Most stringent bound on electron neutrino mass obtained with a scalable low temperature microcalorimeter array

Published

September 29, 2025

Author(s)

Bradley Alpert, Daniel Becker, Douglas Bennett, Joseph Fowler, Johnathon Gard, John Mates, Carl Reintsema, Daniel Schmidt, Daniel Swetz, Joel Ullom, Leila Vale, M. Balata, S. Nisii, A. Bevilacqua, M. De Gerone, G. Gallucci, L. Parodi, F. Siccardi, A. Borghesi, P. Campana, R. Carobene, M. Faverzani, A. Giachero, M. Gobbo, D. Labrbca, R. Morette, A. Nuciotti, L. Origo, S. Ragazzi, G. Ceruti, E. Ferri, G. Pessina, E. Celasco, F. Gatti, R. Dressler, E. Maugeri, D. Schumann, U Koster, M. Lusignoli, P. Manfrinetti, F Ahrens, E Bogini, M. Borghesi, P. Campana, R. Carbene, L. Ferrari Barusso, E. Ferri, G. Gallucci

Abstract

The determination of the absolute neutrino mass scale remains a fundamental open question in particle physics, with profound implications for both the standard model and cosmology. Direct kinematic measurements, independent of model-dependent assumptions, provide the most robust approach to address this challenge. Here we present the most stringent upper bound on the effective electron neutrino mass ever obtained with a calorimetric measurement of the electron capture decay of 163 Ho . The HOLMES experiment employs an array of ion-implanted transition-edge sensor (TES) microcalorimeters, achieving an average energy resolution of 6 eV FWHM with a scalable, multiplexed readout technique. With a total of 7 ×107 decay events recorded over two months and a Bayesian statistical analysis, we derive an upper limit of <27 eV/2 at 90% credibility. These results validate the feasibility of 163 Ho calorimetry for next-generation neutrino mass experiments and demonstrate the potential of a scalable TES-based microcalorimetric technique to push the sensitivity of direct neutrino mass measurements beyond the current state of the art.

Citation

Physical Review Letters

Volume

135

Pub Type

Journals

Download Paper

https://doi.org/10.1103/s9vl-7n24

Local Download

Keywords

micro-calorimeter, neutrino, mass

Citation

Alpert, B. , Becker, D. , Bennett, D. , Fowler, J. , Gard, J. , Mates, J. , Reintsema, C. , Schmidt, D. , Swetz, D. , Ullom, J. , Vale, L. , Balata, M. , Nisii, S. , Bevilacqua, A. , De Gerone, M. , Gallucci, G. , Parodi, L. , Siccardi, F. , Borghesi, A. , Campana, P. , Carobene, R. , Faverzani, M. , Giachero, A. , Gobbo, M. , Labrbca, D. , Morette, R. , Nuciotti, A. , Origo, L. , Ragazzi, S. , Ceruti, G. , Ferri, E. , Pessina, G. , Celasco, E. , Gatti, F. , Dressler, R. , Maugeri, E. , Schumann, D. , Koster, U. , Lusignoli, M. , Manfrinetti, P. , Ahrens, F. , Bogini, E. , Borghesi, M. , Campana, P. , Carbene, R. , Ferrari Barusso, L. , Ferri, E. and Gallucci, G. (2025), Most stringent bound on electron neutrino mass obtained with a scalable low temperature microcalorimeter array, Physical Review Letters, [online], https://doi.org/10.1103/s9vl-7n24, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959676 (Accessed September 30, 2025)