Development of a cold atomic muonium beam for next generation atomic physics and gravity experiments

A high-intensity, low-emittance atomic muonium (M =\mu^+ + e^- =μ++e− ) beam is being developed, which would enable improving the precision of M spectroscopy measurements, and may allow a direct observation gravitational interaction. Measuring free fall atoms be first test weak equivalence principle using elementary antimatter ( \mu^+ display="inline">μ+ purely leptonic system. Such an experiment relies on high intensity, continuous muon beams available at Paul Scherrer Institute (PSI, Switzerland), proposed novel source. In this paper, theoretical motivation principles are described.