Disagreement between capture probabilities extracted from capture and quasi-elastic backscattering excitation functions

TL;DR

This paper compares capture probabilities from quasi-elastic backscattering and fusion data for certain heavy-ion reactions, finding significant discrepancies at sub-barrier energies that impact nuclear potential models.

Contribution

It reveals a systematic disagreement between capture probabilities derived from two different experimental methods at sub-barrier energies.

Findings

Probabilities from quasi-elastic data are larger than those from fusion data at sub-barrier energies.

The discrepancy explains differences in nuclear potential diffuseness obtained by the two methods.

Highlights the need to reconcile measurement techniques for accurate nuclear potential modeling.

Abstract

Experimental quasi-elastic backscattering and capture (fusion) excitation functions are usually used to extract the s-wave capture probabilities for the heavy-ion reactions. We investigated the $^{16}$O+$^{120}$Sn,$^{144}$Sm,$^{208}$Pb systems at energies near and below the corresponding Coulomb barriers and concluded that the probabilities extracted from quasi-elastic data are much larger than the ones extracted from fusion excitation functions at sub and deep-sub barrier energies. This seems to be a reasonable explanation for the known disagreement observed in literature for the nuclear potential diffuseness derived from both methods.