Early Tests of Scale Invariance in High-Energy Muon Scattering

Data are presented on deep inelastic scattering of 56.3- and 150-GeV ${\mu }^{+}$ from an iron target at the Fermi National Acceleratory Laboratory. Observed event rates, averaged over a wide range in $\omega$, are compared to scale-invariance predictions for $q^2$ up to 44 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The ratio of the 150-GeV data to the scale-invariance prediction versus $q^2$ is not constant for all accepted $\omega$ values. A fit of the form ${(1+\frac{g^2}{{\Lambda }^2})}^{-2\mathrm{}}$ yields a lower limit of $\Lambda >10\mathrm{}$ GeV with 90% confidence, averaged over a restricted $\omega$ range.