Search for Baryon-Exchange Production of Strange Exotic Mesons

Results are presented of a search for strange, doubly charged, narrow [full width at half maximum ≤0.2 ${(\mathrm{G}\mathrm{e}\mathrm{V}/{\mathit{c}}^2)}^2$] meson states produced in the baryon-exchange reaction ${\pi }^{+}p\to {{\Lambda }_f}^0{S}^{++}$ at 9.8 GeV/c. No evidence is found for such states. The 95%-confidence-level limit for the production cross section is < 20 nb for $M\left(S^{++}\right)<~2$ GeV/${\mathit{c}}^2$. Limits on $\sigma B$ from a kinematic reconstruction of final states with $S^{++}\to K^{+}{\pi }^{+}$ are ≤ 10 nb for $M\left(K^{+}{\pi }^{+}\right)<~2.0$ GeV/${\mathit{c}}^2$.