Speaker
Description
Searches for low-mass dijet resonances at the LHC use hard initial-state radiation, either an isolated photon or a jet, to reach masses below the unprescaled trigger threshold. As the luminosity rises, more collisions are produced, so the unprescaled trigger has to raise its threshold to stay within the limited bandwidth and storage. Even with initial-state radiation, the low-mass region is still hard to reach unless lower-threshold triggers are used and only a fraction of events are kept. In this phenomenological study, simulated events of a hypothetical new particle decaying to dijets and produced in association with a photon or a jet are used to study the mass region below 600 GeV. Sensitivities from lower transverse momentum(pT) selections are compared with an unprescaled high pT baseline in each channel in order to extract the critical prescale values. These values show how strongly a lower-threshold trigger can be prescaled while remaining competitive with the corresponding baseline. They offer practical guidance for future trigger choices when exploring the low-mass dijet region. Unlike techniques such as trigger-level analysis or seeking new physics in pile-up events, the approach presented in this work uses a standard analysis chain, which can be implemented seamlessly. It complements the quest to probe low-mass resonances using the potentially under-explored prescaled triggers.
