Integral equation for spin dependent unintegrated parton distributions incorporating double ln^2(1/x) effects at low x

Abstract

In this paper we derive an integral equation for the evolution of unintegrated (longitudinally) polarized quark and gluon parton distributions. The conventional CCFM framework is extended at small x in order to incorporate the QCD expectations concerning the double ln^2(1/x) resummation at low x for the integrated distributions. Complete Altarelli-Parisi splitting functions are included, that makes the formalism compatible with the LO Altarelli-Parisi evolution at large and moderately small values of x. The obtained modified polarized CCFM equation is shown to be partially diagonalized by the Fourier-Bessel transform. Results of the numerical solution for this modified CCFM equation for the non-singlet quark distributions are presented.

24 pages, 3 figures, LaTeX, some discussion added, none of the results changed, version to appear in Phys. Rev. D

References in corpus (6)

• Unintegrated parton distributions
• Hadronic final state predictions from CCFM: the hadron-level Monte Carlo generator CASCADE
• Small x Phenomenology: Summary and Status
• Unintegrated generalised parton distributions
• Gluon Distribution Functions in the kT-factorization Approach
• A polarized version of the CCFM equation for gluons

Cited by in corpus (3)

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