Trilepton signal of minimal supergravity at the Tevatron including τ-lepton contributions

The trilepton signal with missing transverse energy (3ℓ+ E/T, with ℓ=e or μ) from chargino-neutralino (χ±1χ02) associated production and decays is studied for the upgraded Fermilab Tevatron Collider with 2 TeV center of mass energy and integrated luminosity of 2 fb−1 (MI) to 20 fb−1 (TeV33). In some regions of parameter space in the minimal supergravity model, χ±1 and χ02 decay dominantly into final states with τ leptons via real or virtual τ̃1 sleptons. The contributions from τ−leptonic decays increase the trilepton signal from χ±1χ02 by at least a factor of two when soft but realistic cuts on lepton transverse momenta are used. With the Main Injector, a trilepton signal can be detected at tanβ≡v2/v1∼3 for universal masses m1/2,m0≲ 200 GeV.