Precision isotope-shift spectroscopy for new physics searches and nuclear insights

Abstract

Shifts in the frequency of atomic spectral lines between different isotopes can be used to reveal subtle changes in the properties of nuclei. With the advent of ultra-high-precision optical spectroscopy, it is also possible to use these isotope shifts to probe physics beyond the standard model, specifically whether a fifth force exists. This Perspective outlines the progress and challenges of these studies and provides an outlook on future possibilities. This Perspective explores how the frequency shifts of atomic spectral lines between isotopes can be effective probes of physics beyond the standard model, when measured to high precision using optical spectroscopy.