Testing New IndirectCPViolation

If new $CP$ violating physics contributes to neutral meson mixing, but its contribution to $CP$ violation in decay amplitudes is negligible, then there is a model independent relation between four (generally independent) observables related to the mixing: the mass splitting ($x$), the width splitting ($y$), the $CP$ violation in mixing ($1-|q/p|$), and the $CP$ violation in the interference of decays with and without mixing ($\varphi$). For the four neutral meson systems, this relation can be written in a simple approximate form: $y\tan \varphi \approx x(1-|q/p|)$. In the $K$ system, all four observables have been measured and obey the relation to excellent accuracy. For the $B_s$ and $D$ systems, new predictions are provided. The success or failure of these relations will probe the physics that is responsible for the $CP$ violation.