Abreu, EMCDalmazi, D.Dutra, Alvaro de Souza [UNESP]Hott, M.2014-05-202014-05-202002-06-15Physical Review D. College Pk: American Physical Soc, v. 65, n. 12, 5 p., 2002.0556-2821http://hdl.handle.net/11449/9095In this work we discuss the effect of the quartic fermion self-interaction of Thirring type in QED in D=2 and D=3 dimensions. This is done through the computation of the effective action up to quadratic terms in the photon field. We analyze the corresponding nonlocal photon propagators nonperturbatively in k/m, where k is the photon momentum and m the fermion mass. The poles of the propagators were determined numerically by using the MATHEMATICA software. In D=2 there is always a massless pole whereas for strong enough Thirring coupling a massive pole may appear. For D=3 there are three regions in parameter space. We may have one or two massive poles or even no pole at all. The interquark static potential is computed analytically in D=2. We notice that the Thirring interaction contributes with a screening term to the confining linear potential of massive two-dimensional QED (QED(2)). In D=3 the static potential must be calculated numerically. The screening nature of the massive QED(3) prevails at any distance, indicating that this is a universal feature of D=3 electromagnetic interaction. Our results become exact for an infinite number of fermion flavors.5engArtigo10.1103/PhysRevD.65.125030WOS:000176771700089Acesso abertoWOS000176771700089.pdf82793938764156086314084638411003