Bjorken sum rule with analytic QCD coupling

We present details of study of the polarized Bjorken sum rule Gamma(p-n)(1)(Q(2)) carried out recently in [1]. Four QCD coupling versions are considered: perturbative QCD (pQCD) in the (MS) over bar scheme, Analytic Perturbation Theory, and 2 delta and 3 delta analytic QCD (AQCD) versions. In contrast to pQCD, these QCD variants do not have Landau singularities at low positive Q(2). In general, when 2 delta and 3 delta QCD coupling is used the fitted curves give the best results.