LHC signatures of a Z' mediator between dark matter and the SU(3) sector

In this paper, we study the experimental signatures of a gluophilic $Z^{\mathrm{\prime }}$ at the LHC, in particular through the analysis of three jets or four tops events. The $Z^{\mathrm{\prime }}$ couples to gluons through dimension six operators and the parameter space is constrained with experimental searches released at 7 and 8 $\mathrm{T}\mathrm{e}\mathrm{V}$ by CMS along these two different channels. Existing constraints coming from the study of dark matter where the $Z^{\mathrm{\prime }}$ represents a possible mediator between the latter and the Standard Model are also included for comparison. Prospects at $\sqrt{s}=13$ TeV allow us to evaluate for which values of the parameter space a gluophilic $Z^{\mathrm{\prime }}$ could be discovered during the next run of the LHC. In particular, we show that the analysis of the three jets invariant mass could provide a clear signal ($>5\sigma$) for masses of the $Z^{\mathrm{\prime }}$ above 300 $\mathrm{G}\mathrm{e}\mathrm{V}$. Four tops events bring in addition further discovery potential for heavy $Z^{\mathrm{\prime }}$ (above $\sim 2\mathrm{T}\mathrm{e}\mathrm{V}$). A combination of both signals in four top channels and three jets analyses during the next run of the LHC could thus provide a clear signal of the presence of a heavy gluophilic $Z^{\mathrm{\prime }}$.