Simple Atoms for Complex Questions in Fundamental Physics

The simplest atomic systems, positronium and muonium, are exceptionally sensitive probes of bound-state quantum electrodynamics, tests of fundamental symmetries, and searches for physics beyond the Standard Model. In this seminar I will present our recent results from precision spectroscopy of positronium and muonium, and discuss how new experimental developments, including improved sources and new detection schemes, open a path to substantially higher precision. I will highlight how these advances connect to determinations of fundamental constants, such as the muon mass, and to complementary tests of new physics with matter–antimatter systems.