New Signals for Gluinos and Squarks of Supergravity at the Tevatron Collider

Abstract

Within the supergravity framework, sleptons are expected to be considerably lighter than squarks if gluinos and squarks are approximately degenerate. This can lead to a significant enhancement in leptonic branching ratio for neutralinos, and sometimes, charginos. Using ISAJET 7.0/ISASUSY 1.0, we evaluate the multilepton signals from cascade decays of gluinos and squarks produced at the Fermilab Tevatron $p\bar p$ collider assuming squark and slepton masses are related as in supergravity models. We find observable cross sections for spectacular event topologies: $m$-lepton + $n$-jet + $\eslt$ events ($m \leq 4$, $n \geq 2$) and same-sign dilepton + $\eslt$ events and show that the SM backgrounds to the isolated trilepton, four lepton and same-sign dilepton signals are very small. These signals can extend the mass reach of the Tevatron experiments to $m_{\tg}\sim 300$~GeV if $m_{\tg}\sim m_{\tq}$ and ${\cal O}(1000)$ pb$^{-1}$ of data are collected.