Parity-nonconserving interaction-induced light shifts in the $$\bf{7S}_{1/2}$$ 7 S 1 / 2 – $$\bf{6D}_{3/2}$$ 6 D 3 / 2 transition of the ultracold $${^{210}\bf{Fr}}$$ 210 Fr atoms to probe new physics beyond the standard model

We present an experimental technique to measure light shifts due to the nuclear spin independent (NSI) parity-nonconserving (PNC) interaction in the $$7S_{1/2}$$ – $$6D_{3/2}$$ transition in ultracold $${^{210}\mathrm{Fr}}$$ atoms. The approach we propose is similar to the one by Fortson (Phys Rev Lett 70:2383, 10) to measure the PNC-induced light shift which arises from the interference of parity nonconserving electric dipole transition and electric quadrupole transition amplitudes. Its major advantage is that it can treat more than $$10^4$$ ultracold $${^{210}\mathrm{Fr}}$$ atoms to enhance the shot noise limit. A relativistic coupled-cluster method has been employed to calculate the electric dipole transition amplitudes arising from the PNC interaction. Based on these calculations, we have evaluated the PNC-induced light shifts for transitions between the hyperfine levels of the $$7S_{1/2}$$ and $$6D_{3/2}$$ states and suitable transitions are identified for carrying out PNC measurements. It is possible in principle to probe new physics beyond the standard model with our proposed experimental scheme.