Three-pion correlations in relativistic heavy ion collisions

We report the results of three-pion interferometry for two streamer chamber data samples: 1.8 GeV/nucleon Ar on Pb and 1.5 GeV/nucleon Ar on KCl. The fitted pion source parameters are consistent with previously reported results of two-pion interferometry. The effect of three-pion interference on the pion source parameters obtained from two-pion interferometry is also studied. The distortion becomes a serious problem in the data analysis only when the pion source has a small radius and low temperature.