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Absolute Branching Ratio Normalization for Rare pi+ and mu+ Decays in the PIBETA Experiment

E. Frlez
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Abstract

We have used the PIBETA detector at the PSI for a precise measurement of rare pion and muon weak decays. We have collected a large statistical sample of (1) pi+ -> e+ nu, (2) pi+ -> pi0 e+ nu, (3) pi+ -> e+ nu gamma, (4) mu+ -> e+ nu nu, and (5) mu+ -> e+ nu nu gamma decays. We have evaluated the absolute branching ratios for these processes by normalizing to the independently measured number of decaying pi+'s (or mu+'s). We discuss the mutual consistency of the preliminary results.

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E. Frlez. 2003-12-10. Absolute Branching Ratio Normalization for Rare pi+ and mu+ Decays in the PIBETA Experiment. https://arxiv.org/abs/hep-ex/0312025

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