Search for new phenomena in final states with large jet multiplicities and missing transverse momentum with ATLAS using $\sqrt{s} =13$ TeV proton--proton collisions

TL;DR

This paper reports a search for new phenomena like supersymmetry in high-energy proton-proton collisions, focusing on events with many jets and missing transverse momentum, but finds no evidence of new physics and sets new exclusion limits.

Contribution

It introduces a search strategy for supersymmetric particles using high jet multiplicity and missing energy, extending previous mass exclusion limits at the LHC.

Findings

No excess above Standard Model expectations was observed.

Gluino masses up to 1400 GeV are excluded at 95% confidence level.

The analysis extends previous limits significantly.

Abstract

Results are reported of a search for new phenomena, such as supersymmetric particle production, that could be observed in high-energy proton--proton collisions. Events with large numbers of jets, together with missing transverse momentum from unobserved particles, are selected. The data analysed were recorded by the ATLAS experiment during 2015 using the 13 TeV centre-of-mass proton--proton collisions at the Large Hadron Collider, and correspond to an integrated luminosity of 3.2 fb$^{-1}$. The search selected events with various jet multiplicities from $\ge 7$ to $\ge 10$ jets, and with various $b$-jet multiplicity requirements to enhance sensitivity. No excess above Standard Model expectations is observed. The results are interpreted within two supersymmetry models, where gluino masses up to 1400 GeV are excluded at 95% confidence level, significantly extending previous limits.