Narrow structure in the excitation function of η photoproduction off the neutron

Werthmueller, D. et al. (2013) Narrow structure in the excitation function of η photoproduction off the neutron. Physical Review Letters, 111(23), Art. 232001. (doi: 10.1103/PhysRevLett.111.232001) (PMID:24476257)

90287.pdf - Accepted Version



The photoproduction of η mesons off nucleons bound in H2 and H3e has been measured in coincidence with recoil protons and recoil neutrons for incident photon energies from threshold up to 1.4 GeV. The experiments were performed at the Mainz MAMI accelerator, using the Glasgow tagged photon facility. Decay photons from the η→2γ and η→3π0 decays and the recoil nucleons were detected with an almost 4π electromagnetic calorimeter combining the Crystal Ball and TAPS detectors. The data from both targets are of excellent statistical quality and show a narrow structure in the excitation function of γn→nη. The results from the two measurements are consistent, taking into account the expected effects from nuclear Fermi motion. The best estimates for position and intrinsic width of the structure are W=(1670±5)  MeV and Γ=(30±15)  MeV. For the first time precise results for the angular dependence of this structure have been extracted.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Middleton, Dr Duncan and Glazier, Dr Derek and McGeorge, Dr John and Robinson, Mr Jamie and Downie, Dr Evangeline and MacGregor, Professor Douglas and Livingston, Dr Kenneth and McNicoll, Miss Eilidh and Annand, Dr John and Hamilton, Dr David and Rosner, Professor Guenther
Authors: Werthmueller, D., Witthauer, L., Keshelashvili, I., Aguar-Bartolome, P., Ahrens, J., Annand, J.R.M., Arends, H.J., Bantawa, K., Beck, R., Bekrenev, V., Braghieri, A., Branford, D., Briscoe, W.J., Brudvik, J., Cherepnya, S., Demissie, B., Dieterle, M., Downie, E.J., Drexler, P., Fil'kov, L.V., Fix, A., Glazier, D.I., Hamilton, D., Heid, E., Hornidge, D., Howdle, D., Huber, G.M., Jaegle, I., Jahn, O., Jude, T.C., Kaeser, A., Kashevarov, V.L., Kondratiev, R., Korolija, M., Kruglov, S.P., Krusche, B., Kulbardis, A., Lisin, V., Livingston, K., MacGregor, I.J.D., Maghrbi, Y., Mancell, J., Manley, D.M., Marinides, Z., Martinez, M., McGeorge, J.C., McNicoll, E.F., Metag, V., Middleton, D.G., Mushkarenkov, A., Nefkens, B.M.K., Nikolaev, A., Novotny, R., Oberle, M., Ostrick, M., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S.N., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M.H., Sober, D., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., Watts, D.P., and Collaboration, A.
Subjects:Q Science > QC Physics
College/School:College of Science and Engineering > School of Physics and Astronomy
Research Group:Nuclear Physics
Journal Name:Physical Review Letters
Journal Abbr.:Phys. Rev. Lett.
Publisher:American Physical Society
ISSN (Online):1079-7114
Copyright Holders:Copyright © 2014 American Physical Society
First Published:First published in Physical Review Letters 111(23):232001
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
570711Nuclear Physics GroupDavid IrelandScience & Technologies Facilities Council (STFC)ST/J000175/1P&A - PHYSICS & ASTRONOMY