====== TTP02-22 Non-Singlet Structure Functions at Three Loops: Fermionic Contributions ======
 
 
   <hidden TTP02-22  Non-Singlet Structure Functions at Three Loops: Fermionic Contributions >        We compute the fermionic (n_f) contributions to the flavour
 non-singlet structure functions in unpolarized electromagnetic
 deep-inelastic scattering at third order of massless
        perturbative QCD. Complete results are presented for the
 corresponding nf-parts of the three-loop anomalous dimension and the
 three-loop coefficient functions for the structure
        functions F_2 and F_L. Our results agree with all partial and
 approximate results available in the literature. The present calculation
 also facilitates a complete determination of the
        threshold-resummation parameters B_2 and D_2^DIS of which only the
 sum was known so far, thus completing the information required for the
 next-to-next-to-leading logarithmic
        resummation. We find that D_2^DIS vanishes in the MSbar scheme.
 </hidden>
|**S. Moch, J.A.M. Vermaseren and A. Vogt**  | 
|**  Nucl.Phys.  B646 181-200 2002  **  |
| {{preprints:2002:ttp02-22.pdf|PDF}} {{preprints:2002:ttp02-22.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/0209100|arXiv]]   |
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