The public repository, called HepSim, was started during the United States’ long-term planning study of the American Physical Society’s Division of Particles and Fields (Snowmass 2013). It provides Monte Carlo event samples for physics and detector-performance studies for the Large Hadron Collider (LHC), High-Luminosity LHC, International Linear Collider (ILC), Circular Electron Positron Collider (CEPC), Future Circular Collider (FCC), and other future colliders.

HepSim repository is anchored on the computational capabilities of the Chicago area, such as Open-science grid Connect (OSG-CI, University of Chicago/Argonne), Blue Gene/Q supercomputer of the Argonne Leadership Computing Facility, and ATLAS support center (ASC, High Energy Physics Division at Argonne).