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that is the nature of quantum physics. Even if the initial conditions would be exactly the same, every collision would have a certain number of possible outcomes (not just one, many!), and there are probabilities (chances) that can be calculated by the physics theory we call the Standard Model, which makes predictions on how often each kind of collision happens. The interesting collisions are really really really rare. But even 'normal' proton-proton collisions are all slightly different.

You mean statistical predictions or there are known factors by which the nature of collision differs?

Both (sorry!), there are known factors that the collisions are different, but also actual are actual statistical probabilities of different things that can happen when exactly the same initial condition occurs. And then there are even more random things like angles, the created particles can essentially fly in any direction after a proton-proton collision. Producing all those random options is one of the reasons we use very advanced simulations to predict what we expect. A substantial fraction of the grid computing power is used to produce those simulations.

I guess it is very intriguing to check the results of every experiment. Thanks for sharing this knowledge.