RUI: Tests of Fundamenal Symmetries using Hg, Cs and GdIG

Amherst College, Amherst MA

Investigators

Abstract

This RUI award funds two projects at Amherst College. The first project is a continuation of an experiment to test Local Lorentz Invariance (LLI) and CPT invariance. LLI is the notion that the laws of physics are the same in all locally inertial frames. This is one of the fundamental postulates of the theory of Relativity. CPT is the product of the discrete symmetries charge conjugation, parity and time. No violation of either LLI or CPT has ever been observed. Much of our understanding of fundamental physics would have to be radically altered if a violation is observed. The experiment compares the relative precession frequencies of Hg and Cs magnetometers as a function of the orientation of an applied magnetic field with respect to the "fixed stars". The second project involves the investigation of the possibility of using a solid-state system (gadolinium iron garnet) to measure the electron electric-dipole moment (edm). Most particle physics models that go beyond the Standard Model (such as Supersymmetry) predict an electron edm very near the current experimental bound (about 10-27 e-cm). Thus far, all attempts to find the electron edm are consistent with zero. Present estimates of the proposed experiment's sensitivity suggest that it should be possible to detect an electron edm as small as 10-29 e-cm. If an electron edm is observed, it would constitute a violation of time-reversal symmetry and be evidence for new physics beyond the Standard Model. The broader impacts of the program relate to important implications for particle physics, but also provide a broad and flexible training for future scientists, especially at the undergraduate level.