QCD SUM-RULE CALCULATION OF TWIST-4 CORRECTIONS TO BJORKEN AND ELLIS-JAFFE SUM-RULES

We calculate the twist-4 corrections to the integral of g(1)(x, Q(2)) in the framework of QCD sum rules using an interpolating nucleon field which contains explicitly a gluonic degree of freedom. This informati on can be used together with previous calculations of the twisr-3 cont ribution to the second moment of g(2)(x) to estimate the higher-twist corrections to the Ellis-Jaffe and Bjorken sum rules. We get f((2)) (p roton) = -0.037 +/- 0.006 and f((2)) (neutron) = -0.013 +/- 0.006. Num erically our results roughly agree with those obtained by Balitsky, Br aun and Kolesnichenko based on a sum rule for a simpler current. Our c alculations are far more stable as tested within the sum rule approach but are more sensitive to less well known condensates.