An Action For Chan-Paton Factors

TL;DR

This paper derives Chan-Paton factors from a classical boundary action for open strings, unifying their treatment in free, interacting, and gauge-coupled cases, and reproduces known results.

Contribution

It introduces a classical action framework for Chan-Paton factors, providing a new perspective on their origin and coupling in string theory.

Findings

Derived Chan-Paton factors from a boundary action

Unified treatment of free, interacting, and gauge-coupled strings

Recovered known results in string and gauge interactions

Abstract

We show that Chan-Paton factors can be derived from a classical action describing the dynamics of a new group-valued degree of freedom attached to the boundary of an open bosonic string. We discuss the free and the interacting string in the oriented and unoriented cases, as well as the coupling of the string to an external Yang-Mills gauge field, and recover by this approach well-known results.