A study on investigation of FCNC tqZ couplings via vZp production at future electron-proton colliders

In the standard model, top quark flavor changing neutral currents are absent at the tree-level. As a consequence, processes involving these currents can be generated at loop-level and thus are expected to be strongly suppressed. Nevertheless, they can be enhanced in the presence of new physics beyond the standard model and tested at future colliders with high energy. In this thesis, we investigate the top quark anomalous flavor changing neutral current tqZ within the framework of effective field theory to probe the best limits on the tqZ couplings, namely K_utandK_ct, via single top production in the e p→υ_(e ) Z q process at the future LHeC and FCC-he colliders. The signal and SM background events are generated using a Madgraph and Delphes was used to include realistic detector effects. We have found that the cross sections of the signal increase remarkably when we take large values of the couplings and set K_ut=K_ct. In addition, we have studied the kinematic distributions of the final states particles and found that applying certain cuts can enhance the signal. Our study shows that FCC-he gives the best limits BR (t → qZ) for (Z→ ll) = 4×〖10〗^(-4).