In 2012, the last missing piece of the Standard Model (SM) – the Higgs boson – was finally experimentally detected at the LHC. However, this much celebrated discovery also marked the beginning of what is sometimes called the “nightmare scenario at the LHC”. We are certain that the SM is incomplete as, for example, neutrino oscillations and dark matter indicate, yet high-energy collision experiments have not lead to anything new after the great Higgs discovery.
In this situation, precise low-energy tests of the SM offer one of the viable possibilities how to proceed further in our exploration of fundamental physical laws. For example, one could focus on a very subtle effect known as parity violation. As we will show, this effect arises from Glashow-Weinberg theory of electroweak interactions and in atoms is quantified via a so-called atomic parity non-conservation (PNC) amplitude. The comparison of the theoretical and experimental values of the PNC amplitude constitutes one of the most stringent tests of the SM. By reviewing current theoretical and experimental data, we will see, however, that the theoretical results lag behind the latter. Thus, clearly, a more accurate theoretical determination is necessary.
The semina will be chaired by Hynek Němec, Department of Dielectrics.