Skip to main content
SpringerLink
Log in

Electromagnetic form factors of the \(\Delta(1232)\) excitation

  • Original Paper
  • Published:
The European Physical Journal A - Hadrons and Nuclei Aims and scope Submit manuscript

Abstract.

In the resonance region we have precisely determined the electromagnetic properties of the \(\Delta(1232)\)-resonance, in particular the E2/M1 ratio \(R_{EM}=(-2.5 \pm 0.1) \%\). For pion electroproduction recent experimental data from Mainz, Bates, Bonn and JLab for Q2 up to 4.0 (GeV/c)2 have been analyzed with the isobar model MAID. The extracted E2/M1 ratio shows, starting from a small and negative value at the real photon point, a clear tendency to cross zero, and becomes positive with increasing Q2. This is a possible indication of a very slow approach toward the pQCD region. The C2/M1 ratio near the photon point is found as \(R_{SM}(0)=(-6.5 \pm 0.5) \%\). At high Q2, the absolute value of the ratio is strongly increasing, a further indication that pQCD is not yet reached. The electromagnetic-transition form factors of the \(\Delta(1232)\) excitation are parameterized and fitted to the electroproduction data. This also shows a zero-crossing of the electric form factor G E * at \(Q^2=3.6\pm 0.5\) (GeV/c)2.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. C.M. Becchi, G. Morpurgo, Phys. Lett. 17, 352 (1965).

    Article  Google Scholar 

  2. R. Koniuk, N. Isgur, Phys. Rev. D 21, 1868 (1980).

    Article  Google Scholar 

  3. S.S. Gershteyn, G.V. Dzhikiya, Sov. J. Nucl. Phys. 34, 870 (1981).

    Google Scholar 

  4. N. Isgur, G. Karl, R. Koniuk, Phys. Rev. D 25, 2394 (1982).

    Article  Google Scholar 

  5. A.J. Buchmann, E. Hernandez, A. Faessler, Phys. Rev. C 55, 448 (1997).

    Article  Google Scholar 

  6. A.J. Buchmann, E.M. Henley, Phys. Rev. C 63, 015202 (2000).

    Article  Google Scholar 

  7. D. Drechsel, M.M. Giannini, Phys. Lett. B 143, 329 (1984).

    Article  Google Scholar 

  8. S. Capstick, G. Karl, Phys. Rev. D 41, 2767 (1990).

    Article  Google Scholar 

  9. S. Capstick, Phys. Rev. D 46, 2864 (1992).

    Article  Google Scholar 

  10. K. Bermuth, D. Drechsel, L. Tiator, J.B. Seaborn, Phys. Rev. D 37, 89 (1988).

    Article  Google Scholar 

  11. D.H. Lu, A.W. Thomas, A.G. Williams, Phys. Rev. C 57, 2628 (1998).

    Article  Google Scholar 

  12. A. Wirzba, W. Weise, Phys. Lett. B 188, 6 (1987).

    Article  Google Scholar 

  13. G.C. Gellas, T.R. Hemmert, C.N. Ktorides, G.I. Poulis, Phys. Rev. D 60, 054022 (1999).

    Article  Google Scholar 

  14. D.B. Leinweber, T. Draper, R. Woloshyn, in Baryons '92, Proceedings of the International Conference on the Structure of Baryons and Related Mesons, Yale University, 1992, edited by Moshe Gai (World Scientific, Singapore, 1993) p. 29.

  15. C. Alexandrou , hep-lat/0209074.

  16. G. Blanpied , Phys. Rev. C 64, 025203 (2001).

    Article  Google Scholar 

  17. R. Beck , Phys. Rev. Lett. 78, 606 (1997).

    Article  Google Scholar 

  18. R. Beck , Phys. Rev. C 61, 035204 (2000).

    Article  Google Scholar 

  19. O. Hanstein, D. Drechsel, L. Tiator, Nucl. Phys. A 632, 561 (1998).

    Article  Google Scholar 

  20. R.A. Arndt, W.J. Briscoe, I.I. Strakovsky, R.L. Workman, nucl-th/0205067.

  21. K. Hagiwara (Particle Data Group), Phys. Rev. D 66, 010001 (2002).

    Article  Google Scholar 

  22. S.J. Brodsky, G.P. Lepage, Phys. Rev. D 23, 1152 (1981)

    Article  Google Scholar 

  23. R.M. Davidson , Phys. Rev. C 59, 1059 (1999).

    Article  Google Scholar 

  24. Baryon Resonance Analysis Group (BRAG), http://cnr2.kent.edu/ manley/BRAG.html.

  25. R.A. Arndt (BRAG working group), Proceedings of NSTAR2001 Workshop, Mainz 2001, edited by D. Drechsel, L. Tiator (World Scientific, Singapore, 2001) p. 467.

  26. S.N. Yang, J. Phys. G 11 (1985) L205.

    Google Scholar 

  27. R.A. Arndt, I.I. Strakovsky, R.L. Workman, Phys. Rev. C 56, 577 (1997).

    Article  Google Scholar 

  28. D. Drechsel, O. Hanstein, S.S. Kamalov, L. Tiator, Nucl. Phys. A 645, 145 (1999)

    Article  Google Scholar 

  29. S.S. Kamalov, S.N. Yang, Phys. Rev. Lett. 83, 4494 (1999).

    Article  Google Scholar 

  30. R.A. Arndt, R.L. Workman, Z. Li, L.D. Roper, Phys. Rev. C 42, 1864 (1990).

    Article  Google Scholar 

  31. Th. Pospischil , Phys. Rev. Lett. 86, 2959 (2001).

    Article  Google Scholar 

  32. C. Mertz , Phys. Rev. Lett. 86, 2963 (2001).

    Article  Google Scholar 

  33. T. Bantes, R. Gothe, private communication.

  34. G. Laveissiere , Proceedings of NSTAR2001 Workshop, Mainz 2001, edited by D. Drechsel, L. Tiator (World Scientific, 2001) p. 271.

  35. K. Joo , Phys. Rev. Lett. 88, 122001-1 (2002).

    Article  Google Scholar 

  36. V.V. Frolov , Phys. Rev. Lett. 82, 45 (1999).

    Article  Google Scholar 

  37. S. Kamalov, S.N. Yang, D. Drechsel, O. Hanstein, L. Tiator, Phys. Rev. C 64, 032201 (2001).

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Institut für Kernphysik, Universtät Mainz, D-55099, Mainz, Germany

    L. Tiator & D. Drechsel

  2. Institut für Kernphysik, JINR Dubna, 141980, Moscow Region, Russia

    S.S. Kamalov

  3. Department of Physics, National Taiwan University, 10617, Taipei, Taiwan

    S.N. Yang

Authors
  1. L. Tiator
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. D. Drechsel
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. S.S. Kamalov
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. S.N. Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to L. Tiator.

Additional information

Received: 1 November 2002, Published online: 15 July 2003

PACS:

13.40.Gp Electromagnetic form factors - 13.60.Le Meson production - 14.20.Gk Baryon resonances with S=0 - 25.20.Lj Photoproduction reactions

Rights and permissions

Reprints and permissions

About this article

Cite this article

Tiator, L., Drechsel, D., Kamalov, S. et al. Electromagnetic form factors of the \(\Delta(1232)\) excitation. Eur. Phys. J. A 17, 357–363 (2003). https://doi.org/10.1140/epja/i2002-10177-6

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1140/epja/i2002-10177-6

Keywords

Search

Navigation