Evaluation of Bjorken polarised sum rule with a renormalon-motivated approach

We use the known renormalon structure of Bjorken polarised sum rule (BSR) to evaluate the leading-twist part of that quantity. In addition, we include and Operator Product Expansion (OPE) terms and fit this expression to available experimental data for inelastic BSR. Since we use perturbative QCD (pQCD) coupling, which fails at low squared spacelike momenta due to Landau singularities, the fit is performed for where. Due to large BSR experimental uncertainties, the extracted value of the pQCD coupling has very large uncertainties, especially when is varied. However, when we fix the pQCD coupling to the known world average values, the and residue parameters can be determined within large but reasonable uncertainties.