Search for Top Quark FCNC Couplings in Z' Models at the LHC and CLIC

TL;DR

This paper investigates the potential to detect top quark flavor-changing neutral current couplings mediated by Z' bosons at the LHC and CLIC, providing cross section predictions and exploring parameter space for new physics signals.

Contribution

It offers the first detailed analysis of top FCNC couplings via Z' models at both LHC and CLIC energies, including cross section calculations and parameter space exploration.

Findings

Single top FCNC production cross sections are 0.38 fb at 7 TeV and 1.76 fb at 14 TeV LHC.

Resonance production cross sections at CLIC are 27.96 fb at 1 TeV and 0.91 fb at 3 TeV.

Results highlight the importance of flavor tagging in probing Z' mediated FCNC processes.

Abstract

The top quark is the heaviest particle to date discovered, with a mass close to the electroweak symmetry breaking scale. It is expected that the top quark would be sensitive to the new physics at the TeV scale. One of the most important aspects of the top quark physics can be the investigation of the possible anomalous couplings. Here, we study the top quark flavor changing neutral current (FCNC) couplings via the extra gauge boson Z' at the Large Hadron Collider (LHC) and the Compact Linear Collider (CLIC) energies. We calculate the total cross sections for the signal and the corresponding Standard Model (SM) background processes. For an FCNC mixing parameter x=0.2 and the sequential Z' mass of 1 TeV, we find the single top quark FCNC production cross sections 0.38(1.76) fb at the LHC with sqrt{s_{pp}}=7(14) TeV, respectively. For the resonance production of sequential Z' boson and decays to single top quark at the Compact Linear Collider (CLIC) energies, including the initial state radiation and beamstrahlung effects, we find the cross section 27.96(0.91) fb at sqrt{s_{e^{+}e^{-}}}=1(3) TeV, respectively. We make the analysis to investigate the parameter space (mixing-mass) through various Z' models. It is shown that the results benefit from the flavor tagging.