An experiment using optical spark chambers and a neutron time-of-flight hodoscope has been performed at the Argonne National Laboratory on the reaction ${\pi }^{-}p\to {\omega }^{0}n$. The differential cross section and the experimentally accessible density-matrix elements were determined in the momentum transfer interval $0.05\le \mathrm{}\left|t\right|\mathrm{}\le 1.0$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ at each of three incident pion momenta 3.65, 4.50, and 5.50 GeV/c. Our results show the following general features: (1) a dip in the forward differential cross section for $\mathrm{}\left|t\right|\mathrm{}\le 0.2$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$, (2) a slope at larger momentum transfers which increases as the incident pion momentum increases, and (3) no dips in either $\frac{d\sigma }{\mathrm{dt}}$ or ${\rho }_{11}+{\rho }_{1-1}$, the natural-parity exchange combination, at $\mathrm{}\left|t\right|=0.6\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$.

• Received 30 May 1973

DOI:https://doi.org/10.1103/PhysRevD.8.2814