Speaker
Description
Cosmic-ray muons provide a unique probe of both particle interactions and potential signals of new physics. We present a novel cosmic-ray scattering experiment using a resistive plate chamber (RPC) muon tomography system, where the scattering angle between incident and outgoing tracks is exploited as a key observable. This approach enables simultaneous studies of secondary cosmic-ray composition and searches for dark matter interactions. During a 63-day data-taking campaign, $1.18\times10^6$ cosmic-ray scattering events were recorded and analyzed. By performing combined template fits to the measured angular distributions, the abundances of different cosmic-ray components are extracted, with the electron fraction determined at the $\sim2\%$ level. The same dataset is further used to search for elastic muon–dark matter scattering in muonphilic dark matter scenarios. No significant excess above the expected background is observed, and constraints on the scattering cross section are derived. For a $1\,\mathrm{GeV}$ slow dark matter particle, the $95\%$ confidence level upper limit reaches $1.61\times10^{-17}\,\mathrm{cm}^2$. These results demonstrate the potential of cosmic-ray scattering measurements as a novel tool for both precision cosmic-ray studies and searches for light muon-coupled dark matter.
