====== TTP01-23 The next-to-next-to-leading Order QCD Corrections to the Photon Structure Functions ======
 
 
   <hidden TTP01-23  The next-to-next-to-leading Order QCD Corrections to the Photon Structure Functions >   The next-to-next-to-leading order (NNLO) corrections in massless perturbative
 QCD are derived for the parton distributions of the photon and the deep
 inelastic structure functions F_1^gamma and F_2^gamma. We present the full
 photonic coefficient functions at order alpha alpha_s and calculate the first
 six even-integer moments of the corresponding O(alpha alpha_s^2) photon-quark
 and photon-gluon splitting functions together with the moments of the alpha
 alpha_s^2 coefficient functions which enter only beyond NNLO. These results are
 employed to construct parametrizations of the splitting functions which prove
 to be sufficiently accurate at least for momentum fractions x >= 0.05. We also
 present explicit expressions for the transformation from the MS_bar to the
 DIS_gamma factorization scheme and write down the solution of the evolution
 equations. The numerical impact of the NNLO corrections is discussed in both
 schemes.
 </hidden>
|**S. Moch, J.A.M. Vermaseren and A. Vogt**  | 
|**      Nucl.Phys. B621 (2002) 413 **  |
| {{preprints:2001:ttp01-23.pdf|PDF}} {{preprints:2001:ttp01-23.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/0110331|arXiv]]   |
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