Search for oscillation of the electron-capture decay probability of 142Pm

doi:10.1016/j.physletb.2008.11.004

Physics Letters B

Volume 670, Issue 3, 18 December 2008, Pages 196-199

https://doi.org/10.1016/j.physletb.2008.11.004 Get rights and content

Abstract

We have searched for time modulation of the electron capture decay probability of ¹⁴²Pm in an attempt to confirm a recent claim from a group at the Gesellschaft für Schwerionenforschung (GSI). We produced ¹⁴²Pm via the ¹²⁴Sn(²³Na, 5n)¹⁴²Pm 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 ¹⁴²Nd $K_{α}$ 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 et al. [Y.A. Litvinov, et al., Phys. Lett. B 664 (2008) 162]. A literature search for previous experiments that might have been sensitive to the reported modulation uncovered another example in ¹⁴²Eu electron-capture decay. A reanalysis of the published data shows no oscillatory behavior.

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Acknowledgements

We appreciate the assistance of the technical staff and operators at the 88-Inch Cyclotron. This work was supported by the Director, Office of Science, Office of Nuclear Physics, U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Part of this work was performed under the auspices of the U.S. Department of Energy Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

References (21)

Y.A. Litvinov
Phys. Lett. B
(2008)
C. Giunti
Phys. Lett. B
(2008)
G. Duchêne
Nucl. Instrum. Methods A
(1999)
J.K. Tuli
Nuclear Data Sheets
(2000)
J. Law et al.
Nucl. Phys. A
(1972)
J. Law et al.
Nucl. Phys. A
(1972)
M. Faber
A.N. Ivanov et al.
C. Giunti
H. Geissel
Phys. Rev. Lett.
(1992)

There are more references available in the full text version of this article.

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Search for oscillation of the electron-capture decay probability of 142Pm

Abstract

Section snippets

Acknowledgements

Phys. Lett. B

Phys. Lett. B

Nucl. Instrum. Methods A

Nuclear Data Sheets

Nucl. Phys. A

Nucl. Phys. A

Phys. Rev. Lett.

Search for oscillation of the electron-capture decay probability of ¹⁴²Pm