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arXiv · 0902.0184

Transverse Spin Physics at COMPASS

Federica Sozzi
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Abstract

The study of transverse spin effects is part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS. COMPASS investigates the transversity PDFs in semi-inclusive DIS, using a longitudinally polarized muon beam of 160 GeV/c impinging on a transversely polarized target. From 2002 to 2004, data have been collected using a $^6$LiD target transversely polarized. Transversity has been measured using different quark polarimeters: the azimuthal distribution of single hadrons, the azimuthal dependence of the plane containing hadron pairs, and the measurement of the transverse polarization of baryons ($\Lambda$ hyperons). All the asymmetries have been found to be small, and compatible with zero, a result which has been interpreted as a cancellation between the u and d-quark contributions. In 2007 COMPASS has taken data using a NH$_3$ polarized proton target which will give complementary information on transverse spin effects.

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Federica Sozzi. 2009-02-02. Transverse Spin Physics at COMPASS. https://arxiv.org/abs/0902.0184

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