Skip to main content
Seminar | Physics

Fundamental Symmetry Tests using Trapped Atoms and Ions

PHY Seminar

Abstract: Nuclear decay has a long-standing history of shaping and testing the standard model of particle physics, and it continues to this day with elegant, ultraprecise low-energy nuclear measurements. Experiments observing the angular correlations among the electron, neutrino, and recoil momenta following the decay of (un)polarized nuclei can be used to search for exotic currents contributing to the dominant V−A structure of the weak interaction. Precision measurements of the correlation parameters to <0.1% would be sensitive to (or meaningfully constrain) new physics, complementing other searches at large-scale facilities such as the Large Hadron Collier.

Ion and atom traps provide an ideal source of very cold, short-lived radioactive nuclei in an extremely clean and open environment. As such, they are invaluable tools for precision measurements of  beta decay parameters. This talk will focus on two such efforts. The TAMUTRAP facility at the Cyclotron Institute, Texas A&M University, will use an upgrade to the recently commissioned cylindrical Penning trap — already the world’s largest with an inner diameter of 90 mm — to search for scalar currents via the correlation in the delayed proton decay of nuclei. The other effort, based at TRIUMF in Vancouver, Canada, uses neutral atom-trapping techniques with optical pumping methods to highly polarize (>99%) 37K atoms. Recently, we determined the asymmetry parameter to 0.3% precision, which is comparable with or better than any other nuclear measurement, including the neutron.