  Identifying hadronic molecular states and/or hadrons with multi-quark
components either with or without exotic quantum numbers is a long standing
challenge in hadronic physics. We suggest that studying the production of these
hadrons in relativistic heavy ion collisions offer a promising resolution to
this problem as yields of exotic hadrons are expected to be strongly affected
by their structures. Using the coalescence model for hadron production, we find
that compared to the case of a non-exotic hadron with normal quark numbers, the
yield of an exotic hadron is typically an order of magnitude smaller when it is
a compact multi-quark state and a factor of two or more larger when it is a
loosely bound hadronic molecule. We further find that due to the appreciable
numbers of charm and bottom quarks produced in heavy ion collisions at RHIC and
even larger numbers expected at LHC, some of the newly proposed heavy exotic
states could be produced and realistically measured in these experiments.
