LLI and Solid State electron edm searches

Amherst College, Amherst MA

Investigators

Abstract

This experimental research program focuses on the continuation of an experiment to test Local Lorentz Invariance (LLI) and CPT (charge conjugation parity time) invariance. LLI, one of the fundamental postulates of the theory of relativity, is the notion that the laws of physics are the same in all locally inertial frames. While it is known that an experiment may give a different result if one changes the charge on a particle or the parity of the system or the direction of time, if changes are made in all three at the same time, then CPT invariance predicts that nothing may change. To date there is no evidence to indicate that this is not the case. To get at the results the group compares the relative precession frequencies of mercury and cesium magnetometers as a function of the orientation of an applied magnetic field with respect to the fixed stars. An earlier version of this experiment established the best limits on several possible violations of these symmetries. In the interim the experiment has been completely rebuilt, and the group expects to achieve a factor of 100 improvement in the experimental precision. At this level the experiment should provide the most stringent test of several possible mechanisms for violating LLI and CPT. The broader impact of the project involves a particularly strong undergraduate program that has successfully trained a number of future scientists and may be expected to continue to do so.