Test of Scale Invariance in Ratios of Muon Scattering Cross Sections at 150 and 56 GeV

Scale invariance is tested in ratios of muon scattering cross sections from an iron target at pairs of $q^2$ values ranging to 40 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ and differing by a factor of $\frac{3}{8}$. The apparatus was changed with incident energy to preserve acceptance and resolution in scaled variables. The scale-noninvariant departure from unity of these ratios displays a statistically significant $\omega$ dependence. The effect exceeds the systematic uncertainty by a factor of 1.7.