Systematics of capture and fusion dynamics in heavy-ion collisions

TL;DR

This paper presents an empirical coupled-channel model with a barrier distribution to systematically analyze capture excitation functions in heavy-ion collisions, effectively incorporating couplings and neutron transfer effects.

Contribution

It introduces empirical formulas for barrier distribution parameters, enabling accurate predictions of capture cross sections across many reaction systems.

Findings

Empirical formulas accurately predict capture cross sections near the Coulomb barrier.

Model effectively incorporates coupling effects and neutron transfer channels.

Results align well with experimental data for 220 reaction systems.

Abstract

We perform a systematic study of capture excitation functions by using an empirical coupled-channel model. In this model, a barrier distribution is used to take effectively into account the effects of couplings between the relative motion and intrinsic degrees of freedom. The shape of the barrier distribution is of an asymmetric Gaussian form. The effect of neutron transfer channels is also included in the barrier distribution. Based on the interaction potential between the projectile and the target, empirical formulas are proposed to determine the parameters of the barrier distribution. Theoretical estimates for barrier distributions and calculated capture cross sections together with experimental cross sections of 220 reaction systems with $182 \leqslant Z_{\rm P}Z_{\rm T} \leqslant 1640$ are tabulated. The results show that our empirical formulas work quite well in the energy region around the Coulomb barrier. This model can provide prediction of capture cross sections for the synthesis of superheavy nuclei as well as valuable information on capture and fusion dynamics.