The dominance of matter over anti-matter cannot be explained by the standard model of physics. Additional symmetry violation can explain the matter/anti-matter asymmetry and would also give rise to permanent electric dipole moments (EDMs) in fundamental and composite particles that are greater than the standard model prediction. The 225Ra (t1/2=15d, I=1/2) atom is a particularly attractive system for an EDM search because its large nuclear octupole deformation, closely spaced ground-state parity doublet, and large atomic mass make 225Ra uniquely sensitive to symmetry-violating interactions in the nuclear medium that give rise to an EDM. We have developed an experiment to measure the EDM of 225Ra and demonstrated the first “proof-of-principle” measurement, giving an upper limit at the 10-22 e-cm level. Future upgrades to our experiment have the potential to improve our EDM sensitivity by several orders of magnitude and test fundamental symmetries at an unprecedented level.
Argonne Physics Division Seminar Schedule