pi(+) pi(+) pi(+) correlations from sulphur-lead collisions at 200 GeV/c pe
r nucleon are presented as measured by the focusing spectrometer of experim
ent NA44 at CERN. We have investigated the three-pion correlation function
at mid-rapidity and found that a genuine three-body correlation is suppress
ed. A possible interpretation of this result is that the emission of partic
les is partially coherent. (C) 1999 Elsevier Science B.V. All rights reserv
ed.