Multiplicity dependence of Bose-Einstein correlations in hadronic Z0 decays Academic Article uri icon


  • Bose-Einstein correlations between like charged track pairs have been studied using a sample of approximately 3.6 million multihadronic Z0 decays collected with the OPAL detector at LEP. The radius of the emitting sourceR and the chaoticity parameterλ were studied using two parametrisations, the Goldhaber (G) parametrisation and the one-dimensional Kopylov-Podgoretskii (KP) parametrisation. The radiiR G andR KP are found to increase linearly with the average observed charged multiplicityn ch , with changes with respect to a unit increase inn ch of $$\begin{gathered} \frac{1}{{\langle R_G \rangle }}\frac{{\Delta R_G }}{{\Delta n_{ch} }} = (3.6 \pm 0.6) \cdot 10^{ - 3} and \hfill \\ \frac{1}{{\langle R_{KP} \rangle }}\frac{{\Delta R_{KP} }}{{\Delta n_{ch} }} = (3.4 \pm 1.0) \cdot 10^{ - 3} . \hfill \\ \end{gathered} $$ where the 〈R〉 are the radius values measured in the inclusive event sample. The chaoticity parametersλ G andλ KP decrease with increasing charged multiplicity. It is shown that the increase ofR with multiplicity may be connected with differences between two- and three-jet events.


publication date

  • January 1, 1996