Pionic parton distributions revisited
M. Glück - E. Reya - I. Schienbein
Institut für Physik, Universität Dortmund, D-44221 Dortmund, Germany
Received: 3 March 1999 / Revised version: 3 May 1999 / Published online: 15 July 1999
Using constituent quark model constraints we calculate the gluon and sea-quark content of pions solely in terms of their valence density (fixed by Drell-Yan data) and the known sea and gluon distributions of the nucleon, using the most recent updated valence-like input parton densities of the nucleon. The resulting small-x dynamical QCD predictions for and are unique and parameter free. Simple analytic parametrizations of the resulting parton distributions of the pion are presented in LO and NLO. These results and parametrizations will be important, among other things, for updated formulations of the parton distributions of real and virtual photons.