Search for Oscillation of the Electron-Capture Decay Probability of ${}^{142}$Pm

Abstract

We have searched for time modulation of the electron capture decay probability of ${}^{142}$Pm in an attempt to confirm a recent claim from a group at the Gesellschaft für Schwerionenforschung (GSI). We produced ${}^{142}$Pm via the ${}^{124}$Sn(${}^{23}$Na, 5n)${}^{142}$Pm reaction at the Berkeley 88-Inch Cyclotron with a bombardment time short compared to the reported modulation period. Isotope selection by the Berkeley Gas-filled Separator is followed by implantation and a long period of monitoring the ${}^{142}$Nd K${}_{\alpha }$ x-rays from the daughter. The decay time spectrum of the x-rays is well-described by a simple exponential and the measured half-life of 40.68(53) seconds is consistent with the accepted value. We observed no oscillatory modulation at the proposed frequency at a level 31 times smaller than that reported by Litvinov {\it et al.} (Phys. Lett. B 664 (2008) 162; arXiv:0801.2079 [nucl-ex]). A literature search for previous experiments that might have been sensitive to the reported modulation uncovered another example in ${}^{142}$Eu electron-capture decay. A reanalysis of the published data shows no oscillatory behavior.

12 pages (double-spaced), 6 figures

References in corpus (3)

• Observation of Non-Exponential Orbital Electron Capture Decays of Hydrogen-Like ${}^{140}$Pr and ${}^{142}$Pm Ions
• Measurement of the ${\beta }^{+}$ and orbital electron-capture decay rates in fully-ionized, hydrogen-like, and helium-like ${}^{140}$Pr ions
• Rates of Processes with Coherent Production of Different Particles and the GSI Time Anomaly

Cited by in corpus (1)

• Comment on the paper "Search for oscillation of the electron-capture decay probability of ${}^{142}$Pm" at arXiv:0807.0649v1