| Autor: |
Chen Chen, Christian S. Fischer, Craig D. Roberts, Jorge Segovia |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Physics Letters B, Vol 815, Iss , Pp 136150- (2021) |
| Druh dokumentu: |
article |
| ISSN: |
0370-2693 |
| DOI: |
10.1016/j.physletb.2021.136150 |
| Popis: |
A symmetry-preserving Poincaré-covariant quark+diquark Faddeev equation treatment of the nucleon is used to deliver parameter-free predictions for the nucleon's axial and induced pseudoscalar form factors, GA and GP, respectively. The result for GA can reliably be represented by a dipole form factor characterised by an axial charge gA=GA(0)=1.25(3) and a mass-scale MA=1.23(3)mN, where mN is the nucleon mass; and regarding GP, the induced pseudoscalar charge gp⁎=8.80(23), the ratio gp⁎/gA=7.04(22), and the pion pole dominance Ansatz is found to provide a reliable estimate of the directly computed result. The ratio of flavour-separated quark axial charges is also calculated: gAd/gAu=−0.16(2). This value expresses a marked suppression of the size of the d-quark component relative to that found in nonrelativistic quark models and owes to the presence of strong diquark correlations in the nucleon Faddeev wave function – both scalar and axial-vector, with the scalar diquark being dominant. The predicted form for GA should provide a sound foundation for analyses of the neutrino-nucleus and antineutrino-nucleus cross-sections that are relevant to modern accelerator neutrino experiments. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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