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arXiv · 1910.02931

On the shape of the $\bar d-\bar u$ asymmetry

A. Accardi·C. E. Keppel·S. Li·W. Melnitchouk·J. F. Owens
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Abstract

Using data from a recent reanalysis of neutron structure functions extracted from inclusive proton and deuteron deep-inelastic scattering (DIS), we re-examine the constraints on the shape of the $\bar d-\bar u$ asymmetry in the proton at large parton momentum fractions $x$. A global analysis of the proton-neutron structure function difference from BCDMS, NMC, SLAC and Jefferson Lab DIS measurements, and of Fermilab Drell-Yan lepton-pair production cross sections, suggests that existing data can be well described with $\bar d > \bar u$ for all values of $x$ currently accessible. We compare the shape of the fitted $\bar d-\bar u$ distributions with expectations from nonperturbative models based on chiral symmetry breaking, which can be tested by upcoming Drell-Yan data from the SeaQuest experiment at larger values of $x$.

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A. Accardi, C. E. Keppel, S. Li, W. Melnitchouk, J. F. Owens. 2019-10-07. On the shape of the $\bar d-\bar u$ asymmetry. https://arxiv.org/abs/1910.02931

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