A lattice study of the spin structure of the Λ hyperon

The internal spin structure of the Λ is of special importance for the understanding of the spin structure of hadrons in general. The comparison between the nucleon and Λ allows for a test of the relevant flavour-symmetry breaking effects. Using nonperturbatively O(a) improved Wilson fermions in the quenched approximation we have calculated the first moments of the unpolarised, longitudinally polarised and transversity quark distribution functions in the Λ. The results indicate that flavour symmetry breaking has little effect on the internal spin structure, in accordance with model based expectations.