QCD analysis of the Bjorken sum rule revisited

We present extended analysis of the polarized Bjorken sum rule using the four-loop expression for the coefficient function CBj(αs) available now and the recent low Q2-data from the Jefferson Lab and COMPASS experiments. We demonstrate that the perturbative series for the function CBj gives a hint to its asymptotic nature manifesting itself in the region Q2 ≲ 1 GeV2. It is confirmed by the considered integral model for the perturbative QCD correction. We analyze values of higher-twist terms extracted from the mentioned data and discuss the interplay between higher orders perturbative and higher-twist contributions. We extend our consideration to the Gross-Llewellyn Smith sum rule and investigate the relation between higher twist coefficients in these two sum rules.