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The E2/M1 Mixing Ratio in the Excitation of the Δ from Polarized Photo-Reactions

  • A. M. Sandorfi
  • G. Blanpied
  • M. Blecher
  • A. Caracappa
  • C. Djalali
  • G. Giordano
  • K. Hicks
  • S. Hoblit
  • M. A. Khandaker
  • O. C. Kistner
  • G. Matone
  • L. Miceli
  • B. M. Preedom
  • D. Rebreyend
  • C. Schaerf
  • R. M. Sealock
  • H. Ströher
  • A. Tam
  • C. E. Thorn
  • S. T. Thornton
  • C. S. Whisnant
  • X. Zhao
Part of the Few-Body Systems book series (FEWBODY, volume 7)

Abstract

In constituent quark models, a tensor interaction, mixing quark spins with their relative motion, is introduced to reproduce the observed baryon spectrum. This has a consequence completely analogous to the nuclear tensor force between the n and p in deuterium. A D state component is mixed into what would otherwise be a purely S-wave object. The D-wave component breaks spherical symmetry, resulting in a non-vanishing <r2Y2> matrix element for the nucleon and a static quadrupole moment and deformation for its first excited state, the Δ resonance, at ∽325 MeV. The magnitude and sign of this D-state component are quite sensitive to the internal structure of the proton and have been of great interest in recent years [1].

Keywords

Compton Scattering Cross Section Ratio Tensor Interaction National Synchrotron Light Source Unpolarized Cross Section 
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

© Springer-Verlag/Wien 1994

Authors and Affiliations

  • A. M. Sandorfi
    • 1
  • G. Blanpied
    • 5
  • M. Blecher
    • 7
  • A. Caracappa
    • 1
  • C. Djalali
    • 5
  • G. Giordano
    • 2
  • K. Hicks
    • 8
  • S. Hoblit
    • 6
  • M. A. Khandaker
    • 7
  • O. C. Kistner
    • 1
  • G. Matone
    • 2
  • L. Miceli
    • 1
  • B. M. Preedom
    • 5
  • D. Rebreyend
    • 5
  • C. Schaerf
    • 3
    • 4
  • R. M. Sealock
    • 6
  • H. Ströher
    • 9
  • A. Tam
    • 5
  • C. E. Thorn
    • 1
  • S. T. Thornton
    • 6
  • C. S. Whisnant
    • 5
  • X. Zhao
    • 7
  1. 1.Physics DepartmentBrookhaven National LaboratoryUptonUSA
  2. 2.INFN-Laboratori Nazionali di FrascatiFrascatiItaly
  3. 3.Universita di RomaRomeItaly
  4. 4.INFN-Sezione di RomaRomeItaly
  5. 5.Department of PhysicsUniversity of South CarolinaColumbiaUSA
  6. 6.Department of PhysicsUniversity of VirginiaCharlottesvilleUSA
  7. 7.Physics DepartmentVirginia Polytechnic Institute & SUBlacksburgUSA
  8. 8.Department of PhysicsOhio UniversityAthensUSA
  9. 9.II Physikalisches InstitutUniversität GießenGießenGermany

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