Test of $CPT$ Symmetry in $CP$-violating $B$ Decays

Abstract

Considering that the existing experimental limit for $CPT$ violation is still poor, we explore various possible ways to test $CPT$ symmetry in $CP$-violating $B$ decays at $e^{+}{e}^{-}$ $B$ factories. We find that it is difficult to distinguish between the effect of direct $CP$ violation and that of $CPT$ violation in the time-integrated measurements of neutral $B$ decays to $CP$ eigenstates such as $\psi K_S$ and ${\pi }^{+}{\pi }^{-}$. Instead, a cleaner signal of small $CPT$ violation may appear in the time-integrated $CP$ asymmetries for a few non-$CP$-eigenstate channels, e.g., $B_d^0/{\bar{B}}_d^0\to D^{\pm }{\pi }^{\mp }$ and $\stackrel{(-)}{D}$${}^{(\ast )0}{K}_S$. The time-dependent measurements of $CP$ asymmetries are available, in principle, to limit the size of $CPT$-violating effects in neutral $B$-meson decays.

Comments: 10 Latex pages; LMU-02/94 (shortened version)