Photoproduction of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>η</mml:mi></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi>η</mml:mi><mml:mrow><mml:mo>'</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>mesons off protons

Abstract

Total and differential cross sections for $\ensuremath{\eta}$ and ${\ensuremath{\eta}}^{'}$photoproduction off the proton have been determined with the CBELSA/TAPS detector for photon energies between $0.85$ and $2.55$ GeV. The $\ensuremath{\eta}$ mesons are detected in their two neutral decay modes, $\ensuremath{\eta}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$ and $\ensuremath{\eta}\ensuremath{\rightarrow}3{\ensuremath{\pi}}^{0}\ensuremath{\rightarrow}6\ensuremath{\gamma}$, and for the first time, cover the full angular range in $\mathrm{cos} {\ensuremath{\theta}}_{c.m.}$ of the $\ensuremath{\eta}$ meson. These new $\ensuremath{\eta}$ photoproduction data are consistent with the earlier CB-ELSA results. The ${\ensuremath{\eta}}^{'}$ mesons are observed in their neutral decay to ${\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}\ensuremath{\eta}\ensuremath{\rightarrow}6\ensuremath{\gamma}$ and also extend the coverage in angular range.