Mauro Piccini (University of Perugia)
The NA48/2 collaboration has accumulated ~45000 semi-leptonic K charged decays to pi0 pi0 e+- neutrino (Ke400), increasing the world available statistics by more than two orders of magnitude. Low background contamination and very good pi0 reconstruction bring the first precise measurement of the Branching Fraction and decay Form Factor at the percent level. Concurrently, more than one million K charged decays to pi+ pi- e+- neutrino (Ke4+-) 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 Ke4 modes decay properties allows a test of chiral symmetry relations and ChPT predictions at unprecedented level.
Dr Cristina Lazzeroni (University of Birmingham)