Inert Doublet Model and LEP II Limits

TL;DR

This paper explores how LEP II collider data constrains the inert doublet model, a minimal extension of the standard model with new scalar particles, and discusses implications for dark matter.

Contribution

It translates LEP II neutralino search results to set bounds on inert scalars in the inert doublet model, connecting collider constraints with dark matter viability.

Findings

LEP II data excludes significant parameter space of the inert doublet model.

The lightest inert particle remains a viable dark matter candidate.

Collider constraints complement dark matter search efforts.

Abstract

The inert doublet model is a minimal extension of the standard model introducing an additional SU(2) doublet with new scalar particles that could be produced at accelerators. While there exists no LEP II analysis dedicated for these inert scalars, the absence of a signal within searches for supersymmetric neutralinos can be used to constrain the inert doublet model. This translation however requires some care because of the different properties of the inert scalars and the neutralinos. We investigate what restrictions an existing DELPHI collaboration study of neutralino pair production can put on the inert scalars and discuss the result in connection with dark matter. We find that although an important part of the inert doublet model parameter space can be excluded by the LEP II data, the lightest inert particle still constitutes a valid dark matter candidate.