CENTRALITY DEPENDENCE OF PION AND PROTON SPECTRA IN C+C AND C+TA INTERACTIONS AT 4.2 GEV C PER NUCLEON/

Target and centrality dependence of pion and proton distributions is s tudied in C+C and C+Ta collisions at 4.2 GeV/c per nucleon using the 2 -m propane bubble chamber. The experimental data are compared with the predictions of the Monte Carlo quark-gluon string model (QGSM). The p ion and proton transverse momentum spectra at midrapidity are well des cribed by the two-component thermal model. The shape of the proton rap idity distribution strongly depends on the collision centrality and re flects the stopping power of colliding nuclei. The pion rapidity distr ibution is Gaussian in shape regardless of the target mass number and collision centrality. The QGSM completely reproduces main features of pion and proton rapidity spectra as well as pion transverse momentum s pectra. The model does not fully reproduce the features of the proton transverse momentum spectra.