Wigner and effective range approaches to the f_0-a_0 mesons.

Comments: LaTeX, 8 pages, no figures, minor corrections, to appear in Phys.Lett.B