An One Dimensional Adiabatic Model for Fusion Involving Loosely Bound and Halo Nuclei with Heavy Targets

TL;DR

This paper introduces a one-dimensional adiabatic model for fusion involving loosely bound and halo nuclei with heavy targets, explaining fusion cross sections at near and sub-barrier energies without explicit breakup coupling.

Contribution

The paper presents a novel adiabatic model that successfully explains fusion cross sections for certain loosely bound and halo nuclei systems, differing from traditional models that require breakup coupling.

Findings

Model explains fusion cross sections for $^{6}Li+^{198}Pt$ and $^{8}He+^{197}Au.

The adiabatic approach does not work for stable $^{4}He+^{197}Au$ system.

Neutron flow and neck formation at larger distances modify the potential.

Abstract

An one dimensional adiabatic model has been proposed for fusion of loosely bound and halo light nuclei with various heavy targets. It is shown that fusion cross sections at near and sub-barrier energies can be explained using a simple WKB tunneling through an adiabatic barrier without invoking breakup coupling explicitly. The model has been applied successfully to explain fusion cross sections for several systems including recently measured $^{6}Li+^{198}Pt$ system (Phy. Rev. Lett. 103, 232702, 2009) where data exists well above and below the barrier and $^{8}He+^{197}Au$ system (Phy. Rev. Lett. 103, 232701, 2009) where $^{8}He$ is highly neutron rich. Interestingly, the fusion of stable $^{4}He+^{197}Au$ system can not be explained on the basis of this adiabatic model as it requires normal tunneling through the sudden barrier. The requirement of adiabatic potential for the loosely bound and halo nuclei is linked to the fact that for such systems neutron flow leading to neck formation is initiated at a larger distance which modifies the sudden potential.