Orateur
Description
The origin of the large single transverse-spin asymmetries(SSAs) has been a long-standing problem since they were first observed in the pion production and the transversely polarized hyperon production about a half century ago. We currently know two successful pQCD based frameworks in the description of the SSA. One of them is transverse-momentum-dependent(TMD) factorization which is valid when a produced hadron has small transverse momentum compared to the hard scale of a process. The other framework is the twist-3 effect in the collinear factorization which is valid when the transverse momentum is large so that it can be regarded as the hard scale. Although these two frameworks seemingly describe different origins of the SSA, some theoretical work showed that they give the consistent result to the SSA in the intermediate region where both frameworks are valid. This sort of the consistency is important for giving a unified picture to the origin of the SSA. Our group recently has completed the leading-order cross section for the twist-3 fragmentation contributions in the polarized hyperon production in SIDIS. In this talk, we will show our result on the matching between TMD and the twist-3 for this contribution.
