dorsal/arxiv
View SchemaAxial exchange currents and the spin content of the nucleon
| Authors | D. Barquilla-Cano, A. J. Buchmann, E. Hernandez |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/0303020 |
| URL | https://arxiv.org/abs/nucl-th/0303020 |
Abstract
In a chiral quark model where chiral symmetry is introduced via a non-linear sigma model, we evaluate the axial couplings g_A(0), g_A^8(0) and g_A^0(0 )related to the spin structure of the nucleon. Our calculation includes one-body and two-body axial current and pion absorption operators, which satisfy the Partial Conservation of Axial Current (PCAC) condition. While g_A(0) is dominated by the one-body axial current we find significant corrections due to two-body axial exchange currents in g_A^8(0) and g_A^0(0). Interestingly, the axial current associated with gluon exchange reduces g_A^8(0) from 1 to 0.6. Our analysis shows that the so-called ``proton spin crisis'' can be resolved in a constituent quark model in which PCAC is satisfied. Furthermore, we use the PCAC constraint in order to determine the couplings of the eta and eta' mesons to nucleons.
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"abstract": "In a chiral quark model where chiral symmetry is introduced via a non-linear\nsigma model, we evaluate the axial couplings g_A(0), g_A^8(0) and g_A^0(0\n)related to the spin structure of the nucleon. Our calculation includes\none-body and two-body axial current and pion absorption operators, which\nsatisfy the Partial Conservation of Axial Current (PCAC) condition. While\ng_A(0) is dominated by the one-body axial current we find significant\ncorrections due to two-body axial exchange currents in g_A^8(0) and g_A^0(0).\nInterestingly, the axial current associated with gluon exchange reduces\ng_A^8(0) from 1 to 0.6. Our analysis shows that the so-called ``proton spin\ncrisis\u0027\u0027 can be resolved in a constituent quark model in which PCAC is\nsatisfied. Furthermore, we use the PCAC constraint in order to determine the\ncouplings of the eta and eta\u0027 mesons to nucleons.",
"arxiv_id": "nucl-th/0303020",
"authors": [
"D. Barquilla-Cano",
"A. J. Buchmann",
"E. Hernandez"
],
"categories": [
"nucl-th"
],
"title": "Axial exchange currents and the spin content of the nucleon",
"url": "https://arxiv.org/abs/nucl-th/0303020"
},
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