Azimuthal asymmetries at HERA: theoretical aspects

Abstract

We comment on theoretical aspects of the measurement of azimuthal asymmetries in semi-inclusive charged particle production, made recently by the ZEUS Collaboration at HERA. By taking the ratio of the two measured asymmetries, we find good agreement between the perturbative QCD prediction and the experimental data. To separate the perturbative and nonperturbative contributions to the asymmetries, we suggest that the azimuthal asymmetries of the transverse energy flow be measured as a function of a variable $q_T$ related to the pseudorapidity of the energy flow.

Final version: 11 pages, 2 figures

References in corpus (3)

• Fragmentation Functions for Pions, Kaons, and Protons at Next-to-Leading Order
• Fragmentation Functions from Flavour-inclusive and Flavour-tagged e^+e^- Annihilations
• Measurement of Azimuthal Asymmetries in Deep Inelastic Scattering

Cited by in corpus (8)

• Drell-Yan Lepton Angular Distribution at Small Transverse Momentum
• Phenomenology of multiple parton radiation in semi-inclusive deep-inelastic scattering
• Resummation for Polarized Semi-Inclusive Deep-Inelastic Scattering at Small Transverse Momentum
• Twist-4 contributions to the azimuthal asymmetry in SIDIS
• Transverse momentum dependence of the angular distribution of the Drell-Yan process
• Azimuthal asymmetries in semi-inclusive DIS with polarized beam and/or target and their nuclear dependences
• Crossed Threshold Resummation
• Measurement of azimuthal asymmetries in neutral current deep inelastic scattering at HERA