Two-proton radioactivity from excited states within the generalized liquid drop model

摘要: Unlike ground-state two-proton ($2p$) radioactivity, excited-state $2p$ emission is typically characterized by high decay energy and angular momentum, making it an important probe for studying the nuclear structure of extremely proton-rich nuclei. However, describing excited-state $2p$ radioactivity half-lives also poses a challenge to theoretical models. To examine whether the generalized liquid drop model (GLDM) with the improved proximity energy (Prox. 77-Set 13), optimized using ground-state $2p$ radioactivity experimental data, can be extended to describe excited-state $2p$ radioactivity, this work calculates the half-lives for $^{14}$O$^{*}$, $^{17}$Ne$^{*}$, $^{18}$Ne$^{*}$, $^{29}$S$^{*}$, and $^{94}$Ag$^{*}$. The present calculations are compared with experimental data and calculations obtained from the effective liquid drop model (ELDM), the unified fission model (UFM), and the Coulomb and proximity potential model (CPPM). The results calculated by this work are in good agreement with both the experimental data and the results of other theoretical models, validating the applicability of the GLDM with improved proximity energy for describing excited-state $2p$ radioactivity. This work also systematically investigates the dependence of excited-state $2p$ radioactivity half-life on decay energy and angular momentum, which will shed new light on the properties of exotic proton-rich nuclei.