https://doi.org/10.1140/epja/s10050-023-01066-9
Regular Article - Theoretical Physics
-Baryon axialvector and pseudoscalar form factors, and associated PCAC relations
1
College of Science, Nanjing University of Posts and Telecommunications, 210023, Nanjing, China
2
Interdisciplinary Center for Theoretical Study, University of Science and Technology of China, 230026, Hefei, Anhui, China
3
Peng Huanwu Center for Fundamental Theory, 230026, Hefei, Anhui, China
4
Institut für Theoretische Physik, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany
5
Helmholtz Forschungsakademie Hessen für FAIR (HFHF), GSI Helmholtzzentrum für Schwerionenforschung, Campus Gießen, 35392, Gießen, Germany
6
School of Physics, Nanjing University, 210093, Nanjing, Jiangsu, China
7
Institute for Nonperturbative Physics, Nanjing University, 210093, Nanjing, Jiangsu, China
b
chenchen1031@ustc.edu.cn
d
cdroberts@nju.edu.cn
Received:
18
May
2023
Accepted:
23
June
2023
Published online:
18
July
2023
A quark + diquark Faddeev equation treatment of the baryon bound state problem in Poincaré-invariant quantum field theory is used to deliver parameter-free predictions for all six -baryon elastic weak form factors. Amongst the results, it is worth highlighting that there are two distinct classes of such
-baryon form factors,
,
, the functions within each of which are separately linked via partial conservation of axial current (PCAC) and Goldberger-Treiman (GT) relations. Respectively within each class, the listed form factors possess qualitatively the same structural features as the nucleon axial, induced pseudoscalar, and pion-nucleon coupling form factors. For instance, the
-baryon
axial form factor can reliably be approximated by a dipole function, characterised by an axial charge
and mass-scale
. Moreover, the two distinct
-baryon PCAC form factor relations are satisfied to a high degree of accuracy on a large range of
; the associated GT relations present good approximations only on
; and pion pole dominance approximations are reliable within both classes. There are two
couplings:
;
; and the associated form factors are soft. Such couplings commonly arise in phenomenology, which may therefore benefit from our analyses. A flavour decomposition of the axial charges reveals that quarks carry 71% of the
-baryon spin. The analogous result for the proton is
%.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.