What happens when two electrons collide at high velocity?

[Carboxyl]

what happens when you smash two electrons together at a high velocity?

 

[blechman]

you mean like this?

http://public.web.cern.ch/public/en/research/lep-en.html

 

[kaksmet]

what happens when you smash two electrons together at a high velocity?

That my friend, is a question with many different answers, coming with very different probabilities.

Or, you can summarize it with:
Something will come out from the collision.