Compound spreading widths for 209Bi analog resonances

The compound spreading widths (due to the Coulomb interaction) of 9/2⁺, 11/2⁺, 15/2⁻,1/2⁺, 7/2⁺, and 3/2⁺ analog resonances in Bi²⁰⁹ are calculated within the general framework of the de Toledo Piza-Kerman scheme by relegating the giant isovector monopole contributions to the continuum space. The work emphasizes the structure of the parent states and the coupling is via [H_c, T₋]. The widths are found to be of the order of 20 keV, which is considerably less than the observed experimental total widths of 200-300 keV. A background of (i) configuration states (6 including the antianalog state for each analog resonance) and (ii) complex levels (e.g., 33261 states for 9/2⁺ are considered. The one-body Coulomb interaction represented by a uniform sphere of charge is used for (i), while the two-body Coulomb force is expanded in multipoles for (ii). In (i) the dependence on the Coulomb radius and the nuclear spreading width are also studied. For all doorways the relative importance, number, density, strength, and compound-width contributions are investigated in great detail and the results are presented in tables and histograms. In addition to certain states of type (i) the most significant complex states are those based on the Pb²⁰⁸ giant dipole doorway resonance.