RESONANCE TRAPPING AND SATURATION OF DECAY WIDTHS

Resonance trapping appears in open many-particle quantum systems at hi gh level density when the coupling to the continuum of decay channels reaches a critical strength. Here a reorganization of the system takes place and a separation of different time scales appears. We investiga te it under the influence of additional weakly coupled channels as wel l as by taking into account the real part of the coupling term between system and continuum. We observe a saturation of the mean width of th e trapped states. Also the decay rates:saturate as a function of the c oupling strength. The mechanism of the saturation is studied in detail . In any case, the critical region of reorganization is enlarged. When the transmission coefficients for the different channels are differen t, the width distribution is broadened as compared to a chi(K)(2) dist ribution where K is the number of channels. Resonance trapping takes p lace before the broad state overlaps regions beyond the extension of t he spectrum of the closed system.