Search for electroweak production of supersymmetric particles in final states with two or three leptons at [Formula omitted] with the ATLAS detector

• Published in: The European physical journal. C, Particles and fields Vol. 78; no. 12; pp. 1 - 36
• Main Authors: Aaboud, M, Aad, G, Abbott, B, Abdinov, O, Abeloos, B, Abidi, S. H, AbouZeid, O. S
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-12-2018; Springer Nature B.V
• Subjects: Bosons; Confidence intervals; Decay; Fermions; Large Hadron Collider; Leptons; Muons; Pair production; Particle collisions; Particle physics; Quarks; Standard model (particle physics); Supersymmetry
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-018-6423-7

A search for the electroweak production of charginos, neutralinos and sleptons decaying into final states involving two or three electrons or muons is presented. The analysis is based on 36.1 fb [Formula omitted] of [Formula omitted] TeV proton-proton collisions recorded by the ATLAS detector at the Large Hadron Collider. Several scenarios based on simplified models are considered. These include the associated production of the next-to-lightest neutralino and the lightest chargino, followed by their decays into final states with leptons and the lightest neutralino via either sleptons or Standard Model gauge bosons; direct production of chargino pairs, which in turn decay into leptons and the lightest neutralino via intermediate sleptons; and slepton pair production, where each slepton decays directly into the lightest neutralino and a lepton. No significant deviations from the Standard Model expectation are observed and stringent limits at 95% confidence level are placed on the masses of relevant supersymmetric particles in each of these scenarios. For a massless lightest neutralino, masses up to 580 GeV are excluded for the associated production of the next-to-lightest neutralino and the lightest chargino, assuming gauge-boson mediated decays, whereas for slepton-pair production masses up to 500 GeV are excluded assuming three generations of mass-degenerate sleptons.