Third-order QCD corrections to the charged-current structure function image Original Research Article

We compute the coefficient function for the charge-averaged image-exchange structure function image in deep-inelastic scattering (DIS) to the third order in massless perturbative QCD. Our new three-loop contribution to this quantity forms, at not too small values of the Bjorken variable x, the dominant part of the next-to-next-to-next-to-leading order corrections. It thus facilitates improved determinations of the strong coupling image and of image power corrections from scaling violations measured in neutrino–nucleon DIS. The expansion of image in powers of image is stable at all values of x relevant to measurements at high scales image. At small x the third-order coefficient function is dominated by diagrams with the colour structure image not present at lower orders. At large x the coefficient function for image is identical to that of image up to terms vanishing for image.