Test of QCD Analytic Predictions for Gluon and Quark Jet Differences

Abstract

Differences between the properties of gluon and quark jets have been convincingly established by experiments at LEP. Quantitative tests of QCD analytic predictions for these differences have not been possible, however, because of differences between the theoretical and experimental definitions of the jets and event samples. Here, a new method to compare gluon and quark jet properties is described, which uses an inclusive definition of the jets in analogy to theoretical calculations. Using this new method, a value 1.552+-0.041(stat.)+-0.061(syst.) is found for the ratio of the mean charged particle multiplicity in gluon jets to that in quark jets, in agreement with a recent analytic calculation which incorporates energy conservation.