New Limit on T-violating Parameters in Kaon Decays

Abstract

A search for a T-violating transverse muon polarization (PT ) in K+ ? p0µ+? decay was carried out in the experiment E246 at the KEK-PS. The Standard model (SM) predicts vanishing value of the polarization (< 10-7), so an observation of non-zero PT at the current experimental sensitivity level would be a definite signature of new physics beyond SM. The preliminary result of the analysis of the 1996-1998 data is presented here: PT = (-3.3±3.7(stat)±0.9(syst))×10-3, which corresponds to the T-violation parameter Im(?) = (-0.9 ± 1.2(stat) ± 0.3(syst)) × 10-2. There is no evidence for T-violation in Kµ3 at the current level of sensitivity.