Spin contents of nucleons with SU(3) breaking

We apply a model for SU(3) breaking to the analysis of the spin contents of the nucleon from the the latest data on first moments of the spin dependent structure functions and include higher order QCD corrections. The results show that the value of the total quark spin contribution to the nucleon spin ΔΣ ≡ Δu + Δd + Δs remains about 0.3 and is very insensitive to SU(3) breaking, while the result for the strange quark contribution varies considerably with SU(3) breaking.