Measurement of the flavor asymmetry in the nucleon sea /
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...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=732834181&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | 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-z. The z dependence of the ratio of [#(z)] to ['p,(z)] quarks shows a substantial excess of [#(z)] with respect to [/(z)] for x < 0.25. For x > 0.25 the data show the [#(z)] to ['p,(z)] ratio to be much closer to unity. Predictions made by current nucleon structure parametrizations 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. |
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| Item Description: | Vita. |
| Physical Description: | xii, 94 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references: pages 90-92. |