Hadron production in nuclear collisions from the NA49 experiment at 158GeV/c center dot A

With its large acceptance and particle identification coverage the NA49 exp eriment (Fig. 1) can study hadron production in a wide range of high energy reactions [1]. Originally aimed at examining central Pb+Pb collisions for signatures of quark-gluon plasma formation, the scope of the experiment has been enhanced with the systematic study of impact parameter and projectile size dependence, as well as the inclusion. of the more elementary p+p and p+A interactions. The question is: are predicted signals of the quarkgluon plasma observed and are there discontinuities which would support the conce pt of hadronic phase transition?.