The Search for Electric Dipole Moments of Charged Particles in Storage Rings

The matter-antimatter asymmetry in the universe, unexplained by theStandard Model of elementary particle physics, requires CP-violatingphenomena, as proposed by A. Sakharov. Subatomic elementary particleswith Permanent Electric Dipole Moments (EDMs) violate timereversal and parity asymmetries, implicating CP violation if the CPTtheorem holds. In addition, the axion or axion like particles (ALPs),initially proposed to explain CP violation in quantum chromodynamicsand potentially constituting dark matter, induce an oscillating ElectricDipole Moment (EDM) along the spin direction when coupled withgluons.The Cooler Synchrotron COSY at Forschungszentrum Jülich providespolarized and unpolarized protons and deuterons up to a momentumof 3.7 GeV/c and serves as an ideal platform for the JEDI -Collaboration (Jülich Electric Dipole moment Investigations) to conductthe first direct measurement of the permanent deuteron EDMby observing its influence on spin motion. In addition to this measurementof the static EDM, upper limits of the oscillating deuteronEDM due to Axions or ALPs have been measured. Both effects resultin a build-up of a vertical polarization component which can bemeasured with a polarimeter. This presentation will describe both thepermanent EDM and the oscillating axion-induced EDM experiments.