EQuAL Seminar: Haoran Li

"Probing Beyond Standard Model Physics with Radium-Based Molecular Ions"

Spectroscopy with radium-based molecular ions offers enhanced sensitivity for probing fundamental physics. Working toward this goal, a robust atomic source for short-lived radium atoms was realized with an effusive oven containing the parent species, thorium.

We trapped and laser cooled Ra (I = 0, 3.6-day half-life) and Ra (I = 1/2, 15-day half-life) ions with the atomic source developed. We performed spectroscopy measurements of properties of the low-lying states of radium ions that will facilitate future work with radium ions. These include hyperfine splitting measurements of the S , D 3 / 2 ,and P states of Ra , measurements of the energies of the four lowest excited states of Ra , and lifetime measurements of the metastable D and D 3 / 2 states of the radium ions with 224 R+a . We have also synthesized radium-based molecular ions in a room temperature trap and are working towards a molecular ion experiment in a cryogenic environment.