Speaker
Description
Many beyond-the-standard-model theories allow for new particles with long lifetimes. These long-lived particles will decay away from the primary interaction point, and many searches for these displaced decays have been performed by both ATLAS and CMS. However, spatial displacement is not the only signature of long-lived particles, since sufficiently massive ones also incur a time delay. Timing information from the ATLAS calorimeter systems can be used to measure these delays, supplementing sensitivity for long-lived particle scenarios in a detector region where spatial granularity drops and displaced searches are less efficient. This talk will introduce a search targeting R-parity violating neutralinos and a heavy Higgs signal decaying to delayed jets, and discuss the unconventional background sources that are present in this experimental signature. One background source will be highlighted in particular: collisions between "satellite" bunches, which are bunches of protons in RF buckets outside of the nominal bucket.