Simplified Models for Dark Matter Face their Consistent Completions

TL;DR

This paper examines the limitations of simplified dark matter models with pseudoscalar mediators, highlighting how they differ from fully gauge-invariant theories and affect LHC search strategies.

Contribution

It demonstrates the significant phenomenological differences between simplified models and complete gauge-invariant theories for dark matter, especially in collider search contexts.

Findings

Simplified models deviate from gauge-invariant completions in key physics aspects.

Resonant mono-Z searches are competitive with mono-jet analyses at 13 TeV LHC.

Implications for dark matter search strategies at colliders.

Abstract

Simplified dark matter models have been recently advocated as a powerful tool to exploit the complementarity between dark matter direct detection, indirect detection and LHC experimental probes. Focusing on pseudoscalar mediators between the dark and visible sectors, we show that the simplified dark matter model phenomenology departs significantly from that of consistent ${SU(2)_{\mathrm{L}} \times U(1)_{\mathrm{Y}}}$ gauge invariant completions. We discuss the key physics simplified models fail to capture, and its impact on LHC searches. Notably, we show that resonant mono-Z searches provide competitive sensitivities to standard mono-jet analyses at $13$ TeV LHC.