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Title: Muon decay: Measurement of the transverse e+ polarization and its implications on GF and time reversal invariance

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.2220415· OSTI ID:20875863
; ; ; ; ; ; ;  [1]; ; ; ; ; ;  [2];  [3]
  1. Institut fuer Teilchenphysik, ETH Zuerich, CH-8093 Zurich (Switzerland)
  2. Institute of Physics, Jagellonian University, Cracow (Poland)
  3. Institute of Physics, University of Silesia, Katowice (Poland)

The transverse polarization components of the positrons from the decay of polarized muons have been measured at the Paul Scherrer Institute by annihilating in flight the decay positrons with polarized electrons. The use of a stroboscopic method greatly reduces systematic errors. The energy dependence of the transverse polarization component PT1, which lies in the plane defined by muon spin and positron momentum, yields the low energy parameter {eta} = (-2 {+-} 8) x 10 -3 and thus an improved model-independent value of the Fermi coupling constant. For the transverse polarization PT2, averaged over the positron energy, we obtain <PT2> = (-4 {+-} 8) x 10-3. This improves the previous limit on the violation of time invariance in muon decay by a factor of three.

OSTI ID:
20875863
Journal Information:
AIP Conference Proceedings, Vol. 842, Issue 1; Conference: 17. international conference on particles and nuclei, Santa Fe, NM (United States), 23-30 Oct 2005; Other Information: DOI: 10.1063/1.2220415; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English