PHOTON PRODUCTION IN S+AU NUCLEAR COLLISIONS AT SPS ENERGIES

A modified hydrodynamical ''tube'' model is applied to study hard ther mal photon production from the quark-gluon plasma (QGP) and hot hadron ic matter in central S + Au nuclear collisions at SPS energies. Resona nce production and the jump of the sound velocity at the phase transit ion between hadronic phase and QGP is taken into account. Hard direct photon emission is also investigated with the consideration of nuclear shadowing effect on structure function of quarks and gluons. The pred icted photon yield does not contradict the experimental data obtained by the WA80 Collaboration.