Radial excitations of scalar, η, and η′ mesons in a chiral quark model

Abstract

First radial excitations of the scalar meson nonet and pseudoscalar mesons \eta, \eta' are described in a nonlocal chiral quark model of the Nambu--Jona-Lasinio type with 't Hooft interaction. In this model simple form factors are used, which allows us to describe first radial excitations of the mesons and to conserve the gap equations describing spontaneous breaking of chiral symmetry in the standard form. The external parameters of form factors are fixed by masses of excited pseudoscalar mesons and the same form factors are used for predicting the masses of excited scalar mesons. Strong decays of excited scalar mesons and \eta, \eta' mesons are described in satisfactory agreement with experiment.