Indications of a shallow potential in $^{48}$Ca+$^{96}$Zr fusion reactions

TL;DR

This paper demonstrates that a shallow potential pocket in the entrance channel explains the fusion behavior of $^{48}$Ca+$^{96}$Zr, aligning theoretical models with experimental data and predicting hindrance effects in similar systems.

Contribution

It introduces a shallow potential pocket in coupled-channels calculations to accurately reproduce fusion data for $^{48}$Ca+$^{96}$Zr, resolving previous discrepancies.

Findings

Reproduces the observed $S$ factor maximum at low energy.

Accounts for high-energy fusion data with a short-ranged imaginary potential.

Predicts fusion hindrance effects in other Ca+Zr systems.

Abstract

Fusion data for $^{48}$Ca+$^{96}$Zr are analyzed by coupled-channels calculations. Puzzling features of a previous analysis are eliminated by applying a potential that has a shallow pocket in the entrance channel. Thus the observed $S$ factor for fusion, which develops a maximum at low energy, can be reproduced fairly well. The high-energy data can also be accounted for but that requires the use of a weak, short-ranged imaginary potential that absorbs the incoming flux near the location of the minimum of the potential pocket. Predictions of the fusion hindrance in other Ca+Zr systems are made and are compared with the systematics that has been developed previously.