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

Understand

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.