Ward-Takahashi identity in the light-front formalism for a bound state of fermions
Abstract
We investigate the Ward-Takahashi identity at one-loop in the light-front (LF) formalism for a bound state of fermions. We consider a spinless bound state made up of two fermions in which the Ward-Takahashi identity is satisfied in the covariant formulation. Considering the same system in the light-front formalism, we investigate the proof of Ward-Takahashi identity by integrating the light-front energy component through the identification of the relevant ranges of the longitudinal LF momentum. We elucidate that the pair production diagram plays a crucial role in establishing the Ward-Takahashi identity. We also point out the necessity of taking into account the corresponding zero modes for truly establishing the Ward-Takahashi identity in the LF formalism.
Fields of Study & Subjects
Quantum Chromodynamics and Particle Interactions
Cold Atom Physics and Bose-Einstein Condensates
Physics of Superconductivity and Magnetism
Publication details
- Journal / source
- Physical review. D/Physical review. D.
- Publisher
- American Physical Society (APS)
- Volume
- 113
- Issue
- 3
- Publication date
- 14 January 2026
- Language
- EN