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Updated: May 24, 2026

Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
Precise measurement of the pi+-->pi0 e+nu branching ratio
D Pocanić1, E Frlez, V A Baranov
1Department of Physics, University of Virginia, Charlottesville, VA 22904-4714, USA. pocanic@virginia.edu
Abstract:
Using a large acceptance calorimeter and a stopped pion beam we have made a precise measurement of the rare pi(+)-->pi(0)e(+)nu (pi(beta)) decay branching ratio. We have evaluated the branching ratio by normalizing the number of observed pi(beta) decays to the number of observed pi(+)-->e(+)nu (pi(e2)) decays. We find the value of Gamma(pi(+)-->pi(0)e(+)nu)/Gamma(total)=[1.036+/-0.004(stat)+/-0.004(syst)+/-0.003(pi(e2))]x10(-8), where the first uncertainty is statistical, the second systematic, and the third is the pi(e2) branching ratio uncertainty. Our result agrees well with the standard model prediction.
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