2011/01/28 by Adnan Bashir, A. Bashir, C. Calcaneo-Roldan +4 · 1 citation
Physics and Astronomy · #Chiral symmetry breaking #Coupling (piping) #Coupling constant #Fermion #Function (biology) #High-Energy Particle Collisions Research #Mass generation #Mathematical physics #Particle physics #Particle physics theoretical and experimental studies #Photon #Physics #Propagator #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Scaling #Symmetry breaking #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.83.033003
published as Phys.Rev.D83:033003,2011 · 5 pages, 5 figures
arxiv created 2011/01/28 · openalex publication_date 2011/02/11 · arxiv updated 2011/02/21 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We demonstrate that in unquenched quantum electrodynamics (QED), chiral symmetry breaking ceases to exist above a critical number of fermion flavors Nf. This is a necessary and sufficient consequence of the fact that there exists a critical value of electromagnetic coupling \ensuremathα beyond which dynamical mass generation gets triggered. We employ a multiplicatively renormalizable photon propagator involving leading logarithms to all orders in \ensuremathα to illustrate this. We study the flavor and coupling dependence of the dynamically generated mass analytically as well as numerically. We also derive the scaling laws for the dynamical mass as a function of \ensuremathα and Nf. Up to a multiplicative constant, these scaling laws are related through (\ensuremathα,\ensuremathαc)\ensuremath↔(1/Nf,1/Nfc). Calculation of the mass anomalous dimension \ensuremathγm shows that it is always greater than its value in the quenched case. We also evaluate the \ensuremathβ function. The criticality plane is drawn in the (\ensuremathα,Nf) phase space which clearly depicts how larger Nf is required to restore chiral symmetry for an increasing interaction strength.