Soft emissions and the equivalence of BFKL and CCFM final states

TL;DR

This paper shows that BFKL and CCFM equations produce equivalent predictions for final-state observables at leading order, emphasizing the importance of soft emission treatment in CCFM.

Contribution

It demonstrates the equivalence of BFKL and CCFM equations for final states, including a novel approach to soft emission in CCFM.

Findings

BFKL and CCFM yield identical results at leading order

Soft emission treatment is crucial for CCFM equivalence

Provides a unified understanding of small-x evolution equations

Abstract

This article demonstrates that the BFKL and CCFM equations, despite their different physical content, lead to equivalent results for any final-state observable at leading single-logarithmic order. A novel and fundamental element is the treatment also of the soft (z->1 divergent) part of the splitting function in the CCFM equation.