Abstract
SPb and SS interactions at 200 A GeV/c, as measured by the NA36 experiment at CERN, have been classified according to the number of participant protons of the projectile, by means of a precise identification of the charge of the projectile fragment produced. Rapidity and transverse momentum spectra of π- associated with the production of Z = 10 to Z = 15 projectile fragments are presented and compared to three models with different mechanisms of final particle production.