Nucleon Spin Structure Functions in the Effective Chiral Quark Theory

Chun-Khiang Chua；W-Y. P. Hwang

Chinese Journal of Physics

36卷4期（1998 / 08 / 01）

588 - 605

英文

We show that the nucleon spin structure functions, as extracted from the recent experiments carried out by the European Muon Collaboration (EMC), the SLAC El43 Collaboration, and the Spin Muon Collaboration (SMC), can be understood quantitatively in the context of the effective chiral quark theory, both for the measured first moment Гl =∫o^1 g1(x)dx and the functional form (or the shape) of the spin structure function g1(x) ( as a function of the Bjorken scaling variable x). The surprising success suggests strongly that the nonperturbative effects due to Goldstone bosons play a significant role, and should be taken into account, in the kinematic range of the momentum transferred squared Q^2 of a few GeV^2. The relation to the meson-baryon picture, now recognized as ”generalized Sullivan processes”, is briefly discussed.