A number of extensions of the Standard Model results in particles that are neutral, weakly coupled and have macroscopic decay lengths comparable with LHC detector dimensions. In the Hidden Valley (HV) models long-lived neutral particles that decay to heavy flavors or pairs of boosted leptons (lepton-jets) can be produced in SUSY processes, Z' decays and Higgs boson decays. Results are
presented of a study of the ATLAS Detector performance for the Higgs decays h0 → π0vπ0v → b¯bb¯ b, and h0 → π0vπ0v → UUUU → 4(l+l−), where both π0v and U are neutral and can have a displaced decay. Triggers for processes with such nonstandard signatures have been developed and are now included in the trigger menu for data taking
