Question: What do you your look for in sub-atomic particles?

Lily Asquith answered on 21 Jun 2010:

With protons, I smash them together to release enough energy to drag new particles out of the vacuum. Then I look for evidence of the new particles with the ATLAS detector.

If a new particle is charged it leaves tracks a bit like an aeroplane leaves a trail in the sky so you can see where it has been. You can work out what kind of particle it was by examining the way the tracks curve and also by detecting how much energy it dumps in the detector.