LIMITS on THE COUPLING CONSTANT of HIGHER-DERIVATIVE ELECTROMAGNETISM

Abstract

We investigate a higher-derivative version of QED constructed by adding to the Maxwell's Lagrangian a term containing second-order derivatives of the electromagnetic potentials. The resulting Lagrangian, besides being gauge and Lorentz invariant, gives origin to local field equations that are linear in the field quantities. Two bounds on the coupling constant of this higher-order model are estimated: one of them is found using the measurements obtained on a lab experiment whose principal aim was to test the Coulomb's inverse square law, the other involves the computation of the anomalous magnetic moment of the electron in the framework of the aforementioned system. As a by-product of the calculations on the quantum limit, a bound on the Lee-Wick heavy photon mass of the same order of magnitude as the masses of the vectorial bosons found in nature, is obtained as well.