Coupled-channel description of resonant structures in the ¹⁶O + ²⁰Ne system

Gross resonant structures observed in elastic scattering, inelastic scattering and the total reaction cross section for the ¹⁶O + ²⁰Ne system have been studied successfully using a coupled-channel approach, within a symmetric rotor model, with the diagonal potential modified to include both a parity-dependent real interaction and an angular-momentum (J)-dependent absorptive term. It is shown that the inclusion of both these terms is essential for the prediction of the four correlated gross structures observed in the energy range 23 MeV ≦ E_c.m ≦ 38 MeV for both elastic and inelastic scattering excitation functions at backward angles. Each of the gross structures is modelled as a doublet of even-parity plus odd-parity resonances, which arise as a consequence of the parity-dependent interaction and which are enhanced by the J-dependent absorptive form. The elastic and inelastic scattering angular distributions at a number of energies are also well described. It is demonstrated that the inclusion of strong coupling overcomes a number of inadequacies noted in previous optical-model calculations for the ¹⁶O + ²⁰Ne system. The total angular momenta of the resonant states obtained in the coupled-channel calculations are higher than those extracted from calculations which ignore coupling.