A search for supersymmetry in the trilepton final state is performed using the full dataset of
the DØ experiment. The analyzed data amounts to an integrated luminosity of ∫ℒ = 9.7 fb⁻¹ of pp̅ collisions, produced
at √s = 1.96 TeV at the Fermilab Tevatron collider. The studied process is the coproduction
of charginos and neutralinos, decaying into a final state of three leptons and missing
transverse energy. To increase efficiency, only two identified leptons (e, µ) and one additional
isolated track are required per event. The QCD multijet background is estimated from data,
while other backgrounds are modeled via Monte Carlo. After a series of background-reduction
cuts, a multivariate analysis is performed using boosted decision trees (BDT). In the distribution
of the BDT output, no excess of data over background is seen. Limits on the cross section are set
for the mSUGRA (CMSSM) model, as well as for a scenario with non-universal gaugino masses.
