Bounds on Dark Matter Interactions with Electroweak Gauge Bosons

TL;DR

This paper derives model-independent bounds on dark matter interactions with electroweak gauge bosons using collider, indirect detection, and Z boson width data, constraining light dark matter scenarios.

Contribution

It provides the first comprehensive, model-independent bounds on dark matter-electroweak interactions within an effective field theory framework.

Findings

Limits on the UV scale reach weak scale values for most operators.

Light dark matter below Z mass cannot interact solely with electroweak bosons.

Additional operators or dark sector complexity are needed for light dark matter.

Abstract

We investigate scenarios in which dark matter interacts with the Standard Model primarily through electroweak gauge bosons. We employ an effective field theory framework wherein the Standard Model and the dark matter particle are the only light states in order to derive model-independent bounds. Bounds on such interactions are derived from dark matter production by weak boson fusion at the LHC, indirect detection searches for the products of dark matter annihilation and from the measured invisible width of the $Z^0$. We find that limits on the UV scale, $\Lambda$, reach weak scale values for most operators and values of the dark matter mass, thus probing the most natural scenarios in the WIMP dark matter paradigm. Our bounds suggest that light dark matter ($m_{\chi}\lsim m_Z/2$ or $m_{\chi}\lsim 100-200\gev$, depending on the operator) cannot interact only with the electroweak gauge bosons of the Standard Model, but rather requires additional operator contributions or dark sector structure to avoid overclosing the universe.