Reconstruction of Inert Doublet Scalars at the International Linear Collider

TL;DR

This paper investigates how the inert doublet model's extra scalar bosons can be detected at the ILC, focusing on their signatures, mass determination, and the model's dark matter candidate, especially in regions inaccessible to the LHC.

Contribution

It provides a simulation-based analysis of inert doublet scalars at the ILC, highlighting detection prospects and mass measurement strategies for the first time.

Findings

Parameter regions undetectable at the LHC can be probed at the ILC.

Distinctive signatures of inert scalars can be identified over the standard model background.

The study offers methods to determine the scalar masses at the ILC.

Abstract

We study collider signatures for extra scalar bosons in the inert doublet model at the international linear collider (ILC). The inert doublet model is a simple extension of the standard model by introducing an additional isospin-doublet scalar field which is odd under an unbroken Z_2 symmetry. The model predicts four kinds of Z_2-odd scalar bosons, and the lightest of them becomes stable and a candidate of the dark matter as long as it is electrically neutral. Taking into account the constraints from various theoretical and phenomenological conditions, we perform a simulation study for the distinctive signatures of the extra scalars over the standard-model background contributions at the ILC with the center-of-mass energy of sqrt{s} = 250 GeV and 500 GeV. We further discuss observables for determination of the mass of the scalars. We find that the parameter regions which cannot be detected at the large hadron collider can be probed at the ILC.