CMS completes high-pileup collision test, validating particle reconstruction algorithms for High-Luminosity LHC operation
In 2025, the Large Hadron Collider (LHC) conducted a dedicated test over several days to simulate high-intensity collision conditions closer to those expected during future operation of the High-Luminosity Large Hadron Collider (HL-LHC). The Compact Muon Solenoid (CMS) experiment team used this opportunity to test whether existing particle tracking, identification, and reconstruction software, along with a new class of machine learning methods, can adapt to the more complex collision conditions of the HL-LHC era. During LHC operation, each crossing of proton beams produces multiple proton–proton collisions simultaneously, a phenomenon known as pileup. The current Run 3 features approximately 65 simultaneous interactions, while the HL-LHC is expected to reach 140 to 200. To...
2026-08-10
