Superstatistical random-matrix-theory approach to transition intensities in mixed systems

Phys Rev E Stat Nonlin Soft Matter Phys. 2006 May;73(5 Pt 2):056119. doi: 10.1103/PhysRevE.73.056119. Epub 2006 May 19.

Abstract

We study the fluctuation properties of transition intensities applying a recently proposed generalization of the random matrix theory, which is based on Beck and Cohen's superstatistics. We obtain an analytic expression for the distribution of the reduced transition probabilities that applies to systems undergoing a transition out of chaos. The obtained distribution fits the results of a previous nuclear shell model calculations for some electromagnetic transitions that deviate from the Porter-Thomas distribution. It agrees with the experimental reduced transition probabilities for the nucleus better than the commonly used chi(2) distribution.