RESONANCES IN INELASTIC-COLLISIONS - DECAY WIDTHS AND EVOLUTION OF NODAL PATTERNS FOR RESONANCE STATES

We consider a multichannel scattering system with compound state (Fesh bach) resonances originating from continuum embedded bound states unde r perturbation and analyse the structure of the scattering wave functi on in the interaction region. An extension of the Fano formalism yield s a representation of the wave function as a mixture of the unperturbe d bound state and scattering states characterized by an energy-dependi ng mixing phase. The nodal pattern of the wave function inside the int eraction region changes rapidly with the energy near the resonance. Th is change occurs on an energy scale which does not correspond to the r esonance width and can be much broader. The theoretical predictions ar e applied to a collinear collision model and compared with numerical r esults.