Vacuum Polarization and the Electric Charge of the Positron

Abstract

We show that higher-order vacuum polarization would contribute a measureable net charge to atoms, if the charges of electrons and positrons do not balance precisely. We obtain the limit $|Q_e+Q_{\bar{e}}|<10^{-18}e$ for the sum of the charges of electron and positron. This also constitutes a new bound on certain violations of PCT invariance.

9 pages, 1 figure attached as PostScript file, DUKE-TH-92-38. Revised version