The polarized two-loop massive pure singlet Wilson coefficient for deep-inelastic scattering

摘要

We calculate the polarized massive two–loop pure singlet Wilson coefficient contributing to the structure functionsg1(x,Q2)analytically in the whole kinematic region. The Wilson coefficient contains Kummer–elliptic integrals. We derive the representation in the asymptotic regionQ2?m2, retaining power corrections, and in the threshold region. The massless Wilson coefficient is recalculated. The corresponding twist–2 corrections to the structure functiong2(x,Q2)are obtained by the Wandzura–Wilczek relation. Numerical results are presented.