2009/01/31 by H. G. Cao, Cao Hui-Geng, J. P. Ma +3 · 20 citations
Mathematics · Physics and Astronomy · #Asymmetry #Factorization #Hadron #Helicity #High-Energy Particle Collisions Research #Massless particle #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Parton #Physics #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1088/0253-6102/53/2/21
published in Communications in Theoretical Physics 53(2), 313-324 (Institute of Physics) · shortened version to match published version
arxiv created 2009/12/15 · openalex publication_date 2010/02/01 · arxiv updated 2014/11/18 · openalex created_date 2019/12/26 · openalex updated_date 2026/08/06
Two factorization approaches have been proposed for single transverse spin asymmetries. One is the collinear factorization, the other is the transverse-momentum-dependent factorization. They have been previously derived in a formal way by using diagram expansion at hadron level. If the two factorizations hold or can be proven, they should also hold when we replace hadrons with parton states. We examine these two factorizations at parton level with massless partons. It is nontrivial to generate these asymmetries at parton level with massless partons because the asymmetries require helicity-flip and nonzero absorptive parts in scattering amplitudes. By constructing suitable parton states with massless partons we derive the two factorizations for the asymmetry in Drell–Yan processes. It is found from our results that the collinear factorization derived at parton level is not the same as that derived at hadron level. Our results with massless partons confirm those derived with single massive parton state in our previous works.