Improved description of Bose-Einstein Correlation function

The L3 data on Bose-Einstein correlations of equally charged pion pairs produced in hadronic Z decays are analyzed in terms of various parametrizations. Preliminary results are presented here.Comment: Presented at the RHIC School 04, 4th Budapest Winter School on Heavy Ion Physics, Budapest, Hungary, December 1-3, 2004. To be published in Acta Physica Hungarica Heavy Ion Physic