Charged long-lived particles in the GMSB scenario at the Future Circular Collider (FCC-ee)

Long-lived particles have emerged as a compelling signature of physics beyond the standard model, offering unique discovery opportunities at current and future colliders. We present an analysis of charged long-lived particles leading to signatures with kinked tracks and displaced vertices. Our study is motivated by the gauge mediated supersymmetry breaking model (GMSB) within the minimal supersymmetric standard model scenario, in which the lightest supersymmetric particle is a gravitino and the next-to-lightest supersymmetric particle is the stau, the superpartner of the tau lepton. The stau is predicted to be long-lived due to the small coupling between it and the gravitino. This work presents a phenomenological study of such long-lived staus with lifetimes between 20~cm and 20~m and explores their discovery prospects at the Future Circular Collider (FCC-ee), a proposed $e^{+}e^{-}$ collider. The results highlight the sensitivity to the GMSB model.