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Most Stringent Bound on Electron Neutrino Mass Obtained with a Scalable Low-Temperature Microcalorimeter Array

B. K. Alpert1, M. Balata2, D. T. Becker3, D. A. Bennett1, M. Borghesi4,5,*, P. Campana4,5, R. Carobene4,5, M. De Gerone6, W. B. Doriese1 et al.

M. Faverzani4,5, L. Ferrari Barusso7,6, E. Ferri5, J. W. Fowler1, G. Gallucci6, S. Gamba4,5, J. D Gard3, F. Gatti7,6, A. Giachero4,5, M. Gobbo4,5, U. Köster8, D. Labranca4,5, M. Lusignoli9,10, P. Manfrinetti11, J. A. B. Mates1, E. Maugeri12, R. Moretti4,5, S. Nisi2, A. Nucciotti4,5,†, G. C. O’Neil1, L. Origo4,5, G. Pessina5, S. Ragazzi4,5, C. D. Reintsema1, D. R. Schmidt1,‡, D. Schumann12, D. S Swetz1, Z. Talip12, J. N. Ullom1,§, and L. R. Vale1

  • *Contact author: matteo.borghesi@unimib.it
  • †Contact author: angelo.nucciotti@unimib.it
  • ‡Contact author: dan.schmidt@nist.gov
  • §Contact author: joel.ullom@nist.gov
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Phys. Rev. Lett. 135, 141801 – Published 29 September, 2025

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

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 Ho163. 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 mβ<27  eV/c2 at 90% credibility. These results validate the feasibility of Ho163 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.

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References (51)

  1. The Juno Collaboration, Chin. Phys. C 49, 033104 (2025).
  2. The DUNE Collaboration, Eur. Phys. J. C 80, 978 (2020).
  3. S. Abe et al. (KamLAND-Zen Collaboration), Phys. Rev. Lett. 130, 051801 (2023).
  4. D. Q. Adams et al. (CUORE Collaboration), Nature (London) 604, 53 (2022).
  5. M. Agostini et al. (GERDA Collaboration), Phys. Rev. Lett. 125, 252502 (2020).
  6. G. Anton et al. (EXO-200 Collaboration), Phys. Rev. Lett. 123, 161802 (2019).
  7. S. Gariazzo, O. Mena, and T. Schwetz, Phys. Dark Universe 40, 101226 (2023).
  8. D. Wang, O. Mena, E. Di Valentino, and S. Gariazzo, Phys. Rev. D 110, 103536 (2024).
  9. M. Aker et al. (The KATRIN Collaboration), Nat. Phys. 18, 160 (2022).
  10. N. Kovac, F. Adam, S. Kempf, M.-C. Langer, M. Müller, R. Sack, M. Schlösser, M. Steidl, and K. Valerius, Nucl. Instrum. Methods Phys. Res., Sect. A 1080, 170662 (2025).
  11. A. Ashtari Esfahani et al. (Project 8 Collaboration), J. Phys. G: Nucl. Part. Phys. 44, 054004 (2017).
  12. A. A. S. Amad et al., arXiv:2412.06338.
  13. M. Betti et al., J. Cosmol. Astropart. Phys. 07 (2019) 047.
  14. A. Ashtari Esfahani et al. (Project 8 Collaboration), Phys. Rev. Lett. 131, 102502 (2023).
  15. A. Nucciotti, Adv. High Energy Phys. 2016, 1 (2016).
  16. A. Nucciotti, Eur. Phys. J. C 74, 3161 (2014).
  17. A. Nucciotti, E. Ferri, and O. Cremonesi, Astropart. Phys. 34, 80 (2010).
  18. C. Arnaboldi, C. Brofferio, O. Cremonesi, E. Fiorini, C. Lo Bianco, L. Martensson, A. Nucciotti, M. Pavan, G. Pessina, S. Pirro, E. Previtali, M. Sisti, A. Giuliani, B. Margesin, and M. Zen, Phys. Rev. Lett. 91, 161802 (2003).
  19. M. Sisti, C. Arnaboldi, C. Brofferio, G. Ceruti, O. Cremonesi, E. Fiorini, A. Giuliani, B. Margesin, L. Martensson, A. Nucciotti, M. Pavan, G. Pessina, S. Pirro, E. Previtali, L. Soma, and M. Zen, Nucl. Instrum. Methods Phys. Res., Sect. A 520, 125 (2004).
  20. F. Gatti, Nucl. Phys. B, Proc. Suppl. 91, 293 (2001).
  21. B. Alpert et al., Eur. Phys. J. C 75, 112 (2015).
  22. L. Gastaldo et al., Eur. Phys. J. Special Topics 226, 1623 (2017).
  23. M. P. Croce, M. W. Rabin, V. Mocko, G. J. Kunde, E. R. Birnbaum, E. M. Bond, J. W. Engle, A. S. Hoover, F. M. Nortier, A. D. Pollington, W. A. Taylor, N. R. Weisse-Bernstein, L. E. Wolfsberg, J. P. Hays-Wehle, D. R. Schmidt, D. S. Swetz, J. N. Ullom, T. E. Barnhart, and R. J. Nickles, J. Low Temp. Phys. 184, 958 (2016).
  24. A. De Rújula and M. Lusignoli, Phys. Lett. 118B, 429 (1982).
  25. C. Velte et al., Eur. Phys. J. C 79, 1026 (2019).
  26. C. A. Moura and F. Rossi-Torres, Universe 8, 42 (2022).

  27. The total fluorescence yield is expected to be of the order of 10−4.

  28. C. Schweiger et al., Nat. Phys. 20, 921 (2024).
  29. R. G. H. Robertson, Phys. Rev. C 91, 035504 (2015).
  30. A. De Rújula and M. Lusignoli, J. High Energy Phys. 05 (2016) 015.
  31. A. Faessler, L. Gastaldo, and F. Šimkovic, Phys. Rev. C 95, 045502 (2017).
  32. M. Brass and M. W. Haverkort, New J. Phys. 22, 093018 (2020).
  33. B. Alpert et al., Eur. Phys. J. C 79, 304 (2019).
  34. M. Borghesi et al., Nucl. Instrum. Methods Phys. Res., Sect. A 1051, 168205 (2023).
  35. D. Becker et al., J. Instrum. 14, P10035 (2019).
  36. M. Borghesi, Toward the first neutrino mass measurement of Holmes, Ph.D. thesis, University of Milano-Bicocca, Milano, Italy, 2022.
  37. J. Schweppe, R. Deslattes, T. Mooney, and C. Powell, J. Electron Spectrosc. Relat. Phenom. 67, 463 (1994).
  38. J. A. Bearden, Rev. Mod. Phys. 39, 78 (1967).
  39. M. O. Krause and J. H. Oliver, J. Phys. Chem. Ref. Data 8, 329 (1979).
  40. P. C.-O. Ranitzsch, C. Hassel, M. Wegner, D. Hengstler, S. Kempf, A. Fleischmann, C. Enss, L. Gastaldo, A. Herlert, and K. Johnston, Phys. Rev. Lett. 119, 122501 (2017).

  41. We find that the time resolution of our detectors is completely independent of the implanted activity. It is primarily determined by the signal sampling time, approximately a few microseconds, which is therefore better than the signal rise time.

  42. M. Borghesi, Eur. Phys. J. Plus 139, 188 (2024).
  43. See Supplemental Material at http://link.aps.org/supplemental/10.1103/s9vl-7n24 for the binned data of the Ho163 calorimetric spectrum measured by HOLMES in the region of interest, which were used for the Bayesian parameter estimation.
  44. Stan is a probabilistic programming language for statistical modeling, Stan Development Team, Stan Reference Manual, version 2.34.1, https://mc-stan.org (https://mc-stan.org/docs/2_34/cmdstan-guide/index.html) (2024).
  45. S. Heinitz, N. Kivel, D. Schumann, U. Köster, M. Balata, M. Biasotti, V. Ceriale, M. De Gerone, M. Faverzani, E. Ferri, G. Gallucci, F. Gatti, A. Giachero, S. Nisi, A. Nucciotti, A. Orlando, G. Pessina, A. Puiu, and S. Ragazzi, PLoS One 13, e0200910 (2018).
  46. M. De Gerone et al., Nucl. Instrum. Methods Phys. Res., Sect. A 1051, 168168 (2023).
  47. S. McHugh, B. A. Mazin, B. Serfass, S. Meeker, K. O’Brien, R. Duan, R. Raffanti, and D. Werthimer, Rev. Sci. Instrum. 83, 044702 (2012).
  48. D. Q. Adams et al., Prog. Part. Nucl. Phys. 122, 103902 (2022).
  49. A. Agrawal et al. (The AMoRE Collaboration), Eur. Phys. J. C 85, 9 (2025).
  50. M. Mohseni et al., arXiv:2411.10406.
  51. L. Ferrari Barusso et al., IEEE Trans. Appl. Supercond. 35, 1 (2025).

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Phys. Rev. Lett. 135, 141801– Published 29 September, 2025
  • Received 17 March 2025
  • Revised 3 July 2025
  • Accepted 14 August 2025
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