{"paper":{"title":"Radon-induced backgrounds in the NEXT-100 experiment","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"The radon-induced background index in NEXT-100 drops to ~4×10^{-5} counts/(keV·kg·yr) after a topological cut selecting single double-electron tracks in the 0νββ region of interest.","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A. Brodoline, A. Castillo, A.F.B. Isabel, A. Larumbe, A.L.M. Silva, A. Marauri, A. Mart\\'inez, A. Para, A. Pazos, A.P. Marques, A. Sim\\'on, A. Trettin, A. Yubero-Navarro, B.J.P. Jones, B. Palmeiro, B. Romeo, C.A.N. Conde, C.A.O. Henriques, C.D.R. Azevedo, C. Echeverria, C. Herv\\'es Carrete, C.M.B. Monteiro, C. Rogero, C. Romo-Luque, C. Tonnel\\'e, D.R. Nygren, E. Church, E. Dey, E. Oblak, E. Ruiz-Ch\\'oliz, F. Auria-Luna, F. Ballester, F.I.G.M. Borges, F.J. Mora, F. Kellerer, F. Lopez, F. Monrabal, F.P. Coss\\'io, F.P. Santos, F.W. Foss, G. Mart\\'inez-Lema, H. Almaz\\'an, I.J. Arnquist, I. Osborne, I. Parmaksiz, I. Rivilla, I. Shomroni, J.A. Hernando Morata, J.D. Villamil, J.E. Barcelon, J.F.C.A. Veloso, J.F. Toledo, J. Garc\\'ia-Barrena, J. Hauptman, J.J. G\\'omez-Cadenas, J. Mart\\'in-Albo, J.M. Benlloch-Rodr\\'iguez, J.M.F. dos Santos, J. Molina-Canteras, J.M.R. Teixeira, J. Palacio, J. Pelegrin, J. Renner, J. Soto-Oton, J. Torrent, J. Waiton, J.W.R. Grocott, K.E. Navarro, K. Mistry, L. Arazi, L. Larizgoitia, L.M.P. Fernandes, L.M. Villar Padruno, L. Rogers, M. Cid, M. del Barrio-Torregrosa, M. Elorza, M. Mart\\'inez-Vara, M. P\\'erez Maneiro, M. Querol, M. Seemann, M. Sorel, M. Vanga, N. Byrnes, NEXT Collaboration: C. Cortes-Parra, N. L\\'opez-March, P.A.O.C. Silva, P. Dietz, P. Ferrario, P. Ferrero Manche\\~no, P. Herrero-G\\'omez, P. Lebrun, P. Novella, P.R.G. Valle, P. Saharia, P. V\\'azquez Cabaleiro, R. Coupe, R.D.P. Mano, R. Esteve, R. Felkai, R. Guenette, R.L. Miller, R. Madigan, S. Ayet, S.R. Soleti, S. Teruel-Pardo, S. Torelli, V. \\'Alvarez, V. Herrero, X. Cid, Y. Ayyad, Y. Ifergan, Z. Freixa","submitted_at":"2026-04-21T16:04:32Z","abstract_excerpt":"The NEXT-100 detector at the LSC aims at the first competitive search for the \\bbnonu decay using a high-pressure \\Xe{136} electroluminescent time projection chamber. The first low-background run of NEXT-100 at 3.95 bar has been devoted to the measurement of the radon-induced backgrounds impacting this search. The contributions from both the internal and external airborne radon have been evaluated. The internal \\Rn{222} activity is found to be (0.95$\\pm$0.04(stat)$\\pm$0.09(sys)) Bq/m$^3$, while no traces of \\Rn{220} have been observed. Most of the \\Rn{222} progeny plate-out on the surface of t"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"The radon-induced background index in the neutrinoless double beta decay region of interest is reduced to ~4×10^{-5} counts/(keV·kg·yr) by applying a topological selection requiring only one double-electron-like track, which is one order of magnitude below the total radiogenic background expectation in NEXT-100.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the observed events above 400 keV are correctly attributed to Bi-214 from Rn-222 progeny plate-out on the cathode, and that the efficiencies for fully contained events and the topological selection are accurately modeled without significant bias or unaccounted systematics.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"NEXT-100 measures internal Rn-222 activity at 0.95 Bq/m³ with no Rn-220 detected, yielding a Bi-214 rate of 0.97 Hz above 400 keV and a background index of ~4×10^{-5} counts/(keV·kg·yr) in the 0νββ ROI after topological selection.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"The radon-induced background index in NEXT-100 drops to ~4×10^{-5} counts/(keV·kg·yr) after a topological cut selecting single double-electron tracks in the 0νββ region of interest.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"c100448952ae6bd89d80780f9d08dc8cbc1eea2eb658f62d173e5519ffd7a43b"},"source":{"id":"2604.19616","kind":"arxiv","version":3},"verdict":{"id":"cada5f2f-2628-4c99-925f-ef8c9c99f97b","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-10T00:51:10.117689Z","strongest_claim":"The radon-induced background index in the neutrinoless double beta decay region of interest is reduced to ~4×10^{-5} counts/(keV·kg·yr) by applying a topological selection requiring only one double-electron-like track, which is one order of magnitude below the total radiogenic background expectation in NEXT-100.","one_line_summary":"NEXT-100 measures internal Rn-222 activity at 0.95 Bq/m³ with no Rn-220 detected, yielding a Bi-214 rate of 0.97 Hz above 400 keV and a background index of ~4×10^{-5} counts/(keV·kg·yr) in the 0νββ ROI after topological selection.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the observed events above 400 keV are correctly attributed to Bi-214 from Rn-222 progeny plate-out on the cathode, and that the efficiencies for fully contained events and the topological selection are accurately modeled without significant bias or unaccounted systematics.","pith_extraction_headline":"The radon-induced background index in NEXT-100 drops to ~4×10^{-5} counts/(keV·kg·yr) after a topological cut selecting single double-electron tracks in the 0νββ region of interest."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.19616/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"doi_compliance","ran_at":"2026-05-20T02:41:57.476380Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"5ddcf07f7ea6ae05536ceedb3886d3410164b8497da69983f8613656bb49580b"},"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"}