ϕMeson Production inπ−pandK−pInteractions from 3 to 6 GeV/c

Cross sections and density-matrix elements for ${\pi }^{-}p\to \varphi n$ have been measured for - $-t\lesssim 1.5$ ${\mathrm{GeV}}^2$ at 3, 4, 5, and 6 GeV/c, using the Argonne effective-mass spectrometer to observe the decay $\varphi \mathrm{}\left(1019\right)\mathrm{}\to K^{+}{K}^{-}$. This is the first observation of the reaction in this energy range. The remarkably flat differential cross section at 4 GeV/c and the strong energy dependence suggest a production mechanism not normally seen at these energies. Data on $K^{-}p\to \varphi \Lambda$ and $K^{-}p\to \varphi {\Sigma }^0$ from the same experiment are also presented.