Coello Pérez, E.A.Menéndez Sánchez, JavierSchwenk, A.2024-09-172024-09-172019-08-230370-2693https://hdl.handle.net/2445/215201We study the two-neutrino double electron capture on 124Xe based on an effective theory (ET) and large-scale shell model calculations, two modern nuclear structure approaches that have been tested against Gamow-Teller and double-beta decay data. In the ET, the low-energy constants are fit to electron capture and transitions around xenon. For the nuclear shell model, we use an interaction in a large configuration space that reproduces the spectroscopy of nuclei in this mass region. For the dominant transition to the 124Te ground state, we find half-lives y for the ET and y for the shell model. The ET uncertainty leads to a half-life almost entirely consistent with present experimental limits and largely within the reach of ongoing experiments. The shell model half-life range overlaps with the ET, but extends less beyond current limits. Our findings thus suggest that the two-neutrino double electron capture on 124Xe has a good chance to be discovered by ongoing or future experiments. In addition, we present results for the two-neutrino double electron capture to excited states of 124Te.1 p.application/pdfengcc-by (c) E.A. Coello Pérez et al., 2019http://creativecommons.org/licenses/by/4.0/Física de partículesNeutrinsEstructura nuclearParticle physicsNeutrinosNuclear structureinfo:eu-repo/semantics/article6976292024-09-17info:eu-repo/semantics/openAccess