Long-Lived Particle Reconstruction at CLIC

Several Beyond Standard Model theories predict the existence of particles whose lifetime is at the millimeter scale. If generated in a high energy collider, these particles could live long enough to travel in the detector tracking system for a few centimeters. Before decaying, they could leave several detectable hits, that can be clustered by the algorithms into a stub track. Hence, the search of long-lived particles (LLPs) is very well-motivated in high energy colliders with high-resolution tracking detectors and robust reconstruction algorithms. The proposed future e+ e− linear collider CLIC provides the perfect environment for the search of these particles, thanks to the lack of QCD-background and its detector low material budget. The presented work tested the CLIC third stage (√s = 3 TeV) reconstruction performances, analyzing simulated stub tracks originating from LLP pair production. In particular, the particles involved were charginos with lifetime cτ ≈600 mm and mass m≈1.5 TeV. LLP tracks were found to be reconstructable in more than 90% of the cases in the detector central region.