Efficiency characterization of the ATLAS diphoton and combined photon plus multijet triggers using physlite derivations, with applications to stealth SUSY searches

The ATLAS experiment in the LHC Run-3 is recording up to 3 kHz of fully-built physics collision events out of an LHC bunch crossing rate of up to 40 MHz. A two-level trigger system selects events of interest to cover a wide variety of physics while rejecting a high rate of background events. The selection of events targets both generic physics signatures, such as photons, jets, missing energy, as well as more specific signatures targeting specific physics events, from Standard Model processes to searches for new phenomena. Triggering these particles is essential for signal selection, and also for calibration, efficiency and fake rate measurements. As part of the ATLAS physics programme, the SUSY Strong Stealth analysis targets an uncovered phase space with a final state featuring 2 photons, at least 6 jets and no missing energy. The considered triggers, although are generic in the sense that multiple analysis will use them, are going to be used by this search for event selection and data-driven background estimation techniques.