How can we detect dark matter with the Large Hadron Collider?

Question

How will scientists know they found dark matter and when colliding two atoms together how does that enable us to see dark matter? Is finding dark matter the main purpose of the collider, or are there other discoveries we are hoping to make with it?

Answer 1

So the collider runs two protons together with kinetic energy much greater than their mass.  So all sorts of stuff can fly out of the collision. It's like ramming VW beetles into each other and having mack trucks fly out.

The dark matter may be a kind of fundamental particle that is heavier than anything we've ever created before.  By making a collision with enough energy, we will make them if they do, in fact, exist.  The collision is surrounded by a suite of detectors which will be able to tell the mass of the particles that shoot out.  So an exceptionally heavy stable particle would be fairly easy to spot if it were charged and ionizing.  If not, it will show up as missing energy.  The collision is surrounded by calorimeters which can soak up most of the energy, so if a lot escapes (as it does when a neutrino runs ouff), they can tell that.  And if superparticles (one possibility for dark matter) exist, there won't be just one, there will be a bunch, since every known particle has a superpartner.

There are many things we might see.  And what we probably will see is something nobody expected.  LHC is what particle physicists call a discovery machine.  It wasn't created to take a precise measurement of some known phenomenon.  It was created to just ram stuff together with a whole lot of energy and see what will come out.