Review of Scalar Mesons

TL;DR

This paper reviews the parametrisation of scalar mesons like sigma, kappa, a0(980), and f0(980), highlighting mechanisms such as Adler zero and cusp effects, and proposes a novel view on confinement involving QCD and meson exchanges.

Contribution

It provides a comprehensive review of scalar meson parametrisation and introduces a new hypothesis on the confinement potential involving QCD effects and meson exchanges.

Findings

Adler zero is crucial for sigma and kappa parametrisation.

f0(980) and a0(980) are influenced by a cusp mechanism at the KK threshold.

A new suggestion links confinement potential to QCD effects and meson exchanges.

Abstract

The formulae needed to parametrise sigma, kappa, a0(980) and f0(980) are reviewed. For sigma and kappa, the Adler zero due to Chiral Symmetry Breaking plays a crucial role. The f0(980) and a0(980) are locked to the KK threshold by a cusp mechanism which leads to a sharp peak in attraction at the threshold. This mechanism may play a wider role. A novel suggestion is that the confinement potential involves a cooperative effect between QCD effects (coloured quarks and gluons) and conventional meson exchanges.