Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb^-1 of sqrt(s) = 7 TeV proton-proton collisions

TL;DR

This paper reports a search for new particles with high jet multiplicities and missing transverse momentum in proton-proton collisions at 7 TeV, setting new limits on gluino masses within supersymmetric models.

Contribution

First search using large jet multiplicities and missing transverse momentum at 7 TeV with ATLAS, extending gluino mass exclusion limits in supersymmetric models.

Findings

No evidence for new physics beyond the Standard Model.

Excluded gluino masses below 840 GeV for large scalar masses.

Excluded gluino masses below 870 GeV for certain neutralino masses.

Abstract

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb^-1 of pp collision data at sqrt(s) = 7 TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from >=6 to >=9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m_0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV.