M(DM) vs M(Z') - Vector mediator model, dijet and dilepton searches

Observed and expected 95% CL exclusion regions in the mmed−mDM plane for dijet [JHEP 08 (2018) 130, JHEP 05 (2020) 033, JHEP 01 (2018) 097] and dilepton [JHEP 07 (2021) 208] searches from CMS in the vector mediator model. Following the recommendation of the LHC DM Working Group [Phys. Dark Univ. 27 (2020) 100365, Phys. Dark Univ. 26 (2019) 100377], the exclusions are computed for a universal quark coupling of gq= 0.1, lepton coupling gℓ= 0.01 (upper) and gℓ= 0.1 (lower), and for a DM coupling of gDM= 1.0. The resonant annihilation constraint mDM=0.5mmed is plotted as the gray dashed line, while the constraint from the thermal-relic density (Ωh2> 0.12), obtained from WMAP [Astrophys. J. Suppl. 208 (2013) 20] and Planck [Astron. Astrophys. 594 (2016) A13], is plotted as the gray solid line. It should also be noted that the absolute exclusion of the different searches as well as their relative importance, will strongly depend on the chosen coupling and model scenario. Therefore, the exclusion regions, thermal-relic density contours, and unitarity curve shown in this plot are not applicable to other choices of coupling values or models.