Physics Letters B (Dec 2023)
Neutron polarisation transfer, Cx′, in π+ photoproduction off the proton, d(γ⊙,n→π+)nspec
- M. Bashkanov,
- D.P. Watts,
- S.J.D. Kay,
- S. Abt,
- P. Achenbach,
- P. Adlarson,
- F. Afzal,
- Z. Ahmed,
- C.S. Akondi,
- J.R.M. Annand,
- R. Beck,
- M. Biroth,
- N. Borisov,
- A. Braghieri,
- W.J. Briscoe,
- F. Cividini,
- C. Collicott,
- S. Costanza,
- A. Denig,
- E.J. Downie,
- P. Drexler,
- S. Fegan,
- A. Fix,
- S. Gardner,
- D. Ghosal,
- D.I. Glazier,
- I. Gorodnov,
- W. Gradl,
- D. Gurevich,
- L. Heijkenskjöld,
- D. Hornidge,
- G.M. Huber,
- V.L. Kashevarov,
- M. Korolija,
- B. Krusche,
- A. Lazarev,
- K. Livingston,
- S. Lutterer,
- I.J.D. MacGregor,
- D.M. Manley,
- P.P. Martel,
- R. Miskimen,
- E. Mornacchi,
- C. Mullen,
- A. Neganov,
- A. Neiser,
- M. Ostrick,
- P.B. Otte,
- D. Paudyal,
- P. Pedroni,
- T. Rostomyan,
- V. Sokhoyan,
- K. Spieker,
- O. Steffen,
- I.I. Strakovsky,
- T. Strub,
- I. Supek,
- A. Thiel,
- M. Thiel,
- A. Thomas,
- Yu.A. Usov,
- S. Wagner,
- N.K. Walford,
- J. Wettig,
- M. Wolfes,
- R.L. Workman,
- N. Zachariou
Affiliations
- M. Bashkanov
- Department of Physics, University of York, Heslington, York, Y010 5DD, UK; Corresponding author.
- D.P. Watts
- Department of Physics, University of York, Heslington, York, Y010 5DD, UK
- S.J.D. Kay
- University of Regina, Regina, SK S4S-0A2 Canada
- 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
- F. Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, D-53115 Bonn, Germany
- Z. Ahmed
- University of Regina, Regina, SK S4S-0A2 Canada
- C.S. Akondi
- Kent State University, Kent, OH 44242, USA
- J.R.M. Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
- R. Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University 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, 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
- Dipartimento di Fisica, Università di Pavia, I-27100 Pavia, Italy; INFN Sezione di Pavia, I-27100 Pavia, Italy
- A. Denig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- E.J. Downie
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
- P. Drexler
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany; Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- S. Fegan
- Department of Physics, University of York, Heslington, York, Y010 5DD, UK
- A. Fix
- Tomsk Polytechnic University, 634034 Tomsk, Russia
- S. Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
- 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, UK
- 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 S4S-0A2 Canada
- V.L. Kashevarov
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany; Joint Institute for Nuclear Research, 141980 Dubna, Russia
- 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, UK
- 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, UK
- D.M. Manley
- Kent State University, Kent, OH 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, MA 01003, USA
- 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, UK
- A. Neganov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
- A. Neiser
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- 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 S4S-0A2 Canada
- P. Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
- T. Rostomyan
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
- V. Sokhoyan
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- K. Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, D-53115 Bonn, 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 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
- J. Wettig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- M. Wolfes
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- R.L. Workman
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
- N. Zachariou
- Department of Physics, University of York, Heslington, York, Y010 5DD, UK
- Journal volume & issue
-
Vol. 847
p. 138283
Abstract
We report a first measurement of the double-polarisation observable, Cx′, in π+ photoproduction off the proton. The Cx′ double-polarisation observable represents the transfer of polarisation from a circularly polarised photon beam to the recoiling neutron. The MAMI circularly polarised photon beam impinged on a liquid deuterium target cell, with reaction products detected in the Crystal Ball calorimeter. Ancillary apparatus surrounding the target provided tracking, particle identification and determination of recoil nucleon polarisation. The Cx′ observable is determined for photon energies 800-1400 MeV, providing new constraints on models aiming to elucidate the spectrum and properties of nucleon resonances. This is the first determination of any polarisation observable from the beam-recoil group of observables for this reaction. Inclusion of the new data in the database of the SAID partial wave analysis shifted the solution to a new global minima which, not only gives better agreement with the current data, but also improves the description of a range of other single and double polarisation observables for charged pion photoproduction.
