2000/05/31 by Olivier Martin, O. Martin, Martin, O. +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0005320
21 pages, 10 figures
arxiv created 2000/05/31 · openalex publication_date 2000/05/31 · arxiv updated 2009/11/30 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
We compare theoretical results for jet and prompt photon production in polarized pp-collisions at RHIC obained with three different methods: a) the unpolarized event generator PYTHIA combined with hadronic asymmetry weights calculated from leading order formulae, b) the polarized event generator SPHINX which treats the partonic helicity in the hard scattering and the initial state shower explicitly, and c) parton generators which integrate next-to-leading order QCD cross sections using Monte Carlo methods. Method a) requires far less computer time than method b) but we find that it is too imprecise for precision studies. The lacking treatment of partonic polarization in the initial state shower results in relative deviations in the asymmetries of up to 20% relative to SPHINX (method b)). As was to be expected, the event generator predictions for the absolute cross sections differ significantly from the next-to-leading order QCD calculations. But fortunately the asymmetries show a much better agreement: relative deviations for prompt photon production for parameterizations with medium and large Δg(x,μ2) barely exceed 10%. After fine tuning the parameters of the parton showers the same result can be obtained for jet production.