The Dual Quark Models

TL;DR

This paper reviews the historical development of dual quark models, highlighting key theoretical advances in string theory, affine Lie algebras, and vertex operators from the early 1970s.

Contribution

It summarizes pioneering constructions of current-algebraic symmetries on the open string, including world sheet fermions and affine Lie algebra discoveries.

Findings

Introduction of world sheet fermions

Discovery of affine Lie algebra in physics

Development of vertex-operator constructions

Abstract

We briefly recall the historical environment around our 1971 and 1975 constructions of current-algebraic internal symmetry on the open string. These constructions included the introduction of world sheet fermions, the independent discovery of affine Lie algebra in physics (level one of affine su(3)), the first examples of the affine-Sugawara and coset constructions, and finally - from compactified spatial dimensions on the string - the first vertex-operator constructions of the fermions and level one of affine su(n).