{"paper":{"title":"First direct constraints on Fierz interference in free neutron $\\beta$ decay","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"A. Garc\\'ia, A. Knecht, A. P\\'erez Galv\\'an, A. R. Young, A. Saunders, A. T. Holley, B. A. Zeck, B. Plaster, B. VornDick, B. W. Filippone, C. L. Morris, C. Wrede, C.-Y. Liu, D. Bravo-Bergu\\~no, D. Melconian, E. I. Sharapov, E. Tatar, J. C. Ramsey, J. Hoagland, J. L. Liu, Jr., J. W. Martin, K. P. Hickerson, L. J. Broussard, M. A.-P. Brown, M. L. Pitt, M. Makela, M. P. Mendenhall, P. Geltenbort, R. B. Vogelaar, R. Carr, R. Hong, R. Picker, R. Rios, R. R. Mammei, R. W. Pattie, S. Currie, S. D. Moore, S. J. Seestrom, T. M. Ito, W. E. Sondheim, X. Ding, X. Sun, Y. Bagdasarova","submitted_at":"2017-07-03T23:06:42Z","abstract_excerpt":"Precision measurements of free neutron $\\beta$-decay have been used to precisely constrain our understanding of the weak interaction. However the neutron Fierz interference term $b_n$, which is particularly sensitive to Beyond-Standard-Model tensor currents at the TeV scale, has thus far eluded measurement. Here we report the first direct constraints on this term, finding $b_n = 0.067 \\pm 0.005_{\\text{stat}} {}^{+0.090}_{- 0.061}{}_{\\text{sys}}$, consistent with the Standard Model. The uncertainty is dominated by absolute energy reconstruction and the linearity of the beta spectrometer energy "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1707.00776","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"}