## Constraining the Z' Mass in 331 Models using Direct Dark Matter Detection    [PDF]

Stefano Profumo, Farinaldo S. Queiroz
We investigate a 331 extension of the Standard Model gauge sector which accommodates neutrino masses and where the lightest of the heavy neutrinos is a viable WIMP dark matter candidate. In this model, processes mediated by the additional $Z^{\prime}$ gauge boson set both the WIMP relic abundance and the scattering cross section of WIMPs off of nuclei. We calculate the WIMP relic abundance including the important effect of coannihilation across the heavy neutrino sector. We find that the recent XENON results put very stringent bounds on the mass of the extra gauge boson, $M_{Z^{\prime}} > 1.6$ TeV, for WIMPs lighter than 1 TeV. Finally, we comment on how our bounds on the $Z^{\prime}$ mass impact generic 331-like models and on implications for LHC phenomenology.
View original: http://arxiv.org/abs/1307.7802