Pauli-term-induced fixed points in d-dimensional QED

Abstract

AbstractWe explore the fixed-point structure of QED-like theories upon the inclusion of a Pauli spin-field coupling. We concentrate on the fate of UV-stable fixed points recently discovered in $$d=4$$ d = 4 spacetime dimensions upon generalizations to lower as well as higher dimensions for an arbitrary number of fermion flavors $$N_{\text {f}}.$$ N f . As an overall trend, we observe that going away from $$d=4$$ d = 4 dimensions and increasing the flavor number tends to destabilize the non-Gaussian fixed points discovered in four spacetime dimensions. A notable exception is a non-Gaussian fixed point at finite Pauli spin-field coupling but vanishing gauge coupling, which also remains stable down to $$d=3$$ d = 3 dimensions and for small flavor numbers. This includes also the range of degrees of freedom used in effective theories of layered condensed-matter systems. As an application, we construct renormalization group trajectories that emanate from the non-Gaussian fixed point and approach a long-range regime in the conventional QED$${}_3$$ 3 universality class that is governed by the interacting (quasi) fixed point in the gauge coupling.