Why LHC use proton-proton collide instead of proton-antiproton(like,Tevatron) collide?
you only need one magnet ring, instead of two since the antiproton has opposite charge.
for some processes, the reaction rate is higher for p-bar + p than p+p, but only at "low" energies such as 1-3TeV (which is energy for the Tevatron), but for higher energies, such as 10 (LHC range), this advantage dissapears.
So the advantages is that you only need one set up of magnet rings, and that at lower E, reaction rate is higher for some processes.
Disadvantages is that producing and facilate antiprotons is very diffcult, and that the higher reaction rate is reduced when increasing the energy.
If there are any vector particles to be discovered in the mass range of 2 to 12 TeV, the proton anti-proton collider can produce a clean signal of a particle decaying near at rest, while the proton-proton collider produces the same signal along with 100 tons of other garbage that you have to sort through very very carefully.
However, for the LHC, there is no reason whatsoever to make antiprotons - you don't gain anything (gluon pdfs are the same in both p and pbar), and you loose out from the complications (both in luminosity and cash!) of making antiprotons.