  The possible link between entanglement and thermalization, and the dynamics
of hadronization are addressed by studying the real-time response of the
massive Schwinger model coupled to external sources. This setup mimics the
production and fragmentation of quark jets, as the Schwinger model and QCD
share the properties of confinement and chiral symmetry breaking. By using
quantum simulations on classical hardware, we study the entanglement between
the produced jets, and observe the growth of the corresponding entanglement
entropy in time. This growth arises from the increased number of contributing
eigenstates of the reduced density matrix with sufficiently large and close
eigenvalues. We also investigate the physical nature of these eigenstates, and
find that at early times they correspond to fermionic Fock states. We then
observe the transition from these fermionic Fock states to meson-like bound
states as a function of time. In other words, we observe how hadronization
develops in real time. At late times, the local observables at mid-rapidity
(such as the fermion density and the electric field) approach approximately
constant values, suggesting the onset of equilibrium and approach to
thermalization.
