Three-body analysis reveals the significant contribution of minor $^{5}$He $s$-wave component in $^{6}$Li$(p,2p)^{5}$He cross section

TL;DR

This study uses a three-body model to analyze the $^{6}$Li($p$,$2p$)$^{5}$He reaction, highlighting the significant role of the minor $^{5}$He $s$-wave component in the reaction cross section.

Contribution

It demonstrates the importance of the $^{5}$He $s$-wave component in $^{6}$Li reactions using a three-body wave function and Gaussian expansion method.

Findings

The model reproduces experimental cross sections within 10% accuracy.

Both $p$- and $s$-wave states of $^{5}$He are crucial in the reaction.

The $s$-wave component is especially important at zero recoil-momentum.

Abstract

$^6$Li is usually treated as an $\alpha+p+n$ three-body system, and the validity of this picture is important for understanding $^6$Li reactions. The ($p$,$2p$) reaction is a powerful method to study the structure of valence nucleons in $^6$Li. Recently, the new experimental data of the $^{6}$Li($p$,$2p$)$^{5}$He reaction have been obtained and should be analyzed. We investigate the $^{6}$Li($p$,$2p$)$^{5}$He reaction using the $\alpha+p+n$ three-body wave function of $^6$Li and study the validity of this model. We calculate the $^6$Li wave function by using Gaussian expansion method, and the function is used to obtain the relative wave function between $p$ and $^5$He. We combine the relative wave function with the distorted wave impulse approximation. Our results reproduce the experimental data of the triple differential cross section within about 10\% difference in the absolute values, and contributions from both $p$- and $s$-wave states of $^5$He in $^6$Li are found to be important. We can qualitatively understand the $^{6}$Li($p$,$2p$)$^{5}$He reaction by describing $^6$Li with the three-body model. Contribution from the $s$-wave component is important in reproducing the experimental data in the zero recoil-momentum region.