  We present preliminary results on the cross sections and Dalitz-plot
densities for the process pi- p -> pi0 pi0 n from threshold to p(pi)=750 MeV/c
as well as for K- p -> pi0 pi0 Lambda and K- p -> pi0 pi0 Sigma0 at p(K)=520 to
750 MeV/c. We have found that sigma(tot)(pi- p -> pi0 pi0 n) ~= 2sigma(tot)(K-
p -> pi0 pi0 Lambda). The pi0 pi0 n Dalitz plots are very nonuniform,
expecially for the higher p(pi), with a high concentration of events on an
"island" around m(pi n) ~= 1.2 GeV and Gamma ~= 0.1 GeV peaking at high pi0 pi0
invariant mass. This is indicative of the dominant role of the
Delta0(1234)(3/2^+) resonance in the final state.
  The pi0 pi0 Lambda Dalitz plots are strikingly similar to the ones for pi0
pi0 n except that the island is concentrated at m(pi Lambda) ~= 1.38 GeV and
has a narrower width, Gamma ~= 0.05 GeV. This indicates the dominant role of
the Sigma0(1385)(3/2+) resonance. The similarity in the Dalitz plots and the
proportionality of the total cross sections are an impressive testimony of the
applicability of broken SU(3) flavor symmetry to reaction dynamics. We have
measured sigma(tot)(K- p -> pi0 pi0 Lambda) ~= 6sigma(tot)(K- p -> pi0 pi0
Sigma0) and observed that the Dalitz plots for these processes are very
different. The Dalitz plots for pi0 pi0 Sigma0 show some enhancement at low pi0
pi0 invariant mass, and there is good indication for the Lambda(1405)
intermediate state but there is no island; at the highest p(K), there is some
evidence for the Lambda(1520) intermediate state. The above features of pi0 pi0
production by pi- and K- can all be understood if f0 production is small.
