2026-09-21T03:31:59Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/109313 2023-07-11 col_2142_5131 col_2142_8859 com_2142_5130 com_2142_8858 com_2142_234

Peng, Jen-Chieh Makins, Naomi Shelton, Jessie Abbamonte, Peter Dove, Jason 2021-03-05T21:33:11Z 2021-03-05T21:33:11Z 2020-07-23 2020-12 Surprisingly large flavor asymmetry of the light-quark sea in the proton was reported in deep-inelastic scattering and Drell-Yan experiments. The Bjorken-$x$ dependence of the $\bar{d}/\bar{u}$ ratio extracted from the Fermilab E866 experiment also revealed an intriguing drop at the highest values of $x$. The Fermilab E906/SeaQuest experiment was designed to measure $\bar{d}/\bar{u}$ with improved accuracy at high Bjorken-$x$. By detecting high-mass dimuon events produced in the interaction of 120 GeV proton beam with liquid hydrogen (LH$_2$) and deuterium (LD$_2$) targets, the SeaQuest experiment probes the $\bar{d}/\bar{u}$ ratio up to $x\approx 0.45$. Data collection has been completed and the status of data analysis for SeaQuest is presented. Two different methods for extracting the LD$_2$/LH$_2$ Drell-Yan cross section ratios for $0.1\leq x \leq 0.45$ are presented and the results are in reasonable agreement. These ratios allow for the extraction of $\bar{d}/\bar{u}$ revealing an absence of the drop at large $x$ reported earlier by E866. Results from this work are compared with various theoretical models for the flavor structure of the nucleon sea. Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2021-03-04 without embargo terms The student, Jason Dove, accepted the attached license on 2020-07-17 at 15:07. The student, Jason Dove, submitted this Dissertation for approval on 2020-07-17 at 16:42. This Dissertation was approved for publication on 2020-07-23 at 17:27. DSpace SAF Submission Ingestion Package generated from Vireo submission #15684 on 2021-03-04 at 15:32:52 Made available in DSpace on 2021-03-05T21:33:11Z (GMT). No. of bitstreams: 5 DOVE-DISSERTATION-2020.pdf: 2694718 bytes, checksum: 36f5eefea401a3dfbc8fff3375c220ec (MD5) CertificateOfCompletion.pdf: 121781 bytes, checksum: 3fa19a0cf154032622c0bd82650fc4b1 (MD5) Thesis.zip: 4572641 bytes, checksum: 0efe8eed9602e7120fab3a051ca3baa1 (MD5) LICENSE.txt: 4207 bytes, checksum: f88df9c1368473bebeba0f8b719ea626 (MD5) PROQUEST_LICENSE.txt: 4553 bytes, checksum: 92e67a6da638f693f5f680c2b31012d3 (MD5) Previous issue date: 2020-07-23 application/pdf http://hdl.handle.net/2142/109313 en Copyright 2020 Jason Dove nuclear physics proton fixed target parton distribution function Fermilab deep-inelastic scattering E906 SeaQuest Probing the flavor dependence of proton's light-quark sea in the SeaQuest experiment at Fermilab text Thesis Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.