Is decay constant?

Research output: Contribution to journalSpecial issuepeer-review


  • Stefaan Pommé
  • Heiko Stroh
  • Timotheos Altzitzoglou
  • Jan Paepen
  • Raf Van Ammel
  • Karsten Kossert
  • O Nähle
  • John D. Keightley
  • Kelley M. Ferreira
  • Leen Verheyen
  • Michel Bruggeman
  • EC - European Commission
  • EC - JRC - European Commission - Joint Research Centre
  • Danish Emergency Management Agency
  • PTB - Physikalisch-Technische Bundesanstalt
  • NPL - National Physical Laboratory

Documents & links


Some authors have raised doubt about the invariability of decay constants, which would invalidate the exponential-decay law and the foundation on which the common measurement system for radioactivity is based. Claims were made about a new interaction – the fifth force – by which neutrinos could affect decay constants, thus predicting changes in decay rates in correlation with the variations of the solar neutrino flux. Their argument is based on the observation of permille-sized annual modulations in particular decay rate measurements, as well as transient oscillations at frequencies near 11 year−1 and 12.7 year−1 which they speculatively associate with dynamics of the solar interior. In this work, 12 data sets of precise long-term decay rate measurements have been investigated for the presence of systematic modulations at frequencies between 0.08 and 20 year−1. Besides small annual effects, no common oscillations could be observed among α, β-, β+ or EC decaying nuclides. The amplitudes of fitted oscillations to residuals from exponential decay do not exceed 3 times their standard uncertainty, which varies from 0.00023 % to 0.023 %. This contradicts the assertion that 'neutrino-induced' beta decay provides information about the deep solar interior.


Original languageEnglish
Pages (from-to)6-12
Number of pages7
JournalApplied Radiation and Isotopes
Early online date3 Sep 2017
Publication statusPublished - Apr 2018


  • Half-life, Decay constant, Radioactivity, Solar cycle, Neutrino, Cognitive bias

ID: 4985697