Search for top squarks in R-parity-violating supersymmetry using three or more leptons and b-tagged jets

Area of Science:

• High Energy Physics
• Particle Physics
• Supersymmetry

Background:

• The Standard Model (SM) of particle physics describes fundamental particles and forces.
• Supersymmetry (SUSY) is a theoretical extension to the SM predicting partner particles for known particles.
• R-parity violation in SUSY models allows for new decay channels and signatures.

Purpose of the Study:

• To search for anomalous production of events with multiple leptons and bottom jets in proton-proton collisions.
• To test predictions of supersymmetric models with R-parity-violating decays.
• To constrain the masses of top squarks and the lightest supersymmetric particle.

Main Methods:

• Analysis of proton-proton collision data collected by the CMS experiment at the Large Hadron Collider (LHC).
• Data corresponds to an integrated luminosity of 19.5 fb⁻¹ at a center-of-mass energy of 8 TeV.
• Search focused on events with three or more isolated leptons and bottom-quark jets.

Main Results:

• No significant excess of events beyond Standard Model expectations was observed.
• The results are interpreted within specific R-parity-violating supersymmetric models.
• Exclusion limits are placed on the masses of top squarks and the lightest supersymmetric particle.

Conclusions:

• The search did not find evidence for anomalous new physics phenomena.
• Light top-squark pair production with R-parity-violating decays is constrained.
• Top squarks are excluded below 1020 GeV and 820 GeV for a 200 GeV lightest supersymmetric particle in specific models.