Transverse Takahashi identities and their implications for gauge independent dynamical chiral symmetry breaking
| Autor: | Adnan Bashir, L. Albino, B. El Bennich, L. X. Gutiérrez Guerrero, Eduardo Rojas |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Nuclear Theory High Energy Physics::Lattice Multiplicative function FOS: Physical sciences Propagator Fermion Vertex (geometry) Nuclear Theory (nucl-th) High Energy Physics - Phenomenology Transverse plane High Energy Physics - Phenomenology (hep-ph) Explicit analysis Gauge theory Chiral symmetry breaking Mathematical physics |
| Zdroj: | Physical Review D. 100 |
| ISSN: | 2470-0029 2470-0010 |
| DOI: | 10.1103/physrevd.100.054028 |
| Popis: | In this article, we employ transverse Takahashi identities to impose valuable non-perturbative constraints on the transverse part of the fermion-photon vertex in terms of new form factors, the so called $Y_i$ functions. We show that the implementation of these identities is crucial in ensuring the correct local gauge transformation of the fermion propagator and its multiplicative renormalizability. Our construction incorporates the correct symmetry properties of the $Y_i$ under charge conjugation operation as well as their well-known one-loop expansion in the asymptotic configuration of incoming and outgoing momenta. Furthermore, we make an explicit analysis of various existing constructions of this vertex against the demands of transverse Takahashi identities and the previously established key features of quantum electrodynamics, such as gauge invariance of the critical coupling above which chiral symmetry is dynamically broken. We construct a simple example in its quenched version and compute the mass function as we vary the coupling strength and also calculate the corresponding anomalous dimensions $\gamma_m$. There is an excellent fit to the Miransky scalling law and we find $\gamma_m=1$ rather naturally in accordance with some earlier results in literature, using arguments based on Cornwall-Jackiw-Tomboulis effective potential technique. Moreover, we numerically confirm the gauge invariance of this critical coupling. Comment: 16 pages, 4 figures |
| Databáze: | OpenAIRE |
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