A low-lying scalar meson nonet in a unitarized meson model

TL;DR

This paper presents a unitarized meson model that successfully describes a low-lying scalar meson nonet below 1 GeV, matching experimental scattering data through coupled-channel calculations.

Contribution

It extends a successful meson model to scalar mesons, predicting a nonet below 1 GeV with calculated pole positions and scattering observables, demonstrating the model's effectiveness.

Findings

Predicted scalar meson poles below 1 GeV

Calculated cross sections and phase shifts match experimental data

Identified a complete scalar nonet in the model

Abstract

A unitarized nonrelativistic meson model which is successful for the description of the heavy and light vector and pseudoscalar mesons yields, in its extension to the scalar mesons but for the same model parameters, a complete nonet below 1 GeV. In the unitarization scheme, real and virtual meson-meson decay channels are coupled to the quark-antiquark confinement channels. The flavor-dependent harmonic-oscillator confining potential itself has bound states epsilon(1.3 GeV), S(1.5 GeV), delta(1.3 GeV), kappa(1.4 GeV), similar to the results of other bound-state qqbar models. However, the full coupled-channel equations show poles at epsilon(0.5 GeV), S(0.99 GeV), delta(0.97 GeV), kappa(0.73 GeV). Not only can these pole positions be calculated in our model, but also cross sections and phase shifts in the meson-scattering channels, which are in reasonable agreement with the available data for pion-pion, eta-pion and Kaon-pion in S-wave scattering.