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:
-
- 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}
}