Precision Tests of Fundamental Physics with Highly Charged Ions and Antiprotons in Penning Traps

Precise experiments on cooled particles in ion traps have opened opportunities for fundamental tests of physical theories. The determination of the magnetic moment of the electron, bound in highly charged ions, is a sensitive test of the theory of bound-state quantum electrodynamics in the strong-field regime. Such precision experiments make it possible to determine fundamental constants, like the electron mass, the fine-structure constant, and the proton magnetic moment. The observation of spin flips with a single trapped proton has paved the way for a comparison of the proton and antiproton magnetic moments as a test of matter-antimatter symmetry (CPT invariance) with high sensitivity. The cooling and non-destructive detection methods employed in precision trap experiments enable the storage and studies of trapped particles at cryogenic temperatures over a time period of more than one year with utmost accuracy. Future precision experiments on heavy highly charged ions will be possible at the HITRAP facility at the ESR storage ring at GSI.