Axial exchange currents and the spin content of the nucleon in a nonrelativistic chiral quark model

作者：Barquilla Cano D; Buchmann AJ; Hernandez E^*

来源：Nuclear Physics A, 2003, 721: 429C-432C.

DOI：10.1016/S0375-9474(03)01089-3

Within the context of a nonrelativistic chiral quark model (chiQM) where chiral symmetry is introduced via a non-linear sigma model, we evaluate the axial form factors g(A)(3)(0), g(A)(8)(0) and g(A)(0)(0) related to the quark spin content of the nucleon. Our calculation A A A includes one-body (impulse approximation) and two-body (exchange currents) axial operators whose contributions satisfy Partial Conservation of Axial Current (PCAC) exactly. While g(A)(3)(0) is dominated by the impulse contribution we find significant corrections due to exchange currents effects in the evaluation of the other two quantities, 9(A)(8)(0) and g(A)(0)(0). The results are in good agreement with experiment. In addition, the use of PCAC allows us to obtain couplings constants of the eta and eta' mesons to nucleons that are in good agreement with other determinations.

• 出版日期2003-6-30