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

## TL;DR

This paper explores the potential to detect anomalous top quark FCNC interactions at the FCC-hh collider using advanced analysis techniques, achieving significantly improved sensitivity over previous collider experiments.

## Contribution

It introduces a method to probe top quark FCNC $tqg$ couplings at FCC-hh with boosted decision trees, providing more stringent limits than HL-LHC.

## Key findings

- Sensitivity on $ zeta_u$ and $ zeta_c$ couplings at $10^{-4}$ level.
- FCNC top decay branching ratios constrained to order $10^{-7}$.
- Significantly better limits than HL-LHC projections.

## Abstract

We investigate the top quark anomalous Flavor Changing Neutral Current (FCNC) $tqg$ interactions to probe limits on the couplings $\zeta_c$ and $\zeta_u$ through the $qg \to l\nu b$ 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 $\zeta_u$ and $\zeta_c$ are found to be $1.239\times10^{-4}$ and $1.149\times10^{-4}$ 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 $BR (t \to c g)$ 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$^{-1}$.