Generalized Lomb-Scargle analysis of $\rm{^{123}I}$ and $\rm{^{99m}Tc}$ decay rate measurements

TL;DR

This study applies the generalized Lomb-Scargle periodogram to decay rate data of 3I and 9mTc to search for sinusoidal modulations, finding no evidence of periodicities at various frequencies.

Contribution

It provides an independent analysis of radionuclide decay rates using a robust periodogram method, with publicly available data and code.

Findings

No sinusoidal modulation detected at any tested frequencies.

Analysis confirms the stability of decay rates over time.

Data and code are publicly accessible for further research.

Abstract

We apply the generalized Lomb-Scargle periodogram to the $\rm{^{123}I}$ and $\rm{^{99m}Tc}$ decay rate measurements based on data taken at the Bronson Methodist Hospital. The aim of this exercise was to carry out an independent search for sinusoidal modulation for these radionuclei (to complement the analysis in Borrello et al) at frequencies for which other radionuclei have shown periodicities. We do not find evidence for such a modulation at any frequencies, including annual modulation or at frequencies associated with solar rotation. Our analysis codes and datasets have been made publicly available.