Unexciting non-Abelian electric fields

Electric fields in QED are known to discharge due to Schwinger pair production of charged particles. Corresponding electric fields in non-Abelian theory are known to discharge due to the production of gluons. Yet electric flux tubes in QCD ought to be stable to the production of charged gluons as they confine quarks. We resolve this conundrum by finding electric field configurations in pure non-Abelian gauge theory in which the Schwinger process is absent and the electric field is protected against quantum dissipation. We comment on the implications for QCD flux tubes.

Figure 1

A sketch for the tunneling picture of Schwinger pair production. The Coulomb curves (small-dashed) show the Coulomb attractive potential between the pair of charges; the long dashed line shows the potential energy of the positive charge due to the external electric field, and the solid curves are the sum of the Coulomb and external electric potentials. Quantum fluctuations deep in the potential well with energy E can tunnel out and escape to infinity and would be interpreted as Schwinger particle pairs.