Near Threshold Photoproduction of <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="italic">η</mi></math></span> Mesons off the Proton

B. Krusche; J. Ahrens; G. Anton; R. Beck; M. Fuchs; A. R. Gabler; F. Härter; S. Hall; P. Harty; S. Hlavac; D. MacGregor; C. McGeorge; V. Metag; R. Owens; J. Peise; M. Röbig-Landau; A. Schubert; R. S. Simon; H. Ströher; V. Tries

doi:10.1103/PhysRevLett.74.3736

Near Threshold Photoproduction of $η$ Mesons off the Proton

B. Krusche, J. Ahrens, G. Anton, R. Beck, M. Fuchs, A. R. Gabler, F. Härter, S. Hall, P. Harty, S. Hlavac, D. MacGregor, C. McGeorge, V. Metag, R. Owens, J. Peise, M. Röbig-Landau, A. Schubert, R. S. Simon, H. Ströher, and V. Tries

Phys. Rev. Lett. 74, 3736 – Published 8 May 1995

Abstract

We have measured precise total and differential cross sections for the reaction $γ p \to p η$ from threshold to 790 MeV at the MAMI accelerator in Mainz with the neutral meson spectrometer TAPS. Resonance parameters of the $S_{11}$ (1535) resonance and the electromagnetic coupling $γ p \to S_{11}$ have been extracted from the data. Contributions from the $D_{13}$ (1520) resonance to $η$ photoproduction in the threshold region have been identified for the first time via interference terms in the angular distributions.

Received 1 December 1994

DOI:https://doi.org/10.1103/PhysRevLett.74.3736

Authors & Affiliations

B. Krusche¹, J. Ahrens², G. Anton⁴, R. Beck², M. Fuchs¹, A. R. Gabler¹, F. Härter², S. Hall³, P. Harty³, S. Hlavac⁵, D. MacGregor³, C. McGeorge³, V. Metag¹, R. Owens³, J. Peise², M. Röbig-Landau¹, A. Schubert⁵, R. S. Simon⁵, H. Ströher¹, and V. Tries¹

¹II. Physikalisches Institut, Universität Giessen, D-35392 Giessen, Germany
²Institut für Kernphysik, Johannes-Gutenberg-Universität Mainz, D-55099 Mainz, Germany
³Kelvin Laboratory, University of Glasgow, United Kingdom
⁴Physikalisches Institut, Universität Bonn, D-53115 Bonn, Germany
⁵Gesellschaft für Schwerionenforschung, D-64220 Darmstadt, Germany