Strangeness production in proton and heavy ion collisions at 200A GeV

Strangeness production at the CERN Super Proton Synchrotron energies is studied within the quark-gluon string model. The observed shape of rapidity and transverse mass distributions are reproduced fairly well for both peripheral and central heavy ion collisions. However, for central collisions the model underpredicts strange particle abundances by a factor of about 2:2:4 for ${\mathit{K}}_{\mathit{S}}^0$, Λ, and Λ¯, respectively. This discrepancy can be considered as a possible manifestation of collective string-string interactions similar to the formation of a color rope. Model predictions for coming experiments with the Pb beam at CERN are given.