Progress toward improved limits on charge-parity violation using octupole-deformed Radium atoms*

Tests of fundamental symmetries are a hot topic in physics as recent experiments have dramatically improved limits on charge-parity violation for the electron and current experiments anticipate additional sensitivity improvements. While the Standard Model provides allowances for higher-order symmetry violations, their effect is miniscule compared to current experimental limits. Beyond-Standard-Model (BSM) theories (e.g. supersymmetry) formulated to explain experimental observations, such as matter-antimatter asymmetry, naturally include additional symmetry violation. However, null results from previous symmetry violation experiments already limit the validity of BSM theories and new experimental limits will further restrict these theoretical extensions to the Standard Model. Within this class of experiments, Radium is an interesting candidate because its octupole-deformed nucleus enhances experimental sensitivity to symmetry-violating effects within the nucleus. Specifically, ²²⁵Ra is an ideal species for observing the nuclear Schiff moment arising from CP-violating interactions within the nucleus. Reported here are multiple recent experimental advances aimed at improving the sensitivity of the Radium electric dipole moment experiment to bring it to the frontier of searching for beyond-Standard-Model physics.