Related papers: Kaon-Scatter Introduced Backgrounds in the KOTO Ex…
A search for the massless dark photon in the decay $K^{+}\to \pi^{+}\pi^{0}\overline{{} \gamma}$ is performed with the OKA detector exposed to 17.7 GeV/c RF separated secondary beam of the U70 Proton Synchrotron. A high-statistics data…
The neutral-kaon system constitutes a fantastic and unique laboratory for the study of CPT symmetry and the basic principles of quantum mechanics, and a $\phi$-factory represents a unique opportunity to push forward these studies. The…
We evaluate the rare radiative kaon decays K_{L,S} -> 3 gamma. Applying the requirements of gauge invariance and Bose symmetry, we derive a general form of the decay amplitude, including both parity-conserving and parity-violating…
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…
T2K is a long baseline high intensity neutrino oscillation experiment employing an off-axis design to search for the as yet unobserved appearance of \nu_e neutrinos in a \nu_{\mu} beam. The neutrino beam originates at the J-PARC facility in…
A high statistics data sample of the decays of $K^+$ mesons to three charged particles was accumulated by the OKA experiment in 2012 and 2013. This allowed to select a clean sample of about 450 events with…
The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminium nucleus ($\mu-e$…
The ratio $\mathcal{B}(K_L\to\pi^0\nu\bar\nu)/\mathcal{B}(K^+\to\pi^+\nu\bar\nu)$ of the branching fractions of kaon decays $K_L\to\pi^0\nu\bar\nu$ and $K^+\to\pi^+\nu\bar\nu$ has a maximum of about 4.3 under the assumption that the…
In this short presentation I emphasize the increased importance of kaon flavour physics in the search for new physics (NP) that we should witness in the rest of this decade and in the next decade. The main actors will be the branching…
Kaon physics can test new-physics effects in leptonic or semileptonic decays. A unitarity test of the first row of the CKM mixing matrix is obtained from the precision measurements of Kl3 widths for K{\pm}, KL, and (unique to KLOE) KS. The…
We review some recent theoretical results on rare kaon decays. Particular attention is devoted to find Standard Model tests. This is theoretically easy in $K\to \pi \nu \bar{\nu}$, while a careful study of the long distance contributions is…
We discuss weak kaon decays in a scenario in which the Standard Model is extended by massive sterile fermions. After revisiting the analytical expressions for leptonic and semileptonic decays we derive the expressions for decay rates with…
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 importance of rare $K$ decays especially in the context of a kaon unitarity triangle (KUT) is emphasized. The decay $K_L \to \pi^0 \nu \bar \nu$ is theoretically very clean but experimentally extremely challenging. The Standard Model…
We study the (K-,p) reaction on nuclei with a 1 GeV/c momentum kaon beam, paying a special attention at the region of emitted protons having kinetic energy above 600 MeV, which was used to claim a deeply attractive kaon nucleus optical…
This work concerned two experimental searches for the violation of fundamental discrete symmetries in physical systems originating from electron-positron interactions. The first study was a direct test of the symmetry under reversal in time…
Forbidden in the Standard Model, Charged Lepton Flavour Violation is a strong probe for New Physics. The COMET Experiment will measure one of these processes: that of COherent Muon to Electron Transitions, where a muon converts to an…
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…
A charged-particle veto detector was constructed to study the rare decay $K_{L} \rightarrow \pi^{0} \nu \bar{\nu}$ in the J-PARC K$^{\mathrm{O}}$TO experiment. This detector consists of 3mm-thick plastic scintillator strips and wavelength…
This paper reports the recent progress made in developing a spiral fiber tracker (SFT) for use in the E36 experiment scheduled at the Japan Proton Accelerator Research Complex (J-PARC). The primary goal of this positive kaon decay…