Performance of the ATLAS muon trigger in pp collisions at $\sqrt{s}=8$ TeV

TL;DR

This paper evaluates the performance of the ATLAS muon trigger system during 2012 pp collisions at 8 TeV, demonstrating its efficiency, stability, and agreement with simulations across various muon sources.

Contribution

It provides a detailed measurement of the muon trigger efficiency over a wide pT range and compares it with simulations, enhancing understanding of trigger performance in high-energy collisions.

Findings

Muon trigger efficiency exceeds 99% for pT > 25 GeV.

Performance remains stable and uniform across the dataset.

Good agreement between measured data and simulation predictions.

Abstract

The performance of the ATLAS muon trigger system is evaluated with proton-proton collision data collected in 2012 at the Large Hadron Collider at a centre-of-mass energy of 8 TeV. It is primarily evaluated using events containing a pair of muons from the decay of $Z$ bosons. The efficiency of the single-muon trigger is measured for muons with transverse momentum 25 < $p_T$ < 100 GeV, with a statistical uncertainty of less than 0.01% and a systematic uncertainty of 0.6%. The $p_T$ range for efficiency determination is extended by using muons from decays of $J/\psi$ mesons, $W$ bosons, and top quarks. The muon trigger shows highly uniform and stable performance. The performance is compared to the prediction of a detailed simulation.