Gluon splitting into heavy quarks in $e^+ e^-$ annihilations

Abstract

Measurements of the multiplicity of heavy quark pairs from gluon splitting in e + e annnihilations at LEP are presented. A counting technique, based on the b-tagging of jets in 4-jet topologies,has been used by DELPHI to measure $\overline{n}_{g \to b\overline{b}}$. The mean multiplicity of gluons splitting into $b\overline{b}$ was measured to be $\overline{n}_{g \to b\overline{b}}$ = (0.22 +- 0.13) x $10^{-2}$. The multiplicity of gluons splitting into $c\overline{c}c$\overline{n}_{g \to c\overline{c}}$has been measured by OPAL in two separate analyses. In the first, the production of$D^{*+-}$mesons at very low$x_D*$is studied and indications for$c\overline c production from gluon c\overline{c}} measurements are consistent with theoretical expectations