The comparison of characteristics of pi^{-} mesons produced in central Mg-Mg interactions with the quark gluon string model predictions

A detailed study of pion production in central Mg-Mg collisions at a momentum of 4.3 GeV/c per incident nucleon was carried out with use of the setup GIBS. The average kinematical characteristics of pions (multiplicity n_, momentum P, transverse momentum P_{T}, emission angle Q, rapidity Y) and corresponding distributions have been obtained. The experimental results have been compared with the predictions of the Quark Gluon String Model (QGSM) and satisfactory agreement between the experimental data and the model has been found. The QGSM reproduces also the dependence of average P_{T} on n_{-}. The temperatures of pi^{-} mesons have been estimated in the rapidity interval of 0.5<=Y<=2.1. A satisfactory fit for pi^{-} mesons has been achieved by using a form involving two temperatures T_{1} and T_{2}. It was found that the QGSM underestimates T_{2} by (10-15)%. The data have been analyzed using the transverse momentum technique. The observed dependence of the on Y shows the S-shape behaviour. The slope at midrapidity F had been determined. The QGSM reproduces the distribution satisfactorily, but underestimates the parameter F.Comment: 21 pages with 9 postscript figure

The analysis of pi^{-} mesons produced in nucleus-nucleus collisions at a momentum of 4.5 GeV/c/nucleon in light front variables

The light front analysis of pi^{-} mesons in He(Li,C), C-Ne, C-Cu and O-Pb collisions is carried out. The phase space of secondary pions is divided into two parts in one of which the thermal equilibrium assumption seems to be in a good agreement with the data. Corresponding temperatures T are extracted and their dependence on (A_{P}*A_{T})^{1/2} is studied. The results are compared with the predictions of the Quark-Gluon String Model (QGSM). The QGSM satisfactorily reproduces the experimental data for light and intermediate-mass nuclei.Comment: 14 pages with 9 postscript figure

Light-Front Analysis of pi^{-} Mesons Produced in Mg - Mg Collisions at 4.3 a Gev/c

Light-front analysis of pi^{-} mesons in Mg-Mg collisions is carried out. The phase space of secondary pions is naturally divided into two parts in one of which the thermal equilibration assumption seems to be in a good agreement with data. Corresponding temperatures are extracted and compared to the results of other experiments. The experimental results have been compared with the predictions of the Quark Gluon String Model (QGSM) and satisfactory agreement between the experimental data and the model has been found.Comment: 14 pages with 7 postscript figures. accepted for publication in Nucl. Phys.