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.
Keywords
Cite
@article{arxiv.hep-ph/0209041,
title = {Integral equation for spin dependent unintegrated parton distributions incorporating double ln^2(1/x) effects at low x},
author = {Jan Kwiecinski and Martin Maul},
journal= {arXiv preprint arXiv:hep-ph/0209041},
year = {2009}
}
Comments
24 pages, 3 figures, LaTeX, some discussion added, none of the results changed, version to appear in Phys. Rev. D