Limits on strong FCNC top couplings at the LHC

TL;DR

This paper improves limits on strong flavor-changing neutral current top couplings at the LHC by using advanced simulations and considering additional processes, highlighting potential for more stringent future constraints.

Contribution

It introduces a next-to-leading order generator for analyzing FCNC top couplings and explores the impact of including additional processes and final states on the limits.

Findings

Limits on FCNC couplings can be improved with NLO simulations.

Including the $pp o tj$ process enhances sensitivity.

Adding an extra jet in the analysis offers further improvements.

Abstract

The best limit on the strong FCNC anomalous couplings was obtained using the direct top production process at the Large Hadron Collider by the ATLAS collaboration. We perform a similar analysis but using a next-to-leading order generator, MEtop. We then show how the limits could be improved if the FCNC single top process $pp \to tj$ would be included as signal. Finally we discuss a slightly modified analysis with an extra hard jet in the final state.