Cascade production in the reactions gamma p --> K+ K+ (X) and gamma p --> K^+ K^+ pi- (X)

Abstract

Photoproduction of the cascade resonances has been investigated in the reactions ${\hat{I}}^{3}p\to K^{+}{K}^{+}(X)$ and ${\hat{I}}^{3}p\to K^{+}{K}^{+}\ddot{I}{€}^{-}(X)$. The mass split of the $\hat{I}ž$ doublet is measured to be $5.4\pm 1.8$ MeV/c${}^2$, consistent with existing measurements. The differential (total) cross sections for the $\hat{I}{ž}^{-}$ have been determined for photon beam energies from 2.75 to 3.85 (4.75) GeV, and are consistent with a possible production mechanism of $Y^{\ast }\to K^{+}\hat{I}{ž}^{-}$ through a $t$-channel process. The reaction ${\hat{I}}^{3}p\to K^{+}{K}^{+}\ddot{I}{€}^{-}[\hat{I}{ž}^0]$ has also been investigated in search of excited cascade resonances. No significant signal of excited cascade states other than the $\hat{I}{ž}^{-}(1530)$ is observed. The cross section results of the $\hat{I}{ž}^{-}(1530)$ have also been obtained for photon beam energies from 3.35 to 4.75 GeV.

10 pages, 10 figures