Azimuthal distributions of final-state particles and fragments and transverse structure of emission source in high-energy nucleus--nucleus collisions

The azimuthal distributions of final-state particles and fragments produced in high-energy nucleus--nucleus collisions are described by a modified multisource ideal gas model which contains the expansions and movements of the emission sources. The transverse structures of the sources are given in the transverse plane by momentum components p_x and p_y, and described by parameters in the model. The results of the azimuthal distributions, calculated by the Monte Carlo method, are in good agreement with the experimental data in nucleus--nucleus collisions at high energies.