The pion nucleon coupling constant and the Goldberger-Treiman relation
| dc.creator | Bugg, D. V. | |
| dc.creator | Scadron, M. D. | |
| dc.date | 2003-12-25 | |
| dc.date.accessioned | 2026-07-07T03:51:41Z | |
| dc.date.available | 2026-07-07T03:51:41Z | |
| dc.description | The latest $πN$ elastic scattering data are re-analysed to determine the coupling constant $g_c$ of the charged pion, using the dispersion relation for the invariant amplitude $B^{(+)}$. Depending on the choice of data-base, values $g^2_c/4π= 13.80$ to 13.65 are obtained with errors of $\pm 0.12$. We re-examine the well known discrepancy with the Goldberger-Treiman relation. After allowing for the mass dependence of the pion decay constant $f_π$, a (2-3)% discrepancy is predicted, hence $g^2_c/4π= 13.74 \pm 0.10$ in the prior case. The mass difference between charge states of $Δ(1232)$ is $M^0 -M^{++} = 2.0 \pm 0.4$ MeV, close to twice the mass difference between neutron and proton. The difference in widths on resonance is $Γ^0 - Γ^{++} =3.8 \pm 1.0$ MeV. One may account for a width difference of 4.5 MeV from phase space for decays and the extra channel $Δ^0 \to γn$. | |
| dc.description | 15 pages, no figures. Accepted for publication in Euro. Phys. J C | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0312346 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0312346 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/43191 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | The pion nucleon coupling constant and the Goldberger-Treiman relation | |
| dc.type | text |