B − B̄ entanglement for an ideal experiment on the direct CP violation φ3/γ phase

B–B̄ Entanglement offers a conceptual alternative to the single charged B-decay asymmetry for the measurement of the direct CP violating γ/φ3 phase. With f = J/ΨKL, J/ΨKS and g = (ππ), (ρLρL) 0 the 16 time-ordered double decay rate Intensities to (f, g) depend on the relative phase between the the f and g-decay amplitudes given by γ at tree-level. Several constraining consistencies appear. An intrinsic accuracy of the method at the level of ±1◦ could be achievable at Belle-II with an improved determination of the penguin amplitude to g-channels from existing facilities.