Transition-State Theory for Fission Angular Distributions: A Flexible-Rotor Model

Current studies of heavy-ion reactions make extensive use of fission-fragment angular distributions to probe the limits of statistical equilibrium. The ''standard'' theory was derived for a rigid-rotor, transition-state nucleus. Here a more complete theory is developed by inclusion of the dependence of transition-state shape on orientation of the symmetry axis. It is concluded that even this improved application of the liquid drop model cannot give an adequate prediction of the Z/sup 2//A dependence of fission-fragment anisotropies.