  This report describes the transitions pion -> meson_1 + meson_2 and also pion
-> multi-pion for high energy pions interacting with target nuclei (Z,A). The
physics interests are: A) Nuclear inelastic coherent diffraction cross sections
for pions, for studies of size fluctuations in the pion wave function. B)
Radiative widths of excited meson states, for tests of vector dominance and
quark models. C) Experimental determination of the pi- + rho -> pi- + gamma
total reaction rate for gamma production above 0.7 GeV, needed for background
studies of quark-gluon plasma formation experiments. D) Investigation of the
gamma ->3 pi vertex in pion pair production by a pion, for a significantly
improved test of the hypothesis of chiral anomalies. The physics interest and
associated bibliography are summarized here; with particular reference to the
200-600 GeV beams available at FNAL and CERN. Complementary GEANT simulations
and trigger studies are needed.
