Measurements of the ratio of Drell-Yan yields from an 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 to up antiquark distributions in the proton sea is determined over a wide range in Bjorken- These results confirm previous measurements by E866 and extend them to lower x. From these data, and are evaluated for 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