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Jermann N, Krusche B, Metag V, Afzal F, Badea M, Beck R, Bielefeldt P, Bieling J, Biroth M, Blanke E, Borisov N, Bornstein M, Brinkmann KT, Ciupka S, Crede V, Dolzhikov A, Drexler P, Dutz H, Elsner D, Fedorov A, Frommberger F, Gardner S, Ghosal D, Goertz S, Gorodnov I, Grüner M, Hammann C, Hartmann J, Hillert W, Hoffmeister P, Honisch C, Jude TC, Kalischewski F, Ketzer B, Klassen P, Klein F, Klempt E, Knaust J, Kolanus N, Kreit J, Krönert P, Lang M, Lazarev AB, Livingston K, Lutterer S, Mahlberg P, Meier C, Meyer W, Mitlasoczki B, Müllers J, Nanova M, Neganov A, Nikonov K, Noël JF, Ostrick M, Ottnad J, Otto B, Penman G, Poller T, Proft D, Reicherz G, Reinartz N, Richter L, Runkel S, Salisbury B, Sarantsev AV, Schaab D, Schmidt C, Schmieden H, Schultes J, Seifen T, Spieker K, Stausberg N, Steinacher M, Taubert F, Thiel A, Thoma U, Thomas A, Urban M, Urff G, Usov Y, van Pee H, Wang YC, Wendel C, Wiedner U, Wunderlich Y. Measurement of polarization observables T, P, and H in π0 and η photoproduction off quasi-free nucleons. Eur Phys J A Hadron Nucl 2023; 59:232. [PMID: 37860634 PMCID: PMC10582157 DOI: 10.1140/epja/s10050-023-01134-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 09/21/2023] [Indexed: 10/21/2023]
Abstract
The target asymmetry T, recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive π 0 and η photoproduction off quasi-free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γ p → π 0 p and γ p → η p reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the η n system at W = 1.68 GeV . A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S 11 ( 1535 ) and S 11 ( 1650 ) resonances within the S 11 -partial wave.
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Affiliation(s)
- N. Jermann
- Department of Physics, University of Basel, Basel, Switzerland
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - B. Krusche
- Department of Physics, University of Basel, Basel, Switzerland
| | - V. Metag
- II. Physikalisches Institut, University of Giessen, Giessen, Germany
| | - F. Afzal
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - M. Badea
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - R. Beck
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - P. Bielefeldt
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - J. Bieling
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - M. Biroth
- Institut für Kernphysik, University of Mainz, Mainz, Germany
| | - E. Blanke
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - N. Borisov
- Joint Institute for Nuclear Research, Dubna, Russia
| | - M. Bornstein
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - K.-T. Brinkmann
- II. Physikalisches Institut, University of Giessen, Giessen, Germany
| | - S. Ciupka
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - V. Crede
- Department of Physics, Florida State University, Tallahassee, USA
| | - A. Dolzhikov
- Joint Institute for Nuclear Research, Dubna, Russia
| | - P. Drexler
- Institut für Kernphysik, University of Mainz, Mainz, Germany
| | - H. Dutz
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - D. Elsner
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - A. Fedorov
- Joint Institute for Nuclear Research, Dubna, Russia
| | - F. Frommberger
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - S. Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, UK
| | - D. Ghosal
- Department of Physics, University of Basel, Basel, Switzerland
- Present Address: resent address: University of Liverpool, Liverpool, UK
| | - S. Goertz
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - I. Gorodnov
- Joint Institute for Nuclear Research, Dubna, Russia
| | - M. Grüner
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - C. Hammann
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - J. Hartmann
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - W. Hillert
- Physikalisches Institut, University of Bonn, Bonn, Germany
- Present Address: resent address: University of Hamburg, Hamburg, Germany
| | - P. Hoffmeister
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - C. Honisch
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - T. C. Jude
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - F. Kalischewski
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - B. Ketzer
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - P. Klassen
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - F. Klein
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - E. Klempt
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - J. Knaust
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - N. Kolanus
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - J. Kreit
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - P. Krönert
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - M. Lang
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | | | - K. Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, UK
| | - S. Lutterer
- Department of Physics, University of Basel, Basel, Switzerland
- Present Address: resent address: Ruhr University Bochum, Bochum, Germany
| | - P. Mahlberg
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - C. Meier
- Department of Physics, University of Basel, Basel, Switzerland
| | - W. Meyer
- Institut für Experimentalphysik I, Ruhr University Bochum, Bochum, Germany
| | - B. Mitlasoczki
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - J. Müllers
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - M. Nanova
- II. Physikalisches Institut, University of Giessen, Giessen, Germany
| | - A. Neganov
- Joint Institute for Nuclear Research, Dubna, Russia
| | - K. Nikonov
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - J. F. Noël
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - M. Ostrick
- Institut für Kernphysik, University of Mainz, Mainz, Germany
| | - J. Ottnad
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - B. Otto
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - G. Penman
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, UK
| | - T. Poller
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - D. Proft
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - G. Reicherz
- Institut für Experimentalphysik I, Ruhr University Bochum, Bochum, Germany
| | - N. Reinartz
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - L. Richter
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - S. Runkel
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - B. Salisbury
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - A. V. Sarantsev
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - D. Schaab
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - C. Schmidt
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - H. Schmieden
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - J. Schultes
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - T. Seifen
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - K. Spieker
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - N. Stausberg
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - M. Steinacher
- Department of Physics, University of Basel, Basel, Switzerland
| | - F. Taubert
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - A. Thiel
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - U. Thoma
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - A. Thomas
- Institut für Kernphysik, University of Mainz, Mainz, Germany
| | - M. Urban
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - G. Urff
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - Y. Usov
- Joint Institute for Nuclear Research, Dubna, Russia
| | - H. van Pee
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - Y. C. Wang
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - C. Wendel
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - U. Wiedner
- Institut für Experimentalphysik I, Ruhr University Bochum, Bochum, Germany
| | - Y. Wunderlich
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
| | - CBELSA/TAPS Collaboration
- Department of Physics, University of Basel, Basel, Switzerland
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, Bonn, Germany
- II. Physikalisches Institut, University of Giessen, Giessen, Germany
- Institut für Kernphysik, University of Mainz, Mainz, Germany
- Joint Institute for Nuclear Research, Dubna, Russia
- Department of Physics, Florida State University, Tallahassee, USA
- Physikalisches Institut, University of Bonn, Bonn, Germany
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, UK
- Institut für Experimentalphysik I, Ruhr University Bochum, Bochum, Germany
- Present Address: resent address: University of Liverpool, Liverpool, UK
- Present Address: resent address: University of Hamburg, Hamburg, Germany
- Present Address: resent address: Ruhr University Bochum, Bochum, Germany
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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. Eur Phys J A Hadron Nucl 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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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Afzal F, Wunderlich Y, Anisovich AV, Bayadilov D, Beck R, Becker M, Blanke E, Brinkmann KT, Ciupka S, Crede V, Dieterle M, Dutz H, Elsner D, Friedrich S, Frommberger F, Gridnev A, Gottschall M, Grüner M, Gutz E, Hammann C, Hannappel J, Hartmann J, Hillert W, Hoff J, Hoffmeister P, Honisch C, Jude T, Kalinowsky H, Kalischewski F, Keshelashvili I, Klassen P, Klein F, Klempt E, Koop K, Kroenert P, Krusche B, Lang M, Lopatin I, Mahlberg P, Meißner UG, Messi F, Metag V, Meyer W, Mitlasóczki B, Müller J, Müllers J, Nanova M, Nikonov K, Nikonov V, Novinskiy V, Novotny R, Piontek D, Reicherz G, Richter L, Rönchen D, Rostomyan T, Salisbury B, Sarantsev A, Schaab D, Schmidt C, Schmieden H, Schultes J, Seifen T, Sokhoyan V, Sowa C, Spieker K, Stausberg N, Thiel A, Thoma U, Triffterer T, Urban M, Urff G, van Pee H, Walther D, Wendel C, Wiedner U, Wilson A, Winnebeck A, Witthauer L. Observation of the pη^{'} Cusp in the New Precise Beam Asymmetry Σ Data for γp→pη. Phys Rev Lett 2020; 125:152002. [PMID: 33095637 DOI: 10.1103/physrevlett.125.152002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/24/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.
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Affiliation(s)
- F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - Y Wunderlich
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - A V Anisovich
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - D Bayadilov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - M Becker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - E Blanke
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - K-Th Brinkmann
- II. Physikalisches Institut, Universität Giessen, Germany
| | - S Ciupka
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - V Crede
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - M Dieterle
- Physikalisches Institut, Universität Basel, Switzerland
| | - H Dutz
- Physikalisches Institut, Universität Bonn, Germany
| | - D Elsner
- Physikalisches Institut, Universität Bonn, Germany
| | - S Friedrich
- II. Physikalisches Institut, Universität Giessen, Germany
| | | | - A Gridnev
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - M Gottschall
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - M Grüner
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - E Gutz
- II. Physikalisches Institut, Universität Giessen, Germany
| | - C Hammann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - J Hannappel
- Physikalisches Institut, Universität Bonn, Germany
| | - J Hartmann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - W Hillert
- Physikalisches Institut, Universität Bonn, Germany
| | - J Hoff
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - P Hoffmeister
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - C Honisch
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - T Jude
- Physikalisches Institut, Universität Bonn, Germany
| | - H Kalinowsky
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - F Kalischewski
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | | | - P Klassen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - F Klein
- Physikalisches Institut, Universität Bonn, Germany
| | - E Klempt
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - K Koop
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - P Kroenert
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - B Krusche
- Physikalisches Institut, Universität Basel, Switzerland
| | - M Lang
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - I Lopatin
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - P Mahlberg
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - U-G Meißner
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - F Messi
- Physikalisches Institut, Universität Bonn, Germany
| | - V Metag
- II. Physikalisches Institut, Universität Giessen, Germany
| | - W Meyer
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - B Mitlasóczki
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - J Müller
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - J Müllers
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - M Nanova
- II. Physikalisches Institut, Universität Giessen, Germany
| | - K Nikonov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - V Nikonov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - V Novinskiy
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R Novotny
- II. Physikalisches Institut, Universität Giessen, Germany
| | - D Piontek
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - G Reicherz
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - L Richter
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - D Rönchen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - T Rostomyan
- Physikalisches Institut, Universität Basel, Switzerland
| | - B Salisbury
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - A Sarantsev
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - D Schaab
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - C Schmidt
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - H Schmieden
- Physikalisches Institut, Universität Bonn, Germany
| | - J Schultes
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - T Seifen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - V Sokhoyan
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - C Sowa
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - N Stausberg
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - U Thoma
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - T Triffterer
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - M Urban
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - G Urff
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - H van Pee
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - D Walther
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - Ch Wendel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - U Wiedner
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - A Wilson
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A Winnebeck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - L Witthauer
- Physikalisches Institut, Universität Basel, Switzerland
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4
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Abstract
A successive pattern of nuclear divisions that result in mitotic waves has been observed within the coenocytic nonarticulated laticifers of embryos of Euphorbia marginata Pursh. These waves originate independently in the cotyledonary or hypocotyl portion of the laticifer and exhibit uni-or bidirectional movement at variable velocities. Individual nuclei or groups of neighoring nuclei in a laticifer were observed in a sequence of mitotic stages ranging from prophase to telophase; division activity varied with individual laticifers in an embryo. Two mitotic patterns were apparent in the embryo: a random pattern associated with various cells in the meristematic area, and a successive pattern restricted to the laticifer. A substance, synthesized by and restricted to the laticifer, may be associated with this mitotic pattern.
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5
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Kim E, Mahlberg P. Immunochemical localization of tetrahydrocannabinol (THC) in cryofixed glandular trichomes of Cannabis (Cannabaceae). Am J Bot 1997. [PMID: 21708587 DOI: 10.2307/2446007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Delta 9-tetrahydrocannabinol (THC) localization in glandular trichomes and bracteal tissues of Cannabis, prepared by high pressure cryofixation-cryosubstitution, was examined with a monoclonal antibody-colloidal gold probe by electron microscopy (EM). The antibody detected THC in the outer wall of disc cells during the presecretory cavity phase of gland development. Upon formation of the secretory cavity, the immunolabel detected THC in the disc cell wall facing the cavity as well as the subcuticular wall and cuticle throughout development of the secretory cavity. THC was detected in the fibrillar matrix associated with the disc cell and with this matrix in the secretory cavity. The antibody identified THC on the surface of secretory vesicles, but not in the secretory vesicles. Gold label also was localized in the anticlinal walls between adjacent disc cells and in the wall of dermal and mesophyll cells of the bract. Grains were absent or detected only occasionally in the cytoplasm of disc or other cells of the bract. No THC was detected in controls. These results indicate THC to be a natural product secreted particularly from disc cells and accumulated in the cell wall, the fibrillar matrix and surface feature of vesicles in the secretory cavity, the subcuticular wall, and the cuticle of glandular trichomes. THC, among other chemicals, accumulated in the cuticle may serve as a plant recognition signal to other organisms in the environment.
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6
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Mahlberg P. Scanning electron microscopy of starch grains from latex of Euphorbia terracina and E. tirucalli. Planta 1973; 110:77-80. [PMID: 24474314 DOI: 10.1007/bf00386925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/1972] [Indexed: 06/03/2023]
Abstract
The morphology of starch grains isolated from the latex of 2 species of Euphorbia was compared by scanning electron microscopy. In E. terracina they are elongated and greater, in diameter at the midregion than at the tips while in E. tirucalli they are osteoid. Starch grains varied in size in both, species although in E. tirucalli the largest grains, which measured 49 μ, were approximately twice the length of those in E. terracina (27 μ).
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Affiliation(s)
- P Mahlberg
- Department of Plant Sciences, Indiana University, 47401, Bloomington, Indiana, USA
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7
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Abstract
Whole and fractionated latex of Asclepias syriaca was tested for antimicrobial or growth-promoting activity with 16 genera and species of bacteria. Latex and extracted fractions (distilled water, acetic acid, sodium bicarbonate, sulfuric acid, and ethyl ether) possessed no detectable antimicrobial activity. Comparison of growth curves of selected bacteria incubated with serum and rubber fractions, as well as controls, revealed no detectable inhibition of growth, except for a slight inhibitory response to autoclaved serum. Most bacteria were capable of utilizing latex for a substrate as indicated by the increased growth rate in the exponential phase. The stationary phase was entered simultaneously by both the treated cultures and the controls. Various bacteria cultured in a litmus latex mixture yielded populations which ranged from <10(4) organisms/ml for Lactobacillus casei, Staphylococcus aureus and Micrococcus lysodeikticus to 1.1 x 10(10) organisms/ml for Clostridium acetobutylicum. Whole latex, as well as the serum and rubber fractions, support the growth of various bacteria, but under field conditions there is no evidence for systemic infection of this type of cell by bacteria.
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