${\cal{(P,T)}}$-Odd Tensor-Pseudotensor Interactions in atomic {$^{199}$Hg} and {$^{225}$Ra}

Abstract

Highly correlated pure {\it{ab initio}} relativistic configuration interaction theory is in the present paper applied to the calculation of the tensor-pseudotensor ${\cal{(P,T)}}$-violating nucleon-electron interaction constant in the electronic ground states of atomic mercury and radium. The final best obtained results are $R_T$(Hg) = $-4.43$\, [$10^{-20}$ $\left<\sigma_N\right>$ $e$ cm] and $R_T$(Ra) = $-15.0$\, [$10^{-20}$ $\left<\sigma_N\right>$ $e$ cm]. The accuracy of the employed electronic-structure models are confirmed by determining the static electric dipole polarizability $\alpha_d$(Hg) = $35.7$ {\it{a.u.}} which is in accord with the experimental value to about $5$\%. $R_T$(Ra) will be useful for constraining (or obtaining) the ${\cal{(CP)}}$-violating parameter $C_T$ when combined with future measurements of the electric dipole moment of the radium atom.