Status of the measurement of KS → πeν branching ratio and lepton charge asymmetry with the KLOE detector

Abstract

We present the current status of the analysis of about 1.7 billion KS KL pair events collected at DAΦNE with the KLOE detector to determine the branching ratio of KS → πeν decay and the lepton charge asymmetry. This sample is ∼ 4 times larger in statistics than the one used in the previous most precise result, from KLOE as well, allowing us to improve the accuracy on the measurement and related tests of CPT symmetry and ∆S = ∆Q rule.