Speaker
Description
We have calculated the $n_f^2$ and $n_f^3$ contributions to the flavour non-singlet structure functions $F_2$ and $F_L$ and most recently $F_3$ in inclusive deep-inelastic scattering at the fourth order in the strong coupling $\alpha_s$. The coefficient functions have been obtained by computing a very large number of Mellin-N moments using the method of differential equations, and then determining the analytic forms in N and Bjorken-x from these. Our new $n_f^2$ terms are numerically much larger than the n3f leading large-nf parts which were already known; they agree with predictions of the threshold and high-energy resummations. Furthermore, our calculation confirms the earlier determination of the four-loop $n_f^2$ part of the corresponding anomalous dimension.
