170144 20260407115446.0 doi 10.1038/s42005-026-02518-6 sideral 148724 ART-2026-148724 eng Cabrera, A. Probing Earth’s missing potassium using the antimatter signature of geoneutrinos 2026 Puzzles exist in our theories of Earth’s formation and bulk chemical composition. Related to these questions is our incomplete knowledge of the planet’s overall heat budget and thermal history. The successful observation of geoneutrinos originating from uranium and thorium decay chains, manifestations of the planet’s natural radioactivity, serves as the only direct probe of Earth’s internal, radiogenic heat engine so far. Intriguingly, potassium (40K) geoneutrinos have never been observed and have so far been considered impractical to measure despite their importance in Earth’s radioactive inventory. We propose here an approach for potassium geoneutrino detection that exploits their antiparticle nature. The detection framework relies on the LiquidO technique to identify positrons, thereby reducing otherwise overwhelming backgrounds. Antineutrino interactions with candidate isotope targets have been thoroughly examined and copper is found to be the ideal isotope able to meet all experimental feasibility conditions. We discuss the challenging experimental requirements to yield a potassium geoneutrino discovery. Access copy available to the general public Unrestricted info:eu-repo/semantics/openAccess by-nc-nd https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Chen, M. Mantovani, F. Serafini, A. Strati, V. Apilluelo, J. Universidad de Zaragoza (orcid)0009-0006-7877-2985 Asquith, L. Beney, J. L. Bezerra, T. J. C. Bongrand, M. Bourgeois, C. Breton, D. Briere, M. Busto, J. Cadiou, A. Calvo, E. Chaumat, V. Chauveau, E. Cattermole, B. J. Chimenti, P. Delafosse, C. de Kerret, H. Dusini, S. Earle, A. Frigerio-Martins, C. Galán, J. García, J. A. Universidad de Zaragoza (orcid)0000-0002-7399-7353 Gazzini, R. Gibson-Foster, A. Gallas, A. Girard-Carillo, C. Griffith, W. C. Haddad, F. Hartnell, J. Hourlier, A. Hull, G. Irastorza, I. G. Koch, L. Laniéce, P. Le Du, J. F. Lefebvre, C. Lefevre, F. Legrand, F. Loaiza, P. Lock, J. A. Luzón, G. Universidad de Zaragoza (orcid)0000-0002-5352-1884 Maalmi, J. Marquet, C. Martínez, M. Mathon, B. Ménard, L. Navas-Nicolás, D. Nunokawa, H. Ochoa-Ricoux, J. P. Obolensky, M. Palomares, C. Pillot, P. Porter, J. C. C. Pravikoff, M. S. Ramarijaona, H. Roche, M. Rosier, P. Roskovec, B. Sarsa, M. L. Universidad de Zaragoza (orcid)0000-0002-7552-1228 Shorrock, W. Simard, L. Steiger, H. Th. J. Stocco, D. Stutzmann, J. S. Suekane, F. Tunc, A. Verdier, M. -A. Verdugo, A. Viaud, B. Wakely, S. M. Yermia, F. 2004 390 Universidad de Zaragoza Dpto. Física Teórica Área Física Atóm.Molec.y Nucl. 9, 1 (2026), [14 pp.] Communications Physics 2399-3650 1998594 http://zaguan.unizar.es/record/170144/files/texto_completo.pdf Versión publicada 2911138 http://zaguan.unizar.es/record/170144/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:170144 articulos driver 2026-03-26-14:30:24 ARTICLE