相关论文: Experimental Status of K -> pi nu nu_bar
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…
Three events for the decay K+ => pi+,nu,nubar have been observed in the pion momentum region below the K+ => pi+,pi0 peak, 140 < P_pi < 199 MeV/c, with an estimated background of 0.93+-0.17(stat.)+0.32-0.24(syst.) events. Combining this…
The NA62 experiment reports the branching ratio measurement BR$(K^+ \rightarrow \pi^+ \nu\bar{\nu}) = (10.6^{+4.0}_{-3.4} |_{\rm stat} \pm 0.9_{\rm syst}) \times 10 ^{-11}$ at 68% CL, based on the observation of 20 signal candidates with an…
This paper presents the latest results from experiment E787, at Brookhaven National Laboratory, on K+ -> pi nu/nubar and radiative K+ decays. The result for K+ -> pi nu/nubar uses data collected in runs taken during 1995, 1996 and 1997. In…
The availability of high intensity kaon beams at the CERN SPS North Area gives rise to unique possibilities for sensitive tests of the Standard Model in the quark flavor sector. Precise measurements of the branching ratios for the…
There is no doubt that in the coming years we will witness the renaissance of kaon flavour physics with crucial measurements of the branching ratios for the rare decays $K^+\rightarrow\pi^+\nu\bar\nu$ and $K_{L}\rightarrow\pi^0\nu\bar\nu$…
The availability of high-intensity kaon beams at the J-PARC Hadron Experimental Facility and the CERN SPS North Area, together with the abundant forward production of kaons at the LHC, gives rise to unique possibilities for sensitive tests…
The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay KL->e+e-mu+mu-, with an estimated background of 0.8 events. The branching ratio of this mode is determined to be 2.69 +/- 0.24 (stat) +/- 0.12 (syst) x…
The NA62 experiment at CERN SPS aims to measure the branching ratio of the ultra-rare kaon decay $K^+\to\pi^+\nu\bar{\nu}$ with 10\% precision, collecting $\sim 100$ events, assuming the Standard Model~(SM) branching ratio of $8.4 \times…
We review the current status of the field of rare kaon decays. The study of rare kaon decays has played a key role in the development of the standard model, and the field continues to have significant impact. The two areas of greatest…
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…
Rare kaon decays via Flavor Changing Neutral Currents are discussed in the context of the CKM unitarity triangle with a particular interest in the rare kaon decays K^+ --> pi^+ nu nubar and K^0_L --> pi^0 nu nubar. New results and the…
The branching ratio of the rare decay pi0 -> e+ e- has been measured precisely, using the complete data set from the KTeV E799-II experiment at Fermilab. We observe 794 candidate pi0 -> e+ e- events using K0_L -> 3pi0 as a source of tagged…
The NA62 experiment at CERN will measure the branching ratio of the K+ -> pi+ nu nubar decay with a precision of 10%, collecting about 100 events in two years of run. This paper will review the design of the experiment, the strategy for the…
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…
One-prong tau decays into final states involving kaons are studied with about 161k tau+tau- events collected by the ALEPH detector from 1991 to 1995. Charged kaons are identified by dE/dx measurement, while K0L's are detected through their…
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…
We study the rare kaon decays in the framework of general SUSY models. Unlike the results in the literature, we find the contributions from the gluino exchange to the branching ratio of $K^+\to \pi^+ \nu \bar{\nu}$ can reach the central…
A search for the decay K_S -> pi^0mu^+mu^- has been made by the NA48/1 Collaboration at the CERN SPS accelerator. The data were collected during 2002 with a high-intensity K_S beam. Six events were found with a background expectation of…
We present an extensive analysis of rare K decays, in particular of the two neutrino modes K+->pi+ nu nu-bar and KL->pi0 nu nu-bar, in the Minimal Supersymmetric extension of the Standard Model. We analyse the expectations for the branching…