Paper detail

KLOE measurement of the charged kaon absolute semileptonic BR's

This paper is devoted to the measurement of the fully inclusive absolute branching ratios of the charged kaon semileptonic decays, $K^{\pm}\toπ^0e^\pmν(γ)$ and $K^\pm \to π^0μ^\pmν(γ)$. The measurements have been done using a tag technique, employing the two-body decays, $K^\pm \to μ^\pmν$ and $K^\pm \to π^\pmπ^0$, and using a sample of about 410 pb$^{-1}$ collected during the 2001 and 2002 data taking of the KLOE experiment at Daphne, the Frascati $ϕ$-factory. The results obtained are BR(K$^\pm_{e3}$) = $0.04965 (38)_{Stat} (37)_{Syst}$ and BR(K$^\pm_{\mu3}$) = $0.03233 (29)_{Stat} (26)_{Syst}$.