Beam-helicity asymmetries in double-pion photoproduction off the proton

Krambrich, D. et al. (2009) Beam-helicity asymmetries in double-pion photoproduction off the proton. Physical Review Letters, 103(5), 052002. (doi: 10.1103/PhysRevLett.103.052002)

Abstract

Beam-helicity asymmetries have been measured at the MAMI accelerator in Mainz in the three isospin channels γ⃗ p→π⁺π⁰n, γ⃗ p→π⁰π⁰p, and γ⃗ p→π⁺π⁻p. The circularly polarized photons, produced from bremsstrahlung of longitudinally polarized electrons, were tagged with the Glasgow magnetic spectrometer. Charged pions and the decay photons of π0 mesons were detected in a 4π electromagnetic calorimeter which combined the Crystal Ball detector with the TAPS detector. The precisely measured asymmetries are very sensitive to details of the production processes and are thus key observables in the modeling of the reaction dynamics.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Glazier, Dr Derek and McGeorge, Dr John and Downie, Dr Evangeline and MacGregor, Professor Douglas and Livingston, Dr Kenneth and Annand, Dr John and Rosner, Professor Guenther
• Authors: Krambrich, D., Zehr, F., Fix, A., Roca, L., Aguar, P., Ahrens, J., Annand, J.R.M., Arends, H.J., Beck, R., Bekrenev, V., Boillat, B., Braghieri, A., Branford, D., Briscoe, W.J., Brudvik, J., Cherepnya, S., Codling, R., Downie, E.J., Dexler, P., Glazier, D.I., Grabmayr, P., Gregor, R., Heid, E., Hornidge, D., Jahn, O., Kashevarov, V.L., Knezevic, A., Kondratiev, R., Korolija, M., Kotulla, M., Krusche, B., Kulbardis, A., Lang, M., Lisin, V., Livingston, K., Lugert, S., MacGregor, I.J.D., Manley, D.M., Martinez, M., McGeorge, J.C., Mekterovic, D., Metag, V., Nefkens, B.M.K., Nikolaev, A., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S.N., Price, J.W., Rosner, G., Rost, M., Rostomyan, T., Schumann, S., Sober, D., Starostin, A., Supek, I., Tarbert, C.M., Thomas, A., Unverzagt, M., Walcher, T., and Watts, D.P.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review Letters
• Publisher: American Physical Society
• ISSN: 0031-9007
• ISSN (Online): 1079-7114