Isotope-shift spectroscopy of the S0 1 → P1 3 and S0 1 → P0 3 transitions in strontium

Abstract

Isotope-shift spectroscopy with narrow optical transitions provides a benchmark for atomic structure calculations and has also been proposed as a way to constrain theories predicting physics beyond the standard model. Here we measure frequency shifts of the S01→P13 and S01→P03 transitions between Sr84,Sr86, and Sr87, relative to Sr88. Using the isotope-shift measurements of the two transitions, a King plot analysis is performed, revealing a nonlinearity in the measured values.