A clean signal for a top-like isosinglet fermion at the Large Hadron Collider

TL;DR

This paper predicts a distinctive, background-free signal at the LHC for detecting a top-like, charge +2/3 vectorlike isosinglet fermion through its decay into tops and Higgs bosons, especially via the Higgs to bar{b} channel.

Contribution

It introduces a novel, clean detection channel for a top-like isosinglet fermion at the LHC, focusing on its decay into tops and Higgs bosons via Yukawa interactions.

Findings

Potential for a background-free signal at the LHC

Distinctive decay signature involving tops and Higgs bosons

Feasibility of detecting the fermion through Higgs to bar{b} decay

Abstract

We predict a clean signal at the Large Hadron Collider ($\sqrt s)$=14 TeV for a scenario where there is a top-like, charge +2/3 vectorlike isosinglet fermion. Such a quark, via mixing with the standard model top, can undergo decays via both flavour-changing Z-boson coupling and flavour-changing Yukawa interactions. We concentrate on the latter channel, and study the situation where, following its pair-production, the heavy quark pair gives rise to two tops and two Higgs boson. We show that the case where each Higgs decays in the $b\bar{b}$ channel, there can be a rather distinct and background-free signal that can unveil the existence of the vectorlike isosinglet quark of this kind.