On Regge kinematics in SCET

TL;DR

This work analyzes Regge kinematics within Soft Collinear Effective Theory (SCET), showing that Reggeon exchange arises from an ordered sequence of collinear emissions connected by a Glauber-like rung. It identifies a multi-scale, ordered-collinear structure and explains how strong ordering yields a transverse-dominated, Reggeized behavior that challenging standard SCET power counting. The authors argue that extending SCET to accommodate Glauber exchanges and Regge degrees of freedom is necessary to faithfully describe Regge phenomena in QCD and to connect Regge-based phenomenology with SCET formalism.

Abstract

We discuss the kinematics of the particles that make up a Reggeon in field theory, using the terminology of the Soft Collinear Effective Theory (SCET). Reggeization sums a series of strongly-ordered collinear emissions resulting in an overall Reggeon exchange that falls in the Glauber or Coulomb kinematic region. This is an extremely multi-scale problem and appears to fall outside of the usual organizing scheme of SCET.

Figures (3)

• Figure 1: The ladder graphs
• Figure 2: The cut ladder graphs
• Figure 3: The discontinuity of the box diagram and of the three-rung diagram.