相关论文: Rare kaon decays (NA48/2 and NA62)
The NA48/2 Collaboration at CERN has accumulated and analysed unprecedented statistics of rare kaon decays in the $K_{e4}$ modes: $K_{e4}(+-)$ ($K^\pm \to \pi^+ \pi^- e^\pm \nu$) and $K_{e4}(00)$ ($K^\pm \to \pi^0 \pi^0 e^\pm \nu$) with…
The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay $K^\pm\to\pi^\pm\gamma\gamma$ from these data sets based on…
A study of the dynamics of the rare decay $K^\pm\to\pi^\pm\gamma\gamma$ has been performed on a sample of 232 decay candidates, with an estimated background of $17.4\pm1.1$ events, collected by the NA62 experiment at CERN in 2007. The…
Recent NA48 results from detailed studies of $K_{L,S}\to \pi^+ \pi^- e^+ e^-$ and $K_S\to\pi^0 \gamma\gamma$ decay modes are presented. The results are based on the data collected with the NA48 detector at the CERN SPS during the 1998-199 9…
The NA48/2 Collaboration at CERN has accumulated unprecedented statistics of rare kaon decays in the Ke4 modes: Ke4(+-) ($K^\pm \to \pi^+ \pi^- e^\pm \nu$) and Ke4(00) ($K^\pm \to \pi^0 \pi^0 e^\pm \nu$) with nearly one percent background…
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…
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…
Recent results on the kaon rare decays measured in NA48 experiment at CERN are presented.
Recent results from the NA48/1 and NA48/2 experiments at the CERN SPS are presented. NA48/2 carried out data taking in 2003 and 2004 collecting charged kaon decays: branching ratios and form factors have been measured for the rare K+- to…
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…
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…
The rare decays $\mathrm{K}^+\to \pi^+ \nu \bar{\nu}$ and $\mathrm{K_L}\to \pi^0 \nu \bar{\nu}$ are extremely attractive processes to study flavor physics because they are both exceptionally clean from a theoretical point of view. These…
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 NA48/2 experiment at the CERN SPS carried out data taking in 2003 and 2004. Analysis of the selected data samples of 7,146 $K^\pm\to\pi^\pm e^+e^-$ decay candidates with 0.6% background, 1,164 $K^\pm\to\pi^\pm\gamma\gamma$ candidates…
The Kaon physics program at CERN will be shortly presented, addressing the most recent results from the NA48/2 and NA62 experiments at the CERN SPS and future prospects.
The ratio $R_K = \Gamma(K^{\pm}\to e^{\pm}\nu(\gamma)) / \Gamma(K^{\pm}\to\mu^{\pm}\nu(\gamma))$ provides a powerful probe of the structure of weak interactions. It is calculated with very high precision within the Standard Model, but…
NA62 is a fixed target kaon experiment at the CERN SPS which aims at measuring the branching ratio of the $K^+\to\pi^+\nu\bar{\nu}$ decay with 10% precision. This ultra-rare kaon decay is theoretically extremely clean and an ideal place to…
The main physics goal of the NA62 experiment at CERN is to precisely measure the branching ratio of the kaon rare decay $K^+\rightarrow \pi^+ \nu \bar\nu$. This decay is strongly suppressed in the Standard Model and its branching ratio is…