ANA_N in inclusive lepton-proton collisions: TMD and twist-3 approaches

We consider the inclusive production of hadrons in lepton-nucleon scattering. For a transversely polarized nucleon this reaction shows a left-right azimuthal asymmetry, which we compute this asymmetry in both TMD and in twist-3 collinear factorization formalisms. All non-perturbative parton correlators of the calculation are fixed through information from other hard processes. Our results for the left-right asymmetry agree in sign with recent data for charged pion production from the HERMES Collaboration and from Jefferson Lab. We discuss similarities and differences of two formalisms.Comment: 6 pages, 4 figures, to appear in the proceedings of the TRANSVERSITY 2014, Chia, Italy, 9-13 June, 201

Collins Effect from Polarized SIDIS and e+e−e^+e^- Data

The recent data on the transverse single spin asymmetry $A_{UT}^{\sin(\phi_h+\phi_S)}$ from HERMES and COMPASS Collaborations are analysed within LO parton model with unintegrated parton distribution and fragmentation functions. A fit of SIDIS data from HERMES Collaboration is performed leading to the extraction of favoured and unfavoured Collins fragmentation functions. A very good description of COMPASS data is obtained. BELLE $e^+e^-$ data are shown to be compatible with our estimates based on the extracted Collins fragmentation functions. Predictions for $A_{UT}^{\sin(\phi_h+\phi_S)}$ asymmetries at JLab and COMPASS operating on a proton target are given.Comment: Talk presented at SPIN2006, 4 pages, 6 figure