Search for New Physics with Long-Lived Neutral Particles in ATLAS: The Hidden Valley Scenario

With the start of the Large Hadron Collider a new energy frontier will be accessible to experimental particle physics, and many new models and extensions to the Standard Model will be tested. A unique class of these new models are those in which long-lived particles can decay mid-detector, leaving atypical signatures that are often missed by standard LHC-detector triggers. Such models include the Hidden Valley models and some supersymmetric models. Prospects for triggering-on and detecting long-lived neutral particles in the ATLAS detector are presented.