Relativistic evaluation of the two-photon decay of the metastable 1s22s2p 3P0 state in berylliumlike ions with an effective-potential model

TitleRelativistic evaluation of the two-photon decay of the metastable 1s22s2p 3P0 state in berylliumlike ions with an effective-potential model
Publication TypeJournal Article
Year of Publication2016
AuthorsAmaro, Pedro, Fratini Filippo, Safari Laleh, Machado Jorge, Guerra Mauro, Indelicato Paul, and Santos Jose Paulo
JournalPhysical Review A
Volume93
Pagination032502-8
Date PublishedMar 07
AbstractThe two-photon $1{s}^{2}2s2p\phantom{\rule{0.16em}{0ex}}{}^{3}{P}_{0}\ensuremath{\rightarrow}1{s}^{2}{s}^{2}\phantom{\rule{0.16em}{0ex}}{}^{1}{S}_{0}$ transition in berylliumlike ions is investigated theoretically within a fully relativistic framework and a second-order perturbation theory. We focus our analysis on how electron correlation, as well as the negative-energy spectrum, can affect the forbidden $E1M1$ decay rate. For this purpose, we include the electronic correlation via an effective local potential and within a single-configuration-state model. Due to its experimental interest, evaluations of decay rates are performed for berylliumlike xenon and uranium. We find that the negative-energy contribution can be neglected at the present level of accuracy in the evaluation of the decay rate. On the other hand, if contributions of electronic correlation are not carefully taken into account, it may change the lifetime of the metastable state by up to 20%. By performing a fully relativistic $jj$-coupling calculation, we find a decrease of the decay rate by two orders of magnitude compared to nonrelativistic $LS$-coupling calculations, for the selected heavy ions.
URLhttp://link.aps.org/doi/10.1103/PhysRevA.93.032502
Short TitleJPS_Articles