Time Modulation of Orbital Electron Capture Decays of H-like Heavy Ions

TL;DR

This paper discusses the time modulation observed in electron capture decay rates of certain heavy ions, attributing it to neutrino interference effects, and responds to critiques of their previous findings.

Contribution

It provides a detailed reply to comments on their earlier work, reinforcing the neutrino interference explanation for decay rate modulation in heavy ions.

Findings

Decay rates of H-like heavy ions are modulated with periods proportional to their mass number.

Positron decay modes show no time modulation, supporting the neutrino interference hypothesis.

The observed modulation can be explained by the interference of two neutrino mass eigenstates.

Abstract

According to experimental data at GSI, the rates of the number of daughter ions, produced by the nuclear K-shell electron capture (EC) decays of the H-like 140Pr58+, 142Pm60+ and 122I52+ ions, are modulated in time with periods T_{EC} of the order of a few seconds, obeying an A-scaling T_{EC} = A/20 s, where A is the mass number of the mother nuclei, and with amplitudes a^{EC}_d ~ 0.21. In turn, the positron decay mode of the H-like 142Pm60+ ions showed no time modulation of the decay rates. As has been shown in Phys. Rev. Lett. 103, 062502 (2009) and Phys. Rev. Lett. 101, 182501 (2008), these data can be explained by the interference of two massive neutrino mass-eigenstates. In this letter we give a reply on the comments on our paper Phys. Rev. Lett. 103, 062502 (2009) by A. Gal (arXiv:0809.1213v2).