The CUPID 0νββ experiment

Parallel talk presented at the XXI International Workshop on Neutrino Telescopes - Padova 29 September - 3 October 2025 (https://agenda.infn.it/event/44606/) On behalf of the CUPID Collaboration Abstract: Neutrinoless double-beta decay (0νββ) is a key process in addressing some of the most significant open questions in particle physics, namely the conservation of lepton number and the Majorana nature of the neutrino. Over the past decades, extensive efforts have been dedicated to improving the sensitivity of 0νββ half-life measurements across multiple isotopes. The next generation of experiments aims to probe half-lives greater than 10²⁷ years, reaching the sensitivity required to explore the Inverted-Ordering region of the neutrino mass spectrum. Among the various techniques employed, low-temperature calorimetry has proven exceptionally promising and is expected to maintain a leading role in future searches, particularly through the CUPID experiment. CUPID (CUORE Upgrade with Particle IDentification) will search for the 0νββ decay of ¹⁰⁰Mo, leveraging the existing cryogenic infrastructure and expertise gained from CUORE, the first tonne-scale low-temperature calorimeter array, currently operating at the Laboratori Nazionali del Gran Sasso in Italy. CUPID will utilize scintillating Li₂MoO₄ crystals enriched in ¹⁰⁰Mo, coupled with light detectors featuring Neganov-Trofimov-Luke amplification. With a total isotope mass of 240 kg, CUPID is designed to achieve a background index of 10⁻⁴ counts/keV/kg/year and a FWHM energy resolution of 5 keV. This performance will allow for a 3σ discovery sensitivity of 1.0 × 10²⁷ years after 10 live-years of data-taking, corresponding to an effective Majorana neutrino mass sensitivity in the range of 12–21 meV. In this talk, we will present the current status of the CUPID experiment and outline the upcoming steps toward its construction. Funds: This work was supported by the IstitutoNazionale di FisicaNucleare(INFN); by the European Research Council (ERC) under the European Union Horizon 2020 program (H2020/2014-2020) with the ERC Advanced Grant no. 742345 (ERC-2016-ADG, project CROSS) and the Marie Sklodowska-Curie Grant Agreement No. 754496; by the Italian Ministry of University and Research (MIUR) through the grant Progettidi ricercadi RilevanteInteresse Nazionale (PRIN) grant no. 2017FJZMCJ and grant no. 2020H5L338; by the US National Science Foundation under Grant Nos. NSF-PHY-1401832, NSF-PHY-1614611, NSF-PHY-2412377 and NSF-PHY-1913374; by the French AgenceNationale de la Recherche (ANR) through the ANR-21-CE31-0014-CUPID-1; by the National Research Foundation of Ukraine (Grant No. 2023.03/0213). This material is also based upon work supported by the US Department of Energy (DOE) Office of Science under Contract Nos. DE-AC02-05CH11231 and DE-AC02-06CH11357; and by the DOE Office of Science, Office of Nuclear Physics under Contract Nos. DE-FG02-08ER41551, DE-SC0011091, DE-SC0012654, DE-SC0019316, DE-SC0019368, and DE-SC0020423. This work was also supported by the Russian Science Foundation under grant No. 18-12-00003.