Neutral-strange-particle production inpNe20andpNinteractions at 300 GeV

Data on multiplicity, correlations, and inclusive spectra of $K_S^0$ mesons and ${\Lambda }^0\left({\overline{\Lambda }}^0\right)$ hyperons produced with $x_F\le 0$ in inelastic $p{}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ and $\mathrm{pN}$ interactions at 300 GeV are presented and compared. The inclusive cross sections for $p{}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ ($\mathrm{pN}$) with $x_F\le 0$ are 61.1±2.8 mb (3.34±0.64 mb) for $K_S^0$, 40.8±2.5 mb (1.89±0.29 mb) for ${\Lambda }^0$, and 3.9±0.5 mb (0.31±0.08 mb) for ${\overline{\Lambda }}^0$. The multiplicity ratio for $p{}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ and $\mathrm{pN}$ interactions is 1.58±0.16 for $K_S^0$, 1.95±0.23 for ${\Lambda }^0$, and 1.12±0.43 for ${\overline{\Lambda }}^0$. We have observed the ${\Sigma }^0\mathrm{}\left(1193\right)\mathrm{}$ hyperon and measured the average multiplicity ($n_{{\Sigma }^0}=0.049\mathrm{}\pm 0.027$) for $x_F\le 0$. We have also observed the strange resonances $K^{*}\mathrm{}\left(892\right)\mathrm{}$, $K^{*}\mathrm{}\left(1415\right)\mathrm{}$, and ${\Sigma }^{*}\mathrm{}\left(1385\right)\mathrm{}$ with $x_F\le 0$ and measured the fraction of $V^0$ coming from each resonance. ${\Lambda }^0$ polarization for $x_F\le 0$ is measured and shows a decrease as $p_{\perp }$ increases [$p_{\Lambda }\left(p{}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}\right)\approx -0.25\mathrm{}$ at $p_{\perp }=1.5\mathrm{}$ GeV/c], in agreement with other experiments which measure polarization in the region $x_F\gg 0$. Since (43±7)% of the ${\Lambda }^0$ are produced in ${\Sigma }^0\to {\Lambda }^0\gamma$ decays, the ${\Lambda }^0$ polarization is significantly greater than the measured values. Experimental results are compared to predictions of the Lund model and the dual parton model of soft hadron-nucleus and hadron-nucleon interactions.