Probing Top Quark FCNC tqgamma and tqZ Couplings at Future Electron-Proton Colliders

TL;DR

This paper investigates potential flavor changing neutral current interactions involving the top quark at future electron-proton colliders, aiming to identify signals of new physics beyond the Standard Model through effective coupling analysis.

Contribution

It provides a detailed analysis of tqgamma and tqZ FCNC interactions at future colliders using an effective Lagrangian framework, including cross section calculations and sensitivity estimates.

Findings

Cross sections depend on coupling parameters lambda_q and kappa_q.

Sensitivity to FCNC couplings improves with higher luminosity.

Contour plots illustrate the attainable parameter space for different significance levels.

Abstract

The top quark flavor changing neutral current (FCNC) processes are extremely suppressed within the Standard Model (SM) of particle physics. However, they could be enhanced in a new physics model Beyond the Standard Model (BSM). The top quark FCNC interactions would be a good test of new physics at present and future colliders. Within the framework of the BSM models, these interactions can be described by an effective Lagrangian. In this work, we study tqgamma and tqZ effective FCNC interaction vertices through the process e-p->e-Wq+X at future electron proton colliders, projected as Large Hadron electron Collider (LHeC) and Future Circular Collider-hadron electron (FCC-he). The cross sections for the signal have been calculated for different values of parameters lambda_q for tqgamma vertices and kappa_q for $tqZ$ vertices. Taking into account the relevant background we estimate the attainable range of signal parameters as a function of the integrated luminosity and present contour plots of couplings for different significance levels including detector simulation.