O( αs2) contributions to charm production in charged-current deep-inelastic lepton-hadron scattering
The most important part of the order αs2 corrections to the charm component of the charged-current structure functions F2 ( x, Q2) and F3 ( x, Q2) has been calculated. This calculation is based on the asymptotic form of the heavy-quark coefficient functions corresponding to the higher order corrections to the W-boson-gluon fusion process. These coefficient functions, which are in principle only valid for Q2 ≫ m2, can also be used to estimate the order αs2 contributions at lower Q2 values provided x < 0.1. It turns out that the above corrections are appreciable in the large Q2 region and they explain the discrepancy found for the structure functions between the fixed-flavour scheme (FFS) and the variable-flavour-number scheme (VFNS). These corrections also hamper the extraction of the strange-quark density from the data obtained for the charged-current and the electromagnetic-current processes.