Towards an understanding of the light scalar mesons

Abstract

Although studied for many years the nature of the light scalar mesons remains controversial. Here we shall present a method, applicable for s-wave states located close to a threshold, that allows one to quantify the molecular part of a given state. When applied to the $f_0(980)$ a dominance of the molecular component is found. In the second part we show that requirements of field theoretic consistency and chiral symmetry, when applied to the scattering of light pseudo--scalars, naturally lead to the appearance of dynamical poles in the scalar sector. A program is proposed on how to further investigate experimentally the mixing between these dynamical states and possible genuine quark states.

6 pages; invited talk at the IVth International Conference on Quarks and Nuclear Physics (QNP06), Madrid, June 5th-10th 2006

References in corpus (6)

• A low-lying scalar meson nonet in a unitarized meson model
• The nature of $\sigma$, $\kappa$, $a_0(980)$ and $f_0(980)$
• Effects of S-wave thresholds
• The e+ e- -> P1 P2 gamma processes close to the Phi peak: toward a model-independent analysis
• Once more about the K\bar K molecule approach to the light scalars
• Comment on "Once more about the KK molecule approach to the light scalars"

Cited by in corpus (10)

• Glueballs, Hybrids, Multiquarks. Experimental facts versus QCD inspired concepts
• Scalar mesons in a finite volume
• Two-photon decays of hadronic molecules
• Bound states on the lattice with partially twisted boundary conditions
• How and when can one identify hadronic molecules in the baryon spectrum
• Comment on "Once more about the KK molecule approach to the light scalars"
• S-wave and P-wave pion-pion and kaon-pion contributions to three-body decay processes in the Resonance-Spectrum Expansion
• Pion reactions on two--nucleon systems
• Pion-pion scattering near threshold in the Resonance-Spectrum Expansion
• Study of the hadronic production of kaon pairs below the threshold for the phi meson