  The physical processes behind the production of light nuclei in heavy ion
collisions are unclear. The nice theoretical description of experimental yields
by thermal models conflicts with the very small binding energies of the
observed states, being fragile in such a hot and dense environment. Other
available ideas are delayed production via coalescence, or a cooling of the
system after the chemical freeze-out according a Saha equation, or a `quench'
instead of a thermal freeze-out. A recently derived prescription of an
(interacting) Hagedorn gas is applied to consolidate the above pictures. The
tabulation of decay rates of Hagedorn states into light nuclei allows to
calculate yields usually unaccessable due to very poor Monte Carlo statistics.
Decay yields of stable hadrons and light nuclei are calculated. While the
scale-free decays of Hagedorn states alone are not compatible with the
experimental data, a thermalized hadron and Hagedorn state gas is able to
describe the experimental data. Applying a cooling of the system according a
Saha-equation with conservation of nucleons and anti-nucleons in number leads
to (nearly) temperature independent yields, thus a production of the light
nuclei at temperatures much lower than the chemical freeze-out temperature is
possible.
