Probing the Top-Higgs Sector with Composite Higgs Models at Present and Future Hadron Colliders

TL;DR

This paper investigates top-Higgs production processes within minimal Composite Higgs Models at current and future hadron colliders, analyzing phenomenology, potential signals, and the importance of various vertices and decay channels.

Contribution

It provides a detailed phenomenological analysis of $t\bar{t}h$ and $t\bar{t}hh$ production in composite Higgs models, including resonance effects and decay channels at different collider energies.

Findings

Resonant and non-resonant production channels show complementary sensitivities.

The three-body decay $W^+ W^- t$ becomes significant in certain parameter regions.

Higher energy colliders enhance the detection prospects of top partners and decay channels.

Abstract

We study the production of $t{\bar t}h$ and $t{\bar t}hh$ at hadron colliders, in the minimal Composite Higgs Models, based on the coset $SO(5)/SO(4)$. We explore the fermionic representations ${\bf 5}$ and ${\bf 14}$. A detailed phenomenological analysis is performed, covering the energy range of the LHC and its High Luminosity upgrade, as well as that of a future 100 TeV hadron collider. Both resonant and non-resonant production are considered, stressing the interplay and complementary interest of these channels with each other and double Higgs production. We provide sets of representative points with detailed experimental outcomes in terms of modification of the cross sections as well as resonance masses and branching ratios. For non-resonant production, we gauge the relative importance of Yukawa, Higgs trilinear, and contact $t\bar{t}hh$ vertices to these processes, and consider the prospect for distinguishing the fermion representations from each other and from the Standard Model. In the production of top partners, we find that the three-body decay channel $W^+ W^- t$ becomes significant in certain regions of parameter space having a degenerate spectrum, and is further enhanced with energy. This motivates both higher energy machines as well as the need to go beyond the current analysis performed for the searches for these resonances.