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

TL;DR

This paper details the configuration, commissioning, and performance of ATLAS b-jet triggers during the 2022-2023 LHC runs, highlighting significant improvements in signal efficiency for key physics signatures.

Contribution

It introduces new real-time b-jet identification algorithms that enhance trigger efficiency and are tailored for the early Run 3 data-taking period.

Findings

50% improvement in Higgs pair production signal efficiency

Effective real-time b-jet identification algorithms implemented

Enhanced trigger performance for important physics signatures

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.