Constraining Dark Matter Interactions with Pseudoscalar and Scalar Mediators Using Collider Searches for Multi-jets plus Missing Transverse Energy

TL;DR

This paper demonstrates that multi-jet collider searches are more effective than mono-jet searches in constraining pseudoscalar and scalar dark matter mediators, especially in models explaining gamma-ray excesses, and emphasizes the importance of combined search strategies.

Contribution

It shows that multi-jet searches outperform mono-jet searches for pseudoscalar and scalar mediators and highlights the need for combined collider search approaches to better detect dark matter.

Findings

Multi-jet searches are more sensitive than mono-jet searches for certain dark matter mediators.

Current multi-jet searches constrain pseudoscalar interpretations of gamma-ray excesses.

Future LHC runs will fully explore the relevant parameter space for these models.

Abstract

The mono-jet search, looking for events involving missing transverse energy (MET) plus one or two jets, is the most prominent collider dark matter search. We show that multi-jet searches, which look for MET plus two or more jets, are significantly more sensitive than the mono-jet search for pseudoscalar- and scalar-mediated interactions. We demonstrate this in the context of a simplified model with a pseudoscalar interaction that explains the excess in GeV energy gamma rays observed by the Fermi Large Area Telescope. We show that multi-jet searches already constrain a pseudoscalar interpretation of the excess in much of the parameter space where the mass of the mediator (mA) is more than twice the dark matter mass (mDM). With the forthcoming run of the LHC at higher energies, the remaining regions of the parameter space where mA>2mDM will be fully explored. Furthermore, we highlight the importance of complementing the mono-jet final state with multi-jet final states to maximise the sensitivity of the search for the production of dark matter at colliders.