We report on inclusive hadron production in $e^{+}{e}^{-}$ annihilation at $〈s〉=53\mathrm{}$ Ge${\mathrm{V}}^2$, using a small solid-angle magnetic spectrometer with good particle identification at 90° to the beams at SPEAR II. The cross sections of ${\pi }^{\pm }$ and $K^{\pm }$ when compared with data at $s=23\mathrm{}$ Ge${\mathrm{V}}^2$ exhibit scaling in $\left(\frac{s}{\beta }\right)\frac{d\sigma }{\mathrm{dx}}$ with $x=\frac{2E}{s^{\frac{1}{2}}}$. The invariant cross section depends on the momentum as $p^{-4\mathrm{}}$.

• Received 15 June 1978

DOI:https://doi.org/10.1103/PhysRevLett.41.445