Helicity and transversity distributions of the nucleon and Λ hyperon from Λ fragmentation -: art. no. 014017

It is shown that Lambda -hyperon fragmentation in charged lepton deep inelastic scattering on a polarized nucleon target can provide sensitive information concerning the quark helicity and transversity distributions for both the nucleon and Lambda hyperon at large x. Numerical predictions are given for the spin transfers of the produced Lambda, when the target nucleon is polarized either longitudinally or transversely, and with the nucleon and Lambda quark distributions evaluated both in an SU(6) quark-spectator-diquark model and in a perturbative QCD based model. It is also shown that the predicted spin transfers have different behaviors for proton and neutron targets, and this can provide sensitive tests of different predictions for the quark helicity and transversity distributions of the d valence quark of the proton at large x.