Experiments are conducted at the four gigantic detectors which can be found along the accelerator including A Toroidal LHC ApparatuS (ATLAS). Inside of the circular tunnel of the LHC, beams of protons in opposite directions are accelerated by a magnetic track to relativistic speeds, which will then collide at any of the four large detectors. In this explosion, the proton beams are collided and new particles are created from the resulting energy. By looking at all the particles, we are able to infer from the presence of other particles from the missing energy. Muons and neutrinos are expected to make it outside of the detector. The electrons and other charged particles interact in the inner detector and calorimeter, neutral particles left are muon detector without interaction so particle from beam collisions that are measured in the muons spectrometer are mostly muons.
More information about the ATLAS experiment can be found here.