Angular Distributions of Secondary Particles Produced in High-Energy Nuclear Collisions and the Two-Center Model of Multiple Meson Production

The angular distributions of shower particles from 54 nuclear interactions of protons and neutrons with energies > ${10}^{12}$ ev in a stack of nuclear emulsions are analyzed. The method consists essentially in normalizing the angular distributions of all events in the $x=logtan\theta$ scale to the same dispersion $\sigma$. One finds a very significant deviation from the normal distribution predicted by hydrodynamical models. The deviation goes in the direction indicated by the two-center model (two maxima in the plot over the $x$ coordinate). The correlation between the separation of the two emitting centers and $\sigma$ is also in qualitative agreement with the model. The angular distribution in the rest system of the emitting centers is found to be roughly isotropic. The two-center model also offers an explanation for certain characteristic features observed for the angular distribution of events with a small number of shower particles ($n_s\leqq 5$). On the basis of this model a coefficient of inelasticity of ≈0.2 is obtained for these events.