This thesis presents a search for R-parity violating supersymmetry at sqrt(s)=13 TeV, using approximately 13.3 fb-1 of data collected by ATLAS in 2015 and the first half of 2016. Events are required to contain at least four leptons (electrons or muons only) that are not the product of a Z boson decay, and this requirement results in a low Standard Model background and a high sensitivity to various physics models beyond the Standard Model. No significant deviations from the Standard Model are observed in data, and results are used to set upper limits on the event yields from processes beyond the Standard Model. In a simplified model of chargino production with indirect R-parity violating decays, limits are extended by approximately 400 GeV relative to the Run 1 search, excluding chargino masses below 1.1 TeV.

Two searches for supersymmetry in multilepton final states are presented using pp collisions at sqrt(s) = 8 TeV in the ATLAS detector. First, a search for electroweak production of charginos and neutralinos in the three-lepton plus missing transverse momentum channel is detailed with an emphasis on the fake-lepton background estimation technique. No significant excess above the Standard Model prediction is observed in the signal regions. Exclusion limits are thus placed on simplified models of chargino1-neutralino2 production and decays via intermediate sleptons, SM gauge bosons, and Higgs bosons. The results are also interpreted in terms of the phenomenological MSSM. Next, a search for R-parity violating and R-parity conserving supersymmetric scenarios in the four-lepton channel is presented. No significant excess is observed, so exclusion limits are placed R-parity violating simplified models in which the lightest supersymmetric particle is the lightest neutralino, which promptly decays to leptons. Exclusion limits are also placed on R-parity conserving simplified models of neutralino2-neutralino3 production.

Searches for R-parity violating supersymmetry with the D0 detector at the Fermilab Tevatron p{bar p}-collider are presented. In the case of non-zero LL{bar E} couplings {lambda}{sub ijk} {approx}> 0.01, multi-lepton final states, and for a small coupling {lambda}{sub 122} “0.01 di-muon final states are studied. The case of non-zero LQ{bar D} coupling {lambda}{prime}{sub 211} leads to final states with two muons and jets. A total integrated luminosity of 0.38 fb{sup -1} collected between April 2002 and August 2004 is utilized. The observed numbers of events are in agreement with the Standard Model expectation, and limits on R{sub p} supersymmetry are derived, extending significantly previous bounds.

Results are presented from searches for R-parity-violating supersymmetry in events produced in pp collisions at sqrt(s)=8 TeV at the LHC. Final states with 0, 1, 2, or multiple leptons are considered independently. The analysis is performed on data collected by the CMS experiment corresponding to an integrated luminosity of 19.5 inverse femtobarns. No excesses of events above the standard model expectations are observed, and 95% confidence level limits are set on supersymmetric particle masses and production cross sections. The results are interpreted in models featuring R-parity-violating decays of the lightest supersymmetric particle, which in the studied scenarios can be either the gluino, a bottom squark, or a neutralino. In a gluino pair production model with baryon number violation, gluinos with a mass less than 0.98 and 1.03 TeV are excluded, by analyses in a fully hadronic and one-lepton final state, respectively. An analysis in a dilepton final state is used to exclude bottom squarks with masses less than 307 GeV in a model considering bottom squark pair production. Multilepton final states are considered in the context of either strong or electroweak production of superpartners, and are used to set limits on the masses of the lightest supersymmetric particles. These limits range from 300 to 900 GeV in models with leptonic and up to approximately 700 GeV in models with semileptonic R-parity-violating couplings.