Chan-Paton Soliton Gauge States of Compatified Open String

TL;DR

This paper investigates the emergence of enhanced massive gauge symmetries in bosonic open strings compactified on a torus, highlighting the role of zero-norm soliton gauge states at specific massive levels and radii.

Contribution

It reveals that soliton gauge states only appear at massive levels and connect to enhanced gauge symmetries involving Einstein and Yang-Mills indices, differing from closed string cases.

Findings

Soliton gauge states exist only at massive levels in open strings.

Enhanced gauge symmetries occur at specific radii when D-branes are coincident.

These symmetries involve both Einstein and Yang-Mills indices.

Abstract

We study the mechanism of enhanced gauge symmetry of bosonic open string compatified on torus by analyzing the zero-norm soliton (nonzero winding of wilson line) gauge states in the spectrum. Unlike the closed string case, we find that the soliton gauge state exists only at massive levels. These soliton gauge states correspond to the existence of enhanced massive gauge symmetries with transformation parameters containing both Einstein and Yang-Mills indices. In the T-dual picture, these symmetries exist only at some discrete values of compatified radii when N D-branes are coincident.