Abstract
The density matrix ρ describing a decaying system can be expressed in terms of correlations among observables belonging to the subsystems. Due to this structure and to the difficulties in measuring higher rank tensors of decay products for a single decay event, it is found that the mean value of ρ cannot be determined, in general, from measurements on the decay products. We also discuss the consequences of this conclusion as far as tests of quantum mechanics are concerned.
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Bergia, S., Cannata, F., Cornia, A. et al. On the actual measurability of the density matrix of a decaying system by means of measurements on the decay products. Found Phys 10, 723–730 (1980). https://doi.org/10.1007/BF00708418
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DOI: https://doi.org/10.1007/BF00708418