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 ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{-}}$ B factories. We find that it is difficult to distinguish between the effect of direct CP violation and that of CPT violation in the time-integrated measurements of neutral B decays to CP eigenstates such as ψ${\mathit{K}}_{\mathit{S}}$ and ${\mathrm{\pi }}^{+}$${\mathrm{\pi }}^{\mathrm{-}}$. 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., ${\mathit{B}}_{\mathit{d}}^0$ /B${\mathrm{¯}}_{\mathit{d}}^0$ → ${\mathit{D}}^{\pm }$${\mathrm{\pi }}^{\mp }$ and ${\mathit{D}}^{\left(\mathrm{-}\right)\left(\mathrm{*}\right)0\mathrm{}}$${\mathit{K}}_{\mathit{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.

DOI:https://doi.org/10.1103/PhysRevD.50.R2957