CHAOS-DRIVEN DECAY OF NUCLEAR GIANT-RESONANCES - QUANTUM ROUTE TO SELF-ORGANIZATION

The influence of background states with increasing level of complexity on the strength distribution of the isoscalar and isovector giant quadrupole resonance in Ca-40 is studied. It is found that the background characteristics, typical for chaotic systems, strongly affect the fluctuation properties of the strength distribution. In particular, the small components of the wave function obey a scaling law analogous to self-organized systems at the critical state. This appears to be consistent with the Porter-Thomas distribution of the transition strength.