The strange quark spin of the proton in semi-inclusive $\Lambda$ leptoproduction

Considering the possible interpretation of the Ellis-Jaffe sum rule violation that the strange quark in the polarized proton is remarkably polarized in the opposite direction of the proton spin, we investigate its implication in the semi-inclusive $\Lambda$ production in deep inelastic process with the electron beam unpolarized and proton target polarized longitudinally. As a result, we find that the measurement of the $\Lambda$ polarization in the process considered can provide clean information about the strange quark spin distribution in the proton.