Abstract :
We check the u and d quark contributions to the spin content of the Λ by means of the q→Λ fragmentation and find that the u and d quarks of the Λ are likely positively polarized. The parton distributions in the Λ are given by a successful statistical model which can reproduce and correlate a vast body of polarized and unpolarized structure function and parton distribution data of the nucleon. With the Gribov–Lipatov relation between the quark distributions and fragmentation functions, the longitudinal spin transfer for the Λ production in the polarized charged lepton deep inelastic scattering (DIS) process and the Λ-polarization in the neutrino (antineutrino) DIS process are predicted. The available experimental data suggests that the u and d quark contributions to the spin of the Λ are positive. In addition, our results provide a collateral evidence for the SU(3) symmetry breaking in hyperon semileptonic decays of the octet baryons, which is very important for a deeper understanding of the proton ‘spin crisis’.
