Non-Minimal Dark Sectors: Mediator-Induced Decay Chains and Multi-Jet Collider Signatures

TL;DR

This paper explores how mediator-induced decay chains in multi-component dark sectors can produce distinctive multi-jet signatures at colliders, offering a new avenue for dark matter detection beyond traditional searches.

Contribution

It introduces the concept that mediators can cause decay chains within multi-component dark sectors, leading to unique collider signatures not previously emphasized.

Findings

Multi-jet signatures are viable and not excluded by current searches.

Dark decay chains can produce observable multi-jet events at colliders.

Parameter space exists where these signatures are detectable with future experiments.

Abstract

A preponderance of astrophysical and cosmological evidence indicates that the universe contains not only visible matter but also dark matter. In order to suppress the couplings between the dark and visible sectors, a standard assumption is that these two sectors communicate only through a mediator. In this paper we make a simple but important observation: if the dark sector contains multiple components with similar quantum numbers, then this mediator also generically gives rise to dark-sector decays, with heavier dark components decaying to lighter components. This in turn can even give rise to relatively long dark decay chains, with each step of the decay chain also producing visible matter. The visible byproducts of such mediator-induced decay chains can therefore serve as a unique signature of such scenarios. In order to examine this possibility more concretely, we examine a scenario in which a multi-component dark sector is connected through a mediator to Standard-Model quarks. We then demonstrate that such a scenario gives rise to multi-jet collider signatures, and we examine the properties of such jets at both the parton and detector levels. Within relatively large regions of parameter space, we find that such multi-jet signatures are not excluded by existing monojet and multi-jet searches. Such decay cascades therefore represent a potential discovery route for multi-component dark sectors at current and future colliders.