arXiv:1112.4423·v3·High Energy Physics — Phenomenology
Calculation of TMD Evolution for Transverse Single Spin Asymmetry Measurements
S. Mert Aybat🇳🇱 · Alexei Prokudin🇺🇸 · Ted C. Rogers🇺🇸
Abstract
The Sivers transverse single spin asymmetry (TSSA) is calculated and compared at different scales using the TMD evolution equations applied to previously existing extractions. We apply the Collins-Soper-Sterman (CSS) formalism, using the version recently developed by Collins. Our calculations rely on the universality properties of TMD-functions that follow from the TMD-factorization theorem. Accordingly, the non-perturbative input is fixed by earlier experimental measurements, including both polarized semi-inclusive deep inelastic scattering (SIDIS) and unpolarized Drell-Yan (DY) scattering. It is shown that recent COMPASS measurements are consistent with the suppression prescribed by TMD evolution.
Comments: 4 pages, 2 figures. Version published in Physical Review Letters