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Title: Measurement of the light antiquark flavor asymmetry in the nucleon sea

Abstract

A precise measurement made by Fermilab experiment E866 of the ratio of Drell-Yan yields from an 800 GeV/c proton beam incident on hydrogen and deuterium targets is reported. From this ratio of yields the asymmetry between anti-down and anti-up quark distributions in the nucleon is determined over a wide range in Bjorken-x. The x dependence of the ratio of $$\bar{d}$$(x) to $$\bar{u}$$(x) quarks shows a substantial excess of $$\bar{d}$$(x) with respect to $$\bar{u}$$(x) for x < 0:25. For x > 0:25 the data show the $$\bar{d}$$(x) to {anti u}(x) ratio to be much closer to unity. Predictions made by current nucleon structure parameterizations are shown to be in reasonable agreement with the measured asymmetry results below an x of 0.15, but are in sharp disagreement with the results at values of x higher than 0.2. These very same results and issues are discussed in brief in a recent paper [The E866 Collaboration, E. A. Hawker et al., Phys. Rev. Lett. 80, 3715 (1998)]. The asymmetry measurements are also shown to be able to support or reject several current theoretical models which aim to describe the nucleon sea as arising from nonperturbative QCD processes.

Authors:
 [1]
  1. Texas A & M Univ., College Station, TX (United States)
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
3120
Report Number(s):
FERMILAB-THESIS-1998-13
ON: DE00003120; TRN: US0204496
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: TH: Thesis; Thesis information not supplied; PBD: 26 Jan 1999
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; DEUTERIUM TARGET; FERMILAB; HYDROGEN; NUCLEONS; PROTON BEAMS; QUANTUM CHROMODYNAMICS; QUARKS

Citation Formats

Hawker, Eric Andrew. Measurement of the light antiquark flavor asymmetry in the nucleon sea. United States: N. p., 1998. Web. doi:10.2172/3120.
Hawker, Eric Andrew. Measurement of the light antiquark flavor asymmetry in the nucleon sea. United States. https://doi.org/10.2172/3120
Hawker, Eric Andrew. 1998. "Measurement of the light antiquark flavor asymmetry in the nucleon sea". United States. https://doi.org/10.2172/3120. https://www.osti.gov/servlets/purl/3120.
@article{osti_3120,
title = {Measurement of the light antiquark flavor asymmetry in the nucleon sea},
author = {Hawker, Eric Andrew},
abstractNote = {A precise measurement made by Fermilab experiment E866 of the ratio of Drell-Yan yields from an 800 GeV/c proton beam incident on hydrogen and deuterium targets is reported. From this ratio of yields the asymmetry between anti-down and anti-up quark distributions in the nucleon is determined over a wide range in Bjorken-x. The x dependence of the ratio of $\bar{d}$(x) to $\bar{u}$(x) quarks shows a substantial excess of $\bar{d}$(x) with respect to $\bar{u}$(x) for x < 0:25. For x > 0:25 the data show the $\bar{d}$(x) to {anti u}(x) ratio to be much closer to unity. Predictions made by current nucleon structure parameterizations are shown to be in reasonable agreement with the measured asymmetry results below an x of 0.15, but are in sharp disagreement with the results at values of x higher than 0.2. These very same results and issues are discussed in brief in a recent paper [The E866 Collaboration, E. A. Hawker et al., Phys. Rev. Lett. 80, 3715 (1998)]. The asymmetry measurements are also shown to be able to support or reject several current theoretical models which aim to describe the nucleon sea as arising from nonperturbative QCD processes.},
doi = {10.2172/3120},
url = {https://www.osti.gov/biblio/3120}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Aug 01 00:00:00 EDT 1998},
month = {Sat Aug 01 00:00:00 EDT 1998}
}

Thesis/Dissertation:
Other availability
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