Measurement of the Helicity Asymmetry $E$ for the reaction ${\hat{I}}^{3}p\to \ddot{I}{€}^{0}p$

Abstract

A measurement of the double-polarization observable $E$ for the reaction ${\hat{I}}^{3}p\to \ddot{I}{€}^{0}p$ is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C${}_4$H${}_9$OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from $E_{\hat{I}}^3=600$~MeV to $E_{\hat{I}}^3=2310$~MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

21 pages