Search for supersymmetry in events with three leptons and missing transverse momentum in sqrt(s) = 7 TeV pp collisions with the ATLAS detector

TL;DR

This paper reports a search for supersymmetric particles in events with three leptons and missing transverse momentum using 7 TeV proton-proton collision data from the ATLAS detector, setting new exclusion limits.

Contribution

It presents the first search for charginos and neutralinos in three-lepton final states at 7 TeV, establishing new mass exclusion limits in simplified supersymmetry models.

Findings

No significant excess over standard model expectations.

Excluded charginos and neutralinos up to 300 GeV in simplified models.

Set 95% confidence level upper limits on production cross sections.

Abstract

A search for the weak production of charginos and neutralinos into final states with three electrons or muons and missing transverse momentum is presented. The analysis uses 2.06 fb^-1 of sqrt(s) = 7 TeV proton-proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with standard model expectations in two signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric and simplified models. For the simplified models, degenerate lightest chargino and next-to-lightest neutralino masses up to 300 GeV are excluded for mass differences from the lightest neutralino up to 300 GeV.