Early Tests of Scale Invariance in High-Energy Muon Scattering

Data are presented on deep inelastic scattering of 56.3- and 150-GeV ${\ensuremath{\mu}}^{+}$ from an iron target at the Fermi National Acceleratory Laboratory. Observed event rates, averaged over a wide range in $\ensuremath{\omega}$, 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 $\ensuremath{\omega}$ values. A fit of the form ${(1+\frac{{g}^{2}}{{\ensuremath{\Lambda}}^{2}})}^{\ensuremath{-}2}$ yields a lower limit of $\ensuremath{\Lambda}>10$ GeV with 90% confidence, averaged over a restricted $\ensuremath{\omega}$ range.