Duality symmetry of BFKL equation: reggeized gluons vs color dipoles

TL;DR

This paper demonstrates that the duality symmetry of the BFKL equation connects the color dipole and reggeized gluon formulations through a rotation in transverse space, extending to non-forward cases due to the kernel's special structure.

Contribution

It reveals the duality symmetry of the BFKL equation as a rotation in transverse space and extends this symmetry to non-forward cases based on kernel structure.

Findings

Duality symmetry links s-channel and t-channel formulations.

Non-forward BFKL Kernel can be expressed as a sum of three forward kernels.

Dual coordinates correspond to transverse coordinates of a non-diagonal dipole.

Abstract

We show that the duality symmetry of the BFKL equation can be interpreted as a symmetry under rotation of the BFKL Kernel in the transverse space from s-channel (color dipole model) to t-channel (reggeized gluon formulation). We argue that the duality symmetry holds also in the non-forward case due to a very special structure of the non-forward BFKL Kernel, which can be written as a sum of three forward BFKL Kernels. The duality symmetry is established by identifying the dual coordinates with the transverse coordinates of a non-diagonal dipole scattered off the target.