Helium-Xenon spin clocks: A new limit on the 129Xe
Ulrich Schmidt (Universität Heidelberg)

Physikalisches Institut, Universität Heidelberg The Baryon asymmetry is one of the unsolved big questions of Cosmology. Most explanations for the Baryon asymmetry involve modifications of the Standard Model which generate additional CP violating interactions. This is one reason to search for CP violating interactions beyond the Standard Model. These CP violating interactions will also generate Electric Dipole Moments (EDM) of elementary particles, which are experimentally detectable.
In my talk, I will motivate in a nut shell why the discovery potential of a baryonic EDM in a complex, composite system like the 129Xe nucleus may be higher than the discovery potential of the direct search for the EDM of the baryons of interest: proton and neutron.
Second I will introduce our experimental method: The He-Xe-spin clock. He-Xe-spin clocks are the most accurate clocks today and we reached already an accuracy level well beyond nHz. Our setup is located at the Forschungszentrum Jülich and I will present the first preliminary result of our ongoing 129Xe EDM search performed by the MIXe⃗d collaboration (Measuremnet and Investigation of the 129Xenon electric dipole moment).
Beside the search for a 129Xe EDM we used He-Xe-spin clocks to search for a Lorentz invariance violating preferred frame interaction in a Huges-Drever like Experiment and the direct search for Axion like interaction. Finally I will briefly discuss our plans to search for Axion like Dark Matter.