Top quark anomalous FCNC production via $tqg$ couplings at FCC-hh

Abstract

We investigate the top quark anomalous Flavor Changing Neutral Current (FCNC) $tqg$ interactions to probe limits on the couplings $\hat{I}{\P }_c$ and $\hat{I}{\P }_u$ through the $qg\to l\hat{I}½b$ signal suprocess at FCC-hh collider with center of mass energy of 100 TeV. To separate signal from relevant Standard Model background processes, selection criteria based on Boosted Decision Trees (BDT) is used with a set of useful kinematic variables. The sensitivities on the anomalous top FCNC couplings $\hat{I}{\P }_u$ and $\hat{I}{\P }_c$ are found to be $1.239\times 10^{-4}$ and $1.149\times 10^{-4}$ for FCC-hh with $L_{int}$=10 ab${}^{-1}$ at 95 \% C.L. including realistic detector effects of the FCC-hh baseline detector, respectively. The branchings $BR(t\to ug)$ and $BR(t\to cg)$ converted from obtained limits for FCNC couplings are at the order of $10^{-7}$ which is at least one order of magnitude better than the projected limits of HL-LHC with $L_{int}$= 3 ab${}^{-1}$.

17 pages, 9 figures, 2 tables, to appear in Phys. Rev. D