In ${{\mathit K}^{0}}-{{\overline{\mathit K}}^{0}}$ mixing, if $\mathit CP$-violating interactions include a $\mathit T$ conserving part then

$|{{\mathit K}_{{{S}}}}\rangle{}$ = [$|{{\mathit K}_{{{1}}}}\rangle{}+(\epsilon +\delta )|{{\mathit K}_{{{2}}}}\rangle{}]/\sqrt {1+\vert \epsilon +\delta \vert ^2 }$

$|{{\mathit K}_{{{L}}}}\rangle{}$ = [$|{{\mathit K}_{{{2}}}}\rangle{}+(\epsilon −\delta )|{{\mathit K}_{{{1}}}}\rangle{}]/\sqrt {1+\vert \epsilon −\delta \vert ^2 }$

where

$|{{\mathit K}_{{{1}}}}\rangle{}$ = [$|{{\mathit K}^{0}}\rangle{}+|{{\overline{\mathit K}}^{0}}\rangle{}]/\sqrt {2 }$

$|{{\mathit K}_{{{2}}}}\rangle{}$ = [$|{{\mathit K}^{0}}\rangle{}−|{{\overline{\mathit K}}^{0}}\rangle{}]/\sqrt {2 }$

and

$|{{\overline{\mathit K}}^{0}}\rangle{}$ = $\mathit CP|{{\mathit K}^{0}}\rangle{}$.

The parameter $\delta $ specifies the $\mathit CPT$-violating part.
Estimates of $\delta $ are given below assuming the validity of the $\Delta \mathit S=\Delta \mathit Q$ rule. See also THOMSON 1995 for a test of $\mathit CPT$-symmetry conservation in ${{\mathit K}^{0}}$ decays using the Bell-Steinberger relation.