Testing ATLAS Z+MET Excess with LHC Run 2

TL;DR

This paper evaluates various new physics models explaining the ATLAS Z+MET excess, analyzing their consistency with LHC Run 1 and Run 2 data, and finds light squark models fit better than heavy gluino ones.

Contribution

It provides a comprehensive comparison of proposed models against recent LHC results, highlighting which models remain viable.

Findings

Heavy gluino models show tension between 8 TeV and 13 TeV data.

Light squark models better fit both Run 1 and Run 2 results.

Overall, models with light squarks are more consistent with observed data.

Abstract

The ATLAS collaboration reported a 3sigma excess in the search of events containing on-Z dilepton, jets, and large missing momentum (MET) in the 8 TeV LHC run. Motivated by this excess, many models of new physics have been proposed. Recently, the ATLAS and CMS collaborations reported new results for similar Z+MET channels in the 13 TeV run. In this paper, we comprehensively discuss the consistency between the proposed models and the LHC results of Run 1 and Run 2. We find that in models with heavy gluino production, there is generically some tension between the 8 TeV and 13 TeV results. On the other hand, models with light squark production provide relatively better fitting to both results.