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 contributi on to the second moment of the polarized nucleon structure function g( 2)(x). As the relevant local operator depends explicitly on the gluon field, we employ a recently studied interpolating nucleon current whic h contains three quark field and one gluon field operator. Despite the fact that our calculation is based on the analysis of a completely di fferent correlation function, our estimates are consistent with those of Balitsky, Braun and Kolesnichenko who used a three-quark current.