TOP SEARCH AT FERMILAB - MULTIJET SIGNALS AND BACKGROUNDS

We investigate the possibilities of finding the top quark at the FNAL Tevatron pp collider (√s = 1.8 TeV). For a top-quark mass greater than O(MW) top quark will be predominantly produced through direct QCD tt production. The decay channel into a lepton, neutrino and a number of jets together with the dominant background signal is examined. We first study the standard way of finding the top-quark mass using invariant mass distributions. We then introduce and study the quantity R 3 2(mtop), defined as the ratio of the number of "3 jet + lepton" events to the number of "2 jet + lepton" events. Through the strong dependence on the top-quark mass of this simple ratio it should be possible to detect the presence of a top quark for a large range of possible top-quark mass values. © 1990.