Fusion of $^{6}$Li with $^{159}$Tb} at near barrier energies

TL;DR

This study measures fusion cross sections for $^{6}$Li+$^{159}$Tb near the Coulomb barrier, revealing suppression of complete fusion at above-barrier energies and correlations with projectile alpha-separation energies, highlighting transfer and incomplete fusion processes.

Contribution

First detailed measurement of fusion cross sections for $^{6}$Li+$^{159}$Tb near the Coulomb barrier, analyzing suppression and transfer mechanisms compared to other boron isotopes.

Findings

Complete fusion is suppressed by ~34% at above-barrier energies.

Suppression correlates with projectile alpha-separation energies.

Transfer and incomplete fusion contribute differently at various energies.

Abstract

Complete and incomplete fusion cross sections for $^{6}$Li+$^{159}$Tb have been measured at energies around the Coulomb barrier by the $\gamma$-ray method. The measurements show that the complete fusion cross sections at above-barrier energies are suppressed by $\sim$34% compared to the coupled channels calculations. A comparison of the complete fusion cross sections at above-barrier energies with the existing data of $^{11,10}$B+$^{159}$Tb and $^{7}$Li+$^{159}$Tb shows that the extent of suppression is correlated with the $\alpha$-separation energies of the projectiles. It has been argued that the Dy isotopes produced in the reaction $^{6}$Li+$^{159}$Tb, at below-barrier energies are primarily due to the $d$-transfer to unbound states of $^{159}$Tb, while both transfer and incomplete fusion processes contribute at above-barrier energies.