Theoretical studies of the long lifetimes of the 6 d D 3 / 2 , 5 / 2 2 states in Fr: Implications for parity-nonconservation measurements

摘要: Lifetimes of the $6d^{2}D_{3/2}$ and $6d^{2}D_{5/2}$ states in Fr are determined from calculations radiative transition amplitudes allowed electric dipole $(E1)$ forbidden quadrupole $(E2)$ magnetic $(M1)$ channels which were performed using second-order many-body perturbation theory coupled-cluster method at different levels approximations relativistic framework. The values obtained for these two quantities 540(10) 1704(32) ns, respectively. These relatively long lifetimes large parity-non-conserving $7s^{2}S_{1/2}\ensuremath{\rightarrow}6d^{2}D_{3/2,5/2}$ transitions strongly favor as a leading candidate measurement parity nonconservation arising neutral-current weak interaction nuclear anapole moment. In another important application, $6D$ can be used efficiently resonance ionization spectroscopic techniques to carry out precise measurements properties higher excited due states.