Hyperfine Splitting in Light-Flavour Hadron Production at LEP

The production rates of light-flavour hadrons at LEP~1 are set by their masses, spins, strangeness suppression, and strongly influenced by the spin-spin interactions of their quarks. Similarities in production of pseudoscalar mesons and octet baryons, vector mesons and decuplet baryons are observed and explained by the relative spin configurations of their quarks. Similarity in production of tensor mesons and $\Lambda(1520)$ is also seen. The vector-to-pseudoscalar meson and decuplet-to-octet baryon suppressions are the same and explained by the hyperfine mass splitting. The strangeness suppression factor, $\lambda = 0.295 \pm 0.006$, is the same for mesons and baryons. It is related to the difference in the constituent quark masses, $\lambda = e^{-(m_s-\hat{m})/T}$, where $\hat{m} = m_u = m_d$, at the temperature, $T = 142.4 \pm 1.8$~MeV/$c^2$. No evidence for additional suppression of strange baryons is observed. The LEP~1 data are compared with hadronic reactions and heavy nuclear collisions.