Constraints on Z' models from LHC dijet searches and implications for   dark matter
  We analyse a combination of ATLAS and CMS searches for dijet resonances at run I and run II, presenting the results in a way that can be easily applied to a generic Z' model. As an illustrative example, we consider a simple model of a Z' coupling to quarks and dark matter. We first study a benchmark case with fixed couplings and then focus on the assumption that the Z' is responsible for setting the dark matter relic abundance. Dijet constraints place significant bounds on this scenario, allowing us to narrow down the allowed range of dark matter masses for given Z' mass and width. 
Malcolm Fairbairn, John Heal, Felix Kahlhoefer and Patrick Tunney
hep-ph hep-ex