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Transversity and Collins functions from SIDIS and e+e- data

M. Anselmino·M. Boglione·U. D'Alesio·A. Kotzinian·F. Murgia·A. Prokudin·C. Turk
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Abstract

A global analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e+e- --> h1 h2 X processes, from the BELLE Collaboration, is performed. It results in the extraction of the Collins fragmentation function and, for the first time, of the transversity distribution function for u and d quarks. These turn out to have opposite signs and to be sizably smaller than their positivity bounds. Predictions for the azimuthal asymmetry A_{UT}^{sin(phi_h + phi_S)}, as will soon be measured at JLab and COMPASS operating on a transversely polarized proton target, are then presented.

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M. Anselmino, M. Boglione, U. D'Alesio, A. Kotzinian, F. Murgia, A. Prokudin, C. Turk. 2007-03-28. Transversity and Collins functions from SIDIS and e+e- data. https://doi.org/10.1103/physrevd.75.054032

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