QCD sum rule calculation of twist-3 contributions to polarized nucleon structure functions

Using the framework of QCD sum rules we predict the twist-3 contribution to the second moment of the polarized nucleon structure function g2(x). As the relevant local operator depends explicitly on the gluon field, we employ a recently studied interpolating nucleon current which contains three quark field and one gluon field operator. Despite the fact that our calculation is based on the analysis of a completely different correlation function, our estimates are consistent with those of Balitsky, Braun and Kolesnichenko who used a three-quark current.