{"paper":{"title":"Breakdown of the Isobaric Multiplet Mass Equation for the A = 20 and 21 Multiplets","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"A. A. Kwiatkowski, A. Bader, A. Chaudhuri, A. Grossheim, A. Lennarz, A. Magilligan, A. Schwenk, A. Teigelh\\\"ofer, A. T. Gallant, B. A. Brown, B. E. Schultz, C. Andreoiu, H. Heggen, J. D. Holt, J. Dilling, J. Lassen, J. Men\\'endez, J. Simonis, K. G. Leach, M. Brodeur, R. Klawitter, S. Raeder, T. D. Macdonald, U. Chowdhury","submitted_at":"2014-09-04T16:08:58Z","abstract_excerpt":"Using the Penning trap mass spectrometer TITAN, we performed the first direct mass measurements of 20,21Mg, isotopes that are the most proton-rich members of the A = 20 and A = 21 isospin multiplets. These measurements were possible through the use of a unique ion-guide laser ion source, a development that suppressed isobaric contamination by six orders of magnitude. Compared to the latest atomic mass evaluation, we find that the mass of 21Mg is in good agreement but that the mass of 20Mg deviates by 3{\\sigma}. These measurements reduce the uncertainties in the masses of 20,21Mg by 15 and 22 t"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1409.1477","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"}