Probing Higgs self-coupling of a classically scale invariant model in $e^+e^- \to Zhh$: Evaluation at physical point

TL;DR

This paper investigates the potential of future electron-positron colliders to probe the Higgs self-coupling in a classically scale invariant extension of the Standard Model, highlighting unique momentum-dependent features of the Higgs triple vertex.

Contribution

The study provides a comprehensive calculation of Higgs triple coupling effects, including missing one-loop contributions, in a minimal scale-invariant model using the process $e^+e^- o Zhh$.

Findings

Enhanced sensitivity to Higgs self-coupling at future colliders.

Identification of unique momentum dependence in the Higgs triple vertex.

Estimation of discovery and exclusion potential for the model.

Abstract

A classically scale invariant extension of the standard model predicts large anomalous Higgs self-interactions. We compute missing contributions in previous studies for probing the Higgs triple coupling of a minimal model using the process $e^+e^- \to Zhh$. Employing a proper order counting, we compute the total and differential cross sections at the leading order, which incorporate the one-loop corrections between zero external momenta and their physical values. Discovery/exclusion potential of a future $e^+e^-$ collider for this model is estimated. We also find a unique feature in the momentum dependence of the Higgs triple vertex for this class of models.