Comparison of GEM Performance with 1D and 2D Clusters (MUSE)

The difference between the proton radius measured by hydrogen spectroscopy and electron scattering, and the proton radius measured with muon spectroscopy, known as the proton radius puzzle, has been unresolved for over a decade. The MUSE experiment at Paul-Scherrer Institute (PSI) was designed to provide the first high precision muon scattering radius measurement to resolve the puzzle. The MUSE experiment simultaneously measures electron and muon scattering, and measures alternately with both beam polarities as a check of higher-order corrections that might affect the radius extraction. The experiment is composed of many hardware components which includes a Gas Electron Multiplier (GEM) telescope to determine particle trajectories. This presentation will give an overview of the formation of 1D and 2D clusters, charge sharing, and the tracking performance of the GEM detectors by comparing the 1D clusters and the 2D clusters.