Dynamical parton distribution functions

Abstract

Recent measurements for F_2(x,Q^2) have been analyzed in terms of the `dynamical' and `standard' parton model approach at NLO and NNLO of perturbative QCD. Having fixed the relevant NLO and NNLO parton distributions, the implications and predictions for the longitudinal structure function F_L(x,Q^2) are presented. It is shown that the previously noted extreme perturbative NNLO/NLO instability of F_L(x,Q^2) is an artifact of the commonly utilized `standard' gluon distributions. In particular it is demonstrated that using the appropriate -- dynamically generated -- parton distributions at NLO and NNLO, F_L(x,Q^2) turns out to be perturbatively rather stable already for Q^2 \geq O(2-3 GeV^2).

9 pages, 7 figures, 2 tables, invited talk given at Ringberg Workshop: New Trends in HERA Physics 2008, Ringberg Castle, Tegernsee, Germany, 5-10 October 2008

References in corpus (10)

• Dynamical parton distributions of the nucleon and very small-x physics
• Heavy Quark Mass Effects in Deep Inelastic Scattering and Global QCD Analysis
• Fixed target Drell-Yan data and NNLO QCD fits of parton distribution functions
• A Global Fit to Scattering Data with NLL BFKL Resummations
• The Longitudinal Heavy Quark Structure Function F_{L}^{Q\bar{Q}} in the Region Q^2 \gg m^2 at O(α_s^3)
• Non-singlet QCD analysis of F_2(x,Q^2) up to NNLO
• The role of F_L(x,Q^2) in parton analyses
• Dynamical NNLO parton distributions and the perturbative stability of F_L(x,Q^2)
• The curvature of $F_2^p(x,Q^2)$ as a probe of the range of validity of perturbative QCD evolutions in the small-$x$ region
• Parton evolution in the fixed flavor factorization scheme

Cited by in corpus (3)

• Determination of pion and kaon fragmentation functions including spin asymmetries data in a global analysis
• Extracting the longitudinal structure function FL(x,Q2) at small x from a Froissart-bounded parametrization of F2(x,Q2)
• New parton distributions in fixed flavour factorization scheme from recent deep-inelastic-scattering data