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

Abstract

The proton-proton momentum correlation functions ($C_{pp}(q)$) for kinematically complete decay channels of ${}^{23}$Al $\to$ p + p + ${}^{21}$Na and ${}^{22}$Mg $\to$ 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.

6 pages, 4 figures; accepted by Phys. Rev. C