Resonant leptoquark at NLO with POWHEG

TL;DR

This paper develops a NLO Monte Carlo simulation for resonant leptoquark production via quark-lepton fusion at hadron colliders, enhancing precision and exploring detection prospects at the LHC and FCC-hh.

Contribution

It introduces the first NLO Monte Carlo generator for scalar leptoquark production via quark-lepton fusion, including decay and parton shower matching.

Findings

Differential distributions with higher-order effects analyzed

Theoretical uncertainties quantified

Impact on LHC and FCC-hh sensitivities assessed

Abstract

Recent progress in calculating lepton density functions inside the proton and simulating lepton showers laid the foundations for precision studies of resonant leptoquark production at hadron colliders. Direct quark-lepton fusion into a leptoquark is a novel production channel at the LHC that has the potential to probe a unique parameter space for large masses and couplings. In this work, we build the first Monte Carlo event generator for a full-fledged simulation of this process at NLO for production, followed by a subsequent decay using the POWHEG method and matching to the parton showers utilizing HERWIG. The code can handle all scalar leptoquark models with renormalisable quark-lepton interactions. We then comprehensively study the differential distributions, including higher-order effects, and asses the corresponding theoretical uncertainties. We also quantify the impact of the improved predictions on the projected (HL-)LHC sensitivities and initiate the first exploration of the potential at the FCC-hh. Our work paves the way toward performing LHC searches using this channel.