Search For Long Lived Particles in ATLAS and CMS

The ATLAS and CMS detectors can be used to search for heavy long-lived particles which might signal physics beyond the Standard Model. Such new states can be distinguished from Standard Model particles by exploiting their unique signatures, ranging from multi-leptons and/or jets production anywhere within the detector volume, for long-lived neutral particles, to the presence of particles with low velocity, associated with a high momentum of order a few hundred GeV/c, for meta-stable charged massive particles. Here we describe the strategies proposed by ATLAS and CMS to search for these signals, focusing on the challenges to the trigger and detector operations posed by the peculiar topologies that are involved. Various models predicting different types of long-lived states are used as benchmark for the proposed search strategies, and results based on the full simulation of the ATLAS and CMS detectors are presented, including the expected performance and resolutions which could be obtained using the first data at the LHC.