Observation of the rare decay Ks->pi0e+e-

Abstract

A search for the decay Ks->pi0e+e- has been made by the NA48/1 experiment at the CERN SPS accelerator. Using data collected during 89 days in 2002 with a high-intensity Ks beam, 7 events were found with a background of 0.15 events. The branching fraction BR(Ks->pi0e+e-, m(ee) > 0.165 GeV/c^2) = (3.0^{+1.5}_{-1.2}(stat) +/-0.2 (syst)) x 10^{-9} has been measured. Using a vector matrix element and a form factor equal to one, the measurement gives BR(Ks->pi0e+e-) = (5.8^{+2.9}_{-2.4}) x 10^{-9}.

15 pages, 7 figures. Accepted for publication in Physics Letters B

References in corpus (9)

• A Unified Approach to the Classical Statistical Analysis of Small Signals
• A precision measurement of direct CP violation in the decay of neutral kaons into two pions
• The Decays $K\to \pi {\ell }^{+}{\ell }^{-}$ beyond Leading Order in the Chiral Expansion
• Extracting short-distance physics from K_{L,S} -> pi0 e+ e- decays
• A new measurement of the properties of the rare decay K -> pi+ e+ e-
• Precise measurement of the decay $K_L\to {\pi }^0\gamma \gamma$
• Measurement of the Decay KL -> Pi0 Gamma Gamma
• Search for the Decay Kl -> pi0 e+ e-
• Rare decays: theory vs. experiments

Cited by in corpus (27)

• Kaon Decays in the Standard Model
• Physics with the KLOE-2 experiment at the upgraded DA$\varphi$NE
• Flavor Physics in the Randall-Sundrum Model: II. Tree-Level Weak-Interaction Processes
• Search for the Rare Decay KL --> pi0 ee
• B, D and K decays
• KL to pi0 e+ e- and KL to pi0 mu+ mu- : A binary star on the stage of flavor physics
• Rare Kaon Decays Revisited
• Lepton flavor (universality) violation in rare kaon decays
• Exploring the flavour structure of the MSSM with rare K decays
• Combined Constraints on First Generation Leptoquarks
• Experiments with K-Meson Decays
• Final Results from the KTeV Experiment on the Decay KL -> pi0 gamma gamma
• Observation of the rare decay K_S -> pi^0mu^+mu^-
• First exploratory calculation of the long-distance contributions to the rare kaon decays $K\to \pi {\ell }^{+}{\ell }^{-}$
• Prospects for a lattice computation of rare kaon decay amplitudes: $K\to \pi {\ell }^{+}{\ell }^{-}$ decays
• Signals of the QCD axion with mass of 17 MeV/c^2: nuclear transitions and light meson decays
• Radiative corrections in K --> pi l+ l- decays
• The s ---> d gamma decay in and beyond the Standard Model
• $K\to \pi {\ell }^{+}{\ell }^{-}$ form factor in the Large-N${}_c$ and cut-off regularization method
• Closing in on the radiative weak chiral couplings
• First observation of the KS->pi0 gamma gamma decay
• Theory review on rare K decays: Standard Model and beyond
• ${\Sigma }^{+}\to p{\ell }^{+}{\ell }^{-}$ decays within the standard model and beyond
• Prospects for kaon physics at LHCb
• New Physics Searches at Kaon and Hyperon Factories
• On the electron-positron energy asymmetry in K_L --> pi0 e+ e-
• Chiral Phenomenological Relations between Rates of Rare Radiative Decay of Kaon to Pion and leptons and the meson Formfactors