Precision Parity Violation in Light Atoms: New Windows on Dark Bosons and Fifth Forces

Potvliege (2024) used high-precision atomic spectroscopy to constrain new electron-proton interactions, but didn’t exploit parity-violating observables. Choi et al. (2018) demonstrated new coherent-control techniques for atomic parity violation (PNC) in cesium. I propose adapting these state-of-the-art PNC measurement techniques to light atoms (H, D, He), where theoretical calculations are exceptionally clean and new physics signals (from, e.g., dark Z' bosons or light CP-even scalars as discussed by Barducci et al. 2025) could be more transparently interpreted. This would allow us to probe parameter space for light mediators and fifth forces with much smaller theoretical uncertainties than in heavy atoms. The approach bridges modern atomic physics, precision measurement, and BSM phenomenology, promising cleaner BSM sensitivity than current heavy-atom PNC or purely spectroscopic methods.

References:

1. On the Atomki nuclear anomaly after the MEG-II result. D. Barducci, Davide Germani, M. Nardecchia, Stefano Scacco, C. Toni (2025). Journal of High Energy Physics.
2. Spectroscopy of light atoms and bounds on physics beyond the standard model. R. M. Potvliege (2024). New Journal of Physics.
3. Gain measurement scheme for precise determination of atomic parity violation through two-pathway coherent control. J. Choi, R. T. Sutherland, George Toh, A. Damitz, D. Elliott (2018).