A clash between global chiral symmetries and gauge symmetry leads to anomalies. – External and internal anomalies. – Two faces of the anomaly. – The power of the ’t Hooft matching. – A brief encounter with the scale anomaly.
33 Chiral anomaly in the Schwinger model
Our first encounter with the chiral anomalies in gauge theories occurred in Chapter 5. We have invoked them, in a pragmatic way, more than once. The current chapter is designed to explain the conceptual issues behind the anomalies. The questions to be asked are ...