Related papers: Kaon experiments at CERN: recent results and prosp…
The NA62 experiment at CERN reports searches for $K^+\to\mu^+N$ and $K^+\to\mu^+\nu X$ decays, where $N$ and $X$ are massive invisible particles, using the 2016-2018 data set. The $N$ particle is assumed to be a heavy neutral lepton, and…
The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A measurement of the…
The ratio $R_K=\frac{\Gamma(K\to e \nu_{e} (\gamma))}{\Gamma(K\to \mu \nu_{\mu} (\gamma))}$ of leptonic decay rates provides a golden probe for testing the structure of the weak interactions because it can be predicted with high accuracy…
The KS->gamma gamma decay rate has been measured with the NA48 detector using a high intensity short neutral beam from the CERN SPS. The measured branching ratio BR(KS->gamma gamma)=(2.78+-0.06(stat)+-0.04(syst))x10-6, obtained from…
Precise measurements of the branching ratios for the $K\to\pi\nu\bar{\nu}$ decays can provide unique constraints on CKM unitarity and, potentially, evidence for new physics. It is important to measure both decay modes,…
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…
The NA48/2 result, based on the data collected during the 2003 run, on direct CP violation in $K^{\pm}\to\pi^{\pm}\pi^0\pi^0$ decay is presented. The main goal of the experiment is to reach a sensitivity at level of $10^{-4}$ in the…
We point out that, given the current experimental status of radiative kaon decays, a subclass of the ${\cal O} (p^4)$ counterterms of the weak chiral lagrangian can be determined in closed form. This involves in a decisive way the decay…
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…
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 $|U_e|^2$…
The first observations of the rare decays KS->pi0e+e- and KS->pi0mu+mu- have been made by the NA48/1 collaboration at the CERN SPS accelerator. From high intensity KS data collected during the 2002 run, clean signals of 7 KS->pi0e+e- events…
The aim of the NA48 experiment at the CERN SPS is to measure direct CP violation in neutral kaon decays thus determining the parameter $\epsilon'/\epsilon$ with an accuracy of $2\times 10^{-4}$. The advantages of NA48 with respect to…
The phenomenology in the neutrino sector requires physics beyond the Standard Model. One possibility is the existence of new massive leptonic states which could be probed at the high intensity machines. The present results on heavy neutral…
The NA48 Collaboration has obtained several new results on kaon and neutral hyperon decays. For hyperons we present new, very precise measurements on the Xi0 lifetime and the decay asymmetries of Xi0 -> Lamda gamma and Xi0 -> Sigma0 gamma.…
A short review of recent results and future prospects in kaon physics is presented. Recent measurements performed at the NA48, NA62, KLOE and KTeV experiments on CP and Lepton Flavour violation and rare decays will be summarised, together…
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…
New results on radiative K+- decays from the NA48/2 experiment are presented. In the channel K+- -> pi+- pi0 gamma more than 1 million decays were reconstructed, leading to the first measurement of the interference between direct photon…
Preliminary results of study of $K^\pm\to3\pi^\pm$ decays by the NA48/2 experiment at CERN SPS are presented. They include a precise measurement of the direct CP violating charge asymmetry of Dalitz plot linear slope parameters…
First preliminary measurement of the direct CP-violating parameter Ag by the NA48/2 experiment at CERN SPS is presented. Using more than 1.6 billions of charged kaon decays into three charged pions, the charge asymmetry in the…
The NA48/2 experiment at the CERN SPS collected in 2003 and 2004 large samples of the decays K+- -> pi+ pi- e+- nu (Ke4+-), K+- -> pi0 pi0 e+- nu (Ke400) and K+- -> pi0 pi0 pi+-. From the Ke4+- form factors and from the cusp in the M00^2…