MUSE

 

Main Project: 

MUSE will perform muon-proton scattering mainly motivated by the proton radius puzzle. The proton radius puzzle started in 2010 when the CREMA collaboration measured the proton charge radius with muonic atoms and found a 7σ discrepancy with the CODATA value. Since then multiple experiments aimed at measuring the proton charge radius have been performed, in the nuclear and atomic physics communities, and the results are inconclusive. MUSE aims to measure the proton radius using simultaneous electron-proton and muon-proton scattering at the PiM1 secondary beamline at the Paul Scherrer Institute. This simultaneous measurement is the first of its kind, and aims to be the most precise muon-proton scattering measurement in the kinematic region sensitive to the proton charge radius. In addition, MUSE will provide data for both positive and negative leptons, testing radiative corrections, especially two-photon exchange. It will also provide important data on pion-proton scattering.

 

Our Publications:

 W. Lin, et al., The MUSE Beamline Calorimeter, in preparation J. C. Bernauer, E. W. Cline, et al., Blinding for precision scattering experiments: The MUSE approach as a case study, (2023):

https://arxiv.org/abs/2310.11469

L. Li, S. Strauch, et al., Instrumental uncertainties in radiative corrections for the MUSE experiment, (2024), EPJ A:

https://doi.org/10.1140/epja/s10050-023-01215-0

E. Cline, W. Lin, P. Roy, P. E. Reimer, K. E. Mesick, et al., Characterization of muon and electron beams in the Paul Scherrer Institute PiM1 channel for the MUSE experiment, (2022), Phys. Rev. C:

https://doi.org/10.1103/PhysRevC.105.055201

L. Li, S. Strauch, et al., Instrumental uncertainties in radiative corrections for the MUSE experiment, (2024), EPJ A:

https://doi.org/10.1140/epja/s10050-023-01215-0

E. Cline, J. C. Bernauer, E. J. Downie, R. Gilman, MUSE: The MUon Scattering Experiment, (2021):

https://doi.org/10.21468/SciPostPhysProc.5.023

R. Gilman, et al., Technical Design Report for the Paul Scherrer Institute Experiment R-12-01.1: Studying the Proton "Radius" Puzzle with μp Elastic Scattering, (2017):

https://arxiv.org/abs/1709.09753

A. Afanasev, et al., Radiative Corrections: From Medium to High Energy Experiments, (2023), in press:

https://arxiv.org/abs/2306.14578