Shell-model tests of the bimodal partial state densities in a 2 × 2 partitioned embedded random matrix ensemble

Abstract

The mixing of well-separated subspacesof an interacting many-particle system,such as a nucleus with active nucleons distributed in more than one major shell,can be studied usingpartitioned embedded ensembles of random matrices. The bimodalform of partial state densities (one-point functions) predictedearlier for a 2 × 2 partitioned embedded ensemble, whichmay be regarded as a model for the mixing of two well-separated degeneratesubspaces, is tested using nuclear shell-model calculations in the[(ds)6 ⊕ (ds)4 (f7/2)2]J=0,T=0 space. Thetheoretical forms predicted by the binary correlationapproximation theory are in good agreement with the shell-modelresults. This suggests that with suitable extensions it might be feasibleto use the binary correlation method to deal with severalinteracting subspaces involving multimodal distributions.PACS Nos.: 05.30.-d, 05.45.Mt, 24.60.Lz