Masanori Okawa

Higher twist effects in asymptotically free gauge theories: The anomalous dimensions of four-quark operators

Abstract The anomalous dimensions of the four-quark operators of twist four in the Wilson expansion are evaluated to second order in perturbation theory. The spinor calculus greatly simplifies the treatment of the fermion spin. The physical relevance of our results in deep inelastic scattering is discussed.

Higher Twist Effects in Asymptotically Free Gauge Theories

Abstract The anomalous dimensions of the flavor octet, three-body operators of twist four are evaluated at the one-loop level. The calculation is complicated due to the appearance of gauge non-invariant operators which are needed to renormalize gauge invariant operators. The mixing problem of these operators is resolved by using the Ward identities derived through the Becchi-Rouet-Stora transformations. Some comments on the evaluation of the coefficient functions are also made.