Investigating the alpha-clustering on the surface of $^{120}$Sn via ($p$,$p\alpha$) reaction and the validity of the factorization approximation

TL;DR

This study uses the ($p$,$p extalpha$) reaction at 392 MeV to explore alpha-clustering on the surface of $^{120}$Sn and assesses the validity of the factorization approximation within the DWIA framework.

Contribution

It demonstrates the peripheral nature of the reaction and evaluates the impact of nuclear interior distortions on reaction observables, confirming the approximation's validity.

Findings

Reaction is highly peripheral due to strong alpha absorption.

Alpha clustering on the surface can be effectively probed.

Distortions in the interior do not affect reaction observables.

Abstract

The $^{120}$Sn($p$,$p\alpha$)$^{116}$Cd reaction at 392 MeV is investigated with the distorted wave impulse approximation (DWIA) framework. We show that this reaction is very peripheral mainly because of the strong absorption of $\alpha$ by the reaction residue $^{116}$Cd, and the $\alpha$-clustering on the nuclear surface can be probed clearly. We investigate also the validity of the so-called factorization approximation that has frequently been used so far. It is shown that the kinematics of $\alpha$ in the nuclear interior region is significantly affected by the distortion of $^{116}$Cd, but it has no effect on the reaction observables because of the strong absorption in that region.