Kaon physics at kloe

The KLOE experiment1 at DAΦNE the Frascati φ factory, allows the extensive study of K mesons which have represented, since their discovery, one of the most powerful sources of information on fundamental interactions. Neutral kaons provide one of the most sensitive system to the violation of CP and CPT symmetries and to possible deviations from Quantum Mechanics. The semileptonic decays of neutral and charged kaons give the most precise determination of Vus · KLOE can measure all the experimental inputs to Vus for both neutral and charged kaons. Preliminary results for BR(K± → π0e ±v) and BR(K± -→ π0μ ±v), and for the K± lifetime T± are presented, together with the measurements of the branching ratios for K Le3 and KLμ3, Kse3 decays, the KL lifetime τL, and the KLe3 form factors. The measurement of Vus is presented together with the value of V us/Vud obtained from the measurement of the fully inclusive Kμ 2+(γ) absolute branching ratio. The BR(KL → π+π-) and the related CP violating parameter ∈ are presented, together with the CPT violating parameters obtained using the Bell-Steinberger relation.