2009/09/30 by U. D’Alesio, U. D'Alesio, Elliot Leader +2
Physics and Astronomy · #Black Holes and Theoretical Physics #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.81.036010
published as Phys.Rev.D81:036010,2010 · RevTeX4, 17 pages, 7 eps figures
arxiv created 2009/09/30 · openalex publication_date 2010/02/17 · arxiv updated 2010/04/06 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We show that respecting the underlying Lorentz structure in the parton model has very strong consequences. Failure to insist on the correct Lorentz covariance is responsible for the existence of contradictory results in the literature for the polarized structure function g2(x), whereas with the correct imposition we are able to derive the Wandzura-Wilczek relation for g2(x) and the target-mass corrections for polarized deep inelastic scattering without recourse to the operator product expansion. We comment briefly on the problem of threshold behavior in the presence of target-mass corrections. Careful attention to the Lorentz structure has also profound implications for the structure of the transverse momentum dependent parton densities often used in parton model treatments of hadron production, allowing the \mathbitkT dependence to be derived explicitly. It also leads to stronger positivity and Soffer-type bounds than usually utilized for the collinear densities.