Drell-Yan at LHC: Proton+Proton Feynman Diagram

[Dan2009]

Hey everyone,

Okay so usually drell-yan is shown as interaction of p + p^bar: quark + antiquark -> virtual photon -> lepton(+) + lepton(-). I have seen diagrams of this for the LHC, which is a PROTON+PROTON collider yet drell-yan is still shown as an antiquark coming from one of the protons which cannot be so. Is there an included process which is not being showing on the spectator diagram?

i.e. What is the Feynman diagram (or spectator model diagram) for Drell-Yan from a Proton+Proton Collision?

Regards,

Dan

 

[Vanadium 50]

There are sea antiquarks. That's where the Drell-Yan comes from.

 

[bomanfishwow]

You also have the case where you have a quark-gluon initial state, where the gluon splits into a quark anti-quark pair. The anti-quark then interacts with a quark from the other proton to give the Drell-Yan part, along with an associated jet in the final state from the 'left-over' quark. Note that here, as well, quark and anti-quark can be swapped (so the initial state is a gluon and anti-quark).

Such processes are normally termed (to experimentalists, at least) QCD corrections to the DY process.