Searching for Long Lived Neutral Particles in the ATLAS Hadronic Calorimeter

Abstract: The ATLAS detector is sensitive to the decay of neutral, weakly interacting, long-lived particles. Such decays can leave unique, detectable, signatures. This poster concentrates on preliminary results from a search for decays in the hadronic calorimeter in Run II: the search strategy looks for hadronic-only-calorimeter jets that have little or no tracks pointing at them. Many models can contain final states like this: Stealth SUSY, Baryogenesis, and a simple hidden sector scalar that decays to heavy fermion jets. Performance of the ATLAS Calorimeter Ratio trigger along with tools and preliminary results are shown.