One-neutron transfer reaction and refractive effects in the 16O+ 16O system

Abstract

One-neutron transfer data of the 16O( 16O, 17O) 15O reaction have been measured for the p 1/2 ground state and p 3/2 excited hole state in 15O, at incident energies ranging from 250 to 1120 MeV. Some remnant of refraction (rainbow) pattern was observed for the ground state transition to 15O 1/2 − , whereas for the neutron hole state 15O ∗ 3/2 − at 6.176 MeV excitation energy the angular distributions show more or less an exponential fall-off. The data were analyzed using the full finite-range distorted wave Born approximation (DWBA). The DWBA description of the transfer data over the whole measured angular range was possible only, if the indirect term of the transition operator is properly included and the absorption in the exit channels is substantially increased, especially, for the 15O ∗ 3/2 − channel. The energy dependence of the transfer cross sections has been consistently described with two choices for the real part of the optical potential: the folding potential and the squared Woods–Saxon potential. The obtained spectroscopic factors, S(1/2 −)=1.8±0.3 and S(3/2 −)=4.0±0.5, are energy independent.