ERC Consolidator grant for Paolo Crivelli

Dr Paolo Crivelli (ETH Zurich, Department of Physics, Institute for Particle Physics and Astrophysics) has recently been awarded an ERC Consolidator grant for his project "Mu-MASS" aiming at a new precision measurement of the Muonium 1S-2S transition energy, ultimately with an improvement by three orders of magnitude. Muonium is the hydrogen-like atom formed by a positive muon and an electron. Its energy levels are, in contrast to the case of ordinary hydrogen, completely dominated by Quantum-Electro-Dynamics (QED) and precision QED calculations are currently ahead of experiment. It will be the first time that CW two-photon spectroscopy is applied to muonium. Results will improve our knowledge of the muon mass, test bound state QED and search for physics beyond the Standard Model of Particle Physics. Moreover, it will help to resolve the present 'proton radius puzzle' by providing a determination of the Rydberg constant free of finite size effects. While Dr. Crivelli is located at ETH H&oml;nggerberg, he and his team will spend a large amount of time at PSI and collaborate closely, both, with the NUM laboratories for Muon Spin Spectroscopy and for Particle Physics.