NATURE OF THE PHOTON-CORRELATION FUNCTION FOR QUARK-GLUON PLASMA

The correlation function for intensity interferometry of high energy p hotons emitted from an expanding quark-gluon plasma is examined. It is reiterated that the correlation function for identical bosons emitted from two point sources is given by 1 + cos(DELTAk . DELTAx) and will oscillate between 0 and 2, depending on the values of the difference i n the 4-momenta of the two bosons (DELTAk) and the difference in their 4-positions (DELTAx). Integration over smooth, realistic sources, rel evant for very high energy nucleus-nucleus collisions, gives a correla tion function which essentially decreases monotonically from 2 to 1 as the momentum difference becomes large. The oscillatory behavior seen in a recent work for certain momentum configurations is caused by an a pproximation which amounts to including only those sources for which t he space-time rapidities are identical to the photon rapidities.