Physics Letters B (Sep 2015)
The isospin structure of photoproduction of πη pairs from the nucleon in the threshold region
- A. Käser,
- J. Ahrens,
- J.R.M. Annand,
- H.J. Arends,
- K. Bantawa,
- P.A. Bartolome,
- R. Beck,
- V. Bekrenev,
- H. Berghäuser,
- A. Braghieri,
- D. Branford,
- W.J. Briscoe,
- J. Brudvik,
- S. Cherepnya,
- S. Costanza,
- B. Demissie,
- M. Dieterle,
- E.J. Downie,
- P. Drexler,
- L.V. Fil'kov,
- A. Fix,
- D.I. Glazier,
- D. Hamilton,
- E. Heid,
- D. Hornidge,
- D. Howdle,
- G.M. Huber,
- O. Jahn,
- I. Jaegle,
- T.C. Jude,
- V.L. Kashevarov,
- I. Keshelashvili,
- R. Kondratiev,
- M. Korolija,
- S.P. Kruglov,
- B. Krusche,
- V. Lisin,
- K. Livingston,
- I.J.D. MacGregor,
- Y. Maghrbi,
- J. Mancell,
- D.M. Manley,
- Z. Marinides,
- J.C. McGeorge,
- E. McNicoll,
- D. Mekterovic,
- V. Metag,
- S. Micanovic,
- D.G. Middleton,
- A. Mushkarenkov,
- A. Nikolaev,
- R. Novotny,
- M. Oberle,
- M. Ostrick,
- P. Otte,
- B. Oussena,
- P. Pedroni,
- F. Pheron,
- A. Polonski,
- S.N. Prakhov,
- J. Robinson,
- G. Rosner,
- T. Rostomyan,
- S. Schumann,
- M.H. Sikora,
- D.I. Sober,
- A. Starostin,
- I. Supek,
- M. Thiel,
- A. Thomas,
- M. Unverzagt,
- D.P. Watts,
- D. Werthmüller,
- L. Witthauer
Affiliations
- A. Käser
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- J. Ahrens
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- J.R.M. Annand
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- H.J. Arends
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- K. Bantawa
- Kent State University, Kent, OH 44242, USA
- P.A. Bartolome
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- R. Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, D-53115 Bonn, Germany
- V. Bekrenev
- Petersburg Nuclear Physics Institute, RU-188300 Gatchina, Russia
- H. Berghäuser
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
- A. Braghieri
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
- D. Branford
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
- W.J. Briscoe
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
- J. Brudvik
- University of California Los Angeles, Los Angeles, CA 90095-1547, USA
- S. Cherepnya
- Lebedev Physical Institute, RU-119991 Moscow, Russia
- S. Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
- B. Demissie
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
- M. Dieterle
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- E.J. Downie
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- P. Drexler
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
- L.V. Fil'kov
- Lebedev Physical Institute, RU-119991 Moscow, Russia
- A. Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, Tomsk, Russia
- D.I. Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- D. Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- E. Heid
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- D. Hornidge
- Mount Allison University, Sackville, New Brunswick E4L1E6, Canada
- D. Howdle
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- G.M. Huber
- University of Regina, Regina, SK S4S-0A2, Canada
- O. Jahn
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- I. Jaegle
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- T.C. Jude
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
- V.L. Kashevarov
- Lebedev Physical Institute, RU-119991 Moscow, Russia
- I. Keshelashvili
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- R. Kondratiev
- Institute for Nuclear Research, RU-125047 Moscow, Russia
- M. Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
- S.P. Kruglov
- Petersburg Nuclear Physics Institute, RU-188300 Gatchina, Russia
- B. Krusche
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- V. Lisin
- Institute for Nuclear Research, RU-125047 Moscow, Russia
- K. Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- I.J.D. MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- Y. Maghrbi
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- J. Mancell
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- D.M. Manley
- Kent State University, Kent, OH 44242, USA
- Z. Marinides
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
- J.C. McGeorge
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- E. McNicoll
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- D. Mekterovic
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
- V. Metag
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
- S. Micanovic
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
- D.G. Middleton
- Mount Allison University, Sackville, New Brunswick E4L1E6, Canada
- A. Mushkarenkov
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
- A. Nikolaev
- Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, D-53115 Bonn, Germany
- R. Novotny
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, 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. Otte
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- B. Oussena
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- P. Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
- F. Pheron
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- A. Polonski
- Institute for Nuclear Research, RU-125047 Moscow, Russia
- S.N. Prakhov
- University of California Los Angeles, Los Angeles, CA 90095-1547, USA
- J. Robinson
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- G. Rosner
- SUPA School of Physics and Astronomy, University of Glasgow, G12 8QQ, United Kingdom
- T. Rostomyan
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- S. Schumann
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- M.H. Sikora
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
- D.I. Sober
- The Catholic University of America, Washington, DC 20064, USA
- A. Starostin
- University of California Los Angeles, Los Angeles, CA 90095-1547, USA
- I. Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
- M. Thiel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- A. Thomas
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- M. Unverzagt
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- D.P. Watts
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
- D. Werthmüller
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- L. Witthauer
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
- DOI
- https://doi.org/10.1016/j.physletb.2015.07.007
- Journal volume & issue
-
Vol. 748,
no. C
pp. 244 – 250
Abstract
Photoproduction of πη-pairs from nucleons has been investigated from threshold up to incident photon energies of ≈ 1.4 GeV. The quasi-free reactions γp→pπ0η, γn→nπ0η, γp→nπ+η, and γn→pπ−η were for the first time measured from nucleons bound in the deuteron. The corresponding reactions from a free-proton target were also studied to investigate final-state interaction effects (for neutral pions the free-proton results could be compared to previous measurements; the γp→nπ+η reaction was measured for the first time). For the π0η final state coherent production via the γd→dπ0η reaction was also investigated. The experiments were performed at the tagged photon beam of the Mainz MAMI accelerator using an almost 4π coverage electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. The total cross sections for the four different final states obey the relation σ(pπ0η)≈σ(nπ0η)≈2σ(pπ−η)≈2σ(nπ+η) as expected for a dominant contribution from a Δ⋆→ηΔ(1232)→πηN reaction chain, which is also supported by the shapes of the invariant-mass distributions of nucleon–meson and π–η pairs. The experimental results are compared to the predictions from an isobar reaction model.
