Exploring contributions from incomplete fusion in $^{6,7}$Li+$^{209}$Bi and $^{6,7}$Li+$^{198}$Pt reactions

TL;DR

This study models and analyzes the contributions of incomplete fusion processes in reactions involving weakly bound $^{6,7}$Li nuclei with $^{209}$Bi and $^{198}$Pt, revealing the dominance of ICF at sub-barrier energies and validating the model with experimental data.

Contribution

The paper introduces a breakup absorption model using CDCC to accurately describe ICF, CF, and TF cross-sections in weakly bound nuclear reactions, aligning well with experimental observations.

Findings

ICF cross-sections for deuteron and triton are comparable or dominant depending on the projectile.

ICF becomes more prominent than CF at energies below the Coulomb barrier.

Non-capture breakup is more significant than ICF at sub-barrier energies.

Abstract

We use the breakup absorption model to simultaneously describe the measured cross-sections of the Complete fusion (CF), Incomplete fusion (ICF), and Total fusion (TF) in nuclear reactions induced by weakly bound nuclei $^{6,7}$Li on $^{209}$Bi and $^{198}$Pt targets. The absorption cross-sections are calculated using the Continuum Discretized Coupled Channels (CDCC) method with different choices of short range imaginary potentials to get the ICF, CF and TF cross-sections. It is observed that the cross-sections for deuteron-ICF/deuteron-capture are of similar magnitude as the $\alpha$-ICF/$\alpha$-capture, in case of $^{6}$Li projectile, while the cross-sections for triton-ICF/triton-capture is more dominant than $\alpha$-ICF/$\alpha$-capture in case of $^{7}$Li projectile. Both these observations are also corroborated by the experimental data. The ratio of ICF to TF cross-sections, which defines the value of fusion suppression factor is found to be in agreement with the data available from the literature. The cross-section ratio of CF/TF and ICF/TF show opposite behavior, the former decreases while the latter increases as the energy is lowered, which shows the dominance of ICF at below barrier energies. We have also studied the correlation of the ICF cross-sections with the non-capture breakup (NCBU) cross-sections as a function of energy, which shows that the NCBU is more significant than ICF at below barrier energies.