Light Scalar Mesons

Abstract

We review how a certain effective chiral Lagrangian approach to pi pi scattering, pi K scattering and eta-prime decay to eta pi pi provides evidence for the existence of light scalars sigma(550) and kappa(900) as well as describing the f0(980) and the a0(980). An attempt to fit these into a nonet suggests that their structure is closer to a dual quark-dual antiquark than to a quark-antiquark. A possible mechanism to explain the next higher mass scalar nonet is also proposed.

Comments: 10 pages, 4 figures, talk given at Hadron Physics: Effective Theories of Low Energy QCD, Coimbra, Portugal, Sept. 1999