Search for Exotic Muon Decays

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.

9 pages

References in corpus (3)

• Remarks on the KARMEN Anomaly
• Search for the Hypothetical pi -> mu x Decay
• Exotic muon decays and the KARMEN anomaly

Cited by in corpus (12)

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• The KARMEN Time Anomaly: Search for a Neutral Particle of Mass 33.9 MeV in Pion Decay
• Improved search for two body muon decay ${\mu }^{+}\to e^{+}{X}_H$
• Upper limits on branching ratios of the lepton-flavor-violating decays $\tau \to \ell \gamma \gamma$ and $\tau \to \ell X$
• Experimental searches for muon decays beyond the Standard Model
• Revisiting for maximal flavor violating $Z_{e\mu }^{{}^{\prime }}$ and its phenomenology constraints
• A search for a cosmologically-relevant boson in muon decay
• Does the KARMEN time anomaly originate from a beam-correlated background?
• Search for a Non-Relativistic Boson in Two-Body Antimuon Decay