Analysis of Long-Lived Slepton NLSP in GMSB model at Linear Collider
  We performed an analysis on the detection of a long-lived slepton at a linear collider with $\sqrt{s}=500$ GeV. In GMSB models a long-lived NLSP is predicted for large value of the supersymmetry breaking scale $\sqrt{F}$. Furthermore in a large portion of the parameter space this particle is a stau. Such heavy charged particles will leave a track in the tracking volume and hit the muonic detector. In order to disentangle this signal from the muon background, we explore kinematics and particle identification tools: time of flight device, dE/dX and Cerenkov devices. We show that a linear collider will be able to detect long-lived staus with masses up to the kinematical limit of the machine. We also present our estimation of the sensitivity to the stau lifetime. 
Pedro G. Mercadante, J. Kenichi Mizukoshi, Hitoshi Yamamoto