Related papers: Recent Results from the BNL E787 Experiment
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…
First observations of the rare decays $B^+\rightarrow K^+\pi^+\pi^-\mu^+\mu^-$ and $B^+\rightarrow \phi K^+\mu^+\mu^-$ are presented using data corresponding to an integrated luminosity of $3.0\,{fb}^{-1}$, collected by the LHCb experiment…
Recent results on the kaon rare decays measured in NA48 experiment at CERN are presented.
High statistics data for the K+ -> mu+ nu gamma decay can allow the precision determination of the kaon structure dependent form factors and the kaon polarizability. This study is possible at the proposed FNAL CKM experiment. CKM (Charged…
We report measurements of B meson decays to two kaons using 250/fb of data collected with the Belle detector at the KEKB asymmetric energy e+ e- collider. We find evidence of signals in B+ -> K0(bar) K+ and B0 -> K0 K0(bar) with…
Recent data on B->p pbar K, K0 pi pi and K Kbar K hint at a $\sim 2.3$ GeV object recoiling against a kaon. This could be the narrow state observed in J/\psi -> gamma xi. Nonobservation in p pbar annihilation implies ${\cal B}(\xi \to p\bar…
Recent measurements of kaon decays provide new information about CKM unitarity, lepton universality, and discrete symmetries. KLOE-2, the proposed extension of the kaon physics program at Frascati, will extend the world data set on kaon…
The results and goals of experiments E787, E949, CKM and KOPIO on the measurement of the branching fractions of K+ -> pi+,nu,nubar and K0L -> pi0,nu,nubar are presented.
Results from the study of the rare decays $K^+\to\pi^+\nu\bar{\nu}$, $K^{+}\rightarrow\pi^{+}\mu^{+}\mu^{-}$ and $K^{+}\rightarrow\pi^{+}\gamma\gamma$ at the NA62 experiment at CERN are interpreted in terms of improved limits for…
Experiment E865 at the Brookhaven AGS was set up primarily to search for the lepton flavour violating decay $K^+\to \pi^+\mu^+e^-$ ($K_{\pi\mu e}$) with high sensitivity. The flexibility of the apparatus allowed also to obtain more than an…
We review results on rare and forbidden decays of D^0, D^+, and D^+_s mesons from experiments at FNAL. The decay modes studied have two leptons in the final state and, if observed, would constitute evidence for flavor-changing…
The theoretical status of the rare K --> pi nu nu, KL --> pi0 l+ l- and KL --> mu+ mu- decays in the Standard Model is reviewed. Their sensitivity to New Physics and their discriminating power is also illustrated.
The KTeV experiment has carried out a broad program of studies of rare kaon decays. In this paper we present results on KL -> pi0 gamma gamma, KL -> pi0 e+ e- gamma and KL -> pi0 pi0 gamma. These decays provide a window for testing chiral…
The tau decays to four hadrons have been studied with the CLEO III detector at the Cornell Electron Storage Ring (CESR) using (7.56 +- 0.15) fb^{-1} of data collected near the Y(4S) resonance. We present the first statistically significant…
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…
Recent results from the experiments NA48, NA48/1 and NA48/2 are presented, including: direct CP-violation and Dalitz plot slopes measurements for K+- --> 3 pi decays; pi pi scattering effects in K+- --> pi+- pi0 pi0 and Ke4 decays, as well…
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…
The first search for ultra-rare $K^+$ decays into the $\pi^+e^+e^-e^+e^-$ final state is reported, using a dataset collected by the NA62 experiment at CERN in 2017-2018. An upper limit of $1.4\times 10^{-8}$ at 90% CL is obtained for the…
With usage of the Low theorem the general expression for amplitude of radiative kaon decay \k+ \to \pi+\pi0\gamma is determined.
We report a search for the rare decays B+ to D+ K0 and B+ to D+ K*0 in an event sample of approximately 465 million BBbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find no significant…