Subleading Higgs effects at lepton colliders

TL;DR

This paper investigates subtle Higgs-related effects in standard model processes at lepton colliders, demonstrating their significance at high energies through augmented perturbation theory and detailed calculations.

Contribution

It introduces an augmented perturbation theory approach to quantify subleading Higgs effects at next-to-leading order in lepton collider processes.

Findings

Deviations in $e^-e^+ o far{f}$ appear at electroweak NNLO in fixed order but are relevant at TeV scales in resummed calculations.

Subleading Higgs effects can be significant at future high-energy lepton colliders.

The formalism allows for precise predictions of Higgs contributions in collider processes.

Abstract

Subtle field-theoretical effects suggest the presence of additional Higgs contributions in standard model processes. This has been supported by electroweak lattice calculation, e.\ g.\ for vector boson scattering. These effects can be included in perturbation theory by a suitable augmentation. We use such augmented perturbation theory to determine the impact at next-to-leading order at lepton colliders, from LEP to future machines such as FCC, in collisions with fermion-antifermion final states. After providing the formal background, we outline the calculational procedure, showing that in the fully exclusive process $e^-e^+\to f\bar{f}$ deviations only occur in fixed order at electroweak NNLO, but become relevant at the TeV scale already in resummed tree-level calculations. We discuss further processes where deviations are expected already at fixed-order NLO.