Elastic and inelastic scattering of 12 C on 64 Zn at energies near the Coulomb barrier

Abstract

Background: The S˜ao Paulo Optical Model Protocol (SP-OMP) has been developed [1, 2] withthe aim of establishing a common background to describe stable tightly and weakly bound nucleireactions. This protocol consists of applying four optical model (OM) variants, based on the secondversion of the double folding (DF) S˜ao Paulo potential (SPP2) [3], and the respective optical potentials(OP), to reproduce experimental nuclear reaction data. The protocol includes a heat mapthat defines the correlation between real and imaginary OP strengths, their uncertainties, and thesensitivity of the data to them. The OP is applied to microscopic coupled channel (CC) calculations.Purpose: The current work presents new experimental data for the elastic and inelastic scatteringangular distributions of 12C+64Zn, at bombarding energies around the Coulomb barrier (VB ≈ 30MeV). Data were obtained at three bombarding energies: Elab = 29.9, 35.8 and 40.0 MeV. Weperform and present the SP-OMP analysis and CC calculations.Method: From the SP-OMP analysis, we determine the best-fit OPs. The OPs are then appliedto the CC calculations. The theoretical OM analysis and CC calculations are compared to theexperimental elastic and inelastic scattering angular distributions of 12C+64Zn.Results: The calculations provide an overall description of the data. The SP-OMP effectivelydescribes the elastic scattering cross sections of 12C+64Zn. The CC calculations corroborate theOM analysis, highlighting the main importance of taking into account the excited states of the 64Zntarget. In addition, we study the importance of coupling the first excited state of the 12C projectile,which shows to play an important role as the bombarding energy increases.Conclusion: The application of SP-OMP analysis combined with microscopic CC calculationsallows for a better and complementary understanding of the dynamics of 12C nuclear reactions asa function of the bombarding energy. The results should also contribute to further discriminatebetween reactions with tightly and weakly bound stable nuclei.