New results on the spin dependent structure function g1pfrom SMC

We present a preliminary measurement of the spin-dependent structure function g 1 p of the proton from deep inelastic scattering of 190 GeV polarized muons on polarized protons performed in 1996. The results are combined with our previous measurement of g 1 p . A perturbative QCD evolution in next-to-leading order is used to compute g 1 p at a constant Q 2 of 10 GeV 2 . Assuming a Regge type low x behaviour in the region (x we determine Γ 1 p =0.149±0.006±0.009±0.005 (preliminary). Using our recently published deuteron data we test the Bjorken sum rule. We note that the values of the first moments, both of the proton and deuteron, depend critically on the low x assumptions.