Irreducible part of the next-to-leading BFKL kernel

On the basis of previous work by Fadin, Lipatov, and collaborators, and by our group, we extract the ''irreducible'' part of the next-to-leading (NL) BFKL kernel, we compute its (IR finite) eigenvalue function, and we discuss its implications for small-x structure functions. We find consistent running coupling effects and sizeable NL corrections to the Pomeron intercept and to the gluon anomalous dimension. The qualitative effect of such corrections is to smooth out the small-x rise of structure functions at low values of Q(2). A more quantitative analysis will be possible after the extraction of some additional, energy-scale dependent contributions to the kernel, which are not treated here. (C) 1997 Elsevier Science B.V.