Study of the Reactionsπ+p→K+Σ+andπ+p→K+Y*+(1385)Between 3.5 and 14 GeV/c

Measurements of the differential cross section for the reactions ${\pi }^{+}p\to K^{+}{\Sigma }^{+}$ and ${\pi }^{+}p\to K^{+}{Y}^{*+}\mathrm{}\left(1385\right)\mathrm{}$ are reported at 3.5, 3.75, 4.0, 4.25, 4.5, 4.75, 5.0, 6.0, 10.0, and 14.0 GeV/c. Polarization in ${\pi }^{+}p\to K^{+}{\Sigma }^{+}$ is also reported at 6.0, 10.0, and 14.0 GeV/c. At small $\mathrm{}\left|t\right|\mathrm{}$, the cross section for ${\pi }^{+}p\to K^{+}{\Sigma }^{+}$ is well described by an exponential $A{e}^{\mathrm{bt}}$ with slopes in the range $b\approx 8-10$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{-2\mathrm{}}$; for $\mathrm{}\left|t\right|>0.5\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ this slope decreases considerably. The cross section for ${\pi }^{+}p\to K^{+}{Y}^{*+}\mathrm{}\left(1385\right)\mathrm{}$ is well described for $\mathrm{}\left|t\right|>0.2\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ by a single exponential of slope about half that for ${\pi }^{+}p\to K^{+}{\Sigma }^{+}$; there is no break near $\mathrm{}\left|t\right|>0.5\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. We observe a dip in this cross section near $t=0\mathrm{}$. The polarization in ${\pi }^{+}p\to K^{+}{\Sigma }^{+}$ is consistent with zero for $\mathrm{}\left|t\right|<0.4\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ and becomes large and positive for larger $\mathrm{}\left|t\right|\mathrm{}$.