Large-scale shell-model calculations of nuclear Schiff moments of 129Xe and 199Hg
Abstract
The theoretical uncertainty in the nuclear Schiff moment is an obstacle to set constraints on CP violation beyond the standard model from experimental upper bounds on atomic electric dipole moments. We perform large-scale shell-model calculations of the 129Xe and 199Hg nuclei with realistic effective interactions. To estimate the Schiff moments caused by the P , T -odd π NN interaction perturbatively, we employ the one-particle one-hole approximation to the intermediate states. The Schiff moments of 129Xe and 199Hg are reduced due to the configuration mixing by 10 \% from the evaluation of the independent particle model. On the other hand, the reduction is more significant in mean-field based calculations and shell-model calculations with a drastic truncation. In order to resolve the discrepancy in the Schiff moment of 199Hg among several nuclear models, we survey low-energy nuclear structure. The large-scale shell-model calculations reveal that the Schiff moment of 199Hg is considerably quenched in the second 1 2 - state.