Renormalization Group Improved Small-x Equation

Abstract

We propose and analyze an improved small-x equation which incorporates exact leading and next-to-leading BFKL kernels on one hand and renormalization group constraints in the relevant collinear limits on the other. We work out in detail the recently proposed omega-expansion of the solution, derive the Green's function factorization properties and discuss both the gluon anomalous dimension and the hard pomeron. The resummed results are stable, nearly renormalization-scheme independent, and join smoothly with the fixed order perturbative regime. Two critical hard pomeron exponents are provided, which - for reasonable strong-coupling extrapolations - are argued to provide bounds on the pomeron intercept.