{"paper":{"title":"Improved Measurement of the $\\bar d / \\bar u$ Asymmetry in the Nucleon Sea","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"et al, FNAL E866/NuSea Collaboration: R. S. Towell, P. L. McGaughey","submitted_at":"2001-03-20T14:11:37Z","abstract_excerpt":"Measurements of the ratio of Drell-Yan yields from an 800 \\rm{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.\n  From these data, the ratio of anti-down ($\\bar{d}$) to anti-up ($\\bar{u}$) quark 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, $(\\bar{d}-\\bar{u})$ and $\\int(\\bar{d}-\\bar{u})dx$ are evaluated for $0.015<x<0.35$. These results are compared wi"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ex/0103030","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}