Multiscale fluctuations in nuclear response

Abstract

The nuclear collective response is investigated in the framework of a doorway picture in which the spreading width of the collective motion is described as a coupling to more and more complex configurations. It is shown that this coupling induces fluctuations of the observed strength. In the case of a hierarchy of overlapping decay channels, we observe Ericson fluctuations at different scales. Methods for extracting these scales and the related lifetimes are discussed. Finally, we show that the coupling of different states at one level of complexity to some common decay channels at the next level, may produce interference-like patterns in the nuclear response. This quantum effect leads to a new type of fluctuations with a typical width related to the level spacing.

34 Latex pages including 6 figures (submitted to Phys. Rev. C)

References in corpus (5)

• A Simple Mode on a Highly Excited Background: Collective Strength and Damping in the Continuum
• Finite Temperature Nuclear Response in Extended Random-Phase Approximation
• Interfering Doorway States and Giant Resonances. I: Resonance Spectrum and Multipole Strengths
• Interfering Doorway States and Giant Resonances. II: Transition Strengths
• Scaling Analysis of Fluctuating Strength Function

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