  Correlations between non-identical particles at small relative velocity probe
asymmetries in the average space-time emission points at freeze-out. The origin
of such asymmetries may be from long-lived resonances, bulk collective effects,
or differences in the freeze-out scenario for the different particle species.
STAR has extracted pion-proton correlation functions from a dataset of Au+Au
collisions at $\sqrt{s_{NN}}=200$ $GeV$. We present correlation functions in
the spherical harmonic decomposition representation, for different centralities
and for different combinations of pions and (anti-)protons.
