Question: hey jimmy! after some reading about the Large Hadron Collider and it's very impressive instruments to detect and investigate the collision results, ,what is the diffrence between leptons and of hadrons?, What would happen if leptons would collide electrons? plus Isn't it intrinsic that all particles consist of smaller particles? With current technology, could we detect them? p.s did you ever get to meet brian cox and talk about your field of work.

James Holloway answered on 18 Mar 2013:

Hi bilallatif,

Yes the machine at CERN is truely impressive bit of kit. The detector is as big as a house!

So leptons are a family of elementary particles (not made of smaller ones) that has certain propeties. Electrons are leptons, muons is like the heavier older brother of the electron, and tauons is the heavier eldest brother. The key thing about this family is they feel the electomagnatic force, but not the ‘strong’ force.

The Hadron family feel both these forces. Also, they are not elementary particles – they are made up of quarks. Both familys are fundamentally distinct.

If you collided them strongly enough then the leptons could smash apart the hadrons, creating a shower of new particles. This is similar to what happens when you collide hadrons and hadrons. And yes the detectors at the LHC are designed to detect all the new stuff that comes out of collisions like this.

not all particles are made of smaller ones, otherwise there would be ever smaller and smaller particles with no end in sight!

Never met Brian Cox sadly, I have met the late Sir Patrick Moor though, who is like the grandfather of astrophysics!