Resonating new physics: Dijet signatures in the extended scalar frontier at the HL-LHC

Abstract

The Standard Model's unaddressed questions, notably the hierarchy problem, motivate searches for additional scalar states. We explore dijet invariant mass distributions as a probe of an extended scalar sector in the Minimal Dilaton Model, focusing on dilaton production via quark−antiquark annihilation. We compare the smoothly falling QCD spectrum with potential resonance peaks from this dilaton-mediated process. Though the signal cross-section is intrinsically smaller than the QCD background, all distributions are normalised and scaled to HL-LHC conditions (√s = 14 TeV, ℒ = 3000 fb⁻¹) for direct kinematic shape comparison. The resulting spectrum shows the QCD background's characteristic fall, while the signal manifests as resonances at nominal dilaton masses. This study provides proof-of-principle for using precision dijet shape analyses to find rare scalar resonances signalling new physics via specific production channels.