The approach for the observation of the first J/ψ → μ+μ−
production using the ATLAS detector at the Large Hadron Collider will be presented. Given the large quarkonia cross sections, large sample of muons can be obtained with
few pb−1. These clear muon samples can be used to study the Muon Spectrometer in all his aspects, like detector alignment, trigger calibration and trigger efficiency.
Events of interest can be triggered by requiring one or two isolated muons; offline selection can then be applied, consisting maily of muon pseudorapidity cuts and lepton transverse-momentum threshold
