The proton's gluon distribution
  The gluon distribution is dominated by the hard pomeron at small $x$ and all $Q^2$, with no soft-pomeron contribution. This describes well not only the DGLAP evolution of the hard-pomeron part of $F_2(x,Q^2)$, but also charm photoproduction and electroproduction, and the longitudinal structure function, all calculated in leading-order pQCD. 
A Donnachie and P V Landshoff