Nucleus-nucleus potentials in the scattering of tightly and weakly bound systems

TL;DR

This paper investigates nucleus-nucleus potentials in fusion and elastic scattering reactions involving both tightly and loosely bound systems, highlighting the need for different modeling approaches for direct reactions and fusion.

Contribution

It compares coupled-channel and single-channel models for different nuclear reactions, revealing the necessity of distinct approximations for accurate modeling.

Findings

Different absorption terms are needed for fusion and elastic scattering.

Coupled-channel calculations provide insights into reaction mechanisms.

Modeling approaches should be tailored for specific reaction types.

Abstract

\begin{description} \item[Background] Fusion reactions play an important role in nucleosynthesis and in applications to society. Yet they remain challenging to model. \item[Purpose] In this work, we investigate the features of the nucleus-nucleus potentials that describe fusion cross sections and compare with those needed for realistic calculations of elastic scattering and other direct-reaction cross sections. \item[Method] We perform coupled-channel calculations for studying elastic and fusion reactions around the Coulomb barrier with a tightly bound projectile ($^{16}$O+$^{144}$Sm). We also perform Continuum Discretized Coupled Channel calculations to study elastic ($^{8}$B+$^{58}$Ni) and fusion ($^{6}$Li+$^{198}$Pt) of loosely bound projectiles in the same energy regime. \item[Results] We contrast the coupled-channel results with those obtained in a single-channel solution with different assumptions for polarization potentials to shed light on the relevant absorption terms required for the two different reaction channels. \item[Conclusions] Our results suggest that different approximations may be required for modeling direct processes and for modeling fusion reactions. \end{description}