{"paper":{"title":"Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"CDF Collaboration","submitted_at":"2007-04-04T18:55:03Z","abstract_excerpt":"We have measured the polarizations of $\\jpsi$ and $\\psiprime$ mesons as functions of their transverse momentum $\\pt$ when they are produced promptly in the rapidity range $|y|<0.6$ with $\\pt \\geq 5 \\pgev$. The analysis is performed using a data sample with an integrated luminosity of about $800 \\ipb$ collected by the CDF II detector. For both vector mesons, we find that the polarizations become increasingly longitudinal as $\\pt$ increases from 5 to $30 \\pgev$. These results are compared to the predictions of nonrelativistic quantum chromodynamics and other contemporary models. The effective po"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0704.0638","kind":"arxiv","version":2},"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"}