Vector-like quarks coupling discrimination at the LHC and future hadron colliders

TL;DR

This paper proposes a method to distinguish the chiral nature of vector-like quarks at the LHC and future colliders by analyzing top quark polarization, aiding in understanding new physics models.

Contribution

It introduces a novel approach to discriminate left- and right-handed couplings of vector-like quarks using top polarization measurements at current and future colliders.

Findings

Effective discrimination of quark chiralities at the LHC.

Enhanced sensitivity at 33 and 100 TeV colliders.

Potential to narrow down new physics scenarios.

Abstract

The existence of new coloured states with spin one-half, i.e. extra-quarks, is a striking prediction of various classes of new physics models. Should one of these states be discovered during the 13 TeV runs of the LHC or at future high energy hadron colliders, understanding its properties will be crucial in order to shed light on the underlying model structure. Depending on the extra-quarks quantum number under SU(2)L, their coupling to Standard Model quarks and bosons have either a dominant left- or right-handed chiral component. By exploiting the polarisation properties of the top quarks arising from the decay of pair-produced extra quarks, we show how it is possible to discriminate among the two hypothesis in the whole discovery range currently accessible at the LHC, thus effectively narrowing down the possible interpretations of a discovered state in terms of new physics scenarios. Moreover, we estimate the discovery and discrimination power of future prototype hadron colliders with centre of mass energies of 33 and 100 TeV.