Searching for Lorentz violation in weak decays
Prof. Dr. Hans W. Wilschut (Van Swinderen Institute, Rijksuniversiteit Groningen, The Netherlands)

Lorentz violation is a necessary condition for violating CPT invariance. Weak interactions violate the discrete symmetries C, P, CP and T, suggesting the relevance of searches for Lorentz violations (LV) in weak interactions, however relatively few searches have been made.

We performed a β-decay experiment that tests the dependence of the lifetime on the absolute orientation of the nuclear spin in space. Such dependence would indicate violation of rotational invariance, and therefore imply LV. In addition we have examined experiments from literature that also allow bounds on LV. The various bounds can be discussed in a theoretical framework that was developed in the theory group of the Van Swinderen Institute and also relates to Kostelecky’s approach.

We discuss some ideas how to push the current limits beyond the current limits of about 10^-8 and to obtain limits in the parameter space not yet explored.