The next-to-leading order jet vertex for Mueller-Navelet and forward jets revisited

We recalculate, completely within the original BFKL approach and at the next-to-leading order, the jet vertex relevant for the production of Mueller-Navelet jets in proton collisions and of forward jets in DIS. We consider both processes with incoming quark and gluon. The starting point is the definition of quark and gluon impact factors in the BFKL approach. Following this procedure we show explicitly that all infrared divergences cancel when renormalized parton densities are considered. We compare our results for the vertex with the former calculation of Refs. [1,2] and, in the case of the quark contribution, clarify the discrepancy present in the literature.
Comment: 28 pages, 3 figures; a few references added; modified Abstract, Introduction and Summary to take into account that the equivalence between the results of Bartels et al. (Refs.[1,2]) and those of Colferai et al. (Ref.[23]) has been established