title: Spectroscopy with random and displaced random ensembles.
abstract: Because of the time reversal invariance of the angular momentum operator J2, the average energies and variances at fixed J for random two-body Hamiltonians exhibit odd-even- J staggering that may be especially strong for J = 0. It is shown that upon ensemble averaging over random runs, this behavior is reflected in the yrast states. Displaced (attractive) random ensembles lead to rotational spectra with strongly enhanced B(E2) transitions for a certain class of model spaces. It is explained how to generalize these results to other forms of collectivity.
authors.affiliation: IRES, Bâtiment 27, IN2P3-CNRS/Université Louis Pasteur BP 28, F-67037 Strasbourg Cedex 2, France.
authors.forename: V
authors.initials: V
authors.lastname: Velázquez
authors.forename: A P
authors.initials: AP
authors.lastname: Zuker