A String Project in Multicolour QCD

TL;DR

This paper reviews evidence supporting the string (planar random surfaces) representation of multicolour QCD, focusing on the strong coupling expansion and its potential validity in the weak coupling phase of four-dimensional QCD.

Contribution

It introduces a modified strong coupling expansion using planar random surfaces applicable to four-dimensional QCD's weak coupling phase.

Findings

Evidence for string representation in multicolour QCD

Proposal of checks for the validity of the expansion

Explanation of the modified strong coupling expansion

Abstract

Some old and new evidence for the existence of the string (planar random surfaces) representation of multicolour QCD are reviewed. They concern the random surface representation of the strong coupling expansion in lattice multicolour gauge theory in any dimension. Our old idea of modified strong coupling expansion in terms of planar random surfaces, valid for the physical weak coupling phase of the four-dimensional QCD, is explained in detail. Some checks of the validity of this expansion are proposed. (The lectures given in the Trieste Spring School and Workshop-1993 on String Theory).