Abstract
In the covariant quark-diquark model the effective Bethe-Salpeter (BS) equations for the nucleon and the Δ are solved including scalar and axial vector diquark correlations. Their quark substructure is effectively taken into account in both, the interaction kernel of the BS equations and the currents employed to calculate nucleon observables. Electromagnetic current conservation is maintained. The electric form factors of proton and neutron match the data. Their magnetic moments improve considerably by including axial vector diquarks and photon induced scalar-axial vector transitions. The isoscalar magnetic moment can be reproduced, the isovector contribution is about 15% too small. The ratio µG E/G M and the axial and strong couplings g A, g πNN, provide an upper bound on the relative importance of axial vector diquarks confirming that scalar diquarks nevertheless describe the dominant 2-quark correlations inside nucleons.
Similar content being viewed by others
References
H. Leutwyler and J. Stern, Ann. Phys. (N.Y.) 112, 94 (1978).
A. Szczepaniak, C. R. Ji and S. R. Cotanch, Phys. Rev. C 52, 2738 (1995).
P. L. Chung and F. Coester, Phys. Rev. D 44, 229 (1991).
S. Capstick and B. Keister, Phys. Rev. D 51, 3598 (1995).
F. Cardarelli, E. Pace, G. Salme and S. Simula, Phys. Lett. B 357, 267 (1995).
S. Boffi, P. Demetriou, M. Radici and R. F. Wagenbrunn, Phys. Rev. C 60, 025206 (1999).
G. Hellstern, R. Alkofer, M. Oettel and H. Reinhardt, Nucl. Phys. A 627, 679 (1997).
J. C. Bloch et al., Phys. Rev. C 60, 062201 (1999); J. C. Bloch, C. D. Roberts and S. M. Schmidt, Phys. Rev. C 61, 065207 (2000); M. B. Hecht, C. D. Roberts and S. M. Schmidt, nucl-th/0005067.
M. Oettel, M. A. Pichowsky and L. von Smekal, Eur. Phys. J. A 8, 251 (2000).
A. N. Kvinikhidze and B. Blankleider, Phys. Rev. C 60 (1999) 044003; 044004.
N. Ishii, e-print, nucl-th/0004063.
K. Kusaka, G. Piller, A. W. Thomas and A. G. Williams, Phys. Rev. D 55, 5299 (1997).
M. Oettel, G. Hellstern, R. Alkofer and H. Reinhardt, Phys. Rev. C 58, 2459 (1998).
M. Oettel and R. Alkofer, Phys. Lett. B 484, 243 (2000).
A. Bender, C. D. Roberts and L. v. Smekal, Phys. Lett. B 380, 7 (1996).
P. Maris, C. D. Roberts and P. C. Tandy, Phys. Lett. B 420, 267 (1998).
P. Maris and C. D. Roberts, Phys. Rev. C 56, 3369 (1997).
R. Delbourgo and M. D. Scadron, J. Phys. G 5, 1621 (1979).
S. Kopecky, P. Riehs, J. A. Harvey and N. W. Hill, Phys. Rev. Lett. 74, 2427 (1995).
G. Hoehler et al., Nucl. Phys. B 114, 505 (1976).
S. Platchkov et al., Nucl. Phys. A 510, 740 (1990).
I. Passchier et al., Phys. Rev. Lett. 82, 4988 (1999).
M. Ostrick et al., Phys. Rev. Lett. 83, 276 (1999).
M. K. Jones et al. [Jefferson Lab Hall A Collaboration], Phys. Rev. Lett. 84, 1398 (2000).
R. A. Arndt, R. L. Workman and M. M. Pavan, Phys. Rev. C 49, 2729 (1994).
J. Rahm et al., Phys. Rev. C 57, 1077 (1998).
C. Caso et al., Review of Particle Physics, Eur. Phys. J. C 3, 1 (1998).
T. Kitagaki et al., Phys. Rev. D 42, 1331 (1990).
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by W. Weise
Rights and permissions
About this article
Cite this article
Oettel, M., Alkofer, R. & von Smekal, L. Nucleon properties in the covariant quark-diquark model. Eur. Phys. J. A 8, 553–566 (2000). https://doi.org/10.1007/s100500070078
Received:
Issue Date:
DOI: https://doi.org/10.1007/s100500070078