Test of Chiral Perturbation Theory with Ke4 Decays at CERN NA48/2 Experiment

The NA48/2 collaboration has accumulated similar to 45,000 semileptonic charged kaon decays to pi(0)pi(0)e(+/-)nu(K-e4(00)), increasing the world available statistics by more than two orders of magnitude. Low background contamination and very good pi(0) reconstruction bring the first precise measurement of the Branching Fraction and decay Form Factor at the percent level. Concurrently, more than one million charged K decays to pi(+)pi(-)e(+/-)nu (K-e4(+-)) have been analyzed, leading to an improved determination of the Branching Fraction by a factor of 3 and detailed Form Factor studies. Comparison of both K-e4 modes decay properties allows a test of chiral symmetry relations and ChPT predictions at unprecedented level.