Abstract
We introduce a model independent method for the determination of the hadronic
contribution to the QED running coupling,
\$\Delta\alpha\_HAD(M\_Z^2)\$, requiring no \$e^+e^-\$ annihilation data
as input. This is achieved by calculating the heavy-quark contributions
entirely in perturbative QCD, whilst the light-quark resonance piece is
determined using available lattice QCD results. Future reduction in the current
uncertainties in the latter shall turn this method into a valuable alternative
to the standard approach. Subsequently, we find that the precision of current
determinations of \$\Delta\alpha\_HAD(M\_Z^2)\$ can be improved by
some 20\% by computing the heavy-quark pieces in PQCD, whilst using \$e^+e^-\$
data only for the low-energy light-quark sector. We obtain in this case
\$\Delta\alpha\_HAD(M\_Z^2)=275.7(0.8) 10^-4\$, which
currently is the most precise value of \$\Delta\alpha\_HAD(M\_Z^2)\$.
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