https://doi.org/10.1140/epjc/s10052-024-12766-x
Regular Article - Theoretical Physics
Fermionic fixed-point structure of asymptotically safe QED with a Pauli term
1
Theoretisch-Physikalisches Institut, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743, Jena, Germany
2
Helmholtz-Institut Jena, Fröbelstieg 3, 07743, Jena, Germany
3
GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, 64291, Darmstadt, Germany
Received:
13
March
2024
Accepted:
4
April
2024
Published online:
8
May
2024
We test the physical viability of a recent proposal for an asymptotically safe modification of quantum electrodynamics (QED), whose ultraviolet physics is dominated by a non-perturbative Pauli spin-field coupling. We focus in particular on its compatibility with the absence of dynamical generation of fermion mass in QED. Studying the renormalization group flow of chiral four-fermion operators and their fixed points, we discover a distinct class of behavior compared to the standard picture of fixed-point annihilation at large gauge couplings and the ensuing formation of chiral condensates. Instead, transcritical bifurcations, where the fixed points merely exchange infrared stability, are observed. Provided that non-chiral operators remain irrelevant, our theory accommodates a universality class of light fermions for 
irreducible Dirac flavors. On the contrary, in the special case of 
flavor, this comes only at the expense of introducing one additional relevant parameter.
© The Author(s) 2024
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