Configuration, Performance, and Commissioning of the ATLAS $b$-jet Triggers for the 2022 and 2023 LHC data-taking periods

Abstract

In 2022 and 2023, the Large Hadron Collider produced approximately two billion hadronic interactions each second from bunches of protons that collide at a rate of 40 MHz. The ATLAS trigger system is used to reduce this rate to a few kHz for recording. Selections based on hadronic jets, their energy, and event topology reduce the rate to $\mathcal O(10)$ kHz while maintaining high efficiencies for important signatures resulting in $b$-quarks, but to reach the desired recording rate of hundreds of Hz, additional real-time selections based on the identification of jets containing $b$-hadrons ($b$-jets) are employed to achieve low thresholds on the jet transverse momentum at the High-Level Trigger. The configuration, commissioning, and performance of the real-time ATLAS $b$-jet identification algorithms for the early LHC Run 3 collision data are presented. These recent developments provide substantial gains in signal efficiency for critical signatures; for the Standard Model production of Higgs boson pairs, a 50% improvement in selection efficiency is observed in final states with four $b$-quarks or two $b$-quarks and two hadronically decaying $\tau$-leptons.