A new limit of T-violating transverse muon polarization in the   $K^{+}\to\pi^{0}\mu^{+} \nu$ decay
  A search for T-violating transverse muon polarization ($P_T$) in the $K^{+}\to \pi^{0}\mu^{+}\nu$ decay was performed using kaon decays at rest. A new improved value, $P_T= -0.0017\pm 0.0023 (stat)\pm 0.0011 (syst)$, was obtained giving an upper limit, $| P_T | < 0.0050$. The T-violation parameter was determined to be Im$\xi = -0.0053 \pm 0.0071(stat)\pm 0.0036(syst)$ giving an upper limit, $|$Im$\xi| <0.016$. 
M. Abe, M. Aliev, V. Anisimovsky, M. Aoki, Y. Asano, T. Baker, M.   Blecher, P. Depommier, M. Hasinoff, K. Horie, Y. Igarash...