Measurement of polarisation observables in $K_s^0\hat{I}{\pounds }^{+}$ photoproduction off the proton

Abstract

The reaction ${\hat{I}}^{3}p\to K_S^0\hat{I}{\pounds }^{+}$ is studied in the photon energy range from threshold. Linearly polarised photon beams from coherent bremsstrahlung enabled the first measurement of photon beam asymmetries in this reaction up to $E_{\hat{I}}^3=2250$ MeV. In addition, the recoil hyperon polarisation was determined through the asymmetry in the weak decay $\hat{I}{\pounds }^{+}\to p\ddot{I}{€}^0$ up to $E_{\hat{I}}^3=1650$ MeV. The data are compared to partial wave analyses, and the possible impact on the interpretation of a recently observed cusp-like structure near the $K^{\ast }$ thresholds is discussed.

6 pages, 5 figures. References [8,9,10,11] which were not on the original submission are now included