Francium spectroscopy: Towards a low energy test of the standard model

An atomic parity non-conservation measurement can test the predictions of the standard model for the electron-quark coupling constants. The measurements, performed at very low energies compared to the Z⁰ pole, can be sensitive to physics beyond the standard model. Francium, the heaviest alkali, is a viable candidate for atomic parity violation measurements. The extraction of weak interaction parameters requires a detailed knowledge of the electronic wavefunctions of the atom. Measurements of atomic properties of francium provide data for careful comparisons with ab initio calculations of its atomic structure. The spectroscopy, including energy level location and atomic lifetimes, is carried out using the recently developed techniques of laser cooling and trapping of atoms