Sivers and collins effects: From SIDIS to proton-proton inclusive pion production

We consider the Sivers, Collins and transversity functions as extracted from SIDIS and e ⁺ e- experimental data and investigate to what extent they might explain the large Single Spin Asymmetries (SSA) observed in proton-proton inclusive processes. This phenomenological study is performed within the TMD factorization scheme. As the SIDIS data cover only a limited range of x values (x ≲ 0.3), we allow for different large x behaviours of the SIDIS Sivers functions and transversity distributions. We conclude that, within the available experimental constraints, one cannot observe any clear universality breaking effect for the Sivers functions.