Proton-proton correlations in distinguishing the two-proton emission mechanism of $^{23}$Al and $^{22}$Mg

TL;DR

This study measures proton-proton correlations in the decay of $^{23}$Al and $^{22}$Mg to differentiate their two-proton emission mechanisms, revealing sequential versus simultaneous emission processes.

Contribution

It introduces a method to distinguish two-proton emission mechanisms using proton-proton correlation functions and source size analysis.

Findings

$^{23}$Al mainly exhibits sequential two-proton emission.

$^{22}$Mg predominantly undergoes three-body simultaneous emission.

Correlation data effectively differentiate emission mechanisms.

Abstract

The proton-proton momentum correlation functions ($C_{pp}(q)$) for kinematically complete decay channels of $^{23}$Al $\rightarrow$ p + p + $^{21}$Na and $^{22}$Mg $\rightarrow$ p + p + $^{20}$Ne have been measured at the RIKEN RI Beam Factory. From the very different correlation strength of $C_{pp}(q)$ for $^{23}$Al and $^{22}$Mg, the source size and emission time information were extracted from the $C_{pp}(q)$ data by assuming a Gaussian source profile in the correlation function calculation code (CRAB). The results indicated that the mechanism of two-proton emission from $^{23}$Al was mainly sequential emission, while that of $^{22}$Mg was mainly three-body simultaneous emission. By combining our earlier results of the two-proton relative momentum and the opening angle, it is pointed out that the mechanism of two-proton emission could be distinguished clearly.