ISOLDE Seminar

Cold, trapped radium-based molecular ions for probing new physics

by Mingyu Fan (Department of Physics, University of California, Santa Barbara)




Charge conjugation parity (CP) violation is at the heart of major unsolved problems in physics, including the matter-antimatter asymmetry of the Universe and the Strong CP problem. Heavy atoms and molecules provide the opportunity to probe CP symmetry by constraining the magnitude of time symmetry violating moments, such as the electron’s electric dipole moment, or the Schiff moment of nuclei. Such low energy searches for new physics may indict the presence of new high energy particles that may be directly detected in a high energy particle collider. Radium, the heaviest alkaline earth element, is one of the most sensitive probes to hadronic CP violation because in addition to its high mass it has an octupole deformed nucleus which provides a factor of 200x sensitivity enhancement compared to round nuclei. When the radium nucleus is incorporated in a molecule, the sensitivity to CP violation is further amplified by the molecule’s large electric field which may be easily controlled in the laboratory frame. In this talk, I will present our recent progress on the production and detection of radium-based molecular ions, and discuss planned precision measurements using these radioactive molecules.