A search for the production of direct photons in S+Au collisions at 200A GeV has been carried out in the CERN-WA80 experiment. For central collisions the measured photon excess at each p T , a v eraged over the range 0.5 GeV/c p T 2.5 GeV/c, corresponded to 5.0% of the total inclusive photon yield with a statistical error of stat =0.8% and a systematic error of syst =5.8%. Upper limits on the invariant yield for direct photon production at the 90% C.L. are presented. Possible implications for the dynamics of high-energy heavy-ion collisions are discussed.

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We have begun a program to measure dielectron production in /^-nucleus and nucleus-nucleus collisions at the LBL Bevalac. Results are presented for the reaction /? + Be at 4.9 GeV. For the first time, direct dilepton production is observed below 10 GeV incident energy. The cross sections are discussed and compared to previous data at higher energies. The observation of a structure at a mass of about 275 MeV suggests that pion annihilation may be the dominant production mechanism in this mass range.

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