The colour octet representation of the non-forward BFKL Green function

TL;DR

This paper analyzes the infrared properties of the non-forward BFKL Green function in the color octet channel, comparing it with the singlet case and exploring implications for N=4 SYM amplitudes.

Contribution

It provides a detailed factorization of infrared divergences for the non-forward BFKL Green function in the octet channel and compares its properties with the singlet case.

Findings

Infrared divergences are factorized for the octet Green function.

Comparison between octet and singlet Green functions at various momentum transfers.

Relevance of the octet Green function in two-loop six-point MHV amplitude calculations.

Abstract

We factorize the infrared divergences of the non-forward BFKL Green function for a general t-channel projection of the color quantum numbers and study the properties of the infrared finite remainder in the case of color octet exchange. The octet Green function is compared with the singlet case for different values of the momentum transfer. The octet Green function plays an important role in the calculation of the finite remainder of the two-loop six-point MHV planar amplitude in N = 4 SYM as it was demonstrated by Bartels, Lipatov and one of us in http://arXiv.org/abs/arXiv:0802.2065 and http://arXiv.org/abs/arXiv:0807.0894. A comparison with regularizations preserving conformal invariance at large momentum transfer is shown.