CPNonconservation andCPT: Reassessment of Loop Effects in CharmlessBDecays

Absorptive parts in QCD-induced charmless $B$ decays allow for a new mechanism of $\mathrm{CP}$ violation. Existing discussions in the literature do not satisfy the $\mathrm{CPT}$ theorem. Solving the problem, we find that, inclusively, a strong cancellation remains between the $b\to \mathrm{su}\overline{u}$ mode $\mathrm{CP}$ rate asymmetries and the purely loop-induced $b\to \mathrm{sd}\overline{d}, \mathrm{ss}\overline{s}, \mathrm{sgg}$ modes. Exclusively, the asymmetries of purely loop-induced modes (such as $B\to K\phi$) are unaffected, but those related to $b\to \mathrm{su}\overline{u}$ (such as $B\to K\pi$) change sign. The discussion for $b\to d$ modes is similar.