Intermittency and correlations in hadronic Z0 decays
The OPAL Collaboration
G.Abbiendi2 - et al.
2 Dipartimento di Fisica dell' Università di Bologna and INFN,
I-40126 Bologna, Italy
Received: 8 February 1999 / Published online: 8 September 1999
A multidimensional study of local multiplicity fluctuationsand multiparticle correlationsof hadrons produced in Z0 decays is performed. The study is based on the data sample of more than events recorded with the OPAL detector at LEP. The fluctuationsand correlationsare analysed in terms of the normalized scaled factorial momentsand cumulantsup to the fifth order. The momentsare observed to have intermittency-like behaviour, which is found to be more pronounced with increasing dimension. The large data sample allows for the first time a study of the factorial cumulantsin e+e-annihilation. The analysis of the cumulantsshows the existence of genuine multiparticle correlationswith a strong intermittencyrise up to higher orders. These correlationsare found to be stronger in higher dimensions. The decomposition of the factorial momentsinto lower-order correlationsshows that the dynamical fluctuationshave important contributions from genuinemany-particle correlations. The Monte Carlomodels JETSET7.4 and HERWIG5.9 are found to reproduce the trend of the measured moments and cumulants but they underestimate the magnitudes. The results are found to be consistent with QCD jet formation dynamics, although additional contributions from other mechanisms cannot be excluded.