Improved Determination of $α(M_{\rm Z}^2$) and the Anomalous Magnetic Moment of the Muon

dc.creatorDavier, Michel
dc.creatorHoecker, Andreas
dc.date1998-01-20
dc.date.accessioned2026-07-07T11:09:44Z
dc.date.available2026-07-07T11:09:44Z
dc.descriptionWe reevaluate the hadronic contribution to the running of the QED fine structure constant \aqed at $s=M_{\rm Z}^2$. We use data from \ee\ annihilation and $τ$ decays at low energy and at the $q\bar{q}$ thresholds, where resonances occur. Using so-called spectral moments and the Operator Product Expansion (OPE), it is shown that a reliable theoretical prediction of the hadronic production rate $R(s)$ is available at relatively low energies. Its application improves significantly the precision on the hadronic vacuum polarization contribution. We obtain \daqedhZ $=(277.8\pm2.6)\times10^{-4}$ yielding $α^{-1}(M_{\rm Z}^2)=128.923\pm0.036$. Inserting this value in a global electroweak fit using current experimental input, we constrain the mass of the Standard Model Higgs boson to be $M_{\rm Higgs}=129^{+103}_{-62}~{\rm GeV}$. Analogously, we improve the precision of the hadronic contribution to the anomalous magnetic moment of the muon for which we obtain $a_μ^{\rm had}=(695.1\pm7.5)\times 10^{-10}$.
dc.description18 pages
dc.identifierhttps://arxiv.org/abs/hep-ph/9801361
dc.identifierhttp://arxiv.org/abs/hep-ph/9801361
dc.identifierPhys.Lett.B419:419-431,1998
dc.identifierdoi:10.1016/S0370-2693(97)01512-8
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/190571
dc.subjectHigh Energy Physics - Phenomenology
dc.titleImproved Determination of $α(M_{\rm Z}^2$) and the Anomalous Magnetic Moment of the Muon
dc.typetext

Files

Collections