4D Anomalous U(1)'s, their masses and their relation to 6D anomalies

TL;DR

This paper explains how certain U(1) gauge fields in 4D string models become massive due to underlying 6D anomalies, linking higher-dimensional anomalies to 4D mass generation through decompactification effects.

Contribution

It reveals the connection between 4D U(1) masses and 6D anomalies, providing a new understanding of anomaly-induced mass mechanisms in string compactifications.

Findings

4D anomaly-free U(1)s can still be massive due to 6D anomalies

6D anomalies influence 4D masses via decompactification

The study clarifies the role of higher-dimensional anomalies in 4D gauge mass generation

Abstract

In some four-dimensional orientifolds, U(1) gauge fields that are free of four-dimensional anomalies can still be massive. It is shown that this is due to mass-generating six-dimensional anomalies. Six-dimensional anomalies affect four-dimensional masses via decompactifications.