Improved measurement of the positive-muon lifetime and determination of the fermi constant

D. B. Chitwood, T. I. Banks, M. J. Barnes, S. Battu, R. M. Carey, S. Cheekatmalla, S. M. Clayton, J. Crnkovic, K. M. Crowe, P. T. Debevec, S. Dhamija, W. Earle, A. Gafarov, K. Giovanetti, T. P. Gorringe, F. E. Gray, M. Hance, D. W. Hertzog, M. F. Hare, P. KammelB. Kiburg, J. Kunkle, B. Lauss, I. Logashenko, K. R. Lynch, R. McNabb, J. P. Miller, F. Mulhauser, C. J.G. Onderwater, C. S. Özben, Q. Peng, C. C. Polly, S. Rath, B. L. Roberts, V. Tishchenko, G. D. Wait, J. Wasserman, D. M. Webber, P. Winter, P. A. Zołnierczuk

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The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, τμ=2.197013(24)μs, is in excellent agreement with the previous world average. The new world average τμ=2.197019(21)μs determines the Fermi constant GF=1.166371(6)×10-5GeV-2 (5 ppm). Additionally, the precision measurement of the positive-muon lifetime is needed to determine the nucleon pseudoscalar coupling gP.

Original languageEnglish (US)
Article number032001
JournalPhysical Review Letters
Issue number3
Publication statusPublished - Jul 16 2007
Externally publishedYes


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Chitwood, D. B., Banks, T. I., Barnes, M. J., Battu, S., Carey, R. M., Cheekatmalla, S., ... Zołnierczuk, P. A. (2007). Improved measurement of the positive-muon lifetime and determination of the fermi constant. Physical Review Letters, 99(3), [032001].