One and two-dimensional analysis of 3π correlations measured in Pb+Pb interactions

Abstract π − π − π − correlations from Pb+Pb collisions at 158 GeV/ c per nucleon are presented as measured by the focusing spectrometer of the NA44 experiment at CERN. The three-body effect is found to be stronger for Pb+Pb than for S+Pb. The two-dimensional three-particle correlation function is also measured and the longitudinal extension of the source is larger than the transverse extension.