Hadron polarization in e⁺e^- annihilation

Abstract

We show that while the polarization of the charmed quark produced in e⁺e^- annihilation is of the order of 3% at √s=5 GeV, it gets washed out in subsequent decays. This should therefore cause the polarization of Λ⁰ produced in e⁺e^-→Λ⁰X to show a sharp fall as the energy crosses the charm threshold. We discuss ways of measuring charmed-quark polarization in the decays of charmed hadrons.