Systematic studies of hadron production in heavy-ion collisions at SPS energies

Hadron production in A+A interactions is studied by the CERN experiment NA49 in dependence on energy and system size: p+p, central C+C, Si+Si and Pb+Pb collisions were measured at 158 AGeV, Pb+Pb also at 40 and 80 AGeV. Spectra and particle yields are interpreted on the basis of thermal models assuming an equilibrated hadron gas. Special emphasis is put on a systematic investigation of strangeness production. It is found to increase with system size. The energy dependence indicates a maximum for central Pb+Pb collisions at about 40 AGeV. (13 refs).