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 ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ B factories. We find that it is difficult to distinguish between the effect of direct CP violation and that of CPT violation in the time-integrated measurements of neutral B decays to CP eigenstates such as \ensuremath{\psi}${\mathit{K}}_{\mathit{S}}$ and ${\mathrm{\ensuremath{\pi}}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$. 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${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathit{d}}^{0}$ \ensuremath{\rightarrow} ${\mathit{D}}^{\ifmmode\pm\else\textpm\fi{}}$${\mathrm{\ensuremath{\pi}}}^{\ensuremath{\mp}}$ and ${\mathit{D}}^{(\mathrm{\ensuremath{-}})(\mathrm{*})0}$${\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.