Properties of the Scale Invariant $O(g^4)$ Lipatov Kernel

Abstract

We study the scale-invariant $O(g^4)$ kernel which appears as an infra-red contribution in the BFKL evolution equation and is constructed via multiparticle $t$-channel unitarity. We detail the variety of Ward identity constraints and infra-red cancellations that characterize its infrared behaviour. We give an analytic form for the full non-forward kernel. For the forward kernel controlling parton evolution at small-x, we give an impact parameter representation, derive the eigenvalue spectrum, and demonstrate a holomorphic factorisation property related to conformal invariance. The results show that, at next-to-leading-order, the transverse momentum infra-red region may produce a strong reduction of the BFKL small-x behavior.

41 pages in latex, 16 figs. in a uu-encoded ps-file

References in corpus (1)

• The $O(g^4)$ Lipatov Kernels

Cited by in corpus (7)

• Energy Scale(s) and Next-to-leading BFKL Equation
• k-Factorization and Small-x Anomalous Dimensions
• k-Factorization and Impact Factors at Next-to-leading Level
• Gauge Theory High-Energy Behavior from J-Plane Unitarity
• Scale Invariant $O(g^4)$ Lipatov Kernels at Non-Zero Momentum Transfer
• NLO Conformal Symmetry in the Regge Limit of QCD
• t-channel Approach to Reggeon Interactions in QCD