Calculation of the decay constants of scalar mesons - art. no. 074017

The purpose of our work is to provide further evidence for the utility of o ur generalized Nambu-Jona-Lasinio model in describing the properties of lig ht mesons. In this work we develop methods for the calculation of the decay constants of scalar mesons. Our model makes definite predictions of how sc alar mesons should be organized into nonets and we use our calculation of t he decay constants to support our predictions. The assignment of scalar mes ons to various nonets is problematic, with various choices made in the lite rature for the sigma (500-600), f(0)(980), a(0)(980), f(0)(1370), K-0*(1430 ), and f(0)(1500). Maltman has suggested that one can gain information as t o how these nonets should be chosen by determining the meson decay constant s of the scaler mesons. In particular, he studies the a(0)(980), a(0)(1450) , and K-0*(1430) resonances using QCD sum rule techniques and other methods . He concludes that the a(0)(980) and K-0*(1430) have similar decay constan ts and therefore have similar structure, (We have come to the same conclusi on by an entirely different analysis, making use of our generalized Nambu-J ona-Lasinio (NJL model, which includes a covariant model of confinement.) I n the case of the no(980) we obtain a result for the decay constant that is about 50% larger than that of Maltman, while for the a(0)(1450) and K-0*(1 430) our results are somewhat smaller than his. Our results suggest that th e a(0)(980) may have a significant K (K) over bar component, which would re duce our theoretical value. The implication of our results and those of Mal tman for the organization of scalar mesons into nonets is discussed.