QCD next-to-leading-order predictions matched to parton showers for vector-like quark models

TL;DR

This paper provides next-to-leading-order QCD predictions for vector-like quark production processes, enhancing the accuracy of theoretical models used in LHC searches for new physics beyond the Standard Model.

Contribution

It introduces comprehensive NLO QCD calculations for vector-like quark pair and single production, including associated boson production, for the first time in this context.

Findings

First-time NLO predictions for vector-like quark processes.

Enhanced precision in total and differential cross sections.

Potential for improved experimental limits on vector-like quarks.

Abstract

Vector-like quarks are featured by a wealth of beyond the Standard Model theories and are consequently an important goal of many LHC searches for new physics. Those searches, as well as most related phenomenological studies, however rely on predictions evaluated at the leading-order accuracy in QCD and consider well-defined simplified benchmark scenarios. Adopting an effective bottom-up approach, we compute next-to-leading-order predictions for vector-like-quark pair-production and single production in association with jets, with a weak or with a Higgs boson in a general new physics setup. We additionally compute vector-like-quark contributions to the production of a pair of Standard Model bosons at the same level of accuracy. For all processes under consideration, we focus both on total cross sections and on differential distributions, most these calculations being performed for the first time in our field. As a result, our work paves the way to precise extraction of experimental limits on vector-like quarks thanks to an accurate control of the shapes of the relevant observables and emphasize the extra handles that could be provided by novel vector-like-quark probes never envisaged so far