Overview of the collinear twist-3 factorization for spin asymmetries

28 Apr 2015, 09:25


WG6 Spin Physics WG6 Spin Physics


Prof. Yuji Koike (Niigata University)


In this talk, I will present an overview on the current status of the analyses of the spin asymmetries, in particular, single spin asymmetries, using the framework of the collinear twist-3 (CT3) factorization. In this framework, twist-3 quark-gluon or three-gluon correlation functions in the initial nucleon and the twist-3 fragmentation function for the final hadron play a critical role as a source of the asymmetries. I will summerize the formalism and the characteristics features of the analyses. Though this mechanism is designed for the description of the spin asymmetries in the region of the large transverse momentum P_T of the final hadron, it also provides the asymmetries at lower P_T which is consistent with the transverse-momentum-dependent (TMD) factorization. Some of the functions in the CT3 and TMD factorizations are related to each other by the QCD equation of motion, which allows us to perform a global analysis of the spin asymmetries including both low P_T and large P_T data. I will summerized these features of the CT3 factorization.

Primary author

Prof. Yuji Koike (Niigata University)

Presentation Materials