Single-spin asymmetries at two loops
| Autor: | Benic, Sanjin, Hatta, Yoshitaka, Li, Hsiang-nan, Yang, Dong-Jing |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 100, 094027 (2019) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.100.094027 |
| Popis: | We find a novel mechanism for generating transverse single-spin asymmetry (SSA) in semi-inclusive deep inelastic scattering, distinct from the known ones which involve the Sivers and Collins functions, or their collinear twist-three counterparts. It is demonstrated that a phase needed for SSA can be produced purely within a parton-level cross section starting at two loops. We identify the complete set of two-loop diagrams for SSA, and discuss their gauge invariance and collinear factorization which features the $g_T$ distribution function. In the $k_T$ factorization framework, many more sources for SSA exist, and contributions from all possible two-parton transverse-momentum-dependent parton distribution functions are presented up to two loops and twist three. Comment: 21 pages, 14 figures |
| Databáze: | arXiv |
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