# Im($\eta _{+−0}$) = Im(A( ${{\boldsymbol K}_S^0}$ $\rightarrow$ ${{\boldsymbol \pi}^{+}}{{\boldsymbol \pi}^{-}}{{\boldsymbol \pi}^{0}}$ , $\boldsymbol CP$-violating) $/$ A( ${{\boldsymbol K}_L^0}$ $\rightarrow$ ${{\boldsymbol \pi}^{+}}{{\boldsymbol \pi}^{-}}{{\boldsymbol \pi}^{0}}$ )) INSPIRE search

VALUE EVTS DOCUMENT ID TECN  COMMENT
$-0.002$ $\pm0.009$ ${}^{+0.002}_{-0.001}$ 500k 1
 1997 B
CPLR
• • • We do not use the following data for averages, fits, limits, etc. • • •
$-0.002$ $\pm0.018$ $\pm0.003$ 137k 2
 1996 D
$-0.015$ $\pm0.017$ $\pm0.025$ 272k 3
 1994
SPEC
1  ADLER 1997B also find Re($\eta _{+−0}$) = $-0.002$ $\pm0.007$ ${}^{+0.004}_{-0.001}$. See also ANGELOPOULOS 1998C.
2  The ADLER 1996D fit also yields Re($\eta _{+−0}$) = $0.006$ $\pm0.013$ $\pm0.001$ with a correlation $+0.66$ between real and imaginary parts. Their results correspond to $\vert \eta _{+−0}\vert <0.037$ with 90$\%$ CL.
3  ZOU 1994 use theoretical constraint Re($\eta _{+−0}$) = Re($\epsilon$) = $0.0016$. Without this constraint they find Im($\eta _{+−0}$) = $0.019$ $\pm0.061$ and Re($\eta _{+−0}$) = $0.019$ $\pm0.027$.
Conservation Laws:
 $\mathit CP$ INVARIANCE
References:
PL B407 193 CPLEAR Results on the $\mathit CP$ Parameters of Neutral Kaons Decaying to ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$
PL B370 167 Search for $\mathit CP$ Violation in the Decay of Neutral Kaons to ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$
PL B329 519 Search for $\mathit CP$ Violation in the Decay ${{\mathit K}_S^0}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$