What the Atlas subsystem does is that it detects subatomic particles called muons. These particles have little interaction with each other or with other matter and are formed as a byproduct of the collisions between protons, the nuclei of hydrogen atoms. The collider will provide far too much data for scientists to log all of it, so the first appearance of muons can be a signal that scientists need to record information on collisions taking place at that time.
According to Professor Henry Lubatti from the university of Washington, "They are like little messengers that tell us a potentially interesting event may have occurred, a signal that we should look more closely at that event." Potentially that could lead to direct evidence of the elusive Higgs boson.
"That's just one example of the detector's value. There are many other interactions that produce high-energy muons, so it is very important to be able to observe these," said Lubatti. The Large Hadron Collider could also lead to better understanding of the fourth fundamental force - gravity - in terms of particle interactions, and help solve the puzzle of why gravity, while perhaps most recognizable to a lay observer, is the weakest of the fundamental forces.