Sub-barrier fusion excitation for the system $^7$Li+$^{28}$Si

TL;DR

This study measures sub-barrier fusion excitation functions for the $^7$Li + $^{28}$Si system, revealing significant enhancement over theoretical models and highlighting the role of nuclear coupling effects.

Contribution

First measurement of sub-barrier fusion for $^7$Li + $^{28}$Si using gamma-ray detection, showing notable enhancement and the impact of coupling effects.

Findings

Fusion enhancement by a factor of two below the barrier.

Coupling to the target's 2+ rotational state improves model fit.

Remaining enhancement of 25-40% suggests additional effects.

Abstract

The sub-barrier fusion excitation functions are measured for the first time for the system $^7$Li +$^{28}$Si by the characteristic $\gamma$-ray method in the energy range $E_{lab}$= 7-11.5 MeV. The results show an enhancement, below the barrier, by about a factor of two when compared with the one-dimensional barrier penetration (1D BPM) model. Introduction of coupling with the rotational 2$^{+}$ state (1.779MeV) of the target improves the fit somewhat, but still an enhancement of about 25-40% remains.