FCNC production of same sign Top quark pairs at the LHC

We study the possibility of same sign top quark pair production at the LHC (and the VLHC) as a direct probe of FCNC processes. Besides the SM neutral Z boson, two other neutral bosons are considered, a top-Higgs type scalar and a Z' boson that appear in Topcolor assisted Technicolor models. We find that the FCNC couplings tqV (q=u,c ; V=H,Z,Z') may produce an interesting signal of same sign top quark pairs that could be observed at the LHC (VLHC).