Speaker
Description
We calculate non-singlet quark operator matrix elements of deep-inelastic
scattering in the chiral limit including operators with total derivatives.
This extends previous calculations with zero-momentum transfer through the
operator vertex which provides the well-known anomalous dimensions for the
evolution of parton distributions, as well as calculations in off-forward kinematics exploiting conformal symmetry. Non-vanishing momentum-flow through the operator vertex leads to mixing
with total derivative operators under renormalization.
In the limit of a large number of quark flavors $n_f$, we determine the anomalous dimension matrix to fifth order in the $\overline{\mbox{MS}}$-scheme by exploiting consistency relations for the anomalous dimension matrix which follow from the renormalization
structure of the operators, combined with a direct calculation of the relevant diagrams up to fourth order.