Gauge anomaly cancellation in chiral gauge theories

We consider chiral fermions interacting minimally with abelian and non-abelian gauge fields. Using a path integral approach and exploring the consequences of a mechanism of symmetry restoration, we show that the gauge anomaly has null expectation value in the vacuum for both cases (abelian and non-abelian). We argue that the same mechanism has no possibility to cancel the chiral anomaly, what eliminates competition between chiral and gauge symmetry at full quantum level. We also show that the insertion of the gauge anomaly in arbitrary gauge invariant correlators gives a null result, which points towards anomaly cancellation in the subspace of physical state vectors.

► Null vacuum expectation value of the gauge anomaly operator in chiral gauge theories.
► Emphasis on gauge invariance of bosonic measure in functional integral approach.
► Vanishing of insertion of the anomaly operator in gauge invariant correlation functions.
► Non-cancellation of the chiral anomaly operator.
► Different cancellation mechanisms in abelian and non-abelian cases.