$\mathcal{P},\mathcal{T}$-Violating and Magnetic Hyperfine Interactions in Atomic Thallium

Abstract

We present state-of-the-art configuration interaction and coupled cluster calculations of the electron electric dipole moment, the nucleon-electron scalar-pseudoscalar, and the magnetic hyperfine interaction constants ($\hat{I}{\pm }_{d_e},\hat{I}{\pm }_{C_S},A_{||}$, respectively) for the thallium atomic ground state ${}^2{P}_{1/2}$. Our present best values are $\hat{I}{\pm }_{d_e}=-559\pm 28$, $\hat{I}{\pm }_{C_S}=6.77\pm 0.34$ $[10^{-18}e$ cm$]$, and $A_{||}=21172\pm 1059$ [MHz]. These findings lead to a significant reduction of the theoretical uncertainties for $\mathcal{P},\mathcal{T}$-odd interaction constants but not to stronger constraints on the electron electric dipole moment, $d_e$, or the nucleon-electron scalar-pseudoscalar coupling constant, $C_S$.

13 pages, 2 figures