BFKL predictions at small x from k_T and collinear factorization viewpoints

Abstract

Hard scattering processes involving hadrons at small $x$ are described by a $k_T$-factorization formula driven by a BFKL gluon. We explore the equivalence of this description to a collinear-factorization approach in which the anomalous dimensions ${\gamma }_{gg}$ and ${\gamma }_{qg}/{\alpha }_S$ are expressed as power series in ${\alpha }_S\log (1/x)$, or to be precise ${\alpha }_S/\omega$ where $\omega$ is the moment index. In particular we confront the collinear-factorization expansion with that extracted from the BFKL approach with running coupling included.

Comments: 11 LaTeX pages, 1 figure (uuencoded)