  Processes that break molecular bonds are typically observed with molecules
occupying a mixture of quantum states and successfully described with
quasiclassical models, while a few studies have explored the distinctly quantum
mechanical low-energy regime. Here we use photodissociation of diatomic
strontium molecules to demonstrate the crossover from the ultracold, quantum
regime where the photofragment angular distributions strongly depend on the
kinetic energy, to the energy-independent quasiclassical regime. Using
time-of-flight velocity map imaging for photodissociation channels with
millikelvin reaction barriers, we explore photofragment energies in the 0.1-300
mK range experimentally and up to 3 K theoretically, and discuss the energy
scale at which the crossover occurs. Furthermore, we find that the effects of
quantum statistics can unexpectedly persist to high photodissociation energies.
