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arXiv · hep-ph/9811333

Search for Exotic Muon Decays

R. Bilger·K. Foehl·H. Clement·M. Croeni·A. Erhardt·R. Meier·J. Paetzold·G. J. Wagner
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Abstract

Recently, it has been proposed that the observed anomaly in the time distribution of neutrino induced reactions, reported by the KARMEN collaboration, can be interpreted as a signal from an exotic muon decay branch mu+ to e+ X. It has been shown that this hypothesis gives an acceptable fit to the KARMEN data if the boson X has a mass of m_X=103.9MeV/c^2, close to the kinematical limit. We have performed a search for the X particle by studying for the first time the very low energy part of the Michel spectrum in mu+ decays. Using a HPGe detector setup at the muE4 beamline at PSI we find branching ratios BR(mu+ to e+ X)<5.7e-4 (90% C.L.) for most of the region 103MeV/c^2<m_X<105MeV/c^2.

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R. Bilger, K. Foehl, H. Clement, M. Croeni, A. Erhardt, R. Meier, J. Paetzold, G. J. Wagner. 1998-11-15. Search for Exotic Muon Decays. https://doi.org/10.1016/s0370-2693(98)01507-x

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