Speaker
Description
We propose a new search strategy for long-lived doubly charged scalars at future lepton colliders. These particles arise in models that explain tiny neutrino masses via the Type-II seesaw mechanism. For certain masses and parameters, they can travel a measurable distance before decaying into same-sign muon pairs, producing clear displaced-vertex signatures. We study their production at the International Linear Collider (ILC) and a future muon collider, focusing on final states with four leptons and missing energy. We also show that measuring the combined mass of same-sign lepton pairs provides an additional powerful way to identify these particles. Altogether, our approach improves the chances of discovering doubly charged scalars at future collider experiments.