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Kashevarov VL, Ott P, Prakhov S, Adlarson P, Afzal F, Ahmed Z, Akondi CS, Annand JRM, Arends HJ, Beck R, Braghieri A, Briscoe WJ, Cividini F, Codling R, Collicott C, Costanza S, Denig A, Downie EJ, Dieterle M, Ferretti Bondy MI, Fil'kov LV, Fix A, Gardner S, Garni S, Glazier DI, Glowa D, Gradl W, Gurevich G, Hamilton DJ, Hornidge D, Howdle D, Huber GM, Käser A, Kay S, Keshelashvili I, Kondratiev R, Korolija M, Krusche B, Linturi J, Lisin V, Livingston K, MacGregor IJD, MacRae R, Mancell J, Manley DM, Martel PP, McGeorge JC, McNicol E, Middleton DG, Miskimen R, Mornacchi E, Mullen C, Mushkarenkov A, Neiser A, Oberle M, Ostrick M, Otte PB, Oussena B, Paudyal D, Pedroni P, Polyanski VV, Rajabi A, Reicherz G, Robinson J, Rosner G, Rostomyan T, Sarty A, Schott DM, Schumann S, Sfienti C, Sokhoyan V, Spieker K, Steffen O, Strandberg B, Strakovsky II, Strub T, Supek I, Taragin MF, Thiel A, Thiel M, Tiator L, Thomas A, Unverzagt M, Wagner S, Watts DP, Werthmüller D, Wettig J, Witthauer L, Wolfes M, Workman RL, Zana L. Study of η and η' Photoproduction at MAMI. Phys Rev Lett 2017; 118:212001. [PMID: 28598665 DOI: 10.1103/physrevlett.118.212001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Indexed: 06/07/2023]
Abstract
The reactions γp→ηp and γp→η^{'}p are measured from their thresholds up to the center-of-mass energy W=1.96 GeV with the tagged-photon facilities at the Mainz Microtron, MAMI. Differential cross sections are obtained with unprecedented statistical accuracy, providing fine energy binning and full production-angle coverage. A strong cusp is observed in the total cross section for η photoproduction at the energies in the vicinity of the η^{'} threshold, W=1896 MeV (E_{γ}=1447 MeV). Within the framework of a revised ηMAID isobar model, the cusp, in connection with a steep rise of the η^{'} total cross section from its threshold, can only be explained by a strong coupling of the poorly known N(1895)1/2^{-} state to both ηp and η^{'}p. Including the new high-accuracy results in the ηMAID fit to available η and η^{'} photoproduction data allows the determination of the N(1895)1/2^{-} properties.
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Affiliation(s)
- V L Kashevarov
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - P Ott
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - S Prakhov
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- The George Washington University, Washington, D.C. 20052-0001, USA
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - P Adlarson
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - Z Ahmed
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - C S Akondi
- Kent State University, Kent, Ohio 44242-0001, USA
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | | | - W J Briscoe
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - F Cividini
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - R Codling
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - C Collicott
- Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
- Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Italy
- Dipartimento di Fisica, Università di Pavia, I-27100 Pavia, Italy
| | - A Denig
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - E J Downie
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - M Dieterle
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M I Ferretti Bondy
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - L V Fil'kov
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634034 Tomsk, Russia
| | - S Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - S Garni
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Glowa
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W Gradl
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - G Gurevich
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - D J Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - A Käser
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - S Kay
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - I Keshelashvili
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - J Linturi
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - V Lisin
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - R MacRae
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Mancell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242-0001, USA
| | - P P Martel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - J C McGeorge
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E McNicol
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D G Middleton
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - R Miskimen
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - E Mornacchi
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - C Mullen
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - A Mushkarenkov
- INFN Sezione di Pavia, I-27100 Pavia, Italy
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - A Neiser
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Oberle
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - D Paudyal
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | | | - A Rajabi
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - J Robinson
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G Rosner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - T Rostomyan
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - A Sarty
- Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
| | - D M Schott
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - S Schumann
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - C Sfienti
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - V Sokhoyan
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - O Steffen
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - B Strandberg
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I I Strakovsky
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - Th Strub
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - M F Taragin
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - M Thiel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - L Tiator
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - S Wagner
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - D P Watts
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Werthmüller
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - J Wettig
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - L Witthauer
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M Wolfes
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - R L Workman
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - L Zana
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
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2
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Martel PP, Miskimen R, Aguar-Bartolome P, Ahrens J, Akondi CS, Annand JRM, Arends HJ, Barnes W, Beck R, Bernstein A, Borisov N, Braghieri A, Briscoe WJ, Cherepnya S, Collicott C, Costanza S, Denig A, Dieterle M, Downie EJ, Fil'kov LV, Garni S, Glazier DI, Gradl W, Gurevich G, Hall Barrientos P, Hamilton D, Hornidge D, Howdle D, Huber GM, Jude TC, Kaeser A, Kashevarov VL, Keshelashvili I, Kondratiev R, Korolija M, Krusche B, Lazarev A, Lisin V, Livingston K, MacGregor IJD, Mancell J, Manley DM, Meyer W, Middleton DG, Mushkarenkov A, Nefkens BMK, Neganov A, Nikolaev A, Oberle M, Ortega Spina H, Ostrick M, Ott P, Otte PB, Oussena B, Pedroni P, Polonski A, Polyansky V, Prakhov S, Rajabi A, Reicherz G, Rostomyan T, Sarty A, Schrauf S, Schumann S, Sikora MH, Starostin A, Steffen O, Strakovsky II, Strub T, Supek I, Thiel M, Tiator L, Thomas A, Unverzagt M, Usov Y, Watts DP, Witthauer L, Werthmüller D, Wolfes M. Measurements of double-polarized compton scattering asymmetries and extraction of the proton spin polarizabilities. Phys Rev Lett 2015; 114:112501. [PMID: 25839263 DOI: 10.1103/physrevlett.114.112501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Indexed: 06/04/2023]
Abstract
The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to extract the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the Δ(1232) region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron. Fits to asymmetry data were performed using a dispersion model calculation and a baryon chiral perturbation theory calculation, and a separation of all four proton spin polarizabilities in the multipole basis was achieved. The analysis based on a dispersion model calculation yields γ(E1E1)=-3.5±1.2, γ(M1M1)=3.16±0.85, γ(E1M2)=-0.7±1.2, and γ(M1E2)=1.99±0.29, in units of 10(-4) fm(4).
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Affiliation(s)
- P P Martel
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- Department of Physics, Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - R Miskimen
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | | | - J Ahrens
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - C S Akondi
- Department of Physics, Kent State University, Kent, Ohio 44242, USA
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - W Barnes
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - A Bernstein
- Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - N Borisov
- Joint Institute for Nuclear Research (JINR), 141980 Dubna, Russia
| | | | - W J Briscoe
- Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - S Cherepnya
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - C Collicott
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Denig
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - M Dieterle
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - E J Downie
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - L V Fil'kov
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - S Garni
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W Gradl
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - G Gurevich
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - P Hall Barrientos
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Hornidge
- Department of Physics, Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G M Huber
- Department of Physics, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - T C Jude
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - A Kaeser
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | | | - I Keshelashvili
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - A Lazarev
- Joint Institute for Nuclear Research (JINR), 141980 Dubna, Russia
| | - V Lisin
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Mancell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Department of Physics, Kent State University, Kent, Ohio 44242, USA
| | - W Meyer
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - D G Middleton
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- Department of Physics, Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - A Mushkarenkov
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - B M K Nefkens
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - A Neganov
- Joint Institute for Nuclear Research (JINR), 141980 Dubna, Russia
| | - A Nikolaev
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - M Oberle
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - H Ortega Spina
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - M Ostrick
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - P Ott
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Polonski
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - V Polyansky
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - S Prakhov
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- Department of Physics, The George Washington University, Washington, D.C. 20052, USA
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - A Rajabi
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - T Rostomyan
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - A Sarty
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Schrauf
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - S Schumann
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - M H Sikora
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - A Starostin
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - O Steffen
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - I I Strakovsky
- Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - T Strub
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - M Thiel
- II. Physikalisches Institut, Universität Giessen, D-35392 Giessen, Germany
| | - L Tiator
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - Y Usov
- Joint Institute for Nuclear Research (JINR), 141980 Dubna, Russia
| | - D P Watts
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - L Witthauer
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - D Werthmüller
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M Wolfes
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
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3
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Akondi CS, Annand JRM, Arends HJ, Beck R, Bernstein A, Borisov N, Braghieri A, Briscoe WJ, Cherepnya S, Collicott C, Costanza S, Downie EJ, Dieterle M, Fix A, Fil'kov LV, Garni S, Glazier DI, Gradl W, Gurevich G, Hall Barrientos P, Hamilton D, Hornidge D, Howdle D, Huber GM, Kashevarov VL, Keshelashvili I, Kondratiev R, Korolija M, Krusche B, Lazarev A, Lisin V, Livingston K, MacGregor IJD, Mancel J, Manley DM, Martel P, McNicoll EF, Meyer W, Middleton D, Miskimen R, Mushkarenkov A, Nefkens BMK, Neganov A, Nikolaev A, Oberle M, Ostrick M, Ortega H, Ott P, Otte PB, Oussena B, Pedroni P, Polonski A, Polyanski VV, Prakhov S, Reicherz G, Rostomyan T, Sarty A, Schumann S, Steffen O, Strakovsky II, Strub T, Supek I, Tiator L, Thomas A, Unverzagt M, Usov YA, Watts DP, Werthmüller D, Witthauer L, Wolfes M. Measurement of the transverse target and beam-target asymmetries in η meson photoproduction at MAMI. Phys Rev Lett 2014; 113:102001. [PMID: 25238349 DOI: 10.1103/physrevlett.113.102001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Indexed: 06/03/2023]
Abstract
We present new data for the transverse target asymmetry T and the very first data for the beam-target asymmetry F in the γ[over →]p[over →]→ηp reaction up to a center-of-mass energy of W=1.9 GeV. The data were obtained with the Crystal-Ball/TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. All existing model predictions fail to reproduce the new data indicating a significant impact on our understanding of the underlying dynamics of η meson photoproduction. The peculiar nodal structure observed in existing T data close to threshold is not confirmed.
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Affiliation(s)
- C S Akondi
- Kent State University, Kent, Ohio 44242-0001, USA
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - A Bernstein
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - N Borisov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | | | - W J Briscoe
- The George Washington University, Washington, DC 20052-0001, USA
| | - S Cherepnya
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - C Collicott
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - E J Downie
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and The George Washington University, Washington, DC 20052-0001, USA
| | - M Dieterle
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634034 Tomsk, Russia
| | - L V Fil'kov
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - S Garni
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom and SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W Gradl
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - G Gurevich
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - P Hall Barrientos
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - V L Kashevarov
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and Lebedev Physical Institute, 119991 Moscow, Russia
| | - I Keshelashvili
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - A Lazarev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - V Lisin
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Mancel
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242-0001, USA
| | - P Martel
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA and University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - E F McNicoll
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - W Meyer
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - D Middleton
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - R Miskimen
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - A Mushkarenkov
- INFN Sezione di Pavia, I-27100 Pavia, Italy and University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - B M K Nefkens
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - A Neganov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Nikolaev
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - M Oberle
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - H Ortega
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - P Ott
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and The George Washington University, Washington, DC 20052-0001, USA
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Polonski
- Institute for Nuclear Research, 125047 Moscow, Russia
| | | | - S Prakhov
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - T Rostomyan
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - A Sarty
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Schumann
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - O Steffen
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - I I Strakovsky
- The George Washington University, Washington, DC 20052-0001, USA
| | - Th Strub
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - L Tiator
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - Yu A Usov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - D P Watts
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Werthmüller
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - L Witthauer
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - M Wolfes
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
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4
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Dieterle M, Keshelashvili I, Ahrens J, Annand JRM, Arends HJ, Bantawa K, Bartolome PA, Beck R, Bekrenev V, Braghieri A, Branford D, Briscoe WJ, Brudvik J, Cherepnya S, Demissie B, Downie EJ, Drexler P, Fil'kov LV, Fix A, Glazier DI, Hamilton D, Heid E, Hornidge D, Howdle D, Huber GM, Jaegle I, Jahn O, Jude TC, Käser A, Kashevarov VL, Kondratiev R, Korolija M, Kruglov SP, Krusche B, Kulbardis A, Lisin V, Livingston K, MacGregor IJD, Maghrbi Y, Mancell J, Manley DM, Marinides Z, Martinez M, McGeorge JC, McNicoll E, Mekterovic D, Metag V, Micanovic S, Middleton DG, Mushkarenkov A, Nefkens BMK, Nikolaev A, Novotny R, Oberle M, Ostrick M, Oussena B, Pedroni P, Pheron F, Polonski A, Prakhov SN, Robinson J, Rosner G, Rostomyan T, Schumann S, Sikora MH, Sober D, Starostin A, Supek I, Thiel M, Thomas A, Unverzagt M, Watts DP, Werthmüller D, Witthauer L. Photoproduction of π0 mesons off neutrons in the nucleon resonance region. Phys Rev Lett 2014; 112:142001. [PMID: 24765945 DOI: 10.1103/physrevlett.112.142001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Indexed: 06/03/2023]
Abstract
Precise angular distributions have been measured for the first time for the photoproduction of π0 mesons off neutrons bound in the deuteron. The effects from nuclear Fermi motion have been eliminated by a complete kinematic reconstruction of the final state. The influence of final-state-interaction effects has been estimated by a comparison of the reaction cross section for quasifree protons bound in the deuteron to the results for free protons and then applied as a correction to the quasifree neutron data. The experiment was performed at the tagged photon facility of the Mainz Microtron MAMI with the Crystal Ball and TAPS detector setup for incident photon energies between 0.45 and 1.4 GeV. The results are compared to the predictions from reaction models and partial-wave analyses based on data from other isospin channels. The model predictions show large discrepancies among each other and the present data will provide much tighter constraints. This is demonstrated by the results of a new analysis in the framework of the Bonn-Gatchina coupled-channel analysis which included the present data.
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Affiliation(s)
- M Dieterle
- Department of Physics, University of Basel, Switzerland
| | | | - J Ahrens
- Institut für Kernphysik, University of Mainz, Germany
| | - J R M Annand
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - H J Arends
- Institut für Kernphysik, University of Mainz, Germany
| | - K Bantawa
- Kent State University, Kent, Ohio, USA
| | - P A Bartolome
- Institut für Kernphysik, University of Mainz, Germany
| | - R Beck
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Germany
| | - V Bekrenev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | | | - D Branford
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - W J Briscoe
- Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | - J Brudvik
- University of California at Los Angeles, Los Angeles, California, USA
| | | | - B Demissie
- Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | - E J Downie
- Institut für Kernphysik, University of Mainz, Germany and Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom and Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | - P Drexler
- II. Physikalisches Institut, University of Giessen, Germany
| | | | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, Tomsk, Russia
| | - D I Glazier
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - D Hamilton
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - E Heid
- Institut für Kernphysik, University of Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S 0A2 Canada
| | - I Jaegle
- Department of Physics, University of Basel, Switzerland
| | - O Jahn
- Institut für Kernphysik, University of Mainz, Germany
| | - T C Jude
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - A Käser
- Department of Physics, University of Basel, Switzerland
| | - V L Kashevarov
- Institut für Kernphysik, University of Mainz, Germany and Lebedev Physical Institute, Moscow, Russia
| | | | - M Korolija
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - S P Kruglov
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - B Krusche
- Department of Physics, University of Basel, Switzerland
| | - A Kulbardis
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - V Lisin
- Institute for Nuclear Research, Moscow, Russia
| | - K Livingston
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - I J D MacGregor
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - Y Maghrbi
- Department of Physics, University of Basel, Switzerland
| | - J Mancell
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | | | - Z Marinides
- Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | - M Martinez
- Institut für Kernphysik, University of Mainz, Germany
| | - J C McGeorge
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - E McNicoll
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | | | - V Metag
- II. Physikalisches Institut, University of Giessen, Germany
| | | | - D G Middleton
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | | | - B M K Nefkens
- University of California at Los Angeles, Los Angeles, California, USA
| | - A Nikolaev
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Germany
| | - R Novotny
- II. Physikalisches Institut, University of Giessen, Germany
| | - M Oberle
- Department of Physics, University of Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, University of Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, University of Mainz, Germany and Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | | | - F Pheron
- Department of Physics, University of Basel, Switzerland
| | - A Polonski
- Institute for Nuclear Research, Moscow, Russia
| | - S N Prakhov
- University of California at Los Angeles, Los Angeles, California, USA
| | - J Robinson
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - G Rosner
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - T Rostomyan
- Department of Physics, University of Basel, Switzerland
| | - S Schumann
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Germany
| | - M H Sikora
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - D Sober
- The Catholic University of America, Washington, DC, USA
| | - A Starostin
- University of California at Los Angeles, Los Angeles, California, USA
| | - I Supek
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - M Thiel
- Institut für Kernphysik, University of Mainz, Germany and II. Physikalisches Institut, University of Giessen, Germany
| | - A Thomas
- Institut für Kernphysik, University of Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Germany
| | - D P Watts
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - D Werthmüller
- Department of Physics, University of Basel, Switzerland
| | - L Witthauer
- Department of Physics, University of Basel, Switzerland
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5
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Werthmüller D, Witthauer L, Keshelashvili I, Aguar-Bartolomé P, Ahrens J, Annand JRM, Arends HJ, Bantawa K, Beck R, Bekrenev V, Braghieri A, Branford D, Briscoe WJ, Brudvik J, Cherepnya S, Demissie B, Dieterle M, Downie EJ, Drexler P, Fil'kov LV, Fix A, Glazier DI, Hamilton D, Heid E, Hornidge D, Howdle D, Huber GM, Jaegle I, Jahn O, Jude TC, Käser A, Kashevarov VL, Kondratiev R, Korolija M, Kruglov SP, Krusche B, Kulbardis A, Lisin V, Livingston K, MacGregor IJD, Maghrbi Y, Mancell J, Manley DM, Marinides Z, Martinez M, McGeorge JC, McNicoll EF, Metag V, Middleton DG, Mushkarenkov A, Nefkens BMK, Nikolaev A, Novotny R, Oberle M, Ostrick M, Oussena B, Pedroni P, Pheron F, Polonski A, Prakhov SN, Robinson J, Rosner G, Rostomyan T, Schumann S, Sikora MH, Sober D, Starostin A, Supek I, Thiel M, Thomas A, Unverzagt M, Watts DP. Narrow structure in the excitation function of η photoproduction off the neutron. Phys Rev Lett 2013; 111:232001. [PMID: 24476257 DOI: 10.1103/physrevlett.111.232001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 10/28/2013] [Indexed: 06/03/2023]
Abstract
The photoproduction of η mesons off nucleons bound in 2H and 3He 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.
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Affiliation(s)
- D Werthmüller
- Departement für Physik, Universität Basel, Switzerland
| | - L Witthauer
- Departement für Physik, Universität Basel, Switzerland
| | | | | | - J Ahrens
- Institut für Kernphysik, Universität Mainz, Germany
| | - J R M Annand
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Universität Mainz, Germany
| | - K Bantawa
- Kent State University, Kent, Ohio, USA
| | - R Beck
- Institut für Kernphysik, Universität Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - V Bekrenev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | | | - D Branford
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W J Briscoe
- Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | - J Brudvik
- University of California at Los Angeles, Los Angeles, California, USA
| | | | - B Demissie
- Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | - M Dieterle
- Departement für Physik, Universität Basel, Switzerland
| | - E J Downie
- Institut für Kernphysik, Universität Mainz, Germany and SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom and Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | - P Drexler
- II. Physikalisches Institut, Universität Giessen, Germany
| | | | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, Tomsk, Russia
| | - D I Glazier
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Hamilton
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E Heid
- Institut für Kernphysik, Universität Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G M Huber
- University of Regina, Regina, SK S4S 0A2, Canada
| | - I Jaegle
- Departement für Physik, Universität Basel, Switzerland
| | - O Jahn
- Institut für Kernphysik, Universität Mainz, Germany
| | - T C Jude
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - A Käser
- Departement für Physik, Universität Basel, Switzerland
| | - V L Kashevarov
- Institut für Kernphysik, Universität Mainz, Germany and Lebedev Physical Institute, Moscow, Russia
| | | | - M Korolija
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - S P Kruglov
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - B Krusche
- Departement für Physik, Universität Basel, Switzerland
| | - A Kulbardis
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - V Lisin
- Institute for Nuclear Research, Moscow, Russia
| | - K Livingston
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Y Maghrbi
- Departement für Physik, Universität Basel, Switzerland
| | - J Mancell
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | - Z Marinides
- Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | - M Martinez
- Institut für Kernphysik, Universität Mainz, Germany
| | - J C McGeorge
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E F McNicoll
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - V Metag
- II. Physikalisches Institut, Universität Giessen, Germany
| | - D G Middleton
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | | | - B M K Nefkens
- University of California at Los Angeles, Los Angeles, California, USA
| | - A Nikolaev
- Institut für Kernphysik, Universität Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - R Novotny
- II. Physikalisches Institut, Universität Giessen, Germany
| | - M Oberle
- Departement für Physik, Universität Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, Universität Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, Universität Mainz, Germany and Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | | | - F Pheron
- Departement für Physik, Universität Basel, Switzerland
| | - A Polonski
- Institute for Nuclear Research, Moscow, Russia
| | - S N Prakhov
- Institut für Kernphysik, Universität Mainz, Germany and Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA and University of California at Los Angeles, Los Angeles, California, USA
| | - J Robinson
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G Rosner
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - T Rostomyan
- Departement für Physik, Universität Basel, Switzerland
| | - S Schumann
- Institut für Kernphysik, Universität Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - M H Sikora
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Sober
- The Catholic University of America, Washington, District of Columbia, USA
| | - A Starostin
- University of California at Los Angeles, Los Angeles, California, USA
| | - I Supek
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - M Thiel
- Institut für Kernphysik, Universität Mainz, Germany and II. Physikalisches Institut, Universität Giessen, Germany
| | - A Thomas
- Institut für Kernphysik, Universität Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, Universität Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - D P Watts
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
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