Search for the electroweak production of supersymmetric particles in $\sqrt{s}$=8 TeV $pp$ collisions with the ATLAS detector

TL;DR

This paper reports on ATLAS searches for electroweak supersymmetric particles in 8 TeV proton-proton collisions, employing new analysis techniques to improve sensitivity, but finds no evidence of such particles beyond Standard Model predictions.

Contribution

It introduces new search strategies including vector-boson fusion and multivariate analysis to extend the sensitivity to supersymmetric particles with small mass differences.

Findings

No significant excess observed beyond Standard Model expectations.

Exclusion limits set at 95% confidence level for various supersymmetric models.

Combined analysis improves constraints on electroweak supersymmetry.

Abstract

The ATLAS experiment has performed extensive searches for the electroweak production of charginos, neutralinos and staus. This article summarizes and extends the search for electroweak supersymmetry with new analyses targeting scenarios not covered by previously published searches. New searches use vector-boson fusion production, initial-state radiation jets, and low-momentum lepton final states, as well as multivariate analysis techniques to improve the sensitivity to scenarios with small mass splittings and low-production cross-sections. Results are based on 20 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}$=8 TeV recorded with the ATLAS experiment at the Large Hadron Collider. No significant excess beyond Standard Model expectations is observed. The new and existing searches are combined and interpreted in terms of 95% confidence-level exclusion limits in simplified models, where a single production process and decay mode is assumed, as well as within phenomenological supersymmetric models.