Advertisement

Generalized sum rules of the nucleon in the constituent quark model

  • M. Gorchtein
  • D. Drechsel
  • M. Giannini
  • E. Santopinto
Hadronic resonances

Abstract.

The sum rules serve a powerful tool to study the nucleon structure by providing a bridge between the statical properties of the nucleon (such as electrical charge, and magnetic moment) and the dynamical properties (e.g. the transition amplitudes to excited states) in a wide range of energy and momentum transfer Q 2. We study the generalized sum rules of the nucleon in the framework of the constituent quark model. We use two different CQM, the one with the hypercentral potential [1,2,3], and with the harmonic oscillator potential [4], both with only few parameters fixed to the baryonic spectrum. We confront our results to the model independent sum rules and to the predictions of the phenomenological MAID [5] model and find that in all the cases considered, in the intermediate Q 2 range (0.2-1.5 GeV2), both CQM models provide a good description of the sum rules on the neutron.

PACS codes.

12.39.Jh - Nonrelativistic quark model 14.20.Gk - Baryon resonances and helicity amplitudes 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1. M. Ferraris, M.M. Giannini, M. Pizzo, E. Santopinto, and L. Tiator: PL B 364, 231–238 (1995)CrossRefGoogle Scholar
  2. 2. M. Aiello, M. Ferraris, M.M. Giannini, M. Pizzo, and E. Santopinto: PL B 387, 215-221 (1996)CrossRefGoogle Scholar
  3. 3. M. Aiello, M.M. Giannini, and E. Santopinto: J. Phys. G: Nucl. Part. Phys. 24, 753–762 (1998)CrossRefGoogle Scholar
  4. 4. N. Isgur and G. Karl: Phys. Rev. D 18, 4187Google Scholar
  5. 5. D. Drechsel, O. Hanstein, S. Kamalov, and L. Tiator: Nucl. Phys. A 645, 145 (1999)CrossRefGoogle Scholar
  6. 6. D. Drechsel, B. Pasquini, and M. Vanderhaeghen: Phys. Rept. 378, 99–205 (2003), and references thereinCrossRefGoogle Scholar
  7. 7. J. Ahrens et al. (GDH and A2 Collaboration): Phys. Rev. Lett. 84, 5950 (2000)Google Scholar
  8. 8. A. Airapetian et al. (HERMES Collaboration): hep-ex/ 0210047Google Scholar
  9. 9. M. Amarian et al. (JLab E94010 collaboration): Phys. Rev. Lett. (2002) in pressGoogle Scholar

Copyright information

© Società Italiana di Fisica, Springer-Verlag 2004

Authors and Affiliations

  • M. Gorchtein
    • 1
  • D. Drechsel
    • 2
  • M. Giannini
    • 1
  • E. Santopinto
    • 1
  1. 1.Universit a di Genova, Sezione INFN di Genova, via Dodecaneso 33, 16142 Genova (Italy)
  2. 2.Institut für Kernphysik, Universität Mainz, Staudingerweg 45, 55099 Mainz (Germany)

Personalised recommendations