ΛHyperons Produced in Central Nucleus-Nucleus Interactions at 4.5 GeV/cMomentum per Incident Nucleon

Transverse momenta and rapidities of $\Lambda \text{'}\mathrm{s}$ produced in central nucleus-nucleus collisions at 4.5 GeV/c·u (C-C,...,O-Pb) were studied and compared with those from inelastic He-Li interactions at the same incident momentum. Polarization of the $\Lambda$ hyperons was found to be consistent with zero ($\alpha P=-0.06=0.11\mathrm{}$ for $\Lambda \text{'}\mathrm{s}$ from central collisions). An upper limit of the $\frac{\overline{\Lambda }}{\Lambda }$ production ratio was estimated to be less than 4.5×${10}^{-3\mathrm{}}$. The experiment was performed in a triggered streamer chamber.