  The Schwinger confinement mechanism stipulates that a massless fermion and a
massless antifermion are confined as a massive boson when they interact in the
Abelian QED interaction in (1+1)D. If we approximate light quarks as massless
and apply the Schwinger confinement mechanism to quarks, we can infer that a
light quark and a light antiquark interacting in the Abelian QED interaction
are confined as a QED meson in (1+1)D. Similarly, a light quark and a light
antiquark interacting in the QCD interaction in the quasi-Abelian approximation
will be confined as a QCD meson in (1+1)D. The QED and QCD mesons in (1+1)D can
represent physical mesons in (3+1)D when the flux tube radius is properly taken
into account. Such a theory leads to a reasonable description of the masses of
$\pi^0, \eta$, and $ \eta'$, and its extrapolation to the unknown QED sector
yields an isoscalar QED meson at about 17 MeV and an isovector QED meson at
about 38 MeV. The observations of the anomalous soft photons, the hypothetical
X17 particle, and the hypothetical E38 particle bear promising evidence for the
possible existence of the QED mesons. Pending further confirmation, they hold
important implications on the properties on the quarks and their interactions.
