ENERGY SCALE AND COHERENCE EFFECTS IN SMALL-X EQUATIONS

I consider the next-to-leading high-energy cluster expansion of large- k double jet production in QCD, and I determine the corresponding one- loop quark and gluon impact factors for a self-consistent energy scale . The result shows that coherent angular ordering of emitted gluons ho lds for hard emission also, and singles out a scale which in essential ly the largest virtuality in the process. Both remarks are relevant fo r the precise determination of the BFKL kernel at the next-to-leading level. (C) 1998 Elsevier Science B.V. All rights reserved.