Contact Interactions Probe Effective Dark Matter Models at the LHC

TL;DR

This paper demonstrates that quark contact interaction limits at the LHC can provide stronger constraints on dark matter models than direct dark matter pair production searches, by relating effective vertices in a unified framework.

Contribution

It establishes a connection between quark contact interactions and dark matter production vertices, enabling more stringent limits on dark matter couplings from existing contact interaction data.

Findings

Quark contact interaction limits surpass direct DM search limits in constraining models.

Effective vertices for DM and quark contact interactions are related, allowing translation of limits.

LHC data provides stronger bounds on DM couplings via contact interactions.

Abstract

Effective field theories provide a simple framework for probing possible dark matter (DM) models by reparametrising full interactions into a reduced number of operators with smaller dimensionality in parameter space. In many cases these models have four particle vertices, e.g. qqXX, leading to the pair production of dark matter particles, X, at a hadron collider from initial state quarks, q. In this analysis we show that for many fundamental DM models with s-channel DM couplings to qq-pairs, these effective vertices must also produce quark contact interactions (CI) of the form qqqq. The respective effective couplings are related by the common underlying theory which allows one to translate the upper limits from one coupling to the other. We show that at the LHC, the experimental limits on quark contact interactions give stronger translated limits on the DM coupling than the experimental searches for dark matter pair production.