The average squared transverse energy of jets in deep-inelastic muon-nucleon scattering is measured as a function of the momentum transfer squared (${\mathit{Q}}^2$), in the range 3<${\mathit{Q}}^2$<25 ${\mathrm{GeV}}^2$. Perturbative QCD predicts that the average squared parton transverse energy will depend upon the strong coupling constant (${\mathrm{\alpha }}_{\mathit{S}}$). Identifying the transverse energy of the jets with those of the corresponding partons, ${\mathrm{\alpha }}_{\mathit{S}}$ is found to vary with ${\mathit{Q}}^2$ as predicted by QCD.

• Received 6 July 1993

DOI:https://doi.org/10.1103/PhysRevLett.72.466