On the next-to-next-to-leading order QCD corrections to heavy-quark production in deep-inelastic scattering

Understand

The contribution of quarks with masses m >> Lambda_QCD is the only part of the structure functions in deep-inelastic scattering (DIS) which is not yet known at the next-to-next-to-leading order (NNLO) of perturbative QCD.

• We present improved partial NNLO results for the most important structure function F_2(x,Q^2) near the partonic threshold, in the high-energy (small-x) limit and at high scales Q^2 >> m^2; and employ these results to construct approximations for the gluon and quark coefficient functions which cover the full kinematic plane.
• The approximation uncertainties are carefully investigated, and found to be large only at very small values, x smaller about 10^-3, of the Bjorken variable.