2000/05/14 by J. Soffer, J Soffer, O. V. Teryaev +1 · 3 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1016/s0370-2693(00)00972-2
published as Phys.Lett.B490:106-110,2000 · 11 pages, 2 figures
arxiv created 2000/05/14 · openalex publication_date 2000/09/01 · arxiv updated 2011/02/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29
The positivity bound for the transverse asymmetry A2 may be improved and applied for each quark flavor separately. We use it to test the consistency of twist-two approximation for the transverse spin-dependent (gT) and the longitudinal spin-averaged (FL) structure functions. While it is satisfied in the case of u quarks, it might be violated for d quarks in a region of moderate x because of its negative polarization. We attribute this inconsistency to a stronger twist-three contribution, whose existence found by the QCD sum rule method is a long-standing puzzle.