2024 Impact factor 4.8
Particles and Fields
Eur. Phys. J. C 26, 45-49 (2002)
DOI: 10.1140/epjc/s2002-01041-2

Spin structure function g1(x,Q2) and the DHGHY integral I(Q2) at low  Q2: predictions from the GVMD model

B. Badelek1, 2, J. Kwiecinski3 and B. Ziaja3, 4, 5

1  Institute of Experimental Physics, Warsaw University, Hoza 69, 00-681 Warsaw, Poland
2  Department of Physics, Uppsala University, P.O. Box 530, 751 21 Uppsala, Sweden
3  Department of Theoretical Physics, H. Niewodniczanski Institute of Nuclear Physics, Radzikowskiego 152, 31-342 Cracow, Poland
4  Department of Biochemistry, BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
5  High Energy Physics, Uppsala University, P.O. Box 535, 751 21 Uppsala, Sweden


(Received: 9 July 2002 / Published online: 7 October 2002 )

Abstract
Theoretical predictions for the polarized nucleon structure function g1(x,Q2) at low Q2 are obtained in the framework of the generalized vector meson dominance model. Contributions from both light and heavy vector mesons are evaluated. In the photoproduction limit the first moment of g1 is related to the static properties of the nucleon via the Drell-Hearn-Gerasimov-Hosoda-Yamamoto sum rule. This property is employed to fix the magnitude of the light vector meson contribution to g1, using the recent measurements in the region of baryonic resonances. The results are compared to the data on g1(x,Q2). Finally, the DHGHY moment function I(Q2) is calculated, and our theoretical predictions are confronted with the recent preliminary data obtained at the Jefferson Laboratory.



© Società Italiana di Fisica, Springer-Verlag 2002