# Photoproduction of η′-mesons off the deuteron

Jaegle, I. and Mertens, T. and Fix, A. and Huang, F. and Nakayama, K. and Tiator, L. and Anisovich, A. V. and Bacelar, J. C. S. and Bantes, B. and Bartholomy, O. and Bayadilov, D. E. and Beck, R. and Beloglazov, Y. A. and Castelijns, R. and Crede, V. and Dutz, H. and Elsner, D. and Ewald, R. and Frommberger, F. and Funke, C. and Gregor, R. and Gridnev, A. B. and Gutz, E. and Hillert, W. and Hoeffgen, S. and Junkersfeld, J. and Kalinowsky, H. and Kammer, S. and Kleber, V. and Klein, Frank and Klein, Friedrich and Klempt, E. and Kotulla, M. and Krusche, B. and Lang, M. and Loehner, H. and Lopatin, I. V. and Lugert, S. and Menze, D. and Messchendorp, J. G. and Metag, V. and Nikonov, V. A. and Nanova, M. and Novinski, D. V. and Novotny, R. and Ostrick, M. and Pant, L. M. and van Pee, H. and Pfeiffer, M. and Roy, A. and Sarantsev, A. V. and Schadmand, S. and Schmidt, C. and Schmieden, H. and Schoch, B. and Shende, S. V. and Sokhoyan, V. and Suele, A. and Sumachev, V. V. and Szczepanek, T. and Thoma, U. and Trnka, D. and Varma, R. and Walther, D. and Wendel, C.. (2011) Photoproduction of η′-mesons off the deuteron. European Physical Journal A: Hadrons and Nuclei, 47 (1). p. 11.

Full text not available from this repository.

Official URL: http://edoc.unibas.ch/47295/

Quasi-free photoproduction of eta-mesons off nucleons bound in the deuteron has been measured with the combined Crystal Barrel - TAPS detector. The experiment was done at a tagged photon beam of the ELSA electron accelerator in Bonn for incident photon energies from the production threshold up to 2.5 GeV. The eta-mesons have been detected in coincidence with recoil protons and recoil neutrons. The quasi-free proton data are in good agreement with the results for free protons, indicating that nuclear effects have no significant impact. The coincidence with recoil neutrons provides the first data for the gamma n -&gt; n eta reaction. In addition, also first estimates for coherent eta-production off the deuteron have been obtained. In agreement with model predictions, the total cross-section for this channel is found to be very small, at most at the level of a few nb. The data are compared to model calculations taking into account contributions from nucleon resonances and t-channel exchanges.