DOI 10.1007/s100520000529
Estimating the effect of NNLO contributions
on global parton analyses
A.D. Martin1 - R.G. Roberts2 - W.J. Stirling1,3 - R.S. Thorne4
1 Department of Physics, University of Durham, Durham, DH1 3LE, UK
2 Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, UK
3 Department of Mathematical Sciences, University of Durham, Durham, DH1 3LE, UK
4 Jesus College, University of Oxford, Oxford, OX1 3DW, UK
Received: 7 September 2000 / Published online: 13 November 2000 - © Springer-Verlag 2000
Abstract
We use the recent estimates of NNLO splitting functions,
made by van Neerven and Vogt, to
perform exploratory fits to deep inelastic and related
hard scattering data. We investigate the
hierarchy of parton distributions obtained at LO, NLO and NNLO, and,
more important, the
stability of the resulting predictions for physical observables.
We use the longitudinal
structure function FL and the cross sections
for W and Z hadroproduction as examples.
For FL we find relatively poor convergence, with
increasing order, at small x; whereas
are much more reliably predicted.
Copyright Società Italiana di Fisica, Springer-Verlag 2000
