Displaced Tracking at a Muon Collider with Long-lived Staus

A future 10 TeV muon collider offers many opportunities to search for new fundamental particles. This study investigates the impact of beam-induced-background (BIB) on long-lived particle (LLP) searches. BIB leads to a diffuse shower of low energy, non-pointing, and out-of-time particles. Existing mitigation techniques, specifically hit timing and track pointing requirements, would result in negligible sensitivity to LLPs. We consider a Supersymmetry benchmark model with long-lived staus, in which each stau decays to a tau and a Dark Matter particle. We use the stau and its decay products to evaluate the reconstruction efficiency for slowly moving tracks and displaced tracks, respectively. We evaluate efficiency for varying levels of BIB rejection and investigate the corresponding computational challenges. This work also gives insight into possible analysis strategies and overall sensitivity to long-lived staus.