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arXiv · 1110.2419

Constraints on the large-x d/u ratio from electron-nucleus scattering at x>1

O. Hen·A. Accardi·W. Melnitchouk·E. Piasetzky
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Abstract

Recently the ratio of neutron to proton structure functions F_2n/F_2p was extracted from a phenomenological correlation between the strength of the nuclear EMC effect and inclusive electron-nucleus cross section ratios at x>1. Within conventional models of nuclear smearing, this "in-medium correction" (IMC) extraction constrains the size of nuclear effects in the deuteron structure functions, from which the neutron structure function F_2n is usually extracted. The IMC data determine the resulting proton d/u quark distribution ratio, extrapolated to x=1, to be 0.23 +- 0.09 with a 90% confidence level. This is well below the SU(6) symmetry limit of 1/2 and significantly above the scalar diquark dominance limit of 0.

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O. Hen, A. Accardi, W. Melnitchouk, E. Piasetzky. 2011-10-11. Constraints on the large-x d/u ratio from electron-nucleus scattering at x>1. https://doi.org/10.1103/physrevd.84.117501

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