Related papers: The Large-Angle Photon Veto System for the NA62 Ex…
Recent results a future prospects of the NA62 experiment at CERN SPS are presented. The NA62 experiment performed the most precise measurement of the ratio $R_K$ of the $K^+\rightarrow e^\pm\nu$ and K^+\rightarrow \mu^\pm\nu$ decay rates…
The $K_L\to\pi^{\pm}\pi^0e^{\mp}\nu_e(\bar\nu_e)$ decay was investigated with the NA48 detector at CERN SPS using a beam of long-lived neutral kaons. The branching ratio $Br(K_L\to\pi^{\pm}\pi^0e^{\mp}\nu_e(\bar\nu_e))=(5.21\pm…
Meson decays offer a good opportunity to probe new physics. The rare kaon decay $K^+ \rightarrow \pi^+ \nu\bar{\nu}$ is one of the cleanest of them and, for this reason, is rather sensitive to new physics, in particular, vector mediators.…
The decay $K^+\to\pi^+\nu\bar{\nu}$ is highly suppressed in the Standard Model (SM), while its rate can be predicted with minimal theoretical uncertainty. The branching ratio (BR) for this decay is thus a sensitive probe of the flavor…
The NA62 experiment at CERN SPS recorded in 2007 a large sample of $K^+\to\mu^+\nu_\mu$ decays. A peak search in the missing mass spectrum of this decay is performed. In the absence of observed signal, the limits obtained on…
Heavy neutral leptons (HNLs) appear in many extensions of the Standard Model of particle physics. In this study, we investigate to which extent the NA62 experiment at CERN could improve the existing bounds on the HNL mixing angle $|U_e|^2$…
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 NA62 experiment at CERN, configured in beam-dump mode, has searched for dark photon decays in flight to electron-positron pairs using a sample of $1.4\times 10^{17}$ protons on dump collected in 2021. No evidence for a dark photon…
Measuring the rate at which the long-lived, neutral kaon decays into a neutral pion, neutrino, and anti-neutrino allows physicists an opportunity to test precise predictions made by the Standard Model. Differences between theoretical…
A charged-particle veto detector was constructed to study the rare decay $K_{L} \rightarrow \pi^{0} \nu \bar{\nu}$ in the J-PARC K$^{\mathrm{O}}$TO experiment. This detector consists of 3mm-thick plastic scintillator strips and wavelength…
The Outer-Edge Veto (OEV) counter subsystem for extra-photon detection from the backgrounds for the? $K^0_L\rightarrow\pi^0\nu\bar{\nu}$ decay is located at the outer edge of the endcap CsI calorimeter of the KOTO experiment at J-PARC. The…
$K^{+}\rightarrow\pi^{+}\nu\overline{\nu}$ 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…
A sample of 3120 $K^\pm\to\pi^\pm\mu^+\mu^-$ decay candidates with $(3.3\pm0.7)%$ background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a detailed study of the decay properties. The branching ratio…
The NA62 experiment at the CERN SPS aims at measuring the ultra-rare decay $K^+ \to \pi^+ \nu \bar{\nu}$ with 10% accuracy. This can be achieved by detecting about 100 Standard Model events with 10% background in 2-3 years of data taking.…
Searches for violation of lepton flavour universality and lepton number conservation in kaon decays by the NA62 and NA48/2 experiments at CERN, status and future plans of the CERN kaon programme are presented. A precision measurement of the…
The main purpose of the NA62 experiment is to measure the branching ratio of the (ultra) rare decay $K+ \rightarrow {\pi}+{\nu}\bar{\nu}$ with the precision of 10% collecting about 100 events with the Standard Model branching fraction in 3…
The NA62 experiment at CERN targets the measurement of the ultra-rare $K^{+} \to \pi^{+}\nu\bar{\nu}$ decay, and carries out a broad physics programme that includes probes for symmetry violations and searches for exotic particles. Data were…
From the 2002 data taking with a neutral kaon beam extracted from the CERN-SPS, the NA48/1 experiment observed 97 $\Xi^{0}\rightarrow \Sigma^{+} \mu^{-} \bar{\nu}_{\mu}$ candidates with a background contamination of $30.8 \pm 4.2$ events.…
The NA62 experiment at CERN reports a search for the lepton number violating decays $K^+\to\pi^-e^+e^+$ and $K^+\to\pi^-\mu^+\mu^+$ using a data sample collected in 2017. No signals are observed, and upper limits on the branching fractions…
We have performed a search for the K$^{0}_{L} \rightarrow \pi^{0}\nu\bar{\nu}$ decay with the KOTO detector at J-PARC. The KOTO detector was designed to observe the decay and measure its branching ratio (BR). Focusing on this golden decay…