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

TL;DR

This paper investigates the LHC signatures of a gluophilic Z' mediator between dark matter and the Standard Model, analyzing three jets and four tops events to identify potential discovery channels at 13 TeV.

Contribution

It introduces a study of gluophilic Z' signatures at the LHC through dimension six operators, combining experimental constraints and future prospects for discovery.

Findings

Three jets invariant mass analysis can detect Z' above 300 GeV with >5σ significance.

Four top events enhance discovery potential for Z' above ~2 TeV.

Combining three jets and four tops channels improves detection prospects at 13 TeV.

Abstract

In this paper, we study the experimental signatures of a gluophilic $Z'$ at the LHC, in particular through the analysis of three jets or four tops events. The $Z'$ couples to gluons through dimension six operators and the parameter space is constrained with experimental searches released at 7 and 8 $\mathrm{TeV}$ by CMS along these two different channels. Existing constraints coming from the study of dark matter where the $Z'$ 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 $Z'$ 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 $Z'$ above 300 $\mathrm{GeV}$. Four tops events bring in addition further discovery potential for heavy $Z'$ (above $\sim 2~\mathrm{TeV}$). 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 $Z'$.