The Proton Spin Puzzle and $\mathrm{\Lambda }$ Polarization in Deep--Inelastic Scattering

We point out that measurements of longitudinal $\mathrm{\Lambda }$ polarization in the target fragmentation region of deep–inelastic $\nu N$ and $\mu N$ or $e , N$ scattering may test dynamical mechanisms invoked to explain the proton spin puzzle. A previously-proposed model for polarized $\bar{s}s$ pairs in the proton wave function reproduces successfully the negative $\mathrm{\Lambda }$ polarization found in the WA59 $\bar{\nu }N$ experiment, and makes predictions that could be tested in future $\mu N$ and $eN$ experiments.