{"paper":{"title":"Measurement of the reduced dipole matrix element in Ba$^+$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["quant-ph"],"primary_cat":"physics.atom-ph","authors_text":"K. J. Arnold, M. D. Barrett, M. D. K. Lee, N. Jayjong","submitted_at":"2026-07-23T04:56:43Z","abstract_excerpt":"We present a high-precision measurement of the reduced electric-dipole matrix element $\\langle P_{1/2}\\|r\\|S_{1/2}\\rangle$ in $^{138}\\mathrm{Ba}^+$. By comparing off-resonant scattering rates with dispersive Stark-shift measurements, we determine the matrix element to be $3.322\\,7(12)$, corresponding to a $P_{1/2}$ excited-state radiative lifetime of $7.866\\,3(56)$~ns. Combining our experimental results with a prior model for the differential scalar polarizability $\\Delta\\alpha_0(\\omega)$, we extract the static value $\\Delta\\alpha_0(0) = -73.09(12)$a.u. This determination directly improves the"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.20920","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2607.20920/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}