Related papers: Precision test of the SM with Kl2 and Kl3 decays a…
Recent results and future prospects of rare kaon-decay experiments at KEK, BNL, CERN and FNAL are reviewed. Topics include lepton flavor violation, T-violating transverse muon polarization in K+{mu3}, exotic decays, K0 -> pi0 ell+ ell-, and…
Based on a data sample of 60 pb$^{-1}$ collected at the $\psi(3770)$ resonance with the CLEO-c detector at CESR, we present improved measurements of absolute branching fractions for exclusive $D^0$ semileptonic decays into $K^-e^+\nu$,…
The complementarity between the quark and lepton mixing matrices is shown to provide robust predictions. We obtain these predictions by first showing that the matrix V_M, product of the quark (CKM) and lepton (PMNS) mixing matrices, may…
It has been pointed out that supersymmetric extensions of the Standard Model can induce significant changes to the theoretical prediction of the ratio $\Gamma(K\rightarrow e\nu)/\Gamma (K\rightarrow\mu\nu)\equiv R_{K}$, through lepton…
The KOTO experiment was designed to observe and study the K$^{0}_{L} \rightarrow$ $\pi^{0}\nu\bar{\nu}$ decay at J-PARC. The Standard Model (SM) prediction for the process is (3.0 $\pm$ 0.3) x 10$^{-11}$ with small uncertainties. This…
In the past few years charged kaon experiments have indicated possible scalar and tensor couplings in semileptonic kaon decays(K --> pi e nu). These couplings, if correct, are not predicted by the Standard Model and may indicate the onset…
The quantity R_K = Gamma(K -> e nu)/Gamma(K -> mu nu) studied by the experiment NA62 at CERN is known to probe lepton-flavour violating (LFV) parameters of the Minimal Supersymmetric Standard Model (MSSM). A non-zero parameter…
The neutral-kaon system constitutes a fantastic and unique laboratory for the study of CPT symmetry and the basic principles of quantum mechanics, and a $\phi$-factory represents a unique opportunity to push forward these studies. The…
Neutrino oscillations as suggested by the recent Super-Kamiokande result imply that lepton numbers could be violated, and Z$\to \mu^{\mp} +\tau^{\pm}$ is a typical manifestation. We point out that for this mode, the GIM cancelation is much…
We provide general effective-theory arguments relating present-day discrepancies in semi-leptonic $B$-meson decays to signals in kaon physics, in particular lepton-flavour violating ones of the kind $K \to (\pi) e^\pm \mu^\mp$. We show that…
Using a technique that is not subject to first-order SU(3) symmetry breaking effects, we determine the $V_{us}$ element of the CKM matrix from data on semileptonic hyperon decays. We obtain $V_{us}$ =0.2250(27). This value is of similar…
We introduce a new method to search for the lepton-flavor violating Higgs decays $h\rightarrow\tau\mu$ and $h\rightarrow\tau e$ in the leptonic $\tau$ decay channel. In particular, the Standard Model background is estimated in a fully data…
Based on a sample of 300 million $K_S$ mesons produced in $\phi \to K_L K_S$ decays recorded by the KLOE experiment at the DA$\Phi$NE $e^+e^-$ collider we have measured the branching fraction for the decay $K_S \to \pi \mu \nu$. The $K_S$…
We present measurements of the flavor-changing neutral current decays B --> Kl+l- and B --> K*l+l-, where l+l- is either an e+e- or mu+mu- pair. The data sample comprises 229 x 10^6 Y(4s) -->to BBbar decays collected with the BaBar detector…
High precision electroweak tests, such as deviations from the Standard Model expectations of the Lepton Flavor Universality breaking in K->lnu (with l= e or mu), represent a powerful tool to test the Standard Model and, hence, to constrain…
The K^+ \to \pi^0 \mu^+ \nu \gamma ($K_{\mu 3 \gamma}$) decay has been measured with stopped positive kaons at the KEK 12 GeV proton synchrotron. A $K_{\mu 3 \gamma}$ sample containing 125 events was obtained. The partial branching ratio…
Measurement of the CKM phase gamma in B->DK decays can be potentially performed with high precision due to low theoretical uncertainties. However, the precision measurement requires very large experimental samples of B decays. This report…
The ratio of the $K^{+}\to \pi^{0} \mu^{+} \nu$ ($K_{\mu3}^+$) and $K^{+}\to \pi^{0} e^{+} \nu$ ($K_{e3}^+$) decay widths, $\Gamma(K_{\mu 3})/\Gamma(K_{e3})$, has been measured with stopped positive kaons. $K_{\mu3}^+$ and $K_{e3}^+$…
The decay rate of $\klpgg$ has been measured with the NA48 detector at the CERN SPS. A total of 2558 $\klpgg$ candidates have been observed with a residual background of 3.2%. The branching ratio is determined to be $(1.36 \pm0.03_{(stat)}…
Recent results from the NA48/2 and NA62 kaon decay-in-flight experiments at CERN are presented. A precision measurement of the helicity-suppressed ratio RK of the K+- to e+- nu and K+- to mu+- nu decay rates has been performed using the…