Neutrino effects in two-body electron-capture measurements at GSI

Oscillatory behavior of electron capture rates in the two-body decay D → R+ ν of hydrogen-like ion (D) into recoil ion (R) plus undetected neutrino ν was reported in storage ring single-ion experiments at the GSI laboratory, Darmstadt, for two cases with period ≈ 7 s. Ivanov and Kienle [Phys. Rev. Lett. 103 (2009) 062502] have relegated this period to neutrino masses through neutrino mixing in the final state. New arguments are given here against this interpretation, while suggesting that these ‘GSI Oscillations’ may be related to interference between chirally entangled final states split by the interaction of the neutrino magnetic moment μν with the magnetic field of the storage ring. This explanation requires that μν is one order of magnitude smaller than the laboratory upper limit μν < 0.54 × 10μB , and its consequences are briefly explored.