  The study of confinement in quantum spin chains has seen a large surge of
interest in recent years. It is not only important for understanding a range of
effective one-dimensional condensed matter realizations, but also shares some
of the non-perturbative physics with quantum chromodynamics (QCD) which makes
it a prime target for current quantum simulation efforts. In analogy with QCD,
the confinement-induced two-particle boundstates that appear in these models
are dubbed mesons. Here, we study scattering events due to meson collisions in
a quantum spin chain with long-range interactions such that two mesons have an
extended interaction. We show how novel hadronic boundstates, e.g. with four
constituent particles akin to tetraquarks, may form dynamically in fusion
events. In a natural collision their signal is weak as elastic meson scattering
dominates. However, we propose two controllable protocols which allow for a
clear observation of dynamical hadron formation. We discuss how this physics
can be simulated in trapped ion or Rydberg atom set-ups.
