Direct CP Violation in Untagged B-Meson Decays

Direct CP violation can exist in untagged, neutral B-meson decays to certain self-conjugate, hadronic final states. As a necessary condition, the resonances which appear therein must permit the identification of distinct, CP-conjugate states — in analogy to stereochemistry, we term such states “CP-enantiomers.” These states permit the construction of CP-even and CP-odd amplitude combinations and of observables sensitive to their interference, which are non-zero if direct CP violation is present. The decay B → π+π−π0, containing the distinct CP-conjugate states ρ+π− and ρ−π+, provides one such example of a CP-enantiomeric pair. We illustrate the possibilities in various multi-particle final states.