Recent KLOE results on Kaon Physics

Abstract

The KLOE experiment at the DAΦNE φ -factory of the INFN Frascati Laboratory collected data corresponding to 2.5 fb-1 of integrated luminosity. Neutral kaon pairs produced in phi-meson decays offer unique possibilities to perform tests of fundamental discrete symmetries. The entanglement of the two kaons is exploited to search for possible violation of CPT symmetry and Lorentz invariance in the context of the Standard-Model Extension (SME) framework. A new approach to the analysis of φ → KSKL→ π+π−,π+π− events has been adopted allowing us to independently measure all four CPT violating parameters ∆aμ appearing for neutral kaons in the SME. The final KLOE results on ∆aμ will be presented. These are presently the most precise measurements in the quark sector of the SME. We also shortly discuss the perspectives for a new measurement using the KLOE-2 apparatus equipped with a new inner tracker. The measurement of the absolute BR of the K+→ 3π(γ) decay completes the KLOE program of precise and fully inclusive kaon dominant BR measurements. The most recent result, BR(K+→ π+π+π−)=(5.56±0.20)% (Chiang et al.), dates back to more than 30 years ago. We use a normalization sample of events tagged by K→ μν and K→ ππ0 decays and require at least two reconstructed tracks (pion candidates). Finally the number of K→ 3π(γ) decays is counted from the missing mass spectrum of the third pion to extract the branching ratio. The final KLOE result on the BR(K+→ π+π+π−(γ)) is also presented.