Neutral-strange-particle production by 300-GeV protons

A neutral beam designed to transmit a high flux of Λ⁰ hyperons with momenta above 50 GeV/c has been built and operated at Fermilab. Inclusive production cross sections per target nucleus have been measured for p+A→Λ⁰+X, p+A→KS⁰+X, and p+A→Λ⁰+X with 300-GeV protons incident on solid targets $A=berylium,{{0ex}{0ex}}copper,{{0ex}{0ex}}and{{0ex}{0ex}}lead$. The region of phase space covered is predominantly projectile fragmentation: $0.2<~x<~1$, $0<~{p}_{{⊥}}<~2$ GeV/c. The $A$ dependence of the inclusive cross sections is analyzed. The cross sections are compared to other work in $pp$ collisions by extrapolating the $A$ dependence to $A=1$. The results of measurements of ${{Λ}}⁰$ and ${{{Λ}}}⁰$ polarization from the beryllium target are presented.