Regular Article - Experimental Physics
Generalized Lomb–Scargle analysis of decay rate measurements from the Physikalisch–Technische Bundesanstalt
Department of Physics, IIT Hyderabad, Kandi, Sangareddy, Telangana, 502285, India
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Accepted: 2 July 2018
Published online: 6 July 2018
We apply the generalized Lomb–Scargle (LS) periodogram to independently confirm the claim by Sturrock et al. (Astropart Phys 84:8. https://doi.org/10.1016/j.astropartphys.2016.07.005, 2016) of an oscillation at a frequency of 11/year in the decay rates of from measurements at the Physikalisch Technische Bundesanstalt (PTB), which however has been disputed by Kossert and Nahle (Astropart Phys 69:18. https://doi.org/10.1016/j.astropartphys.2015.03.003, 2015). For this analysis, we made two different ansatze for the errors. For each peak in the LS periodogram, we evaluate the statistical significance using non-parametric bootstrap resampling. We find using both of these error models evidence for 11/year periodicity in the data for two of the three samples, but at a lower significance than claimed by Sturrock et al. .
© The Author(s), 2018