  We show that QCD4 with transverse confinement can be approximately
compactified into QCD2 with a transverse quark mass $m_{{}_T}$ that is obtained
by solving a set of coupled transverse eigenvalue equations. In the limits of a
strong coupling and a large number of flavors, QCD2 further admits Schwinger
QED2-type bosonized solutions. We therefore examine phenomenologically the
space-time dynamics of produced particles in string fragmentation by studying
the Wigner function of produced bosons in Schwinger QED2, which mimics many
features of string fragmentation in quantum chromodynamics. We find that
particles with momenta in different regions of the rapidity plateau are
produced at the initial moment of string fragmentation as a quark pulls away
from an antiquark at high energies, in contrast to classical pictures of string
fragmentation with longitudinal space-momentum-time ordering.
