Top quark FCNC couplings at future circular hadron electron colliders

A study of single top quark production via flavor changing neutral current interactions at tq gamma vertices is performed at the future circular hadron electron collider. The signal cross sections for the processes e(-) p -> e(-) W-+/- q + X and e(-) p -> e(-) W-+/- bq + X in the collision of an electron beam with energy E-e = 60 GeV and a proton beam with energy E-p = 50 TeV are calculated. In the analysis, the invariant mass distributions of three jets reconstructing top quark mass, requiring one b-tagged jet and two other jets reconstructing the W mass are used to count signal and background events after all selection cuts. The upper limits on the anomalous flavor changing neutral current tq gamma couplings are found to be lambda(q) < 0.01 at the future circular hadron electron collider for L-int - 100 fb(-1) with the fast simulation of detector effects. Signal significance depending on the couplings.q is analyzed and an enhanced sensitivity is found to the branching ratio BR(t -> q gamma) at the future circular hadron electron collider when compared to the current experimental results.