Helicity dependence of the γ 3He → πX reactions in the Δ(1232) resonance region

Costanza, S. et al. (2014) Helicity dependence of the γ 3He → πX reactions in the Δ(1232) resonance region. European Physical Journal A, 50(173), -173:. (doi:10.1140/epja/i2014-14173-y)

Full text not currently available from Enlighten.

Abstract

The helicity dependences of the differential cross sections for the semi-inclusive γ 3He → π0 X and γ 3He → π± X reactions have been measured for the first time in the energy region 200 < E γ 450 MeV. The experiment was performed at the tagged photon beam facility of the MAMI accelerator in Mainz using a longitudinally polarised high-pressure 3He gas target. Hadronic products were measured with the large-acceptance Crystal Ball detector complemented with additional devices for charged-particle tracking and identification. Unpolarised differential cross sections and their helicity dependence are compared with theoretical calculations using the Fix-Arenhövel model. The effect of the intermediate excitation of the Δ(1232) resonance can be clearly seen from this comparison, especially for the polarised case, where nuclear effects are relatively small. The model provides a better theoretical description of the unpolarised charged pion photoproduction data than the neutral pion channel. It does significantly better in describing the helicity-dependent data in both channels. These comparisons provide new information on the mechanisms involved in pion photoproduction on 3He and suggest that a polarised 3He target can provide valuable information on the corresponding polarised quasi-free neutron reactions.

Item Type:Articles (Other)
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:McGeorge, Dr John and Middleton, Mr Duncan and Downie, Dr Evangeline and Livingston, Dr Kenneth and MacGregor, Professor Douglas and Howdle, Mr David and Annand, Dr John and Mancell, Mr Joe and Hamilton, Dr David and Glazier, Dr Derek and Rosner, Professor Guenther
Authors: Costanza, S., Mushkarenvov, A., Rigamonti, F., Aguar Bartolome, P., Ahrens, J., Annand, J.R.M., Arends, H.J., Beck, R., Braghieri, A., Bekrenev, V., Berghauser, H., Briscoe, W.J., Cherepnya, S.N., Collicott, C., Downie, E.J., Drexler, P., Fil'kov, L.V., Fix, A., Glazier, D.I., Hamilton, D., Heid, E., Heil, W., Hornidge, D., Howdle, D., Jaegle, I., Huber, G.M., Jahn, O., Jude, T., Kashevarov, V.L., Keshelashvili, I., Kondratiev, R., Korolija, M., Krimmer, J., Krusche, B., Kruglov, S., Kulbardis, A., Lisin, V., Livingston, K., MacGregor, I.J.D., Mancell, J., Mandaglio, G., Manley, D.M., McGeorge, J.C., Middleton, D.G., Metag, V., Nefkens, B.M.K., Nikolaev, A., Oberle, M., Ostrick, M., Ortega, H., Otte, P.B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Rosner, G., Rostomyan, T., Sarty, A.J., Schumann, S., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unversagt, M., Watts, D.P., and Werthmueller, D.
Subjects:Q Science > QC Physics
College/School:College of Science and Engineering > School of Physics and Astronomy
Research Group:Nuclear Physics
Journal Name:European Physical Journal A
Publisher:Springer Berlin Heidelberg
ISSN:1434-6001
ISSN (Online):1434-601X

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
577011High-Flux multi-spectral x-ray imaging with energy-sensitive CZT detectorsValentine O'SheaScience & Technologies Facilities Council (STFC)ST/I003134/1P&A - PHYSICS & ASTRONOMY
577012High-Flux multi-spectral x-ray imaging with energy-sensitive CZT detectorsValentine O'SheaInstitute of Cancer Research (EXTICR)UNSPECIFIEDP&A - PHYSICS & ASTRONOMY