Near threshold photoproduction of eta mesons from He-4

Authors
Hejny, V Achenbach, P Ahrens, J Beck, R Hall, SJ Kotulla, M Krusche, B Kuhr, V Leukel, R Metag, V Novotny, R de Leon, VO Owens, RO Rambo, F Schmidt, A Schumacher, M Siodlaczek, U Stroher, H Wissmann, F Weiss, J Wolf, M
Citation
V. Hejny et al., Near threshold photoproduction of eta mesons from He-4, EUR PHY J A, 6(1), 1999, pp. 83-89
Citations number
23
Categorie Soggetti
Physics
Journal title
EUROPEAN PHYSICAL JOURNAL A
ISSN journal
14346001 → ACNP
Volume
6
Issue
1
Year of publication
1999
Pages
83 - 89
Database
ISI
SICI code
1434-6001(199909)6:1<83:NTPOEM>2.0.ZU;2-W
Abstract
Photoproduction of eta mesons from He-4 has been measured for the first tim e, The experiment was performed at the Mains Microtron (MAMI) using the TAP S photon spectrometer and the Glasgow/Mainz tagged photon facility, eta mes ons were identified in coincidence with recoil nucleons. Total and differen tial cross sections are presented in the photon energy range between thresh old and 818 MeV. The exclusive data are used to determine the ratio of the elementary production cross sections on bound neutrons and protons. sigma(n )/sigma(p) = 0.68 +/- 0.02 +/- 0.09. In addition, upper limits for the tota l coherent cross section have been derived.