The study of the directional dependence of two-particle correlations in the hadronic decays of the Z(0) boson is performed using the data collected by the DELPHI experiment in the 1992-1995 running periods. The comparison between the transverse, R-perpendicular to, and longitudinal, R-parallel to, correlation radii confirms the string model prediction that the transverse correlation length is smaller than the longitudinal one, with the measured values of R-perpendicular to = 0.53 +/- 0.08 fm and R-parallel to = 0.85 +/- 0.08 fm, for selected Z(0) --> q (q) over bar events. (C) 2000 Published by Elsevier Science B.V. All rights reserved.
