2001/07/02 by Michael Klasen, M. Klasen · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1088/0954-3899/28/5/329
published as J.Phys.G28:1091-1102,2002 · Talk presented at the Ringberg Workshop on ``New Trends in HERA Physics 2001''. 12 pages, 10 postscript figures
arxiv created 2001/07/02 · openalex publication_date 2002/04/18 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
Despite its theoretical and practical importance, the pion structure is still badly constrained, particularly at low x π and in the sea-quark and gluon sectors. Recently, ZEUS have presented data on dijet photoproduction with a leading neutron, which is dominated by slightly off-shell pion exchange and can be used to constrain the pion densities down to x π ≃ 0.01. We compare a recent next-to-leading order calculation to the ZEUS data and find that the lower gluon densities of SMRS seem to be preferred by the data. Theoretical uncertainties, in particular from the pion flux, are discussed in some detail.