Related papers: Rare Kaon Decays
The NA62 experiment at the CERN SPS aims to measure the branching ratio of the rare decay $K^+\to\pi^+\nu\bar\nu$ with a relative precision of $\sim10%$. To achieve that goal, it is designed to be exposed to $1.2\times 10^{13}$ $K^+$ decays…
The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay $K^+ \to \pi^+ \nu \bar{ \nu }$, using the decay in flight of kaons in an unseparated beam with…
The first search for the rare kaon decay $\kppnn$ has been performed by the E391a collaboration at the KEK 12-GeV proton synchrotron. An upper limit of $4.7\times10^{-5}$ at the 90 % confidence level was set for the branching ratio of the…
The KOTO experiment recently reported four candidate events in the signal region of $K_L\to \pi^0 \nu\bar\nu$ search, where the standard model only expects $0.10\pm 0.02$ events. If confirmed, this requires physics beyond the standard model…
Rare kaon decays provide unique opportunity to test the Standard Model and probe its possible extensions. The final result on the lepton universality test by measuring the ratio R_K = G(K+- to e+- nu)/G(K+- to mu+- nu) is presented as well…
The KOTO experiment aims to discover the rare decay $K^{0}_{L}\rightarrow \pi^{0} \nu \bar{\nu}$ at J-PARC. This mode breaks the CP symmetry directly and is highly suppressed in the Standard Model. Thus the mode is sensitive to new physics,…
Precision measurements of the branching ratios (BRs) for rare kaon decays can provide unique constraints on CKM unitarity and may reveal the existence of new physics. The BRs for two of these decays, $K^+\to\pi^+\nu\bar{\nu}$ and…
$K\rightarrow \pi\nu \bar\nu$ is one of the theoretically cleanest meson decay where to look for indirect effects of new physics complementary to LHC searches. The NA62 experiment at CERN SPS is designed to measure the branching ratio of…
The $K\to\pi\nu\bar{\nu}$ ultra-rare decays are precisely computed in the Standard Model (SM) and are ideal probes for physics beyond the SM. The NA62 experiment at the CERN SPS is designed to measure the charged channel with a precision of…
NA62, an experiment at the CERN SPS to measure the branching ratio for the decay K+ -> pi+ nu nu-bar with ~10% precision, will observe ~10^13 K+ decays in its fiducial volume, and will thus also be able to carry out a rich program to search…
The Grossman-Nir bound concept is robust, but the common perception of $K_L \to \pi^0\nu\bar\nu < 1.4 \times 10^{-9}$ may be circumvented. Because of the blinding $K\pi2$(3) decay, $K^+$ decay experiments such as E787/E949 and the currently…
The CERN NA62 experiment uses a novel "kaon decay-in-flight" technique to observe $K^+ \to \pi^+ \nu \overline{\nu}$. The preliminary result based on the analysis of the full 2016 dataset will be presented. In agreement with the Standard…
The KOTO II experiment is proposed to measure the branching ratio of the decay $K_L\to\pi^0\nu\bar{\nu}$ at J-PARC. With a beamline to extract long-lived neutral kaons at 5 degrees from a production target, the single event sensitivity of…
NA62 is a fixed-target kaon experiment at the CERN SPS. The recent measurement of the ultra-rare decay $K^+\to\pi^+\nu\bar\nu$, based on data collected between 2016 and 2024 is reported. The measurement is compatible with previous…
Searches for lepton flavour violation and lepton number violation in kaon decays by the NA62 and NA48/2 experiments at CERN are presented. A new measurement of the ratio of charged kaon leptonic decay rates…
The perspectives of a search for the rare decay $K_L\to\pi^0\nu\bar{\nu}$ at a Phi-factory are discussed. After a general analysis, we focus on the realistic case of KLOE and DAFNE, showing that limits of the order of $10^{-9}$ on…
The NA62 experiment reports an investigation of the $K^+\rightarrow\pi^+\nu\bar{\nu}$ mode from a sample of $K^+$ decays collected in 2017 at the CERN SPS. The experiment has achieved a single event sensitivity of $(0.389\pm…
A decade long search for the rare kaon decay to pi^+nunu-bar has been pursued by E787. Two signal events are observed, giving a measurement of the branching ratio Br(K^+ -> PI^+NUNU-BAR)=1.57^+1.75_-0.82 x 10^-10 and a constraint on the…
Rare kaon decays offer a powerful tool for investigating new physics in $s\to d$ transitions. Currently, many of the interesting decay modes are either measured with rather large uncertainties compared to their theoretical predictions or…
The KOTO experiment is a particle physics experiment located in J-PARC, Japan, aiming to explore physics beyond the Standard Model by measuring the branching ratio of the $K_L\rightarrow\pi^{0}\nu\bar{\nu}$ decay. This decay has not yet…