Penning-Trap Signals for Lorentz and CPT Violation

Prospective signals for Lorentz and CPT violation are studied for Penning-trap experiments. The general effective field theory known as the Standard-Model Extension is used to identify observable signals in measurements of anomaly and cyclotron frequencies of trapped particles and antiparticles. Constraints are obtained from existing data on coefficients controlling Lorentz- and CPT-violating operators of arbitrary dimension, and sensitivities in future experiments are discussed.