There are many equations. For instance, if you really want to know what is going on at the hardest level (i.e. where one expects new particles to be produced), the model Lagrangian is the equation that matters (it could be the Standard Model or any model you may dream of). Strong interactions is very important, as we are colliding very energetic protons. Them if you are interested on the detector side, how visible particles interact with matter matters. And so on. There are many very relevant equations all over the place, and all are necessary at the end of the story.