Kaon physics can test new-physics effects in leptonic or semileptonic decays. A unitarity test of the first row of the CKM mixing matrix is obtained from the precision measurements of Kl3 widths for K{pm}, KL, and (unique to KLOE) KS. The KLOE measur
ement of RK = {Gamma}(Ke2)/{Gamma}(K{mu}2) with an accuracy at the % level, aims at finding evidence of deviations from the SM prediction induced by lepton-flavor violation new-physics effects.
We present a precise measurement of the ratio R_K = Gamma(Ke2(gamma))/Gamma(Kmu2(gamma)) performed with the KLOE detector. The results are based on data collected at the Frascati e^+e^- collider DAFNE for an integrated luminosity of 2.2 fb^{-1}. We f
ind R_K = (2.493pm0.025_{stat}pm0.019_{syst})times 10^{-5}, in agreement with the Standard Model expectation. This result is used to improve constraints on parameters of the Minimal Supersymmetric Standard Model with lepton flavor violation.
This paper is devoted to the first analyses based on the complete data sample collected by the KLOE detector at DAPHNE, the Frascati phi-factory. The result for the BR(K_S -> gammagamma) and the search for the decay K_S->e+e- are presented. Particula
r emphasis is put on the measurement of the ratio of Ke2 and Kmu2 BRs.
This paper is devoted to the measurement of the fully inclusive absolute branching ratios of the charged kaon semileptonic decays, $K^{pm}topi^0e^pm u(gamma)$ and $K^pm to pi^0mu^pm u(gamma)$. The measurements have been done using a tag technique, em
ploying the two-body decays, $K^pm to mu^pm u$ and $K^pm to pi^pmpi^0$, 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$^pm_{mu3}$) = $0.03233 (29)_{Stat} (26)_{Syst}$.
