Application of relativistic coupled-cluster theory to atomic parity non-conservation

Despite the remarkable success of the standard model, it is widely believed that it is just an intermediate step in understanding the properties of the elementary particles in nature and the interactions between them. Studies of parity non-conservation in atomic systems based on non-accelerator methods have advanced over the years and they have now attained the maturity to test the standard model. The most accurate data from this approach comes from the 6s2S1/2→7s2S1/2 transition in cesium. An experiment on singly ionized barium has been proposed to carry out a further test of this kind independent of cesium. We discuss here the result of our ab initio calculation of the 6s2S1/2→5d2D3/2 parity non-conserving electric dipole transition amplitude in 137Ba+ based on a novel relativistic coupled-cluster theory. We also discuss a possible improvement of the existing cesium parity non-conservation calculations.