Probing triple Higgs couplings of the Two Higgs Doublet Model at Linear Collider

TL;DR

This paper investigates how future linear colliders can probe triple Higgs couplings within the Two Higgs Doublet Model by analyzing various double Higgs production channels and their distinctive signatures.

Contribution

It provides a detailed analysis of double Higgs production processes sensitive to triple Higgs couplings in the Two Higgs Doublet Model at linear colliders.

Findings

Certain processes are highly sensitive to triple Higgs couplings.

Distinctive gamma-ray signatures can be observed in specific model limits.

The study helps reconstruct the scalar potential of the model.

Abstract

We study double Higgs production at the future Linear Collider in the framework of the Two Higgs Doublet Models through the following channels: $e^+e^- \to \Phi_i \Phi_j Z$, $\Phi_i=h^0, H^0, A^0, H^\pm$. All these processes are sensitive to triple Higgs couplings. Hence observations of them provide information on the triple Higgs couplings that help reconstructing the scalar potential. We also discuss the double Higgs-strahlung $e^+e^- \to h^0 h^0 Z$ in the decoupling limit where $h^0$ mimics the SM Higgs boson. The processes $e^+e^- \to h^0 h^0 Z$ and $e^+e^- \to h^0 H^0 Z$ are also discussed in the fermiophobic limit where distinctive signatures such as $4\gamma +X$, $2\gamma +X$ and $6\gamma +X$ are expected in the Type-I Two Higgs Doublet Model.