One-gluon-exchange quark scattering and large-pTinclusive data

Abstract

Calculations based on the idea of asymptotic freedom enable one to estimate an effective quark-gluon coupling from experimental observations of scaling violations in deep-inelastic scattering, from Okubo-Zweig-Iizuka-rule-forbidden decays of the $\psi$ and the ${\psi }^{\prime }$ and from corrections to the parton model for $\sigma$($e^{+}{e}^{-}\to \mathrm{hadrons}$). These estimates then make it possible to normalize the one-gluon-exchange Born term for quark-quark elastic scattering and, within the context of hard-scattering models for hadronic collisions, obtain a lower limit on large-$p_T$ inclusive cross sections. The theoretical lower limit for the cross section is found to be slightly below CERN ISR data on $\mathrm{pp}\to {\pi }^{0}X$ at $\sqrt{s}=53\mathrm{}$ GeV, $p_T\ge 6$ GeV. Further measurements at the CERN ISR or at projected new accelerators may be sensitive to the presence of this mechanism. Such measurements will be extremely important in testing the underlying unity of diverse reactions within the general framework of quark-gluon dynamics. They may also provide the most direct determination of the effective hadronic coupling constant.