# Blind Spots for Direct Detection with Simplified DM Models and the LHC

## TL;DR

This paper explores how certain dark matter models with suppressed direct detection signals can still be constrained by collider searches at the LHC, especially through combined analysis of multiple search channels.

## Contribution

It demonstrates that interference effects in simplified dark matter models create blind spots for direct detection, which can be constrained by collider data using combined search strategies.

## Key findings

- Collider limits can surpass direct detection in some parameter regions.
- Interference effects can suppress direct detection signals.
- Combined LHC searches effectively constrain models with blind spots.

## Abstract

Using the existing simplified model framework, we build several dark matter models which have suppressed spin-independent scattering cross section. We show that the scattering cross section can vanish due to interference effects with models obtained by simple combinations of simplified models. For weakly interacting massive particle (WIMP) masses $\gtrsim$10 GeV, collider limits are usually much weaker than the direct detection limits coming from LUX or XENON100. However, for our model combinations, LHC analyses are more competitive for some parts of the parameter space. The regions with direct detection blind spots can be strongly constrained from the complementary use of several Large Hadron Collider (LHC) searches like mono-jet, jets + missing transverse energy, heavy vector resonance searches, etc. We evaluate the strongest limits for combinations of scalar + vector, "squark" + vector, and scalar + "squark" mediator, and present the LHC 14 TeV projections.