[whatshisface]

One thing that might help is that the collision vertex is slightly different each time. If you already had all of the tracks reconstructed, you'd find that you could point them together into n different centers of mass from which they originated.

[Analog24]

Vertex finding is the first step in most track reconstruction algorithms. But it's still very difficult. The number of trajectories that can be formed from discrete points blows up combinatorically. When you have hundreds of thousands of points you usually don't end up with a few easy to find vertices.

[dukwon]

This is already what happens. The problem is that forming tracks and vertices becomes much harder as the number increases.