1
|
Afzal F, Spieker K, Hurck P, Abt S, Achenbach P, Adlarson P, Ahmed Z, Akondi CS, Annand JRM, Arends HJ, Bashkanov M, Beck R, Biroth M, Borisov N, Braghieri A, Briscoe WJ, Cividini F, Collicott C, Costanza S, Denig A, Dieterle M, Downie EJ, Drexler P, Fegan S, Gardner S, Ghosal D, Glazier DI, Gorodnov I, Gradl W, Gurevich D, Heijkenskjöld L, Hornidge D, Huber GM, Kashevarov VL, Kay SJD, Korolija M, Krusche B, Lazarev A, Livingston K, Lutterer S, MacGregor IJD, Macrae RG, Manley DM, Martel PP, Miskimen R, Mocanu M, Mornacchi E, Mullen C, Neganov A, Neiser A, Oberle M, Ostrick M, Otte PB, Paudyal D, Pedroni P, Powell A, Reicherz G, Rostomyan T, Sfienti C, Sokhoyan V, Steffen O, Strakovsky II, Strub T, Supek I, Thiel A, Thiel M, Thomas A, Usov YA, Wagner S, Walford NK, Watts DP, Werthmüller D, Wettig J, Witthauer L, Wolfes M, Zachariou N. First Measurement Using Elliptically Polarized Photons of the Double-Polarization Observable E for γp→pπ^{0} and γp→nπ^{+}. PHYSICAL REVIEW LETTERS 2024; 132:121902. [PMID: 38579200 DOI: 10.1103/physrevlett.132.121902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 04/07/2024]
Abstract
We report the measurement of the helicity asymmetry E for the pπ^{0} and nπ^{+} final states using, for the first time, an elliptically polarized photon beam in combination with a longitudinally polarized target at the Crystal Ball experiment at MAMI. The results agree very well with data that were taken with a circularly polarized photon beam, showing that it is possible to simultaneously measure polarization observables that require linearly (e.g., G) and circularly polarized photons (e.g., E) and a longitudinally polarized target. The new data cover a photon energy range 270-1400 MeV for the pπ^{0} final state (230-842 MeV for the nπ^{+} final state) and the full range of pion polar angles, θ, providing the most precise measurement of the observable E. A moment analysis gives a clear observation of the pη cusp in the pπ^{0} final state.
Collapse
Affiliation(s)
- F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - P Hurck
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - S Abt
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - P Achenbach
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - P Adlarson
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - Z Ahmed
- University of Regina, Regina, SK S4S0A2, Canada
| | - C S Akondi
- 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, University of Mainz, D-55099 Mainz, Germany
| | - M Bashkanov
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - M Biroth
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N Borisov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Braghieri
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
| | - W J Briscoe
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - F Cividini
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - C Collicott
- Department of Astronomy and Physics, Saint Mary's University, E4L1E6 Halifax, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
- Dipartimento di Fisica, Università di Pavia, I-27100 Pavia, Italy
| | - A Denig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Dieterle
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - E J Downie
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - P Drexler
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - S Fegan
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - S Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - D Ghosal
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - I Gorodnov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - W Gradl
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Gurevich
- Institute for Nuclear Research, RU-125047 Moscow, Russia
| | - L Heijkenskjöld
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L1E6, Canada
| | - G M Huber
- University of Regina, Regina, SK S4S0A2, Canada
| | - V L Kashevarov
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S J D Kay
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - A Lazarev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - S Lutterer
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - R G Macrae
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242, USA
| | - P P Martel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- Mount Allison University, Sackville, New Brunswick E4L1E6, Canada
| | - R Miskimen
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - M Mocanu
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - E Mornacchi
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - C Mullen
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - A Neganov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Neiser
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Oberle
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Paudyal
- University of Regina, Regina, SK S4S0A2, Canada
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
| | - A Powell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr Universität, 44780 Bochum, Germany
| | - T Rostomyan
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - C Sfienti
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - V Sokhoyan
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - O Steffen
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - I I Strakovsky
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - T Strub
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - M Thiel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - Yu A Usov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S Wagner
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N K Walford
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - D P Watts
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - D Werthmüller
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - J Wettig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - L Witthauer
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - M Wolfes
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N Zachariou
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| |
Collapse
|
2
|
Bernauer JC, Schmidt A, Henderson BS, Ice LD, Khaneft D, O'Connor C, Russell R, Akopov N, Alarcon R, Ates O, Avetisyan A, Beck R, Belostotski S, Bessuille J, Brinker F, Calarco JR, Carassiti V, Cisbani E, Ciullo G, Contalbrigo M, De Leo R, Diefenbach J, Donnelly TW, Dow K, Elbakian G, Eversheim PD, Frullani S, Funke C, Gavrilov G, Gläser B, Görrissen N, Hasell DK, Hauschildt J, Hoffmeister P, Holler Y, Ihloff E, Izotov A, Kaiser R, Karyan G, Kelsey J, Kiselev A, Klassen P, Krivshich A, Kohl M, Lehmann I, Lenisa P, Lenz D, Lumsden S, Ma Y, Maas F, Marukyan H, Miklukho O, Milner RG, Movsisyan A, Murray M, Naryshkin Y, Perez Benito R, Perrino R, Redwine RP, Rodríguez Piñeiro D, Rosner G, Schneekloth U, Seitz B, Statera M, Thiel A, Vardanyan H, Veretennikov D, Vidal C, Winnebeck A, Yeganov V. Measurement of the Charge-Averaged Elastic Lepton-Proton Scattering Cross Section by the OLYMPUS Experiment. PHYSICAL REVIEW LETTERS 2021; 126:162501. [PMID: 33961478 DOI: 10.1103/physrevlett.126.162501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 03/17/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
We report the first measurement of the average of the electron-proton and positron-proton elastic scattering cross sections. This lepton charge-averaged cross section is insensitive to the leading effects of hard two-photon exchange, giving more robust access to the proton's electromagnetic form factors. The cross section was extracted from data taken by the OLYMPUS experiment at DESY, in which alternating stored electron and positron beams were scattered from a windowless gaseous hydrogen target. Elastic scattering events were identified from the coincident detection of the scattered lepton and recoil proton in a large-acceptance toroidal spectrometer. The luminosity was determined from the rates of Møller, Bhabha, and elastic scattering in forward electromagnetic calorimeters. The data provide some selectivity between existing form factor global fits and will provide valuable constraints to future fits.
Collapse
Affiliation(s)
- J C Bernauer
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Schmidt
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - B S Henderson
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - L D Ice
- Arizona State University, Tempe, Arizona 85287, USA
| | - D Khaneft
- Johannes Gutenberg-Universität, Mainz, Germany
| | - C O'Connor
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - R Russell
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - N Akopov
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - R Alarcon
- Arizona State University, Tempe, Arizona 85287, USA
| | - O Ates
- Hampton University, Hampton, Virginia 23668, USA
| | - A Avetisyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - R Beck
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - S Belostotski
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - J Bessuille
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - F Brinker
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - J R Calarco
- University of New Hampshire, Durham, New Hampshire 03824, USA
| | - V Carassiti
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - E Cisbani
- Istituto Nazionale di Fisica Nucleare sezione di Roma and Istituto Superiore di Sanità, Rome, Italy
| | - G Ciullo
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - M Contalbrigo
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - R De Leo
- Istituto Nazionale di Fisica Nucleare sezione di Bari, Bari, Italy
| | - J Diefenbach
- Hampton University, Hampton, Virginia 23668, USA
| | - T W Donnelly
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - K Dow
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - G Elbakian
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - P D Eversheim
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - S Frullani
- Istituto Nazionale di Fisica Nucleare sezione di Roma and Istituto Superiore di Sanità, Rome, Italy
| | - Ch Funke
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - G Gavrilov
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - B Gläser
- Johannes Gutenberg-Universität, Mainz, Germany
| | - N Görrissen
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - D K Hasell
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J Hauschildt
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - Ph Hoffmeister
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Y Holler
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - E Ihloff
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Izotov
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R Kaiser
- University of Glasgow, Glasgow, United Kingdom
| | - G Karyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - J Kelsey
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Kiselev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - P Klassen
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - A Krivshich
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - M Kohl
- Hampton University, Hampton, Virginia 23668, USA
| | - I Lehmann
- University of Glasgow, Glasgow, United Kingdom
| | - P Lenisa
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - D Lenz
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - S Lumsden
- University of Glasgow, Glasgow, United Kingdom
| | - Y Ma
- Johannes Gutenberg-Universität, Mainz, Germany
| | - F Maas
- Johannes Gutenberg-Universität, Mainz, Germany
| | - H Marukyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - O Miklukho
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R G Milner
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Movsisyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - M Murray
- University of Glasgow, Glasgow, United Kingdom
| | - Y Naryshkin
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | | | - R Perrino
- Istituto Nazionale di Fisica Nucleare sezione di Bari, Bari, Italy
| | - R P Redwine
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | - G Rosner
- University of Glasgow, Glasgow, United Kingdom
| | | | - B Seitz
- University of Glasgow, Glasgow, United Kingdom
| | - M Statera
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - A Thiel
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - H Vardanyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | | | - C Vidal
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Winnebeck
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - V Yeganov
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| |
Collapse
|
3
|
Gottschall M, Afzal F, Anisovich AV, Bayadilov D, Beck R, Bichow M, Brinkmann KT, Crede V, Dieterle M, Dietz F, Dutz H, Eberhardt H, Elsner D, Ewald R, Fornet-Ponse K, Friedrich S, Frommberger F, Gridnev A, Grüner M, Gutz E, Hammann C, Hannappel J, Hartmann J, Hillert W, Hoffmeister P, Honisch C, Jude T, Kammer S, Kalinowsky H, Keshelashvili I, Klassen P, Klein F, Klempt E, Koop K, Krusche B, Kube M, Lang M, Lopatin I, Mahlberg P, Makonyi K, Metag V, Meyer W, Müller J, Müllers J, Nanova M, Nikonov V, Novotny R, Piontek D, Reicherz G, Rostomyan T, Sarantsev A, Schmidt C, Schmieden H, Seifen T, Sokhoyan V, Spieker K, Thiel A, Thoma U, Urban M, Pee HV, Walther D, Wendel C, Werthmüller D, Wiedner U, Wilson A, Winnebeck A, Witthauer L, Wunderlich Y. Measurement of the helicity asymmetry E for the reaction γ p → π 0 p : The CBELSA/TAPS Collaboration. THE EUROPEAN PHYSICAL JOURNAL. A, HADRONS AND NUCLEI 2021; 57:40. [PMID: 33551676 PMCID: PMC7840663 DOI: 10.1140/epja/s10050-020-00334-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 11/28/2020] [Indexed: 06/12/2023]
Abstract
A measurement of the double-polarization observable E for the reaction γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C4 H9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range fromE γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.
Collapse
Affiliation(s)
- M. Gottschall
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - F. Afzal
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - A. V. Anisovich
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - D. Bayadilov
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R. Beck
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - M. Bichow
- Institut für Experimentalphysik I, Ruhr–Universität Bochum, Bochum, Germany
| | | | - V. Crede
- Department of Physics, Florida State University, Tallahassee, FL 32306 USA
| | - M. Dieterle
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - F. Dietz
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - H. Dutz
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - H. Eberhardt
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - D. Elsner
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - R. Ewald
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | | | - St. Friedrich
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - F. Frommberger
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - A. Gridnev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - M. Grüner
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - E. Gutz
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - Ch. Hammann
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - J. Hannappel
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - J. Hartmann
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - W. Hillert
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - Ph. Hoffmeister
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - Ch. Honisch
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - T. Jude
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - S. Kammer
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - H. Kalinowsky
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | | | - P. Klassen
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - F. Klein
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - E. Klempt
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - K. Koop
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - B. Krusche
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - M. Kube
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - M. Lang
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - I. Lopatin
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - P. Mahlberg
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - K. Makonyi
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - V. Metag
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - W. Meyer
- Institut für Experimentalphysik I, Ruhr–Universität Bochum, Bochum, Germany
| | - J. Müller
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - J. Müllers
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - M. Nanova
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - V. Nikonov
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R. Novotny
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - D. Piontek
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - G. Reicherz
- Institut für Experimentalphysik I, Ruhr–Universität Bochum, Bochum, Germany
| | - T. Rostomyan
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - A. Sarantsev
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - Ch. Schmidt
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - H. Schmieden
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - T. Seifen
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - V. Sokhoyan
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - K. Spieker
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - A. Thiel
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - U. Thoma
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - M. Urban
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - H. van Pee
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - D. Walther
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - Ch. Wendel
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - D. Werthmüller
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - U. Wiedner
- Institut für Experimentalphysik I, Ruhr–Universität Bochum, Bochum, Germany
| | - A. Wilson
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Department of Physics, Florida State University, Tallahassee, FL 32306 USA
| | - A. Winnebeck
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - L. Witthauer
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - Y. Wunderlich
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| |
Collapse
|
4
|
Abstract
In order to gain a better understanding of the dynamics inside the nucleon and of the non-perturbative regime of QCD, the nucleon excitation spectra and the properties of nucleon resonances are investigated. An essential experimental tool to achieve this goal is the study of different photoproduction reactions. Partial wave analyses are performed in order to obtain information about the contributing resonances. A complete experiment is needed to extract the underlying amplitudes unambiguously, which requires the measurement of carefully chosen single and double polarization observables in addition to the unpolarized cross section. The CBELSA/TAPS experiment in Bonn offers the possibility to measure several polarization observables using a linearly or circularly polarized photon beam and with a longitudinally or transversely polarized target. This contribution gives an overview of recently measured polarization observables in different final states. The impact of the new data is discussed.
Collapse
|
5
|
Henderson BS, Ice LD, Khaneft D, O'Connor C, Russell R, Schmidt A, Bernauer JC, Kohl M, Akopov N, Alarcon R, Ates O, Avetisyan A, Beck R, Belostotski S, Bessuille J, Brinker F, Calarco JR, Carassiti V, Cisbani E, Ciullo G, Contalbrigo M, De Leo R, Diefenbach J, Donnelly TW, Dow K, Elbakian G, Eversheim PD, Frullani S, Funke C, Gavrilov G, Gläser B, Görrissen N, Hasell DK, Hauschildt J, Hoffmeister P, Holler Y, Ihloff E, Izotov A, Kaiser R, Karyan G, Kelsey J, Kiselev A, Klassen P, Krivshich A, Lehmann I, Lenisa P, Lenz D, Lumsden S, Ma Y, Maas F, Marukyan H, Miklukho O, Milner RG, Movsisyan A, Murray M, Naryshkin Y, Perez Benito R, Perrino R, Redwine RP, Rodríguez Piñeiro D, Rosner G, Schneekloth U, Seitz B, Statera M, Thiel A, Vardanyan H, Veretennikov D, Vidal C, Winnebeck A, Yeganov V. Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering Determined by the OLYMPUS Experiment. PHYSICAL REVIEW LETTERS 2017; 118:092501. [PMID: 28306315 DOI: 10.1103/physrevlett.118.092501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Indexed: 06/06/2023]
Abstract
The OLYMPUS Collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, R_{2γ}, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01 GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of ≈20° to 80°. The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved gas electron multiplier and multiwire proportional chamber detectors at 12°, as well as symmetric Møller or Bhabha calorimeters at 1.29°. A total integrated luminosity of 4.5 fb^{-1} was collected. In the extraction of R_{2γ}, radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of R_{2γ}, presented here for a wide range of virtual photon polarization 0.456<ε<0.978, are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data.
Collapse
Affiliation(s)
- B S Henderson
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - L D Ice
- Arizona State University, Tempe, Arizona 85281, USA
| | - D Khaneft
- Johannes Gutenberg-Universität, 55099 Mainz, Germany
| | - C O'Connor
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - R Russell
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Schmidt
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J C Bernauer
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - M Kohl
- Hampton University, Hampton, Virginia 23668, USA
| | - N Akopov
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - R Alarcon
- Arizona State University, Tempe, Arizona 85281, USA
| | - O Ates
- Hampton University, Hampton, Virginia 23668, USA
| | - A Avetisyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - R Beck
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - S Belostotski
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - J Bessuille
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - F Brinker
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - J R Calarco
- University of New Hampshire, Durham, New Hampshire 03824, USA
| | - V Carassiti
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - E Cisbani
- Istituto Nazionale di Fisica Nucleare sezione di Roma and Istituto Superiore di Sanità, 00185 Rome, Italy
| | - G Ciullo
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - M Contalbrigo
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - R De Leo
- Istituto Nazionale di Fisica Nucleare sezione di Bari, 70126 Bari, Italy
| | - J Diefenbach
- Hampton University, Hampton, Virginia 23668, USA
| | - T W Donnelly
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - K Dow
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - G Elbakian
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - P D Eversheim
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - S Frullani
- Istituto Nazionale di Fisica Nucleare sezione di Roma and Istituto Superiore di Sanità, 00185 Rome, Italy
| | - Ch Funke
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - G Gavrilov
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - B Gläser
- Johannes Gutenberg-Universität, 55099 Mainz, Germany
| | - N Görrissen
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - D K Hasell
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J Hauschildt
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - Ph Hoffmeister
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - Y Holler
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - E Ihloff
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Izotov
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - R Kaiser
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G Karyan
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - J Kelsey
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Kiselev
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - P Klassen
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - A Krivshich
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - I Lehmann
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - P Lenisa
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - D Lenz
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - S Lumsden
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Y Ma
- Johannes Gutenberg-Universität, 55099 Mainz, Germany
| | - F Maas
- Johannes Gutenberg-Universität, 55099 Mainz, Germany
| | - H Marukyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - O Miklukho
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - R G Milner
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Movsisyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - M Murray
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Y Naryshkin
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | | | - R Perrino
- Istituto Nazionale di Fisica Nucleare sezione di Bari, 70126 Bari, Italy
| | - R P Redwine
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | - G Rosner
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - U Schneekloth
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - B Seitz
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - M Statera
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - A Thiel
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - H Vardanyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - D Veretennikov
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - C Vidal
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Winnebeck
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - V Yeganov
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| |
Collapse
|
6
|
|
7
|
|
8
|
Döring M, Mai M, Rönchen D. Towards Precision Spectroscopy of Baryonic Resonances. EPJ WEB OF CONFERENCES 2017. [DOI: 10.1051/epjconf/201713401002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
9
|
|
10
|
Costanza S. Recent results on doubly-polarised pion photoproduction and the GDH sum rule on the nucleon at MAMI. EPJ WEB OF CONFERENCES 2017. [DOI: 10.1051/epjconf/201716407034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
11
|
Hartmann J. Double polarisation experiments in meson photoproduction. EPJ WEB OF CONFERENCES 2016. [DOI: 10.1051/epjconf/201613001011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
12
|
Brambilla N, Eidelman S, Foka P, Gardner S, Kronfeld AS, Alford MG, Alkofer R, Butenschoen M, Cohen TD, Erdmenger J, Fabbietti L, Faber M, Goity JL, Ketzer B, Lin HW, Llanes-Estrada FJ, Meyer HB, Pakhlov P, Pallante E, Polikarpov MI, Sazdjian H, Schmitt A, Snow WM, Vairo A, Vogt R, Vuorinen A, Wittig H, Arnold P, Christakoglou P, Di Nezza P, Fodor Z, Garcia i Tormo X, Höllwieser R, Janik MA, Kalweit A, Keane D, Kiritsis E, Mischke A, Mizuk R, Odyniec G, Papadodimas K, Pich A, Pittau R, Qiu JW, Ricciardi G, Salgado CA, Schwenzer K, Stefanis NG, von Hippel GM, Zakharov VI. QCD and strongly coupled gauge theories: challenges and perspectives. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:2981. [PMID: 25972760 PMCID: PMC4413533 DOI: 10.1140/epjc/s10052-014-2981-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 07/05/2014] [Indexed: 05/17/2023]
Abstract
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.
Collapse
Affiliation(s)
- N. Brambilla
- Physik Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - S. Eidelman
- Budker Institute of Nuclear Physics, SB RAS, Novosibirsk , 630090 Russia
- Novosibirsk State University, Novosibirsk , 630090 Russia
| | - P. Foka
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany
| | - S. Gardner
- Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506-0055 USA
| | - A. S. Kronfeld
- Theoretical Physics Department, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510-5011 USA
| | - M. G. Alford
- Department of Physics, Washington University, St Louis, MO 63130 USA
| | | | - M. Butenschoen
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria
| | - T. D. Cohen
- Maryland Center for Fundamental Physics and Department of Physics, University of Maryland, College Park, MD 20742-4111 USA
| | - J. Erdmenger
- Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich, Germany
| | - L. Fabbietti
- Excellence Cluster “Origin and Structure of the Universe”, Technische Universität München, 85748 Garching, Germany
| | - M. Faber
- Atominstitut, Technische Universität Wien, 1040 Vienna, Austria
| | - J. L. Goity
- Hampton University, Hampton, VA 23668 USA
- Jefferson Laboratory, Newport News, VA 23606 USA
| | - B. Ketzer
- Physik Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
- Present Address: Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H. W. Lin
- Department of Physics, University of Washington, Seattle, WA 98195-1560 USA
| | - F. J. Llanes-Estrada
- Department Fisica Teorica I, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - H. B. Meyer
- PRISMA Cluster of Excellence, Institut für Kernphysik and Helmholtz Institut Mainz, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - P. Pakhlov
- Institute of Theoretical and Experimental Physics, Moscow, 117218 Russia
- Moscow Institute for Physics and Technology, Dolgoprudny, 141700 Russia
| | - E. Pallante
- Centre for Theoretical Physics, University of Groningen, 9747 AG Groningen, The Netherlands
| | - M. I. Polikarpov
- Institute of Theoretical and Experimental Physics, Moscow, 117218 Russia
- Moscow Institute for Physics and Technology, Dolgoprudny, 141700 Russia
| | - H. Sazdjian
- Institut de Physique Nucléaire CNRS/IN2P3, Université Paris-Sud, 91405 Orsay, France
| | - A. Schmitt
- Institut für Theoretische Physik, Technische Universität Wien, 1040 Vienna, Austria
| | - W. M. Snow
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408 USA
| | - A. Vairo
- Physik Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - R. Vogt
- Physics Division, Lawrence Livermore National Laboratory, Livermore, CA 94551 USA
- Physics Department, University of California, Davis, CA 95616 USA
| | - A. Vuorinen
- Department of Physics and Helsinki Institute of Physics, University of Helsinki, Helsinki, P.O. Box 64, 00014 Finland
| | - H. Wittig
- PRISMA Cluster of Excellence, Institut für Kernphysik and Helmholtz Institut Mainz, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - P. Arnold
- Department of Physics, University of Virginia, 382 McCormick Rd., P.O. Box 400714, Charlottesville, VA 22904-4714 USA
| | | | - P. Di Nezza
- Istituto Nazionale di Fisica Nucleare (INFN), Via E. Fermi 40, 00044 Frascati, Italy
| | - Z. Fodor
- Wuppertal University, 42119 Wuppertal, Germany
- Eötvös University, 1117 Budapest, Hungary
- Forschungszentrum Jülich, 52425 Jülich, Germany
| | - X. Garcia i Tormo
- Albert Einstein Center for Fundamental Physics, Institut für Theoretische Physik, Universität Bern, Sidlerstraße 5, 3012 Bern, Switzerland
| | - R. Höllwieser
- Atominstitut, Technische Universität Wien, 1040 Vienna, Austria
| | - M. A. Janik
- Faculty of Physics, Warsaw University of Technology, 00-662 Warsaw, Poland
| | - A. Kalweit
- European Organization for Nuclear Research (CERN), Geneva, Switzerland
| | - D. Keane
- Department of Physics, Kent State University, Kent, OH 44242 USA
| | - E. Kiritsis
- Crete Center for Theoretical Physics, Department of Physics, University of Crete, 71003 Heraklion, Greece
- Laboratoire APC, Université Paris Diderot, Paris Cedex 13, Sorbonne Paris-Cité , 75205 France
- Theory Group, Physics Department, CERN, 1211 Geneva 23, Switzerland
| | - A. Mischke
- Faculty of Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
| | - R. Mizuk
- Institute of Theoretical and Experimental Physics, Moscow, 117218 Russia
- Moscow Physical Engineering Institute, Moscow, 115409 Russia
| | - G. Odyniec
- Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720 USA
| | - K. Papadodimas
- Centre for Theoretical Physics, University of Groningen, 9747 AG Groningen, The Netherlands
| | - A. Pich
- IFIC, Universitat de València, CSIC, Apt. Correus 22085, 46071 València, Spain
| | - R. Pittau
- Departamento de Fisica Teorica y del Cosmos and CAFPE, Campus Fuentenueva s. n., Universidad de Granada, 18071 Granada, Spain
| | - J.-W. Qiu
- Physics Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- C. N. Yang Institute for Theoretical Physics and Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 USA
| | - G. Ricciardi
- Dipartimento di Fisica, Università degli Studi di Napoli Federico II, 80126 Napoli, Italy
- INFN, Sezione di Napoli, 80126 Napoli, Italy
| | - C. A. Salgado
- Departamento de Fisica de Particulas y IGFAE, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain
| | - K. Schwenzer
- Department of Physics, Washington University, St Louis, MO 63130 USA
| | - N. G. Stefanis
- Institut für Theoretische Physik II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - G. M. von Hippel
- PRISMA Cluster of Excellence, Institut für Kernphysik and Helmholtz Institut Mainz, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - V. I. Zakharov
- Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich, Germany
- Institute of Theoretical and Experimental Physics, Moscow, 117218 Russia
- Moscow Institute for Physics and Technology, Dolgoprudny, 141700 Russia
- School of Biomedicine, Far Eastern Federal University, Sukhanova str 8, Vladivostok, 690950 Russia
| |
Collapse
|
13
|
Hartmann J, Dutz H, Anisovich AV, Bayadilov D, Beck R, Becker M, Beloglazov Y, Berlin A, Bichow M, Böse S, Brinkmann KT, Crede V, Dieterle M, Eberhardt H, Elsner D, Fornet-Ponse K, Friedrich S, Frommberger F, Funke C, Gottschall M, Gridnev A, Grüner M, Gutz E, Hammann C, Hannappel J, Hannen V, Herick J, Hillert W, Hoffmeister P, Honisch C, Jahn O, Jude T, Käser A, Kaiser D, Kalinowsky H, Kalischewski F, Klassen P, Keshelashvili I, Klein F, Klempt E, Koop K, Krusche B, Kube M, Lang M, Lopatin I, Makonyi K, Messi F, Metag V, Meyer W, Müller J, Nanova M, Nikonov V, Novinski D, Novotny R, Piontek D, Rosenbaum C, Roth B, Reicherz G, Rostomyan T, Sarantsev A, Schmidt C, Schmieden H, Schmitz R, Seifen T, Sokhoyan V, Thämer P, Thiel A, Thoma U, Urban M, van Pee H, Walther D, Wendel C, Wiedner U, Wilson A, Winnebeck A, Witthauer L, Wunderlich Y. N(1520) 3/2(-) helicity amplitudes from an energy-independent multipole analysis based on new polarization data on photoproduction of neutral pions. PHYSICAL REVIEW LETTERS 2014; 113:062001. [PMID: 25148317 DOI: 10.1103/physrevlett.113.062001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Indexed: 06/03/2023]
Abstract
New data on the polarization observables T, P, and H for the reaction γp→pπ(0) are reported. The results are extracted from azimuthal asymmetries when a transversely polarized butanol target and a linearly polarized photon beam are used. The data were taken at the Bonn electron stretcher accelerator ELSA using the CBELSA/TAPS detector. These and earlier data are used to perform a truncated energy-independent partial wave analysis in sliced-energy bins. This energy-independent analysis is compared to the results from energy-dependent partial wave analyses.
Collapse
Affiliation(s)
- J Hartmann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Dutz
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - A V Anisovich
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - D Bayadilov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Becker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Y Beloglazov
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - A Berlin
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - M Bichow
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - S Böse
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - K-Th Brinkmann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - V Crede
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - M Dieterle
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - H Eberhardt
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - D Elsner
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - K Fornet-Ponse
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - St Friedrich
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - F Frommberger
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - Ch Funke
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Gottschall
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Gridnev
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - M Grüner
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - E Gutz
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - Ch Hammann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - J Hannappel
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - V Hannen
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - J Herick
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - W Hillert
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - Ph Hoffmeister
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Honisch
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - O Jahn
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - T Jude
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - A Käser
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - D Kaiser
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Kalinowsky
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - F Kalischewski
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - P Klassen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - I Keshelashvili
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - F Klein
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - E Klempt
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - K Koop
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - B Krusche
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - M Kube
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Lang
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - I Lopatin
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - K Makonyi
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - F Messi
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - V Metag
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - W Meyer
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - J Müller
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Nanova
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - V Nikonov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - D Novinski
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - R Novotny
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - D Piontek
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - C Rosenbaum
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - B Roth
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - G Reicherz
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - T Rostomyan
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - A Sarantsev
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - Ch Schmidt
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Schmieden
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - R Schmitz
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - T Seifen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - V Sokhoyan
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ph Thämer
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - U Thoma
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Urban
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H van Pee
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - D Walther
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Wendel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - U Wiedner
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - A Wilson
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A Winnebeck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - L Witthauer
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - Y Wunderlich
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| |
Collapse
|
14
|
Strakovsky I, Briscoe W, Kudryavtsev A, Tarasov V, Workman R. SAID analysis of meson photoproduction: Determination of neutron and proton EM couplings. EPJ WEB OF CONFERENCES 2014. [DOI: 10.1051/epjconf/20147304003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
15
|
|
16
|
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. PHYSICAL REVIEW LETTERS 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] [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.
Collapse
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
| |
Collapse
|
17
|
Gottschall M, Anisovich AV, Bantes B, Bayadilov D, Beck R, Bichow M, Böse S, Brinkmann KT, Challand T, Crede V, Dietz F, Dutz H, Eberhardt H, Elsner D, Ewald R, Fornet-Ponse K, Friedrich S, Frommberger F, Funke C, Gridnev A, Grüner M, Gutz E, Hammann C, Hannappel J, Hartmann J, Hillert W, Hoffmeister P, Honisch C, Jaegle I, Kaiser D, Kalinowsky H, Kammer S, Keshelashvili I, Klein F, Klempt E, Koop K, Krusche B, Kube M, Lang M, Lopatin I, Maghrbi Y, Makonyi K, Metag V, Meyer W, Müller J, Nanova M, Nikonov V, Novotny R, Piontek D, Reicherz G, Rostomyan T, Sarantsev A, Schaepe S, Schmidt C, Schmieden H, Schmitz R, Seifen T, Sokhoyan V, Thiel A, Thoma U, Urban M, van Pee H, Walther D, Wendel C, Wiedner U, Wilson A, Winnebeck A. First measurement of the helicity asymmetry for γp → pπ0 in the resonance region. PHYSICAL REVIEW LETTERS 2014; 112:012003. [PMID: 24483889 DOI: 10.1103/physrevlett.112.012003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Indexed: 06/03/2023]
Abstract
The first measurement of the helicity dependence of the photoproduction cross section of single neutral pions off protons is reported for photon energies from 600 to 2300 MeV, covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, and BnGa partial wave analyses. Strikingly large differences between data and predictions are observed, which are traced to differences in the helicity amplitudes of well-known and established resonances. Precise values for the helicity amplitudes of several resonances are reported.
Collapse
Affiliation(s)
- M Gottschall
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A V Anisovich
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - B Bantes
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - D Bayadilov
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - R Beck
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Bichow
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - S Böse
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - K-Th Brinkmann
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - Th Challand
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - V Crede
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - F Dietz
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - H Dutz
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - H Eberhardt
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - D Elsner
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - R Ewald
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - K Fornet-Ponse
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - St Friedrich
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - F Frommberger
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - Ch Funke
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Gridnev
- Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - M Grüner
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - E Gutz
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - Ch Hammann
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - J Hannappel
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - J Hartmann
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - W Hillert
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - Ph Hoffmeister
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Honisch
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - I Jaegle
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - D Kaiser
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Kalinowsky
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - S Kammer
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - I Keshelashvili
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - F Klein
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - E Klempt
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - K Koop
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - B Krusche
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - M Kube
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Lang
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - I Lopatin
- Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - Y Maghrbi
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - K Makonyi
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - V Metag
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - W Meyer
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - J Müller
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Nanova
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - V Nikonov
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - R Novotny
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - D Piontek
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - G Reicherz
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - T Rostomyan
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Sarantsev
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - St Schaepe
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Schmidt
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Schmieden
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - R Schmitz
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - T Seifen
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - V Sokhoyan
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Thiel
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - U Thoma
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Urban
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H van Pee
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - D Walther
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Wendel
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - U Wiedner
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - A Wilson
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A Winnebeck
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| |
Collapse
|
18
|
Krusche B. Latest results from meson photoproduction at ELSA and MAMI. EPJ WEB OF CONFERENCES 2014. [DOI: 10.1051/epjconf/20147301002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
19
|
|
20
|
Thiel A. The double polarization program of CBELSA/TAPS. EPJ WEB OF CONFERENCES 2014. [DOI: 10.1051/epjconf/20147304013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
21
|
Crede V, Roberts W. Progress towards understanding baryon resonances. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2013; 76:076301. [PMID: 23787948 DOI: 10.1088/0034-4885/76/7/076301] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The composite nature of baryons manifests itself in the existence of a rich spectrum of excited states, in particular in the important mass region 1-2 GeV for the light-flavoured baryons. The properties of these resonances can be identified by systematic investigations using electromagnetic and strong probes, primarily with beams of electrons, photons, and pions. After decades of research, the fundamental degrees of freedom underlying the baryon excitation spectrum are still poorly understood. The search for hitherto undiscovered but predicted resonances continues at many laboratories around the world. Recent results from photo- and electroproduction experiments provide intriguing indications for new states and shed light on the structure of some of the known nucleon excitations. The continuing study of available data sets with consideration of new observables and improved analysis tools have also called into question some of the earlier findings in baryon spectroscopy. Other breakthrough measurements have been performed in the heavy-baryon sector, which has seen a fruitful period in recent years, in particular at the B factories and the Tevatron. First results from the large hadron collider indicate rapid progress in the field of bottom baryons. In this review, we discuss the recent experimental progress and give an overview of theoretical approaches.
Collapse
Affiliation(s)
- V Crede
- Florida State University, Department of Physics, Tallahassee, FL 32306, USA.
| | | |
Collapse
|
22
|
Workman RL, Paris MW, Briscoe WJ, Strakovsky II. Comment on "Well-established nucleon resonances revisited by double-polarization measurements". PHYSICAL REVIEW LETTERS 2013; 110:169101. [PMID: 23679651 DOI: 10.1103/physrevlett.110.169101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Indexed: 06/02/2023]
|
23
|
Thiel A, Anisovich AV, Bayadilov D, Bantes B, Beck R, Beloglazov Y, Bichow M, Böse S, Brinkmann KT, Challand T, Crede V, Dietz F, Drexler P, Dutz H, Eberhardt H, Elsner D, Ewald R, Fornet-Ponse K, Friedrich S, Frommberger F, Funke C, Gottschall M, Grüner M, Gutz E, Hammann C, Hannappel J, Hartmann J, Hillert W, Hoffmeister P, Honisch C, Jaegle I, Jürgensen I, Kaiser D, Kalinowsky H, Kalischewski F, Kammer S, Keshelashvili I, Kleber V, Klein F, Klempt E, Krusche B, Lang M, Lopatin I, Maghrbi Y, Makonyi K, Metag V, Meyer W, Müller J, Nanova M, Nikonov V, Novotny R, Piontek D, Reicherz G, Sarantsev A, Schmidt C, Schmieden H, Seifen T, Sokhoyan V, Sumachev V, Thoma U, vanPee H, Walther D, Wendel C, Wiedner U, Wilson A, Winnebeck A, Wunderlich Y. Thiel et al. reply:. PHYSICAL REVIEW LETTERS 2013; 110:169102. [PMID: 23679652 DOI: 10.1103/physrevlett.110.169102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Indexed: 06/02/2023]
|