Evidence for Scaling of Semi-inclusive Cross Sections between 13 and 205 GeV/c

Semi-inclusive invariant cross sections for ${\pi }^{-}$ produced in $\mathrm{pp}$ interactions at 205 GeV/c are compared, at fixed $\frac{n_{-}}{〈n_{-}〉}$, with data at lower energies ranging from 13 to 28.4 GeV/c. Except in the central region ($x\simeq 0$), the data are found to be in good agreement with the predictions of Koba, Nielsen, and Olesen for semi-inclusive scaling.