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

Abstract

The πNN^* and ηNN^* coupling constants are studied based on the two point functions between the vacuum and a one meson state in the soft meson limit. In terms of a suitably constructed interpolating field for the nucleon and resonances, we have found that the πNN^* couplings vanish, while ηNN^* couplings remain finite. This result explains a relatively suppressed coupling of πNN(1535) as compared with others. We compare the present result with predictions of low energy effective models.

6 pp, LaTeX