Infrared modified QCD couplings and Bjorken sum rule

We test the recently proposed "Massive" Perturbation Theory (MPT) for the description of the Gamma(p-n)(1) data at low momentum transfers. The MPT constructed on the two grounds: the first is pQCD with only one parameter added, an effective "glueball mass" m(p) less than or similar to M-gl less than or similar to 1 GeV; serving as an infrared "regulator"; the second stems out of the ghost-free Analytic Perturbation Theory comprising non-power perturbative expansion that makes it compatible with linear integral transformations. It is regular in the low-energy region and could serve as a practical means for the analysis of data below 1 GeV up to the IR-limit. We study the non-perturbative Bjorken sum rule higher twists correction by using the MPT, the integral representation for infinite sum of higher twists coefficients and the QCD-inspired model for the Q(2)-dependence of the generalized Gerasimov-Drell-Hearn sum rule.