Inclusiveπ0Production inppCollisions at 50-400 GeV/c

We have measured the single-photon cross section in the reaction $p+p\to \gamma +\mathrm{anything}$ for incident proton momenta from 50 to 400 GeV/c and lab angles of 80, 100, and 120 mrad. It is shown that in the range $p_{\perp }=0.3\mathrm{} \mathrm{to} 4.3$ GeV/c, the derived ${\pi }^0$ invariant cross section can be factorized into a product of two functions, one in $p_{\perp }$ and the other in a new scaling variable $x_R=\frac{p^{*}}{{p_{max}}^{*}}$, where $p^{*}$ is the total c.m. momentum of the ${\pi }^0$.