Search for Anomalous Production of Multilepton Events in p-pbar Collisions at sqrt(s) = 1.96 TeV

TL;DR

This paper searches for unusual multilepton events in proton-antiproton collisions at 1.96 TeV, finding results consistent with standard model predictions and setting mass limits on supersymmetric particles within a specific model framework.

Contribution

It provides the first search for multilepton anomalies at this energy and interprets results as new mass limits on neutralino and chargino particles in R-parity violating supergravity models.

Findings

Six events observed in three-lepton sample, consistent with background.

Zero events observed in four-or-more-lepton sample.

Set mass limits: neutralino > 110 GeV/c^2, chargino > 203 GeV/c^2 at 95% CL.

Abstract

We report a search for the anomalous production of events with multiple charged leptons in p-pbar collisions at sqrt{s} = 1.96 TeV using a data sample corresponding to an integrated luminosity of 346 pb^{-1} collected by the CDF II detector at the Fermilab Tevatron. The search is divided into three-lepton and four-or-more-lepton data samples. We observe six events in the three-lepton sample and zero events in the >=4-lepton sample. Both numbers of events are consistent with standard model background expectations. Within the framework of an R-parity violating supergravity model, the results are interpreted as mass limits on the lightest neutralino and chargino particles. For one particular choice of model parameters, the limits are M_neutralino > 110 GeV/c^{2} and M_chargino > 203 GeV/c^{2} at 95% confidence level; the variation of these mass limits with model parameters is presented.