It's a long way down the rabbit hole. There's a series of steps for measuring in a particle accelerator and each itself is a big area of knowledge: - Detectors - Hardware triggers - Software triggers - Data storage - Statistical analysis

I guess Wikipedia can give you an idea: http://en.wikipedia.org/wiki/ATLAS_experiment A common statistical method used in particle physics is the Monte Carlo method: http://en.wikipedia.org/wiki/Monte_Carlo_method