Atomic-Number Dependence of Large-Transverse-Momentum Hadron Production by Protons

We have measured at Fermilab the production of hadrons at ∼90° in the c.m. system as a function of incident proton energy, atomic number $A$ of the production target, and the transverse momentum $p_{\perp }$ of the produced hadron. The $A$ dependence of the production cross section of the hadrons can be described by a function $A^{\propto \left(p_{\perp }\right)}$, where the power $\alpha$ rises with $p_{\perp }$. At $p_{\perp } \sim 5$ GeV/c, $\alpha$ is ∼1.1 for ${\pi }^{\pm }$ and $K^{+}$, and ∼1.3 for $p$, $\overline{p}$, and $K^{-}$. The energy dependence of the power is also measured.