PSILOGO

Laboratory for Particle Physics (LTP)


LTP Colloquium

The Mu-MASS Experiment

Thursday, November 2, 2023, 16:00
WBGB/019

Paolo Crivelli, ETHZ

Abstract:
In this seminar, I will present the overview of the Mu-MASS experiment at PSI focusing on Muonium (M) spectroscopic studies. Mu-MASS aims at improving the determination of the 1S-2S transition frequency of M. Such a measurement will provide the most accurate value of the muon mass. Combined with an improved determination of the ground state hyperfine structure of M ongoing at JPARC, it will yield a value of the Rydberg constant free of finite size effects and result in one of the most stringent test of bound state QED to the ppb level.

I will report our recent results on a precise determination of the M Lamb shift at the low-energy-muon (LEM) beamline. Since our measured value matches the theoretical calculations within one standard deviation, we could set stringent limits on Lorentz/CPT violation in the muonic sector, as well as on new physics coupled to muons and electrons which could provide an explanation of the muon g-2 anomaly.

I will conclude highlighting the prospects for muonium spectroscopy at PSI with MuCool and the HIMB upgrade.