Two-pion interferometry in central nucleus-nucleus collisions at the CERN SPS — Results from experiments NA35 and NA49

Relativistic heavy-ion collisions in the dynamical string-parton model

“…This was necessary because at low transverse momenta a cut was applied at 0.3 GeV. Also in comparing rapidity distributions for different systems one has to keep in mind that different forward energy triggers may affect the spectra differently [41]. In summary, we find satisfactory results except for the projectile hemisphere for the gold data, where the theory appears to underpredict the stopping of the incident proton.…”

“…The dashed curve is again the results of the DSP model for a nucleon-nucleon collision. In both the theory and the data, the multiplicity of negative hadrons increases with target mass and the maximum shifts to lower rapidities, indicating [41] π − production after multiple collisions. We also see that the high rapidity y ≥ 1.7 region for p +S collisions is very near the p +p result indicating that this region is determined by a single scattering.…”

“…The nucleus and the proton are then boosted towards each other with the collision Lorentz factor γ to reach the energy of the reaction, and the time evolution proceeds via the string equations of motion. We here apply the DSP model to minimum bias data [41] for p+S and p+Au collisions at 200 GeV per nucleon. The rapidity distributions of net nucleons for minimum bias p+S and p+Au [43] are shown in Figs.…”

“…On the other hand, looking at the target hemisphere, y < 0, the data and the theory are quite compatible. Some caution must be made in drawing conclusions that make use of the lowest (y ≤ −2.8) and highest (y ≥ 2.8) rapidity points These data [41] were extrapolated on the basis of a thermal fit. This was necessary because at low transverse momenta a cut was applied at 0.3 GeV.…”

Lambda production in central Pb $plus$ Pb collisions at CERN-SPS energies

“…For 158 A·GeV the rapidity distribution must be extrapolated, using realistic estimates of the tails of the dn dy distribution, e.g. those of the net-proton distribution at 158 A·GeV [9] or the Λ rapidity distribution in central S+S collisions [10]. In figure 7 (left), the total multiplicities as well as the AGS measurements [11] [12] are summarized.…”