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arXiv · 1404.1033

Towards an explanation of transverse single-spin asymmetries in proton-proton collisions: the role of fragmentation in collinear factorization

K. Kanazawa·Y. Koike·A. Metz·D. Pitonyak
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Abstract

We study the transverse single-spin asymmetry for single-hadron production in proton-proton collisions within the framework of collinear twist-3 factorization in Quantum Chromodynamics. By taking into account the contribution due to parton fragmentation we obtain a very good description of all high transverse-momentum data for neutral and charged pion production from the Relativistic Heavy Ion Collider. Our study may provide the crucial step towards a final solution to the longstanding problem of what causes transverse single-spin asymmetries in hadronic collisions within Quantum Chromodynamics. We show for the first time that it is possible to simultaneously describe spin/azimuthal asymmetries in proton-proton collisions, semi-inclusive deep-inelastic scattering, and electron-positron annihilation by using collinear twist-3 factorization in the first process along with transverse momentum dependent functions extracted from the latter two reactions.

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K. Kanazawa, Y. Koike, A. Metz, D. Pitonyak. 2014-05-30. Towards an explanation of transverse single-spin asymmetries in proton-proton collisions: the role of fragmentation in collinear factorization. https://doi.org/10.1103/physrevd.89.111501

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