Speaker
Description
The analysis of single transverse-spin asymmetries (SSAs) gives us tremendous insight into the internal structure of hadrons. For example, the Sivers and Collins effects in semi-inclusive deep-inelastic scattering (SIDIS), Sivers effect in Drell-Yan, and the Collins effect in electron-positron annihilation have been widely investigated over many years in order to perform 3D momentum-space tomography. In addition, observables like $A_N$ in proton-proton collisions are of interest due to their sensitivity to quark-gluon correlations. In this talk I will report on the first global fit of SSA data from SIDIS, Drell-Yan, $e^+e^−$ annihilation into hadron pairs, and proton-proton collisions. I will discuss the results of our analysis, including the extraction of a unique set of universal non-perturbative functions that describe all observed SSAs, and also explore avenues for future research.