Open Access Publications from the University of California

## LHC Searches for Dark Matter and Exotic Resonances

• Author(s): Shimmin, Chase Owen
• et al.
Abstract

In this work, several phenomenological models for extending the Standard Model are presented, with an emphasis on providing a candidate dark matter particle.

These models are specifically designed as benchmark signals in two novel search channels proposed for LHC experiments: mono-$Z$ and mono-Higgs.

Searches for dark matter production in these newly-proposed channels are then conducted using data from $pp$ collisions at $\sqrt{s} = 8 \TeV$ recorded by the ATLAS detector.

In both cases, the observed measurements are consistent with the predicted Standard Model rates.

Therefore, upper limits are derived on the production cross sections of these dark matter models, which are also translated to limits on theoretical parameters specific to each model.

Lastly, a method of searching for hadronic resonances with masses in the 20--500 \GeV\ range at the LHC is described in the context of a minimal leptophobic $Z'$ extension to the Standard Model.

The feasibility of this search method is investigated assuming a dataset of 4 \ifb\ of $pp$ collisions in terms of the sensitivity to the $Z'$ coupling parameter.

These searches are expected to provide nontrivial limits on the $Z'$ model in regions that have been either only weakly constrained or never probed by direct measurements.