Speaker
Description
It is well known that light-front field theories suffer from the appearance of higher-order poles when treated in Feynman's approach to perturbative quantum field theory, originated in the non-local terms which arise in Feynman's propagators of some fields in light-front dynamics. The regularization of these terms is a delicate issue, as there are many prescriptions to do it. In null-plane causal perturbation theory, which is a rigorous approach to Heisenberg's S-matrix program in light-front dynamics, on the other hand, Feynman's propagators do not appear in loop calculations, but only the positive- and negative-frequency parts of the commutation distributions of the quantized fields. Consequently, no spurious poles appear in loop distributions, which are ultra-violet finite by construction, allowing to establish the equivalence with instant dynamics in a very clear way. We exemplify loop calculations in the causal approach in Yukawa's model as well as in QED.
References
[1] H. Epstein and V. Glaser. The role of locality in perturbation theory. Ann. Inst. H. Poincaré A 19: 211-295 (1973).
[2] G. Scharf. Finite Quantum Electrodynamics. The Causal Approach. 3th Edition. Dover (2014).
[3] O.A. Acevedo, B.M. Pimentel and D.E. Soto. Epstein-Glaser's Causal Light-Front Field Theory. Proc. Sci., LC2019: 021 (2020).
[4] O.A. Acevedo and B.M. Pimentel. Null-plane causal perturbation theory. Submitted.
[5] O.A. Acevedo and B.M. Pimentel. Radiative corrections in the Yukawa model within the null-plane causal perturbation theory framework. Phys. Rev. D 103: 076022 (2021).
[6] O.A. Acevedo, J. Beltrán, B.M. Pimentel and D.E. Soto. Causal perturbation theory approach to Yukawa's model. Eur. Phys. J. Plus 136: 895 (2021).
[7] O.A. Acevedo and B.M. Pimentel. Quantum electrodynamics in the null-plane causal perturbation theory I. In preparation.
