QCD Fishnets Revisited

TL;DR

This paper revisits the fishnet diagram approach to approximating large N_c QCD, refining discretization rules to better capture QCD interactions and exploring the potential for a physically meaningful QCD string model.

Contribution

It introduces refined discretization rules for fishnet models that better preserve QCD interactions and explores their implications for modeling QCD as a string theory.

Findings

Refined discretization rules improve QCD interaction retention.

Fishnet diagrams are more complex and harder to evaluate than previous models.

Analysis of scalar and QCD fishnets demonstrates increased structural richness.

Abstract

We look back at early efforts to approximate the large N_c Feynman diagrams of QCD as very large fishnet diagrams. We consider more carefully the uniqueness of rules for discretizing P^+ and ix^+ which fix the fishnet model in the strong 't Hooft coupling limit, and we offer some refinements that allow more of the crucial QCD interactions to be retained in the fishnet approximation. This new discretization has a better chance to lead to a physically sensible `bare QCD string' model. Not surprisingly the resulting fishnet diagrams are both richer in structure and harder to evaluate than those considered in older work. As warm-ups we analyze arbitrarily large fishnets of a paradigm scalar cubic theory and very small fishnets of QCD.