The Low-Energy Frontier of the Standard Model

Low-energy precision measurements are well-known probes of the Standard Model and beyond. We discuss some highlights in that research field, carried out by physicists from Johannes Gutenberg University Mainz at the local MAMI (Mainz Microtron) accelerator and at the BES III experiment in Beijing (*). This includes measurements of meson form factors relevant for the hadronic contributions to the anomalous magnetic moment of the muon, (g-2)_mu, and searches for particles of a hypothetical dark sector. Moreover, we also present future opportunities for precision physics at the high-intensity electron accelerator MESA (Mainz Energy-recovering Superconducting Accelerator), which currently is under construction in Mainz. At MESA, among other topics, a precision measurement of the electroweak mixing angle, sin² theta_W is foreseen.

(*) funded by CRC-1044 "The low-energy frontier of the Standard Model" and PRISMA+
Cluster of Excellence