Testing Lorentz and CPT Symmetries in Penning Traps
Spacetime symmetries play a crucial role in understanding our nature. Especially, invariances under Lorentz and CPT transformations are foundations of General Relativity (GR) and the Standard Model of particle physics (SM), the two current best theories describing nature. However, tiny violations of these symmetries could appear in a more fundamental theory unifying gravity with quantum physics. Motivated by this, numerous high-precision experiments spanning various subfields of physics have been performed to search for possible Lorentz- and CPT-violating signals. In this talk, I will focus on the prospects of testing Lorentz and CPT symmetries using confined particles and antiparticles in Penning-trap experiments. The theory of Lorentz- and CPT-violating quantum electrodynamics will be outlined. Leading-order effects to charge-to-mass ratio and magnetic moment measurements and their comparisons between particles and antiparticles will be derived. In particular, experimental signals involving sidereal and annual variations due to Lorentz and CPT violation will be discussed. Using existing results from Penning-trap experiments, new constraints on coefficients for Lorentz violation will be presented.