相关论文: Ke4 decays and Wigner cusp

We report here a measurement of form factors of $K^{\pm}_{\mu 3}$ decay by the NA48/2 experiment at CERN. Using a sample of 3.4$\times10^6$ events we provide preliminary form factor values according to various parametrizations. The slope of…

A large low-background sample of events (10300) has been collected for the rare decay of kaons in flight K+ -> pi+ e+ e- by experiment E865 at the Brookhaven AGS. The decay products were accepted by a broad band high-resolution charged…

We discuss the recent Cabibbo's proposal to measure the pion-pion scattering lengths combination a0-a2 from the cusp effect in the pi0-pi0 energy spectrum at threshold for K+ to (pi0 pi0 pi+) and KL to (pi0 pi0 pi0). We estimate the…

The decay $K^{-} \to \mu^{-} \bar{\nu} \pi^{0}$ has been studied using in-flight decays detected with ``ISTRA+'' setup operating in the 25 GeV negative secondary beam of the U-70 PS. About 112K events were used for the analysis. The…

The first search for the decay K^+ -> pi^+ pi^0 nu nubar has been performed with the E787 detector at BNL. Based on zero events observed in the kinematical search region defined by 90 MeV/c < P_{pi^+} < 188 MeV/c and 135 MeV < E_{pi^0} <…

The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003--2004. A new upper limit on the rate of the lepton number violating decay…

The NA62 experiment, proposed to measure the very rare decay K+ to pi+ nu nubar at the CERN SPS with 10% accuracy, aims to collect about 80 events in two years of data taking, keeping background contamination lower than 10%. This paper…

Using data taken during the year 2000 with the NA48 detector at the CERN SPS, a search for the CP violating decay K_S -> 3 pi0 has been performed. From a fit to the lifetime distribution of about 4.9 million reconstructed K0/K0bar -> 3 pi0…

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…

The NA62 experiment at the CERN SPS reports the first search for $K^+ \rightarrow \pi^+ \nu \bar{\nu}$ using the decay-in-flight technique, based on a sample of $1.21\times10^{11}$ $K^+$ decays collected in 2016. The single event…

Using 214 fb-1 of data recorded by the Babar detector at the PEPII electron-positron collider, we study the decay Ds+ --> K+ K- e+ nu. Except for a small S-wave contribution, the events with K+K- masses in the range 1.01-1.03 GeV/c2…

The anomaly (cusp) in the mass spectrum of two neutral pions from the three-pion decays of charged kaon has been observed in the NA48/2 experiment. Using the recently developed interpretation of this effect in terms of Chiral Perturbative…

The experimental determination of low energy pi K scattering phase shifts would assist in determining scattering lengths as well as low energy constants of chiral perturbation theory for which sum rules have been constructed. The FOCUS…

We present measurements of branching fractions and CP-violating asymmetries for neutral B meson decays to two-body final states of charged pions and kaons based on a sample of about 88 million Y(4S)-->BB decays. From a time-independent fit…

An effective theory of large N_{C} QCD of mesons has been used to study six K_{l4} decay modes. It has been found that the matrix elements of the axial-vector current dominate the K_{l4} decays. PCAC is satisfied. A relationship between…

We report improved measurements of branching fractions for B -> K pi and B -> pi pi decays based on a data sample of 449 million B Bbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB e^+e^- collider. We…

Using data collected with the HyperCP (E871) spectrometer during the 1997 fixed-target run at Fermilab, we report the first observation of the decay K- -> pi- mu+ mu- and new measurements of the branching ratios for K+/- -> pi+/- mu+ mu- .…

The decay rate of $\klpgg$ has been measured with the NA48 detector at the CERN SPS. A total of 2558 $\klpgg$ candidates have been observed with a residual background of 3.2%. The branching ratio is determined to be $(1.36 \pm0.03_{(stat)}…

$\chi_{c0}$, $\chi_{c1}$, and $\chi_{c2}$ decays to $\pi^+\pi^-K^0_SK^0_S$ and $K^+K^-K^0_SK^0_S$, as well as $\psi(2S)$ decay to $\pi^+\pi^-K^0_SK^0_S$ are presented. The branching fractions of these decay channels are determined using…

In this paper, radiative decays $\rho^0 \to \pi^+\pi^-\gamma, \pi^0\pi^0\gamma$ ,$\phi \to K^+K^-\gamma, K^0 \bar{K^0}\gamma$ are studied systematically in the U(3)$_L\timesU(3)_R$ chiral theory of mesons. The theoretical differential…