Rs. Towell et al., Improved measurement of the (d)over-bar/(u)over-bar asymmetry in the nucleon sea - art. no. 052002, PHYS REV D, 6405(5), 2001, pp. 2002
Measurements of the ratio of Drell-Yan yields from an 800 GeV/c proton beam
incident on liquid hydrogen and deuterium targets are reported. Approximat
ely 360 000 Drell-Yan muon pairs remained after all cuts on the data. From
these data, the ratio of down antiquark ((d) over bar) to up ((u) over bar)
antiquark distributions in the proton sea is determined over a wide range
in Bjorken-x. These results confirm previous measurements by E866 and exten
d them to lower x. From these data, ((d) over bar-(u) over bar) and integra
l((d) over bar-(u) over bar )dx are evaluated for 0.015<x<0.35. These resul
ts are compared with parametrizations of various par-ton distribution funct
ions, models and experimental results from NA51, NMC and HERMES.