Atomic physics tests of discrete symmetries
Dr. Lorenz Willmann (KVI Groningen)

The discrete symmetries Parity (P), Time-reversal (T) and Charge conjugation (C) play a central role in the Standard Model (SM) of the electro-weak interactions. In 1957 it was discovered that P is maximally violated in the weak interaction. A few years later, a small violation of the combined symmetry CP was discovered. CP violation is thought to be a source for the matter-antimatter asymmetry in the universe. Is there more symmetry violation in nature? At KVI, we are probing discrete symmetries in several experiments with heavy rare isotopes,. These are produced at the TRImP facility. Symmetry violating effects in atoms increase stronger than the third power of the atomic number Z.,favoring the use of heavy elements. Of particular interest are searches for permanent electric dipole moments (EDMs) which would violate P and T at the same time. Radium isotopes are expected to be uniquely sensitive to EDMs due to their nuclear and atomic structure. An experimental search for an EDM is possible due to the combination of nuclear physics for the production of the isotopes and the high precision atomic physics methods. Within the experimental program we extended laser cooling techniques to the alkaline earth element barium. Furthermore, atomic parity violation (APV) can be measured in radium ions and atoms. This opens the possibility to determine the weak mixing angle or Weinberg angle in an atomic physics experiment with unprecedented accuracy. We are preparing an experiment which exploits the start-of-the-art ion trapping and laser spectroscopy methods.