Boosting top partner searches in composite Higgs models

Abstract

Fermionic third generation top partners are generic in composite Higgs models. They are likely to decay into third generation quarks and electroweak bosons. We propose a novel cut-and-count-style analysis in which we cross correlate the model-dependent single and model-independent pair production processes for the top partners ${X}_{5/3}$ and $B$. In the class of composite Higgs models we study, ${X}_{5/3}$ is very special as it is the lightest exotic fermion. A constraint on the mass of ${X}_{5/3}$ directly extends to constrains on all top partner masses. By combining jet substructure methods with conventional reconstruction techniques we show that in this kind of final state a smooth interpolation between the boosted and unboosted regime is possible. We find that a reinterpretation of existing searches can improve bounds on the parameter space of composite Higgs models. Further, at 8 TeV a combined search for ${X}_{5/3}$ and $B$ in the $l+\text{jets}$ final state can be more sensitive than a search involving same-sign dileptons.