Improved measurement of the d̄/ū asymmetry in the nucleon sea

R. S. Towell, P. L. McGaughey, T. C. Awes, M. E. Beddo, M. L. Brooks, C. N. Brown, J. D. Bush, T. A. Carey, T. H. Chang, W. E. Cooper, C. A. Gagliardi, G. T. Garvey, D. F. Geesaman, E. A. Hawker, X. C. He, L. D. Isenhower, D. M. Kaplan, S. B. Kaufman, P. N. Kirk, D. D. KoetkeG. Kyle, D. M. Lee, W. M. Lee, M. J. Leitch, Naomi C R Makins, J. M. Moss, B. A. Mueller, P. M. Nord, V. Papavassiliou, B. K. Park, Jen-Chieh Peng, G. Petitt, P. E. Reimer, M. E. Sadler, W. E. Sondheim, P. W. Stankus, T. N. Thompson, R. E. Tribble, M. A. Vasiliev, Y. C. Wang, Z. F. Wang, J. C. Webb, J. L. Willis, D. K. Wise, G. R. Young

Research output: Contribution to journalArticlepeer-review


Measurements of the ratio of Drell-Yan yields from an 800 GeV/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 (d̄) 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, (d̄-ū) and ∫ (d̄-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.

Original languageEnglish (US)
Article number052002
Pages (from-to)52002-1 - 52002-16
Number of pages16
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number5
StatePublished - Sep 1 2001
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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