Background studies to searches for long-lived stopped particles decaying out-of-time with LHC collisions

R-hadrons are massive, long-lived particles predicted in several Supersymmetry scenarios. This note describes a first study of backgrounds to a search for gluino R-hadrons which have come to rest within the ATLAS detector volume, particularly the calorimeter, and decay at some later time, dictated by the lifetime of the particle. We isolate events with jets, potentially produced from the 2- or 3- body decays of the gluinos stopped within the calorimeter. Candidate events are triggered in the empty bunch crossings in order to remove collision backgrounds. Simple selection criteria enable the discrimination of signal-like events from backgrounds, the largest of which is from cosmic muons.