KLOE measurement of the charged kaon absolute semileptonic BR's

TL;DR

This paper reports precise measurements of the absolute branching ratios for charged kaon semileptonic decays using the KLOE detector, employing a tag technique with a large data sample from the Frascati $ au$-factory.

Contribution

It provides the first precise absolute measurements of charged kaon semileptonic branching ratios using a novel tag technique at the KLOE experiment.

Findings

BR(K$^ ext{e3}$) = 0.04965(38) (stat) (syst)

BR(K$^ ext{μ3}$) = 0.03233(29) (stat) (syst)

Utilized a large data sample of 410 pb$^{-1}$ from the KLOE experiment.

Abstract

This paper is devoted to the measurement of the fully inclusive absolute branching ratios of the charged kaon semileptonic decays, $K^{\pm}\to\pi^0e^\pm\nu(\gamma)$ and $K^\pm \to \pi^0\mu^\pm\nu(\gamma)$. The measurements have been done using a tag technique, employing the two-body decays, $K^\pm \to \mu^\pm\nu$ and $K^\pm \to \pi^\pm\pi^0$, 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 $\phi$-factory. The results obtained are BR(K$^\pm_{e3}$) = $0.04965 (38)_{Stat} (37)_{Syst}$ and BR(K$^\pm_{\mu3}$) = $0.03233 (29)_{Stat} (26)_{Syst}$.