Atomic properties of Ra for a future EDM measurement*

Searches for non-zero permanent electric-dipole moments (EDM) of particles, atoms, and molecules represent remarkable opportunity to probe new physics beyond the standard model. The EDMs arise from the violations of both parity and time-reversal invariance. Atomic EDMs caused by the nuclear parity and time invariance violating effects are enhanced in certain diamagnetic atoms, such as $^{199}$Hg and $^{225}$Ra. For the latter, there is additional enhancement due to close states of opposite parity and the large nuclear charge Z [Dzuba et al., PRA 61, 062509 (2000)]. The search for EDM in $^{225}$Ra is presently underway [Holt et al., Nucl. Phys. A 844, 53c (2010)]. Few atomic properties of Ra are experimentally known. In this work, we carry out a systematic study of Ra atomic properties of interest to the EDM search using recently developed relativistic \textit{ab initio} method [Safronova at. al, PRA 80, 012516 (2009)] that allows to accurately treat correlation corrections in atoms with a few valence electrons. This method combines the coupled-cluster method, that yielded excellent results for monovalent systems, with the configuration-interaction approach. We have calculated energy levels, electric-dipole matrix elements, lifetimes, hyperfine constants, and polarizabilities.