Beyond symmetries: Anomalies in transverse Ward-Takahashi identities

Abstract

Anomalies in transverse Ward-Takahashi identities are studied, allowing discussion of the feasibility of anomalies arising in general nonsymmetry Ward-Takahashi identities. We adopt the popular Fujikawa method and rigorous dimensional renormalization to verify the existence of transverse anomalies to oneloop order and any loop order, respectively. The arbitrariness of coefficients of transverse anomalies is revealed, and a way out is also proposed after relating transverse anomalies to Schwinger terms and comparing symmetry and nonsymmetry anomalies. Papers that claim the nonexistence of transverse anomalies are reviewed to find anomalies hidden in their approaches. The role played by transverse anomalies is discussed.