Measurement of polarisation observables in $K^0_s\Sigma^+$   photoproduction off the proton
  The reaction $\gamma \, p \rightarrow K^0_S\,\Sigma^+$ 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 $E_\gamma = 2250$ MeV. In addition, the recoil hyperon polarisation was determined through the asymmetry in the weak decay $\Sigma^+ \rightarrow p \pi^0$ up to $E_\gamma = 1650$ 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 $K^*$ thresholds is discussed. 
R. Ewald, A.V. Anisovich, B. Bantes, O. Bartholomy, D. Bayadilov, R.   Beck, Y.A. Beloglazov, K.-T. Brinkmann, V. Crede, H. ...
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