Document Type
Article
Department/Program
Physics
Journal Title
Physics Letters B
Pub Date
2015
Volume
744
First Page
309
Abstract
We have performed precision measurements of the double-spin virtual-photon asymmetry A(1) on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized He-3 target. Our data cover a wide kinematic range 0.277 < = x < = 0.548 at an average Q(2) value of 3.078(GeV/c)(2), doubling the available high-precision neutron data in this xrange. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of an A(1)(n) zero crossing near x = 0.5. We find no evidence of a transition to a positive slope in (Delta d + Delta(d) over bar)/(d + (d) over bar) up to x = 0.548. (C) 2015 The Authors. Published by Elsevier B.V.
Recommended Citation
Parno, D. S.; Benmokhtar, F.; Franklin, G. B.; Averett, Todd; Katich, J.; Kelleher, A.; Yao, H.; and Zhao, B., Precision measurements of A(1)(n) in the deep inelastic regime (2015). Physics Letters B, 744, 309-314.
10.1016/j.physletb.2015.03.067
DOI
10.1016/j.physletb.2015.03.067
