LEVEL AND WIDTH STATISTICS FOR A DECAYING CHAOTIC SYSTEM

The random matrix ensemble of discretized effective non-hermitian hami ltonians is used for studying local correlations and fluctuations of e nergies and widths in a quantum system where intrinsic levels are coup led to the continuum via a common decay channel. With the use of analy tical estimates and numerical simulations, generic properties of stati stical observables are obtained for the regimes of weak and strong con tinuum coupling as well as for the transitional region. Typical signal s of the transition (width collectivization, disappearance of level re pulsion at small spacings and violation of uniformity along the energy axis) are discussed quantitatively.