DOKSHITZER–GRIBOV–LIPATOV–ALTARELLI–PARISI EVOLUTION AND THE RENORMALIZATION GROUP IMPROVED YENNIE–FRAUTSCHI–SUURA THEORY IN QCD

Abstract

We show that the recently derived renormalization group improved Yennie–Frautschi–Suura (YFS) exponentiation of soft (k0→0) gluons in QCD is fully compatible with the usual Dokshitzer–Gribov–Lipatov–Altarelli–Parisi (DGLAP) evolution of the structure functions of hadrons in the respective hadron–hadron hard interactions. We show how to implement the YFS exponentiation without double or over counting effects already implied by the DGLAP equation. In this way, we arrive at a theory which allows for the development of realistic, multiple gluon Monte–Carlo event generators for hard hadron–hadron scattering processes in which the DGLAP evolved structure functions are correctly synthesized with the respective YFS exponentiated soft gluon effects in a rigorous way.