One of the predicted decays of the Higgs is into two muon-antimuon pairs. In this ATLAS event, this is seen as four long tracks (displayed in purple) which intersect highlighted green rectangular muon chambers. The mass of the possible parent particle is calculated to be 124.6 GeV, well within the range for the Higgs based on latest data. Is it a Higgs boson? We just don't know.
Credit: ATLAS Experiment© 2011 CERN