# Search for single production of a top quark partner via the $T\to th$ and $h\to WW^{\ast}$ channels at the LHC

## TL;DR

This paper investigates the potential to discover or exclude vector-like top quark partners at the LHC through specific decay channels, providing sensitivity projections for current and future collider runs within a simplified and a realistic composite Higgs model.

## Contribution

It introduces a search strategy for top quark partners via the $T o th$ and $h o WW^*$ channels, with detailed sensitivity and exclusion limits for LHC and HL-LHC, including a realistic composite Higgs model interpretation.

## Key findings

- Projected exclusion limits on ($m_T,g^*$) at LHC and HL-LHC
- Discovery prospects for top quark partners in specified channels
- Sensitivity analysis in terms of cross section times branching ratio

## Abstract

Many scenarios of physics beyond the Standard Model that address the hierarchy problem also predict the existence of vector-like top quark partners, which are generally expected around the TeV scale. In this paper, we propose to search for a vector-like top quark partner with charge $2/3$ in a simplified model including only two free parameters, the coupling constant $g^{\ast}$ and top quark partner mass $m_T$. We investigate the observability of the top quark partner through the process $pp \to T(\to th)j\to t(\to b W^+\to b \ell^{+} \nu_{\ell})h( \to WW^{\ast}\to \ell^{+}\nu\ell^{-}\bar{\nu}) j$, where $T$ is the heavy top quark partner and $h$ the SM-like Higgs boson, at the Large Hadron Collider (LHC). The discovery prospects and exclusion limits on the parameter plane defined by ($m_T,g^{\ast}$) are obtained for the already scheduled LHC runs as well as at the future High-Luminosity~LHC (HL-LHC). The constraints and projected sensitivities are also interpreted in a realistic model, i.e., the minimal Composite Higgs Model with singlet top quark partners. We finally also analyze the projected sensitivity in terms of the production cross section times branching fraction at the (HL-)LHC.