Beam and Spin Dynamics for Storage Ring Based EDM Search

Abstract

Permanent EDMs (electric dipole moment) of fundamental particles violate both time invariance T and parity P. Assuming the CPT theorem this implies CP violation. The Standard Model (SM) predicts non-vanishing EDMs, their magnitudes, however, are expected to be unobservably small with current techniques. Hence, the discovery of a non-zero EDM would be a signal for “new physics”. As a first step towards EDM searches of charged particles in storage rings, R&D work at the Cooler Synchrotron COSY is pursued. On a longer time scale, the design and construction of a dedicated storage ring will be carried out. Spin-tracking simulations are absolutely crucial to explore the feasibility of the planned storage ring EDM experiments and to investigate systematic limitations. For a detailed study during the storage and buildup of the EDM signal, one needs to track a large sample of particles for billions of turns. Benchmarking experiments are performed at the Cooler Synchrotron COSY to check and to further improve the simulation tools and prototype accelerator components are tested. Finally, the layout of a dedicated storage ring has to be optimized by a full simulation of spin motion.