We show that reactive molecules with a unit probability of reaction naturally
provide a simulator of some intriguing black hole physics. The unit reaction at
the short distance acts as an event horizon and delivers a one-way traffic for
matter waves passing through the potential barrier when two molecules interact
by high partial-wave scatterings or dipole-dipole interactions. In particular,
the scattering rate as a function of the incident energy exhibits a
thermal-like distribution near the maximum of the interaction energy in the
same manner as a scalar field scatters with the potential barrier outside the
event horizon of a black hole. Such a thermal-like scattering can be extracted
from the temperature-dependent two-body loss rate measured in experiments on
KRb and other molecules.
