Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Research Briefing
  • Published:

Mass difference measurements help to determine the neutrino mass

The Q-value of electron capture in 163Ho has been determined with an uncertainty of 0.6 eV c–2 through a combination of high-precision Penning-trap mass spectrometry and precise atomic physics calculations. This high-precision measurement provides insight into systematic errors in neutrino mass measurements.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Comparison of indirect and direct measurements of the Q-value of 163Ho electron capture.


  1. Fukuda, Y. et al. Evidence for oscillation of atmospheric neutrinos. Phys. Rev. Lett. 81, 1562–1567 (1998). This paper reports the observation of neutrino flavour oscillations.

    Article  ADS  Google Scholar 

  2. The KATRIN collaboration. Direct neutrino-mass measurement with sub-electronvolt sensitivity. Nat. Phys. 18, 160–166 (2022). This paper reports the direct measurement of the neutrino mass with sub-eV sensitivity.

    Article  Google Scholar 

  3. Gastaldo, L. et al. The electron capture in 163Ho experiment - ECHo. Eur. Phys. J. ST 226, 1623–1694 (2017). A review article that provides an overview of the ECHo experiment.

    Article  Google Scholar 

  4. Filianin, P. et al. Direct Q-value Determination of the β decay of 187Re. Phys. Rev. Lett. 127, 072502 (2021). This paper reports the measurement of the Q-value of 187Re and introduces Pentatrap.

    Article  ADS  Google Scholar 

  5. Sturm, S. et al. High-precision measurement of the atomic mass of the electron. Nature 506, 467–470 (2014). This paper reports the measured atomic mass of the electron used in this experiment.

    Article  ADS  Google Scholar 

  6. Eliseev, S. et al. Direct Measurement of the Mass Difference of 163Ho and 163Dy Solves the Q-Value Puzzle for the Neutrino Mass Determination. Phys. Rev. Lett. 115, 062501 (2015). This paper reports the previous best direct measurement of the Q-value of 163Ho electron capture.

    Article  ADS  Google Scholar 

  7. Schweiger, C. et al. Production of highly charged ions of rare species by laser-induced desorption inside an electron beam ion trap. Rev. Sci. Instrum. 90, 123201 (2019). This paper reports the production of highly charged ions of rare species.

    Article  ADS  Google Scholar 

Download references

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

This is a summary of: Schweiger, C. et al. Penning-trap measurement of the Q value of electron capture in 163Ho for the determination of the electron neutrino mass. Nat. Phys. (2024).

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mass difference measurements help to determine the neutrino mass. Nat. Phys. 20, 901–902 (2024).

Download citation

  • Published:

  • Issue Date:

  • DOI:


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing