Decay of ^203,204Pb^∗ Nuclei at Energies Across the Coulomb Barrier Using Cluster Emission Approach

Abstract

In reference to recent experimental data, the evaporation residue (ER) cross sections are estimated for the ^203,204Pb^∗ systems, formed via ^6,7Li+¹⁹⁷Au reactions, over a wide range of incident energies around the Coulomb barrier, using the dynamical cluster-decay model (DCM). A comparative analysis of different isotopes of Pb formed using stable beams is carried out considering various effects, such as excitation energy, angular momentum, and deformation, etc. The role of deformation is worked out by comparing the decay path for spherical and β₂ deformed fragmentations. The relative contribution of static β_2i(0) and dynamic β_2i(T) quadrupole deformations on the fragmentation path is studied. Further, the distribution of the average total kinetic energy among the binary decay fragments of ²⁰³Pb^∗ is estimated. The role of different nuclear proximity interactions leading to a wide spectrum of barrier characteristics is also explored for better understanding of the dynamics involved. The relative contribution of the temperature dependent shell corrections is analyzed in the ⁶Li+¹⁹⁷Au reaction. For both the systems (^203,204Pb^∗), the calculated evaporation residue cross sections find nice agreement with the reported experimental data. Also, the contribution of the fission decay mode for the ²⁰³Pb^∗ system is predicted over a range of incident energies. An experimental verification is called for the predicted fission cross sections and average total kinetic energy.