Three pion interferometry in the NA44 experiment

This thesis presents a three-particle correlation analysis with pions originating from Sulphur-Lead and Lead-Lead collisions at 200 and 158 GeV/c per nucleon respectively, taken by the CERN heavy-ion experiment NA44. The genuine three-body correlation is suppressed in both colliding systems which indicates that the particle production source is partly coherent. The two-dimensional three-particle correlation function for Lead-Lead is asymmetric in longitudinal and transverse direction. Correction methods for three-, four- and five-body Coulomb are described.