Suppression of PiNN(1535) Coupling in the QCD Sum Rule

Abstract

The \pi NN^* and \eta NN^* coupling constants are studied in the QCD sum rule ($N^* \equiv N(1535)). We investigate the two point functions between the vacuum and a one meson state in the soft meson limit. The operator product expansion is explicitly performed up to terms of dimension eight. We find that \gpNR vanishes to this order, while \geNR has a finite contribution. The vanishing of \gpNR is a rigorous consequence in the chiral limit. The results of the QCD sum rule are compared with those of low energy effective models.

Comments: 6pp, LaTeX, Talk given by A.H. at YITP workshop ''Recent developments in QCD and hadron physics", Kyoto, December (1996), to appear in the proceedings