Recommendations of the LHC Dark Matter Working Group: Comparing LHC searches for heavy mediators of dark matter production in visible and invisible decay channels

TL;DR

This paper discusses how to compare LHC searches for dark matter mediators in visible and invisible channels, extending models to include lepton couplings and analyzing relic density calculations.

Contribution

It provides a framework for comparing different LHC dark matter search strategies and extends simplified models to include lepton interactions.

Findings

Guidelines for comparing mono-X and mediator signals

Extension of simplified models to include lepton couplings

Analysis of relic density calculations and related issues

Abstract

Weakly-coupled TeV-scale particles may mediate the interactions between normal matter and dark matter. If so, the LHC would produce dark matter through these mediators, leading to the familiar "mono-X" search signatures, but the mediators would also produce signals without missing momentum via the same vertices involved in their production. This document from the LHC Dark Matter Working Group suggests how to compare searches for these two types of signals in case of vector and axial-vector mediators, based on a workshop that took place on September 19/20, 2016 and subsequent discussions. These suggestions include how to extend the spin-1 mediated simplified models already in widespread use to include lepton couplings. This document also provides analytic calculations of the relic density in the simplified models and reports an issue that arose when ATLAS and CMS first began to use preliminary numerical calculations of the dark matter relic density in these models.