Improved measurement of the d¯/ū asymmetry in the nucleon sea

Phys. Rev. D 64, 052002 – Published 10 August 2001
R. S. Towell et al. (FNAL E866/NuSea Collaboration)


Measurements of the ratio of Drell-Yan yields from an 800GeV/c proton beam incident on liquid hydrogen and deuterium targets are reported. Approximately 360 000 Drell-Yan muon pairs remained after all cuts on the data. From these data, the ratio of down antiquark (d¯) to up (ū) antiquark distributions in the proton sea is determined over a wide range in Bjorken-x. These results confirm previous measurements by E866 and extend them to lower x. From these data, (d¯-ū) and (d¯-ū)dx are evaluated for 0.015<x<0.35. These results are compared with parametrizations of various parton distribution functions, models and experimental results from NA51, NMC and HERMES.


  • Received 14 March 2001
  • Published 10 August 2001

© 2001 The American Physical Society

Authors & Affiliations

References (Subscription Required)

Authorization Required




Log In



Article Lookup
Paste a citation or DOI

Enter a citation
  1. Enter a citation to look up or terms to search.

    Ex: "PRL 112 068103", "Phys. Rev. Lett. 112, 068103", "10.1103/PhysRevLett.112.068103"