Comments on the jet activity in Isajet top events

Abstract

For the top analysis at the Hadron Collider various Monte Carlo generators are in use, like Isajet, Herwig or Pythia. These so called «shower» Monte Carlos create gluon radiation, in addition to the hard scattering process and the electroweak to decay. They do this using «reasonable» models, but not based on first principles. This gluon radiation can very much affect the top analysis, but it is not clear whether it is modelled well.