Excited scalar mesons in a chiral quark model

TL;DR

This paper investigates the first radial excitations of scalar mesons using a nonlocal chiral quark model, calculating their masses and decay widths, and discusses the nature of certain resonances like f_0(1500).

Contribution

It introduces a nonlocal chiral quark model to identify and analyze the first radial excitations of scalar mesons, providing new insights into their structure and properties.

Findings

f_0(1370), f_J(1710), and a_0(1450) are identified as first radial excitations.

Calculated meson masses and decay widths match experimental data.

f_0(1500) is proposed as a glueball candidate.

Abstract

First radial excitations of the isoscalar and isovector scalar mesons f_0(400-1200), f_0(980) and a_0(980) are investigated in the framework of a nonlocal version of a chiral quark model of the Nambu--Jona-Lasinio type. It is shown that f_0(1370), f_J(1710) and a_0(1450) are the first radially excited states of f_0(400-1200), f_0(980) and a_0(980) which are ground states of the scalar meson nonet. The mesons' masses and strong decay widths are calculated. The scalar resonance f_0(1500) is supposed to be a glueball. The status of K_0^*(1430) is discussed.