Hadron Production in Nuclear Collisions—a New Parton-Model Approach

We consider a quark-parton model in which wee partons of the projectile interact with wee partons of essentially independent nucleons in the nuclear target. The ratio of multiplicities in the central region is $\frac{{〈n〉}_{\mathrm{HA}}}{{〈n〉}_{\mathrm{HN}}}=\frac{1}{2}\overline{\nu }+\frac{\overline{\nu }}{(\overline{\nu }+1)}$, where $\overline{\nu }$ is the mean number of inelastic collisions of the projectile $H$, in agreement with experiment. We also predict nucleus-nucleus multiplicities, the multiplicity distribution, and the absence of shadowing in large-$q^2$ and large-$p_T$ reactions.