Field Excitations and their Collisions

[Ryan Reed]

How do collisions occur between different particles when the field excitements that make them are not the same? Also how do you collide when the field are the same? Wouldn't the values of the field just increase until the particles pass through each other? (Like a constructive wave). What I mean by all this is that all fundamental particles are excitations within a field, like the higgs boson, which is an excitation in the higgs field. How would a gluon(strong) interact with a photon(electromagnetic) if the fields they disturb are different?

 

[Orodruin]

This is generally described by interaction terms in the Lagrangian. You do not need to go to quantum mechanics to see how different fields may influence each other, already in classical electromagnetism the electric and magnetic fields interact, which in the extension leads to how electromagnetic waves propagate.

When it comes to particle collisions, the Lagrangian essentially tells you how the fields interact with each other. From this you may compute the cross sections involved when particles collide with each other (ie, what excitations will be in the out state based on what is in the in state). A field may also have non linear interactions with itself, this would manifest itself as particles interacting with particles of the same type.

How would a gluon(strong) interact with a photon(electromagnetic) if the fields they disturb are different?

This is a very badly chosen example. Gluons do not carry electric charge and photons do not carry colour charge, ie, photons and gluons do not interact with each other.