Tests of QCD using differences between gluon and quark jets

Abstract

I present recent results from LEP which utilize differences between gluon and quark jets to make quantitative tests of QCD. The principal topic is a determination of the ratio of QCD color factors, C$_{\mathrm{A}}$/C$_{\mathrm{F}}$, using either the multiplicity or fragmentation functions of the jets. In addition, I discuss a recent measurement of the rate of $\eta$ mesons in gluon jets compared to quark jets.Comment: Talk given at the International Europhysics Conference, High Energy Physics 99, Tampere, Finland, 15-21 July 199