Mode | Fraction ($\Gamma_i$ / $\Gamma$) | Scale Factor/ Conf. Level |
P(MeV/c) | |||
$\Gamma_{1}$ | ${{\mathit \pi}^{+}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}$ | $0.9998770$ $\pm0.0000004$ | 30 |
Note: | Measurements of $\Gamma $( ${{\mathit e}^{+}}{{\mathit \nu}_{{e}}}$ )/$\Gamma $( ${{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}$ ) always include decays with ${{\mathit \gamma}}$'s, and measurements of $\Gamma $( ${{\mathit e}^{+}}{{\mathit \nu}_{{e}}}{{\mathit \gamma}}$ ) and $\Gamma $( ${{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}{{\mathit \gamma}}$ ) never include low-energy ${{\mathit \gamma}}$'s. Therefore, since no clean separation is possible, we consider the modes with ${{\mathit \gamma}}$'s to be subreactions of the modes without them, and let [$\Gamma $( ${{\mathit e}^{+}}{{\mathit \nu}_{{e}}}$ ) $+$ $\Gamma $( ${{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}$ )]/$\Gamma _{{\mathrm {total}}}$ = 100$\%$. |
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