2006/12/31 by Y. Koike, Yuji Koike, Kazuhiro Tanaka · 60 citations
Physics and Astronomy · #Asymmetry #Deep inelastic scattering #Gluon #High-Energy Particle Collisions Research #Inelastic scattering #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum electrodynamics #Quantum mechanics #Quark #Scattering #Spin (aerodynamics) #Transverse plane #Twist #hep-ph
paper · pdf · open access · doi:10.1016/j.physletb.2007.01.044
published in Physics Letters B 646(5-6), 232-241 (Elsevier BV) · 20 pages, 6 figures; [v2] a paragraph with new Eq. (30) added, minor modifications, typos corrected; [v3] Erratum added, and minor changes
openalex publication_date 2007/02/09 · arxiv created 2008/09/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Perturbative QCD relates the single transverse-spin asymmetries (SSAs) for hard processes at large transverse-momentum of produced particle to partonic matrix elements that describe interference between scattering from a coherent quark–gluon pair and from a single quark, generated through twist-3 quark–gluon correlations inside a hadron. When the coherent gluon is soft at the gluonic poles, its coupling to partonic subprocess can be systematically disentangled, so that the relevant interfering amplitude can be derived entirely from the Born diagrams for the scattering from a single quark. We establish a new formula that represents the exact rules to derive the SSA due to soft-gluon poles from the knowledge of the twist-2 cross-section formula for unpolarized processes. This single master formula is applicable to a range of processes like Drell–Yan and direct-photon production, and semi-inclusive deep inelastic scattering, and is also useful to manifest the gauge invariance of the results.