Correlated neutral β meson decays into CP eigenstates

In the two correlated B meson decay experiment we propose to measure intensities relating CP eigenstate (J/psiK(S,L)) decays on both sides, which will be measurable in future upgrades of KEK and PEP. As a CP-forbidden transition, we obtain I(J/psi K-S, J/psi K-S, Deltat) similar to sin(2)(2beta). We calculate in a model independent way all the possible intensities relating final CP and flavour eigenstate decays. Under CPT-invariance, the asymmetries for processes related by CPDeltat vanish for DeltaGamma = 0 and measure DeltaGamma linearly. We notice the impossibility to isolate the sign of cos(2beta) without an independent knowledge of the sign of A F. This exhaustion of the possible golden plate and flavour decays provides new observables which may throw light in our present understanding of CKM physics. (C) 2003 Published by Elsevier B.V.