Transition from direct to sequential two-proton decay in $s$-$d$ shell nuclei

Transitions among different mechanisms of two-proton decay are studied in general. The introduced improved direct-decay model generalizes the semi-analytical models used before and provides flawless phenomenological description of three-body correlations in $2p$ decays. This is demonstrated by examples of the low-lying ${}^{16}$Ne state decays. Different forms of transition dynamic are shown to be highly probable beyond the proton dripline for the $s$-$d$ shell nuclei. It is demonstrated that transition dynamic of $2p$ emitters can provide means for extraction of a width of the ground-state resonance of a core+$p$ subsystem of the core+$2p$ system. Practical applicability of the method is demonstrated by properties of the ${}^{14}$F ground state derived from the $^{15}\mbox{Ne}\rightarrow ^{,13!!}\mbox{O}+2p$decaydataandofthe$^{29}$Cl ground state derived from the ${}^{30}Ar{\to }^{28\text{\hspace{0.17em}⁣}\text{\hspace{0.17em}⁣}}S+2p$ decay data.