The role of relativistic many-body theory in probing new physics beyond the standard model via the electric dipole moments of diamagnetic atoms

摘要

The observation of electric dipole moments (EDMs) in atomic systems due toparity and time-reversal violating (P,T-odd) interactions can probe new physicsbeyond the standard model and also provide insights into the matter-antimatterasymmetry in the Universe. The EDMs of open-shell atomic systems are sensitiveto the electron EDM and the P,T-odd scalar-pseudoscalar (S-PS) semi-leptonicinteraction, but the dominant contributions to the EDMs of diamagnetic atomscome from the hadronic and tensor-pseudotensor (T-PT) semi-leptonicinteractions. Several diamagnetic atoms like $^{129}$Xe, $^{171}$Yb,$^{199}$Hg, $^{223}$Rn, and $^{225}$Ra are candidates for the experimentalsearch for the possible existence of EDMs, and among these $^{199}$Hg hasyielded the lowest limit till date. The T or CP violating coupling constants ofthe aforementioned interactions can be extracted from these measurements bycombining with atomic and nuclear calculations. In this work, we report thecalculations of the EDMs of the above atoms by including both theelectromagnetic and P,T-odd violating interactions simultaneously. Thesecalculations are performed by employing relativistic many-body methods based onthe random phase approximation (RPA) and the singles and doublescoupled-cluster (CCSD) method starting with the Dirac-Hartree-Fock (DHF) wavefunction in both cases. The differences in the results from both the methodsshed light on the importance of the non-core-polarization electron correlationeffects that are accounted for by the CCSD method. We also determine electricdipole polarizabilities of these atoms, which have computational similaritieswith EDMs and compare them with the available experimental and othertheoretical results to assess the accuracy of our calculations.