Cosmic-ray studies with the MATHUSLA experiment

The MATHUSLA experiment is designed to investigate the possibleexistence of particle dark matter in the form of Long-Lived Particles(LLPs) produced in proton-proton collisions at the CERN High-LuminosityLarge Hadron Collider (HL-LHC). Since the MATHUSLA detector will cover awide area of the order of $10^{4}$ m$^2$, with 9 layers ofscintillating-detector planes, it can be used for cosmic-ray studies aswell by extending its original set-up with the insertion of afull-coverage layer of Resistive Plate Chambers (RPCs). This will resultin a crucial improvement in detecting extensive air showers produced byprimary cosmic rays and reconstructing the arrival directions, and willallow detailed studies of parallel-muon bundles. The detection ofhadronic showers, and the resulting study of the energy spectrum andcomposition of cosmic rays, will allow a test of hadronic-interactionmodels and will extended the investigation of the origin and propagation ofprimary cosmic rays. In this work, an outline of the MATHUSLA experiment and itspotentialities in cosmic-ray studies are presented.