Related papers: Recent KLOE results on kaon physics
The KOTO ($K^0$ at Tokai) experiment aims to observe the CP-violating rare decay $K_L \rightarrow \pi^0 \nu \bar{\nu}$ by using a long-lived neutral-kaon beam produced by the 30 GeV proton beam at the Japan Proton Accelerator Research…
The experimental status of the $K \to \pi \nu \bar{\nu}$ search is presented. The $K \to \pi \nu \bar{\nu}$ decay is sensitive to New Physics because it is theoretically pristine and highly suppressed. The $K_L^0 \to \pi^0 \nu \bar{\nu}$…
The neutral Kaon decays Ks->gamma gamma and Kl->pi0 gamma gamma are very sensitive to higher order loop effects of Chiral Perturbation Theory (ChPT). New measurements of the NA48 experiment show that ChPT contributions of O(p^6) cannot be…
Rare decays of K mesons are reviewed from the perspective of testing the ``ones'' and ``zeros'' of the standard model. Decays K^+ -> pi^+ nu anti-nu and K_L -> pi^0 nu anti-nu probe the one-loop effective Hamiltonian for s -> d nu anti-nu,…
The KLOE experiment has been running since April 1999 at the DAFNE e+e- collider at a center of mass energy centered around the phi meson mass. The luminosity integrated up to September 2002 is about 500 pb-1 . Here we present the…
The NA48/2 and NA62-$R_K$ experiments at the CERN SPS collected large samples of charged kaon decays in flight in 2003--07. The data analysis is still on-going (with over 20 publications produced so far); the recent results from these…
We report the recent results on rare kaon decays from the NA48/2 experiment. The precise measurement of direct photon emission (DE) in the decay K+- -> pi+- pi0 gamma and its interference (INT), with the INT amplitude being observed for the…
In this short presentation I emphasize the increased importance of kaon flavour physics in the search for new physics (NP) that we should witness in the rest of this decade and in the next decade. The main actors will be the branching…
The decay K_L -> pi0 e+ e- is being searched for as a signal of direct Delta S = 1 CP violation. We provide a thorough updating of the analysis of the three components of the decay: 1) Direct CP violation, 2) CP violation through the mass…
The NA62 experiment at CERN has collected a large sample of $K^+$ and $\pi^+$ decays in flight during Run 1 in 2016--2018 and the ongoing Run 2 which started in 2021. Searches for the decays $K^+\rightarrow\pi^+X$ and $\pi^+\rightarrow…
The K_S \to pi+/- e+ e- decay mode has been investigated using the data collected in 2002 by the NA48/1 collaboration. With about 23k signal events and 59k K_L \to pi+ pi- pi0_D normalization decays, the K_S \to pi+ pi- e+ e- branching…
The first dedicated experiment for the rare kaon decay $K^0_L \to \pi^0 \nu \bar{\nu}$ has been performed by the E391a collaboration at the KEK 12-GeV proton synchrotron. A new upper limit of $2.1 \times 10^{-7}$ at the 90% confidence level…
Recent measurements by the NA48 at CERN of selected $K_L$ decays are presented. These are the branching ratios and form factors for channels $K_L\to \pi^{\pm}\pi^0\e^{\mp}\nu_e$ (final result), $K_L\to\pi^{\pm}e^{\mp}\nu_e$ and $K_L\to…
First full next-to-leading order analytical results in Chiral Perturbation Theory for the charged Kaon K -> 3 pi slope g and decay rates CP-violating asymmetries are presented. We discuss the constraints that a measurement of these…
Using the complete KTeV data set of 5241 candidate KL->pi+pi-e+e- decays (including an estimated background of 204+-14 events), we have measured the coupling gCR=0.163+- 0.014(stat)+-0.023(syst) of the CP conserving charge radius process…
In this paper we present the fit to the recent high-statistical KLOE data on the phi -> eta pi^0 gamma decay. This decay mainly goes through the a_0 gamma intermediate state. The obtained results differ from those of the previous fits: data…
We report on a search for the decay Kl -> pi0 e+ e- carried out by the KTeV/E799 experiment at Fermilab. This decay is expected to have a significant CP violating contribution and the measurement of its branching ratio could support the CKM…
In kaon physics, several new precision measurements on flavour variables and CP violation have performed in the recent years. Presented are a new precise determination of the CKM parameter |V_us|, which combines the results of all…
We report on results of a search for the decay mode K_L -> pi^0 gamma e^+ e^- conducted by the E162 experiment at KEK. We observed no events and set a 90% confidence level upper limit of Br(K_L -> pi^0 gamma e^+ e^-)< 7.1x10^{-7} for its…
This letter is the first report of the KL -> pi+- e-+ nu e+ e- decay. Based on 19208+-144 events, we determine the branching fraction, B(KL -> pi+- e-+ nu e+ e-; Mee > 5 MeV/c^2, E*ee > 30 MeV) = (1.285+-0.041)x10^-5, and Gamma(Ke3ee; Mee…