Mono-X Versus Direct Searches: Simplified Models for Dark Matter at the LHC

TL;DR

This paper evaluates the LHC's ability to detect dark matter using simplified models focusing on mono-X final states, comparing their effectiveness to direct mediating particle searches, and identifying scenarios where mono-X is most promising.

Contribution

It provides a comprehensive comparison of mono-X and direct searches for dark matter at the LHC using simplified models, highlighting cases where mono-X searches are most effective.

Findings

Direct searches generally outperform mono-X searches.

Mono-X searches are most effective in inelastic DM, two Higgs doublet, and squark-mediated models with compressed spectra.

Certain parameter regions favor mono-X detection over direct searches.

Abstract

We consider simplified models for dark matter (DM) at the LHC, focused on mono-Higgs, -Z, or -b produced in the final state. Our primary purpose is to study the LHC reach of a relatively complete set of simplified models for these final states, while comparing the reach of the mono-X DM search against direct searches for the mediating particle. We find that direct searches for the mediating particle, whether in di-jets, jets+MET, multi-b+MET, or di-boson+MET, are usually stronger. We draw attention to the cases that the mono-X search is strongest, which include regions of parameter space in inelastic DM, two Higgs doublet, and squark mediated production models with a compressed spectrum.