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arXiv · 0907.2942

What can break the Wandzura--Wilczek relation?

Alberto Accardi·Alessandro Bacchetta·W. Melnitchouk·Marc Schlegel
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Abstract

We analyze the breaking of the Wandzura-Wilczek relation for the g_2 structure function, emphasizing its connection with transverse momentum dependent parton distribution functions. We find that the relation is broken by two distinct twist-3 terms, and clarify how these can be separated in measurements of double-spin asymmetries in semi-inclusive deep inelastic scattering. Through a quantitative analysis of available g_2 data we also show that the breaking of the Wandzura-Wilczek relation can be as large as 15-30% of the size of g_2.

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Alberto Accardi, Alessandro Bacchetta, W. Melnitchouk, Marc Schlegel. 2009-07-17. What can break the Wandzura--Wilczek relation?. https://doi.org/10.1088/1126-6708/2009/11/093

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