Sifting composite from elementary models at FCCee and CePC

TL;DR

This paper proposes using correlations between Z decay signals and electroweak precision data at future colliders to distinguish between composite and elementary models of new physics, especially in the Higgs sector.

Contribution

It introduces a novel method to differentiate composite from elementary models using collider signals and precision measurements at future lepton colliders.

Findings

Correlation analysis can effectively distinguish model types.

Future colliders can serve as discovery machines for new physics.

Electroweak precision data enhances model discrimination.

Abstract

New Physics models with either an elementary or composite origin are often associated with a similar imprint in a direct search at colliders, case in point being the production of a light pseudoscalar in association with a monochromatic photon from the decay of a Z boson at future $e+e-$ colliders. We exploit the correlation between the discovery of a signal in the Z decays and electroweak precision measurements as a tool to distinguish a composite model from an elementary scalar one. Our results offer an appealing and rich physics case for future colliders and demonstrate how a lepton collider at the Z mass can be a discovery machine for new physics in the Higgs sector.