Calculating the pion decay constant from α_s(M_Z)
| dc.creator | Hashimoto, Michio | |
| dc.creator | Tanabashi, Masaharu | |
| dc.date | 2002-10-08 | |
| dc.date.accessioned | 2026-07-07T03:48:11Z | |
| dc.date.available | 2026-07-07T03:48:11Z | |
| dc.description | We revisit the analysis of the improved ladder Schwinger-Dyson (SD) equation for the dynamical chiral symmetry breaking in QCD with emphasizing the importance of the scale ambiguity. Previous calculation done so far naively used one-loop MSbar coupling in the improved ladder SD equation without examining the scale ambiguity. As a result, the calculated pion decay constant f_πwas less than a half of its experimental value f_π=92.4MeV once the QCD scale is fixed from the high energy coupling α_s(M_Z). In order to settle the ambiguity in a proper manner, we adopt here in the present paper the next-to-leading-order effective coupling instead of a naive use of the MSbar coupling. The pion decay constant f_πis then calculated from high energy QCD coupling strength α_s(M_Z)=0.1172 \pm 0.0020. Within the Higashijima-Miransky approximation, we obtain f_π=85--106MeV depending on the value of α_s(M_Z) which agrees well with the experimentally observed value f_π=92.4MeV. The validity of the improved ladder SD equation is therefore ascertained more firmly than considered before. | |
| dc.description | 14pages, 10figures, revtex4 | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0210115 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0210115 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/41908 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.subject | Nuclear Theory | |
| dc.title | Calculating the pion decay constant from α_s(M_Z) | |
| dc.type | text |