Model for compound nucleus formation in various heavy-ion systems

TL;DR

This paper presents a detailed statistical model for calculating compound nucleus formation cross sections in various heavy-ion systems, considering competing barriers and angular momentum effects, with results aligning well with experimental data.

Contribution

It introduces a unified approach to model compound nucleus formation across light to super-heavy systems, accounting for barrier competition and angular momentum limitations.

Findings

The model accurately predicts cross sections for different systems.

Compound nucleus formation is suppressed when quasi-elastic barriers are lower.

Results agree with experimental data across multiple systems.

Abstract

The statistical model for the calculation of the compound nucleus formation cross section and the probability of compound nucleus formation in heavy-ion collisions is discussed in detail. The light, heavy, and super-heavy nucleus-nucleus systems are considered in this model in the framework of one approach. It is shown that the compound nucleus is formed in competition between passing through the compound-nucleus formation barrier and the quasi-elastic barrier. The compound-nucleus formation barrier is the barrier separating the system of contacting incident nuclei and the spherical or near-spherical ground state of the compound nucleus. The quasi-elastic barrier is the barrier between the contacting and well-separated deformed ions. It is shown that the compound nucleus formation cross-section is suppressed when the quasi-elastic barrier is lower than the compound nucleus formation barrier. The critical value of angular momentum, which limits the compound nucleus formation cross-section values for light and medium ion-ion systems at over-barrier collision energies, is discussed in the model. The suppression of the compound nucleus formation cross-section even at small partial waves for very heavy ion-ion systems is obtained in the model. The values of the capture and compound nucleus formation cross-sections calculated for various light, heavy, and super-heavy nucleus-nucleus systems as well as the probability of the compound nucleus formation for super-heavy nuclei are well agreed with the available experimental data.