Multiple Reggeon Exchange from Summing QCD Feynman Diagrams

Abstract

Multiple reggeon exchange supplies subleading logs that may be used to restore unitarity to the Low-Nussinov Pomeron, provided it can be proven that the sum of Feynman diagrams to all orders gives rise to such multiple regge exchanges. This question cannot be easily tackled in the usual way except for very low-order diagrams, on account of delicate cancellations present in the sum which necessitate individual Feynman diagrams to be computed to subleading orders. Moreover, it is not clear that sums of high-order Feynman diagrams with complicated criss-crossing of lines can lead to factorization implied by the multi-regge scenario. Both of these difficulties can be overcome by using the recently developed nonabelian cut diagrams. We are then able to show that the sum of $s$-channel-ladder diagrams to all orders does lead to such multiple reggeon exchanges.

uu-encoded latex file with 11 postscript figures (20 pages)

References in corpus (1)

• Gluon Regge Trajectory in the two-loop Approximation

Cited by in corpus (10)

• Decomposition of Time-Ordered Products and Path-Ordered Exponentials
• Consistency of the Baryon-Multimeson Amplitudes for Large-N_c QCD
• Bose-Einstein Interference in the Passage of a Jet in a Dense Medium
• Unitarized Diffractive Scattering in QCD and Application to Virtual Photon Total Cross Sections
• Feynman Amplitude Approach to study the Passage of a Jet in a Medium
• Small-Recoil Approximation
• Occam's Higgs: A Phenomenological Solution to the Electroweak Hierarchy Problem
• Novel Bose-Einstein Interference in the Passage of a Fast Particle in a Dense Medium
• Evaluation of Multiloop Diagrams via Lightcone Integration
• Implementing Unitarity in Perturbation Theory