[1] Budker’s team observed the largest parity violation in atoms using ytterbium isotopes in 2009, achieving a signal 100 times stronger than previous cesium-based experiments.
[4] By probing forbidden transitions in ytterbium-174, they revealed how the weak nuclear force mixes atomic states of opposite parity, enabling precise measurements of neutron distributions in nuclei.
[5] This work provided the first experimental constraints on the hypothetical “neutron skin” in heavy nuclei[6] and laid groundwork for testing anapole moments predicted by the Standard Model.
In 2010, Budker’s group conducted the most sensitive low-energy test of the spin-statistics theorem, confirming photons obey Bose-Einstein statistics with <1 violation per 100 billion interactions.
[7] Using barium atoms and counter-propagating lasers, they searched for forbidden two-photon transitions that would violate quantum statistics, achieving a 3,000-fold sensitivity improvement over prior work.