QUANTUM-CHROMODYNAMIC GLUON CONTRIBUTIONS TO LARGE-PT REACTIONS

We use a calculation based on the lowest order in the perturbation series for quantum chromodynamics to obtain an estimate for the contribution of hard-scattering processes involving vector gluons to the production of hadrons at large transverse momentum. Some simple models for the distribution of gluons in a proton and for the distribution of hadrons within a hard gluon jet are presented and used to calculate the process pp→π0X. At s=53 GeV we find that the contribution of the subprocess qV→qV is comparable to that of qq→qq. The resulting cross sections are rather close to the CERN ISR data in magnitude. It is possible that small corrections arising, for example, from higher-order terms in the perturbation expansion might lead to a detailed fit to these data. At higher energies, such as those to be obtained in proposed new experimental facilities, our results indicate that the mechanisms VV→VV and qV→qV may dominate over qq→qq in much of the accessible kinematic regime. We briefly consider some experimental consequences of possible gluon dominance. © 1978 The American Physical Society.