Fermionic Effective Operators and Higgs Production at a Linear Collider

TL;DR

This paper investigates how dimension six fermionic operators could significantly alter Higgs production rates at future linear colliders, even under existing experimental constraints, highlighting potential deviations from Standard Model predictions.

Contribution

It analyzes the impact of fermionic effective operators on Higgs production at linear colliders, including constraints and comparison with bosonic operators, revealing possible sizable deviations.

Findings

Fermionic operators can enhance Higgs production cross-sections.

Existing precision measurements constrain operator coefficients.

Substantial deviations from SM are still possible within constraints.

Abstract

We study the possible contributions of dimension six operators containing fermion fields to Higgs production at a 500 GeV or 1 TeV $e^+e^-$ linear collider. We show that -- depending on the production mechanism -- the effects of such operators can be kinematically enhanced relative to Standard Model (SM) contributions. We determine constraints on the operator coefficients implied by existing precision electroweak measurements and the scale of neutrino mass. We find that even in the presence of such constraints, substantial deviations from SM Higgs production cross-sections are possible. We compare the effects of fermionic operators with those associated with purely bosonic operators that have been previously discussed in the literature.