Dark Matter Search at a Linear Collider: Effective Operator Approach

TL;DR

This paper evaluates the potential of the International Linear Collider to detect dark matter via effective operator formalism, showing it can probe higher energy scales than current experiments and explore new parameter space.

Contribution

It provides a model-independent analysis of dark matter detection prospects at the ILC using effective operators, extending current bounds significantly.

Findings

ILC can probe mbda up to 1-1.2 TeV at 250 GeV

With 1 TeV energy and polarization, reach extends to 3-4 TeV

ILC can explore parameter space consistent with current LHC and direct detection bounds

Abstract

Experiments at electron-positron colliders can search for dark matter particle pair-production in association with a photon. We estimate the sensitivity of this search at the proposed International Linear Collider (ILC), under a variety of run scenarios. We employ the effective operator formalism to provide a quasi-model-independent theoretical description of the signal, and present the reach of the ILC in terms of the scale \Lambda suppressing the dark matter-electron coupling operator. We find that at the 250 GeV center-of-mass energy, the ILC can probe \Lambda up to 1-1.2 TeV, a factor of 2.5-3 above the best current bounds from LEP-2. With 1 TeV energy and polarized beams, the reach can be extended to 3-4 TeV. The ILC can discover this signature even if annihilation to electrons provides only a small fraction of the total dark matter annihilation rate in the early universe. We also argue that large regions of parameter space allowed by current LHC and direct detection bounds will be accessible at the ILC.