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arXiv · 1112.3476

Resummations in the Bloch-Nordsieck model

A. Jakovac·P. Mati
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Abstract

We studied different levels of resummations of the exactly solvable Bloch-Nordsieck model in order to be able to compare the approximations with an exact result. We studied one-loop perturbation theory, 2PI resummation and Schwinger-Dyson equations truncated in a way to maintain Ward-identities. At all levels we carefully performed renormalization. We found that although the 2PI resummation does not exhibit infrared sensitivity at the mass shell (the one-loop perturbation theory does), but it is still far from the exact solution. The method of truncated Schwinger-Dyson equations, however, is exact in this model, so it provides a new way of solving the Bloch-Nordsieck model. This method can also be generalized to other, more complicated theories.

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A. Jakovac, P. Mati. 2011-12-15. Resummations in the Bloch-Nordsieck model. https://doi.org/10.1103/physrevd.85.085006

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