Sub-barrier enhancement of fusion as compared to a microscopic method in 18O+12C

TL;DR

This study measures fusion cross-sections at sub-barrier energies for 18O+12C and compares experimental results with advanced microscopic calculations, revealing larger tunneling probabilities than predicted.

Contribution

It provides new experimental data at sub-barrier energies and incorporates pairing effects into DC-TDHF calculations, highlighting discrepancies with theoretical models.

Findings

Experimental fusion cross-sections decrease less rapidly than theory predicts.

Observed larger tunneling probabilities at low energies.

Indicates the need for refined models with narrower fusion barriers.

Abstract

Measurement of the energy dependence of the fusion cross-sec on at sub-barrier energies provides an important test for theoretical models of fusion. To extend the measurement of fusion cross-sections in the sub-barrier domain for the 18O+12C system. Use the new experimental data to confront microscopic calculations of fusion. Evaporation residues produced in fusion of 18O ions with 12C target nuclei were detected with good geometric efficiency and identified by measuring their energy and time-of-flight. Theoretical calculations with a density constrained time dependent Hartree-Fock (DC-TDHF) theory include for the first time the effect of pairing on the fusion cross-section. Comparison of the measured fusion excitation function with the predictions of the DC-TDHF calculations reveal that the experimental data exhibits a smaller decrease in cross-section with decreasing energy than is theoretically predicted. The larger cross-sections observed at the lowest energies measured indicate a larger tunneling probability for the fusion process. This larger probability can be associated with a smaller, narrower fusion barrier than presently included in the theoretical calculations.