Precise predictions for electroweak $t\bar t$ production at the LHC in models with flavour non-diagonal $Z'$ boson couplings and $W'$ bosons

TL;DR

This paper presents a detailed recalculation of electroweak top-quark pair production at the LHC within models featuring non-diagonal $Z'$ and $W'$ boson couplings, including NLO QCD corrections and interference effects, with results applicable up to 100 TeV.

Contribution

It introduces a comprehensive NLO QCD calculation of $tar{t}$ production in models with flavour non-diagonal $Z'$ and $W'$ bosons, incorporating non-resonant effects and interference with the Standard Model.

Findings

Significant impact of non-resonant contributions on $tar{t}$ cross sections.

Enhanced predictions for $tar{t}$ production at energies up to 100 TeV.

Quantitative analysis of interference effects between new physics and Standard Model.

Abstract

We report on our re-calculation of electroweak top-quark pair production in Standard Model extensions with extra heavy neutral and charged spin-1 particles at the LHC with substantial improvements. In particular, we allow for flavour--non-diagonal $Z'$ couplings and take into account non-resonant production in the Standard Model and beyond. As in our previous work we include NLO QCD corrections and match to parton showers with the POWHEG method fully taking into account the Standard Model and new physics interference effects. We consider the Sequential Standard Model, the Topcolour model as well as the Third Family Hypercharge Model featuring non-flavour diagonal $Z'$ couplings which has been proposed to explain the anomalies in $B$ decays. Numerical results for $t\bar{t}$ cross sections at hadron colliders with $\sqrt{s}$ of up to 100 TeV are presented. We also investigate the numerical impact of the new non-resonant contributions.