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Measurements of the γ*p → Δ reaction at low Q2

  • N. SparverisEmail author
  • S. Stave
  • P. Achenbach
  • C. Ayerbe Gayoso
  • D. Baumann
  • J. Bernauer
  • A. M. Bernstein
  • R. Böhm
  • D. Bosnar
  • T. Botto
  • A. Christopoulou
  • D. Dale
  • M. Ding
  • M. O. Distler
  • L. Doria
  • J. Friedrich
  • A. Karabarbounis
  • M. Makek
  • H. Merkel
  • U. Müller
  • I. Nakagawa
  • R. Neuhausen
  • L. Nungesser
  • C. N. Papanicolas
  • A. Piegsa
  • J. Pochodzalla
  • M. Potokar
  • M. Seimetz
  • S. Širca
  • S. Stiliaris
  • Th. Walcher
  • M. Weis
Regular Article - Experimental Physics

Abstract

We report new p(e, e′p)π° measurements in the Δ +(1232) resonance at the low momentum transfer region utilizing the magnetic spectrometers of the A1 Collaboration at MAMI. The mesonic cloud dynamics are predicted to be dominant and appreciably changing in this region while the momentum transfer is sufficiently low to be able to test chiral effective field theory calculations. The results disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations with pion cloud effects, chiral effective field theory and lattice calculations. The reported measurements suggest that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements.

Keywords

Systematic Uncertainty Partial Cross Section Constituent Quark Model Lower Wing Pion Cloud 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© SIF, Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • N. Sparveris
    • 1
    Email author
  • S. Stave
    • 2
  • P. Achenbach
    • 3
  • C. Ayerbe Gayoso
    • 3
  • D. Baumann
    • 3
  • J. Bernauer
    • 3
  • A. M. Bernstein
    • 2
  • R. Böhm
    • 3
  • D. Bosnar
    • 6
  • T. Botto
    • 3
  • A. Christopoulou
    • 5
  • D. Dale
    • 7
  • M. Ding
    • 3
  • M. O. Distler
    • 3
  • L. Doria
    • 3
  • J. Friedrich
    • 3
  • A. Karabarbounis
    • 5
  • M. Makek
    • 6
  • H. Merkel
    • 3
  • U. Müller
    • 3
  • I. Nakagawa
    • 4
  • R. Neuhausen
    • 3
  • L. Nungesser
    • 3
  • C. N. Papanicolas
    • 5
  • A. Piegsa
    • 3
  • J. Pochodzalla
    • 3
  • M. Potokar
    • 8
  • M. Seimetz
    • 3
  • S. Širca
    • 8
  • S. Stiliaris
    • 5
  • Th. Walcher
    • 3
  • M. Weis
    • 3
  1. 1.Department of PhysicsTemple UniversityPhiladelphiaUSA
  2. 2.Department of Physics, Laboratory for Nuclear Science and Bates Linear Accelerator CenterMassachusetts Institute of TechnologyCambridgeUSA
  3. 3.Institut für KernphysikJohannes Gutenberg-Universität MainzMainzGermany
  4. 4.Radiation LaboratorySaitamaJapan
  5. 5.Institute of Accelerating Systems and Applications and Department of PhysicsUniversity of AthensAthensGreece
  6. 6.Department of PhysicsUniversity of ZagrebZagrebCroatia
  7. 7.Department of Physics and AstronomyUniversity of KentuckyLexingtonUSA
  8. 8.Institute Jožef StefanUniversity of LjubljanaLjubljanaSlovenia

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