The LHC potential of Vector-like quark doublets

TL;DR

This paper investigates the LHC discovery potential for models with two vector-like quark doublets, highlighting unique signatures and production modes that differ from traditional searches, especially for TeV-scale masses.

Contribution

It provides a detailed analysis of the constraints and signatures of two vector-like quark doublets mixing with Standard Model quarks, including novel production and decay modes.

Findings

Single production of the heavier state can dominate over the lighter one.

Electroweak pair production surpasses QCD production at TeV-scale masses.

New signatures not covered by existing LHC searches.

Abstract

The existence of new vector-like quarks is often predicted by models of new physics beyond the Standard Model, and the development of discovery strategies at colliders is the object of an intense effort from the high-energy community. Our analysis aims at identifying the constraints on and peculiar signatures of simplified scenarios containing \textit{two} vector-like quark doublets mixing with \textit{any} of the SM quark generations. This scenario is a necessary ingredient of a broad class of theoretically motivated constructions. We focus on the two charge $2/3$ states $t_{1,2}^\prime$ that, due to their peculiar mixing patterns, feature new production and decay modes that are not searched for at the LHC: single production of the heavier state can dominate over the light one, while pair production via electroweak interactions overcomes the QCD one for masses at the TeV scale.